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>

1 files changed, 5 insertions, 52 deletions

diff --git a/internal/rosa/rosa.go b/internal/rosa/rosa.go
index c60e4568..e1d20407 100644
--- a/internal/rosa/rosa.go
+++ b/internal/rosa/rosa.go
@@ -107,21 +107,6 @@ func earlyLDFLAGS(static bool) string {
 	return s
 }
 
-// earlyCFLAGS is reference CFLAGS for the stage0 toolchain.
-const earlyCFLAGS = "-Qunused-arguments " +
-	"-isystem/system/include"
-
-// earlyCXXFLAGS returns reference CXXFLAGS for the stage0 toolchain
-// corresponding to [runtime.GOARCH].
-func earlyCXXFLAGS() string {
-	return "--start-no-unused-arguments " +
-		"-stdlib=libc++ " +
-		"--end-no-unused-arguments " +
-		"-isystem/system/include/c++/v1 " +
-		"-isystem/system/include/" + triplet() + "/c++/v1 " +
-		"-isystem/system/include "
-}
-
 // Toolchain denotes the infrastructure to compile a [pkg.Artifact] on.
 type Toolchain uint32
 
@@ -191,24 +176,6 @@ func (t Toolchain) isStd() bool {
 	}
 }
 
-// stage0Concat concatenates s and values. If the current toolchain is
-// toolchainStage0, stage0Concat returns s as is.
-func stage0Concat[S ~[]E, E any](t Toolchain, s S, values ...E) S {
-	if t.isStage0() {
-		return s
-	}
-	return slices.Concat(s, values)
-}
-
-// stage0ExclConcat concatenates s and values. If the current toolchain is not
-// toolchainStage0, stage0ExclConcat returns s as is.
-func stage0ExclConcat[S ~[]E, E any](t Toolchain, s S, values ...E) S {
-	if t.isStage0() {
-		return slices.Concat(s, values)
-	}
-	return s
-}
-
 // lastIndexFunc is like [strings.LastIndexFunc] but for [slices].
 func lastIndexFunc[S ~[]E, E any](s S, f func(E) bool) (i int) {
 	if i = slices.IndexFunc(s, f); i < 0 {
@@ -338,7 +305,7 @@ mkdir -vp /work/system/bin
 			toybox = toyboxEarly
 		}
 
-		base := Clang
+		base := LLVM
 		if flag&TNoToolchain != 0 {
 			base = Musl
 		}
@@ -353,11 +320,6 @@ mkdir -vp /work/system/bin
 		env = fixupEnviron(env, []string{
 			EnvTriplet + "=" + triplet(),
 			lcMessages,
-
-			"AR=ar",
-			"RANLIB=ranlib",
-			"LIBCC=/system/lib/clang/" + llvmVersionMajor + "/lib/" + triplet() +
-				"/libclang_rt.builtins.a",
 		}, "/system/bin", "/bin")
 
 	default:
@@ -415,8 +377,8 @@ cat /usr/src/` + name + `-patches/* | \
 `
 		aname += "-patched"
 	}
-	return t.New(aname, 0, stage0Concat(t, []pkg.Artifact{},
-		t.Load(Patch),
+	return t.New(aname, 0, t.AppendPresets(nil,
+		Patch,
 	), nil, nil, script, paths...)
 }
 
@@ -463,9 +425,6 @@ type PackageAttr struct {
 	// Passed to [Toolchain.NewPatchedSource].
 	Patches []KV
 
-	// Dependencies not provided by stage0.
-	NonStage0 []pkg.Artifact
-
 	// Passed through to [Toolchain.New], before source.
 	Paths []pkg.ExecPath
 	// Passed through to [Toolchain.New].
@@ -533,14 +492,8 @@ func (t Toolchain) NewPackage(
 		panic("source must be non-nil")
 	}
 	wantsChmod, wantsWrite := helper.wantsChmod(), helper.wantsWrite()
-	dc := len(attr.NonStage0)
-	if !t.isStage0() {
-		dc += 1<<3 + len(extra)
-	}
-
-	extraRes := make([]pkg.Artifact, 0, dc)
-	extraRes = append(extraRes, attr.NonStage0...)
-	if !t.isStage0() {
+	extraRes := make([]pkg.Artifact, 0, 1<<3+len(extra))
+	{
 		pv := paGet()
 		for _, p := range helper.extra(attr.Flag) {
 			extraRes = t.appendPreset(extraRes, pv, p)