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>
2026-05-01 03:09:49 +09:00
parent 2cd6b35bee
commit fc66f0bb47
10 changed files with 172 additions and 301 deletions
--- a/cmd/mbf/main.go
+++ b/cmd/mbf/main.go
@@ -318,7 +318,7 @@ func main() {

 				if err = cm.Do(func(cache *pkg.Cache) (err error) {
 					pathname, _, err = cache.Cure(
-						(t - 2).Load(rosa.Clang),
+						(t - 2).Load(rosa.LLVM),
 					)
 					return
 				}); err != nil {
@@ -328,7 +328,7 @@ func main() {

 				if err = cm.Do(func(cache *pkg.Cache) (err error) {
 					pathname, checksum[0], err = cache.Cure(
-						(t - 1).Load(rosa.Clang),
+						(t - 1).Load(rosa.LLVM),
 					)
 					return
 				}); err != nil {
@@ -337,7 +337,7 @@ func main() {
 				log.Println("stage2:", pathname)
 				if err = cm.Do(func(cache *pkg.Cache) (err error) {
 					pathname, checksum[1], err = cache.Cure(
-						t.Load(rosa.Clang),
+						t.Load(rosa.LLVM),
 					)
 					return
 				}); err != nil {
@@ -542,7 +542,7 @@ func main() {
 					presets[i] = p
 				}

-				base := rosa.Clang
+				base := rosa.LLVM
 				if !flagWithToolchain {
 					base = rosa.Musl
 				}
--- a/internal/rosa/all.go
+++ b/internal/rosa/all.go
@@ -16,9 +16,7 @@ import (
 type PArtifact int

 const (
-	CompilerRT PArtifact = iota
-	LLVMRuntimes
-	Clang
+	LLVM PArtifact = iota

 	// EarlyInit is the Rosa OS init program.
 	EarlyInit
@@ -77,7 +75,6 @@ const (
 	LibXau
 	Libbsd
 	Libcap
-	Libclc
 	Libdrm
 	Libev
 	Libexpat
@@ -174,12 +171,13 @@ const (
 	// PresetUnexportedStart is the first unexported preset.
 	PresetUnexportedStart

-	llvmSource = iota - 1
-	buildcatrust
+	buildcatrust = iota - 1
 	utilMacros

 	// Musl is a standalone libc that does not depend on the toolchain.
 	Musl
+	// muslHeaders is a system installation of [Musl] headers.
+	muslHeaders

 	// gcc is a hacked-to-pieces GCC toolchain meant for use in intermediate
 	// stages only. This preset and its direct output must never be exposed.
--- a/internal/rosa/llvm.go
+++ b/internal/rosa/llvm.go
@@ -1,195 +1,138 @@
 package rosa

-import "hakurei.app/internal/pkg"
+import (
+	"regexp"
+	"strings"

-func init() {
-	artifactsM[llvmSource] = Metadata{
-		f: func(t Toolchain) (pkg.Artifact, string) {
-			return t.NewPatchedSource("llvm", llvmVersion, newFromGitHub(
-				"llvm/llvm-project",
-				"llvmorg-"+llvmVersion,
-				llvmChecksum,
-			), true, llvmPatches...), llvmVersion
-		},
+	"hakurei.app/internal/pkg"
+)

-		Name:        "llvm-project",
-		Description: "LLVM monorepo with Rosa OS patches",
+func (t Toolchain) newLLVM() (pkg.Artifact, string) {
+	const (
+		version  = "22.1.4"
+		checksum = "Bk3t-tV5sD5T0bqefFMcLeFuAwXnhFipywZmqst5hAZs97QQWGKB_5XyAFjj5tDB"
+	)

