cmd/dist: cross-compile via clang

The cross-compiled sysroot can now be provided by internal/rosa.
Unfortunately pkg-config still had to be configured externally to avoid
making any assumptions about the prefix.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 38 insertions, 9 deletions

diff --git a/cmd/dist/main.go b/cmd/dist/main.go
index 40a0583c..df586bbf 100644
--- a/cmd/dist/main.go
+++ b/cmd/dist/main.go
@@ -47,6 +47,22 @@ func mustRun(ctx context.Context, env []string, name string, arg ...string) {
 	}
 }
 
+// mustLinuxArch returns the architecture name used by linux corresponding to arch.
+func mustLinuxArch(arch string) string {
+	switch arch {
+	case "amd64":
+		return "x86_64"
+	case "arm64":
+		return "aarch64"
+	case "riscv64":
+		return "riscv64"
+
+	default:
+		log.Fatalf("unsupported target %s", arch)
+		return "\x00"
+	}
+}
+
 //go:embed comp/_hakurei
 var comp []byte
 
@@ -56,6 +72,8 @@ func main() {
 	log.SetOutput(os.Stdout)
 
 	verbose := os.Getenv("VERBOSE") != ""
+	arch := getenv("HAKUREI_ARCH", runtime.GOARCH)
+	sysroot := getenv("HAKUREI_SYSROOT", "/")
 	runTests := os.Getenv("HAKUREI_DIST_MAKE") == ""
 	race := os.Getenv("HAKUREI_RACE") != ""
 	dynamic := os.Getenv("HAKUREI_DYNAMIC") != ""
@@ -63,6 +81,9 @@ func main() {
 	prefix := getenv("PREFIX", "/usr/local")
 	destdir := getenv("DESTDIR", "dist")
 
+	linuxArch := mustLinuxArch(arch)
+	target := linuxArch + "-rosa-linux-musl"
+
 	if verbose {
 		log.Println()
 	}
@@ -71,10 +92,13 @@ func main() {
 		version += "-race"
 	}
 
-	if err := os.Setenv("CC", "clang"); err != nil {
-		log.Fatal(err)
-	} else if err = os.Setenv("CXX", "clang++"); err != nil {
-		log.Fatal(err)
+	for _, env := range [][2]string{
+		{"CC", "clang --target=" + target + " --sysroot=" + sysroot},
+		{"CXX", "clang++ --target=" + target + " --sysroot=" + sysroot},
+	} {
+		if err := os.Setenv(env[0], env[1]); err != nil {
+			log.Fatal(err)
+		}
 	}
 
 	if err := os.MkdirAll(destdir, 0755); err != nil {
@@ -134,10 +158,12 @@ func main() {
 		ldflagsStatic = ""
 	}
 
-	log.Printf("Building hakurei %s for %s/%s.", version, runtime.GOOS, runtime.GOARCH)
+	log.Printf("Building hakurei %s for %s/%s.", version, runtime.GOOS, arch)
 	mustRun(ctx, nil, "go", "generate", "./...")
 	mustRun(
-		ctx, nil, "go", "build",
+		ctx, []string{
+			"GOARCH=" + arch,
+		}, "go", "build",
 		"-trimpath",
 		verboseFlag, raceFlag, "-o", s,
 		"-ldflags=-s -w "+
@@ -149,9 +175,12 @@ func main() {
 		"./cmd/sharefs",
 	)
 
-	log.Printf("Building cmd/hsu for %s/%s.", runtime.GOOS, runtime.GOARCH)
+	log.Printf("Building cmd/hsu for %s/%s.", runtime.GOOS, arch)
 	mustRun(
-		ctx, []string{"CGO_ENABLED=0"}, "go", "build",
+		ctx, []string{
+			"CGO_ENABLED=0",
+			"GOARCH=" + arch,
+		}, "go", "build",
 		"-trimpath",
 		verboseFlag, "-o", s,
 		"-ldflags=-s -w "+
@@ -173,7 +202,7 @@ func main() {
 
 	log.Println("##### Creating distribution.")
 	const suffix = ".tar.gz"
-	distName := "hakurei-" + version + "-" + runtime.GOARCH
+	distName := "hakurei-" + version + "-" + arch
 	var f *os.File
 	if f, err = os.OpenFile(
 		filepath.Join(s, distName+suffix),