1 files changed, 151 insertions, 0 deletions
diff --git a/src/runtime/os_wasm.go b/src/runtime/os_wasm.go
new file mode 100644
index 0000000..ce260de
--- /dev/null
+++ b/src/runtime/os_wasm.go
@@ -0,0 +1,151 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime
+
+import (
+	"runtime/internal/atomic"
+	"unsafe"
+)
+
+func osinit() {
+	// https://webassembly.github.io/spec/core/exec/runtime.html#memory-instances
+	physPageSize = 64 * 1024
+	initBloc()
+	ncpu = 1
+	getg().m.procid = 2
+}
+
+const _SIGSEGV = 0xb
+
+func sigpanic() {
+	gp := getg()
+	if !canpanic() {
+		throw("unexpected signal during runtime execution")
+	}
+
+	// js only invokes the exception handler for memory faults.
+	gp.sig = _SIGSEGV
+	panicmem()
+}
+
+// func exitThread(wait *uint32)
+// FIXME: wasm doesn't have atomic yet
+func exitThread(wait *atomic.Uint32)
+
+type mOS struct{}
+
+func osyield()
+
+//go:nosplit
+func osyield_no_g() {
+	osyield()
+}
+
+type sigset struct{}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the parent thread (main thread in case of bootstrap), can allocate memory.
+func mpreinit(mp *m) {
+	mp.gsignal = malg(32 * 1024)
+	mp.gsignal.m = mp
+}
+
+//go:nosplit
+func usleep_no_g(usec uint32) {
+	usleep(usec)
+}
+
+//go:nosplit
+func sigsave(p *sigset) {
+}
+
+//go:nosplit
+func msigrestore(sigmask sigset) {
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func clearSignalHandlers() {
+}
+
+//go:nosplit
+func sigblock(exiting bool) {
+}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the new thread, cannot allocate memory.
+func minit() {
+}
+
+// Called from dropm to undo the effect of an minit.
+func unminit() {
+}
+
+// Called from exitm, but not from drop, to undo the effect of thread-owned
+// resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
+func mdestroy(mp *m) {
+}
+
+// wasm has no signals
+const _NSIG = 0
+
+func signame(sig uint32) string {
+	return ""
+}
+
+func crash() {
+	*(*int32)(nil) = 0
+}
+
+func initsig(preinit bool) {
+}
+
+// May run with m.p==nil, so write barriers are not allowed.
+//
+//go:nowritebarrier
+func newosproc(mp *m) {
+	throw("newosproc: not implemented")
+}
+
+//go:linkname os_sigpipe os.sigpipe
+func os_sigpipe() {
+	throw("too many writes on closed pipe")
+}
+
+//go:linkname syscall_now syscall.now
+func syscall_now() (sec int64, nsec int32) {
+	sec, nsec, _ = time_now()
+	return
+}
+
+//go:nosplit
+func cputicks() int64 {
+	// runtime·nanotime() is a poor approximation of CPU ticks that is enough for the profiler.
+	return nanotime()
+}
+
+// gsignalStack is unused on js.
+type gsignalStack struct{}
+
+const preemptMSupported = false
+
+func preemptM(mp *m) {
+	// No threads, so nothing to do.
+}
+
+// getfp returns the frame pointer register of its caller or 0 if not implemented.
+// TODO: Make this a compiler intrinsic
+func getfp() uintptr { return 0 }
+
+func setProcessCPUProfiler(hz int32) {}
+func setThreadCPUProfiler(hz int32)  {}
+func sigdisable(uint32)              {}
+func sigenable(uint32)               {}
+func sigignore(uint32)               {}
+
+// Stubs so tests can link correctly. These should never be called.
+func open(name *byte, mode, perm int32) int32        { panic("not implemented") }
+func closefd(fd int32) int32                         { panic("not implemented") }
+func read(fd int32, p unsafe.Pointer, n int32) int32 { panic("not implemented") }