-		ID: 1830,
-	}
-}
+	cache := []KV{
+		{"CMAKE_BUILD_TYPE", "Release"},

-func (t Toolchain) newCompilerRT() (pkg.Artifact, string) {
-	muslHeaders, _ := t.newMusl(true)
-	return t.NewPackage("compiler-rt", llvmVersion, t.Load(llvmSource), &PackageAttr{
-		NonStage0: []pkg.Artifact{
-			muslHeaders,
-		},
-		Env: stage0ExclConcat(t, []string{},
-			"LDFLAGS="+earlyLDFLAGS(false),
-		),
-		Flag: TExclusive,
-	}, &CMakeHelper{
-		Append: []string{"compiler-rt"},
+		{"ENABLE_LINKER_BUILD_ID", "ON"},
+		{"COMPILER_RT_USE_BUILTINS_LIBRARY", "ON"},
+		{"COMPILER_RT_DEFAULT_TARGET_ONLY", "ON"},
+		{"COMPILER_RT_BUILD_GWP_ASAN", "OFF"},
+		{"LIBCXX_CXX_ABI", "libcxxabi"},
+		{"LIBCXX_USE_COMPILER_RT", "ON"},
+		{"LIBCXX_ENABLE_STATIC_ABI_LIBRARY", "OFF"},
+		{"LIBCXX_HAS_MUSL_LIBC", "ON"},
+		{"LIBCXX_HARDENING_MODE", "fast"},
+		{"LIBCXXABI_USE_LLVM_UNWINDER", "ON"},
+		{"LIBCXXABI_ENABLE_STATIC_UNWINDER", "OFF"},
+		{"LIBCXXABI_USE_COMPILER_RT", "ON"},
+		{"LLVM_INSTALL_BINUTILS_SYMLINKS", "ON"},
+		{"LLVM_INSTALL_UTILS", "ON"},
+		{"LLVM_BUILD_LLVM_DYLIB", "ON"},
+		{"LLVM_LINK_LLVM_DYLIB", "ON"},
+		{"LLVM_APPEND_VC_REV", "OFF"},
+		{"LLVM_ENABLE_RTTI", "ON"},
+		{"LLVM_ENABLE_ZLIB", "FORCE_ON"},
+		{"LLVM_ENABLE_ZSTD", "FORCE_ON"},
+		{"LLVM_ENABLE_PER_TARGET_RUNTIME_DIR", "ON"},
+		{"CLANG_DEFAULT_RTLIB", "compiler-rt"},
+		{"CLANG_DEFAULT_UNWINDLIB", "libunwind"},
+		{"CLANG_DEFAULT_CXX_STDLIB", "libc++"},
+		{"CLANG_CONFIG_FILE_SYSTEM_DIR", "/system/etc/clang"},
+		{"LLVM_ENABLE_FFI", "OFF"},
+		{"LLVM_ENABLE_LIBXML2", "OFF"},
+		{"LLVM_ENABLE_LIBCXX", "ON"},
+		{"LLVM_ENABLE_LLD", "ON"},
+		{"LIBUNWIND_ENABLE_ASSERTIONS", "OFF"},
+		{"LIBUNWIND_USE_COMPILER_RT", "ON"},

