Alexey Samsonov
2014-Mar-24 09:49 UTC
[LLVMdev] compiler-rt CMake build ignores CMAKE_CXX_FLAGS
Submitted r204593. On Sun, Mar 23, 2014 at 10:03 PM, Alexey Samsonov <samsonov at google.com>wrote:> Hi Dmitri, > > On Sat, Mar 22, 2014 at 11:50 PM, Dmitri Gribenko <gribozavr at gmail.com>wrote: > >> Hello, >> >> It looks like compiler-rt CMake scripts don't take CMAKE_CXX_FLAGS >> into account. This is because clang_compile and clang_link_shared >> functions call the newly-built compiler directly, and they don't add >> those flags. >> > > Indeed. > > >> >> Using CMAKE_CXX_FLAGS is necessary on systems where the C++11-enabled >> libstdc++ is installed not in the default location. For example, the >> CentOS buildbot uses: >> >> -DCMAKE_CXX_FLAGS=--gcc-toolchain=/opt/centos/devtoolset-1.1/root/usr >> >> I tried adding ${CMAKE_CXX_FLAGS} to the compiler invocation in >> clang_compile (with and without quotes), but in both cases the >> resulting command is not correct, all of CMAKE_CXX_FLAGS is treated as >> a single option, for example: >> > > Yes, recently I discovered the same problem and also though of adding > CMAKE_CXX_FLAGS > to manual clang invocations. I think it just needs to be done. > > >> >> [6/67] Generating gtest-all.cc.x86_64.o >> FAILED: cd >> /home/llvmbb/clang/build-cmake-r+a/projects/compiler-rt/lib/tsan/tests/unit >> && /home/llvmbb/clang/build-cmake-r+a/./bin/clang -fPIC -fno-builtin >> -fno-exceptions -fomit-frame-pointer -funwind-tables >> -fno-stack-protector -fvisibility=hidden -fno-function-sections -O3 >> -gline-tables-only -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions >> -Wno-non-virtual-dtor -fPIE -fno-rtti -DGTEST_NO_LLVM_RAW_OSTREAM=1 >> -I/home/llvmbb/clang/llvm/utils/unittest/googletest/include >> -I/home/llvmbb/clang/llvm/utils/unittest/googletest >> -I/home/llvmbb/clang/llvm/projects/compiler-rt/lib >> -I/home/llvmbb/clang/llvm/projects/compiler-rt/lib/tsan/rtl -std=c++11 >> -DGTEST_HAS_RTTI=0 >> --gcc-toolchain=/opt/centos/devtoolset-1.1/root/usr\ -fPIC\ >> -fvisibility-inlines-hidden\ -Wall\ -W\ -Wno-unused-parameter\ >> -Wwrite-strings\ -Wmissing-field-initializers\ -pedantic\ >> -Wno-long-long\ -Wcovered-switch-default\ -Wnon-virtual-dtor\ >> -std=c++11\ -fcolor-diagnostics\ -ffunction-sections\ -fdata-sections\ >> -Wall\ -std=c++11 -m64 -c -o gtest-all.cc.x86_64.o >> /home/llvmbb/clang/llvm/utils/unittest/googletest/src/gtest-all.cc >> >> Note the backslases in the command. >> > > Yep, because CMAKE_CXX_FLAGS is a string, and its contents is automatically > escaped when we use it in COMMAND in CMake rules. I guess we'll have to > manually > turn CMAKE_CXX_FLAGS into a CMake semicolon-separated list. > > >> >> Could maintainers of the compiler-rt CMake scripts help me with this? >> > > Thanks for the detailed description of your use case. > I will try to address this problem tomorrow. > > >> >> Dmitri >> >> -- >> main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if >> (j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/ >> > > -- > Alexey Samsonov, MSK >-- Alexey Samsonov, MSK -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140324/ff340457/attachment.html>
Dmitri Gribenko
2014-Mar-24 10:09 UTC
[LLVMdev] compiler-rt CMake build ignores CMAKE_CXX_FLAGS
On Mon, Mar 24, 2014 at 9:49 AM, Alexey Samsonov <samsonov at google.com> wrote:> Submitted r204593.Thank you! It did fix compiling the tests on the buildbot, but I am surprised that linking succeeded. Maybe that is because we are not using any C++11 features that require symbols from the newer libstdc++. But it would be future-proof to change clang_link_shared() to use CMAKE_CXX_FLAGS as well. Dmitri -- main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if (j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/
Alexey Samsonov
2014-Mar-24 13:26 UTC
[LLVMdev] compiler-rt CMake build ignores CMAKE_CXX_FLAGS
On Mon, Mar 24, 2014 at 2:09 PM, Dmitri Gribenko <gribozavr at gmail.com>wrote:> On Mon, Mar 24, 2014 at 9:49 AM, Alexey Samsonov <samsonov at google.com> > wrote: > > Submitted r204593. > > Thank you! It did fix compiling the tests on the buildbot, but I am > surprised that linking succeeded. Maybe that is because we are not > using any C++11 features that require symbols from the newer > libstdc++. But it would be future-proof to change clang_link_shared() > to use CMAKE_CXX_FLAGS as well. >Is there really a logic in Clang that would choose between old and newer libstdc++ versions depending on the value of -std= flag? I hope to get rid of clang_compile and clang_link_shared horridness soon by switching to LLVM_BUILD_EXTERNAL_COMPILER_RT=ON that would use just-built Clang to configure/build compiler-rt. So, your use case might be interesting. Can you build with -DLLVM_BUILD_EXTERNAL_COMPILER_RT=ON and check if "make check-compiler-rt" works for you? If not, then we'd have to propagate *some* CMAKE_CXX_FLAGS to configuration step of compiler-rt project, but we won't need most of the extra flags stuffed into CMAKE_CXX_FLAGS by LLVM/Clang CMake files. It might be a problem (sigh).> > Dmitri > > -- > main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if > (j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/ >-- Alexey Samsonov, MSK -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140324/7be258aa/attachment.html>