feat: update gofmt code from go1.23.8

Author: ldez

gofmt/gofmt.go

@@ -555,7 +555,7 @@ func backupFile(filename string, data []byte, perm fs.FileMode) (string, error)
 		if err == nil {
 			break
 		}
-		if err != nil && !os.IsExist(err) {
+		if !os.IsExist(err) {
 			return "", err
 		}
 	}

gofmt/internal/cfg/cfg.go

@@ -36,6 +36,7 @@ const KnownEnv = `
 	GOAMD64
 	GOARCH
 	GOARM
+	GOARM64
 	GOBIN
 	GOCACHE
 	GOCACHEPROG
@@ -57,6 +58,7 @@ const KnownEnv = `
 	GOPPC64
 	GOPRIVATE
 	GOPROXY
+	GORISCV64
 	GOROOT
 	GOSUMDB
 	GOTMPDIR

gofmt/internal/platform/supported.go

@@ -26,7 +26,7 @@ func RaceDetectorSupported(goos, goarch string) bool {
 		return goarch == "amd64" || goarch == "ppc64le" || goarch == "arm64" || goarch == "s390x"
 	case "darwin":
 		return goarch == "amd64" || goarch == "arm64"
-	case "freebsd", "netbsd", "openbsd", "windows":
+	case "freebsd", "netbsd", "windows":
 		return goarch == "amd64"
 	default:
 		return false
@@ -192,6 +192,7 @@ func BuildModeSupported(compiler, buildmode, goos, goarch string) bool {
 			"darwin/amd64", "darwin/arm64",
 			"ios/amd64", "ios/arm64",
 			"aix/ppc64",
+			"openbsd/arm64",
 			"windows/386", "windows/amd64", "windows/arm", "windows/arm64":
 			return true
 		}

gofmt/internal/platform/zosarch.go

@@ -190,15 +190,13 @@ func findGOROOT() (string, error) {
 			// If runtime.GOROOT() is non-empty, assume that it is valid.
 			//
 			// (It might not be: for example, the user may have explicitly set GOROOT
-			// to the wrong directory, or explicitly set GOROOT_FINAL but not GOROOT
-			// and hasn't moved the tree to GOROOT_FINAL yet. But those cases are
+			// to the wrong directory. But this case is
 			// rare, and if that happens the user can fix what they broke.)
 			return
 		}
 
 		// runtime.GOROOT doesn't know where GOROOT is (perhaps because the test
-		// binary was built with -trimpath, or perhaps because GOROOT_FINAL was set
-		// without GOROOT and the tree hasn't been moved there yet).
+		// binary was built with -trimpath).
 		//
 		// Since this is internal/testenv, we can cheat and assume that the caller
 		// is a test of some package in a subdirectory of GOROOT/src. ('go test'
@@ -372,6 +370,15 @@ func MustInternalLink(t testing.TB, withCgo bool) {
 	}
 }
 
+// MustInternalLinkPIE checks whether the current system can link PIE binary using
+// internal linking.
+// If not, MustInternalLinkPIE calls t.Skip with an explanation.
+func MustInternalLinkPIE(t testing.TB) {
+	if !platform.InternalLinkPIESupported(runtime.GOOS, runtime.GOARCH) {
+		t.Skipf("skipping test: internal linking for buildmode=pie on %s/%s is not supported", runtime.GOOS, runtime.GOARCH)
+	}
+}
+
 // MustHaveBuildMode reports whether the current system can build programs in
 // the given build mode.
 // If not, MustHaveBuildMode calls t.Skip with an explanation.
@@ -505,3 +512,36 @@ func WriteImportcfg(t testing.TB, dstPath string, packageFiles map[string]string
 func SyscallIsNotSupported(err error) bool {
 	return syscallIsNotSupported(err)
 }
+
+// ParallelOn64Bit calls t.Parallel() unless there is a case that cannot be parallel.
+// This function should be used when it is necessary to avoid t.Parallel on
+// 32-bit machines, typically because the test uses lots of memory.
+func ParallelOn64Bit(t *testing.T) {
+	if goarch.PtrSize == 4 {
+		return
+	}
+	t.Parallel()
+}
+
+// CPUProfilingBroken returns true if CPU profiling has known issues on this
+// platform.
+func CPUProfilingBroken() bool {
+	switch runtime.GOOS {
+	case "plan9":
+		// Profiling unimplemented.
+		return true
+	case "aix":
+		// See https://golang.org/issue/45170.
+		return true
+	case "ios", "dragonfly", "netbsd", "illumos", "solaris":
+		// See https://golang.org/issue/13841.
+		return true
+	case "openbsd":
+		if runtime.GOARCH == "arm" || runtime.GOARCH == "arm64" {
+			// See https://golang.org/issue/13841.
+			return true
+		}
+	}
+
+	return false
+}

gofmt/internal/testenv/testenv.go

@@ -8,6 +8,7 @@
 
 ## Updates
 
+- 2025-04-14: Sync with go1.23.8
 - 2024-08-17: Sync with go1.22.6
 - 2023-02-28: Sync with go1.21.7
 - 2023-10-04: Sync with go1.20.8