-		Cache: []KV{
-			{"CMAKE_BUILD_TYPE", "Release"},
-
-			{"LLVM_HOST_TRIPLE", `"${ROSA_TRIPLE}"`},
-			{"LLVM_DEFAULT_TARGET_TRIPLE", `"${ROSA_TRIPLE}"`},
-
-			// libc++ not yet available
-			{"CMAKE_CXX_COMPILER_TARGET", ""},
-
-			{"COMPILER_RT_BUILD_BUILTINS", "ON"},
-			{"COMPILER_RT_DEFAULT_TARGET_ONLY", "OFF"},
-			{"COMPILER_RT_SANITIZERS_TO_BUILD", "asan"},
-			{"LLVM_ENABLE_PER_TARGET_RUNTIME_DIR", "ON"},
-
-			// does not work without libunwind
-			{"COMPILER_RT_BUILD_CTX_PROFILE", "OFF"},
-			{"COMPILER_RT_BUILD_LIBFUZZER", "OFF"},
-			{"COMPILER_RT_BUILD_MEMPROF", "OFF"},
-			{"COMPILER_RT_BUILD_PROFILE", "OFF"},
-			{"COMPILER_RT_BUILD_XRAY", "OFF"},
-		},
-		Script: `
-mkdir -p "/work/system/lib/clang/` + llvmVersionMajor + `/lib/"
-ln -s \
-	"../../../${ROSA_TRIPLE}" \
-	"/work/system/lib/clang/` + llvmVersionMajor + `/lib/"
-
-ln -s \
-	"clang_rt.crtbegin-` + linuxArch() + `.o" \
-	"/work/system/lib/${ROSA_TRIPLE}/crtbeginS.o"
-ln -s \
-	"clang_rt.crtend-` + linuxArch() + `.o" \
-	"/work/system/lib/${ROSA_TRIPLE}/crtendS.o"
-`,
-	},
-		Python,
-
-		KernelHeaders,
-	), llvmVersion
-}
-func init() {
-	artifactsM[CompilerRT] = Metadata{
-		f: Toolchain.newCompilerRT,
-
-		Name:        "compiler-rt",
-		Description: "LLVM runtime: compiler-rt",
-		Website:     "https://llvm.org/",
-
-		Dependencies: P{
-			Musl,
-		},
-	}
-}
-
-func (t Toolchain) newLLVMRuntimes() (pkg.Artifact, string) {
-	return t.NewPackage("llvm-runtimes", llvmVersion, t.Load(llvmSource), &PackageAttr{
-		NonStage0: t.AppendPresets(nil, CompilerRT),
-		Env: stage0ExclConcat(t, []string{},
-			"LDFLAGS="+earlyLDFLAGS(false),
-		),
-		Flag: TExclusive,
-	}, &CMakeHelper{
-		Append: []string{"runtimes"},
-
-		Cache: []KV{
-			{"CMAKE_BUILD_TYPE", "Release"},
-
-			{"LLVM_HOST_TRIPLE", `"${ROSA_TRIPLE}"`},
-			{"LLVM_DEFAULT_TARGET_TRIPLE", `"${ROSA_TRIPLE}"`},
-			{"LLVM_ENABLE_RUNTIMES", "'libunwind;libcxx;libcxxabi'"},
-
-			{"LIBUNWIND_USE_COMPILER_RT", "ON"},
-			{"LIBCXX_HAS_MUSL_LIBC", "ON"},
-			{"LIBCXX_USE_COMPILER_RT", "ON"},
-			{"LIBCXXABI_USE_COMPILER_RT", "ON"},
-			{"LIBCXXABI_USE_LLVM_UNWINDER", "ON"},
-
-			// libc++ not yet available
-			{"CMAKE_CXX_COMPILER_WORKS", "ON"},
-
-			{"LIBCXX_HAS_ATOMIC_LIB", "OFF"},
-			{"LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL", "OFF"},
-
-			{"LLVM_ENABLE_ZLIB", "OFF"},
-			{"LLVM_ENABLE_ZSTD", "OFF"},
-			{"LLVM_ENABLE_LIBXML2", "OFF"},
-		},
-	},
-		Python,
-
-		KernelHeaders,
-	), llvmVersion
-}
-func init() {
-	artifactsM[LLVMRuntimes] = Metadata{
-		f: Toolchain.newLLVMRuntimes,
-
-		Name:        "llvm-runtimes",
-		Description: "LLVM runtimes: libunwind, libcxx, libcxxabi",
-		Website:     "https://llvm.org/",
-
-		Dependencies: P{
-			CompilerRT,
-		},
-	}
-}
-
-func (t Toolchain) newClang() (pkg.Artifact, string) {
-	target := "'AArch64;RISCV;X86'"
-	if t.isStage0() {
-		target = "Native"
+		{"LLVM_HOST_TRIPLE", `"${ROSA_TRIPLE}"`},
+		{"LLVM_DEFAULT_TARGET_TRIPLE", `"${ROSA_TRIPLE}"`},
+		{"LLVM_ENABLE_PROJECTS", "'clang;lld;libclc'"},
+		{"LLVM_ENABLE_RUNTIMES", "'compiler-rt;libcxx;libcxxabi;libunwind'"},
 	}

