wasm: use wasip1 API for parameter/env passing

Instead of hardcoding the command line parameters and the environment
variables in the binary, pass them at runtime to Node.js and use the
WASIp1 API to retrieve them in wasm_exec.js.

The only real benefit right now is that it becomes possible to change
`go.argv` and `go.env` before running a wasm binary.

This also changes the syscall package for GOOS=js: it now becomes more
like a libc (using wasi-libc), which means error values like
`syscall.EEXIST` will actually match the one returned by the relevant
libc function.

Wasm binary size for packages that import the os package will be
increased somewhat.

.github/FUNDING.yml

@@ -0,0 +1,3 @@
+# These are supported funding model platforms
+
+open_collective: tinygo

.github/workflows/build-macos.yml

@@ -16,18 +16,17 @@ jobs:
     name: build-macos
     strategy:
       matrix:
-        # macos-12: amd64 (oldest supported version as of 05-02-2024)
+        # macos-13: amd64 (oldest supported version as of 18-10-2024)
         # macos-14: arm64 (oldest arm64 version)
-        os: [macos-12, macos-14]
+        os: [macos-13, macos-14]
         include:
-          - os: macos-12
+          - os: macos-13
             goarch: amd64
           - os: macos-14
             goarch: arm64
     runs-on: ${{ matrix.os }}
     steps:
       - name: Install Dependencies
-        shell: bash
         run: |
           HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu binaryen
       - name: Checkout
@@ -72,7 +71,6 @@ jobs:
           path: llvm-build
       - name: Build LLVM
         if: steps.cache-llvm-build.outputs.cache-hit != 'true'
-        shell: bash
         run: |
           # fetch LLVM source
           rm -rf llvm-project
@@ -100,14 +98,12 @@ jobs:
       - name: make gen-device
         run: make -j3 gen-device
       - name: Test TinyGo
-        shell: bash
         run: make test GOTESTFLAGS="-short"
       - name: Build TinyGo release tarball
         run: make release -j3
       - name: Test stdlib packages
         run: make tinygo-test
       - name: Make release artifact
-        shell: bash
         run: cp -p build/release.tar.gz build/tinygo.darwin-${{ matrix.goarch }}.tar.gz
       - name: Publish release artifact
         # Note: this release artifact is double-zipped, see:
@@ -121,7 +117,6 @@ jobs:
           name: darwin-${{ matrix.goarch }}-double-zipped
           path: build/tinygo.darwin-${{ matrix.goarch }}.tar.gz
       - name: Smoke tests
-        shell: bash
         run: make smoketest TINYGO=$(PWD)/build/tinygo
   test-macos-homebrew:
     name: homebrew-install

.github/workflows/nix.yml

@@ -15,6 +15,11 @@ jobs:
   nix-test:
     runs-on: ubuntu-latest
     steps:
+      - name: Uninstall system LLVM
+        # Hack to work around issue where we still include system headers for
+        # some reason.
+        # See: https://github.com/tinygo-org/tinygo/pull/4516#issuecomment-2416363668
+        run: sudo apt-get remove llvm-18
       - name: Checkout
         uses: actions/checkout@v4
       - name: Pull musl

.gitignore

@@ -20,6 +20,8 @@ src/device/stm32/*.go
 src/device/stm32/*.s
 src/device/kendryte/*.go
 src/device/kendryte/*.s
+src/device/renesas/*.go
+src/device/renesas/*.s
 src/device/rp/*.go
 src/device/rp/*.s
 ./vendor

.gitmodules

@@ -32,9 +32,6 @@
 [submodule "lib/macos-minimal-sdk"]
 	path = lib/macos-minimal-sdk
 	url = https://github.com/aykevl/macos-minimal-sdk.git
-[submodule "lib/renesas-svd"]
-	path = lib/renesas-svd
-	url = https://github.com/tinygo-org/renesas-svd.git
 [submodule "src/net"]
 	path = src/net
 	url = https://github.com/tinygo-org/net.git

CHANGELOG.md

@@ -1,3 +1,53 @@
+0.34.0
+---
+* **general**
+  - fix `GOOS=wasip1` for `tinygo test`
+  - add `-C DIR` flag
+  - add initial documentation for project governance
+  - add `-ldflags='-extldflags=...'` support
+  - improve usage message with `tinygo help` and when passing invalid parameters
+* **compiler**
+  - `builder`: remove environment variables when invoking Clang, to avoid the environment changing the behavior
+  - `builder`: check for the Go toolchain version used to compile TinyGo
+  - `cgo`: add `C.CBytes` implementation
+  - `compiler`: fix passing weirdly-padded structs as parameters to new goroutines
+  - `compiler`: support pragmas on generic functions
+  - `compiler`: do not let the slice buffer escape when casting a `[]byte` or `[]rune` to a string, to help escape analysis
+  - `compiler`: conform to the latest iteration of the wasm types proposal
+  - `loader`: don't panic when main package is not named 'main'
+  - `loader`: make sure we always return type checker errors even without type errors
+  - `transform`: optimize range over `[]byte(string)`
+* **standard library**
+  - `crypto/x509`: add package stub to build crypto/x509 on macOS
+  - `machine/usb/adc/midi`: fix `PitchBend`
+  - `os`: add `Truncate` stub for baremetal
+  - `os`: add stubs for `os.File` deadlines
+  - `os`: add internal `net.newUnixFile` for the net package
+  - `runtime`: stub runtime_{Before,After}Exec for linkage
+  - `runtime`: randomize map accesses
+  - `runtime`: support `maps.Clone`
+  - `runtime`: add more fields to `MemStats`
+  - `runtime`: implement newcoro, coroswitch to support package iter
+  - `runtime`: disallow defer in interrupts
+  - `runtime`: add support for os/signal on Linux and MacOS
+  - `runtime`: add gc layout info for some basic types to help the precise GC
+  - `runtime`: bump GC mark stack size to avoid excessive heap rescans
+* **targets**
+  - `darwin`: use Go standard library syscall package instead of a custom one
+  - `fe310`: support GPIO `PinInput`
+  - `mips`: fix compiler crash with GOMIPS=softfloat and defer
+  - `mips`: add big-endian (GOARCH=mips) support
+  - `mips`: use MIPS32 (instead of MIPS32R2) as the instruction set for wider compatibility
+  - `wasi`: add relative and absolute --dir options to wasmtime args
+  - `wasip2`: add wasmtime -S args to support network interfaces
+  - `wasm`: add `//go:wasmexport` support (for all WebAssembly targets)
+  - `wasm`: use precise instead of conservative GC for WebAssembly (including WASI)
+  - `wasm-unknown`: add bulk memory flags since basically every runtime has it now
+* **boards**
+  - add RAKwireless RAK4631
+  - add WaveShare ESP-C3-32S-Kit
+
+
 0.33.0
 ---
 

GNUmakefile

@@ -185,7 +185,7 @@ fmt-check: ## Warn if any source needs reformatting
 	@unformatted=$$(gofmt -l $(FMT_PATHS)); [ -z "$$unformatted" ] && exit 0; echo "Unformatted:"; for fn in $$unformatted; do echo "  $$fn"; done; exit 1
 
 
-gen-device: gen-device-avr gen-device-esp gen-device-nrf gen-device-sam gen-device-sifive gen-device-kendryte gen-device-nxp gen-device-rp ## Generate microcontroller-specific sources
+gen-device: gen-device-avr gen-device-esp gen-device-nrf gen-device-sam gen-device-sifive gen-device-kendryte gen-device-nxp gen-device-rp gen-device-renesas ## Generate microcontroller-specific sources
 ifneq ($(STM32), 0)
 gen-device: gen-device-stm32
 endif
@@ -234,7 +234,7 @@ gen-device-rp: build/gen-device-svd
 	GO111MODULE=off $(GO) fmt ./src/device/rp
 
 gen-device-renesas: build/gen-device-svd
-	./build/gen-device-svd -source=https://github.com/tinygo-org/renesas-svd lib/renesas-svd/ src/device/renesas/
+	./build/gen-device-svd -source=https://github.com/cmsis-svd/cmsis-svd-data/tree/master/data/Renesas lib/cmsis-svd/data/Renesas/ src/device/renesas/
 	GO111MODULE=off $(GO) fmt ./src/device/renesas
 
 $(LLVM_PROJECTDIR)/llvm:
@@ -267,7 +267,7 @@ lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a:
 	cd lib/wasi-libc && $(MAKE) -j4 EXTRA_CFLAGS="-O2 -g -DNDEBUG -mnontrapping-fptoint -msign-ext" MALLOC_IMPL=none CC="$(CLANG)" AR=$(LLVM_AR) NM=$(LLVM_NM)
 
 # Generate WASI syscall bindings
-WASM_TOOLS_MODULE=github.com/ydnar/wasm-tools-go
+WASM_TOOLS_MODULE=github.com/bytecodealliance/wasm-tools-go
 .PHONY: wasi-syscall
 wasi-syscall: wasi-cm
 	go run -modfile ./internal/wasm-tools/go.mod $(WASM_TOOLS_MODULE)/cmd/wit-bindgen-go generate --versioned -o ./src/internal -p internal --cm internal/cm ./lib/wasi-cli/wit
@@ -293,7 +293,7 @@ tinygo: ## Build the TinyGo compiler
 	@if [ ! -f "$(LLVM_BUILDDIR)/bin/llvm-config" ]; then echo "Fetch and build LLVM first by running:"; echo "  $(MAKE) llvm-source"; echo "  $(MAKE) $(LLVM_BUILDDIR)"; exit 1; fi
 	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GOENVFLAGS) $(GO) build -buildmode exe -o build/tinygo$(EXE) -tags "byollvm osusergo" -ldflags="-X github.com/tinygo-org/tinygo/goenv.GitSha1=`git rev-parse --short HEAD`" .
 test: wasi-libc check-nodejs-version
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test $(GOTESTFLAGS) -timeout=20m -buildmode exe -tags "byollvm osusergo" $(GOTESTPKGS)
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test $(GOTESTFLAGS) -timeout=1h -buildmode exe -tags "byollvm osusergo" $(GOTESTPKGS)
 
 # Standard library packages that pass tests on darwin, linux, wasi, and windows, but take over a minute in wasi
 TEST_PACKAGES_SLOW = \
@@ -303,26 +303,34 @@ TEST_PACKAGES_SLOW = \
 
 # Standard library packages that pass tests quickly on darwin, linux, wasi, and windows
 TEST_PACKAGES_FAST = \
+	cmp \
 	compress/lzw \
 	compress/zlib \
 	container/heap \
 	container/list \
 	container/ring \
 	crypto/des \
+	crypto/ecdsa \
+	crypto/elliptic \
 	crypto/md5 \
 	crypto/rc4 \
 	crypto/sha1 \
 	crypto/sha256 \
 	crypto/sha512 \
+	database/sql/driver \
 	debug/macho \
 	embed/internal/embedtest \
 	encoding \
 	encoding/ascii85 \
+	encoding/asn1 \
 	encoding/base32 \
 	encoding/base64 \
 	encoding/csv \
 	encoding/hex \
+	go/ast \
+	go/format \
 	go/scanner \
+	go/version \
 	hash \
 	hash/adler32 \
 	hash/crc64 \
@@ -357,11 +365,17 @@ endif
 # archive/zip requires os.ReadAt, which is not yet supported on windows
 # bytes requires mmap
 # compress/flate appears to hang on wasi
+# crypto/aes fails on wasi, needs panic()/recover()
 # crypto/hmac fails on wasi, it exits with a "slice out of range" panic
 # debug/plan9obj requires os.ReadAt, which is not yet supported on windows
 # image requires recover(), which is not yet supported on wasi
 # io/ioutil requires os.ReadDir, which is not yet supported on windows or wasi
+# mime: fail on wasi; neds panic()/recover()
+# mime/multipart: needs wasip1 syscall.FDFLAG_NONBLOCK
 # mime/quotedprintable requires syscall.Faccessat
+# net/mail: needs wasip1  syscall.FDFLAG_NONBLOCK
+# net/ntextproto: needs wasip1 syscall.FDFLAG_NONBLOCK
+# regexp/syntax: fails on wasip1; needs panic()/recover()
 # strconv requires recover() which is not yet supported on wasi
 # text/tabwriter requires recover(), which is not yet supported on wasi
 # text/template/parse requires recover(), which is not yet supported on wasi
@@ -371,14 +385,20 @@ endif
 TEST_PACKAGES_LINUX := \
 	archive/zip \
 	compress/flate \
+	crypto/aes \
 	crypto/hmac \
 	debug/dwarf \
 	debug/plan9obj \
 	image \
 	io/ioutil \
+	mime \
+	mime/multipart \
 	mime/quotedprintable \
 	net \
+	net/mail \
+	net/textproto \
 	os/user \
+	regexp/syntax \
 	strconv \
 	text/tabwriter \
 	text/template/parse
@@ -483,8 +503,17 @@ tinygo-baremetal:
 	# regression test for #2666: e.g. encoding/hex must pass on baremetal
 	$(TINYGO) test -target cortex-m-qemu encoding/hex
 
+.PHONY: testchdir
+testchdir:
+	# test 'build' command with{,out} -C argument
+	$(TINYGO) build -C tests/testing/chdir chdir.go && rm tests/testing/chdir/chdir
+	$(TINYGO) build ./tests/testing/chdir/chdir.go && rm chdir
+	# test 'run' command with{,out} -C argument
+	EXPECT_DIR=$(PWD)/tests/testing/chdir $(TINYGO) run -C tests/testing/chdir chdir.go
+	EXPECT_DIR=$(PWD) $(TINYGO) run ./tests/testing/chdir/chdir.go
+
 .PHONY: smoketest
-smoketest:
+smoketest: testchdir
 	$(TINYGO) version
 	$(TINYGO) targets > /dev/null
 	# regression test for #2892
@@ -642,6 +671,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=xiao                examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=rak4631             examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/dac
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/dac
@@ -804,12 +835,20 @@ ifneq ($(XTENSA), 0)
 	$(TINYGO) build -size short -o test.bin -target mch2022             examples/machinetest
 	@$(MD5SUM) test.bin
 endif
+	$(TINYGO) build -size short -o test.bin -target=esp-c3-32s-kit      examples/blinky1
+	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=qtpy-esp32c3        examples/machinetest
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=m5stamp-c3          examples/machinetest
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target=xiao-esp32c3        examples/machinetest
 	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32-c3-devkit-rust-1 examples/blinky1
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=esp32c3-12f         examples/blinky1
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=makerfabs-esp32c3spi35 examples/machinetest
+	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=maixbit             examples/blinky1

GOVERNANCE.md

@@ -0,0 +1,32 @@
+TinyGo Team Members
+===================
+
+The team of humans who maintain TinyGo.
+
+*   **Purpose**: To maintain the community, code, documentation, and tools for the TinyGo compiler.
+*   **Board**: The group of people who share responsibility for key decisions for the TinyGo organization.  
+    *   **Majority Voting**: The board makes decisions by majority vote.
+    *   **Membership**: The board elects its own members.
+*   **Do-ocracy**: Those who step forward to do a given task propose how it should be done. Then other interested people can make comments.
+*   **Proof of Work**: Power in decision-making is slightly weighted based on a participant's labor for the community.
+*   **Initiation**: We need to establish a procedure for how people join the team of maintainers.
+*   **Transparency**: Important information should be made publicly available, ideally in a way that allows for public comment.
+*   **Code of Conduct**: Participants agree to abide by the current project Code of Conduct.
+
+## Members
+
+* Ayke van Laethem (@aykevl)
+* Daniel Esteban (@conejoninja)
+* Ron Evans (@deadprogram)
+* Damian Gryski (@dgryski)
+* Masaaki Takasago (@sago35)
+* Patricio Whittingslow (@soypat)
+* Yurii Soldak (@ysoldak)
+
+## Experimental
+
+*   **Monthly Meeting**: A monthly meeting for the team and any other interested participants.  
+    Duration: 1 hour  
+    Facilitation: @deadprogram
+    Schedule: See https://github.com/tinygo-org/tinygo/wiki/Meetings for more information
+

builder/build.go

@@ -197,6 +197,7 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 		ABI:             config.ABI(),
 		GOOS:            config.GOOS(),
 		GOARCH:          config.GOARCH(),
+		BuildMode:       config.BuildMode(),
 		CodeModel:       config.CodeModel(),
 		RelocationModel: config.RelocationModel(),
 		SizeLevel:       sizeLevel,
@@ -649,6 +650,13 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 	result.Binary = result.Executable // final file
 	ldflags := append(config.LDFlags(), "-o", result.Executable)
 
+	if config.Options.BuildMode == "c-shared" {
+		if !strings.HasPrefix(config.Triple(), "wasm32-") {
+			return result, fmt.Errorf("buildmode c-shared is only supported on wasm at the moment")
+		}
+		ldflags = append(ldflags, "--no-entry")
+	}
+
 	// Add compiler-rt dependency if needed. Usually this is a simple load from
 	// a cache.
 	if config.Target.RTLib == "compiler-rt" {
@@ -823,19 +831,13 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 					args = append(args, "--asyncify")
 				}
 
-				exeunopt := result.Executable
-
-				if config.Options.Work {
-					// Keep the work direction around => don't overwrite the .wasm binary with the optimized version
-					exeunopt += ".pre-wasm-opt"
-					os.Rename(result.Executable, exeunopt)
-				}
-
+				inputFile := result.Binary
+				result.Binary = result.Executable + ".wasmopt"
 				args = append(args,
 					opt,
 					"-g",
-					exeunopt,
-					"--output", result.Executable,
+					inputFile,
+					"--output", result.Binary,
 				)
 
 				wasmopt := goenv.Get("WASMOPT")
@@ -865,13 +867,15 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 
 				// wasm-tools component embed -w wasi:cli/command
 				// 		$$(tinygo env TINYGOROOT)/lib/wasi-cli/wit/ main.wasm -o embedded.wasm
+				componentEmbedInputFile := result.Binary
+				result.Binary = result.Executable + ".wasm-component-embed"
 				args := []string{
 					"component",
 					"embed",
 					"-w", witWorld,
 					witPackage,
-					result.Executable,
-					"-o", result.Executable,
+					componentEmbedInputFile,
+					"-o", result.Binary,
 				}
 
 				wasmtools := goenv.Get("WASMTOOLS")
@@ -884,15 +888,17 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 
 				err := cmd.Run()
 				if err != nil {
-					return fmt.Errorf("wasm-tools failed: %w", err)
+					return fmt.Errorf("`wasm-tools component embed` failed: %w", err)
 				}
 
 				// wasm-tools component new embedded.wasm -o component.wasm
+				componentNewInputFile := result.Binary
+				result.Binary = result.Executable + ".wasm-component-new"
 				args = []string{
 					"component",
 					"new",
-					result.Executable,
-					"-o", result.Executable,
+					componentNewInputFile,
+					"-o", result.Binary,
 				}
 
 				if config.Options.PrintCommands != nil {
@@ -904,7 +910,7 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 
 				err = cmd.Run()
 				if err != nil {
-					return fmt.Errorf("wasm-tools failed: %w", err)
+					return fmt.Errorf("`wasm-tools component new` failed: %w", err)
 				}
 			}
 

builder/commands.go

@@ -3,7 +3,6 @@ package builder
 import (
 	"errors"
 	"fmt"
-	"os"
 	"os/exec"
 	"runtime"
 	"strings"
@@ -76,14 +75,3 @@ func LookupCommand(name string) (string, error) {
 	}
 	return "", errors.New("none of these commands were found in your $PATH: " + strings.Join(commands[name], " "))
 }
-
-func execCommand(name string, args ...string) error {
-	name, err := LookupCommand(name)
-	if err != nil {
-		return err
-	}
-	cmd := exec.Command(name, args...)
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	return cmd.Run()
-}

builder/config.go

@@ -2,6 +2,7 @@ package builder
 
 import (
 	"fmt"
+	"runtime"
 
 	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/goenv"
@@ -23,20 +24,37 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 		spec.OpenOCDCommands = options.OpenOCDCommands
 	}
 
-	major, minor, err := goenv.GetGorootVersion()
+	// Version range supported by TinyGo.
+	const minorMin = 19
+	const minorMax = 23
+
+	// Check that we support this Go toolchain version.
+	gorootMajor, gorootMinor, err := goenv.GetGorootVersion()
 	if err != nil {
 		return nil, err
 	}
-	if major != 1 || minor < 19 || minor > 23 {
+	if gorootMajor != 1 || gorootMinor < minorMin || gorootMinor > minorMax {
 		// Note: when this gets updated, also update the Go compatibility matrix:
 		// https://github.com/tinygo-org/tinygo-site/blob/dev/content/docs/reference/go-compat-matrix.md
-		return nil, fmt.Errorf("requires go version 1.19 through 1.23, got go%d.%d", major, minor)
+		return nil, fmt.Errorf("requires go version 1.19 through 1.23, got go%d.%d", gorootMajor, gorootMinor)
+	}
+
+	// Check that the Go toolchain version isn't too new, if we haven't been
+	// compiled with the latest Go version.
+	// This may be a bit too aggressive: if the newer version doesn't change the
+	// Go language we will most likely be able to compile it.
+	buildMajor, buildMinor, _, err := goenv.Parse(runtime.Version())
+	if err != nil {
+		return nil, err
+	}
+	if buildMajor != 1 || buildMinor < gorootMinor {
+		return nil, fmt.Errorf("cannot compile with Go toolchain version go%d.%d (TinyGo was built using toolchain version %s)", gorootMajor, gorootMinor, runtime.Version())
 	}
 
 	return &compileopts.Config{
 		Options:        options,
 		Target:         spec,
-		GoMinorVersion: minor,
+		GoMinorVersion: gorootMinor,
 		TestConfig:     options.TestConfig,
 	}, nil
 }

builder/jobs.go

@@ -17,14 +17,6 @@ import (
 // concurrency or performance issues.
 const jobRunnerDebug = false
 
-type jobState uint8
-
-const (
-	jobStateQueued   jobState = iota // not yet running
-	jobStateRunning                  // running
-	jobStateFinished                 // finished running
-)
-
 // compileJob is a single compiler job, comparable to a single Makefile target.
 // It is used to orchestrate various compiler tasks that can be run in parallel
 // but that have dependencies and thus have limitations in how they can be run.
@@ -55,12 +47,11 @@ func dummyCompileJob(result string) *compileJob {
 // ordered as such in the job dependencies.
 func runJobs(job *compileJob, sema chan struct{}) error {
 	if sema == nil {
-		// Have a default, if the semaphore isn't set. This is useful for
-		// tests.
+		// Have a default, if the semaphore isn't set. This is useful for tests.
 		sema = make(chan struct{}, runtime.NumCPU())
 	}
 	if cap(sema) == 0 {
-		return errors.New("cannot 0 jobs at a time")
+		return errors.New("cannot run 0 jobs at a time")
 	}
 
 	// Create a slice of jobs to run, where all dependencies are run in order.
@@ -81,10 +72,10 @@ func runJobs(job *compileJob, sema chan struct{}) error {
 
 	waiting := make(map[*compileJob]map[*compileJob]struct{}, len(jobs))
 	dependents := make(map[*compileJob][]*compileJob, len(jobs))
-	jidx := make(map[*compileJob]int)
+	compileJobs := make(map[*compileJob]int)
 	var ready intHeap
 	for i, job := range jobs {
-		jidx[job] = i
+		compileJobs[job] = i
 		if len(job.dependencies) == 0 {
 			// This job is ready to run.
 			ready.Push(i)
@@ -105,8 +96,7 @@ func runJobs(job *compileJob, sema chan struct{}) error {
 	// Create a channel to accept notifications of completion.
 	doneChan := make(chan *compileJob)
 
-	// Send each job in the jobs slice to a worker, taking care of job
-	// dependencies.
+	// Send each job in the jobs slice to a worker, taking care of job dependencies.
 	numRunningJobs := 0
 	var totalTime time.Duration
 	start := time.Now()
@@ -156,7 +146,7 @@ func runJobs(job *compileJob, sema chan struct{}) error {
 			delete(wait, completed)
 			if len(wait) == 0 {
 				// This job is now ready to run.
-				ready.Push(jidx[j])
+				ready.Push(compileJobs[j])
 				delete(waiting, j)
 			}
 		}

builder/musl.go

@@ -128,6 +128,7 @@ var libMusl = Library{
 			"mman/*.c",
 			"math/*.c",
 			"multibyte/*.c",
+			"signal/" + arch + "/*.s",
 			"signal/*.c",
 			"stdio/*.c",
 			"string/*.c",

builder/sizes_test.go

@@ -41,9 +41,9 @@ func TestBinarySize(t *testing.T) {
 	// This is a small number of very diverse targets that we want to test.
 	tests := []sizeTest{
 		// microcontrollers
-		{"hifive1b", "examples/echo", 4484, 280, 0, 2252},
-		{"microbit", "examples/serial", 2732, 388, 8, 2256},
-		{"wioterminal", "examples/pininterrupt", 6016, 1484, 116, 6816},
+		{"hifive1b", "examples/echo", 4568, 280, 0, 2268},
+		{"microbit", "examples/serial", 2868, 388, 8, 2272},
+		{"wioterminal", "examples/pininterrupt", 6104, 1484, 116, 6832},
 
 		// TODO: also check wasm. Right now this is difficult, because
 		// wasm binaries are run through wasm-opt and therefore the

builder/tools.go

@@ -14,16 +14,29 @@ import (
 
 // runCCompiler invokes a C compiler with the given arguments.
 func runCCompiler(flags ...string) error {
+	// Find the right command to run Clang.
+	var cmd *exec.Cmd
 	if hasBuiltinTools {
 		// Compile this with the internal Clang compiler.
-		cmd := exec.Command(os.Args[0], append([]string{"clang"}, flags...)...)
-		cmd.Stdout = os.Stdout
-		cmd.Stderr = os.Stderr
-		return cmd.Run()
+		cmd = exec.Command(os.Args[0], append([]string{"clang"}, flags...)...)
+	} else {
+		// Compile this with an external invocation of the Clang compiler.
+		name, err := LookupCommand("clang")
+		if err != nil {
+			return err
+		}
+		cmd = exec.Command(name, flags...)
 	}
 
