all: remove scattered remnants of darwin/386

This removes all conditions and conditional code (that I could find)
that depended on darwin/386.

Fixes #37610.

Change-Id: I630d9ea13613fb7c0bcdb981e8367facff250ba0
Reviewed-on: https://go-review.googlesource.com/c/go/+/227582
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

18 files changed, 25 insertions, 83 deletions

diff --git a/api/except.txt b/api/except.txt
index 6316401897..ccfdf06c55 100644
--- a/api/except.txt
+++ b/api/except.txt
@@ -8,10 +8,6 @@ pkg os (linux-arm), const O_SYNC = 4096
 pkg os (linux-arm-cgo), const O_SYNC = 4096
 pkg os (linux-arm), const O_SYNC = 1052672
 pkg os (linux-arm-cgo), const O_SYNC = 1052672
-pkg syscall (darwin-386), const ImplementsGetwd = false
-pkg syscall (darwin-386), func Fchflags(string, int) error
-pkg syscall (darwin-386-cgo), const ImplementsGetwd = false
-pkg syscall (darwin-386-cgo), func Fchflags(string, int) error
 pkg syscall (darwin-amd64), const ImplementsGetwd = false
 pkg syscall (darwin-amd64), func Fchflags(string, int) error
 pkg syscall (darwin-amd64-cgo), const ImplementsGetwd = false
diff --git a/misc/cgo/test/sigaltstack.go b/misc/cgo/test/sigaltstack.go
index f501f9ba3a..8dfa1cb5ad 100644
--- a/misc/cgo/test/sigaltstack.go
+++ b/misc/cgo/test/sigaltstack.go
@@ -64,8 +64,6 @@ func testSigaltstack(t *testing.T) {
 	switch {
 	case runtime.GOOS == "solaris", runtime.GOOS == "illumos", runtime.GOOS == "darwin" && runtime.GOARCH == "arm64":
 		t.Skipf("switching signal stack not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
-	case runtime.GOOS == "darwin" && runtime.GOARCH == "386":
-		t.Skipf("sigaltstack fails on darwin/386")
 	}
 
 	C.changeSignalStack()
diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index a7ef8f27d5..b9b78bf57d 100644
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -902,7 +902,7 @@ func (t *tester) extLink() bool {
 	switch pair {
 	case "aix-ppc64",
 		"android-arm", "android-arm64",
-		"darwin-386", "darwin-amd64", "darwin-arm64",
+		"darwin-amd64", "darwin-arm64",
 		"dragonfly-amd64",
 		"freebsd-386", "freebsd-amd64", "freebsd-arm",
 		"linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le", "linux-mips64", "linux-mips64le", "linux-mips", "linux-mipsle", "linux-s390x",
@@ -963,7 +963,7 @@ func (t *tester) supportedBuildmode(mode string) bool {
 		}
 		switch pair {
 		case "aix-ppc64",
-			"darwin-386", "darwin-amd64", "darwin-arm64",
+			"darwin-amd64", "darwin-arm64",
 			"linux-amd64", "linux-386", "linux-ppc64le", "linux-s390x",
 			"freebsd-amd64",
 			"windows-amd64", "windows-386":
@@ -973,7 +973,7 @@ func (t *tester) supportedBuildmode(mode string) bool {
 	case "c-shared":
 		switch pair {
 		case "linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le", "linux-s390x",
-			"darwin-amd64", "darwin-386",
+			"darwin-amd64",
 			"freebsd-amd64",
 			"android-arm", "android-arm64", "android-386",
 			"windows-amd64", "windows-386":
@@ -1069,7 +1069,7 @@ func (t *tester) cgoTest(dt *distTest) error {
 
 	pair := gohostos + "-" + goarch
 	switch pair {
-	case "darwin-386", "darwin-amd64",
+	case "darwin-amd64",
 		"openbsd-386", "openbsd-amd64",
 		"windows-386", "windows-amd64":
 		// test linkmode=external, but __thread not supported, so skip testtls.
diff --git a/src/cmd/go/testdata/script/link_syso_issue33139.txt b/src/cmd/go/testdata/script/link_syso_issue33139.txt
index 03169bf5e9..46b0ef4200 100644
--- a/src/cmd/go/testdata/script/link_syso_issue33139.txt
+++ b/src/cmd/go/testdata/script/link_syso_issue33139.txt
@@ -12,10 +12,6 @@
 # See: https://github.com/golang/go/issues/36739
 [linux] [riscv64] skip
 