-	return t.NewPackage("clang", llvmVersion, t.Load(llvmSource), &PackageAttr{
-		NonStage0: t.AppendPresets(nil, LLVMRuntimes),
-		Env: stage0ExclConcat(t, []string{},
-			"CFLAGS="+earlyCFLAGS,
-			"CXXFLAGS="+earlyCXXFLAGS(),
-			"LDFLAGS="+earlyLDFLAGS(false),
-		),
-		Flag: TExclusive,
-	}, &CMakeHelper{
+	if !t.isStage0() {
+		skipChecks := []string{
+			// expensive, pointless to run here
+			"benchmarks",
+			// LLVM ERROR: Tried to execute an unknown external function: roundevenf
+			"ExecutionEngine/Interpreter/intrinsics.ll",
+			// clang: deadlocks with LLVM_BUILD_LLVM_DYLIB
+			"crash-recovery-modules",
+			// clang: fatal error: '__config_site' file not found
+			"CodeGen/PowerPC/ppc-xmmintrin.c",
+			"CodeGen/PowerPC/ppc-mmintrin.c",
+			"CodeGen/PowerPC/ppc-emmintrin.c",
+			"CodeGen/PowerPC/ppc-pmmintrin.c",
+			"CodeGen/PowerPC/ppc-tmmintrin.c",
+			"CodeGen/PowerPC/ppc-smmintrin.c",
+			"CodeGenCUDA/amdgpu-alias-undef-symbols.cu",
+			// cxx: fails on musl
+			"close.dont-get-rid-of-buffer",
+			"re/re.traits",
+			"std/time",
+			"localization/locales",
+			"localization/locale.categories",
+			"selftest/dsl/dsl.sh.py",
+			"input.output/iostream.format",
+			"locale-specific_form",
+			// cxx: deadlocks
+			"std/thread/thread.jthread",
+			// unwind: fails on musl
+			"eh_frame_fde_pc_range",
+		}
+		for i, s := range skipChecks {
+			s = regexp.QuoteMeta(s)
+			s = strings.ReplaceAll(s, "/", "\\/")
+			skipChecks[i] = s
+		}
+
+		cache = append(cache, []KV{
+			// very expensive
+			{"LLVM_ENABLE_LTO", "Thin"},
+
+			// symbols: clock_gettime, mallopt
+			{"COMPILER_RT_INCLUDE_TESTS", "OFF"},
+
+			{"LLVM_LIT_ARGS", "'" + strings.Join([]string{
+				"--verbose",
+				"--filter-out='\\''" + strings.Join(skipChecks, "|") + "'\\''",
+			}, " ") + "'"},
+		}...)
+	}
+
+	return t.NewPackage("llvm", version, t.NewPatchedSource("llvm", version, newFromGitHub(
+		"llvm/llvm-project",
+		"llvmorg-"+version,
+		checksum,
+	), true, llvmPatches...), nil, &CMakeHelper{
 		Append: []string{"llvm"},

-		Cache: []KV{
-			{"CMAKE_BUILD_TYPE", "Release"},
-
-			{"LLVM_HOST_TRIPLE", `"${ROSA_TRIPLE}"`},
-			{"LLVM_DEFAULT_TARGET_TRIPLE", `"${ROSA_TRIPLE}"`},
-			{"LLVM_ENABLE_PROJECTS", "'clang;lld'"},
-
-			{"LLVM_ENABLE_LIBCXX", "ON"},
-			{"LLVM_USE_LINKER", "lld"},
-
-			{"LLVM_INSTALL_BINUTILS_SYMLINKS", "ON"},
-			{"LLVM_INSTALL_CCTOOLS_SYMLINKS", "ON"},
-
-			{"LLVM_LIT_ARGS", "'--verbose'"},
-
-			{"CLANG_DEFAULT_LINKER", "lld"},
-			{"CLANG_DEFAULT_CXX_STDLIB", "libc++"},
-			{"CLANG_DEFAULT_RTLIB", "compiler-rt"},
-			{"CLANG_DEFAULT_UNWINDLIB", "libunwind"},
-
-			{"LLVM_TARGETS_TO_BUILD", target},
-			{"CMAKE_CROSSCOMPILING", "OFF"},
-			{"CXX_SUPPORTS_CUSTOM_LINKER", "ON"},
-
-			{"LLVM_ENABLE_ZLIB", "OFF"},
-			{"LLVM_ENABLE_ZSTD", "OFF"},
-			{"LLVM_ENABLE_LIBXML2", "OFF"},
-		},
+		Cache: cache,
 		Script: `
 ln -s ld.lld /work/system/bin/ld

 ln -s clang /work/system/bin/cc
 ln -s clang++ /work/system/bin/c++
+`,

+		// LLVM_LINK_LLVM_DYLIB causes llvm test suite to leak system
+		// installation into test environment, and the tests end up testing the
+		// system installation instead. Tests are disabled on stage0 and relies
+		// on 3-stage determinism to test later stages.
+		SkipTest: t.isStage0(),
+
+		Test: `
+chmod +w /bin && ln -s \
+	../system/bin/chmod \
+	../system/bin/mkdir \
+	../system/bin/rm \
+	../system/bin/tr \
+	../system/bin/awk \
+	/bin
 ninja ` + jobsFlagE + ` check-all
 `,
 	},
@@ -201,44 +144,26 @@ ninja ` + jobsFlagE + ` check-all
 		Coreutils,
 		Findutils,

