os/StartProcess: cleanup

remove old comments, replace explicit syscall numbers with named
variants, undo tempfile seed generation, remove old // +build tags,
improve StartProcess documentation.

Signed-off-by: leongross <[email protected]>

src/os/exec.go

@@ -61,7 +61,8 @@ type Process struct {
 	Pid int
 }
 
-// Wrapper for the forkExec function, which is a wrapper around the fork and execve system calls.
+// StartProcess starts a new process with the program, arguments and attributes specified by name, argv and attr.
+// Arguments to the process (os.Args) are passed via argv.
 func StartProcess(name string, argv []string, attr *ProcAttr) (*Process, error) {
 	return startProcess(name, argv, attr)
 }

src/os/exec_other.go

@@ -1,5 +1,4 @@
 //go:build (!aix && !android && !freebsd && !linux && !netbsd && !openbsd && !plan9 && !solaris) || baremetal || tinygo.wasm
-// +build !aix,!android,!freebsd,!linux,!netbsd,!openbsd,!plan9,!solaris baremetal tinygo.wasm
 
 package os
 

src/os/osexec.go

@@ -9,8 +9,7 @@ import (
 )
 
 func fork() (pid int, err error) {
-	// ret, _, _ := syscall.Syscall(syscall.SYS_FORK, 0, 0, 0)
-	ret, _, _ := syscall.Syscall(57, 0, 0, 0)
+	ret, _, _ := syscall.Syscall(syscall.SYS_FORK, 0, 0, 0)
 	if ret < 0 {
 		// TODO: parse the syscall return codes
 		return 0, errors.New("fork failed")
@@ -35,8 +34,7 @@ func execve(pathname string, argv []string, envv []string) (err error) {
 	}
 	env1[len(envv)] = nil
 
-	// fail, _, _ := syscall.Syscall(syscall.SYS_EXECVE, uintptr(unsafe.Pointer(&argv0[0])), uintptr(unsafe.Pointer(&argv1[0])), uintptr(unsafe.Pointer(&env1[0])))
-	fail, _, _ := syscall.Syscall(59, uintptr(unsafe.Pointer(&argv0[0])), uintptr(unsafe.Pointer(&argv1[0])), uintptr(unsafe.Pointer(&env1[0])))
+	fail, _, _ := syscall.Syscall(syscall.SYS_EXECVE, uintptr(unsafe.Pointer(&argv0[0])), uintptr(unsafe.Pointer(&argv1[0])), uintptr(unsafe.Pointer(&env1[0])))
 	if fail < 0 {
 		// TODO: parse the syscall return codes
 		return errors.New("execve failed")

src/os/tempfile.go

@@ -17,8 +17,7 @@ var minrandMutex sync.Mutex
 func init() {
 	// Avoid getting same results on every run
 	now := time.Now()
-	// seed := uint32(Getpid()) ^ uint32(now.Nanosecond()) ^ uint32(now.Unix())
-	seed := uint32(now.Nanosecond()) ^ uint32(now.Unix())
+	seed := uint32(Getpid()) ^ uint32(now.Nanosecond()) ^ uint32(now.Unix())
 	// initial state must be odd
 	minrandPreviousValue = seed | 1
 }

src/syscall/syscall_unix.go

@@ -1,5 +1,4 @@
 //go:build linux || unix
-// +build linux unix
 
 package syscall