-# External linking is not supported on darwin/386 (10.14+).
-# See: https://github.com/golang/go/issues/31751
-[darwin] [386] skip
-
 cc -c -o syso/objTestImpl.syso syso/src/objTestImpl.c
 go build -ldflags='-linkmode=external' ./cmd/main.go
 
diff --git a/src/cmd/internal/sys/supported.go b/src/cmd/internal/sys/supported.go
index efc07af56b..c27b3b986d 100644
--- a/src/cmd/internal/sys/supported.go
+++ b/src/cmd/internal/sys/supported.go
@@ -69,7 +69,7 @@ func BuildModeSupported(compiler, buildmode, goos, goarch string) bool {
 		case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/ppc64le", "linux/s390x",
 			"android/amd64", "android/arm", "android/arm64", "android/386",
 			"freebsd/amd64",
-			"darwin/amd64", "darwin/386",
+			"darwin/amd64",
 			"windows/amd64", "windows/386":
 			return true
 		}
diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index f7b8e04ddf..62cf2262bd 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -540,7 +540,7 @@ func (ctxt *Link) loadlib() {
 	// We now have enough information to determine the link mode.
 	determineLinkMode(ctxt)
 
-	if ctxt.LinkMode == LinkExternal && !iscgo && !(objabi.GOOS == "darwin" && ctxt.BuildMode != BuildModePlugin && (ctxt.Arch.Family == sys.AMD64 || ctxt.Arch.Family == sys.I386)) {
+	if ctxt.LinkMode == LinkExternal && !iscgo && !(objabi.GOOS == "darwin" && ctxt.BuildMode != BuildModePlugin && ctxt.Arch.Family == sys.AMD64) {
 		// This indicates a user requested -linkmode=external.
 		// The startup code uses an import of runtime/cgo to decide
 		// whether to initialize the TLS.  So give it one. This could
diff --git a/src/cmd/link/internal/ld/sym.go b/src/cmd/link/internal/ld/sym.go
index 2284963f59..ff47c688b6 100644
--- a/src/cmd/link/internal/ld/sym.go
+++ b/src/cmd/link/internal/ld/sym.go
@@ -95,14 +95,11 @@ func (ctxt *Link) computeTLSOffset() {
 
 			/*
 			 * For x86, Apple has reserved a slot in the TLS for Go. See issue 23617.
-			 * That slot is at offset 0x30 on amd64, and 0x18 on 386.
+			 * That slot is at offset 0x30 on amd64.
 			 * The slot will hold the G pointer.
-			 * These constants should match those in runtime/sys_darwin_{386,amd64}.s
-			 * and runtime/cgo/gcc_darwin_{386,amd64}.c.
+			 * These constants should match those in runtime/sys_darwin_amd64.s
+			 * and runtime/cgo/gcc_darwin_amd64.c.
 			 */
-		case sys.I386:
-			ctxt.Tlsoffset = 0x18
-
 		case sys.AMD64:
 			ctxt.Tlsoffset = 0x30
 
diff --git a/src/cmd/oldlink/internal/ld/lib.go b/src/cmd/oldlink/internal/ld/lib.go
index a6c86af6cf..0fc786f1bf 100644
--- a/src/cmd/oldlink/internal/ld/lib.go
+++ b/src/cmd/oldlink/internal/ld/lib.go
@@ -435,7 +435,7 @@ func (ctxt *Link) loadlib() {
 	// We now have enough information to determine the link mode.
 	determineLinkMode(ctxt)
 