+		Zlib,
+		Zstd,
+		muslHeaders,
 		KernelHeaders,
-	), llvmVersion
+	), version
 }
 func init() {
-	artifactsM[Clang] = Metadata{
-		f: Toolchain.newClang,
+	artifactsM[LLVM] = Metadata{
+		f: Toolchain.newLLVM,

-		Name:        "clang",
-		Description: `an "LLVM native" C/C++/Objective-C compiler`,
-		Website:     "https://llvm.org/",
+		Name:        "llvm",
+		Description: "a collection of modular and reusable compiler and toolchain technologies",
+		Website:     "https://llvm.org",

 		Dependencies: P{
-			LLVMRuntimes,
+			Zlib,
+			Zstd,
+			Musl,
 		},
-	}
-}
-
-func (t Toolchain) newLibclc() (pkg.Artifact, string) {
-	return t.NewPackage("libclc", llvmVersion, t.Load(llvmSource), nil, &CMakeHelper{
-		Append: []string{"libclc"},
-
-		Cache: []KV{
-			{"CMAKE_BUILD_TYPE", "Release"},
-
-			{"LLVM_HOST_TRIPLE", `"${ROSA_TRIPLE}"`},
-			{"LLVM_DEFAULT_TARGET_TRIPLE", `"${ROSA_TRIPLE}"`},
-
-			{"LIBCLC_TARGETS_TO_BUILD", "all"},
-		},
-		Script: "ninja " + jobsFlagE + " test",
-	}), llvmVersion
-}
-func init() {
-	artifactsM[Libclc] = Metadata{
-		f: Toolchain.newLibclc,
-
-		Name:        "libclc",
-		Description: "an open source, BSD/MIT dual licensed implementation of the library requirements of the OpenCL C programming language",
-		Website:     "https://libclc.llvm.org/",
+
+		ID: 1830,
 	}
 }
--- a/internal/rosa/llvm_latest.go
+++ b/internal/rosa/llvm_latest.go
@@ -1,9 +0,0 @@
-package rosa
-
-// latest version of LLVM, conditional to temporarily avoid broken new releases
-const (
-	llvmVersionMajor = "22"
-	llvmVersion      = llvmVersionMajor + ".1.4"
-
-	llvmChecksum = "Bk3t-tV5sD5T0bqefFMcLeFuAwXnhFipywZmqst5hAZs97QQWGKB_5XyAFjj5tDB"
-)
--- a/internal/rosa/llvm_patches_latest.go
+++ b/internal/rosa/llvm_patches_latest.go
--- a/internal/rosa/mksh.go
+++ b/internal/rosa/mksh.go
@@ -7,9 +7,9 @@ func (t Toolchain) newMksh() (pkg.Artifact, string) {
 		version  = "59c"
 		checksum = "0Zj-k4nXEu3IuJY4lvwD2OrC2t27GdZj8SPy4DoaeuBRH1padWb7oREpYgwY8JNq"
 	)
-	return t.New("mksh-"+version, 0, stage0Concat(t, []pkg.Artifact{},
-		t.Load(Perl),
-		t.Load(Coreutils),
+	return t.New("mksh-"+version, 0, t.AppendPresets(nil,
+		Perl,
+		Coreutils,
 	), nil, []string{
 		"LDSTATIC=-static",
 		"CPPFLAGS=-DMKSH_DEFAULT_PROFILEDIR=\\\"/system/etc\\\"",
--- a/internal/rosa/musl.go
+++ b/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",
+	}
 }
--- 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)
--- a/internal/rosa/rosa_test.go
+++ b/internal/rosa/rosa_test.go
@@ -94,7 +94,7 @@ func TestCureAll(t *testing.T) {

 func BenchmarkStage3(b *testing.B) {
 	for b.Loop() {
-		rosa.Std.Load(rosa.Clang)
+		rosa.Std.Load(rosa.LLVM)

 		b.StopTimer()
 		rosa.DropCaches()
--- a/internal/rosa/stage0.go
+++ b/internal/rosa/stage0.go
@@ -9,9 +9,6 @@ import (
 func (t Toolchain) newStage0() (pkg.Artifact, string) {
 	return t.New("rosa-stage0", 0, []pkg.Artifact{
 		t.Load(Musl),
-		t.Load(CompilerRT),
-		t.Load(LLVMRuntimes),
-		t.Load(Clang),

 		t.Load(Zlib),
 		t.Load(Bzip2),