From b0aef96340bed9dcaefcb2cf8ae2d2ce5718bd72 Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Fri, 21 Feb 2025 10:33:54 +0100
Subject: [PATCH] fix: only infer target for wasm when GOOS and GOARCH are set
 correctly, not just based on file extension

Signed-off-by: deadprogram <ron@hybridgroup.com>
---
 builder/builder_test.go |  1 -
 compileopts/target.go   | 31 +++----------------------------
 main.go                 | 20 ++++++++++++++++++--
 3 files changed, 21 insertions(+), 31 deletions(-)

diff --git a/builder/builder_test.go b/builder/builder_test.go
index 1d4584c34..ccccef30b 100644
--- a/builder/builder_test.go
+++ b/builder/builder_test.go
@@ -69,7 +69,6 @@ func TestClangAttributes(t *testing.T) {
 		{GOOS: "darwin", GOARCH: "arm64"},
 		{GOOS: "windows", GOARCH: "amd64"},
 		{GOOS: "windows", GOARCH: "arm64"},
-		{GOOS: "wasip1", GOARCH: "wasm"},
 	} {
 		name := "GOOS=" + options.GOOS + ",GOARCH=" + options.GOARCH
 		if options.GOARCH == "arm" {
diff --git a/compileopts/target.go b/compileopts/target.go
index 7893e5829..64cbc2daa 100644
--- a/compileopts/target.go
+++ b/compileopts/target.go
@@ -356,17 +356,7 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 			return nil, fmt.Errorf("invalid GOMIPS=%s: must be hardfloat or softfloat", options.GOMIPS)
 		}
 	case "wasm":
-		llvmarch = "wasm32"
-		spec.CPU = "generic"
-		spec.Features = "+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types"
-		spec.BuildTags = append(spec.BuildTags, "tinygo.wasm")
-		spec.CFlags = append(spec.CFlags,
-			"-mbulk-memory",
-			"-mnontrapping-fptoint",
-			"-mno-multivalue",
-			"-mno-reference-types",
-			"-msign-ext",
-		)
+		return nil, fmt.Errorf("GOARCH=wasm but GOOS is unset. Please set GOOS to wasm, wasip1, or wasip2.")
 	default:
 		return nil, fmt.Errorf("unknown GOARCH=%s", options.GOARCH)
 	}
@@ -446,23 +436,8 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 			"--no-insert-timestamp",
 			"--no-dynamicbase",
 		)
-	case "wasip1":
-		spec.GC = "" // use default GC
-		spec.Scheduler = "asyncify"
-		spec.Linker = "wasm-ld"
-		spec.RTLib = "compiler-rt"
-		spec.Libc = "wasi-libc"
-		spec.DefaultStackSize = 1024 * 64 // 64kB
-		spec.LDFlags = append(spec.LDFlags,
-			"--stack-first",
-			"--no-demangle",
-		)
-		spec.Emulator = "wasmtime run --dir={tmpDir}::/tmp {}"
-		spec.ExtraFiles = append(spec.ExtraFiles,
-			"src/runtime/asm_tinygowasm.S",
-			"src/internal/task/task_asyncify_wasm.S",
-		)
-		llvmos = "wasi"
+	case "wasm", "wasip1", "wasip2":
+		return nil, fmt.Errorf("GOOS=%s but GOARCH is unset. Please set GOARCH to wasm", options.GOOS)
 	default:
 		return nil, fmt.Errorf("unknown GOOS=%s", options.GOOS)
 	}
diff --git a/main.go b/main.go
index 1f2fc95b1..d4562fc4f 100644
--- a/main.go
+++ b/main.go
@@ -1684,8 +1684,24 @@ func main() {
 			usage(command)
 			os.Exit(1)
 		}
-		if options.Target == "" && filepath.Ext(outpath) == ".wasm" {
-			options.Target = "wasm"
+		if options.Target == "" {
+			switch {
+			case options.GOARCH == "wasm":
+				switch options.GOOS {
+				case "js":
+					options.Target = "wasm"
+				case "wasip1":
+					options.Target = "wasip1"
+				case "wasip2":
+					options.Target = "wasip2"
+				default:
+					fmt.Fprintln(os.Stderr, "GOARCH=wasm but GOOS is not set correctly. Please set GOOS to wasm, wasip1, or wasip2.")
+					os.Exit(1)
+				}
+			case filepath.Ext(outpath) == ".wasm":
+				fmt.Fprintln(os.Stderr, "you appear to want to build a wasm file, but have not specified either a target flag, or the GOARCH/GOOS to use.")
+				os.Exit(1)
+			}
 		}
 
 		err := Build(pkgName, outpath, options)