https://github.com/ziyao233 created https://github.com/llvm/llvm-project/pull/95848
crtbegin.o in compiler-rt contains weak reference to __cxa_finalize, which is implemented in libc. When building a shared library with --as-needed option, libc may be incorrectly marked as inactive, resulting in unresolved symbols in crtbegin.o This commit forces libc is linked with --no-as-needed option when using compiler-rt, fixing the problem. >From 515e09198c6d9da95df3357552cb7b41b03b6e8c Mon Sep 17 00:00:00 2001 From: Yao Zi <zi...@disroot.org> Date: Mon, 17 Jun 2024 19:49:24 +0000 Subject: [PATCH] [clang] force libc linked with --no-as-needed when using compiler-rt crtbegin.o in compiler-rt contains weak reference to __cxa_finalize, which is implemented in libc. When building a shared library with --as-needed option, libc may be incorrectly marked as inactive, resulting in unresolved symbols in crtbegin.o This commit forces libc is linked with --no-as-needed option when using compiler-rt, fixing the problem. Signed-off-by: Yao Zi <zi...@disroot.org> --- clang/lib/Driver/ToolChains/Gnu.cpp | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp index dedbfac6cb25d..419c6b6e43664 100644 --- a/clang/lib/Driver/ToolChains/Gnu.cpp +++ b/clang/lib/Driver/ToolChains/Gnu.cpp @@ -378,6 +378,7 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA, const bool HasCRTBeginEndFiles = ToolChain.getTriple().hasEnvironment() || (ToolChain.getTriple().getVendor() != llvm::Triple::MipsTechnologies); + const ToolChain::RuntimeLibType RLTType = ToolChain.GetRuntimeLibType(Args); ArgStringList CmdArgs; @@ -625,8 +626,15 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA, if (Args.hasArg(options::OPT_fsplit_stack)) CmdArgs.push_back("--wrap=pthread_create"); - if (!Args.hasArg(options::OPT_nolibc)) + if (!Args.hasArg(options::OPT_nolibc)) { + if (RLTType == ToolChain::RLT_CompilerRT) { + CmdArgs.push_back("--push-state"); + CmdArgs.push_back("--no-as-needed"); + } CmdArgs.push_back("-lc"); + if (RLTType == ToolChain::RLT_CompilerRT) + CmdArgs.push_back("--pop-state"); + } // Add IAMCU specific libs, if needed. if (IsIAMCU) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits