internal/rosa/llvm: use llvm build system

This removes the multistep bootstrap hack. Stage0 exceptions are also eliminated for a later change to bring the stage0 distribution down to just a bare toolchain, toybox and shell. This change also enables dynamic linking and ThinLTO.

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

internal/rosa/musl.go

@@ -2,10 +2,7 @@ package rosa
 
 import "hakurei.app/internal/pkg"
 
-func (t Toolchain) newMusl(
-	headers bool,
-	extra ...pkg.Artifact,
-) (pkg.Artifact, string) {
+func (t Toolchain) newMusl(headers bool) (pkg.Artifact, string) {
 	const (
 		version  = "1.2.6"
 		checksum = "WtWb_OV_XxLDAB5NerOL9loLlHVadV00MmGk65PPBU1evaolagoMHfvpZp_vxEzS"
@@ -36,25 +33,26 @@ rmdir -v /work/lib
 		helper.Script = ""
 	}
 
+	env := []string{
+		"LDFLAGS=" + earlyLDFLAGS(false),
+	}
+	if t.isStage0() {
+		env = append(env,
+			"CC=clang",
+			"AR=ar",
+			"RANLIB=ranlib",
+		)
+	}
+
 	return t.NewPackage(name, version, newTar(
 		"https://musl.libc.org/releases/musl-"+version+".tar.gz",
 		checksum,
 		pkg.TarGzip,
 	), &PackageAttr{
-		NonStage0: extra,
-
 		// expected to be writable in copies
 		Chmod: true,
 
-		Env: stage0ExclConcat(t, []string{
-			"CC=clang",
-			"LIBCC=/system/lib/clang/" + llvmVersionMajor + "/lib/" +
-				triplet() + "/libclang_rt.builtins.a",
-			"AR=ar",
-			"RANLIB=ranlib",
-		},
-			"LDFLAGS="+earlyLDFLAGS(false),
-		),
+		Env: env,
 	}, &helper,
 		Coreutils,
 	), version
@@ -62,7 +60,7 @@ rmdir -v /work/lib
 func init() {
 	artifactsM[Musl] = Metadata{
 		f: func(t Toolchain) (pkg.Artifact, string) {
-			return t.newMusl(false, t.Load(CompilerRT))
+			return t.newMusl(false)
 		},
 
 		Name:        "musl",
@@ -71,4 +69,13 @@ func init() {
 
 		ID: 11688,
 	}
+
+	artifactsM[muslHeaders] = Metadata{
+		f: func(t Toolchain) (pkg.Artifact, string) {
+			return t.newMusl(true)
+		},
+
+		Name:        "musl-headers",
+		Description: "system installation of musl headers",
+	}
 }