Hi, When I emerged clang & friends with clang-common[default-compiler-rt,default-libcxx], I notice that the libraries from the package compiler-rt-sanitizers were still linked to libgcc_s.so.1 and libstdc++.so.6. This seems to be caused by the CMakefile that includes -nodefaultlibs (therefore the settings stored in /etc/clang/gentoo-runtimes.cfg are not used). Reproducible: Always Steps to Reproduce: 1. Emerge clang-common with USE="default-compiler-rt default-libcxx" 2. Check how the libraries are linked: ldd $(qlist compiler-rt-sanitizers | grep -E '.so$') 3. Libraries are linked to libgcc_s.so.1 and libstdc++.so.6 (and not to libc++abi.so.1) Actual Results: Libraries linked to libgcc_s.so.1 and libstdc++.so.6 Expected Results: Libraries linked to libc++abi.so.1 The following (naive?) patch to the ebuild gives the expected behavior: diff -u /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild --- /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild 2024-12-11 13:28:52.000000000 +0100 +++ /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild 2024-12-15 00:43:28.458403776 +0100 @@ -118,6 +118,7 @@ local -x CC=${CHOST}-clang local -x CXX=${CHOST}-clang++ strip-unsupported-flags + local -x CXXFLAGS="${CXXFLAGS} -stdlib=libc++" fi local flag want_sanitizer=OFF @@ -138,6 +139,7 @@ # builtins & crt installed by llvm-runtimes/compiler-rt -DCOMPILER_RT_BUILD_BUILTINS=OFF -DCOMPILER_RT_BUILD_CRT=OFF + -DCOMPILER_RT_USE_BUILTINS_LIBRARY=$(grep -q '^--rtlib=compiler-rt' /etc/clang/gentoo-runtimes.cfg && echo 'YES' || echo 'NO') -DCOMPILER_RT_BUILD_CTX_PROFILE=$(usex ctx-profile) -DCOMPILER_RT_BUILD_LIBFUZZER=$(usex libfuzzer) -DCOMPILER_RT_BUILD_MEMPROF=$(usex memprof)
I can reproduce this on ppc64 and the patch works.
apologies, as I was mainly looking to make my fix work this patch will work better for users who don't choose to have libcxx (added check before adding -stdlib=libc++ in CXXFLAGS) I also added some comments The modified flags are picked up by the CMakefile to trigger the desired linking diff -u /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild --- /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild 2024-12-11 13:28:52.000000000 +0100 +++ /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild 2024-12-15 19:33:59.753376360 +0100 @@ -118,6 +118,12 @@ local -x CC=${CHOST}-clang local -x CXX=${CHOST}-clang++ strip-unsupported-flags + + # check for llvm-core/clang-common[default-libcxx] + grep -qs '^--stdlib=libc++' /etc/clang/gentoo-runtimes.cfg + if [ $? -eq 0 ]; then + local -x CXXFLAGS="${CXXFLAGS} -stdlib=libc++" + fi fi local flag want_sanitizer=OFF @@ -138,6 +144,8 @@ # builtins & crt installed by llvm-runtimes/compiler-rt -DCOMPILER_RT_BUILD_BUILTINS=OFF -DCOMPILER_RT_BUILD_CRT=OFF + # check for llvm-core/clang-common[default-compiler-rt] + -DCOMPILER_RT_USE_BUILTINS_LIBRARY=$(grep -q '^--rtlib=compiler-rt' /etc/clang/gentoo-runtimes.cfg && echo 'YES' || echo 'NO') -DCOMPILER_RT_BUILD_CTX_PROFILE=$(usex ctx-profile) -DCOMPILER_RT_BUILD_LIBFUZZER=$(usex libfuzzer) -DCOMPILER_RT_BUILD_MEMPROF=$(usex memprof)