-	// Compile this with an external invocation of the Clang compiler.
-	return execCommand("clang", flags...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	// Make sure the command doesn't use any environmental variables.
+	// Most importantly, it should not use C_INCLUDE_PATH and the like. But
+	// removing all environmental variables also works.
+	cmd.Env = []string{}
+
+	return cmd.Run()
 }
 
 // link invokes a linker with the given name and flags.

cgo/cgo.go

@@ -162,6 +162,13 @@ func __GoBytes(unsafe.Pointer, uintptr) []byte
 func GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 	return C.__GoBytes(ptr, uintptr(length))
 }
+
+//go:linkname C.__CBytes runtime.cgo_CBytes
+func __CBytes([]byte) unsafe.Pointer
+
+func CBytes(b []byte) unsafe.Pointer {
+	return C.__CBytes(b)
+}
 `
 
 // Process extracts `import "C"` statements from the AST, parses the comment
@@ -218,7 +225,7 @@ func Process(files []*ast.File, dir, importPath string, fset *token.FileSet, cfl
 		switch decl := decl.(type) {
 		case *ast.FuncDecl:
 			switch decl.Name.Name {
-			case "CString", "GoString", "GoStringN", "__GoStringN", "GoBytes", "__GoBytes":
+			case "CString", "GoString", "GoStringN", "__GoStringN", "GoBytes", "__GoBytes", "CBytes", "__CBytes":
 				// Adjust the name to have a "C." prefix so it is correctly
 				// resolved.
 				decl.Name.Name = "C." + decl.Name.Name

cgo/testdata/basic.out.go

@@ -24,6 +24,13 @@ func C.GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 	return C.__GoBytes(ptr, uintptr(length))
 }
 
+//go:linkname C.__CBytes runtime.cgo_CBytes
+func C.__CBytes([]byte) unsafe.Pointer
+
+func C.CBytes(b []byte) unsafe.Pointer {
+	return C.__CBytes(b)
+}
+
 type (
 	C.char      uint8
 	C.schar     int8

cgo/testdata/const.out.go

@@ -24,6 +24,13 @@ func C.GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 	return C.__GoBytes(ptr, uintptr(length))
 }
 
+//go:linkname C.__CBytes runtime.cgo_CBytes
+func C.__CBytes([]byte) unsafe.Pointer
+
+func C.CBytes(b []byte) unsafe.Pointer {
+	return C.__CBytes(b)
+}
+
 type (
 	C.char      uint8
 	C.schar     int8

cgo/testdata/errors.out.go

@@ -44,6 +44,13 @@ func C.GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 	return C.__GoBytes(ptr, uintptr(length))
 }
 
+//go:linkname C.__CBytes runtime.cgo_CBytes
+func C.__CBytes([]byte) unsafe.Pointer
+
+func C.CBytes(b []byte) unsafe.Pointer {
+	return C.__CBytes(b)
+}
+
 type (
 	C.char      uint8
 	C.schar     int8

cgo/testdata/flags.out.go

@@ -29,6 +29,13 @@ func C.GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 	return C.__GoBytes(ptr, uintptr(length))
 }
 
+//go:linkname C.__CBytes runtime.cgo_CBytes
+func C.__CBytes([]byte) unsafe.Pointer
+
+func C.CBytes(b []byte) unsafe.Pointer {
+	return C.__CBytes(b)
+}
+
 type (
 	C.char      uint8
 	C.schar     int8

cgo/testdata/symbols.out.go

@@ -24,6 +24,13 @@ func C.GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 	return C.__GoBytes(ptr, uintptr(length))
 }
 
+//go:linkname C.__CBytes runtime.cgo_CBytes
+func C.__CBytes([]byte) unsafe.Pointer
+
+func C.CBytes(b []byte) unsafe.Pointer {
+	return C.__CBytes(b)
+}
+
 type (
 	C.char      uint8
 	C.schar     int8

cgo/testdata/types.out.go

@@ -24,6 +24,13 @@ func C.GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 	return C.__GoBytes(ptr, uintptr(length))
 }
 
+//go:linkname C.__CBytes runtime.cgo_CBytes
+func C.__CBytes([]byte) unsafe.Pointer
+
+func C.CBytes(b []byte) unsafe.Pointer {
+	return C.__CBytes(b)
+}
+
 type (
 	C.char      uint8
 	C.schar     int8

compileopts/config.go

@@ -33,6 +33,17 @@ func (c *Config) CPU() string {
 	return c.Target.CPU
 }
 
+// The current build mode (like the `-buildmode` command line flag).
+func (c *Config) BuildMode() string {
+	if c.Options.BuildMode != "" {
+		return c.Options.BuildMode
+	}
+	if c.Target.BuildMode != "" {
+		return c.Target.BuildMode
+	}
+	return "default"
+}
+
 // Features returns a list of features this CPU supports. For example, for a
 // RISC-V processor, that could be "+a,+c,+m". For many targets, an empty list
 // will be returned.
@@ -395,6 +406,16 @@ func (c *Config) LDFlags() []string {
 	if c.Target.LinkerScript != "" {
 		ldflags = append(ldflags, "-T", c.Target.LinkerScript)
 	}
+
+	if c.Options.ExtLDFlags != "" {
+		ext, err := shlex.Split(c.Options.ExtLDFlags)
+		if err != nil {
+			// if shlex can't split it, pass it as-is and let the external linker complain
+			ext = []string{c.Options.ExtLDFlags}
+		}
+		ldflags = append(ldflags, ext...)
+	}
+
 	return ldflags
 }
 

compileopts/options.go

@@ -8,6 +8,7 @@ import (
 )
 
 var (
+	validBuildModeOptions     = []string{"default", "c-shared"}
 	validGCOptions            = []string{"none", "leaking", "conservative", "custom", "precise"}
 	validSchedulerOptions     = []string{"none", "tasks", "asyncify"}
 	validSerialOptions        = []string{"none", "uart", "usb", "rtt"}
@@ -26,6 +27,7 @@ type Options struct {
 	GOMIPS          string // environment variable (only used with GOARCH=mips and GOARCH=mipsle)
 	Directory       string // working dir, leave it unset to use the current working dir
 	Target          string
+	BuildMode       string // -buildmode flag
 	Opt             string
 	GC              string
 	PanicStrategy   string
@@ -56,10 +58,19 @@ type Options struct {
 	Timeout         time.Duration
 	WITPackage      string // pass through to wasm-tools component embed invocation
 	WITWorld        string // pass through to wasm-tools component embed -w option
+	ExtLDFlags      string
 }
 
 // Verify performs a validation on the given options, raising an error if options are not valid.
 func (o *Options) Verify() error {
+	if o.BuildMode != "" {
+		valid := isInArray(validBuildModeOptions, o.BuildMode)
+		if !valid {
+			return fmt.Errorf(`invalid buildmode option '%s': valid values are %s`,
+				o.BuildMode,
+				strings.Join(validBuildModeOptions, ", "))
+		}
+	}
 	if o.GC != "" {
 		valid := isInArray(validGCOptions, o.GC)
 		if !valid {

compileopts/target.go

@@ -32,6 +32,7 @@ type TargetSpec struct {
 	GOARCH           string   `json:"goarch,omitempty"`
 	SoftFloat        bool     // used for non-baremetal systems (GOMIPS=softfloat etc)
 	BuildTags        []string `json:"build-tags,omitempty"`
+	BuildMode        string   `json:"buildmode,omitempty"` // default build mode (if nothing specified)
 	GC               string   `json:"gc,omitempty"`
 	Scheduler        string   `json:"scheduler,omitempty"`
 	Serial           string   `json:"serial,omitempty"` // which serial output to use (uart, usb, none)
@@ -336,7 +337,7 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 			spec.Features = "+fp-armv8,+neon,-fmv,-outline-atomics"
 		}
 	case "mips", "mipsle":
-		spec.CPU = "mips32r2"
+		spec.CPU = "mips32"
 		spec.CFlags = append(spec.CFlags, "-fno-pic")
 		if options.GOARCH == "mips" {
 			llvmarch = "mips" // big endian
@@ -345,10 +346,10 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 		}
 		switch options.GOMIPS {
 		case "hardfloat":
-			spec.Features = "+fpxx,+mips32r2,+nooddspreg,-noabicalls"
+			spec.Features = "+fpxx,+mips32,+nooddspreg,-noabicalls"
 		case "softfloat":
 			spec.SoftFloat = true
-			spec.Features = "+mips32r2,+soft-float,-noabicalls"
+			spec.Features = "+mips32,+soft-float,-noabicalls"
 			spec.CFlags = append(spec.CFlags, "-msoft-float")
 		default:
 			return nil, fmt.Errorf("invalid GOMIPS=%s: must be hardfloat or softfloat", options.GOMIPS)
@@ -389,7 +390,9 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 			"-platform_version", "macos", platformVersion, platformVersion,
 		)
 		spec.ExtraFiles = append(spec.ExtraFiles,
-			"src/runtime/runtime_unix.c")
+			"src/runtime/os_darwin.c",
+			"src/runtime/runtime_unix.c",
+			"src/runtime/signal.c")
 	case "linux":
 		spec.Linker = "ld.lld"
 		spec.RTLib = "compiler-rt"
@@ -410,7 +413,8 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 			spec.CFlags = append(spec.CFlags, "-mno-outline-atomics")
 		}
 		spec.ExtraFiles = append(spec.ExtraFiles,
-			"src/runtime/runtime_unix.c")
+			"src/runtime/runtime_unix.c",
+			"src/runtime/signal.c")
 	case "windows":
 		spec.Linker = "ld.lld"
 		spec.Libc = "mingw-w64"
@@ -448,7 +452,7 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 			"--stack-first",
 			"--no-demangle",
 		)
-		spec.Emulator = "wasmtime --dir={tmpDir}::/tmp {}"
+		spec.Emulator = "wasmtime run --dir={tmpDir}::/tmp {}"
 		spec.ExtraFiles = append(spec.ExtraFiles,
 			"src/runtime/asm_tinygowasm.S",
 			"src/internal/task/task_asyncify_wasm.S",

compiler/compiler.go

@@ -44,6 +44,7 @@ type Config struct {
 	ABI             string
 	GOOS            string
 	GOARCH          string
+	BuildMode       string
 	CodeModel       string
 	RelocationModel string
 	SizeLevel       int
@@ -1384,6 +1385,11 @@ func (b *builder) createFunction() {
 		b.llvmFn.SetLinkage(llvm.InternalLinkage)
 		b.createFunction()
 	}
+
+	// Create wrapper function that can be called externally.
+	if b.info.wasmExport != "" {
+		b.createWasmExport()
+	}
 }
 
 // posser is an interface that's implemented by both ssa.Value and
@@ -1847,7 +1853,9 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 		case strings.HasPrefix(name, "(device/riscv.CSR)."):
 			return b.emitCSROperation(instr)
 		case strings.HasPrefix(name, "syscall.Syscall") || strings.HasPrefix(name, "syscall.RawSyscall") || strings.HasPrefix(name, "golang.org/x/sys/unix.Syscall") || strings.HasPrefix(name, "golang.org/x/sys/unix.RawSyscall"):
-			return b.createSyscall(instr)
+			if b.GOOS != "darwin" {
+				return b.createSyscall(instr)
+			}
 		case strings.HasPrefix(name, "syscall.rawSyscallNoError") || strings.HasPrefix(name, "golang.org/x/sys/unix.RawSyscallNoError"):
 			return b.createRawSyscallNoError(instr)
 		case name == "runtime.supportsRecover":
@@ -1865,6 +1873,11 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 			return llvm.ConstInt(b.ctx.Int8Type(), panicStrategy, false), nil
 		case name == "runtime/interrupt.New":
 			return b.createInterruptGlobal(instr)
+		case name == "internal/abi.FuncPCABI0":
+			retval := b.createDarwinFuncPCABI0Call(instr)
+			if !retval.IsNil() {
+				return retval, nil
+			}
 		}
 
 		calleeType, callee = b.getFunction(fn)

compiler/goroutine.go

@@ -7,43 +7,14 @@ import (
 	"go/token"
 	"go/types"
 
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
 
 // createGo emits code to start a new goroutine.
 func (b *builder) createGo(instr *ssa.Go) {
-	// Get all function parameters to pass to the goroutine.
-	var params []llvm.Value
-	for _, param := range instr.Call.Args {
-		params = append(params, b.getValue(param, getPos(instr)))
-	}
-
-	var prefix string
-	var funcPtr llvm.Value
-	var funcType llvm.Type
-	hasContext := false
-	if callee := instr.Call.StaticCallee(); callee != nil {
-		// Static callee is known. This makes it easier to start a new
-		// goroutine.
-		var context llvm.Value
-		switch value := instr.Call.Value.(type) {
-		case *ssa.Function:
-			// Goroutine call is regular function call. No context is necessary.
-		case *ssa.MakeClosure:
-			// A goroutine call on a func value, but the callee is trivial to find. For
-			// example: immediately applied functions.
-			funcValue := b.getValue(value, getPos(instr))
-			context = b.extractFuncContext(funcValue)
-		default:
-			panic("StaticCallee returned an unexpected value")
-		}
-		if !context.IsNil() {
-			params = append(params, context) // context parameter
-			hasContext = true
-		}
-		funcType, funcPtr = b.getFunction(callee)
-	} else if builtin, ok := instr.Call.Value.(*ssa.Builtin); ok {
+	if builtin, ok := instr.Call.Value.(*ssa.Builtin); ok {
 		// We cheat. None of the builtins do any long or blocking operation, so
 		// we might as well run these builtins right away without the program
 		// noticing the difference.
@@ -74,6 +45,38 @@ func (b *builder) createGo(instr *ssa.Go) {
 		}
 		b.createBuiltin(argTypes, argValues, builtin.Name(), instr.Pos())
 		return
+	}
+
+	// Get all function parameters to pass to the goroutine.
+	var params []llvm.Value
+	for _, param := range instr.Call.Args {
+		params = append(params, b.expandFormalParam(b.getValue(param, getPos(instr)))...)
+	}
+
+	var prefix string
+	var funcPtr llvm.Value
+	var funcType llvm.Type
+	hasContext := false
+	if callee := instr.Call.StaticCallee(); callee != nil {
+		// Static callee is known. This makes it easier to start a new
+		// goroutine.
+		var context llvm.Value
+		switch value := instr.Call.Value.(type) {
+		case *ssa.Function:
+			// Goroutine call is regular function call. No context is necessary.
+		case *ssa.MakeClosure:
+			// A goroutine call on a func value, but the callee is trivial to find. For
+			// example: immediately applied functions.
+			funcValue := b.getValue(value, getPos(instr))
+			context = b.extractFuncContext(funcValue)
+		default:
+			panic("StaticCallee returned an unexpected value")
+		}
+		if !context.IsNil() {
+			params = append(params, context) // context parameter
+			hasContext = true
+		}
+		funcType, funcPtr = b.getFunction(callee)
 	} else if instr.Call.IsInvoke() {
 		// This is a method call on an interface value.
 		itf := b.getValue(instr.Call.Value, getPos(instr))
@@ -99,7 +102,7 @@ func (b *builder) createGo(instr *ssa.Go) {
 
 	paramBundle := b.emitPointerPack(params)
 	var stackSize llvm.Value
-	callee := b.createGoroutineStartWrapper(funcType, funcPtr, prefix, hasContext, instr.Pos())
+	callee := b.createGoroutineStartWrapper(funcType, funcPtr, prefix, hasContext, false, instr.Pos())
 	if b.AutomaticStackSize {
 		// The stack size is not known until after linking. Call a dummy
 		// function that will be replaced with a load from a special ELF
@@ -119,6 +122,147 @@ func (b *builder) createGo(instr *ssa.Go) {
 	b.createCall(fnType, start, []llvm.Value{callee, paramBundle, stackSize, llvm.Undef(b.dataPtrType)}, "")
 }
 
+// Create an exported wrapper function for functions with the //go:wasmexport
+// pragma. This wrapper function is quite complex when the scheduler is enabled:
+// it needs to start a new goroutine each time the exported function is called.
+func (b *builder) createWasmExport() {
+	pos := b.info.wasmExportPos
+	if b.info.exported {
+		// //export really shouldn't be used anymore when //go:wasmexport is
+		// available, because //go:wasmexport is much better defined.
+		b.addError(pos, "cannot use //export and //go:wasmexport at the same time")
+		return
+	}
+
+	const suffix = "#wasmexport"
+
+	// Declare the exported function.
+	paramTypes := b.llvmFnType.ParamTypes()
+	exportedFnType := llvm.FunctionType(b.llvmFnType.ReturnType(), paramTypes[:len(paramTypes)-1], false)
+	exportedFn := llvm.AddFunction(b.mod, b.fn.RelString(nil)+suffix, exportedFnType)
+	b.addStandardAttributes(exportedFn)
+	llvmutil.AppendToGlobal(b.mod, "llvm.used", exportedFn)
+	exportedFn.AddFunctionAttr(b.ctx.CreateStringAttribute("wasm-export-name", b.info.wasmExport))
+
+	// Create a builder for this wrapper function.
+	builder := newBuilder(b.compilerContext, b.ctx.NewBuilder(), b.fn)
+	defer builder.Dispose()
+
+	// Define this function as a separate function in DWARF
+	if b.Debug {
+		if b.fn.Syntax() != nil {
+			// Create debug info file if needed.
+			pos := b.program.Fset.Position(pos)
+			builder.difunc = builder.attachDebugInfoRaw(b.fn, exportedFn, suffix, pos.Filename, pos.Line)
+		}
+		builder.setDebugLocation(pos)
+	}
+
+	// Create a single basic block inside of it.
+	bb := llvm.AddBasicBlock(exportedFn, "entry")
+	builder.SetInsertPointAtEnd(bb)
+
+	// Insert an assertion to make sure this //go:wasmexport function is not
+	// called at a time when it is not allowed (for example, before the runtime
+	// is initialized).
+	builder.createRuntimeCall("wasmExportCheckRun", nil, "")
+
+	if b.Scheduler == "none" {
+		// When the scheduler has been disabled, this is really trivial: just
+		// call the function.
+		params := exportedFn.Params()
+		params = append(params, llvm.ConstNull(b.dataPtrType)) // context parameter
+		retval := builder.CreateCall(b.llvmFnType, b.llvmFn, params, "")
+		if b.fn.Signature.Results() == nil {
+			builder.CreateRetVoid()
+		} else {
+			builder.CreateRet(retval)
+		}
+
+	} else {
+		// The scheduler is enabled, so we need to start a new goroutine, wait
+		// for it to complete, and read the result value.
+
+		// Build a function that looks like this:
+		//
+		//   func foo#wasmexport(param0, param1, ..., paramN) {
+		//       var state *stateStruct
+		//
+		//       // 'done' must be explicitly initialized ('state' is not zeroed)
+		//       state.done = false
+		//
+		//       // store the parameters in the state object
+		//       state.param0 = param0
+		//       state.param1 = param1
+		//       ...
+		//       state.paramN = paramN
+		//
+		//       // create a goroutine and push it to the runqueue
+		//       task.start(uintptr(gowrapper), &state)
+		//
+		//       // run the scheduler
+		//       runtime.wasmExportRun(&state.done)
+		//
+		//       // if there is a return value, load it and return
+		//       return state.result
+		//   }
+
+		hasReturn := b.fn.Signature.Results() != nil
+
+		// Build the state struct type.
+		// It stores the function parameters, the 'done' flag, and reserves
+		// space for a return value if needed.
+		stateFields := exportedFnType.ParamTypes()
+		numParams := len(stateFields)
+		stateFields = append(stateFields, b.ctx.Int1Type()) // 'done' field
+		if hasReturn {
+			stateFields = append(stateFields, b.llvmFnType.ReturnType())
+		}
+		stateStruct := b.ctx.StructType(stateFields, false)
+
+		// Allocate the state struct on the stack.
+		statePtr := builder.CreateAlloca(stateStruct, "status")
+
+		// Initialize the 'done' field.
+		doneGEP := builder.CreateInBoundsGEP(stateStruct, statePtr, []llvm.Value{
+			llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(b.ctx.Int32Type(), uint64(numParams), false),
+		}, "done.gep")
+		builder.CreateStore(llvm.ConstNull(b.ctx.Int1Type()), doneGEP)
+
+		// Store all parameters in the state object.
+		for i, param := range exportedFn.Params() {
+			gep := builder.CreateInBoundsGEP(stateStruct, statePtr, []llvm.Value{
+				llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+				llvm.ConstInt(b.ctx.Int32Type(), uint64(i), false),
+			}, "")
+			builder.CreateStore(param, gep)
+		}
+
+		// Create a new goroutine and add it to the runqueue.
+		wrapper := b.createGoroutineStartWrapper(b.llvmFnType, b.llvmFn, "", false, true, pos)
+		stackSize := llvm.ConstInt(b.uintptrType, b.DefaultStackSize, false)
+		taskStartFnType, taskStartFn := builder.getFunction(b.program.ImportedPackage("internal/task").Members["start"].(*ssa.Function))
+		builder.createCall(taskStartFnType, taskStartFn, []llvm.Value{wrapper, statePtr, stackSize, llvm.Undef(b.dataPtrType)}, "")
+
+		// Run the scheduler.
+		builder.createRuntimeCall("wasmExportRun", []llvm.Value{doneGEP}, "")
+
+		// Read the return value (if any) and return to the caller of the
+		// //go:wasmexport function.
+		if hasReturn {
+			gep := builder.CreateInBoundsGEP(stateStruct, statePtr, []llvm.Value{
+				llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+				llvm.ConstInt(b.ctx.Int32Type(), uint64(numParams)+1, false),
+			}, "")
+			retval := builder.CreateLoad(b.llvmFnType.ReturnType(), gep, "retval")
+			builder.CreateRet(retval)
+		} else {
+			builder.CreateRetVoid()
+		}
+	}
+}
+
 // createGoroutineStartWrapper creates a wrapper for the task-based
 // implementation of goroutines. For example, to call a function like this:
 //
@@ -142,7 +286,7 @@ func (b *builder) createGo(instr *ssa.Go) {
 // to last parameter of the function) is used for this wrapper. If hasContext is
 // false, the parameter bundle is assumed to have no context parameter and undef
 // is passed instead.
-func (c *compilerContext) createGoroutineStartWrapper(fnType llvm.Type, fn llvm.Value, prefix string, hasContext bool, pos token.Pos) llvm.Value {
+func (c *compilerContext) createGoroutineStartWrapper(fnType llvm.Type, fn llvm.Value, prefix string, hasContext, isWasmExport bool, pos token.Pos) llvm.Value {
 	var wrapper llvm.Value
 
 	b := &builder{
@@ -160,14 +304,18 @@ func (c *compilerContext) createGoroutineStartWrapper(fnType llvm.Type, fn llvm.
 	if !fn.IsAFunction().IsNil() {
 		// See whether this wrapper has already been created. If so, return it.
 		name := fn.Name()
-		wrapper = c.mod.NamedFunction(name + "$gowrapper")
+		wrapperName := name + "$gowrapper"
+		if isWasmExport {
+			wrapperName += "-wasmexport"
+		}
+		wrapper = c.mod.NamedFunction(wrapperName)
 		if !wrapper.IsNil() {
 			return llvm.ConstPtrToInt(wrapper, c.uintptrType)
 		}
 
 		// Create the wrapper.
 		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.dataPtrType}, false)
-		wrapper = llvm.AddFunction(c.mod, name+"$gowrapper", wrapperType)
+		wrapper = llvm.AddFunction(c.mod, wrapperName, wrapperType)
 		c.addStandardAttributes(wrapper)
 		wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
 		wrapper.SetUnnamedAddr(true)
@@ -197,23 +345,110 @@ func (c *compilerContext) createGoroutineStartWrapper(fnType llvm.Type, fn llvm.
 			b.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
 		}
 
-		// Create the list of params for the call.
-		paramTypes := fnType.ParamTypes()
-		if !hasContext {
-			paramTypes = paramTypes[:len(paramTypes)-1] // strip context parameter
-		}
-		params := b.emitPointerUnpack(wrapper.Param(0), paramTypes)
-		if !hasContext {
-			params = append(params, llvm.Undef(c.dataPtrType)) // add dummy context parameter
-		}
+		if !isWasmExport {
+			// Regular 'go' instruction.
 
