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go/src/runtime/env_posix.go
Richard Musiol 35ea62468b runtime: add js/wasm architecture
This commit adds the js/wasm architecture to the runtime package.
Currently WebAssembly has no support for threads yet, see
https://github.com/WebAssembly/design/issues/1073. Because of that,
there is no preemption of goroutines and no sysmon goroutine.

Design doc: https://docs.google.com/document/d/131vjr4DH6JFnb-blm_uRdaC0_Nv3OUwjEY5qVCxCup4
About WebAssembly assembly files: https://docs.google.com/document/d/1GRmy3rA4DiYtBlX-I1Jr_iHykbX8EixC3Mq0TCYqbKc

Updates #18892

Change-Id: I7f12d21b5180500d55ae9fd2f7e926a1731db391
Reviewed-on: https://go-review.googlesource.com/103877
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-05-08 00:17:34 +00:00

54 lines
1.3 KiB
Go

// Copyright 2012 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.
// +build darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris windows
package runtime
import "unsafe"
func gogetenv(key string) string {
env := environ()
if env == nil {
throw("getenv before env init")
}
for _, s := range env {
if len(s) > len(key) && s[len(key)] == '=' && s[:len(key)] == key {
return s[len(key)+1:]
}
}
return ""
}
var _cgo_setenv unsafe.Pointer // pointer to C function
var _cgo_unsetenv unsafe.Pointer // pointer to C function
// Update the C environment if cgo is loaded.
// Called from syscall.Setenv.
//go:linkname syscall_setenv_c syscall.setenv_c
func syscall_setenv_c(k string, v string) {
if _cgo_setenv == nil {
return
}
arg := [2]unsafe.Pointer{cstring(k), cstring(v)}
asmcgocall(_cgo_setenv, unsafe.Pointer(&arg))
}
// Update the C environment if cgo is loaded.
// Called from syscall.unsetenv.
//go:linkname syscall_unsetenv_c syscall.unsetenv_c
func syscall_unsetenv_c(k string) {
if _cgo_unsetenv == nil {
return
}
arg := [1]unsafe.Pointer{cstring(k)}
asmcgocall(_cgo_unsetenv, unsafe.Pointer(&arg))
}
func cstring(s string) unsafe.Pointer {
p := make([]byte, len(s)+1)
copy(p, s)
return unsafe.Pointer(&p[0])
}