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Fix Debug Build Using GCC 15 #152223

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Merged
merged 6 commits into from
Aug 21, 2025
Merged

Fix Debug Build Using GCC 15 #152223

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c765573
Fix build on GCC 15
linuxrocks123 Aug 5, 2025
72b5c63
Additional glibc assert flag
linuxrocks123 Aug 7, 2025
d5e848b
-O2 must be used even in debug mode so that DCE will get rid of unuse…
linuxrocks123 Aug 7, 2025
79ee0e4
Fix syntax
linuxrocks123 Aug 7, 2025
1c65f6a
Merge branch 'main' into 20250805
ronlieb Aug 21, 2025
875c25e
Merge branch 'main' into 20250805
ronlieb Aug 21, 2025
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4 changes: 4 additions & 0 deletions flang-rt/lib/runtime/CMakeLists.txt
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Expand Up @@ -183,6 +183,10 @@ endif ()


if (NOT WIN32)
add_definitions(-U_GLIBCXX_ASSERTIONS -D_GLIBCXX_NO_ASSERTIONS)
add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-fno-exceptions>)
add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-O2>)
Comment on lines +186 to +188
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@Meinersbur Meinersbur Aug 22, 2025 •
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  1. -U_GLIBCXX_ASSERTIONS and -fno-exceptions are already added in AddFlangRT.cmake. _GLIBCXX_NO_ASSERTIONS should not be necessary, but could be an alternative to -U_GLIBCXX_ASSERTIONS
  2. We prefer modern CMake style
  3. Adding -O2 overrides the choice of CMAKE_BUILD_TYPE. What optimization level to use should be left to the user.

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@linuxrocks123 linuxrocks123 Aug 26, 2025

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@Meinersbur

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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@Meinersbur Meinersbur Aug 26, 2025

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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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@linuxrocks123 linuxrocks123 Aug 28, 2025 •
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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.


add_flangrt_library(flang_rt.runtime STATIC SHARED
${sources}
LINK_LIBRARIES ${Backtrace_LIBRARY}
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1 change: 1 addition & 0 deletions flang/lib/Optimizer/Builder/CMakeLists.txt
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Expand Up @@ -50,6 +50,7 @@ add_flang_library(FIRBuilder
FIRDialectSupport
FIRSupport
FortranEvaluate
FortranSupport
HLFIRDialect

MLIR_DEPS
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2 changes: 2 additions & 0 deletions flang/lib/Optimizer/HLFIR/Transforms/CMakeLists.txt
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Expand Up @@ -27,6 +27,8 @@ add_flang_library(HLFIRTransforms
FIRSupport
FIRTransforms
FlangOpenMPTransforms
FortranEvaluate
FortranSupport
HLFIRDialect

LINK_COMPONENTS
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2 changes: 1 addition & 1 deletion openmp/runtime/src/CMakeLists.txt
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Expand Up @@ -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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