Fix Debug Build Using GCC 15 #152223
Fix Debug Build Using GCC 15 #152223
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@llvm/pr-subscribers-flang-fir-hlfir Author: Patrick Simmons (linuxrocks123) ChangesFlang currently doesn't build in debug mode on GCC 15 due to missing dynamic libraries in some CMakeLists.txt files, and OpenMP doesn't link in debug mode due to the atomic library pulling in libstdc++ despite an incomplete attempt in the CMakeLists.txt to disable glibcxx assertions. This PR fixes these issues and allows Flang and the OpenMP runtime to build and link on GCC 15 in debug mode. Full diff: https://github.com/llvm/llvm-project/pull/152223.diff 3 Files Affected:
diff --git a/flang/lib/Optimizer/Builder/CMakeLists.txt b/flang/lib/Optimizer/Builder/CMakeLists.txt
index 31ae395805faf..eb4413887e67e 100644
--- a/flang/lib/Optimizer/Builder/CMakeLists.txt
+++ b/flang/lib/Optimizer/Builder/CMakeLists.txt
@@ -49,6 +49,7 @@ add_flang_library(FIRBuilder
FIRDialectSupport
FIRSupport
FortranEvaluate
+ FortranSupport
HLFIRDialect
MLIR_DEPS
diff --git a/flang/lib/Optimizer/HLFIR/Transforms/CMakeLists.txt b/flang/lib/Optimizer/HLFIR/Transforms/CMakeLists.txt
index cc74273d9c5d9..3775a13e31e95 100644
--- a/flang/lib/Optimizer/HLFIR/Transforms/CMakeLists.txt
+++ b/flang/lib/Optimizer/HLFIR/Transforms/CMakeLists.txt
@@ -27,6 +27,8 @@ add_flang_library(HLFIRTransforms
FIRSupport
FIRTransforms
FlangOpenMPTransforms
+ FortranEvaluate
+ FortranSupport
HLFIRDialect
LINK_COMPONENTS
diff --git a/openmp/runtime/src/CMakeLists.txt b/openmp/runtime/src/CMakeLists.txt
index 569061c6494b8..9a2d490bdd65d 100644
--- a/openmp/runtime/src/CMakeLists.txt
+++ b/openmp/runtime/src/CMakeLists.txt
@@ -168,7 +168,7 @@ endif()
# Disable libstdc++ assertions, even in an LLVM_ENABLE_ASSERTIONS build, to
# avoid an unwanted dependency on libstdc++.so.
if(NOT WIN32)
- add_definitions(-U_GLIBCXX_ASSERTIONS)
+ add_definitions(-U_GLIBCXX_ASSERTIONS -D_GLIBCXX_NO_ASSERTIONS)
endif()
# Add the OpenMP library
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@LU-JOHN do you mind reviewing? |
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Flang changes look good to me. Thanks! |
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Looks good. |
…d std::exception symbols
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/10/builds/11941 Here is the relevant piece of the build log for the reference |
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Don't add this option by default as it will expose backend errors when building for the AMDGPU:
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| add_definitions(-U_GLIBCXX_ASSERTIONS -D_GLIBCXX_NO_ASSERTIONS) | ||
| add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-fno-exceptions>) | ||
| add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-O2>) |
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-U_GLIBCXX_ASSERTIONSand-fno-exceptionsare already added in AddFlangRT.cmake._GLIBCXX_NO_ASSERTIONSshould not be necessary, but could be an alternative to-U_GLIBCXX_ASSERTIONS- We prefer modern CMake style
- Adding
-O2overrides the choice ofCMAKE_BUILD_TYPE. What optimization level to use should be left to the user.
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Re 2: A suggested alternative syntax would be helpful in understanding what you are suggesting.
Re 3: I don't like forcing -O2 either, but I don't see an alternative to making the DCE happen that's necessary to get rid of the offending undefined symbol.
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target_compile_options and target_compile_definitions. See AddFlangRT.cmake. _GLIBCXX_ASSERTIONS and -fno-exceptions are already handled there. If there are any issus with those, it should be fixed in AddFlangRT.cmake, not here.
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@Meinersbur after checking again, I can verify that -fno-exceptions is present in compile_commands.json in the current master, so there's no need for a line adding it in this PR. -O2 must still be added, or else the build succeeds but the Fortran compiler cannot create executables because its runtime library has an undefined symbol.
In contrast to linking a static library, when linking a shared library all referenced symbols must be available in either the objects files, static libraries, or shared libraries passed to the linker command line and cannot be deferred to when building the executable. Fixes #150027 Same fix as included in #152223, but with only the changes necessary to fix #150027 (which is unrelated to GCC 15)
Since GCC 15.1, libstdc++ enabled assertions/hardening by default in non-optimized (-O0) builds [1]. That is, _GLIBCXX_ASSERTIONS is defined in the libstdc++ headers itself so defining/undefining it on the compiler command line no longer has an effect in non-optimized builds. As the commit message[2] suggests, define _GLIBCXX_NO_ASSERTIONS instead. For libstdc++ headers before 15.1, -U_GLIBCXX_ASSERTIONS still has to be on the command line as well. Defining _GLIBCXX_NO_ASSERTIONS was previously proposed in #152223 [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112808 [2] gcc-mirror/gcc@361d230
Flang currently doesn't build in debug mode on GCC 15 due to missing dynamic libraries in some CMakeLists.txt files, and OpenMP doesn't link in debug mode due to the atomic library pulling in libstdc++ despite an incomplete attempt in the CMakeLists.txt to disable glibcxx assertions. This PR fixes these issues and allows Flang and the OpenMP runtime to build and link on GCC 15 in debug mode.