-	if ctxt.LinkMode == LinkExternal && !iscgo && ctxt.LibraryByPkg["runtime/cgo"] == nil && !(objabi.GOOS == "darwin" && ctxt.BuildMode != BuildModePlugin && (ctxt.Arch.Family == sys.AMD64 || ctxt.Arch.Family == sys.I386)) {
+	if ctxt.LinkMode == LinkExternal && !iscgo && ctxt.LibraryByPkg["runtime/cgo"] == nil && !(objabi.GOOS == "darwin" && ctxt.BuildMode != BuildModePlugin && ctxt.Arch.Family == sys.AMD64) {
 		// This indicates a user requested -linkmode=external.
 		// The startup code uses an import of runtime/cgo to decide
 		// whether to initialize the TLS.  So give it one. This could
diff --git a/src/cmd/oldlink/internal/ld/sym.go b/src/cmd/oldlink/internal/ld/sym.go
index a470ddbca8..4f697d0627 100644
--- a/src/cmd/oldlink/internal/ld/sym.go
+++ b/src/cmd/oldlink/internal/ld/sym.go
@@ -93,14 +93,11 @@ func (ctxt *Link) computeTLSOffset() {
 
 			/*
 			 * For x86, Apple has reserved a slot in the TLS for Go. See issue 23617.
-			 * That slot is at offset 0x30 on amd64, and 0x18 on 386.
+			 * That slot is at offset 0x30 on amd64.
 			 * The slot will hold the G pointer.
 			 * These constants should match those in runtime/sys_darwin_{386,amd64}.s
 			 * and runtime/cgo/gcc_darwin_{386,amd64}.c.
 			 */
-		case sys.I386:
-			ctxt.Tlsoffset = 0x18
-
 		case sys.AMD64:
 			ctxt.Tlsoffset = 0x30
 
diff --git a/src/go/build/doc.go b/src/go/build/doc.go
index 47dec5a05d..bf60ff7fc2 100644
--- a/src/go/build/doc.go
+++ b/src/go/build/doc.go
@@ -86,11 +86,11 @@
 // of the individual constraints. That is, the build constraints:
 //
 //	// +build linux darwin
-//	// +build 386
+//	// +build amd64
 //
 // corresponds to the boolean formula:
 //
-//	(linux OR darwin) AND 386
+//	(linux OR darwin) AND amd64
 //
 // During a particular build, the following words are satisfied:
 //
diff --git a/src/os/wait_waitid.go b/src/os/wait_waitid.go
index c57bace90f..6c904e54db 100644
--- a/src/os/wait_waitid.go
+++ b/src/os/wait_waitid.go
@@ -23,8 +23,7 @@ const _P_PID = 1
 func (p *Process) blockUntilWaitable() (bool, error) {
 	// The waitid system call expects a pointer to a siginfo_t,
 	// which is 128 bytes on all GNU/Linux systems.
-	// On Darwin, it requires greater than or equal to 64 bytes
-	// for darwin/386 and 104 bytes for darwin/amd64.
+	// On darwin/amd64, it requires 104 bytes.
 	// We don't care about the values it returns.
 	var siginfo [16]uint64
 	psig := &siginfo[0]
diff --git a/src/runtime/asm_386.s b/src/runtime/asm_386.s
index 8f0ec08f80..11863fba39 100644
--- a/src/runtime/asm_386.s
+++ b/src/runtime/asm_386.s
@@ -199,10 +199,6 @@ needtls:
 	// skip runtime·ldt0setup(SB) and tls test on Plan 9 in all cases
 	JMP	ok
 #endif
-#ifdef GOOS_darwin
-	// skip runtime·ldt0setup(SB) on Darwin
-	JMP	ok
-#endif
 
 	// set up %gs
 	CALL	ldt0setup<>(SB)
diff --git a/src/runtime/defs_darwin.go b/src/runtime/defs_darwin.go
index de1489f032..cc8c475387 100644
--- a/src/runtime/defs_darwin.go
+++ b/src/runtime/defs_darwin.go
@@ -8,7 +8,6 @@
 Input to cgo.
 