-		// Create the call.
-		b.CreateCall(fnType, fn, params, "")
+			// Create the list of params for the call.
+			paramTypes := fnType.ParamTypes()
+			if !hasContext {
+				paramTypes = paramTypes[:len(paramTypes)-1] // strip context parameter
+			}
 
-		if c.Scheduler == "asyncify" {
-			b.CreateCall(deadlockType, deadlock, []llvm.Value{
-				llvm.Undef(c.dataPtrType),
-			}, "")
+			params := b.emitPointerUnpack(wrapper.Param(0), paramTypes)
+			if !hasContext {
+				params = append(params, llvm.Undef(c.dataPtrType)) // add dummy context parameter
+			}
+
+			// Create the call.
+			b.CreateCall(fnType, fn, params, "")
+
+			if c.Scheduler == "asyncify" {
+				b.CreateCall(deadlockType, deadlock, []llvm.Value{
+					llvm.Undef(c.dataPtrType),
+				}, "")
+			}
+		} else {
+			// Goroutine started from a //go:wasmexport pragma.
+			// The function looks like this:
+			//
+			//   func foo$gowrapper-wasmexport(state *stateStruct) {
+			//       // load values
+			//       param0 := state.params[0]
+			//       param1 := state.params[1]
+			//
+			//       // call wrapped functions
+			//       result := foo(param0, param1, ...)
+			//
+			//       // store result value (if there is any)
+			//       state.result = result
+			//
+			//       // finish exported function
+			//       state.done = true
+			//       runtime.wasmExportExit()
+			//   }
+			//
+			// The state object here looks like:
+			//
+			//   struct state {
+			//       param0
+			//       param1
+			//       param* // etc
+			//       done bool
+			//       result returnType
+			//   }
+
+			returnType := fnType.ReturnType()
+			hasReturn := returnType != b.ctx.VoidType()
+			statePtr := wrapper.Param(0)
+
+			// Create the state struct (it must match the type in createWasmExport).
+			stateFields := fnType.ParamTypes()
+			numParams := len(stateFields) - 1
+			stateFields = stateFields[:numParams:numParams]     // strip 'context' parameter
+			stateFields = append(stateFields, c.ctx.Int1Type()) // 'done' bool
+			if hasReturn {
+				stateFields = append(stateFields, returnType)
+			}
+			stateStruct := b.ctx.StructType(stateFields, false)
+
+			// Extract parameters from the state object, and call the function
+			// that's being wrapped.
+			var callParams []llvm.Value
+			for i := 0; i < numParams; i++ {
+				gep := b.CreateInBoundsGEP(stateStruct, statePtr, []llvm.Value{
+					llvm.ConstInt(b.ctx.Int32Type(), 0, false),
+					llvm.ConstInt(b.ctx.Int32Type(), uint64(i), false),
+				}, "")
+				param := b.CreateLoad(stateFields[i], gep, "")
+				callParams = append(callParams, param)
+			}
+			callParams = append(callParams, llvm.ConstNull(c.dataPtrType)) // add 'context' parameter
+			result := b.CreateCall(fnType, fn, callParams, "")
+
+			// Store the return value back into the shared state.
+			// Unlike regular goroutines, these special //go:wasmexport
+			// goroutines can return a value.
+			if hasReturn {
+				gep := b.CreateInBoundsGEP(stateStruct, statePtr, []llvm.Value{
+					llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+					llvm.ConstInt(c.ctx.Int32Type(), uint64(numParams)+1, false),
+				}, "result.ptr")
+				b.CreateStore(result, gep)
+			}
+
+			// Mark this function as having finished executing.
+			// This is important so the runtime knows the exported function
+			// didn't block.
+			doneGEP := b.CreateInBoundsGEP(stateStruct, statePtr, []llvm.Value{
+				llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+				llvm.ConstInt(c.ctx.Int32Type(), uint64(numParams), false),
+			}, "done.gep")
+			b.CreateStore(llvm.ConstInt(b.ctx.Int1Type(), 1, false), doneGEP)
+
+			// Call back into the runtime. This will exit the goroutine, switch
+			// back to the scheduler, which will in turn return from the
+			// //go:wasmexport function.
+			b.createRuntimeCall("wasmExportExit", nil, "")
 		}
 
 	} else {
@@ -295,5 +530,5 @@ func (c *compilerContext) createGoroutineStartWrapper(fnType llvm.Type, fn llvm.
 	}
 
 	// Return a ptrtoint of the wrapper, not the function itself.
-	return b.CreatePtrToInt(wrapper, c.uintptrType, "")
+	return llvm.ConstPtrToInt(wrapper, c.uintptrType)
 }

compiler/llvmutil/llvm.go

@@ -8,6 +8,7 @@
 package llvmutil
 
 import (
+	"encoding/binary"
 	"strconv"
 	"strings"
 
@@ -216,3 +217,13 @@ func Version() int {
 	}
 	return major
 }
+
+// Return the byte order for the given target triple. Most targets are little
+// endian, but for example MIPS can be big-endian.
+func ByteOrder(target string) binary.ByteOrder {
+	if strings.HasPrefix(target, "mips-") {
+		return binary.BigEndian
+	} else {
+		return binary.LittleEndian
+	}
+}

compiler/symbol.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 
 	"github.com/tinygo-org/tinygo/compiler/llvmutil"
+	"github.com/tinygo-org/tinygo/goenv"
 	"github.com/tinygo-org/tinygo/loader"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
@@ -23,15 +24,17 @@ import (
 // The linkName value contains a valid link name, even if //go:linkname is not
 // present.
 type functionInfo struct {
-	wasmModule string     // go:wasm-module
-	wasmName   string     // wasm-export-name or wasm-import-name in the IR
-	linkName   string     // go:linkname, go:export - the IR function name
-	section    string     // go:section - object file section name
-	exported   bool       // go:export, CGo
-	interrupt  bool       // go:interrupt
-	nobounds   bool       // go:nobounds
-	variadic   bool       // go:variadic (CGo only)
-	inline     inlineType // go:inline
+	wasmModule    string     // go:wasm-module
+	wasmName      string     // wasm-export-name or wasm-import-name in the IR
+	wasmExport    string     // go:wasmexport is defined (export is unset, this adds an exported wrapper)
+	wasmExportPos token.Pos  // position of //go:wasmexport comment
+	linkName      string     // go:linkname, go:export - the IR function name
+	section       string     // go:section - object file section name
+	exported      bool       // go:export, CGo
+	interrupt     bool       // go:interrupt
+	nobounds      bool       // go:nobounds
+	variadic      bool       // go:variadic (CGo only)
+	inline        inlineType // go:inline
 }
 
 type inlineType int
@@ -170,6 +173,12 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
 		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
+	case "runtime.stringFromBytes":
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
+	case "runtime.stringFromRunes":
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
 	case "runtime.trackPointer":
 		// This function is necessary for tracking pointers on the stack in a
 		// portable way (see gc_stack_portable.go). Indicate to the optimizer
@@ -241,8 +250,22 @@ func (c *compilerContext) getFunctionInfo(f *ssa.Function) functionInfo {
 		// Pick the default linkName.
 		linkName: f.RelString(nil),
 	}
+
+	// Check for a few runtime functions that are treated specially.
+	if info.linkName == "runtime.wasmEntryReactor" && c.BuildMode == "c-shared" {
+		info.linkName = "_initialize"
+		info.wasmName = "_initialize"
+		info.exported = true
+	}
+	if info.linkName == "runtime.wasmEntryCommand" && c.BuildMode == "default" {
+		info.linkName = "_start"
+		info.wasmName = "_start"
+		info.exported = true
+	}
+
 	// Check for //go: pragmas, which may change the link name (among others).
 	c.parsePragmas(&info, f)
+
 	c.functionInfos[f] = info
 	return info
 }
@@ -250,126 +273,164 @@ func (c *compilerContext) getFunctionInfo(f *ssa.Function) functionInfo {
 // parsePragmas is used by getFunctionInfo to parse function pragmas such as
 // //export or //go:noinline.
 func (c *compilerContext) parsePragmas(info *functionInfo, f *ssa.Function) {
-	if f.Syntax() == nil {
+	syntax := f.Syntax()
+	if f.Origin() != nil {
+		syntax = f.Origin().Syntax()
+	}
+	if syntax == nil {
 		return
 	}
-	if decl, ok := f.Syntax().(*ast.FuncDecl); ok && decl.Doc != nil {
+
+	// Read all pragmas of this function.
+	var pragmas []*ast.Comment
+	hasWasmExport := false
+	if decl, ok := syntax.(*ast.FuncDecl); ok && decl.Doc != nil {
 		for _, comment := range decl.Doc.List {
 			text := comment.Text
-			if strings.HasPrefix(text, "//export ") {
-				// Rewrite '//export' to '//go:export' for compatibility with
-				// gc.
-				text = "//go:" + text[2:]
+			if strings.HasPrefix(text, "//go:") || strings.HasPrefix(text, "//export ") {
+				pragmas = append(pragmas, comment)
+				if strings.HasPrefix(comment.Text, "//go:wasmexport ") {
+					hasWasmExport = true
+				}
 			}
-			if !strings.HasPrefix(text, "//go:") {
+		}
+	}
+
+	// Parse each pragma.
+	for _, comment := range pragmas {
+		parts := strings.Fields(comment.Text)
+		switch parts[0] {
+		case "//export", "//go:export":
+			if len(parts) != 2 {
+				continue
+			}
+			if hasWasmExport {
+				// //go:wasmexport overrides //export.
 				continue
 			}
-			parts := strings.Fields(text)
-			switch parts[0] {
-			case "//go:export":
-				if len(parts) != 2 {
-					continue
-				}
 
-				info.linkName = parts[1]
-				info.wasmName = info.linkName
-				info.exported = true
-			case "//go:interrupt":
-				if hasUnsafeImport(f.Pkg.Pkg) {
-					info.interrupt = true
-				}
-			case "//go:wasm-module":
-				// Alternative comment for setting the import module.
-				// This is deprecated, use //go:wasmimport instead.
-				if len(parts) != 2 {
-					continue
-				}
-				info.wasmModule = parts[1]
-			case "//go:wasmimport":
-				// Import a WebAssembly function, for example a WASI function.
-				// Original proposal: https://github.com/golang/go/issues/38248
-				// Allow globally: https://github.com/golang/go/issues/59149
-				if len(parts) != 3 {
-					continue
-				}
-				c.checkWasmImport(f, comment.Text)
-				info.exported = true
-				info.wasmModule = parts[1]
-				info.wasmName = parts[2]
-			case "//go:inline":
-				info.inline = inlineHint
-			case "//go:noinline":
+			info.linkName = parts[1]
+			info.wasmName = info.linkName
+			info.exported = true
+		case "//go:interrupt":
+			if hasUnsafeImport(f.Pkg.Pkg) {
+				info.interrupt = true
+			}
+		case "//go:wasm-module":
+			// Alternative comment for setting the import module.
+			// This is deprecated, use //go:wasmimport instead.
+			if len(parts) != 2 {
+				continue
+			}
+			info.wasmModule = parts[1]
+		case "//go:wasmimport":
+			// Import a WebAssembly function, for example a WASI function.
+			// Original proposal: https://github.com/golang/go/issues/38248
+			// Allow globally: https://github.com/golang/go/issues/59149
+			if len(parts) != 3 {
+				continue
+			}
+			if f.Blocks != nil {
+				// Defined functions cannot be exported.
+				c.addError(f.Pos(), "can only use //go:wasmimport on declarations")
+				continue
+			}
+			c.checkWasmImportExport(f, comment.Text)
+			info.exported = true
+			info.wasmModule = parts[1]
+			info.wasmName = parts[2]
+		case "//go:wasmexport":
+			if f.Blocks == nil {
+				c.addError(f.Pos(), "can only use //go:wasmexport on definitions")
+				continue
+			}
+			if len(parts) != 2 {
+				c.addError(f.Pos(), fmt.Sprintf("expected one parameter to //go:wasmimport, not %d", len(parts)-1))
+				continue
+			}
+			name := parts[1]
+			if name == "_start" || name == "_initialize" {
+				c.addError(f.Pos(), fmt.Sprintf("//go:wasmexport does not allow %#v", name))
+				continue
+			}
+			if c.BuildMode != "c-shared" && f.RelString(nil) == "main.main" {
+				c.addError(f.Pos(), fmt.Sprintf("//go:wasmexport does not allow main.main to be exported with -buildmode=%s", c.BuildMode))
+				continue
+			}
+			if c.archFamily() != "wasm32" {
+				c.addError(f.Pos(), "//go:wasmexport is only supported on wasm")
+			}
+			c.checkWasmImportExport(f, comment.Text)
+			info.wasmExport = name
+			info.wasmExportPos = comment.Slash
+		case "//go:inline":
+			info.inline = inlineHint
+		case "//go:noinline":
+			info.inline = inlineNone
+		case "//go:linkname":
+			if len(parts) != 3 || parts[1] != f.Name() {
+				continue
+			}
+			// Only enable go:linkname when the package imports "unsafe".
+			// This is a slightly looser requirement than what gc uses: gc
+			// requires the file to import "unsafe", not the package as a
+			// whole.
+			if hasUnsafeImport(f.Pkg.Pkg) {
+				info.linkName = parts[2]
+			}
+		case "//go:section":
+			// Only enable go:section when the package imports "unsafe".
+			// go:section also implies go:noinline since inlining could
+			// move the code to a different section than that requested.
+			if len(parts) == 2 && hasUnsafeImport(f.Pkg.Pkg) {
+				info.section = parts[1]
 				info.inline = inlineNone
-			case "//go:linkname":
-				if len(parts) != 3 || parts[1] != f.Name() {
-					continue
-				}
-				// Only enable go:linkname when the package imports "unsafe".
-				// This is a slightly looser requirement than what gc uses: gc
-				// requires the file to import "unsafe", not the package as a
-				// whole.
-				if hasUnsafeImport(f.Pkg.Pkg) {
-					info.linkName = parts[2]
-				}
-			case "//go:section":
-				// Only enable go:section when the package imports "unsafe".
-				// go:section also implies go:noinline since inlining could
-				// move the code to a different section than that requested.
-				if len(parts) == 2 && hasUnsafeImport(f.Pkg.Pkg) {
-					info.section = parts[1]
-					info.inline = inlineNone
-				}
-			case "//go:nobounds":
-				// Skip bounds checking in this function. Useful for some
-				// runtime functions.
-				// This is somewhat dangerous and thus only imported in packages
-				// that import unsafe.
-				if hasUnsafeImport(f.Pkg.Pkg) {
-					info.nobounds = true
-				}
-			case "//go:variadic":
-				// The //go:variadic pragma is emitted by the CGo preprocessing
-				// pass for C variadic functions. This includes both explicit
-				// (with ...) and implicit (no parameters in signature)
-				// functions.
-				if strings.HasPrefix(f.Name(), "C.") {
-					// This prefix cannot naturally be created, it must have
-					// been created as a result of CGo preprocessing.
-					info.variadic = true
-				}
+			}
+		case "//go:nobounds":
+			// Skip bounds checking in this function. Useful for some
+			// runtime functions.
+			// This is somewhat dangerous and thus only imported in packages
+			// that import unsafe.
+			if hasUnsafeImport(f.Pkg.Pkg) {
+				info.nobounds = true
+			}
+		case "//go:variadic":
+			// The //go:variadic pragma is emitted by the CGo preprocessing
+			// pass for C variadic functions. This includes both explicit
+			// (with ...) and implicit (no parameters in signature)
+			// functions.
+			if strings.HasPrefix(f.Name(), "C.") {
+				// This prefix cannot naturally be created, it must have
+				// been created as a result of CGo preprocessing.
+				info.variadic = true
 			}
 		}
 	}
 }
 
-// Check whether this function cannot be used in //go:wasmimport. It will add an
-// error if this is the case.
+// Check whether this function can be used in //go:wasmimport or
+// //go:wasmexport. It will add an error if this is not the case.
 //
 // The list of allowed types is based on this proposal:
 // https://github.com/golang/go/issues/59149
-func (c *compilerContext) checkWasmImport(f *ssa.Function, pragma string) {
+func (c *compilerContext) checkWasmImportExport(f *ssa.Function, pragma string) {
 	if c.pkg.Path() == "runtime" || c.pkg.Path() == "syscall/js" || c.pkg.Path() == "syscall" {
 		// The runtime is a special case. Allow all kinds of parameters
 		// (importantly, including pointers).
 		return
 	}
-	if f.Blocks != nil {
-		// Defined functions cannot be exported.
-		c.addError(f.Pos(), "can only use //go:wasmimport on declarations")
-		return
-	}
 	if f.Signature.Results().Len() > 1 {
 		c.addError(f.Signature.Results().At(1).Pos(), fmt.Sprintf("%s: too many return values", pragma))
 	} else if f.Signature.Results().Len() == 1 {
 		result := f.Signature.Results().At(0)
-		if !isValidWasmType(result.Type(), siteResult) {
+		if !c.isValidWasmType(result.Type(), siteResult) {
 			c.addError(result.Pos(), fmt.Sprintf("%s: unsupported result type %s", pragma, result.Type().String()))
 		}
 	}
 	for _, param := range f.Params {
 		// Check whether the type is allowed.
 		// Only a very limited number of types can be mapped to WebAssembly.
-		if !isValidWasmType(param.Type(), siteParam) {
+		if !c.isValidWasmType(param.Type(), siteParam) {
 			c.addError(param.Pos(), fmt.Sprintf("%s: unsupported parameter type %s", pragma, param.Type().String()))
 		}
 	}
@@ -382,13 +443,15 @@ func (c *compilerContext) checkWasmImport(f *ssa.Function, pragma string) {
 //
 // This previously reflected the additional restrictions documented here:
 // https://github.com/golang/go/issues/59149
-func isValidWasmType(typ types.Type, site wasmSite) bool {
+func (c *compilerContext) isValidWasmType(typ types.Type, site wasmSite) bool {
 	switch typ := typ.Underlying().(type) {
 	case *types.Basic:
 		switch typ.Kind() {
 		case types.Bool:
 			return true
-		case types.Int, types.Uint, types.Int8, types.Uint8, types.Int16, types.Uint16, types.Int32, types.Uint32, types.Int64, types.Uint64:
+		case types.Int8, types.Uint8, types.Int16, types.Uint16:
+			return site == siteIndirect
+		case types.Int32, types.Uint32, types.Int64, types.Uint64:
 			return true
 		case types.Float32, types.Float64:
 			return true
@@ -399,19 +462,35 @@ func isValidWasmType(typ types.Type, site wasmSite) bool {
 			return site == siteParam || site == siteIndirect
 		}
 	case *types.Array:
-		return site == siteIndirect && isValidWasmType(typ.Elem(), siteIndirect)
+		return site == siteIndirect && c.isValidWasmType(typ.Elem(), siteIndirect)
 	case *types.Struct:
 		if site != siteIndirect {
 			return false
 		}
+		// Structs with no fields do not need structs.HostLayout
+		if typ.NumFields() == 0 {
+			return true
+		}
+		hasHostLayout := true // default to true before detecting Go version
+		// (*types.Package).GoVersion added in go1.21
+		if gv, ok := any(c.pkg).(interface{ GoVersion() string }); ok {
+			if goenv.Compare(gv.GoVersion(), "go1.23") >= 0 {
+				hasHostLayout = false // package structs added in go1.23
+			}
+		}
 		for i := 0; i < typ.NumFields(); i++ {
-			if !isValidWasmType(typ.Field(i).Type(), siteIndirect) {
+			ftyp := typ.Field(i).Type()
+			if ftyp.String() == "structs.HostLayout" {
+				hasHostLayout = true
+				continue
+			}
+			if !c.isValidWasmType(ftyp, siteIndirect) {
 				return false
 			}
 		}
-		return true
+		return hasHostLayout
 	case *types.Pointer:
-		return isValidWasmType(typ.Elem(), siteIndirect)
+		return c.isValidWasmType(typ.Elem(), siteIndirect)
 	}
 	return false
 }

compiler/syscall.go

@@ -5,6 +5,7 @@ package compiler
 
 import (
 	"strconv"
+	"strings"
 
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
@@ -329,3 +330,64 @@ func (b *builder) createRawSyscallNoError(call *ssa.CallCommon) (llvm.Value, err
 	retval = b.CreateInsertValue(retval, llvm.ConstInt(b.uintptrType, 0, false), 1, "")
 	return retval, nil
 }
+
+// Lower a call to internal/abi.FuncPCABI0 on MacOS.
+// This function is called like this:
+//
+//	syscall(abi.FuncPCABI0(libc_mkdir_trampoline), uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
+//
+// So we'll want to return a function pointer (as uintptr) that points to the
+// libc function. Specifically, we _don't_ want to point to the trampoline
+// function (which is implemented in Go assembly which we can't read), but
+// rather to the actually intended function. For this we're going to assume that
+// all the functions follow a specific pattern: libc_<functionname>_trampoline.
+//
+// The return value is the function pointer as an uintptr, or a nil value if
+// this isn't possible (and a regular call should be made as fallback).
+func (b *builder) createDarwinFuncPCABI0Call(instr *ssa.CallCommon) llvm.Value {
+	if b.GOOS != "darwin" {
+		// This has only been tested on MacOS (and only seems to be used there).
+		return llvm.Value{}
+	}
+
+	// Check that it uses a function call like syscall.libc_*_trampoline
+	itf := instr.Args[0].(*ssa.MakeInterface)
+	calledFn := itf.X.(*ssa.Function)
+	if pkgName := calledFn.Pkg.Pkg.Path(); pkgName != "syscall" && pkgName != "internal/syscall/unix" {
+		return llvm.Value{}
+	}
+	if !strings.HasPrefix(calledFn.Name(), "libc_") || !strings.HasSuffix(calledFn.Name(), "_trampoline") {
+
+		return llvm.Value{}
+	}
+
+	// Extract the libc function name.
+	name := strings.TrimPrefix(strings.TrimSuffix(calledFn.Name(), "_trampoline"), "libc_")
+	if name == "open" {
+		// Special case: open() is a variadic function and can't be called like
+		// a regular function. Therefore, we need to use a wrapper implemented
+		// in C.
+		name = "syscall_libc_open"
+	}
+	if b.GOARCH == "amd64" {
+		if name == "fdopendir" || name == "readdir_r" {
+			// Hack to support amd64, which needs the $INODE64 suffix.
+			// This is also done in upstream Go:
+			// https://github.com/golang/go/commit/096ab3c21b88ccc7d411379d09fe6274e3159467
+			name += "$INODE64"
+		}
+	}
+
+	// Obtain the C function.
+	// Use a simple function (no parameters or return value) because all we need
+	// is the address of the function.
+	llvmFn := b.mod.NamedFunction(name)
+	if llvmFn.IsNil() {
+		llvmFnType := llvm.FunctionType(b.ctx.VoidType(), nil, false)
+		llvmFn = llvm.AddFunction(b.mod, name, llvmFnType)
+	}
+
+	// Cast the function pointer to a uintptr (because that's what
+	// abi.FuncPCABI0 returns).
+	return b.CreatePtrToInt(llvmFn, b.uintptrType, "")
+}

compiler/testdata/errors.go

@@ -1,6 +1,9 @@
 package main
 
-import "unsafe"
+import (
+	"structs"
+	"unsafe"
+)
 
 //go:wasmimport modulename empty
 func empty()
@@ -14,31 +17,37 @@ func implementation() {
 type Uint uint32
 
 type S struct {
+	_ structs.HostLayout
 	a [4]uint32
 	b uintptr
-	c int
 	d float32
 	e float64
 }
 
 //go:wasmimport modulename validparam
-func validparam(a int32, b uint64, c float64, d unsafe.Pointer, e Uint, f uintptr, g string, h *int32, i *S)
+func validparam(a int32, b uint64, c float64, d unsafe.Pointer, e Uint, f uintptr, g string, h *int32, i *S, j *struct{}, k *[8]uint8)
 
 // ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type [4]uint32
 // ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type []byte
 // ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type struct{a int}
 // ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type chan struct{}
 // ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type func()
+// ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type int
+// ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type uint
+// ERROR: //go:wasmimport modulename invalidparam: unsupported parameter type [8]int
 //
 //go:wasmimport modulename invalidparam
-func invalidparam(a [4]uint32, b []byte, c struct{ a int }, d chan struct{}, e func())
+func invalidparam(a [4]uint32, b []byte, c struct{ a int }, d chan struct{}, e func(), f int, g uint, h [8]int)
+
+// ERROR: //go:wasmimport modulename invalidparam_no_hostlayout: unsupported parameter type *struct{int}
+// ERROR: //go:wasmimport modulename invalidparam_no_hostlayout: unsupported parameter type *struct{string}
+//
+//go:wasmimport modulename invalidparam_no_hostlayout
+func invalidparam_no_hostlayout(a *struct{ int }, b *struct{ string })
 
 //go:wasmimport modulename validreturn_int32
 func validreturn_int32() int32
 
-//go:wasmimport modulename validreturn_int
-func validreturn_int() int
-
 //go:wasmimport modulename validreturn_ptr_int32
 func validreturn_ptr_int32() *int32
 
@@ -48,6 +57,12 @@ func validreturn_ptr_string() *string
 //go:wasmimport modulename validreturn_ptr_struct
 func validreturn_ptr_struct() *S
 
+//go:wasmimport modulename validreturn_ptr_struct
+func validreturn_ptr_empty_struct() *struct{}
+
+//go:wasmimport modulename validreturn_ptr_array
+func validreturn_ptr_array() *[8]uint8
+
 //go:wasmimport modulename validreturn_unsafe_pointer
 func validreturn_unsafe_pointer() unsafe.Pointer
 
@@ -56,11 +71,26 @@ func validreturn_unsafe_pointer() unsafe.Pointer
 //go:wasmimport modulename manyreturns
 func manyreturns() (int32, int32)
 
+// ERROR: //go:wasmimport modulename invalidreturn_int: unsupported result type int
+//
+//go:wasmimport modulename invalidreturn_int
+func invalidreturn_int() int
+
+// ERROR: //go:wasmimport modulename invalidreturn_int: unsupported result type uint
+//
+//go:wasmimport modulename invalidreturn_int
+func invalidreturn_uint() uint
+
 // ERROR: //go:wasmimport modulename invalidreturn_func: unsupported result type func()
 //
 //go:wasmimport modulename invalidreturn_func
 func invalidreturn_func() func()
 
+// ERROR: //go:wasmimport modulename invalidreturn_pointer_array_int: unsupported result type *[8]int
+//
+//go:wasmimport modulename invalidreturn_pointer_array_int
+func invalidreturn_pointer_array_int() *[8]int
+
 // ERROR: //go:wasmimport modulename invalidreturn_slice_byte: unsupported result type []byte
 //
 //go:wasmimport modulename invalidreturn_slice_byte

compiler/testdata/goroutine-cortex-m-qemu-tasks.ll

@@ -3,8 +3,6 @@ source_filename = "goroutine.go"
 target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "thumbv7m-unknown-unknown-eabi"
 
-%runtime._string = type { ptr, i32 }
-
 @"main$string" = internal unnamed_addr constant [4 x i8] c"test", align 1
 
 ; Function Attrs: allockind("alloc,zeroed") allocsize(0)
@@ -150,12 +148,12 @@ define hidden void @main.startInterfaceMethod(ptr %itf.typecode, ptr %itf.value,
 entry:
   %0 = call align 4 dereferenceable(16) ptr @runtime.alloc(i32 16, ptr null, ptr undef) #9
   store ptr %itf.value, ptr %0, align 4
-  %1 = getelementptr inbounds { ptr, %runtime._string, ptr }, ptr %0, i32 0, i32 1
+  %1 = getelementptr inbounds { ptr, ptr, i32, ptr }, ptr %0, i32 0, i32 1
   store ptr @"main$string", ptr %1, align 4
-  %.repack1 = getelementptr inbounds { ptr, %runtime._string, ptr }, ptr %0, i32 0, i32 1, i32 1
-  store i32 4, ptr %.repack1, align 4
-  %2 = getelementptr inbounds { ptr, %runtime._string, ptr }, ptr %0, i32 0, i32 2
-  store ptr %itf.typecode, ptr %2, align 4
+  %2 = getelementptr inbounds { ptr, ptr, i32, ptr }, ptr %0, i32 0, i32 2
+  store i32 4, ptr %2, align 4
+  %3 = getelementptr inbounds { ptr, ptr, i32, ptr }, ptr %0, i32 0, i32 3
+  store ptr %itf.typecode, ptr %3, align 4
   %stacksize = call i32 @"internal/task.getGoroutineStackSize"(i32 ptrtoint (ptr @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper" to i32), ptr undef) #9
   call void @"internal/task.start"(i32 ptrtoint (ptr @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper" to i32), ptr nonnull %0, i32 %stacksize, ptr undef) #9
   ret void

compiler/testdata/goroutine-wasm-asyncify.ll

@@ -3,8 +3,6 @@ source_filename = "goroutine.go"
 target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"
 
