cmd/internal/sys: migrate support.go functions to new internal pkg

Separate out the functions from cmd/internal/sys/support.go and
migrate them to a new package internal/platform, so that functions such as
"RaceDetectorSupported" can be called from tests in std as well as in
cmd. This isn't a complete move of everything in cmd/internal/sys;
there are still many functions left.

The original version of this CL (patch set 1) called the new package
"internal/sys", but for packages that needed both "internal/sys" and
"cmd/internal/sys" the import of the former had to be done with a
different name, which was confusing and also required a hack in
cmd/dist.

Updates #56006.

Change-Id: I866d62e75adbf3a640a06e2c7386a6e9e2a18d91
Reviewed-on: https://go-review.googlesource.com/c/go/+/438475
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>

2 files changed, 0 insertions, 185 deletions

diff --git a/src/cmd/internal/sys/supported.go b/src/cmd/internal/sys/supported.go
deleted file mode 100644
index ee98d0548e..0000000000
--- a/src/cmd/internal/sys/supported.go
+++ /dev/null
@@ -1,167 +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.
-
-package sys
-
-// RaceDetectorSupported reports whether goos/goarch supports the race
-// detector. There is a copy of this function in cmd/dist/test.go.
-// Race detector only supports 48-bit VMA on arm64. But it will always
-// return true for arm64, because we don't have VMA size information during
-// the compile time.
-func RaceDetectorSupported(goos, goarch string) bool {
-	switch goos {
-	case "linux":
-		return goarch == "amd64" || goarch == "ppc64le" || goarch == "arm64" || goarch == "s390x"
-	case "darwin":
-		return goarch == "amd64" || goarch == "arm64"
-	case "freebsd", "netbsd", "openbsd", "windows":
-		return goarch == "amd64"
-	default:
-		return false
-	}
-}
-
-// MSanSupported reports whether goos/goarch supports the memory
-// sanitizer option.
-// There is a copy of this function in misc/cgo/testsanitizers/cc_test.go.
-func MSanSupported(goos, goarch string) bool {
-	switch goos {
-	case "linux":
-		return goarch == "amd64" || goarch == "arm64"
-	default:
-		return false
-	}
-}
-
-// ASanSupported reports whether goos/goarch supports the address
-// sanitizer option.
-// There is a copy of this function in misc/cgo/testsanitizers/cc_test.go.
-func ASanSupported(goos, goarch string) bool {
-	switch goos {
-	case "linux":
-		return goarch == "arm64" || goarch == "amd64" || goarch == "riscv64" || goarch == "ppc64le"
-	default:
-		return false
-	}
-}
-
-// FuzzSupported reports whether goos/goarch supports fuzzing
-// ('go test -fuzz=.').
-func FuzzSupported(goos, goarch string) bool {
-	switch goos {
-	case "darwin", "freebsd", "linux", "windows":
-		return true
-	default:
-		return false
-	}
-}
-
-// FuzzInstrumented reports whether fuzzing on goos/goarch uses coverage
-// instrumentation. (FuzzInstrumented implies FuzzSupported.)
-func FuzzInstrumented(goos, goarch string) bool {
-	switch goarch {
-	case "amd64", "arm64":
-		// TODO(#14565): support more architectures.
-		return FuzzSupported(goos, goarch)
-	default:
-		return false
-	}
-}
-
-// MustLinkExternal reports whether goos/goarch requires external linking.
-// (This is the opposite of internal/testenv.CanInternalLink. Keep them in sync.)
-func MustLinkExternal(goos, goarch string) bool {
-	switch goos {
-	case "android":
-		if goarch != "arm64" {
-			return true
-		}
-	case "ios":
-		if goarch == "arm64" {
-			return true
-		}
-	}
-	return false
-}
-
-// BuildModeSupported reports whether goos/goarch supports the given build mode
-// using the given compiler.
-func BuildModeSupported(compiler, buildmode, goos, goarch string) bool {
-	if compiler == "gccgo" {
-		return true
-	}
-
-	platform := goos + "/" + goarch
-
-	switch buildmode {
-	case "archive":
-		return true
-
-	case "c-archive":
-		// TODO(bcmills): This seems dubious.
-		// Do we really support c-archive mode on js/wasm‽
-		return platform != "linux/ppc64"
-
-	case "c-shared":
-		switch platform {
-		case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/ppc64le", "linux/riscv64", "linux/s390x",
-			"android/amd64", "android/arm", "android/arm64", "android/386",
-			"freebsd/amd64",
-			"darwin/amd64", "darwin/arm64",
-			"windows/amd64", "windows/386", "windows/arm64":
-			return true
-		}
-		return false
-
-	case "default":
-		return true
-
-	case "exe":
-		return true
-
-	case "pie":
-		switch platform {
-		case "linux/386", "linux/amd64", "linux/arm", "linux/arm64", "linux/ppc64le", "linux/riscv64", "linux/s390x",
-			"android/amd64", "android/arm", "android/arm64", "android/386",
-			"freebsd/amd64",
-			"darwin/amd64", "darwin/arm64",
-			"ios/amd64", "ios/arm64",
-			"aix/ppc64",
-			"windows/386", "windows/amd64", "windows/arm":
-			return true
-		}
-		return false
-
-	case "shared":
-		switch platform {
-		case "linux/386", "linux/amd64", "linux/arm", "linux/arm64", "linux/ppc64le", "linux/s390x":
-			return true
-		}
-		return false
-
-	case "plugin":
-		switch platform {
-		case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/s390x", "linux/ppc64le",
-			"android/amd64", "android/arm", "android/arm64", "android/386",
-			"darwin/amd64", "darwin/arm64",
-			"freebsd/amd64":
-			return true
-		}
-		return false
-
-	default:
-		return false
-	}
-}
-
-func InternalLinkPIESupported(goos, goarch string) bool {
-	switch goos + "/" + goarch {
-	case "darwin/amd64", "darwin/arm64",
-		"linux/amd64", "linux/arm64", "linux/ppc64le",
-		"android/arm64",
-		"windows-amd64", "windows-386", "windows-arm":
-		return true
-	}
-	return false
-}
diff --git a/src/cmd/internal/sys/supported_test.go b/src/cmd/internal/sys/supported_test.go
deleted file mode 100644
index 1217814af5..0000000000
--- a/src/cmd/internal/sys/supported_test.go
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2020 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.
-
-package sys
-
-import (
-	"internal/testenv"
-	"runtime"
-	"testing"
-)
-
-func TestMustLinkExternalMatchesTestenv(t *testing.T) {
-	// MustLinkExternal and testenv.CanInternalLink are the exact opposite.
-	if b := MustLinkExternal(runtime.GOOS, runtime.GOARCH); b != !testenv.CanInternalLink() {
-		t.Fatalf("MustLinkExternal() == %v, testenv.CanInternalLink() == %v, don't match", b, testenv.CanInternalLink())
-	}
-}