all: add GOOS=ios

Introduce GOOS=ios for iOS systems. GOOS=ios matches "darwin"
build tag, like GOOS=android matches "linux" and GOOS=illumos
matches "solaris". Only ios/arm64 is supported (ios/amd64 is
not).

GOOS=ios and GOOS=darwin remain essentially the same at this
point. They will diverge at later time, to differentiate macOS
and iOS.

Uses of GOOS=="darwin" are changed to (GOOS=="darwin" || GOOS=="ios"),
except if it clearly means macOS (e.g. GOOS=="darwin" && GOARCH=="amd64"),
it remains GOOS=="darwin".

Updates #38485.

Change-Id: I4faacdc1008f42434599efb3c3ad90763a83b67c
Reviewed-on: https://go-review.googlesource.com/c/go/+/254740
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

5 files changed, 7 insertions, 7 deletions

diff --git a/src/syscall/exec_unix.go b/src/syscall/exec_unix.go
index cb08b7084c..725c2bc1f9 100644
--- a/src/syscall/exec_unix.go
+++ b/src/syscall/exec_unix.go
@@ -296,7 +296,7 @@ func Exec(argv0 string, argv []string, envv []string) (err error) {
 			uintptr(unsafe.Pointer(argv0p)),
 			uintptr(unsafe.Pointer(&argvp[0])),
 			uintptr(unsafe.Pointer(&envvp[0])))
-	} else if runtime.GOOS == "darwin" {
+	} else if runtime.GOOS == "darwin" || runtime.GOOS == "ios" {
 		// Similarly on Darwin.
 		err1 = execveDarwin(argv0p, &argvp[0], &envvp[0])
 	} else {
diff --git a/src/syscall/sockcmsg_unix_other.go b/src/syscall/sockcmsg_unix_other.go
index fbafbf8341..3aaf7c3616 100644
--- a/src/syscall/sockcmsg_unix_other.go
+++ b/src/syscall/sockcmsg_unix_other.go
@@ -20,7 +20,7 @@ func cmsgAlignOf(salen int) int {
 	case "aix":
 		// There is no alignment on AIX.
 		salign = 1
-	case "darwin", "illumos", "solaris":
+	case "darwin", "ios", "illumos", "solaris":
 		// NOTE: It seems like 64-bit Darwin, Illumos and Solaris
 		// kernels still require 32-bit aligned access to network
 		// subsystem.
diff --git a/src/syscall/syscall_bsd.go b/src/syscall/syscall_bsd.go
index fda9d613d3..b52de7450f 100644
--- a/src/syscall/syscall_bsd.go
+++ b/src/syscall/syscall_bsd.go
@@ -277,7 +277,7 @@ func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 	if err != nil {
 		return
 	}
-	if runtime.GOOS == "darwin" && len == 0 {
+	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && len == 0 {
 		// Accepted socket has no address.
 		// This is likely due to a bug in xnu kernels,
 		// where instead of ECONNABORTED error socket
diff --git a/src/syscall/syscall_unix.go b/src/syscall/syscall_unix.go
index 56abce19cd..91c939e0ea 100644
--- a/src/syscall/syscall_unix.go
+++ b/src/syscall/syscall_unix.go
@@ -22,7 +22,7 @@ var (
 )
 
 const (
-	darwin64Bit = runtime.GOOS == "darwin" && sizeofPtr == 8
+	darwin64Bit = (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && sizeofPtr == 8
 	netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4
 )
 
diff --git a/src/syscall/syscall_unix_test.go b/src/syscall/syscall_unix_test.go
index 3c7982eefe..7e9bb0c3ac 100644
--- a/src/syscall/syscall_unix_test.go
+++ b/src/syscall/syscall_unix_test.go
@@ -70,7 +70,7 @@ func _() {
 // Thus this test also verifies that the Flock_t structure can be
 // roundtripped with F_SETLK and F_GETLK.
 func TestFcntlFlock(t *testing.T) {
-	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
+	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && runtime.GOARCH == "arm64" {
 		t.Skip("skipping; no child processes allowed on iOS")
 	}
 	flock := syscall.Flock_t{
@@ -336,7 +336,7 @@ func TestRlimit(t *testing.T) {
 	}
 	set := rlimit
 	set.Cur = set.Max - 1
-	if runtime.GOOS == "darwin" && set.Cur > 4096 {
+	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && set.Cur > 4096 {
 		// rlim_min for RLIMIT_NOFILE should be equal to
 		// or lower than kern.maxfilesperproc, which on
 		// some machines are 4096. See #40564.
@@ -353,7 +353,7 @@ func TestRlimit(t *testing.T) {
 	}
 	set = rlimit
 	set.Cur = set.Max - 1
-	if runtime.GOOS == "darwin" && set.Cur > 4096 {
+	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && set.Cur > 4096 {
 		set.Cur = 4096
 	}
 	if set != get {