 GOARCH=amd64 go tool cgo -cdefs defs_darwin.go >defs_darwin_amd64.h
-GOARCH=386 go tool cgo -cdefs defs_darwin.go >defs_darwin_386.h
 */
 
 package runtime
diff --git a/src/runtime/signal_386.go b/src/runtime/signal_386.go
index bceffa6f4e..2f390f12f7 100644
--- a/src/runtime/signal_386.go
+++ b/src/runtime/signal_386.go
@@ -37,22 +37,6 @@ func (c *sigctxt) fault() uintptr { return uintptr(c.sigaddr()) }
 
 // preparePanic sets up the stack to look like a call to sigpanic.
 func (c *sigctxt) preparePanic(sig uint32, gp *g) {
-	if GOOS == "darwin" {
-		// Work around Leopard bug that doesn't set FPE_INTDIV.
-		// Look at instruction to see if it is a divide.
-		// Not necessary in Snow Leopard (si_code will be != 0).
-		if sig == _SIGFPE && gp.sigcode0 == 0 {
-			pc := (*[4]byte)(unsafe.Pointer(gp.sigpc))
-			i := 0
-			if pc[i] == 0x66 { // 16-bit instruction prefix
-				i++
-			}
-			if pc[i] == 0xF6 || pc[i] == 0xF7 {
-				gp.sigcode0 = _FPE_INTDIV
-			}
-		}
-	}
-
 	pc := uintptr(c.eip())
 	sp := uintptr(c.esp())
 
diff --git a/src/runtime/sys_darwin.go b/src/runtime/sys_darwin.go
index d2d1822aab..1b136f88a8 100644
--- a/src/runtime/sys_darwin.go
+++ b/src/runtime/sys_darwin.go
@@ -67,6 +67,17 @@ func syscall_syscall(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
 }
 func syscall()
 
+//go:linkname syscall_syscallX syscall.syscallX
+//go:nosplit
+//go:cgo_unsafe_args
+func syscall_syscallX(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
+	entersyscallblock()
+	libcCall(unsafe.Pointer(funcPC(syscallX)), unsafe.Pointer(&fn))
+	exitsyscall()
+	return
+}
+func syscallX()
+
 //go:linkname syscall_syscall6 syscall.syscall6
 //go:nosplit
 //go:cgo_unsafe_args
diff --git a/src/runtime/sys_darwin_64.go b/src/runtime/sys_darwin_64.go
deleted file mode 100644
index 07b0bb54af..0000000000
--- a/src/runtime/sys_darwin_64.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build darwin
-// +build amd64 arm64
-
-package runtime
-
-import "unsafe"
-
-//go:linkname syscall_syscallX syscall.syscallX
-//go:nosplit
-//go:cgo_unsafe_args
-func syscall_syscallX(fn, a1, a2, a3 uintptr) (r1, r2, err uintptr) {
-	entersyscallblock()
-	libcCall(unsafe.Pointer(funcPC(syscallX)), unsafe.Pointer(&fn))
-	exitsyscall()
-	return
-}
-func syscallX()
diff --git a/src/runtime/vlrt.go b/src/runtime/vlrt.go
index e4d1be5d8a..87370f870d 100644
--- a/src/runtime/vlrt.go
+++ b/src/runtime/vlrt.go
@@ -130,9 +130,6 @@ func uint64mod(n, d uint64) uint64 {
 	return r
 }
 
-//go:nosplit
-// nosplit because division is used in syscall context in nanotime on darwin/386
-// where stack splits are not allowed.
 func int64div(n, d int64) int64 {
 	// Check for 32 bit operands
 	if int64(int32(n)) == n && int64(int32(d)) == d {
diff --git a/src/syscall/mkall.sh b/src/syscall/mkall.sh
index 7e624c5a21..826512a177 100755
--- a/src/syscall/mkall.sh
+++ b/src/syscall/mkall.sh
@@ -121,13 +121,6 @@ aix_ppc64)
 	mksyscall="./mksyscall_libc.pl -aix"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	;;
-darwin_386)
-	mkerrors="$mkerrors -m32"
-	mksyscall="./mksyscall.pl -l32 -darwin"
-	mksysnum="./mksysnum_darwin.pl /usr/include/sys/syscall.h"
-	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
-	mkasm="go run mkasm_darwin.go"
-	;;
 darwin_amd64)
 	mkerrors="$mkerrors -m64"
 	mksyscall="./mksyscall.pl -darwin"