-%runtime._string = type { ptr, i32 }
-
 @"main$string" = internal unnamed_addr constant [4 x i8] c"test", align 1
 
 ; Function Attrs: allockind("alloc,zeroed") allocsize(0)
@@ -161,12 +159,12 @@ entry:
   %0 = call align 4 dereferenceable(16) ptr @runtime.alloc(i32 16, ptr null, ptr undef) #9
   call void @runtime.trackPointer(ptr nonnull %0, ptr nonnull %stackalloc, ptr undef) #9
   store ptr %itf.value, ptr %0, align 4
-  %1 = getelementptr inbounds { ptr, %runtime._string, ptr }, ptr %0, i32 0, i32 1
+  %1 = getelementptr inbounds { ptr, ptr, i32, ptr }, ptr %0, i32 0, i32 1
   store ptr @"main$string", ptr %1, align 4
-  %.repack1 = getelementptr inbounds { ptr, %runtime._string, ptr }, ptr %0, i32 0, i32 1, i32 1
-  store i32 4, ptr %.repack1, align 4
-  %2 = getelementptr inbounds { ptr, %runtime._string, ptr }, ptr %0, i32 0, i32 2
-  store ptr %itf.typecode, ptr %2, align 4
+  %2 = getelementptr inbounds { ptr, ptr, i32, ptr }, ptr %0, i32 0, i32 2
+  store i32 4, ptr %2, align 4
+  %3 = getelementptr inbounds { ptr, ptr, i32, ptr }, ptr %0, i32 0, i32 3
+  store ptr %itf.typecode, ptr %3, align 4
   call void @"internal/task.start"(i32 ptrtoint (ptr @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper" to i32), ptr nonnull %0, i32 65536, ptr undef) #9
   ret void
 }

compiler/testdata/pragma.go

@@ -48,6 +48,22 @@ func inlineFunc() {
 func noinlineFunc() {
 }
 
+type Int interface {
+	int8 | int16
+}
+
+// Same for generic functions (but the compiler may miss the pragma due to it
+// being generic).
+//
+//go:noinline
+func noinlineGenericFunc[T Int]() {
+}
+
+func useGeneric() {
+	// Make sure the generic function above is instantiated.
+	noinlineGenericFunc[int8]()
+}
+
 // This function should have the specified section.
 //
 //go:section .special_function_section

compiler/testdata/pragma.ll

@@ -48,6 +48,19 @@ entry:
   ret void
 }
 
+; Function Attrs: nounwind
+define hidden void @main.useGeneric(ptr %context) unnamed_addr #2 {
+entry:
+  call void @"main.noinlineGenericFunc[int8]"(ptr undef)
+  ret void
+}
+
+; Function Attrs: noinline nounwind
+define linkonce_odr hidden void @"main.noinlineGenericFunc[int8]"(ptr %context) unnamed_addr #5 {
+entry:
+  ret void
+}
+
 ; Function Attrs: noinline nounwind
 define hidden void @main.functionInSection(ptr %context) unnamed_addr #5 section ".special_function_section" {
 entry:

errors_test.go

@@ -24,6 +24,8 @@ func TestErrors(t *testing.T) {
 		{name: "cgo"},
 		{name: "compiler"},
 		{name: "interp"},
+		{name: "invalidmain"},
+		{name: "invalidname"},
 		{name: "linker-flashoverflow", target: "cortex-m-qemu"},
 		{name: "linker-ramoverflow", target: "cortex-m-qemu"},
 		{name: "linker-undefined", target: "darwin/arm64"},

flake.lock

@@ -20,16 +20,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1703068421,
-        "narHash": "sha256-WSw5Faqlw75McIflnl5v7qVD/B3S2sLh+968bpOGrWA=",
+        "lastModified": 1728500571,
+        "narHash": "sha256-dOymOQ3AfNI4Z337yEwHGohrVQb4yPODCW9MDUyAc4w=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "d65bceaee0fb1e64363f7871bc43dc1c6ecad99f",
+        "rev": "d51c28603def282a24fa034bcb007e2bcb5b5dd0",
         "type": "github"
       },
       "original": {
         "id": "nixpkgs",
-        "ref": "nixos-23.11",
+        "ref": "nixos-24.05",
         "type": "indirect"
       }
     },

flake.nix

@@ -35,7 +35,7 @@
   inputs = {
     # Use a recent stable release, but fix the version to make it reproducible.
     # This version should be updated from time to time.
-    nixpkgs.url = "nixpkgs/nixos-23.11";
+    nixpkgs.url = "nixpkgs/nixos-24.05";
     flake-utils.url = "github:numtide/flake-utils";
   };
   outputs = { self, nixpkgs, flake-utils }:
@@ -49,11 +49,11 @@
           buildInputs = [
             # These dependencies are required for building tinygo (go install).
             go
-            llvmPackages_17.llvm
-            llvmPackages_17.libclang
+            llvmPackages_18.llvm
+            llvmPackages_18.libclang
             # Additional dependencies needed at runtime, for building and/or
             # flashing.
-            llvmPackages_17.lld
+            llvmPackages_18.lld
             avrdude
             binaryen
             # Additional dependencies needed for on-chip debugging.
@@ -68,7 +68,7 @@
             # Without setting these explicitly, Homebrew versions might be used
             # or the default `ar` and `nm` tools might be used (which don't
             # support wasi).
-            export CLANG="clang-17 -resource-dir ${llvmPackages_17.clang.cc.lib}/lib/clang/17"
+            export CLANG="clang-18 -resource-dir ${llvmPackages_18.clang.cc.lib}/lib/clang/18"
             export LLVM_AR=llvm-ar
             export LLVM_NM=llvm-nm
 
@@ -77,7 +77,7 @@
             export MD5SUM=md5sum
 
             # Ugly hack to make the Clang resources directory available.
-            export GOFLAGS="\"-ldflags=-X github.com/tinygo-org/tinygo/goenv.clangResourceDir=${llvmPackages_17.clang.cc.lib}/lib/clang/17\" -tags=llvm17"
+            export GOFLAGS="\"-ldflags=-X github.com/tinygo-org/tinygo/goenv.clangResourceDir=${llvmPackages_18.clang.cc.lib}/lib/clang/18\" -tags=llvm18"
           '';
         };
       }

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/mattn/go-colorable v0.1.13
 	github.com/mattn/go-tty v0.0.4
 	github.com/sigurn/crc16 v0.0.0-20211026045750-20ab5afb07e3
+	github.com/tetratelabs/wazero v1.6.0
 	go.bug.st/serial v1.6.0
 	golang.org/x/net v0.26.0
 	golang.org/x/sys v0.21.0

go.sum

@@ -12,7 +12,6 @@ github.com/chromedp/sysutil v1.0.0/go.mod h1:kgWmDdq8fTzXYcKIBqIYvRRTnYb9aNS9moA
 github.com/creack/goselect v0.1.2 h1:2DNy14+JPjRBgPzAd1thbQp4BSIihxcBf0IXhQXDRa0=
 github.com/creack/goselect v0.1.2/go.mod h1:a/NhLweNvqIYMuxcMOuWY516Cimucms3DglDzQP3hKY=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gobwas/httphead v0.1.0 h1:exrUm0f4YX0L7EBwZHuCF4GDp8aJfVeBrlLQrs6NqWU=
 github.com/gobwas/httphead v0.1.0/go.mod h1:O/RXo79gxV8G+RqlR/otEwx4Q36zl9rqC5u12GKvMCM=
 github.com/gobwas/pool v0.2.1 h1:xfeeEhW7pwmX8nuLVlqbzVc7udMDrwetjEv+TZIz1og=
@@ -45,19 +44,18 @@ github.com/mattn/go-tty v0.0.4/go.mod h1:u5GGXBtZU6RQoKV8gY5W6UhMudbR5vXnUe7j3px
 github.com/orisano/pixelmatch v0.0.0-20210112091706-4fa4c7ba91d5 h1:1SoBaSPudixRecmlHXb/GxmaD3fLMtHIDN13QujwQuc=
 github.com/orisano/pixelmatch v0.0.0-20210112091706-4fa4c7ba91d5/go.mod h1:nZgzbfBr3hhjoZnS66nKrHmduYNpc34ny7RK4z5/HM0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sigurn/crc16 v0.0.0-20211026045750-20ab5afb07e3 h1:aQKxg3+2p+IFXXg97McgDGT5zcMrQoi0EICZs8Pgchs=
 github.com/sigurn/crc16 v0.0.0-20211026045750-20ab5afb07e3/go.mod h1:9/etS5gpQq9BJsJMWg1wpLbfuSnkm8dPF6FdW2JXVhA=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/tetratelabs/wazero v1.6.0 h1:z0H1iikCdP8t+q341xqepY4EWvHEw8Es7tlqiVzlP3g=
+github.com/tetratelabs/wazero v1.6.0/go.mod h1:0U0G41+ochRKoPKCJlh0jMg1CHkyfK8kDqiirMmKY8A=
 go.bug.st/serial v1.6.0 h1:mAbRGN4cKE2J5gMwsMHC2KQisdLRQssO9WSM+rbZJ8A=
 go.bug.st/serial v1.6.0/go.mod h1:UABfsluHAiaNI+La2iESysd9Vetq7VRdpxvjx7CmmOE=
 golang.org/x/mod v0.18.0 h1:5+9lSbEzPSdWkH32vYPBwEpX8KwDbM52Ud9xBUvNlb0=
-golang.org/x/mod v0.18.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
 golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
 golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
-golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -76,6 +74,5 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 tinygo.org/x/go-llvm v0.0.0-20240627184919-3b50c76783a8 h1:bLsZXRUBavt++CJlMN7sppNziqu3LyamESLhFJcpqFQ=
 tinygo.org/x/go-llvm v0.0.0-20240627184919-3b50c76783a8/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=

goenv/version.go

@@ -9,7 +9,7 @@ import (
 
 // Version of TinyGo.
 // Update this value before release of new version of software.
-const version = "0.33.0"
+const version = "0.34.0"
 
 var (
 	// This variable is set at build time using -ldflags parameters.
@@ -34,27 +34,64 @@ func GetGorootVersion() (major, minor int, err error) {
 	if err != nil {
 		return 0, 0, err
 	}
+	major, minor, _, err = Parse(s)
+	return major, minor, err
+}
 
-	if s == "" || s[:2] != "go" {
-		return 0, 0, errors.New("could not parse Go version: version does not start with 'go' prefix")
+// Parse parses the Go version (like "go1.3.2") in the parameter and return the
+// major, minor, and patch version: 1, 3, and 2 in this example.
+// If there is an error, (0, 0, 0) and an error will be returned.
+func Parse(version string) (major, minor, patch int, err error) {
+	if version == "" || version[:2] != "go" {
+		return 0, 0, 0, errors.New("could not parse Go version: version does not start with 'go' prefix")
 	}
 
-	parts := strings.Split(s[2:], ".")
+	parts := strings.Split(version[2:], ".")
 	if len(parts) < 2 {
-		return 0, 0, errors.New("could not parse Go version: version has less than two parts")
+		return 0, 0, 0, errors.New("could not parse Go version: version has less than two parts")
 	}
 
 	// Ignore the errors, we don't really handle errors here anyway.
 	var trailing string
-	n, err := fmt.Sscanf(s, "go%d.%d%s", &major, &minor, &trailing)
-	if n == 2 && err == io.EOF {
+	n, err := fmt.Sscanf(version, "go%d.%d.%d%s", &major, &minor, &patch, &trailing)
+	if n == 2 {
+		n, err = fmt.Sscanf(version, "go%d.%d%s", &major, &minor, &trailing)
+	}
+	if n >= 2 && err == io.EOF {
 		// Means there were no trailing characters (i.e., not an alpha/beta)
 		err = nil
 	}
 	if err != nil {
-		return 0, 0, fmt.Errorf("failed to parse version: %s", err)
+		return 0, 0, 0, fmt.Errorf("failed to parse version: %s", err)
+	}
+
+	return major, minor, patch, nil
+}
+
+// Compare compares two Go version strings.
+// The result will be 0 if a == b, -1 if a < b, and +1 if a > b.
+// If either a or b is not a valid Go version, it is treated as "go0.0"
+// and compared lexicographically.
+// See [Parse] for more information.
+func Compare(a, b string) int {
+	aMajor, aMinor, aPatch, _ := Parse(a)
+	bMajor, bMinor, bPatch, _ := Parse(b)
+	switch {
+	case aMajor < bMajor:
+		return -1
+	case aMajor > bMajor:
+		return +1
+	case aMinor < bMinor:
+		return -1
+	case aMinor > bMinor:
+		return +1
+	case aPatch < bPatch:
+		return -1
+	case aPatch > bPatch:
+		return +1
+	default:
+		return strings.Compare(a, b)
 	}
-	return
 }
 
 // GorootVersionString returns the version string as reported by the Go

goenv/version_test.go

@@ -0,0 +1,71 @@
+package goenv
+
+import "testing"
+
+func TestParse(t *testing.T) {
+	tests := []struct {
+		v       string
+		major   int
+		minor   int
+		patch   int
+		wantErr bool
+	}{
+		{"", 0, 0, 0, true},
+		{"go", 0, 0, 0, true},
+		{"go1", 0, 0, 0, true},
+		{"go.0", 0, 0, 0, true},
+		{"go1.0", 1, 0, 0, false},
+		{"go1.1", 1, 1, 0, false},
+		{"go1.23", 1, 23, 0, false},
+		{"go1.23.5", 1, 23, 5, false},
+		{"go1.23.5-rc6", 1, 23, 5, false},
+		{"go2.0", 2, 0, 0, false},
+		{"go2.0.15", 2, 0, 15, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.v, func(t *testing.T) {
+			major, minor, patch, err := Parse(tt.v)
+			if err == nil && tt.wantErr {
+				t.Errorf("Parse(%q): expected err != nil", tt.v)
+			}
+			if err != nil && !tt.wantErr {
+				t.Errorf("Parse(%q): expected err == nil", tt.v)
+			}
+			if major != tt.major || minor != tt.minor || patch != tt.patch {
+				t.Errorf("Parse(%q): expected %d, %d, %d, nil; got %d, %d, %d, %v",
+					tt.v, tt.major, tt.minor, tt.patch, major, minor, patch, err)
+			}
+		})
+	}
+}
+
+func TestCompare(t *testing.T) {
+	tests := []struct {
+		a    string
+		b    string
+		want int
+	}{
+		{"", "", 0},
+		{"go0", "go0", 0},
+		{"go0", "go1", -1},
+		{"go1", "go0", 1},
+		{"go1", "go2", -1},
+		{"go2", "go1", 1},
+		{"go1.1", "go1.2", -1},
+		{"go1.2", "go1.1", 1},
+		{"go1.1.0", "go1.2.0", -1},
+		{"go1.2.0", "go1.1.0", 1},
+		{"go1.2.0", "go2.3.0", -1},
+		{"go1.23.2", "go1.23.10", -1},
+		{"go0.1.22", "go1.23.101", -1},
+	}
+	for _, tt := range tests {
+		t.Run(tt.a+" "+tt.b, func(t *testing.T) {
+			got := Compare(tt.a, tt.b)
+			if got != tt.want {
+				t.Errorf("Compare(%q, %q): expected %d; got %d",
+					tt.a, tt.b, tt.want, got)
+			}
+		})
+	}
+}

internal/wasm-tools/go.mod

@@ -2,11 +2,18 @@ module github.com/tinygo-org/tinygo/internal/tools
 
 go 1.22.4
 
-require github.com/ydnar/wasm-tools-go v0.1.4
+require github.com/bytecodealliance/wasm-tools-go v0.3.0
 
 require (
 	github.com/coreos/go-semver v0.3.1 // indirect
+	github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
+	github.com/opencontainers/go-digest v1.0.0 // indirect
+	github.com/regclient/regclient v0.7.1 // indirect
+	github.com/sirupsen/logrus v1.9.3 // indirect
+	github.com/ulikunitz/xz v0.5.12 // indirect
 	github.com/urfave/cli/v3 v3.0.0-alpha9 // indirect
 	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
-	golang.org/x/mod v0.19.0 // indirect
+	golang.org/x/mod v0.21.0 // indirect
+	golang.org/x/sys v0.26.0 // indirect
 )

internal/wasm-tools/go.sum

@@ -1,25 +1,46 @@
+github.com/bytecodealliance/wasm-tools-go v0.3.0 h1:9aeDFYpbi3gtIW/nJCH+P+LhFMqezGoOfzqbUZLadho=
+github.com/bytecodealliance/wasm-tools-go v0.3.0/go.mod h1:VY+9FlpLi6jnhCrZLkyJjF9rjU4aEekgaRTk28MS2JE=
 github.com/coreos/go-semver v0.3.1 h1:yi21YpKnrx1gt5R+la8n5WgS0kCrsPp33dmEyHReZr4=
 github.com/coreos/go-semver v0.3.1/go.mod h1:irMmmIw/7yzSRPWryHsK7EYSg09caPQL03VsM8rvUec=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 h1:UhxFibDNY/bfvqU5CAUmr9zpesgbU6SWc8/B4mflAE4=
+github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7/go.mod h1:cyGadeNEkKy96OOhEzfZl+yxihPEzKnqJwvfuSUqbZE=
+github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
+github.com/olareg/olareg v0.1.0 h1:1dXBOgPrig5N7zoXyIZVQqU0QBo6sD9pbL6UYjY75CA=
+github.com/olareg/olareg v0.1.0/go.mod h1:RBuU7JW7SoIIxZKzLRhq8sVtQeAHzCAtRrXEBx2KlM4=
+github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
+github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/regclient/regclient v0.7.1 h1:qEsJrTmZd98fZKjueAbrZCSNGU+ifnr6xjlSAs3WOPs=
+github.com/regclient/regclient v0.7.1/go.mod h1:+w/BFtJuw0h0nzIw/z2+1FuA2/dVXBzDq4rYmziJpMc=
 github.com/sergi/go-diff v1.3.1 h1:xkr+Oxo4BOQKmkn/B9eMK0g5Kg/983T9DqqPHwYqD+8=
 github.com/sergi/go-diff v1.3.1/go.mod h1:aMJSSKb2lpPvRNec0+w3fl7LP9IOFzdc9Pa4NFbPK1I=
+github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/ulikunitz/xz v0.5.12 h1:37Nm15o69RwBkXM0J6A5OlE67RZTfzUxTj8fB3dfcsc=
+github.com/ulikunitz/xz v0.5.12/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
 github.com/urfave/cli/v3 v3.0.0-alpha9 h1:P0RMy5fQm1AslQS+XCmy9UknDXctOmG/q/FZkUFnJSo=
 github.com/urfave/cli/v3 v3.0.0-alpha9/go.mod h1:0kK/RUFHyh+yIKSfWxwheGndfnrvYSmYFVeKCh03ZUc=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
-github.com/ydnar/wasm-tools-go v0.1.4 h1:+25WqBj0AhLx8OFvZvrs7bQO6L3WtQ7t6JzQEYsXQb8=
-github.com/ydnar/wasm-tools-go v0.1.4/go.mod h1:lQfv2Tde3tRgZDSYriro0EmdSHzP1mrHPMmYNahSS/g=
-golang.org/x/mod v0.19.0 h1:fEdghXQSo20giMthA7cd28ZC+jts4amQ3YMXiP5oMQ8=
-golang.org/x/mod v0.19.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
-golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
-golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/tools v0.23.0 h1:SGsXPZ+2l4JsgaCKkx+FQ9YZ5XEtA1GZYuoDjenLjvg=
-golang.org/x/tools v0.23.0/go.mod h1:pnu6ufv6vQkll6szChhK3C3L/ruaIv5eBeztNG8wtsI=
+golang.org/x/mod v0.21.0 h1:vvrHzRwRfVKSiLrG+d4FMl/Qi4ukBCE6kZlTUkDYRT0=
+golang.org/x/mod v0.21.0/go.mod h1:6SkKJ3Xj0I0BrPOZoBy3bdMptDDU9oJrpohJ3eWZ1fY=
+golang.org/x/sync v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ=
+golang.org/x/sync v0.8.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.26.0 h1:KHjCJyddX0LoSTb3J+vWpupP9p0oznkqVk/IfjymZbo=
+golang.org/x/sys v0.26.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/tools v0.26.0 h1:v/60pFQmzmT9ExmjDv2gGIfi3OqfKoEP6I5+umXlbnQ=
+golang.org/x/tools v0.26.0/go.mod h1:TPVVj70c7JJ3WCazhD8OdXcZg/og+b9+tH/KxylGwH0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/wasm-tools/tools.go

@@ -5,7 +5,7 @@
 package tools
 
 import (
-	_ "github.com/ydnar/wasm-tools-go/cmd/wit-bindgen-go"
+	_ "github.com/bytecodealliance/wasm-tools-go/cmd/wit-bindgen-go"
 )
 
-//go:generate go install github.com/ydnar/wasm-tools-go/cmd/wit-bindgen-go
+//go:generate go install github.com/bytecodealliance/wasm-tools-go/cmd/wit-bindgen-go

interp/interp.go

@@ -3,11 +3,13 @@
 package interp
 
 import (
+	"encoding/binary"
 	"fmt"
 	"os"
 	"strings"
 	"time"
 
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"tinygo.org/x/go-llvm"
 )
 
@@ -24,6 +26,7 @@ type runner struct {
 	dataPtrType   llvm.Type                // often used type so created in advance
 	uintptrType   llvm.Type                // equivalent to uintptr in Go
 	maxAlign      int                      // maximum alignment of an object, alignment of runtime.alloc() result
+	byteOrder     binary.ByteOrder         // big-endian or little-endian
 	debug         bool                     // log debug messages
 	pkgName       string                   // package name of the currently executing package
 	functionCache map[llvm.Value]*function // cache of compiled functions
@@ -38,6 +41,7 @@ func newRunner(mod llvm.Module, timeout time.Duration, debug bool) *runner {
 	r := runner{
 		mod:           mod,
 		targetData:    llvm.NewTargetData(mod.DataLayout()),
+		byteOrder:     llvmutil.ByteOrder(mod.Target()),
 		debug:         debug,
 		functionCache: make(map[llvm.Value]*function),
 		objects:       []object{{}},

interp/interpreter.go

@@ -173,7 +173,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			case 3:
 				// Conditional branch: [cond, thenBB, elseBB]
 				lastBB = currentBB
-				switch operands[0].Uint() {
+				switch operands[0].Uint(r) {
 				case 1: // true -> thenBB
 					currentBB = int(operands[1].(literalValue).value.(uint32))
 				case 0: // false -> elseBB
@@ -191,12 +191,12 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			}
 		case llvm.Switch:
 			// Switch statement: [value, defaultLabel, case0, label0, case1, label1, ...]
-			value := operands[0].Uint()
-			targetLabel := operands[1].Uint() // default label
+			value := operands[0].Uint(r)
+			targetLabel := operands[1].Uint(r) // default label
 			// Do a lazy switch by iterating over all cases.
 			for i := 2; i < len(operands); i += 2 {
-				if value == operands[i].Uint() {
-					targetLabel = operands[i+1].Uint()
+				if value == operands[i].Uint(r) {
+					targetLabel = operands[i+1].Uint(r)
 					break
 				}
 			}
@@ -211,7 +211,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			// Select is much like a ternary operator: it picks a result from
 			// the second and third operand based on the boolean first operand.
 			var result value
-			switch operands[0].Uint() {
+			switch operands[0].Uint(r) {
 			case 1:
 				result = operands[1]
 			case 0:
@@ -282,7 +282,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				// by creating a global variable.
 
