mrustc: init

This bootstraps rustc via the mrustc alternative compiler. The build process is extraordinarily ugly because rustc maintainers cargo culted target triple strings without understanding what they are, and completely mishandles them. They also appear to lack fundamental system understanding and assume musl can only be used for static linking. The build process also fails to populate their so called self-contained library directory, so it is manually put together here. This setup uses the vendored LLVM for multiple reasons: the fact that rustc maintainers manage to fuck up so badly they simultaneously pass GCC-only and Clang-only flags when using an LLVM configured to use libc++ instead of GNU slop, and the immense maintenance burden to keep this up to date enough to use Rosa OS LLVM. For now, time and effort saved from trying to mutilate this pile of garbage into working with a proper LLVM build more than compensates for the wasted CPU time. GCC libraries are included in the output because despite the utter reluctance to do dynamic linking correctly on musl, it seems that rustc is also incapable of passing the correct linker flags to produce static executables, and the miserable mrustc Makefiles make it impossible to specify custom linker flags. From my previous experience producing a static virtiofsd build, it would require multiple arguments per library, all of them in rustc's fucked up custom syntax, and I am not ready to deal with that. To avoid contaminating future stages with gcc, this package includes only libraries required at runtime. Signed-off-by: Ophestra <cat@gensokyo.uk>
2026-07-23 00:50:24 +09:00
parent a1b0a10fcf
commit ce971c7651
6 changed files with 2388 additions and 0 deletions
@@ -0,0 +1,54 @@
+diff --git a/run_rustc/Makefile b/run_rustc/Makefile
+index e78d8c51..cc9f785e 100644
+--- a/run_rustc/Makefile
+++ b/run_rustc/Makefile
+@@ -150,14 +150,23 @@ $(CARGO_HOME)config: Makefile
+ 	$Vecho "[source.vendored-sources]" >> $@
+ 	$Vecho "directory = \"$(abspath $(VENDOR_DIR))\"" >> $@
+ 
+self-contained:
+	mkdir -p $@
+	(set -o braceexpand && ln -s \
+		/system/lib/{'rcrt1.o','crti.o','crtn.o'} \
+		/system/lib/gcc/"$(ROSA_TRIPLE)"/"$(shell gcc -dumpfullversion)"/{'crtbeginS.o','crtendS.o'} \
+		/system/lib/"$(ROSA_TRIPLE)"/* \
+		$@)
+
+ # -------------------------------------
+ # Stage 1: Build standard library (using minicargo with rustc)
+ # - Can't use `cargo` because there isn't a rustc-compatible std yet
+ # - _could_ use it if mrustc accepted all the arguments rustc does (via the proxy)
+ # -------------------------------------
+-$(LIBDIR_S)libstd.rlib: $(BINDIR_S)rustc $(MINICARGO) Makefile
+$(LIBDIR_S)libstd.rlib: self-contained $(BINDIR_S)rustc $(MINICARGO) Makefile
+ 	@echo "[MINICARGO] $(RUST_SRC_LIBS)std > $(LIBDIR_S)"
+-	mkdir -p $(LIBDIR_S)
+	@mkdir -p $(LIBDIR_S)
+	@ln -sf ../../../../../../self-contained $(LIBDIR_S)
+ ifneq ($(TARGETVER_LEAST_1_74),)
+ 	$V+STD_ENV_ARCH=$(RUSTC_ARCH) MRUSTC_PATH=$(abspath $(BINDIR_S)rustc) $(MINICARGO) --vendor-dir $(VENDOR_DIR) --script-overrides ../script-overrides/stable-$(RUSTC_VERSION)-$(PLATFORM)/ --output-dir $(LIBDIR_S) $(RUST_SRC_LIBS)sysroot
+ else
+@@ -178,6 +187,7 @@ CARGO_OUTDIR_STAGE2_STD := $(OUTDIR)build-std2/$(RUSTC_TARGET)/release/
+ CARGO_ENV_STAGE2_STD := CARGO_TARGET_DIR=$(OUTDIR)build-std2 RUSTC=$(abspath rustc_proxy.sh) PROXY_RUSTC=$(abspath $(BINDIR_2)rustc) PROXY_MRUSTC=$(abspath $(BINDIR_S)rustc) $(CARGO_ENV)
+ $(LIBDIR_2)libtest.rlib: $(LIBDIR_S)libstd.rlib $(BINDIR_2)rustc $(BINDIR_S)rustc $(BINDIR_S)cargo $(CARGO_HOME)config Makefile
+ 	@mkdir -p $(LIBDIR_2)
+	@ln -sf ../../../../../../self-contained $(LIBDIR_2)
+ 	@echo [CARGO] $(RUST_SRC_LIBS)test/Cargo.toml '>' $(OUTDIR)build-std2
+ ifneq ($(TARGETVER_LEAST_1_74),)
+ 	$V$(CARGO_ENV_STAGE2_STD) $(BINDIR_S)cargo build $(CARGO_FLAGS) --manifest-path $(RUST_SRC_LIBS)sysroot/Cargo.toml --features panic-unwind
+@@ -215,6 +225,7 @@ else
+ 	@echo "[CP] libraries and results ($@)"
+ endif
+ 	@mkdir -p $(LIBDIR)
+	@ln -sf ../../../../../../self-contained $(LIBDIR)
+ 	$Vcp $(LIBDIR_2)*.$(DYLIB_EXT) $(PREFIX)lib
+ 	$Vcp $(CARGO_OUTDIR_RUSTC)deps/*.rlib $(LIBDIR)
+ 	$Vcp $(CARGO_OUTDIR_RUSTC)deps/*.$(DYLIB_EXT) $(LIBDIR)
+@@ -243,6 +254,7 @@ CARGO_OUTDIR_STAGE3_STD := $(OUTDIR)build-std/$(RUSTC_TARGET)/release/
+ CARGO_ENV_STAGE3_STD := CARGO_TARGET_DIR=$(OUTDIR)build-std RUSTC=$(abspath rustc_proxy.sh) PROXY_RUSTC=$(abspath $(BINDIR)rustc) PROXY_MRUSTC=$(abspath $(BINDIR_2)rustc) $(CARGO_ENV)
+ $(LIBDIR)libstd.rlib: $(BINDIR)rustc
+ 	@mkdir -p $(LIBDIR)
+	@ln -sf ../../../../../../self-contained $(LIBDIR)
+ 	@echo [CARGO] $(RUST_SRC_LIBS)test/Cargo.toml '>' $(OUTDIR)build-std2
+ ifneq ($(TARGETVER_LEAST_1_74),)
+ 	$V$(CARGO_ENV_STAGE3_STD) $(BINDIR_S)cargo build $(CARGO_FLAGS) --manifest-path $(RUST_SRC_LIBS)sysroot/Cargo.toml --features panic-unwind