cmd,runtime: enable race detector on loong64

The race feature depends on llvm. And support for building the tsan library on
linux/loong64 has been added in this patch [1], which has been merged into the
branch main and has landed in llvm18.

The support for linux/loong64 in racebuild has been implemented in CL 655775,
now racebuild can successfully build race_linux_loong64.syso [2].

[1]: llvm/llvm-project#72819
[2]: racebuild -platforms linux/loong64 -cherrypick 'refs/changes/16/543316/10' \
     -rev 83fe85115da9dc25fa270d2ea8140113c8d49670 \
     -goroot /home/golang/src/go

Co-authored-by: Xiaolin Zhao <[email protected]>

Change-Id: If389318215476890295ed771297c6c088cfc84b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/543316
Reviewed-by: Qiqi Huang <[email protected]>
Reviewed-by: Junyang Shao <[email protected]>
Auto-Submit: Michael Pratt <[email protected]>
Reviewed-by: Meidan Li <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Mauri de Souza Meneguzzo <[email protected]>
Reviewed-by: Michael Pratt <[email protected]>
Reviewed-by: sophie zhao <[email protected]>

Author: abner-chenc

src/cmd/dist/test.go

@@ -1678,7 +1678,7 @@ func (t *tester) makeGOROOTUnwritable() (undo func()) {
 func raceDetectorSupported(goos, goarch string) bool {
 	switch goos {
 	case "linux":
-		return goarch == "amd64" || goarch == "ppc64le" || goarch == "arm64" || goarch == "s390x"
+		return goarch == "amd64" || goarch == "ppc64le" || goarch == "arm64" || goarch == "s390x" || goarch == "loong64"
 	case "darwin":
 		return goarch == "amd64" || goarch == "arm64"
 	case "freebsd", "netbsd", "windows":

src/internal/platform/supported.go

@@ -23,7 +23,7 @@ func (p OSArch) String() string {
 func RaceDetectorSupported(goos, goarch string) bool {
 	switch goos {
 	case "linux":
-		return goarch == "amd64" || goarch == "ppc64le" || goarch == "arm64" || goarch == "s390x"
+		return goarch == "amd64" || goarch == "ppc64le" || goarch == "arm64" || goarch == "s390x" || goarch == "loong64"
 	case "darwin":
 		return goarch == "amd64" || goarch == "arm64"
 	case "freebsd", "netbsd", "windows":

src/race.bash

@@ -9,7 +9,7 @@
 set -e
 
 function usage {
-	echo 'race detector is only supported on linux/amd64, linux/ppc64le, linux/arm64, linux/s390x, freebsd/amd64, netbsd/amd64, openbsd/amd64, darwin/amd64, and darwin/arm64' 1>&2
+	echo 'race detector is only supported on linux/amd64, linux/ppc64le, linux/arm64, linux/loong64, linux/s390x, freebsd/amd64, netbsd/amd64, openbsd/amd64, darwin/amd64, and darwin/arm64' 1>&2
 	exit 1
 }
 
@@ -19,6 +19,7 @@ case $(uname -s -m) in
   "Linux x86_64")  ;;
   "Linux ppc64le") ;;
   "Linux aarch64") ;;
+  "Linux loongarch64") ;;
   "Linux s390x")   ;;
   "FreeBSD amd64") ;;
   "NetBSD amd64")  ;;

src/runtime/asm_loong64.s

@@ -37,6 +37,7 @@ TEXT runtime·rt0_go(SB),NOSPLIT|TOPFRAME,$0
 	JAL	(R25)
 
 nocgo:
+	JAL	runtime·save_g(SB)
 	// update stackguard after _cgo_init
 	MOVV	(g_stack+stack_lo)(g), R19
 	ADDV	$const_stackGuard, R19

src/runtime/race/README

@@ -13,5 +13,6 @@ internal/amd64v1/race_windows.syso built with LLVM 51bfeff0e4b0757ff773da6882f4d
 internal/amd64v3/race_linux.syso built with LLVM 51bfeff0e4b0757ff773da6882f4d538996c9b04 and Go e7d582b55dda36e76ce4d0ce770139ca0915b7c5.
 race_darwin_arm64.syso built with LLVM 51bfeff0e4b0757ff773da6882f4d538996c9b04 and Go e7d582b55dda36e76ce4d0ce770139ca0915b7c5.
 race_linux_arm64.syso built with LLVM 51bfeff0e4b0757ff773da6882f4d538996c9b04 and Go e7d582b55dda36e76ce4d0ce770139ca0915b7c5.
+race_linux_loong64.syso built with LLVM 83fe85115da9dc25fa270d2ea8140113c8d49670 and Go 037112464b4439571b45536de9ebe4bc9e10ecb7.
 race_linux_ppc64le.syso built with LLVM 51bfeff0e4b0757ff773da6882f4d538996c9b04 and Go e7d582b55dda36e76ce4d0ce770139ca0915b7c5.
 race_linux_s390x.syso built with LLVM 51bfeff0e4b0757ff773da6882f4d538996c9b04 and Go e7d582b55dda36e76ce4d0ce770139ca0915b7c5.

src/runtime/race/race.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build race && ((linux && (amd64 || arm64 || ppc64le || s390x)) || ((freebsd || netbsd || openbsd || windows) && amd64))
+//go:build race && ((linux && (amd64 || arm64 || loong64 || ppc64le || s390x)) || ((freebsd || netbsd || openbsd || windows) && amd64))
 
 package race