 				// Get the requested memory size to be allocated.
-				size := operands[1].Uint()
+				size := operands[1].Uint(r)
 
 				// Get the object layout, if it is available.
 				llvmLayoutType := r.getLLVMTypeFromLayout(operands[2])
@@ -318,9 +318,9 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				//     memmove(dst, src, n*elemSize)
 				//     return int(n)
 				// }
-				dstLen := operands[3].Uint()
-				srcLen := operands[4].Uint()
-				elemSize := operands[5].Uint()
+				dstLen := operands[3].Uint(r)
+				srcLen := operands[4].Uint(r)
+				elemSize := operands[5].Uint(r)
 				n := srcLen
 				if n > dstLen {
 					n = dstLen
@@ -374,7 +374,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
-				nBytes := uint32(operands[3].Uint())
+				nBytes := uint32(operands[3].Uint(r))
 				dstObj := mem.getWritable(dst.index())
 				dstBuf := dstObj.buffer.asRawValue(r)
 				if mem.get(src.index()).buffer == nil {
@@ -661,8 +661,8 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			// pointer into the underlying object.
 			var offset int64
 			for i := 1; i < len(operands); i += 2 {
-				index := operands[i].Int()
-				elementSize := operands[i+1].Int()
+				index := operands[i].Int(r)
+				elementSize := operands[i+1].Int(r)
 				if elementSize < 0 {
 					// This is a struct field.
 					offset += index
@@ -677,7 +677,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 					return nil, mem, r.errorAt(inst, err)
 				}
 				// GEP on fixed pointer value (for example, memory-mapped I/O).
-				ptrValue := operands[0].Uint() + uint64(offset)
+				ptrValue := operands[0].Uint(r) + uint64(offset)
 				locals[inst.localIndex] = makeLiteralInt(ptrValue, int(operands[0].len(r)*8))
 				continue
 			}
@@ -739,11 +739,11 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			var lhs, rhs float64
 			switch operands[0].len(r) {
 			case 8:
-				lhs = math.Float64frombits(operands[0].Uint())
-				rhs = math.Float64frombits(operands[1].Uint())
+				lhs = math.Float64frombits(operands[0].Uint(r))
+				rhs = math.Float64frombits(operands[1].Uint(r))
 			case 4:
-				lhs = float64(math.Float32frombits(uint32(operands[0].Uint())))
-				rhs = float64(math.Float32frombits(uint32(operands[1].Uint())))
+				lhs = float64(math.Float32frombits(uint32(operands[0].Uint(r))))
+				rhs = float64(math.Float32frombits(uint32(operands[1].Uint(r))))
 			default:
 				panic("unknown float type")
 			}
@@ -782,23 +782,23 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				if inst.opcode == llvm.Add {
 					// This likely means this is part of a
 					// unsafe.Pointer(uintptr(ptr) + offset) pattern.
-					lhsPtr, err = lhsPtr.addOffset(int64(rhs.Uint()))
+					lhsPtr, err = lhsPtr.addOffset(int64(rhs.Uint(r)))
 					if err != nil {
 						return nil, mem, r.errorAt(inst, err)
 					}
 					locals[inst.localIndex] = lhsPtr
-				} else if inst.opcode == llvm.Xor && rhs.Uint() == 0 {
+				} else if inst.opcode == llvm.Xor && rhs.Uint(r) == 0 {
 					// Special workaround for strings.noescape, see
 					// src/strings/builder.go in the Go source tree. This is
 					// the identity operator, so we can return the input.
 					locals[inst.localIndex] = lhs
-				} else if inst.opcode == llvm.And && rhs.Uint() < 8 {
+				} else if inst.opcode == llvm.And && rhs.Uint(r) < 8 {
 					// This is probably part of a pattern to get the lower bits
 					// of a pointer for pointer tagging, like this:
 					//     uintptr(unsafe.Pointer(t)) & 0b11
 					// We can actually support this easily by ANDing with the
 					// pointer offset.
-					result := uint64(lhsPtr.offset()) & rhs.Uint()
+					result := uint64(lhsPtr.offset()) & rhs.Uint(r)
 					locals[inst.localIndex] = makeLiteralInt(result, int(lhs.len(r)*8))
 				} else {
 					// Catch-all for weird operations that should just be done
@@ -813,31 +813,31 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			var result uint64
 			switch inst.opcode {
 			case llvm.Add:
-				result = lhs.Uint() + rhs.Uint()
+				result = lhs.Uint(r) + rhs.Uint(r)
 			case llvm.Sub:
-				result = lhs.Uint() - rhs.Uint()
+				result = lhs.Uint(r) - rhs.Uint(r)
 			case llvm.Mul:
-				result = lhs.Uint() * rhs.Uint()
+				result = lhs.Uint(r) * rhs.Uint(r)
 			case llvm.UDiv:
-				result = lhs.Uint() / rhs.Uint()
+				result = lhs.Uint(r) / rhs.Uint(r)
 			case llvm.SDiv:
-				result = uint64(lhs.Int() / rhs.Int())
+				result = uint64(lhs.Int(r) / rhs.Int(r))
 			case llvm.URem:
-				result = lhs.Uint() % rhs.Uint()
+				result = lhs.Uint(r) % rhs.Uint(r)
 			case llvm.SRem:
-				result = uint64(lhs.Int() % rhs.Int())
+				result = uint64(lhs.Int(r) % rhs.Int(r))
 			case llvm.Shl:
-				result = lhs.Uint() << rhs.Uint()
+				result = lhs.Uint(r) << rhs.Uint(r)
 			case llvm.LShr:
-				result = lhs.Uint() >> rhs.Uint()
+				result = lhs.Uint(r) >> rhs.Uint(r)
 			case llvm.AShr:
-				result = uint64(lhs.Int() >> rhs.Uint())
+				result = uint64(lhs.Int(r) >> rhs.Uint(r))
 			case llvm.And:
-				result = lhs.Uint() & rhs.Uint()
+				result = lhs.Uint(r) & rhs.Uint(r)
 			case llvm.Or:
-				result = lhs.Uint() | rhs.Uint()
+				result = lhs.Uint(r) | rhs.Uint(r)
 			case llvm.Xor:
-				result = lhs.Uint() ^ rhs.Uint()
+				result = lhs.Uint(r) ^ rhs.Uint(r)
 			default:
 				panic("unreachable")
 			}
@@ -855,11 +855,11 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			// and then truncating it as necessary.
 			var value uint64
 			if inst.opcode == llvm.SExt {
-				value = uint64(operands[0].Int())
+				value = uint64(operands[0].Int(r))
 			} else {
-				value = operands[0].Uint()
+				value = operands[0].Uint(r)
 			}
-			bitwidth := operands[1].Uint()
+			bitwidth := operands[1].Uint(r)
 			if r.debug {
 				fmt.Fprintln(os.Stderr, indent+instructionNameMap[inst.opcode]+":", value, bitwidth)
 			}
@@ -868,11 +868,11 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			var value float64
 			switch inst.opcode {
 			case llvm.SIToFP:
-				value = float64(operands[0].Int())
+				value = float64(operands[0].Int(r))
 			case llvm.UIToFP:
-				value = float64(operands[0].Uint())
+				value = float64(operands[0].Uint(r))
 			}
-			bitwidth := operands[1].Uint()
+			bitwidth := operands[1].Uint(r)
 			if r.debug {
 				fmt.Fprintln(os.Stderr, indent+instructionNameMap[inst.opcode]+":", value, bitwidth)
 			}
@@ -918,21 +918,21 @@ func (r *runner) interpretICmp(lhs, rhs value, predicate llvm.IntPredicate) bool
 		}
 		return result
 	case llvm.IntUGT:
-		return lhs.Uint() > rhs.Uint()
+		return lhs.Uint(r) > rhs.Uint(r)
 	case llvm.IntUGE:
-		return lhs.Uint() >= rhs.Uint()
+		return lhs.Uint(r) >= rhs.Uint(r)
 	case llvm.IntULT:
-		return lhs.Uint() < rhs.Uint()
+		return lhs.Uint(r) < rhs.Uint(r)
 	case llvm.IntULE:
-		return lhs.Uint() <= rhs.Uint()
+		return lhs.Uint(r) <= rhs.Uint(r)
 	case llvm.IntSGT:
-		return lhs.Int() > rhs.Int()
+		return lhs.Int(r) > rhs.Int(r)
 	case llvm.IntSGE:
-		return lhs.Int() >= rhs.Int()
+		return lhs.Int(r) >= rhs.Int(r)
 	case llvm.IntSLT:
-		return lhs.Int() < rhs.Int()
+		return lhs.Int(r) < rhs.Int(r)
 	case llvm.IntSLE:
-		return lhs.Int() <= rhs.Int()
+		return lhs.Int(r) <= rhs.Int(r)
 	default:
 		// _should_ be unreachable, until LLVM adds new icmp operands (unlikely)
 		panic("interp: unsupported icmp")

interp/memory.go

@@ -361,8 +361,8 @@ type value interface {
 	clone() value
 	asPointer(*runner) (pointerValue, error)
 	asRawValue(*runner) rawValue
-	Uint() uint64
-	Int() int64
+	Uint(*runner) uint64
+	Int(*runner) int64
 	toLLVMValue(llvm.Type, *memoryView) (llvm.Value, error)
 	String() string
 }
@@ -405,7 +405,8 @@ func (v literalValue) len(r *runner) uint32 {
 }
 
 func (v literalValue) String() string {
-	return strconv.FormatInt(v.Int(), 10)
+	// Note: passing a nil *runner to v.Int because we know it won't use it.
+	return strconv.FormatInt(v.Int(nil), 10)
 }
 
 func (v literalValue) clone() value {
@@ -421,13 +422,13 @@ func (v literalValue) asRawValue(r *runner) rawValue {
 	switch value := v.value.(type) {
 	case uint64:
 		buf = make([]byte, 8)
-		binary.LittleEndian.PutUint64(buf, value)
+		r.byteOrder.PutUint64(buf, value)
 	case uint32:
 		buf = make([]byte, 4)
-		binary.LittleEndian.PutUint32(buf, uint32(value))
+		r.byteOrder.PutUint32(buf, uint32(value))
 	case uint16:
 		buf = make([]byte, 2)
-		binary.LittleEndian.PutUint16(buf, uint16(value))
+		r.byteOrder.PutUint16(buf, uint16(value))
 	case uint8:
 		buf = []byte{uint8(value)}
 	default:
@@ -440,7 +441,7 @@ func (v literalValue) asRawValue(r *runner) rawValue {
 	return raw
 }
 
-func (v literalValue) Uint() uint64 {
+func (v literalValue) Uint(r *runner) uint64 {
 	switch value := v.value.(type) {
 	case uint64:
 		return value
@@ -455,7 +456,7 @@ func (v literalValue) Uint() uint64 {
 	}
 }
 
-func (v literalValue) Int() int64 {
+func (v literalValue) Int(r *runner) int64 {
 	switch value := v.value.(type) {
 	case uint64:
 		return int64(value)
@@ -553,11 +554,11 @@ func (v pointerValue) asRawValue(r *runner) rawValue {
 	return rv
 }
 
-func (v pointerValue) Uint() uint64 {
+func (v pointerValue) Uint(r *runner) uint64 {
 	panic("cannot convert pointer to integer")
 }
 
-func (v pointerValue) Int() int64 {
+func (v pointerValue) Int(r *runner) int64 {
 	panic("cannot convert pointer to integer")
 }
 
@@ -702,7 +703,12 @@ func (v rawValue) String() string {
 		}
 		// Format as number if none of the buf is a pointer.
 		if !v.hasPointer() {
-			return strconv.FormatInt(v.Int(), 10)
+			// Construct a fake runner, which is little endian.
+			// We only use String() for debugging, so this is is good enough
+			// (the printed value will just be slightly wrong when debugging the
+			// interp package with GOOS=mips for example).
+			r := &runner{byteOrder: binary.LittleEndian}
+			return strconv.FormatInt(v.Int(r), 10)
 		}
 	}
 	return "<[…" + strconv.Itoa(len(v.buf)) + "]>"
@@ -738,33 +744,33 @@ func (v rawValue) bytes() []byte {
 	return buf
 }
 
-func (v rawValue) Uint() uint64 {
+func (v rawValue) Uint(r *runner) uint64 {
 	buf := v.bytes()
 
 	switch len(v.buf) {
 	case 1:
 		return uint64(buf[0])
 	case 2:
-		return uint64(binary.LittleEndian.Uint16(buf))
+		return uint64(r.byteOrder.Uint16(buf))
 	case 4:
-		return uint64(binary.LittleEndian.Uint32(buf))
+		return uint64(r.byteOrder.Uint32(buf))
 	case 8:
-		return binary.LittleEndian.Uint64(buf)
+		return r.byteOrder.Uint64(buf)
 	default:
 		panic("unknown integer size")
 	}
 }
 
-func (v rawValue) Int() int64 {
+func (v rawValue) Int(r *runner) int64 {
 	switch len(v.buf) {
 	case 1:
-		return int64(int8(v.Uint()))
+		return int64(int8(v.Uint(r)))
 	case 2:
-		return int64(int16(v.Uint()))
+		return int64(int16(v.Uint(r)))
 	case 4:
-		return int64(int32(v.Uint()))
+		return int64(int32(v.Uint(r)))
 	case 8:
-		return int64(int64(v.Uint()))
+		return int64(int64(v.Uint(r)))
 	default:
 		panic("unknown integer size")
 	}
@@ -878,11 +884,11 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) (llvm.Value,
 		var n uint64
 		switch llvmType.IntTypeWidth() {
 		case 64:
-			n = rawValue{v.buf[:8]}.Uint()
+			n = rawValue{v.buf[:8]}.Uint(mem.r)
 		case 32:
-			n = rawValue{v.buf[:4]}.Uint()
+			n = rawValue{v.buf[:4]}.Uint(mem.r)
 		case 16:
-			n = rawValue{v.buf[:2]}.Uint()
+			n = rawValue{v.buf[:2]}.Uint(mem.r)
 		case 8:
 			n = uint64(v.buf[0])
 		case 1:
@@ -951,7 +957,7 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) (llvm.Value,
 		}
 		// This is either a null pointer or a raw pointer for memory-mapped I/O
 		// (such as 0xe000ed00).
-		ptr := rawValue{v.buf[:mem.r.pointerSize]}.Uint()
+		ptr := rawValue{v.buf[:mem.r.pointerSize]}.Uint(mem.r)
 		if ptr == 0 {
 			// Null pointer.
 			return llvm.ConstNull(llvmType), nil
@@ -969,11 +975,11 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) (llvm.Value,
 		}
 		return llvm.ConstIntToPtr(ptrValue, llvmType), nil
 	case llvm.DoubleTypeKind:
-		b := rawValue{v.buf[:8]}.Uint()
+		b := rawValue{v.buf[:8]}.Uint(mem.r)
 		f := math.Float64frombits(b)
 		return llvm.ConstFloat(llvmType, f), nil
 	case llvm.FloatTypeKind:
-		b := uint32(rawValue{v.buf[:4]}.Uint())
+		b := uint32(rawValue{v.buf[:4]}.Uint(mem.r))
 		f := math.Float32frombits(b)
 		return llvm.ConstFloat(llvmType, float64(f)), nil
 	default:
@@ -1065,19 +1071,19 @@ func (v *rawValue) set(llvmValue llvm.Value, r *runner) {
 			switch llvmValue.Type().IntTypeWidth() {
 			case 64:
 				var buf [8]byte
-				binary.LittleEndian.PutUint64(buf[:], n)
+				r.byteOrder.PutUint64(buf[:], n)
 				for i, b := range buf {
 					v.buf[i] = uint64(b)
 				}
 			case 32:
 				var buf [4]byte
-				binary.LittleEndian.PutUint32(buf[:], uint32(n))
+				r.byteOrder.PutUint32(buf[:], uint32(n))
 				for i, b := range buf {
 					v.buf[i] = uint64(b)
 				}
 			case 16:
 				var buf [2]byte
-				binary.LittleEndian.PutUint16(buf[:], uint16(n))
+				r.byteOrder.PutUint16(buf[:], uint16(n))
 				for i, b := range buf {
 					v.buf[i] = uint64(b)
 				}
@@ -1109,14 +1115,14 @@ func (v *rawValue) set(llvmValue llvm.Value, r *runner) {
 		case llvm.DoubleTypeKind:
 			f, _ := llvmValue.DoubleValue()
 			var buf [8]byte
-			binary.LittleEndian.PutUint64(buf[:], math.Float64bits(f))
+			r.byteOrder.PutUint64(buf[:], math.Float64bits(f))
 			for i, b := range buf {
 				v.buf[i] = uint64(b)
 			}
 		case llvm.FloatTypeKind:
 			f, _ := llvmValue.DoubleValue()
 			var buf [4]byte
-			binary.LittleEndian.PutUint32(buf[:], math.Float32bits(float32(f)))
+			r.byteOrder.PutUint32(buf[:], math.Float32bits(float32(f)))
 			for i, b := range buf {
 				v.buf[i] = uint64(b)
 			}
@@ -1166,11 +1172,11 @@ func (v localValue) asRawValue(r *runner) rawValue {
 	panic("interp: localValue.asRawValue")
 }
 
-func (v localValue) Uint() uint64 {
+func (v localValue) Uint(r *runner) uint64 {
 	panic("interp: localValue.Uint")
 }
 
-func (v localValue) Int() int64 {
+func (v localValue) Int(r *runner) int64 {
 	panic("interp: localValue.Int")
 }
 
@@ -1254,7 +1260,7 @@ func (r *runner) readObjectLayout(layoutValue value) (uint64, *big.Int) {
 	ptr, err := layoutValue.asPointer(r)
 	if err == errIntegerAsPointer {
 		// It's an integer, which means it's a small object or unknown.
-		layout := layoutValue.Uint()
+		layout := layoutValue.Uint(r)
 		if layout == 0 {
 			// Nil pointer, which means the layout is unknown.
 			return 0, nil
@@ -1287,7 +1293,7 @@ func (r *runner) readObjectLayout(layoutValue value) (uint64, *big.Int) {
 
 	// Read the object size in words and the bitmap from the global.
 	buf := r.objects[ptr.index()].buffer.(rawValue)
-	objectSizeWords := rawValue{buf: buf.buf[:r.pointerSize]}.Uint()
+	objectSizeWords := rawValue{buf: buf.buf[:r.pointerSize]}.Uint(r)
 	rawByteValues := buf.buf[r.pointerSize:]
 	rawBytes := make([]byte, len(rawByteValues))
 	for i, v := range rawByteValues {

loader/goroot.go

@@ -218,7 +218,7 @@ func listGorootMergeLinks(goroot, tinygoroot string, overrides map[string]bool)
 // with the TinyGo version. This is the case on some targets.
 func needsSyscallPackage(buildTags []string) bool {
 	for _, tag := range buildTags {
-		if tag == "baremetal" || tag == "darwin" || tag == "nintendoswitch" || tag == "tinygo.wasm" {
+		if tag == "baremetal" || tag == "nintendoswitch" || tag == "tinygo.wasm" {
 			return true
 		}
 	}
@@ -229,30 +229,34 @@ func needsSyscallPackage(buildTags []string) bool {
 // means use the TinyGo version.
 func pathsToOverride(goMinor int, needsSyscallPackage bool) map[string]bool {
 	paths := map[string]bool{
-		"":                      true,
-		"crypto/":               true,
-		"crypto/rand/":          false,
-		"crypto/tls/":           false,
-		"device/":               false,
-		"examples/":             false,
-		"internal/":             true,
-		"internal/abi/":         false,
-		"internal/binary/":      false,
-		"internal/bytealg/":     false,
-		"internal/cm/":          false,
-		"internal/fuzz/":        false,
-		"internal/reflectlite/": false,
-		"internal/task/":        false,
-		"internal/wasi/":        false,
-		"machine/":              false,
-		"net/":                  true,
-		"net/http/":             false,
-		"os/":                   true,
-		"reflect/":              false,
-		"runtime/":              false,
-		"sync/":                 true,
-		"testing/":              true,
-		"unique/":               false,
+		"":                            true,
+		"crypto/":                     true,
+		"crypto/rand/":                false,
+		"crypto/tls/":                 false,
+		"crypto/x509/":                true,
+		"crypto/x509/internal/":       true,
+		"crypto/x509/internal/macos/": false,
+		"device/":                     false,
+		"examples/":                   false,
+		"internal/":                   true,
+		"internal/abi/":               false,
+		"internal/binary/":            false,
+		"internal/bytealg/":           false,
+		"internal/cm/":                false,
+		"internal/fuzz/":              false,
+		"internal/reflectlite/":       false,
+		"internal/gclayout":           false,
+		"internal/task/":              false,
+		"internal/wasi/":              false,
+		"machine/":                    false,
+		"net/":                        true,
+		"net/http/":                   false,
+		"os/":                         true,
+		"reflect/":                    false,
+		"runtime/":                    false,
+		"sync/":                       true,
+		"testing/":                    true,
+		"unique/":                     false,
 	}
 
 	if goMinor >= 19 {

loader/loader.go

@@ -418,8 +418,12 @@ func (p *Package) Check() error {
 	packageName := p.ImportPath
 	if p == p.program.MainPkg() {
 		if p.Name != "main" {
-			// Sanity check. Should not ever trigger.
-			panic("expected main package to have name 'main'")
+			return Errors{p, []error{
+				scanner.Error{
+					Pos: p.program.fset.Position(p.Files[0].Name.Pos()),
+					Msg: fmt.Sprintf("expected main package to have name \"main\", not %#v", p.Name),
+				},
+			}}
 		}
 		packageName = "main"
 	}
@@ -428,7 +432,15 @@ func (p *Package) Check() error {
 		if err, ok := err.(Errors); ok {
 			return err
 		}
-		return Errors{p, typeErrors}
+		if len(typeErrors) != 0 {
+			// Got type errors, so return them.
+			return Errors{p, typeErrors}
+		}
+		// This can happen in some weird cases.
+		// The only case I know is when compiling a Go 1.23 program, with a
+		// TinyGo version that supports Go 1.23 but is compiled using Go 1.22.
+		// So this should be pretty rare.
+		return Errors{p, []error{err}}
 	}
 	p.Pkg = typesPkg
 

main.go

@@ -283,46 +283,6 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 		// Tests are always run in the package directory.
 		cmd.Dir = result.MainDir
 
-		// wasmtime is the default emulator used for `-target=wasip1`. wasmtime
-		// is a WebAssembly runtime CLI with WASI enabled by default. However,
-		// only stdio are allowed by default. For example, while STDOUT routes
-		// to the host, other files don't. It also does not inherit environment
-		// variables from the host. Some tests read testdata files, often from
-		// outside the package directory. Other tests require temporary
-		// writeable directories. We allow this by adding wasmtime flags below.
-		if config.EmulatorName() == "wasmtime" {
-			// At this point, The current working directory is at the package
-			// directory. Ex. $GOROOT/src/compress/flate for compress/flate.
-			// buildAndRun has already added arguments for wasmtime, that allow
-			// read-access to files such as "testdata/huffman-zero.in".
-			//
-			// Ex. main(.wasm) --dir=. -- -test.v
-
-			// Below adds additional wasmtime flags in case a test reads files
-			// outside its directory, like "../testdata/e.txt". This allows any
-			// relative directory up to the module root, even if the test never
-			// reads any files.
-			//
-			// Ex. run --dir=.. --dir=../.. --dir=../../..
-			var dirs []string
-			switch config.Target.GOOS {
-			case "wasip1":
-				dirs = dirsToModuleRootRel(result.MainDir, result.ModuleRoot)
-			default:
-				dirs = dirsToModuleRootAbs(result.MainDir, result.ModuleRoot)
-			}
-
-			args := []string{"run"}
-			for _, d := range dirs {
-				args = append(args, "--dir="+d)
-			}
-
-			args = append(args, "--env=PWD="+cmd.Dir)
-
-			args = append(args, cmd.Args[1:]...)
-			cmd.Args = args
-		}
-
 		// Run the test.
 		start := time.Now()
 		err = cmd.Run()
@@ -809,22 +769,18 @@ func Run(pkgName string, options *compileopts.Options, cmdArgs []string) error {
 // passes command line arguments and environment variables in a way appropriate
 // for the given emulator.
 func buildAndRun(pkgName string, config *compileopts.Config, stdout io.Writer, cmdArgs, environmentVars []string, timeout time.Duration, run func(cmd *exec.Cmd, result builder.BuildResult) error) (builder.BuildResult, error) {
-
-	isSingleFile := strings.HasSuffix(pkgName, ".go")
-
 	// Determine whether we're on a system that supports environment variables
-	// and command line parameters (operating systems, WASI) or not (baremetal,
-	// WebAssembly in the browser). If we're on a system without an environment,
-	// we need to pass command line arguments and environment variables through
-	// global variables (built into the binary directly) instead of the
-	// conventional way.
-	needsEnvInVars := config.GOOS() == "js"
+	// and command line parameters (operating systems, WASI) or not (baremetal).
+	// If we're on a system without an environment, we need to pass command line
+	// arguments and environment variables through global variables (built into
+	// the binary directly) instead of the conventional way.
+	needsEnvInVars := false
 	for _, tag := range config.BuildTags() {
 		if tag == "baremetal" {
 			needsEnvInVars = true
 		}
 	}
-	var args, emuArgs, env []string
+	var args, env []string
 	var extraCmdEnv []string
 	if needsEnvInVars {
 		runtimeGlobals := make(map[string]string)
@@ -844,21 +800,6 @@ func buildAndRun(pkgName string, config *compileopts.Config, stdout io.Writer, c
 				"runtime": runtimeGlobals,
 			}
 		}
-	} else if config.EmulatorName() == "wasmtime" {
-		for _, v := range environmentVars {
-			emuArgs = append(emuArgs, "--env", v)
-		}
-		if len(cmdArgs) != 0 {
-			// Use of '--' argument no longer necessary as of Wasmtime v14:
-			// https://github.com/bytecodealliance/wasmtime/pull/6946
-			// args = append(args, "--")
-			args = append(args, cmdArgs...)
-		}
-
-		// Set this for nicer backtraces during tests, but don't override the user.
-		if _, ok := os.LookupEnv("WASMTIME_BACKTRACE_DETAILS"); !ok {
-			extraCmdEnv = append(extraCmdEnv, "WASMTIME_BACKTRACE_DETAILS=1")
-		}
 	} else {
 		// Pass environment variables and command line parameters as usual.
 		// This also works on qemu-aarch64 etc.
@@ -901,27 +842,61 @@ func buildAndRun(pkgName string, config *compileopts.Config, stdout io.Writer, c
 			return result, err
 		}
 
-		name = emulator[0]
+		name, emulator = emulator[0], emulator[1:]
 
+		// wasmtime is a WebAssembly runtime CLI with WASI enabled by default.
+		// By default, only stdio is allowed. For example, while STDOUT routes
+		// to the host, other files don't. It also does not inherit environment
+		// variables from the host. Some tests read testdata files, often from
+		// outside the package directory. Other tests require temporary
+		// writeable directories. We allow this by adding wasmtime flags below.
 		if name == "wasmtime" {
-			// Wasmtime needs some special flags to pass environment variables
-			// and allow reading from the current directory.
-			switch config.Options.Target {
-			case "wasip1":
-				emuArgs = append(emuArgs, "--dir=.")
-			case "wasip2":
-				dir := result.MainDir
-				if isSingleFile {
-					cwd, _ := os.Getwd()
-					dir = cwd
-				}
-				emuArgs = append(emuArgs, "--dir="+dir)
-				emuArgs = append(emuArgs, "--env=PWD="+dir)
+			var emuArgs []string
+
+			// Extract the wasmtime subcommand (e.g. "run" or "serve")
+			if len(emulator) > 1 {
+				emuArgs = append(emuArgs, emulator[0])
+				emulator = emulator[1:]
 			}
+
+			wd, _ := os.Getwd()
+
+			// Below adds additional wasmtime flags in case a test reads files
+			// outside its directory, like "../testdata/e.txt". This allows any
+			// relative directory up to the module root, even if the test never
+			// reads any files.
+			if config.TestConfig.CompileTestBinary {
+				// Set working directory to package dir
+				wd = result.MainDir
+
+				// Add relative dirs (../, ../..) up to module root (for wasip1)
+				dirs := dirsToModuleRootRel(result.MainDir, result.ModuleRoot)
+
+				// Add absolute dirs up to module root (for wasip2)
+				dirs = append(dirs, dirsToModuleRootAbs(result.MainDir, result.ModuleRoot)...)
+
+				for _, d := range dirs {
+					emuArgs = append(emuArgs, "--dir="+d)
+				}
+			} else {
+				emuArgs = append(emuArgs, "--dir=.")
+			}
+
+			emuArgs = append(emuArgs, "--dir="+wd)
+			emuArgs = append(emuArgs, "--env=PWD="+wd)
+			for _, v := range environmentVars {
+				emuArgs = append(emuArgs, "--env", v)
+			}
+
+			// Set this for nicer backtraces during tests, but don't override the user.
+			if _, ok := os.LookupEnv("WASMTIME_BACKTRACE_DETAILS"); !ok {
+				extraCmdEnv = append(extraCmdEnv, "WASMTIME_BACKTRACE_DETAILS=1")
+			}
+
+			emulator = append(emuArgs, emulator...)
 		}
 
