build other runtime components to avoid any system code in our runtim…

…e dependencies

cross-build-compiler-rt.sh → cross-build-libunwind.sh

@@ -1,20 +1,22 @@
 #!/bin/sh
+# build compiler-rt, libcxx, libcxxabi, and libunwind with our patched clang
 # see https://llvm.org/docs/HowToCrossCompileBuiltinsOnArm.html
-mkdir -p build-compiler-rt
-cd build-compiler-rt
-cross_flags="--gcc-toolchain=/usr -isystem /usr/aarch64-linux-gnu/include -march=armv8.5-a+memtag -ffixed-x18"
+mkdir -p build-rtlibs
+cd build-rtlibs
+cross_flags="--sysroot=/usr/aarch64-linux-gnu/ --gcc-install-dir=/usr/lib/gcc/aarch64-linux-gnu/14.1.0 --rtlib=compiler-rt -march=armv8+memtag -ffixed-x18"
 export LDFLAGS="-L/usr/aarch64-linux-gnu/lib"
 cmake -GNinja -DLLVM_TARGETS_TO_BUILD="AArch64" -DLLVM_DEFAULT_TARGET_TRIPLE="aarch64-linux-gnu" \
     -DCMAKE_BUILD_TYPE=RelWithDebInfo \
     -DCMAKE_C_FLAGS="$cross_flags --target=aarch64-linux-gnu" -DCMAKE_CXX_FLAGS="$cross_flags --target=aarch64-linux-gnu" \
     -DCMAKE_C_COMPILER="$(pwd)/../build/bin/clang" -DCMAKE_CXX_COMPILER="$(pwd)/../build/bin/clang" \
     -DCMAKE_BUILD_WITH_INSTALL_RPATH=true \
-    -DCOMPILER_RT_BUILD_SANITIZERS=OFF -DCOMPILER_RT_BUILD_MEMPROF=OFF -DCOMPILER_RT_BUILD_ORC=OFF \
-    -DCOMPILER_RT_BUILD_XRAY=OFF -DCOMPILER_RT_BUILD_LIBFUZZER=OFF \
-    -DCOMPILER_RT_DEFAULT_TARGET_TRIPLE="aarch64-linux-gnu" \
-    ../compiler-rt
+    -DCMAKE_EXE_LINKER_FLAGS='--rtlib=compiler-rt' \
+    -DCOMPILER_RT_BUILD_BUILTINS=ON \
+    -DLIBCXX_USE_COMPILER_RT=YES \
+    -DLLVM_ENABLE_RUNTIMES='libcxx;libcxxabi;compiler-rt;libunwind' \
+    ../runtimes
 ninja
-cd lib/linux
+cd compiler-rt/lib/linux
 # rename CRT files to expected filenames
 cp -a clang_rt.crtend-aarch64.o crtendS.o
 cp -a clang_rt.crtbegin-aarch64.o crtbeginS.o