}

// Implemented in runtime package.
func runtime_BeforeFork()
func runtime_AfterFork()
func runtime_AfterForkInChild()

// Fork, dup fd onto 0..len(fd), and exec(argv0, argvv, envv) in child.
// If a dup or exec fails, write the errno error to pipe.
// (Pipe is close-on-exec so if exec succeeds, it will be closed.)
// In the child, this function must not acquire any locks, because

//
//go:norace
func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr *ProcAttr, sys *SysProcAttr, pipe int) (pid int, err Errno) {
	// Set up and fork. This returns immediately in the parent or
	// if there's an error.
	upid, pidfd, err, mapPipe, locked := forkAndExecInChild1(argv0, argv, envv, chroot, dir, attr, sys, pipe)
	if locked {
		runtime_AfterFork()
	}
	if err != 0 {

	val, err = syscall2(&libc_dup2, old, new)
	return
}

//go:linkname syscall_execve syscall.execve
//go:nosplit
func syscall_execve(path, argv, envp uintptr) (err uintptr) {
	_, err = syscall3(&libc_execve, path, argv, envp)
	return
}

// like exit, but must not split stack, for fork.
//
//go:linkname syscall_exit syscall.exit
//go:nosplit
func syscall_exit(code uintptr) {

    def "can relocate Windows specific _wmain symbol"() {
        makeSingleProject()
        file("src/main/cpp/main.cpp") << """
            #include <iostream>

            int wmain(int argc, wchar_t *argv[], wchar_t *envp[] ) {
                std::cout << "hello world!" << std::endl;
                return 0;
            }
        """

        when:
        succeeds("unexport")
        then:

#include "textflag.h"
#include "cgo/abi_loong64.h"

TEXT _rt0_loong64_linux(SB),NOSPLIT|NOFRAME,$0
	// In a statically linked binary, the stack contains argc,
	// argv as argc string pointers followed by a NULL, envv as a
	// sequence of string pointers followed by a NULL, and auxv.
	// There is no TLS base pointer.
	MOVW	0(R3), R4	// argc
	ADDV	$8, R3, R5	// argv
	JMP	main(SB)

//sys	getcwd(buf []byte) (n int, err error)
//sys	sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error)
//sysnb fork() (pid int, err error)
//sysnb execve(path *byte, argv **byte, envp **byte) (err error)
//sysnb exit(res int) (err error)
//sys   ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
//sysnb getentropy(p []byte) (err error)

	SYS_READLINK             = 58  // { ssize_t|sys||readlink(const char *path, char *buf, size_t count); }
	SYS_EXECVE               = 59  // { int|sys||execve(const char *path, char * const *argp, char * const *envp); }
	SYS_UMASK                = 60  // { mode_t|sys||umask(mode_t newmask); }
	SYS_CHROOT               = 61  // { int|sys||chroot(const char *path); }
	SYS_VFORK                = 66  // { int|sys||vfork(void); }

	SYS_READLINK             = 58  // { ssize_t|sys||readlink(const char *path, char *buf, size_t count); }
	SYS_EXECVE               = 59  // { int|sys||execve(const char *path, char * const *argp, char * const *envp); }
	SYS_UMASK                = 60  // { mode_t|sys||umask(mode_t newmask); }
	SYS_CHROOT               = 61  // { int|sys||chroot(const char *path); }
	SYS_VFORK                = 66  // { int|sys||vfork(void); }

	SYS_READLINK             = 58  // { ssize_t|sys||readlink(const char *path, char *buf, size_t count); }
	SYS_EXECVE               = 59  // { int|sys||execve(const char *path, char * const *argp, char * const *envp); }
	SYS_UMASK                = 60  // { mode_t|sys||umask(mode_t newmask); }
	SYS_CHROOT               = 61  // { int|sys||chroot(const char *path); }
	SYS_VFORK                = 66  // { int|sys||vfork(void); }

	SYS_READLINK             = 58  // { ssize_t|sys||readlink(const char *path, char *buf, size_t count); }
	SYS_EXECVE               = 59  // { int|sys||execve(const char *path, char * const *argp, char * const *envp); }
	SYS_UMASK                = 60  // { mode_t|sys||umask(mode_t newmask); }
	SYS_CHROOT               = 61  // { int|sys||chroot(const char *path); }
	SYS_VFORK                = 66  // { int|sys||vfork(void); }