-		emuArgs = append(emuArgs, emulator[1:]...)
-		args = append(emuArgs, args...)
+		args = append(emulator, args...)
 	}
 	var cmd *exec.Cmd
 	if ctx != nil {
@@ -951,7 +926,7 @@ func buildAndRun(pkgName string, config *compileopts.Config, stdout io.Writer, c
 
 	// Run binary.
 	if config.Options.PrintCommands != nil {
-		config.Options.PrintCommands(cmd.Path, cmd.Args...)
+		config.Options.PrintCommands(cmd.Path, cmd.Args[1:]...)
 	}
 	err = run(cmd, result)
 	if err != nil {
@@ -1256,36 +1231,169 @@ func getBMPPorts() (gdbPort, uartPort string, err error) {
 	}
 }
 
-func usage(command string) {
-	switch command {
-	default:
-		fmt.Fprintln(os.Stderr, "TinyGo is a Go compiler for small places.")
-		fmt.Fprintln(os.Stderr, "version:", goenv.Version())
-		fmt.Fprintf(os.Stderr, "usage: %s <command> [arguments]\n", os.Args[0])
-		fmt.Fprintln(os.Stderr, "\ncommands:")
-		fmt.Fprintln(os.Stderr, "  build:   compile packages and dependencies")
-		fmt.Fprintln(os.Stderr, "  run:     compile and run immediately")
-		fmt.Fprintln(os.Stderr, "  test:    test packages")
-		fmt.Fprintln(os.Stderr, "  flash:   compile and flash to the device")
-		fmt.Fprintln(os.Stderr, "  gdb:     run/flash and immediately enter GDB")
-		fmt.Fprintln(os.Stderr, "  lldb:    run/flash and immediately enter LLDB")
-		fmt.Fprintln(os.Stderr, "  monitor: open communication port")
-		fmt.Fprintln(os.Stderr, "  ports:   list available serial ports")
-		fmt.Fprintln(os.Stderr, "  env:     list environment variables used during build")
-		fmt.Fprintln(os.Stderr, "  list:    run go list using the TinyGo root")
-		fmt.Fprintln(os.Stderr, "  clean:   empty cache directory ("+goenv.Get("GOCACHE")+")")
-		fmt.Fprintln(os.Stderr, "  targets: list targets")
-		fmt.Fprintln(os.Stderr, "  info:    show info for specified target")
-		fmt.Fprintln(os.Stderr, "  version: show version")
-		fmt.Fprintln(os.Stderr, "  help:    print this help text")
+const (
+	usageBuild = `Build compiles the packages named by the import paths, along with their
+dependencies, but it does not install the results. The output binary is
+specified using the -o parameter. The generated file type depends on the
+extension:
 
+	.o:
+			Create a relocatable object file. You can use this option if you
+			don't want to use the TinyGo build system or want to do other custom
+			things.
+
+	.ll:
+			Create textual LLVM IR, after optimization. This is mainly useful
+			for debugging.
+
+	.bc:
+			Create LLVM bitcode, after optimization. This may be useful for
+			debugging or for linking into other programs using LTO.
+
+	.hex:
+			Create an Intel HEX file to flash it to a microcontroller.
+
+	.bin:
+			Similar, but create a binary file.
+
+	.wasm:
+			Compile and link a WebAssembly file.
+
+(all other) Compile and link the program into a regular executable. For
+microcontrollers, it is common to use the .elf file extension to indicate a
+linked ELF file is generated. For Linux, it is common to build binaries with no
+extension at all.`
+
+	usageRun = `Run the program, either directly on the host or in an emulated environment 
+(depending on -target).`
+
+	usageFlash = `Flash the program to a microcontroller. Some common flags are described below.
+
+	-target={name}: 
+			Specifies the type of microcontroller that is used. The name of the
+			microcontroller is given on the individual pages for each board type
+			listed under Microcontrollers
+			(https://tinygo.org/docs/reference/microcontrollers/).
+			Examples: "arduino-nano", "d1mini", "xiao".
+
+	-monitor: 
+			Start the serial monitor (see below) immediately after
+			flashing. However, some microcontrollers need a split second
+			or two to configure the serial port after flashing, and
+			using the "-monitor" flag can fail because the serial
+			monitor starts too quickly. In that case, use the "tinygo
+			monitor" command explicitly.`
+
+	usageMonitor = `Start the serial monitor on the serial port that is connected to the
+microcontroller. If there is only a single board attached to the host computer,
+the default values for various options should be sufficient. In other
+situations, particularly if you have multiple microcontrollers attached, some
+parameters may need to be overridden using the following flags:
+
+	-port={port}:
+			If there are multiple microcontroller attached, an error
+			message will display a list of potential serial ports. The
+			appropriate port can be specified by this flag. On Linux,
+			the port will be something like /dev/ttyUSB0 or /dev/ttyACM1.
+			On MacOS, the port will look like /dev/cu.usbserial-1420. On
+			Windows, the port will be something like COM1 or COM31.
+
+	-baudrate={rate}:
+			The default baud rate is 115200. Boards using the AVR
+			processor (e.g. Arduino Nano, Arduino Mega 2560) use 9600
+			instead.
+
+	-target={name}:
+			If you have more than one microcontrollers attached, you can
+			sometimes just specify the target name and let tinygo
+			monitor figure out the port. Sometimes, this does not work
+			and you have to explicitly use the -port flag.
+
+The serial monitor intercepts several control characters for its own use instead of sending them
+to the microcontroller:
+
+	Control-C: terminates the tinygo monitor
+	Control-Z: suspends the tinygo monitor and drops back into shell
+	Control-\: terminates the tinygo monitor with a stack trace
+	Control-S: flow control, suspends output to the console
+	Control-Q: flow control, resumes output to the console
+	Control-@: thrown away by tinygo monitor
+
+Note: If you are using os.Stdin on the microcontroller, you may find that a CR
+character on the host computer (also known as Enter, ^M, or \r) is transmitted
+to the microcontroller without conversion, so os.Stdin returns a \r character
+instead of the expected \n (also known as ^J, NL, or LF) to indicate
+end-of-line. You may be able to get around this problem by hitting Control-J in
+tinygo monitor to transmit the \n end-of-line character.`
+
+	usageGdb = `Build the program, optionally flash it to a microcontroller if it is a remote 
+target, and drop into a GDB shell. From there you can set breakpoints, start the
+program with "run" or "continue" ("run" for a local program, continue for
+on-chip debugging), single-step, show a backtrace, break and resume the program
+with Ctrl-C/"continue", etc. You may need to install extra tools (like openocd
+and arm-none-eabi-gdb) to be able to do this. Also, you may need a dedicated
+debugger to be able to debug certain boards if no debugger is integrated. Some
+boards (like the BBC micro:bit and most professional evaluation boards) have an
+integrated debugger.`
+
+	usageClean = `Clean the cache directory, normally stored in $HOME/.cache/tinygo. This is not
+normally needed.`
+
+	usageHelp    = `Print a short summary of the available commands, plus a list of command flags.`
+	usageVersion = `Print the version of the command and the version of the used $GOROOT.`
+	usageEnv     = `Print a list of environment variables that affect TinyGo (as a shell script).
+If one or more variable names are given as arguments, env prints the value of
+each on a new line.`
+
+	usageDefault = `TinyGo is a Go compiler for small places.
+version: %s
+usage: %s <command> [arguments]
+commands:
+		build:		compile packages and dependencies
+		run:		compile and run immediately
+		test:		test packages
+		flash:		compile and flash to the device
+		gdb:		run/flash and immediately enter GDB
+		lldb:		run/flash and immediately enter LLDB
+		monitor:	open communication port
+		ports:		list available serial ports
+		env:		list environment variables used during build
+		list:		run go list using the TinyGo root
+		clean:		empty cache directory (%s)
+		targets:	list targets
+		info:		show info for specified target
+		version:	show version
+		help:		print this help text`
+)
+
+var (
+	commandHelp = map[string]string{
+		"build":   usageBuild,
+		"run":     usageRun,
+		"flash":   usageFlash,
+		"monitor": usageMonitor,
+		"gdb":     usageGdb,
+		"clean":   usageClean,
+		"help":    usageHelp,
+		"version": usageVersion,
+		"env":     usageEnv,
+	}
+)
+
+func usage(command string) {
+	val, ok := commandHelp[command]
+	if !ok {
+		fmt.Fprintf(os.Stderr, usageDefault, goenv.Version(), os.Args[0], goenv.Get("GOCACHE"))
 		if flag.Parsed() {
 			fmt.Fprintln(os.Stderr, "\nflags:")
 			flag.PrintDefaults()
 		}
 
 		fmt.Fprintln(os.Stderr, "\nfor more details, see https://tinygo.org/docs/reference/usage/")
+	} else {
+		fmt.Fprintln(os.Stderr, val)
 	}
+
 }
 
 func handleCompilerError(err error) {
@@ -1330,19 +1438,20 @@ func (m globalValuesFlag) Set(value string) error {
 
 // parseGoLinkFlag parses the -ldflags parameter. Its primary purpose right now
 // is the -X flag, for setting the value of global string variables.
-func parseGoLinkFlag(flagsString string) (map[string]map[string]string, error) {
+func parseGoLinkFlag(flagsString string) (map[string]map[string]string, string, error) {
 	set := flag.NewFlagSet("link", flag.ExitOnError)
 	globalVarValues := make(globalValuesFlag)
 	set.Var(globalVarValues, "X", "Set the value of the string variable to the given value.")
+	extLDFlags := set.String("extldflags", "", "additional flags to pass to external linker")
 	flags, err := shlex.Split(flagsString)
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
 	err = set.Parse(flags)
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
-	return map[string]map[string]string(globalVarValues), nil
+	return map[string]map[string]string(globalVarValues), *extLDFlags, nil
 }
 
 // getListOfPackages returns a standard list of packages for a given list that might
@@ -1392,6 +1501,7 @@ func main() {
 	var tags buildutil.TagsFlag
 	flag.Var(&tags, "tags", "a space-separated list of extra build tags")
 	target := flag.String("target", "", "chip/board name or JSON target specification file")
+	buildMode := flag.String("buildmode", "", "build mode to use (default, c-shared)")
 	var stackSize uint64
 	flag.Func("stack-size", "goroutine stack size (if unknown at compile time)", func(s string) error {
 		size, err := bytesize.Parse(s)
@@ -1461,6 +1571,7 @@ func main() {
 
 	// Early command processing, before commands are interpreted by the Go flag
 	// library.
+	handleChdirFlag()
 	switch command {
 	case "clang", "ld.lld", "wasm-ld":
 		err := builder.RunTool(command, os.Args[2:]...)
@@ -1473,7 +1584,7 @@ func main() {
 	}
 
 	flag.CommandLine.Parse(os.Args[2:])
-	globalVarValues, err := parseGoLinkFlag(*ldflags)
+	globalVarValues, extLDFlags, err := parseGoLinkFlag(*ldflags)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
@@ -1499,6 +1610,7 @@ func main() {
 		GOARM:           goenv.Get("GOARM"),
 		GOMIPS:          goenv.Get("GOMIPS"),
 		Target:          *target,
+		BuildMode:       *buildMode,
 		StackSize:       stackSize,
 		Opt:             *opt,
 		GC:              *gc,
@@ -1528,6 +1640,7 @@ func main() {
 		Timeout:         *timeout,
 		WITPackage:      witPackage,
 		WITWorld:        witWorld,
+		ExtLDFlags:      extLDFlags,
 	}
 	if *printCommands {
 		options.PrintCommands = printCommand
@@ -1946,3 +2059,56 @@ type outputEntry struct {
 	stderr bool
 	data   []byte
 }
+
+// handleChdirFlag handles the -C flag before doing anything else.
+// The -C flag must be the first flag on the command line, to make it easy to find
+// even with commands that have custom flag parsing.
+// handleChdirFlag handles the flag by chdir'ing to the directory
+// and then removing that flag from the command line entirely.
+//
+// We have to handle the -C flag this way for two reasons:
+//
+//  1. Toolchain selection needs to be in the right directory to look for go.mod and go.work.
+//
+//  2. A toolchain switch later on reinvokes the new go command with the same arguments.
+//     The parent toolchain has already done the chdir; the child must not try to do it again.
+
+func handleChdirFlag() {
+	used := 2 // b.c. command at os.Args[1]
+	if used >= len(os.Args) {
+		return
+	}
+
+	var dir string
+	switch a := os.Args[used]; {
+	default:
+		return
+
+	case a == "-C", a == "--C":
+		if used+1 >= len(os.Args) {
+			return
+		}
+		dir = os.Args[used+1]
+		os.Args = slicesDelete(os.Args, used, used+2)
+
+	case strings.HasPrefix(a, "-C="), strings.HasPrefix(a, "--C="):
+		_, dir, _ = strings.Cut(a, "=")
+		os.Args = slicesDelete(os.Args, used, used+1)
+	}
+
+	if err := os.Chdir(dir); err != nil {
+		fmt.Fprintln(os.Stderr, "cannot chdir:", err)
+		os.Exit(1)
+	}
+}
+
+// go1.19 compatibility: lacks slices package
+func slicesDelete[S ~[]E, E any](s S, i, j int) S {
+	_ = s[i:j:len(s)] // bounds check
+
+	if i == j {
+		return s
+	}
+
+	return append(s[:i], s[j:]...)
+}

main_test.go

@@ -6,6 +6,7 @@ package main
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"errors"
 	"flag"
 	"io"
@@ -21,6 +22,9 @@ import (
 	"time"
 
 	"github.com/aykevl/go-wasm"
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/api"
+	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
 	"github.com/tinygo-org/tinygo/builder"
 	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/diagnostics"
@@ -36,7 +40,7 @@ var supportedLinuxArches = map[string]string{
 	"X86Linux":   "linux/386",
 	"ARMLinux":   "linux/arm/6",
 	"ARM64Linux": "linux/arm64",
-	"MIPSLinux":  "linux/mipsle/hardfloat",
+	"MIPSLinux":  "linux/mips/hardfloat",
 	"WASIp1":     "wasip1/wasm",
 }
 
@@ -75,6 +79,7 @@ func TestBuild(t *testing.T) {
 		"oldgo/",
 		"print.go",
 		"reflect.go",
+		"signal.go",
 		"slice.go",
 		"sort.go",
 		"stdlib.go",
@@ -177,13 +182,14 @@ func TestBuild(t *testing.T) {
 				})
 			}
 		}
-		t.Run("MIPS big-endian", func(t *testing.T) {
-			// Run a single test for GOARCH=mips to see whether it works at all.
-			// Big-endian MIPS isn't fully supported yet, but simple examples
-			// should work.
+		t.Run("MIPS little-endian", func(t *testing.T) {
+			// Run a single test for GOARCH=mipsle to see whether it works at
+			// all. It is already mostly tested because GOARCH=mips and
+			// GOARCH=mipsle are so similar, but it's good to have an extra test
+			// to be sure.
 			t.Parallel()
-			options := optionsFromOSARCH("linux/mips/softfloat", sema)
-			runTest("alias.go", options, t, nil, nil)
+			options := optionsFromOSARCH("linux/mipsle/softfloat", sema)
+			runTest("cgo/", options, t, nil, nil)
 		})
 		t.Run("WebAssembly", func(t *testing.T) {
 			t.Parallel()
@@ -212,6 +218,7 @@ func runPlatTests(options compileopts.Options, tests []string, t *testing.T) {
 	// isWebAssembly := strings.HasPrefix(spec.Triple, "wasm")
 	isWASI := strings.HasPrefix(options.Target, "wasi")
 	isWebAssembly := isWASI || strings.HasPrefix(options.Target, "wasm") || (options.Target == "" && strings.HasPrefix(options.GOARCH, "wasm"))
+	isBaremetal := options.Target == "simavr" || options.Target == "cortex-m-qemu" || options.Target == "riscv-qemu"
 
 	for _, name := range tests {
 		if options.GOOS == "linux" && (options.GOARCH == "arm" || options.GOARCH == "386") {
@@ -228,6 +235,13 @@ func runPlatTests(options compileopts.Options, tests []string, t *testing.T) {
 				continue
 			}
 		}
+		if options.GOOS == "linux" && options.GOARCH == "mips" {
+			if name == "cgo/" {
+				// CGo isn't supported yet on big-endian systems (needs updates
+				// to bitfield access methods).
+				continue
+			}
+		}
 		if options.Target == "simavr" {
 			// Not all tests are currently supported on AVR.
 			// Skip the ones that aren't.
@@ -269,6 +283,13 @@ func runPlatTests(options compileopts.Options, tests []string, t *testing.T) {
 				continue
 			}
 		}
+		if isWebAssembly || isBaremetal || options.GOOS == "windows" {
+			switch name {
+			case "signal.go":
+				// Signals only work on POSIX-like systems.
+				continue
+			}
+		}
 
 		name := name // redefine to avoid race condition
 		t.Run(name, func(t *testing.T) {
@@ -384,17 +405,13 @@ func runTestWithConfig(name string, t *testing.T, options compileopts.Options, c
 	// of the path.
 	path := TESTDATA + "/" + name
 	// Get the expected output for this test.
-	txtpath := path[:len(path)-3] + ".txt"
+	expectedOutputPath := path[:len(path)-3] + ".txt"
 	pkgName := "./" + path
 	if path[len(path)-1] == '/' {
-		txtpath = path + "out.txt"
+		expectedOutputPath = path + "out.txt"
 		options.Directory = path
 		pkgName = "."
 	}
-	expected, err := os.ReadFile(txtpath)
-	if err != nil {
-		t.Fatal("could not read expected output file:", err)
-	}
 
 	config, err := builder.NewConfig(&options)
 	if err != nil {
@@ -416,10 +433,7 @@ func runTestWithConfig(name string, t *testing.T, options compileopts.Options, c
 		return
 	}
 
-	// putchar() prints CRLF, convert it to LF.
-	actual := bytes.Replace(stdout.Bytes(), []byte{'\r', '\n'}, []byte{'\n'}, -1)
-	expected = bytes.Replace(expected, []byte{'\r', '\n'}, []byte{'\n'}, -1) // for Windows
-
+	actual := stdout.Bytes()
 	if config.EmulatorName() == "simavr" {
 		// Strip simavr log formatting.
 		actual = bytes.Replace(actual, []byte{0x1b, '[', '3', '2', 'm'}, nil, -1)
@@ -434,17 +448,12 @@ func runTestWithConfig(name string, t *testing.T, options compileopts.Options, c
 	}
 
 	// Check whether the command ran successfully.
-	fail := false
 	if err != nil {
-		t.Log("failed to run:", err)
-		fail = true
-	} else if !bytes.Equal(expected, actual) {
-		t.Logf("output did not match (expected %d bytes, got %d bytes):", len(expected), len(actual))
-		t.Logf(string(Diff("expected", expected, "actual", actual)))
-		fail = true
+		t.Error("failed to run:", err)
 	}
+	checkOutput(t, expectedOutputPath, actual)
 
-	if fail {
+	if t.Failed() {
 		r := bufio.NewReader(bytes.NewReader(actual))
 		for {
 			line, err := r.ReadString('\n')
@@ -462,20 +471,21 @@ func TestWebAssembly(t *testing.T) {
 	t.Parallel()
 	type testCase struct {
 		name          string
+		target        string
 		panicStrategy string
 		imports       []string
 	}
 	for _, tc := range []testCase{
 		// Test whether there really are no imports when using -panic=trap. This
 		// tests the bugfix for https://github.com/tinygo-org/tinygo/issues/4161.
-		{name: "panic-default", imports: []string{"wasi_snapshot_preview1.fd_write"}},
-		{name: "panic-trap", panicStrategy: "trap", imports: []string{}},
+		{name: "panic-default", target: "wasip1", imports: []string{"wasi_snapshot_preview1.fd_write", "wasi_snapshot_preview1.random_get"}},
+		{name: "panic-trap", target: "wasm-unknown", panicStrategy: "trap", imports: []string{}},
 	} {
 		tc := tc
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
 			tmpdir := t.TempDir()
-			options := optionsFromTarget("wasi", sema)
+			options := optionsFromTarget(tc.target, sema)
 			options.PanicStrategy = tc.panicStrategy
 			config, err := builder.NewConfig(&options)
 			if err != nil {
@@ -515,6 +525,262 @@ func TestWebAssembly(t *testing.T) {
 	}
 }
 
+func TestWasmExport(t *testing.T) {
+	t.Parallel()
+
+	type testCase struct {
+		name      string
+		target    string
+		buildMode string
+		scheduler string
+		file      string
+		noOutput  bool
+		command   bool // call _start (command mode) instead of _initialize
+	}
+
+	tests := []testCase{
+		// "command mode" WASI
+		{
+			name:    "WASIp1-command",
+			target:  "wasip1",
+			command: true,
+		},
+		// "reactor mode" WASI (with -buildmode=c-shared)
+		{
+			name:      "WASIp1-reactor",
+			target:    "wasip1",
+			buildMode: "c-shared",
+		},
+		// Make sure reactor mode also works without a scheduler.
+		{
+			name:      "WASIp1-reactor-noscheduler",
+			target:    "wasip1",
+			buildMode: "c-shared",
+			scheduler: "none",
+			file:      "wasmexport-noscheduler.go",
+		},
+		// Test -target=wasm-unknown with the default build mode (which is
+		// c-shared).
+		{
+			name:     "wasm-unknown-reactor",
+			target:   "wasm-unknown",
+			file:     "wasmexport-noscheduler.go",
+			noOutput: true, // wasm-unknown cannot produce output
+		},
+		// Test -target=wasm-unknown with -buildmode=default, which makes it run
+		// in command mode.
+		{
+			name:      "wasm-unknown-command",
+			target:    "wasm-unknown",
+			buildMode: "default",
+			file:      "wasmexport-noscheduler.go",
+			noOutput:  true, // wasm-unknown cannot produce output
+			command:   true,
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			// Build the wasm binary.
+			tmpdir := t.TempDir()
+			options := optionsFromTarget(tc.target, sema)
+			options.BuildMode = tc.buildMode
+			options.Scheduler = tc.scheduler
+			buildConfig, err := builder.NewConfig(&options)
+			if err != nil {
+				t.Fatal(err)
+			}
+			filename := "wasmexport.go"
+			if tc.file != "" {
+				filename = tc.file
+			}
+			result, err := builder.Build("testdata/"+filename, ".wasm", tmpdir, buildConfig)
+			if err != nil {
+				t.Fatal("failed to build binary:", err)
+			}
+
+			// Read the wasm binary back into memory.
+			data, err := os.ReadFile(result.Binary)
+			if err != nil {
+				t.Fatal("could not read wasm binary: ", err)
+			}
+
+			// Set up the wazero runtime.
+			output := &bytes.Buffer{}
+			ctx := context.Background()
+			r := wazero.NewRuntimeWithConfig(ctx, wazero.NewRuntimeConfigInterpreter())
+			defer r.Close(ctx)
+			config := wazero.NewModuleConfig().
+				WithStdout(output).WithStderr(output).
+				WithStartFunctions()
+
+			// Prepare for testing.
+			var mod api.Module
+			mustCall := func(results []uint64, err error) []uint64 {
+				if err != nil {
+					t.Error("failed to run function:", err)
+				}
+				return results
+			}
+			checkResult := func(name string, results []uint64, expected []uint64) {
+				if len(results) != len(expected) {
+					t.Errorf("%s: expected %v but got %v", name, expected, results)
+				}
+				for i, result := range results {
+					if result != expected[i] {
+						t.Errorf("%s: expected %v but got %v", name, expected, results)
+						break
+					}
+				}
+			}
+			runTests := func() {
+				// Test an exported function without params or return value.
+				checkResult("hello()", mustCall(mod.ExportedFunction("hello").Call(ctx)), nil)
+
+				// Test that we can call an exported function more than once.
+				checkResult("add(3, 5)", mustCall(mod.ExportedFunction("add").Call(ctx, 3, 5)), []uint64{8})
+				checkResult("add(7, 9)", mustCall(mod.ExportedFunction("add").Call(ctx, 7, 9)), []uint64{16})
+				checkResult("add(6, 1)", mustCall(mod.ExportedFunction("add").Call(ctx, 6, 1)), []uint64{7})
+
+				// Test that imported functions can call exported functions
+				// again.
+				checkResult("reentrantCall(2, 3)", mustCall(mod.ExportedFunction("reentrantCall").Call(ctx, 2, 3)), []uint64{5})
+				checkResult("reentrantCall(1, 8)", mustCall(mod.ExportedFunction("reentrantCall").Call(ctx, 1, 8)), []uint64{9})
+			}
+
+			// Add wasip1 module.
+			wasi_snapshot_preview1.MustInstantiate(ctx, r)
+
+			// Add custom "tester" module.
+			callOutside := func(a, b int32) int32 {
+				results, err := mod.ExportedFunction("add").Call(ctx, uint64(a), uint64(b))
+				if err != nil {
+					t.Error("could not call exported add function:", err)
+				}
+				return int32(results[0])
+			}
+			callTestMain := func() {
+				runTests()
+			}
+			builder := r.NewHostModuleBuilder("tester")
+			builder.NewFunctionBuilder().WithFunc(callOutside).Export("callOutside")
+			builder.NewFunctionBuilder().WithFunc(callTestMain).Export("callTestMain")
+			_, err = builder.Instantiate(ctx)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			// Parse and instantiate the wasm.
+			mod, err = r.InstantiateWithConfig(ctx, data, config)
+			if err != nil {
+				t.Fatal("could not instantiate wasm module:", err)
+			}
+
+			// Initialize the module and run the tests.
+			if tc.command {
+				// Call _start (the entry point), which calls
+				// tester.callTestMain, which then runs all the tests.
+				mustCall(mod.ExportedFunction("_start").Call(ctx))
+			} else {
+				// Run the _initialize call, because this is reactor mode wasm.
+				mustCall(mod.ExportedFunction("_initialize").Call(ctx))
+				runTests()
+			}
+
+			// Check that the output matches the expected output.
+			// (Skip this for wasm-unknown because it can't produce output).
+			if !tc.noOutput {
+				checkOutput(t, "testdata/wasmexport.txt", output.Bytes())
+			}
+		})
+	}
+}
+
+// Test js.FuncOf (for syscall/js).
+// This test might be extended in the future to cover more cases in syscall/js.
+func TestWasmFuncOf(t *testing.T) {
+	// Build the wasm binary.
+	tmpdir := t.TempDir()
+	options := optionsFromTarget("wasm", sema)
+	buildConfig, err := builder.NewConfig(&options)
+	if err != nil {
+		t.Fatal(err)
+	}
+	result, err := builder.Build("testdata/wasmfunc.go", ".wasm", tmpdir, buildConfig)
+	if err != nil {
+		t.Fatal("failed to build binary:", err)
+	}
+
+	// Test the resulting binary using NodeJS.
+	output := &bytes.Buffer{}
+	cmd := exec.Command("node", "testdata/wasmfunc.js", result.Binary, buildConfig.BuildMode())
+	cmd.Stdout = output
+	cmd.Stderr = output
+	err = cmd.Run()
+	if err != nil {
+		t.Error("failed to run node:", err)
+	}
+	checkOutput(t, "testdata/wasmfunc.txt", output.Bytes())
+}
+
+// Test //go:wasmexport in JavaScript (using NodeJS).
+func TestWasmExportJS(t *testing.T) {
+	type testCase struct {
+		name      string
+		buildMode string
+	}
+
+	tests := []testCase{
+		{name: "default"},
+		{name: "c-shared", buildMode: "c-shared"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			// Build the wasm binary.
+			tmpdir := t.TempDir()
+			options := optionsFromTarget("wasm", sema)
+			options.BuildMode = tc.buildMode
+			buildConfig, err := builder.NewConfig(&options)
+			if err != nil {
+				t.Fatal(err)
+			}
+			result, err := builder.Build("testdata/wasmexport-noscheduler.go", ".wasm", tmpdir, buildConfig)
+			if err != nil {
+				t.Fatal("failed to build binary:", err)
+			}
+
+			// Test the resulting binary using NodeJS.
+			output := &bytes.Buffer{}
+			cmd := exec.Command("node", "testdata/wasmexport.js", result.Binary, buildConfig.BuildMode())
+			cmd.Stdout = output
+			cmd.Stderr = output
+			err = cmd.Run()
+			if err != nil {
+				t.Error("failed to run node:", err)
+			}
+			checkOutput(t, "testdata/wasmexport.txt", output.Bytes())
+		})
+	}
+}
+
+// Check whether the output of a test equals the expected output.
+func checkOutput(t *testing.T, filename string, actual []byte) {
+	expectedOutput, err := os.ReadFile(filename)
+	if err != nil {
+		t.Fatal("could not read output file:", err)
+	}
+	expectedOutput = bytes.ReplaceAll(expectedOutput, []byte("\r\n"), []byte("\n"))
+	actual = bytes.ReplaceAll(actual, []byte("\r\n"), []byte("\n"))
+
+	if !bytes.Equal(actual, expectedOutput) {
+		t.Errorf("output did not match (expected %d bytes, got %d bytes):", len(expectedOutput), len(actual))
+		t.Error(string(Diff("expected", expectedOutput, "actual", actual)))
+	}
+}
+
 func TestTest(t *testing.T) {
 	t.Parallel()
 

