adjust build tags, un-export fork and execve, add signals for windows and macos

Author: leongross

src/os/exec_linux.go

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build posix || aix || linux || dragonfly || freebsd || (js && wasm) || netbsd || openbsd || solaris || wasip1
-// +build posix aix linux dragonfly freebsd js,wasm netbsd openbsd solaris wasip1
+//go:build linux
 
 package os
 
@@ -54,12 +53,12 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 		attr = new(ProcAttr)
 	}
 
-	pid, err = Fork()
+	pid, err = fork()
 	if err != nil {
 		return 0, err
 	} else {
 		// else code runs in child, which then should exec the new process
-		err = Execve(argv0, argv, attr.Env)
+		err = execve(argv0, argv, attr.Env)
 		if err != nil {
 			// exec failed
 			return 0, err

src/os/exec_other.go

@@ -3,6 +3,13 @@
 
 package os
 
+import "syscall"
+
+var (
+	Interrupt Signal = syscall.SIGINT
+	Kill      Signal = syscall.SIGKILL
+)
+
 func findProcess(pid int) (*Process, error) {
 	return &Process{Pid: pid}, nil
 }

src/os/osexec.go

@@ -1,5 +1,4 @@
 //go:build linux
-// +build linux
 
 package os
 
@@ -9,7 +8,7 @@ import (
 	"unsafe"
 )
 
-func Fork() (pid int, err error) {
+func fork() (pid int, err error) {
 	// ret := libc_fork()
 	// ret, _, _ := syscall.Syscall(syscall.SYS_FORK, 0, 0, 0)
 	ret, _, _ := syscall.Syscall(57, 0, 0, 0)
@@ -21,7 +20,7 @@ func Fork() (pid int, err error) {
 }
 
 // the golang standard library does not expose interfaces for execve and fork, so we define them here the same way via the libc wrapper
-func Execve(pathname string, argv []string, envv []string) (err error) {
+func execve(pathname string, argv []string, envv []string) (err error) {
 	argv0 := cstring(pathname)
 
 	// transform argv and envv into the format expected by execve

src/syscall/syscall_libc.go

@@ -224,6 +224,11 @@ func (w WaitStatus) Continued() bool    { return false }
 func (w WaitStatus) StopSignal() Signal { return 0 }
 func (w WaitStatus) TrapCause() int     { return 0 }
 
+// since rusage is quite a big struct and we stub it out anyway no need to define it here
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage uintptr) (wpid int, err error) {
+	return 0, ENOSYS // TODO
+}
+
 func Getenv(key string) (value string, found bool) {
 	data := cstring(key)
 	raw := libc_getenv(&data[0])
@@ -451,3 +456,8 @@ func libc_fork() int32
 //
 //export execve
 func libc_execve(filename *byte, argv **byte, envp **byte) int
+
+// pid_t wait4(pid_t pid, int *wstatus, int options, struct rusage *rusage);
+//
+//export wait4
+func libc_wait4(pid int32, wstatus *int, options int, rusage uintptr) int32