https://github.com/ndrewh updated https://github.com/llvm/llvm-project/pull/161304
>From d03967ce6371f729b7f226d594f4380d4e025d80 Mon Sep 17 00:00:00 2001 From: Andrew Haberlandt <[email protected]> Date: Mon, 29 Sep 2025 18:12:24 -0700 Subject: [PATCH] [Darwin][Driver] Avoid duplicate -lc++ with -fsanitize=fuzzer On Darwin, duplicate -l options cause a warning to be printed. Invoking clang as clang++ and using -fsanitize=fuzzer will cause -lc++ to be passed twice to the linker, causing a warning. i.e. AddCXXStdlibLibArgs is called twice in this case: 1) https://github.com/llvm/llvm-project/blob/19c4e86f3e8582c3f087a9fec5ac036838e58ec4/clang/lib/Driver/ToolChains/Darwin.cpp#L743 2) The subject of this PR Since ShouldLinkCXXStdlib() implies that the linker will already get the -lc++ argument, we only add the argument if !ShouldLinkCXXStdlib(). rdar://136431775 --- clang/lib/Driver/ToolChains/Darwin.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp index 234683f2f4882..d2356ebdfa86c 100644 --- a/clang/lib/Driver/ToolChains/Darwin.cpp +++ b/clang/lib/Driver/ToolChains/Darwin.cpp @@ -1609,7 +1609,12 @@ void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args, if (Sanitize.needsFuzzer() && !Args.hasArg(options::OPT_dynamiclib)) { AddLinkSanitizerLibArgs(Args, CmdArgs, "fuzzer", /*shared=*/false); - // Libfuzzer is written in C++ and requires libcxx. + // Libfuzzer is written in C++ and requires libcxx. + // Since darwin::Linker::ConstructJob already adds -lc++ for clang++ + // by default if ShouldLinkCXXStdlib(Args), we only add the option if + // !ShouldLinkCXXStdlib(Args). This avoids duplicate library errors + // on Darwin. + if (!ShouldLinkCXXStdlib(Args)) AddCXXStdlibLibArgs(Args, CmdArgs); } if (Sanitize.needsStatsRt()) { _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