src/crypto/x509/internal/macos/macos.go

@@ -0,0 +1,185 @@
+package macos
+
+import (
+	"errors"
+	"time"
+)
+
+// Exported symbols copied from Big Go, but stripped of functionality.
+// Allows building of crypto/x509 on macOS.
+
+const (
+	ErrSecCertificateExpired = -67818
+	ErrSecHostNameMismatch   = -67602
+	ErrSecNotTrusted         = -67843
+)
+
+var ErrNoTrustSettings = errors.New("no trust settings found")
+var SecPolicyAppleSSL = StringToCFString("1.2.840.113635.100.1.3") // defined by POLICYMACRO
+var SecPolicyOid = StringToCFString("SecPolicyOid")
+var SecTrustSettingsPolicy = StringToCFString("kSecTrustSettingsPolicy")
+var SecTrustSettingsPolicyString = StringToCFString("kSecTrustSettingsPolicyString")
+var SecTrustSettingsResultKey = StringToCFString("kSecTrustSettingsResult")
+
+func CFArrayAppendValue(array CFRef, val CFRef) {}
+
+func CFArrayGetCount(array CFRef) int {
+	return 0
+}
+
+func CFDataGetBytePtr(data CFRef) uintptr {
+	return 0
+}
+
+func CFDataGetLength(data CFRef) int {
+	return 0
+}
+
+func CFDataToSlice(data CFRef) []byte {
+	return nil
+}
+
+func CFEqual(a, b CFRef) bool {
+	return false
+}
+
+func CFErrorGetCode(errRef CFRef) int {
+	return 0
+}
+
+func CFNumberGetValue(num CFRef) (int32, error) {
+	return 0, errors.New("not implemented")
+}
+
+func CFRelease(ref CFRef) {}
+
+func CFStringToString(ref CFRef) string {
+	return ""
+}
+
+func ReleaseCFArray(array CFRef) {}
+
+func SecCertificateCopyData(cert CFRef) ([]byte, error) {
+	return nil, errors.New("not implemented")
+}
+
+func SecTrustEvaluateWithError(trustObj CFRef) (int, error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecTrustGetCertificateCount(trustObj CFRef) int {
+	return 0
+}
+
+func SecTrustGetResult(trustObj CFRef, result CFRef) (CFRef, CFRef, error) {
+	return 0, 0, errors.New("not implemented")
+}
+
+func SecTrustSetVerifyDate(trustObj CFRef, dateRef CFRef) error {
+	return errors.New("not implemented")
+}
+
+type CFRef uintptr
+
+func BytesToCFData(b []byte) CFRef {
+	return 0
+}
+
+func CFArrayCreateMutable() CFRef {
+	return 0
+}
+
+func CFArrayGetValueAtIndex(array CFRef, index int) CFRef {
+	return 0
+}
+
+func CFDateCreate(seconds float64) CFRef {
+	return 0
+}
+
+func CFDictionaryGetValueIfPresent(dict CFRef, key CFString) (value CFRef, ok bool) {
+	return 0, false
+}
+
+func CFErrorCopyDescription(errRef CFRef) CFRef {
+	return 0
+}
+
+func CFStringCreateExternalRepresentation(strRef CFRef) (CFRef, error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecCertificateCreateWithData(b []byte) (CFRef, error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecPolicyCreateSSL(name string) (CFRef, error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecTrustCreateWithCertificates(certs CFRef, policies CFRef) (CFRef, error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecTrustEvaluate(trustObj CFRef) (CFRef, error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecTrustGetCertificateAtIndex(trustObj CFRef, i int) (CFRef, error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecTrustSettingsCopyCertificates(domain SecTrustSettingsDomain) (certArray CFRef, err error) {
+	return 0, errors.New("not implemented")
+}
+
+func SecTrustSettingsCopyTrustSettings(cert CFRef, domain SecTrustSettingsDomain) (trustSettings CFRef, err error) {
+	return 0, errors.New("not implemented")
+}
+
+func TimeToCFDateRef(t time.Time) CFRef {
+	return 0
+}
+
+type CFString CFRef
+
+func StringToCFString(s string) CFString {
+	return 0
+}
+
+type OSStatus struct {
+	// Has unexported fields.
+}
+
+func (s OSStatus) Error() string
+
+type SecTrustResultType int32
+
+const (
+	SecTrustResultInvalid SecTrustResultType = iota
+	SecTrustResultProceed
+	SecTrustResultConfirm // deprecated
+	SecTrustResultDeny
+	SecTrustResultUnspecified
+	SecTrustResultRecoverableTrustFailure
+	SecTrustResultFatalTrustFailure
+	SecTrustResultOtherError
+)
+
+type SecTrustSettingsDomain int32
+
+const (
+	SecTrustSettingsDomainUser SecTrustSettingsDomain = iota
+	SecTrustSettingsDomainAdmin
+	SecTrustSettingsDomainSystem
+)
+
+type SecTrustSettingsResult int32
+
+const (
+	SecTrustSettingsResultInvalid SecTrustSettingsResult = iota
+	SecTrustSettingsResultTrustRoot
+	SecTrustSettingsResultTrustAsRoot
+	SecTrustSettingsResultDeny
+	SecTrustSettingsResultUnspecified
+)

src/internal/abi/funcpc.go

@@ -4,11 +4,9 @@ package abi
 // (in particular internal/syscall/unix on MacOS). They do not currently have an
 // implementation, in part because TinyGo doesn't use ABI0 or ABIInternal (it
 // uses a C-like calling convention).
+// Calls to FuncPCABI0 however are treated specially by the compiler when
+// compiling for MacOS.
 
-func FuncPCABI0(f interface{}) uintptr {
-	panic("unimplemented: internal/abi.FuncPCABI0")
-}
+func FuncPCABI0(f interface{}) uintptr
 
-func FuncPCABIInternal(f interface{}) uintptr {
-	panic("unimplemented: internal/abi.FuncPCABIInternal")
-}
+func FuncPCABIInternal(f interface{}) uintptr

src/internal/binary/binary.go

@@ -30,3 +30,8 @@ func (littleEndian) AppendUint16(b []byte, v uint16) []byte {
 func (littleEndian) Uint32(b []byte) uint32 {
 	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
 }
+
+func (littleEndian) Uint64(b []byte) uint64 {
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}

src/internal/cm/abi.go

@@ -2,6 +2,11 @@ package cm
 
 import "unsafe"
 
+// AnyInteger is a type constraint for any integer type.
+type AnyInteger interface {
+	~int | ~uint | ~uintptr | ~int8 | ~uint8 | ~int16 | ~uint16 | ~int32 | ~uint32 | ~int64 | ~uint64
+}
+
 // Reinterpret reinterprets the bits of type From into type T.
 // Will panic if the size of From is smaller than the size of To.
 func Reinterpret[T, From any](from From) (to T) {
@@ -19,19 +24,19 @@ func LowerString[S ~string](s S) (*byte, uint32) {
 }
 
 // LiftString lifts Core WebAssembly types into a [string].
-func LiftString[T ~string, Data unsafe.Pointer | uintptr | *uint8, Len uint | uintptr | uint32 | uint64](data Data, len Len) T {
+func LiftString[T ~string, Data unsafe.Pointer | uintptr | *uint8, Len AnyInteger](data Data, len Len) T {
 	return T(unsafe.String((*uint8)(unsafe.Pointer(data)), int(len)))
 }
 
 // LowerList lowers a [List] into a pair of Core WebAssembly types.
-func LowerList[L ~struct{ list[T] }, T any](list L) (*T, uint32) {
+func LowerList[L AnyList[T], T any](list L) (*T, uint32) {
 	l := (*List[T])(unsafe.Pointer(&list))
 	return l.data, uint32(l.len)
 }
 
 // LiftList lifts Core WebAssembly types into a [List].
-func LiftList[L List[T], T any, Data unsafe.Pointer | uintptr | *T, Len uint | uintptr | uint32 | uint64](data Data, len Len) L {
-	return L(NewList((*T)(unsafe.Pointer(data)), uint(len)))
+func LiftList[L AnyList[T], T any, Data unsafe.Pointer | uintptr | *T, Len AnyInteger](data Data, len Len) L {
+	return L(NewList((*T)(unsafe.Pointer(data)), len))
 }
 
 // BoolToU32 converts a value whose underlying type is [bool] into a [uint32].
@@ -84,6 +89,25 @@ func F64ToU64(v float64) uint64 { return *(*uint64)(unsafe.Pointer(&v)) }
 // [Canonical ABI]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/CanonicalABI.md
 func U64ToF64(v uint64) float64 { return *(*float64)(unsafe.Pointer(&v)) }
 
+// F32ToU64 maps the bits of a [float32] into a [uint64].
+// Used to lower a [float32] into a Core WebAssembly i64 when required by the [Canonical ABI].
+//
+// [float32]: https://pkg.go.dev/builtin#float32
+// [uint64]: https://pkg.go.dev/builtin#uint64
+// [Canonical ABI]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/CanonicalABI.md
+func F32ToU64(v float32) uint64 { return uint64(*(*uint32)(unsafe.Pointer(&v))) }
+
+// U64ToF32 maps the bits of a [uint64] into a [float32].
+// Used to lift a Core WebAssembly i64 into a [float32] when required by the [Canonical ABI].
+//
+// [uint64]: https://pkg.go.dev/builtin#uint64
+// [float32]: https://pkg.go.dev/builtin#float32
+// [Canonical ABI]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/CanonicalABI.md
+func U64ToF32(v uint64) float32 {
+	truncated := uint32(v)
+	return *(*float32)(unsafe.Pointer(&truncated))
+}
+
 // PointerToU32 converts a pointer of type *T into a [uint32].
 // Used to lower a pointer into a Core WebAssembly i32 as specified in the [Canonical ABI].
 //

src/internal/cm/hostlayout_go122.go

@@ -0,0 +1,11 @@
+//go:build !go1.23
+
+package cm
+
+// HostLayout marks a struct as using host memory layout.
+// See [structs.HostLayout] in Go 1.23 or later.
+type HostLayout struct {
+	_ hostLayout // prevent accidental conversion with plain struct{}
+}
+
+type hostLayout struct{}

src/internal/cm/hostlayout_go123.go

@@ -0,0 +1,9 @@
+//go:build go1.23
+
+package cm
+
+import "structs"
+
+// HostLayout marks a struct as using host memory layout.
+// See [structs.HostLayout] in Go 1.23 or later.
+type HostLayout = structs.HostLayout

src/internal/cm/list.go

@@ -4,14 +4,25 @@ import "unsafe"
 
 // List represents a Component Model list.
 // The binary representation of list<T> is similar to a Go slice minus the cap field.
-type List[T any] struct{ list[T] }
+type List[T any] struct {
+	_ HostLayout
+	list[T]
+}
+
+// AnyList is a type constraint for generic functions that accept any [List] type.
+type AnyList[T any] interface {
+	~struct {
+		_ HostLayout
+		list[T]
+	}
+}
 
 // NewList returns a List[T] from data and len.
-func NewList[T any](data *T, len uint) List[T] {
+func NewList[T any, Len AnyInteger](data *T, len Len) List[T] {
 	return List[T]{
-		list[T]{
+		list: list[T]{
 			data: data,
-			len:  len,
+			len:  uintptr(len),
 		},
 	}
 }
@@ -20,15 +31,16 @@ func NewList[T any](data *T, len uint) List[T] {
 // The underlying slice data is not copied, and the resulting List points at the
 // same array storage as the slice.
 func ToList[S ~[]T, T any](s S) List[T] {
-	return NewList[T](unsafe.SliceData([]T(s)), uint(len(s)))
+	return NewList[T](unsafe.SliceData([]T(s)), uintptr(len(s)))
 }
 
 // list represents the internal representation of a Component Model list.
 // It is intended to be embedded in a [List], so embedding types maintain
 // the methods defined on this type.
 type list[T any] struct {
+	_    HostLayout
 	data *T
-	len  uint
+	len  uintptr
 }
 
 // Slice returns a Go slice representing the List.
@@ -42,7 +54,7 @@ func (l list[T]) Data() *T {
 }
 
 // Len returns the length of the list.
-// TODO: should this return an int instead of a uint?
-func (l list[T]) Len() uint {
+// TODO: should this return an int instead of a uintptr?
+func (l list[T]) Len() uintptr {
 	return l.len
 }

src/internal/cm/option.go

@@ -3,7 +3,10 @@ package cm
 // Option represents a Component Model [option<T>] type.
 //
 // [option<T>]: https://component-model.bytecodealliance.org/design/wit.html#options
-type Option[T any] struct{ option[T] }
+type Option[T any] struct {
+	_ HostLayout
+	option[T]
+}
 
 // None returns an [Option] representing the none case,
 // equivalent to the zero value.
@@ -14,7 +17,7 @@ func None[T any]() Option[T] {
 // Some returns an [Option] representing the some case.
 func Some[T any](v T) Option[T] {
 	return Option[T]{
-		option[T]{
+		option: option[T]{
 			isSome: true,
 			some:   v,
 		},
@@ -25,6 +28,7 @@ func Some[T any](v T) Option[T] {
 // The first byte is a bool representing none or some,
 // followed by storage for the associated type T.
 type option[T any] struct {
+	_      HostLayout
 	isSome bool
 	some   T
 }
@@ -42,3 +46,14 @@ func (o *option[T]) Some() *T {
 	}
 	return nil
 }
+
+// Value returns T if o represents the some case,
+// or the zero value of T if o represents the none case.
+// This does not have a pointer receiver, so it can be chained.
+func (o option[T]) Value() T {
+	if !o.isSome {
+		var zero T
+		return zero
+	}
+	return o.some
+}

src/internal/cm/result.go

@@ -17,10 +17,22 @@ type BoolResult bool
 // Result represents a result sized to hold the Shape type.
 // The size of the Shape type must be greater than or equal to the size of OK and Err types.
 // For results with two zero-length types, use [BoolResult].
-type Result[Shape, OK, Err any] struct{ result[Shape, OK, Err] }
+type Result[Shape, OK, Err any] struct {
+	_ HostLayout
+	result[Shape, OK, Err]
+}
+
+// AnyResult is a type constraint for generic functions that accept any [Result] type.
+type AnyResult[Shape, OK, Err any] interface {
+	~struct {
+		_ HostLayout
+		result[Shape, OK, Err]
+	}
+}
 
 // result represents the internal representation of a Component Model result type.
 type result[Shape, OK, Err any] struct {
+	_     HostLayout
 	isErr bool
 	_     [0]OK
 	_     [0]Err
@@ -88,8 +100,8 @@ func (r *result[Shape, OK, Err]) validate() {
 
 // OK returns an OK result with shape Shape and type OK and Err.
 // Pass Result[OK, OK, Err] or Result[Err, OK, Err] as the first type argument.
-func OK[R ~struct{ result[Shape, OK, Err] }, Shape, OK, Err any](ok OK) R {
-	var r struct{ result[Shape, OK, Err] }
+func OK[R AnyResult[Shape, OK, Err], Shape, OK, Err any](ok OK) R {
+	var r Result[Shape, OK, Err]
 	r.validate()
 	r.isErr = ResultOK
 	*((*OK)(unsafe.Pointer(&r.data))) = ok
@@ -98,8 +110,8 @@ func OK[R ~struct{ result[Shape, OK, Err] }, Shape, OK, Err any](ok OK) R {
 
 // Err returns an error result with shape Shape and type OK and Err.
 // Pass Result[OK, OK, Err] or Result[Err, OK, Err] as the first type argument.
-func Err[R ~struct{ result[Shape, OK, Err] }, Shape, OK, Err any](err Err) R {
-	var r struct{ result[Shape, OK, Err] }
+func Err[R AnyResult[Shape, OK, Err], Shape, OK, Err any](err Err) R {
+	var r Result[Shape, OK, Err]
 	r.validate()
 	r.isErr = ResultErr
 	*((*Err)(unsafe.Pointer(&r.data))) = err

src/internal/cm/tuple.go

@@ -4,6 +4,7 @@ package cm
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple[T0, T1 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 }
@@ -12,6 +13,7 @@ type Tuple[T0, T1 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple3[T0, T1, T2 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -21,6 +23,7 @@ type Tuple3[T0, T1, T2 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple4[T0, T1, T2, T3 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -31,6 +34,7 @@ type Tuple4[T0, T1, T2, T3 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple5[T0, T1, T2, T3, T4 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -42,6 +46,7 @@ type Tuple5[T0, T1, T2, T3, T4 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple6[T0, T1, T2, T3, T4, T5 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -54,6 +59,7 @@ type Tuple6[T0, T1, T2, T3, T4, T5 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple7[T0, T1, T2, T3, T4, T5, T6 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -67,6 +73,7 @@ type Tuple7[T0, T1, T2, T3, T4, T5, T6 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple8[T0, T1, T2, T3, T4, T5, T6, T7 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -81,6 +88,7 @@ type Tuple8[T0, T1, T2, T3, T4, T5, T6, T7 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple9[T0, T1, T2, T3, T4, T5, T6, T7, T8 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -96,6 +104,7 @@ type Tuple9[T0, T1, T2, T3, T4, T5, T6, T7, T8 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple10[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9 any] struct {
+	_  HostLayout
 	F0 T0
 	F1 T1
 	F2 T2
@@ -112,6 +121,7 @@ type Tuple10[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple11[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10 any] struct {
+	_   HostLayout
 	F0  T0
 	F1  T1
 	F2  T2
@@ -129,6 +139,7 @@ type Tuple11[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple12[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11 any] struct {
+	_   HostLayout
 	F0  T0
 	F1  T1
 	F2  T2
@@ -147,6 +158,7 @@ type Tuple12[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple13[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12 any] struct {
+	_   HostLayout
 	F0  T0
 	F1  T1
 	F2  T2
@@ -166,6 +178,7 @@ type Tuple13[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12 any] struct {
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple14[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13 any] struct {
+	_   HostLayout
 	F0  T0
 	F1  T1
 	F2  T2
@@ -186,6 +199,7 @@ type Tuple14[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13 any] str
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple15[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14 any] struct {
+	_   HostLayout
 	F0  T0
 	F1  T1
 	F2  T2
@@ -207,6 +221,7 @@ type Tuple15[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14 any
 //
 // [Component Model tuple]: https://component-model.bytecodealliance.org/design/wit.html#tuples
 type Tuple16[T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15 any] struct {
+	_   HostLayout
 	F0  T0
 	F1  T1
 	F2  T2

src/internal/cm/variant.go

@@ -12,7 +12,18 @@ type Discriminant interface {
 // Variant represents a loosely-typed Component Model variant.
 // Shape and Align must be non-zero sized types. To create a variant with no associated
 // types, use an enum.
-type Variant[Tag Discriminant, Shape, Align any] struct{ variant[Tag, Shape, Align] }
+type Variant[Tag Discriminant, Shape, Align any] struct {
+	_ HostLayout
+	variant[Tag, Shape, Align]
+}
+
+// AnyVariant is a type constraint for generic functions that accept any [Variant] type.
+type AnyVariant[Tag Discriminant, Shape, Align any] interface {
+	~struct {
+		_ HostLayout
+		variant[Tag, Shape, Align]
+	}
+}
 
 // NewVariant returns a [Variant] with tag of type Disc, storage and GC shape of type Shape,
 // aligned to type Align, with a value of type T.
@@ -26,7 +37,7 @@ func NewVariant[Tag Discriminant, Shape, Align any, T any](tag Tag, data T) Vari
 
 // New returns a [Variant] with tag of type Disc, storage and GC shape of type Shape,
 // aligned to type Align, with a value of type T.
-func New[V ~struct{ variant[Tag, Shape, Align] }, Tag Discriminant, Shape, Align any, T any](tag Tag, data T) V {
+func New[V AnyVariant[Tag, Shape, Align], Tag Discriminant, Shape, Align any, T any](tag Tag, data T) V {
 	validateVariant[Tag, Shape, Align, T]()
 	var v variant[Tag, Shape, Align]
 	v.tag = tag
@@ -35,7 +46,7 @@ func New[V ~struct{ variant[Tag, Shape, Align] }, Tag Discriminant, Shape, Align
 }
 
 // Case returns a non-nil *T if the [Variant] case is equal to tag, otherwise it returns nil.
-func Case[T any, V ~struct{ variant[Tag, Shape, Align] }, Tag Discriminant, Shape, Align any](v *V, tag Tag) *T {
+func Case[T any, V AnyVariant[Tag, Shape, Align], Tag Discriminant, Shape, Align any](v *V, tag Tag) *T {
 	validateVariant[Tag, Shape, Align, T]()
 	v2 := (*variant[Tag, Shape, Align])(unsafe.Pointer(v))
 	if v2.tag == tag {
@@ -47,6 +58,7 @@ func Case[T any, V ~struct{ variant[Tag, Shape, Align] }, Tag Discriminant, Shap
 // variant is the internal representation of a Component Model variant.
 // Shape and Align must be non-zero sized types.
 type variant[Tag Discriminant, Shape, Align any] struct {
+	_    HostLayout
 	tag  Tag
 	_    [0]Align
 	data Shape // [unsafe.Sizeof(*(*Shape)(unsafe.Pointer(nil)))]byte

src/internal/gclayout/gclayout.go

@@ -0,0 +1,33 @@
+package gclayout
+
+import "unsafe"
+
+// Internal constants for gc layout
+// See runtime/gc_precise.go
+
+var (
+	NoPtrs  unsafe.Pointer
+	Pointer unsafe.Pointer
+	String  unsafe.Pointer
+	Slice   unsafe.Pointer
+)
+
+func init() {
+	var sizeBits uintptr
+
+	switch unsafe.Sizeof(uintptr(0)) {
+	case 8:
+		sizeBits = 6
+	case 4:
+		sizeBits = 5
+	case 2:
+		sizeBits = 4
+	}
+
+	var sizeShift = sizeBits + 1
+
+	NoPtrs = unsafe.Pointer(uintptr(0b0<<sizeShift) | uintptr(0b1<<1) | uintptr(1))
+	Pointer = unsafe.Pointer(uintptr(0b1<<sizeShift) | uintptr(0b1<<1) | uintptr(1))
+	String = unsafe.Pointer(uintptr(0b01<<sizeShift) | uintptr(0b10<<1) | uintptr(1))
+	Slice = unsafe.Pointer(uintptr(0b001<<sizeShift) | uintptr(0b11<<1) | uintptr(1))
+}

src/internal/task/task.go

@@ -30,3 +30,6 @@ type Task struct {
 // the given function and falls back to the default stack size. It is replaced
 // with a load from a special section just before codegen.
 func getGoroutineStackSize(fn uintptr) uintptr
+
+//go:linkname runtime_alloc runtime.alloc
+func runtime_alloc(size uintptr, layout unsafe.Pointer) unsafe.Pointer

src/internal/task/task_asyncify.go

@@ -35,11 +35,16 @@ type state struct {
 type stackState struct {
 	// asyncify is the stack pointer of the asyncify stack.
 	// This starts from the bottom and grows upwards.
-	asyncifysp uintptr
+	asyncifysp unsafe.Pointer
 
