cmd/go: allow -mlsx -mlasx cgo flags for loong64

[ideal]

Go version

go version go1.23.4 linux/loong64

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='loong64'
GOBIN=''
GOCACHE='/home/ideal/.cache/go-build'
GOENV='/home/ideal/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='loong64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/ideal/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/ideal/go'
GOPRIVATE=''
GOPROXY='https://goproxy.cn,direct'
GOROOT='/home/ideal/go/pkg/mod/golang.org/[email protected]'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/home/ideal/go/pkg/mod/golang.org/[email protected]/pkg/tool/linux_loong64'
GOVCS=''
GOVERSION='go1.23.4'
GODEBUG=''
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/ideal/.config/go/telemetry'
GCCGO='gccgo'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/home/ideal/project/ollama2/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -mabi=lp64d -pthread -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2938728940=/tmp/go-build -gno-record-gcc-switches'

What did you do?

With:

// #cgo linux,loong64 CFLAGS: -mlasx
// #cgo linux,loong64 CPPFLAGS: -mlasx

What did you see happen?

Running go build will show: invalid flag in #cgo CPPFLAGS: -mlasx.

But these are valid flags on loongarch64:

-mlasx
-mno-lasx
-mlsx
-mno-lsx

What did you expect to see?

go build succeeds.

[gabyhelp]

Related Issues

• cmd/go: invalid flag in #cgo LDFLAGS: -fopenmp #24858 (closed)
• cmd/go: allow passing -U flag in cgo CFLAGS #34730 (closed)
• cmd/go/internal/work/security.go: invalid flag in `#cgo LDFLAGS: -Wl,-rpath,.` #70924 (closed)
• cmd/go: allow invalid flag in #cgo LDFLAGS: CoreFoundation #43152 (closed)
• cmd/compile, cmd/link: c-shared not supported on linux/loong64 #53301 (closed)
• cmd/go: accept -Wl,-R,path #32167 (closed)
• cmd/cgo: after upgrade from 1.9.2 to 1.10, cgo compile fails with "invalid flag in #cgo LDFLAGS: -Wl,-z,relro" #24124 (closed)
• cmd/go/internal/work/security.go: invalid flag in `#cgo darwin LDFLAGS: -Wl,-rpath -Wl,@loader_path` #70923 (closed)
• The `go build` cross compilate failed #55033 (closed)
• affected/package: cgo #63206 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[seankhliao]

cc @golang/loong64

[cherrymui]

Seems reasonable. Feel free to send a CL (see the contribution guide). Thanks.

[xen0n]

There are more arch-specific flags described in the LoongArch Toolchain Conventions spec, so we would probably include all of them. Would you prepare a patch or leave it to the loong64 port team? Just in case you already have some CL prepared.

[ianlancetaylor]

FYI, the list of accepted flags is in the file $GOROOT/src/cmd/go/internal/work/security.go.

[gopherbot]

Change https://go.dev/cl/647956 mentions this issue: cmd/go/internal/work: allow a bunch of loong64-specific flags