(In reply to Stef Simoens from comment #2) > apologies, as I was mainly looking to make my fix work > this patch will work better for users who don't choose to have libcxx (added > check before adding -stdlib=libc++ in CXXFLAGS) > I also added some comments > > The modified flags are picked up by the CMakefile to trigger the desired > linking > > diff -u > /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt- > sanitizers-19.1.4.ebuild > /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt- > sanitizers-19.1.4.ebuild > --- > /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt- > sanitizers-19.1.4.ebuild 2024-12-11 13:28:52.000000000 +0100 > +++ > /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt- > sanitizers-19.1.4.ebuild 2024-12-15 19:33:59.753376360 +0100 > @@ -118,6 +118,12 @@ > local -x CC=${CHOST}-clang > local -x CXX=${CHOST}-clang++ > strip-unsupported-flags > + > + # check for llvm-core/clang-common[default-libcxx] > + grep -qs '^--stdlib=libc++' /etc/clang/gentoo-runtimes.cfg > + if [ $? -eq 0 ]; then > + local -x CXXFLAGS="${CXXFLAGS} -stdlib=libc++" > + fi We should use tc-get-cxx-stdlib from toolchain-funcs.eclass. > fi > > local flag want_sanitizer=OFF > @@ -138,6 +144,8 @@ > # builtins & crt installed by llvm-runtimes/compiler-rt > -DCOMPILER_RT_BUILD_BUILTINS=OFF > -DCOMPILER_RT_BUILD_CRT=OFF > + # check for llvm-core/clang-common[default-compiler-rt] > + -DCOMPILER_RT_USE_BUILTINS_LIBRARY=$(grep -q > '^--rtlib=compiler-rt' /etc/clang/gentoo-runtimes.cfg && echo 'YES' || echo > 'NO') Ditto tc-get-c-rtlib. > -DCOMPILER_RT_BUILD_CTX_PROFILE=$(usex ctx-profile) > -DCOMPILER_RT_BUILD_LIBFUZZER=$(usex libfuzzer) > -DCOMPILER_RT_BUILD_MEMPROF=$(usex memprof)
you mean like this? (tested and works for my config) FYI to give transparency regarding why these flags are modified, these are the relevant config from the CMakeLists.txt # in CMakeLists.txt: -nostdlib is added, and an alternative way of including the library to link to is selected # macro(handle_default_cxx_lib var) # # Specifying -stdlib= in CMAKE_CXX_FLAGS overrides the defaults. # if (CMAKE_CXX_FLAGS MATCHES "-stdlib=([a-zA-Z+]*)") # set(${var}_LIBNAME "${CMAKE_MATCH_1}") # set(${var}_SYSTEM 1) # (...) # # likewise for gcc_s # if (COMPILER_RT_USE_BUILTINS_LIBRARY) # string(REPLACE "-Wl,-z,defs" "" CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}") # else() # if (ANDROID) # append_list_if(COMPILER_RT_HAS_GCC_LIB gcc SANITIZER_COMMON_LINK_LIBS) # else() # append_list_if(COMPILER_RT_HAS_GCC_S_LIB gcc_s SANITIZER_COMMON_LINK_LIBS) # endif() # endif() diff -u /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild --- /var/db/repos/gentoo/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild 2024-12-11 13:28:52.000000000 +0100 +++ /usr/local/portage/llvm-runtimes/compiler-rt-sanitizers/compiler-rt-sanitizers-19.1.4.ebuild 2024-12-15 20:33:03.312575993 +0100 @@ -118,6 +118,9 @@ local -x CC=${CHOST}-clang local -x CXX=${CHOST}-clang++ strip-unsupported-flags + + # link to libc++ + local -x CXXFLAGS="${CXXFLAGS} -stdlib=$(tc-get-cxx-stdlib)" fi local flag want_sanitizer=OFF @@ -128,6 +131,10 @@ fi done + # link to compiler-rt + local use_compiler_rt=OFF + [[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON + local mycmakeargs=( -DCOMPILER_RT_INSTALL_PATH="${EPREFIX}/usr/lib/clang/${LLVM_MAJOR}" # use a build dir structure consistent with install @@ -138,6 +145,7 @@ # builtins & crt installed by llvm-runtimes/compiler-rt -DCOMPILER_RT_BUILD_BUILTINS=OFF -DCOMPILER_RT_BUILD_CRT=OFF + -DCOMPILER_RT_USE_BUILTINS_LIBRARY=${use_compiler_rt} -DCOMPILER_RT_BUILD_CTX_PROFILE=$(usex ctx-profile) -DCOMPILER_RT_BUILD_LIBFUZZER=$(usex libfuzzer) -DCOMPILER_RT_BUILD_MEMPROF=$(usex memprof)
