support WASI target (#1373)

* initial commit for WASI support * merge "time" package with wasi build tag * override syscall package with wasi build tag * create runtime_wasm_{js,wasi}.go files * create syscall_wasi.go file * create time/zoneinfo_wasi.go file as the replacement of zoneinfo_js.go * add targets/wasi.json target * set visbility hidden for runtime extern variables Accodring to the WASI docs (https://github.com/WebAssembly/WASI/blob/master/design/application-abi.md#current-unstable-abi), none of exports of WASI executable(Command) should no be accessed. v0.19.0 of bytecodealliance/wasmetime, which is often refered to as the reference implementation of WASI, does not accept any exports except functions and the only limited variables like "table", "memory". * merge syscall_{baremetal,wasi}.go * fix js target build * mv wasi functions to syscall/wasi && implement sleepTicks * WASI: set visibility hidden for globals variables * mv back syscall/wasi/* to runtime package * WASI: add test * unexport wasi types * WASI test: fix wasmtime path * stop changing visibility of runtime.alloc * use GOOS=linux, GOARCH=arm for wasi target Signed-off-by: mathetake <takeshi@tetrate.io> * WASI: fix build tags for os/runtime packages Signed-off-by: mathetake <takeshi@tetrate.io> * run WASI test only on Linux Signed-off-by: mathetake <takeshi@tetrate.io> * set InternalLinkage instead of changing visibility Signed-off-by: mathetake <takeshi@tetrate.io>
2026-08-13 07:23:39 +00:00 · 2020-09-30 04:58:03 +09:00
parent d39c7abb4d
commit f50ad3585d
17 changed files with 241 additions and 72 deletions
@@ -0,0 +1,117 @@
+// +build wasm,wasi
+
+package runtime
+
+import (
+	"unsafe"
+)
+
+type timeUnit int64
+
+//export _start
+func _start() {
+	// These need to be initialized early so that the heap can be initialized.
+	heapStart = uintptr(unsafe.Pointer(&heapStartSymbol))
+	heapEnd = uintptr(wasm_memory_size(0) * wasmPageSize)
+	run()
+}
+
+func ticksToNanoseconds(ticks timeUnit) int64 {
+	return int64(ticks)
+}
+
+func nanosecondsToTicks(ns int64) timeUnit {
+	return timeUnit(ns)
+}
+
+const (
+	asyncScheduler           = false
+	timePrecisionNanoseconds = 1000 // TODO: how can we determine the appropriate `precision`?
+)
+
+var (
+	sleepTicksSubscription = __wasi_subscription_t{
+		userData: 0,
+		u: __wasi_subscription_u_t{
+			tag: __wasi_eventtype_t_clock,
+			u: __wasi_subscription_clock_t{
+				userData:  0,
+				id:        0,
+				timeout:   0,
+				precision: timePrecisionNanoseconds,
+				flags:     0,
+			},
+		},
+	}
+	sleepTicksResult  = __wasi_event_t{}
+	sleepTicksNEvents uint32
+)
+
+func sleepTicks(d timeUnit) {
+	sleepTicksSubscription.u.u.timeout = int64(d)
+	poll_oneoff(&sleepTicksSubscription, &sleepTicksResult, 1, &sleepTicksNEvents)
+}
+
+func ticks() timeUnit {
+	var nano int64
+	clock_time_get(0, timePrecisionNanoseconds, &nano)
+	return timeUnit(nano)
+}
+
+// Implementations of wasi_unstable APIs
+
+//go:wasm-module wasi_unstable
+//export clock_time_get
+func clock_time_get(clockid uint32, precision uint64, time *int64) (errno uint16)
+
+//go:wasm-module wasi_unstable
+//export poll_oneoff
+func poll_oneoff(in *__wasi_subscription_t, out *__wasi_event_t, nsubscriptions uint32, nevents *uint32) (errno uint16)
+
+type __wasi_eventtype_t = uint8
+
+const (
+	__wasi_eventtype_t_clock __wasi_eventtype_t = 0
+	// TODO: __wasi_eventtype_t_fd_read  __wasi_eventtype_t = 1
+	// TODO: __wasi_eventtype_t_fd_write __wasi_eventtype_t = 2
+)
+
+type (
+	// https://github.com/wasmerio/wasmer/blob/1.0.0-alpha3/lib/wasi/src/syscalls/types.rs#L584-L588
+	__wasi_subscription_t struct {
+		userData uint64
+		u        __wasi_subscription_u_t
+	}
+
+	__wasi_subscription_u_t struct {
+		tag __wasi_eventtype_t
+
+		// TODO: support fd_read/fd_write event
+		u __wasi_subscription_clock_t
+	}
+
+	// https://github.com/wasmerio/wasmer/blob/1.0.0-alpha3/lib/wasi/src/syscalls/types.rs#L711-L718
+	__wasi_subscription_clock_t struct {
+		userData  uint64
+		id        uint32
+		timeout   int64
+		precision int64
+		flags     uint16
+	}
+)
+
+type (
+	// https://github.com/wasmerio/wasmer/blob/1.0.0-alpha3/lib/wasi/src/syscalls/types.rs#L191-L198
+	__wasi_event_t struct {
+		userData  uint64
+		errno     uint16
+		eventType __wasi_eventtype_t
+
+		// only used for fd_read or fd_write events
+		// TODO: support fd_read/fd_write event
+		_ struct {
+			nBytes uint64
+			flags  uint16
+		}
+	}
+)