From 7e7dd47fc21daf11c12484f4e9c4585b70d91560 Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Sat, 7 Mar 2015 10:01:29 +0000 Subject: [PATCH] Much like we silence warnings about -flto in many cases to facilitate simplicity in build systems, silence '-stdlib=libc++' when linking. Even if we're not linking C++ code per-se, we may be passing this flag so that when we are linking C++ code we pick up the desired standard library. While most build systems already provide separate C and C++ compile flags, many conflate link flags. Sadly, CMake is among them causing this warning in a libc++ selfhost. llvm-svn: 231559 --- clang/lib/Driver/Tools.cpp | 2 ++ clang/test/Driver/linux-ld.c | 17 +++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp index a80214e1e663..3c6827af9d8a 100644 --- a/clang/lib/Driver/Tools.cpp +++ b/clang/lib/Driver/Tools.cpp @@ -7704,6 +7704,8 @@ void gnutools::Link::ConstructJob(Compilation &C, const JobAction &JA, CmdArgs.push_back("-Bdynamic"); CmdArgs.push_back("-lm"); } + // Silence warnings when linking C code with a C++ '-stdlib' argument. + Args.ClaimAllArgs(options::OPT_stdlib_EQ); if (!Args.hasArg(options::OPT_nostdlib)) { if (!Args.hasArg(options::OPT_nodefaultlibs)) { diff --git a/clang/test/Driver/linux-ld.c b/clang/test/Driver/linux-ld.c index f2e6eda3ffb4..a16c36ab3d51 100644 --- a/clang/test/Driver/linux-ld.c +++ b/clang/test/Driver/linux-ld.c @@ -417,6 +417,23 @@ // CHECK-BASIC-LIBCXX-INSTALL: "--sysroot=[[SYSROOT]]" // CHECK-BASIC-LIBCXX-INSTALL: "-L[[SYSROOT]]/usr/bin/../lib" // +// Test that we can use -stdlib=libc++ in a build system even when it +// occasionally links C code instead of C++ code. +// RUN: %clang -no-canonical-prefixes -x c %s -### -o %t.o 2>&1 \ +// RUN: -target x86_64-unknown-linux-gnu \ +// RUN: -stdlib=libc++ \ +// RUN: -ccc-install-dir %S/Inputs/basic_linux_libcxx_tree/usr/bin \ +// RUN: --gcc-toolchain="" \ +// RUN: --sysroot=%S/Inputs/basic_linux_libcxx_tree \ +// RUN: | FileCheck --check-prefix=CHECK-BASIC-LIBCXX-C-LINK %s +// CHECK-BASIC-LIBCXX-C-LINK-NOT: warning: +// CHECK-BASIC-LIBCXX-C-LINK: "{{[^"]*}}clang{{[^"]*}}" "-cc1" +// CHECK-BASIC-LIBCXX-C-LINK: "-isysroot" "[[SYSROOT:[^"]+]]" +// CHECK-BASIC-LIBCXX-C-LINK-NOT: "-internal-isystem" "[[SYSROOT]]/usr/bin/../include/c++/v1" +// CHECK-BASIC-LIBCXX-C-LINK: "-internal-isystem" "[[SYSROOT]]/usr/local/include" +// CHECK-BASIC-LIBCXX-C-LINK: "--sysroot=[[SYSROOT]]" +// CHECK-BASIC-LIBCXX-C-LINK: "-L[[SYSROOT]]/usr/bin/../lib" +// // Test a very broken version of multiarch that shipped in Ubuntu 11.04. // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \ // RUN: --target=i386-unknown-linux \