syscall.Getpagesize(): add test, implement for Linux and Windows

src/syscall/syscall_libc.go

@@ -251,10 +251,6 @@ func Mprotect(b []byte, prot int) (err error) {
 	return
 }
 
-func Getpagesize() int {
-	return int(libc_getpagesize())
-}
-
 func Environ() []string {
 
 	// This function combines all the environment into a single allocation.
@@ -372,10 +368,6 @@ func libc_munmap(addr unsafe.Pointer, length uintptr) int32
 //export mprotect
 func libc_mprotect(addr unsafe.Pointer, len uintptr, prot int32) int32
 
-// int getpagesize();
-//export getpagesize
-func libc_getpagesize() int32
-
 // int chdir(const char *pathname, mode_t mode);
 //export chdir
 func libc_chdir(pathname *byte) int32

src/syscall/syscall_libc_darwin.go

@@ -267,6 +267,14 @@ func readdir_r(dir uintptr, entry *Dirent, result **Dirent) (err error) {
 	return
 }
 
+func Getpagesize() int {
+	return int(libc_getpagesize())
+}
+
 // int pipe(int32 *fds);
 //export pipe
 func libc_pipe(fds *int32) int32
+
+// int getpagesize();
+//export getpagesize
+func libc_getpagesize() int32

src/syscall/syscall_libc_nintendoswitch.go

@@ -67,3 +67,7 @@ func getErrno() error {
 func Pipe2(p []int, flags int) (err error) {
 	return ENOSYS // TODO
 }
+
+func Getpagesize() int {
+	return 4096 // TODO
+}

src/syscall/syscall_libc_wasi.go

@@ -296,6 +296,11 @@ func Pipe2(p []int, flags int) (err error) {
 	return ENOSYS // TODO
 }
 
+func Getpagesize() int {
+	// per upstream
+	return 65536
+}
+
 // int stat(const char *path, struct stat * buf);
 //export stat
 func libc_stat(pathname *byte, ptr unsafe.Pointer) int32

src/syscall/syscall_nonhosted.go

@@ -205,3 +205,9 @@ type Timeval struct {
 	Sec  int64
 	Usec int64
 }
+
+func Getpagesize() int {
+	// There is no right value to return here, but 4096 is a
+	// common assumption when pagesize is unknown
+	return 4096
+}