 	// asyncify is stack pointer of the C stack.
 	// This starts from the top and grows downwards.
-	csp uintptr
+	csp unsafe.Pointer
+
+	// Pointer to the first (lowest address) of the stack. It must never be
+	// overwritten. It can be checked from time to time to see whether a stack
+	// overflow happened in the past.
+	canaryPtr *uintptr
 }
 
 // start creates and starts a new goroutine with the given function and arguments.
@@ -63,12 +68,18 @@ func (s *state) initialize(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	s.args = args
 
 	// Create a stack.
-	stack := make([]uintptr, stackSize/unsafe.Sizeof(uintptr(0)))
+	stack := runtime_alloc(stackSize, nil)
+
+	// Set up the stack canary, a random number that should be checked when
+	// switching from the task back to the scheduler. The stack canary pointer
+	// points to the first word of the stack. If it has changed between now and
+	// the next stack switch, there was a stack overflow.
+	s.canaryPtr = (*uintptr)(stack)
+	*s.canaryPtr = stackCanary
 
 	// Calculate stack base addresses.
-	s.asyncifysp = uintptr(unsafe.Pointer(&stack[0]))
-	s.csp = uintptr(unsafe.Pointer(&stack[0])) + uintptr(len(stack))*unsafe.Sizeof(uintptr(0))
-	stack[0] = stackCanary
+	s.asyncifysp = unsafe.Add(stack, unsafe.Sizeof(uintptr(0)))
+	s.csp = unsafe.Add(stack, stackSize)
 }
 
 //go:linkname runqueuePushBack runtime.runqueuePushBack
@@ -85,14 +96,11 @@ func Current() *Task {
 // Pause suspends the current task and returns to the scheduler.
 // This function may only be called when running on a goroutine stack, not when running on the system stack.
 func Pause() {
-	// This is mildly unsafe but this is also the only place we can do this.
-	if *(*uintptr)(unsafe.Pointer(currentTask.state.asyncifysp)) != stackCanary {
+	if *currentTask.state.canaryPtr != stackCanary {
 		runtimePanic("stack overflow")
 	}
 
 	currentTask.state.unwind()
-
-	*(*uintptr)(unsafe.Pointer(currentTask.state.asyncifysp)) = stackCanary
 }
 
 //export tinygo_unwind
@@ -113,7 +121,7 @@ func (t *Task) Resume() {
 	}
 	currentTask = prevTask
 	t.gcData.swap()
-	if t.state.asyncifysp > t.state.csp {
+	if uintptr(t.state.asyncifysp) > uintptr(t.state.csp) {
 		runtimePanic("stack overflow")
 	}
 }

src/internal/task/task_stack.go

@@ -104,9 +104,6 @@ var startTask [0]uint8
 //go:linkname runqueuePushBack runtime.runqueuePushBack
 func runqueuePushBack(*Task)
 
-//go:linkname runtime_alloc runtime.alloc
-func runtime_alloc(size uintptr, layout unsafe.Pointer) unsafe.Pointer
-
 // start creates and starts a new goroutine with the given function and arguments.
 // The new goroutine is scheduled to run later.
 func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {

src/internal/wasi/cli/v0.2.0/command/command.wit.go

@@ -1,6 +1,4 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package command represents the world "wasi:cli/command@0.2.0".
 package command

src/internal/wasi/cli/v0.2.0/environment/environment.wasm.go

@@ -0,0 +1,21 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package environment
+
+import (
+	"internal/cm"
+)
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/environment@0.2.0 get-environment
+//go:noescape
+func wasmimport_GetEnvironment(result *cm.List[[2]string])
+
+//go:wasmimport wasi:cli/environment@0.2.0 get-arguments
+//go:noescape
+func wasmimport_GetArguments(result *cm.List[string])
+
+//go:wasmimport wasi:cli/environment@0.2.0 initial-cwd
+//go:noescape
+func wasmimport_InitialCWD(result *cm.Option[string])

src/internal/wasi/cli/v0.2.0/environment/environment.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package environment represents the imported interface "wasi:cli/environment@0.2.0".
 package environment
 
@@ -28,10 +26,6 @@ func GetEnvironment() (result cm.List[[2]string]) {
 	return
 }
 
-//go:wasmimport wasi:cli/environment@0.2.0 get-environment
-//go:noescape
-func wasmimport_GetEnvironment(result *cm.List[[2]string])
-
 // GetArguments represents the imported function "get-arguments".
 //
 // Get the POSIX-style arguments to the program.
@@ -44,10 +38,6 @@ func GetArguments() (result cm.List[string]) {
 	return
 }
 
-//go:wasmimport wasi:cli/environment@0.2.0 get-arguments
-//go:noescape
-func wasmimport_GetArguments(result *cm.List[string])
-
 // InitialCWD represents the imported function "initial-cwd".
 //
 // Return a path that programs should use as their initial current working
@@ -60,7 +50,3 @@ func InitialCWD() (result cm.Option[string]) {
 	wasmimport_InitialCWD(&result)
 	return
 }
-
-//go:wasmimport wasi:cli/environment@0.2.0 initial-cwd
-//go:noescape
-func wasmimport_InitialCWD(result *cm.Option[string])

src/internal/wasi/cli/v0.2.0/exit/exit.wasm.go

@@ -0,0 +1,9 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package exit
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/exit@0.2.0 exit
+//go:noescape
+func wasmimport_Exit(status0 uint32)

src/internal/wasi/cli/v0.2.0/exit/exit.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package exit represents the imported interface "wasi:cli/exit@0.2.0".
 package exit
 
@@ -21,7 +19,3 @@ func Exit(status cm.BoolResult) {
 	wasmimport_Exit((uint32)(status0))
 	return
 }
-
-//go:wasmimport wasi:cli/exit@0.2.0 exit
-//go:noescape
-func wasmimport_Exit(status0 uint32)

src/internal/wasi/cli/v0.2.0/run/run.exports.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 package run
 
 import (

src/internal/wasi/cli/v0.2.0/run/run.wasm.go

@@ -0,0 +1,17 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package run
+
+import (
+	"internal/cm"
+)
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmexport wasi:cli/run@0.2.0#run
+//export wasi:cli/run@0.2.0#run
+func wasmexport_Run() (result0 uint32) {
+	result := Exports.Run()
+	result0 = cm.BoolToU32(result)
+	return
+}

src/internal/wasi/cli/v0.2.0/run/run.wit.go

@@ -1,18 +1,4 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package run represents the exported interface "wasi:cli/run@0.2.0".
 package run
-
-import (
-	"internal/cm"
-)
-
-//go:wasmexport wasi:cli/run@0.2.0#run
-//export wasi:cli/run@0.2.0#run
-func wasmexport_Run() (result0 uint32) {
-	result := Exports.Run()
-	result0 = cm.BoolToU32(result)
-	return
-}

src/internal/wasi/cli/v0.2.0/stderr/stderr.wasm.go

@@ -0,0 +1,9 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package stderr
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/stderr@0.2.0 get-stderr
+//go:noescape
+func wasmimport_GetStderr() (result0 uint32)

src/internal/wasi/cli/v0.2.0/stderr/stderr.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package stderr represents the imported interface "wasi:cli/stderr@0.2.0".
 package stderr
 
@@ -10,17 +8,18 @@ import (
 	"internal/wasi/io/v0.2.0/streams"
 )
 
+// OutputStream represents the imported type alias "wasi:cli/stderr@0.2.0#output-stream".
+//
+// See [streams.OutputStream] for more information.
+type OutputStream = streams.OutputStream
+
 // GetStderr represents the imported function "get-stderr".
 //
 //	get-stderr: func() -> output-stream
 //
 //go:nosplit
-func GetStderr() (result streams.OutputStream) {
+func GetStderr() (result OutputStream) {
 	result0 := wasmimport_GetStderr()
-	result = cm.Reinterpret[streams.OutputStream]((uint32)(result0))
+	result = cm.Reinterpret[OutputStream]((uint32)(result0))
 	return
 }
-
-//go:wasmimport wasi:cli/stderr@0.2.0 get-stderr
-//go:noescape
-func wasmimport_GetStderr() (result0 uint32)

src/internal/wasi/cli/v0.2.0/stdin/stdin.wasm.go

@@ -0,0 +1,9 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package stdin
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/stdin@0.2.0 get-stdin
+//go:noescape
+func wasmimport_GetStdin() (result0 uint32)

src/internal/wasi/cli/v0.2.0/stdin/stdin.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package stdin represents the imported interface "wasi:cli/stdin@0.2.0".
 package stdin
 
@@ -10,17 +8,18 @@ import (
 	"internal/wasi/io/v0.2.0/streams"
 )
 
+// InputStream represents the imported type alias "wasi:cli/stdin@0.2.0#input-stream".
+//
+// See [streams.InputStream] for more information.
+type InputStream = streams.InputStream
+
 // GetStdin represents the imported function "get-stdin".
 //
 //	get-stdin: func() -> input-stream
 //
 //go:nosplit
-func GetStdin() (result streams.InputStream) {
+func GetStdin() (result InputStream) {
 	result0 := wasmimport_GetStdin()
-	result = cm.Reinterpret[streams.InputStream]((uint32)(result0))
+	result = cm.Reinterpret[InputStream]((uint32)(result0))
 	return
 }
-
-//go:wasmimport wasi:cli/stdin@0.2.0 get-stdin
-//go:noescape
-func wasmimport_GetStdin() (result0 uint32)

src/internal/wasi/cli/v0.2.0/stdout/stdout.wasm.go

@@ -0,0 +1,9 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package stdout
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/stdout@0.2.0 get-stdout
+//go:noescape
+func wasmimport_GetStdout() (result0 uint32)

src/internal/wasi/cli/v0.2.0/stdout/stdout.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package stdout represents the imported interface "wasi:cli/stdout@0.2.0".
 package stdout
 
@@ -10,17 +8,18 @@ import (
 	"internal/wasi/io/v0.2.0/streams"
 )
 
+// OutputStream represents the imported type alias "wasi:cli/stdout@0.2.0#output-stream".
+//
+// See [streams.OutputStream] for more information.
+type OutputStream = streams.OutputStream
+
 // GetStdout represents the imported function "get-stdout".
 //
 //	get-stdout: func() -> output-stream
 //
 //go:nosplit
-func GetStdout() (result streams.OutputStream) {
+func GetStdout() (result OutputStream) {
 	result0 := wasmimport_GetStdout()
-	result = cm.Reinterpret[streams.OutputStream]((uint32)(result0))
+	result = cm.Reinterpret[OutputStream]((uint32)(result0))
 	return
 }
-
-//go:wasmimport wasi:cli/stdout@0.2.0 get-stdout
-//go:noescape
-func wasmimport_GetStdout() (result0 uint32)

src/internal/wasi/cli/v0.2.0/terminal-input/terminal-input.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package terminalinput represents the imported interface "wasi:cli/terminal-input@0.2.0".
 //
 // Terminal input.
@@ -32,7 +30,3 @@ func (self TerminalInput) ResourceDrop() {
 	wasmimport_TerminalInputResourceDrop((uint32)(self0))
 	return
 }
-
-//go:wasmimport wasi:cli/terminal-input@0.2.0 [resource-drop]terminal-input
-//go:noescape
-func wasmimport_TerminalInputResourceDrop(self0 uint32)

src/internal/wasi/cli/v0.2.0/terminal-input/terminalinput.wasm.go

@@ -0,0 +1,9 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package terminalinput
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/terminal-input@0.2.0 [resource-drop]terminal-input
+//go:noescape
+func wasmimport_TerminalInputResourceDrop(self0 uint32)

src/internal/wasi/cli/v0.2.0/terminal-output/terminal-output.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package terminaloutput represents the imported interface "wasi:cli/terminal-output@0.2.0".
 //
 // Terminal output.
@@ -32,7 +30,3 @@ func (self TerminalOutput) ResourceDrop() {
 	wasmimport_TerminalOutputResourceDrop((uint32)(self0))
 	return
 }
-
-//go:wasmimport wasi:cli/terminal-output@0.2.0 [resource-drop]terminal-output
-//go:noescape
-func wasmimport_TerminalOutputResourceDrop(self0 uint32)

src/internal/wasi/cli/v0.2.0/terminal-output/terminaloutput.wasm.go

@@ -0,0 +1,9 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package terminaloutput
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/terminal-output@0.2.0 [resource-drop]terminal-output
+//go:noescape
+func wasmimport_TerminalOutputResourceDrop(self0 uint32)

src/internal/wasi/cli/v0.2.0/terminal-stderr/terminal-stderr.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package terminalstderr represents the imported interface "wasi:cli/terminal-stderr@0.2.0".
 //
 // An interface providing an optional `terminal-output` for stderr as a
@@ -13,6 +11,11 @@ import (
 	terminaloutput "internal/wasi/cli/v0.2.0/terminal-output"
 )
 
+// TerminalOutput represents the imported type alias "wasi:cli/terminal-stderr@0.2.0#terminal-output".
+//
+// See [terminaloutput.TerminalOutput] for more information.
+type TerminalOutput = terminaloutput.TerminalOutput
+
 // GetTerminalStderr represents the imported function "get-terminal-stderr".
 //
 // If stderr is connected to a terminal, return a `terminal-output` handle
@@ -21,11 +24,7 @@ import (
 //	get-terminal-stderr: func() -> option<terminal-output>
 //
 //go:nosplit
-func GetTerminalStderr() (result cm.Option[terminaloutput.TerminalOutput]) {
+func GetTerminalStderr() (result cm.Option[TerminalOutput]) {
 	wasmimport_GetTerminalStderr(&result)
 	return
 }
-
-//go:wasmimport wasi:cli/terminal-stderr@0.2.0 get-terminal-stderr
-//go:noescape
-func wasmimport_GetTerminalStderr(result *cm.Option[terminaloutput.TerminalOutput])

src/internal/wasi/cli/v0.2.0/terminal-stderr/terminalstderr.wasm.go

@@ -0,0 +1,13 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package terminalstderr
+
+import (
+	"internal/cm"
+)
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/terminal-stderr@0.2.0 get-terminal-stderr
+//go:noescape
+func wasmimport_GetTerminalStderr(result *cm.Option[TerminalOutput])

src/internal/wasi/cli/v0.2.0/terminal-stdin/terminal-stdin.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package terminalstdin represents the imported interface "wasi:cli/terminal-stdin@0.2.0".
 //
 // An interface providing an optional `terminal-input` for stdin as a
@@ -13,6 +11,11 @@ import (
 	terminalinput "internal/wasi/cli/v0.2.0/terminal-input"
 )
 
+// TerminalInput represents the imported type alias "wasi:cli/terminal-stdin@0.2.0#terminal-input".
+//
+// See [terminalinput.TerminalInput] for more information.
+type TerminalInput = terminalinput.TerminalInput
+
 // GetTerminalStdin represents the imported function "get-terminal-stdin".
 //
 // If stdin is connected to a terminal, return a `terminal-input` handle
@@ -21,11 +24,7 @@ import (
 //	get-terminal-stdin: func() -> option<terminal-input>
 //
 //go:nosplit
-func GetTerminalStdin() (result cm.Option[terminalinput.TerminalInput]) {
+func GetTerminalStdin() (result cm.Option[TerminalInput]) {
 	wasmimport_GetTerminalStdin(&result)
 	return
 }
-
-//go:wasmimport wasi:cli/terminal-stdin@0.2.0 get-terminal-stdin
-//go:noescape
-func wasmimport_GetTerminalStdin(result *cm.Option[terminalinput.TerminalInput])

src/internal/wasi/cli/v0.2.0/terminal-stdin/terminalstdin.wasm.go

@@ -0,0 +1,13 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package terminalstdin
+
+import (
+	"internal/cm"
+)
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/terminal-stdin@0.2.0 get-terminal-stdin
+//go:noescape
+func wasmimport_GetTerminalStdin(result *cm.Option[TerminalInput])

src/internal/wasi/cli/v0.2.0/terminal-stdout/terminal-stdout.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package terminalstdout represents the imported interface "wasi:cli/terminal-stdout@0.2.0".
 //
 // An interface providing an optional `terminal-output` for stdout as a
@@ -13,6 +11,11 @@ import (
 	terminaloutput "internal/wasi/cli/v0.2.0/terminal-output"
 )
 
+// TerminalOutput represents the imported type alias "wasi:cli/terminal-stdout@0.2.0#terminal-output".
+//
+// See [terminaloutput.TerminalOutput] for more information.
+type TerminalOutput = terminaloutput.TerminalOutput
+
 // GetTerminalStdout represents the imported function "get-terminal-stdout".
 //
 // If stdout is connected to a terminal, return a `terminal-output` handle
@@ -21,11 +24,7 @@ import (
 //	get-terminal-stdout: func() -> option<terminal-output>
 //
 //go:nosplit
-func GetTerminalStdout() (result cm.Option[terminaloutput.TerminalOutput]) {
+func GetTerminalStdout() (result cm.Option[TerminalOutput]) {
 	wasmimport_GetTerminalStdout(&result)
 	return
 }
-
-//go:wasmimport wasi:cli/terminal-stdout@0.2.0 get-terminal-stdout
-//go:noescape
-func wasmimport_GetTerminalStdout(result *cm.Option[terminaloutput.TerminalOutput])

src/internal/wasi/cli/v0.2.0/terminal-stdout/terminalstdout.wasm.go

@@ -0,0 +1,13 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package terminalstdout
+
+import (
+	"internal/cm"
+)
+
+// This file contains wasmimport and wasmexport declarations for "wasi:cli@0.2.0".
+
+//go:wasmimport wasi:cli/terminal-stdout@0.2.0 get-terminal-stdout
+//go:noescape
+func wasmimport_GetTerminalStdout(result *cm.Option[TerminalOutput])

src/internal/wasi/clocks/v0.2.0/monotonic-clock/monotonic-clock.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package monotonicclock represents the imported interface "wasi:clocks/monotonic-clock@0.2.0".
 //
 // WASI Monotonic Clock is a clock API intended to let users measure elapsed
@@ -21,6 +19,11 @@ import (
 	"internal/wasi/io/v0.2.0/poll"
 )
 
+// Pollable represents the imported type alias "wasi:clocks/monotonic-clock@0.2.0#pollable".
+//
+// See [poll.Pollable] for more information.
+type Pollable = poll.Pollable
+
 // Instant represents the u64 "wasi:clocks/monotonic-clock@0.2.0#instant".
 //
 // An instant in time, in nanoseconds. An instant is relative to an
@@ -53,10 +56,6 @@ func Now() (result Instant) {
 	return
 }
 
-//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 now
-//go:noescape
-func wasmimport_Now() (result0 uint64)
-
 // Resolution represents the imported function "resolution".
 //
 // Query the resolution of the clock. Returns the duration of time
@@ -71,10 +70,6 @@ func Resolution() (result Duration) {
 	return
 }
 
-//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 resolution
-//go:noescape
-func wasmimport_Resolution() (result0 uint64)
-
 // SubscribeInstant represents the imported function "subscribe-instant".
 //
 // Create a `pollable` which will resolve once the specified instant
@@ -83,17 +78,13 @@ func wasmimport_Resolution() (result0 uint64)
 //	subscribe-instant: func(when: instant) -> pollable
 //
 //go:nosplit
-func SubscribeInstant(when Instant) (result poll.Pollable) {
+func SubscribeInstant(when Instant) (result Pollable) {
 	when0 := (uint64)(when)
 	result0 := wasmimport_SubscribeInstant((uint64)(when0))
-	result = cm.Reinterpret[poll.Pollable]((uint32)(result0))
+	result = cm.Reinterpret[Pollable]((uint32)(result0))
 	return
 }
 
-//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 subscribe-instant
-//go:noescape
-func wasmimport_SubscribeInstant(when0 uint64) (result0 uint32)
-
 // SubscribeDuration represents the imported function "subscribe-duration".
 //
 // Create a `pollable` which will resolve once the given duration has
@@ -103,13 +94,9 @@ func wasmimport_SubscribeInstant(when0 uint64) (result0 uint32)
 //	subscribe-duration: func(when: duration) -> pollable
 //
 //go:nosplit
-func SubscribeDuration(when Duration) (result poll.Pollable) {
+func SubscribeDuration(when Duration) (result Pollable) {
 	when0 := (uint64)(when)
 	result0 := wasmimport_SubscribeDuration((uint64)(when0))
-	result = cm.Reinterpret[poll.Pollable]((uint32)(result0))
+	result = cm.Reinterpret[Pollable]((uint32)(result0))
 	return
 }
-
-//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 subscribe-duration
-//go:noescape
-func wasmimport_SubscribeDuration(when0 uint64) (result0 uint32)

src/internal/wasi/clocks/v0.2.0/monotonic-clock/monotonicclock.wasm.go

@@ -0,0 +1,21 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package monotonicclock
+
+// This file contains wasmimport and wasmexport declarations for "wasi:clocks@0.2.0".
+
+//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 now
+//go:noescape
+func wasmimport_Now() (result0 uint64)
+
+//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 resolution
+//go:noescape
+func wasmimport_Resolution() (result0 uint64)
+
+//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 subscribe-instant
+//go:noescape
+func wasmimport_SubscribeInstant(when0 uint64) (result0 uint32)
+
+//go:wasmimport wasi:clocks/monotonic-clock@0.2.0 subscribe-duration
+//go:noescape
+func wasmimport_SubscribeDuration(when0 uint64) (result0 uint32)

src/internal/wasi/clocks/v0.2.0/wall-clock/wall-clock.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package wallclock represents the imported interface "wasi:clocks/wall-clock@0.2.0".
 //
 // WASI Wall Clock is a clock API intended to let users query the current
@@ -20,6 +18,10 @@
 // It is intended for reporting the current date and time for humans.
 package wallclock
 
+import (
+	"internal/cm"
+)
+
 // DateTime represents the record "wasi:clocks/wall-clock@0.2.0#datetime".
 //
 // A time and date in seconds plus nanoseconds.
@@ -29,6 +31,7 @@ package wallclock
 //		nanoseconds: u32,
 //	}
 type DateTime struct {
+	_           cm.HostLayout
 	Seconds     uint64
 	Nanoseconds uint32
 }
@@ -57,10 +60,6 @@ func Now() (result DateTime) {
 	return
 }
 
-//go:wasmimport wasi:clocks/wall-clock@0.2.0 now
-//go:noescape
-func wasmimport_Now(result *DateTime)
-
 // Resolution represents the imported function "resolution".
 //
 // Query the resolution of the clock.
@@ -74,7 +73,3 @@ func Resolution() (result DateTime) {
 	wasmimport_Resolution(&result)
 	return
 }
-
-//go:wasmimport wasi:clocks/wall-clock@0.2.0 resolution
-//go:noescape
-func wasmimport_Resolution(result *DateTime)

src/internal/wasi/clocks/v0.2.0/wall-clock/wallclock.wasm.go

@@ -0,0 +1,13 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package wallclock
+
+// This file contains wasmimport and wasmexport declarations for "wasi:clocks@0.2.0".
+
+//go:wasmimport wasi:clocks/wall-clock@0.2.0 now
+//go:noescape
+func wasmimport_Now(result *DateTime)
+
+//go:wasmimport wasi:clocks/wall-clock@0.2.0 resolution
+//go:noescape
+func wasmimport_Resolution(result *DateTime)

src/internal/wasi/filesystem/v0.2.0/preopens/preopens.wasm.go

@@ -0,0 +1,13 @@
+// Code generated by wit-bindgen-go. DO NOT EDIT.
+
+package preopens
+
+import (
+	"internal/cm"
+)
+
+// This file contains wasmimport and wasmexport declarations for "wasi:filesystem@0.2.0".
+
+//go:wasmimport wasi:filesystem/preopens@0.2.0 get-directories
+//go:noescape
+func wasmimport_GetDirectories(result *cm.List[cm.Tuple[Descriptor, string]])

src/internal/wasi/filesystem/v0.2.0/preopens/preopens.wit.go

@@ -1,7 +1,5 @@
 // Code generated by wit-bindgen-go. DO NOT EDIT.
 
-//go:build !wasip1
-
 // Package preopens represents the imported interface "wasi:filesystem/preopens@0.2.0".
 package preopens
 
@@ -10,6 +8,11 @@ import (
 	"internal/wasi/filesystem/v0.2.0/types"
 )
 
+// Descriptor represents the imported type alias "wasi:filesystem/preopens@0.2.0#descriptor".
+//
+// See [types.Descriptor] for more information.
+type Descriptor = types.Descriptor
+
 // GetDirectories represents the imported function "get-directories".
 //
 // Return the set of preopened directories, and their path.
@@ -17,11 +20,7 @@ import (
 //	get-directories: func() -> list<tuple<descriptor, string>>
 //
 //go:nosplit
-func GetDirectories() (result cm.List[cm.Tuple[types.Descriptor, string]]) {
+func GetDirectories() (result cm.List[cm.Tuple[Descriptor, string]]) {
 	wasmimport_GetDirectories(&result)
 	return
 }
-
-//go:wasmimport wasi:filesystem/preopens@0.2.0 get-directories
-//go:noescape
-func wasmimport_GetDirectories(result *cm.List[cm.Tuple[types.Descriptor, string]])