From 6a0ce19ce1cb594cdec19bacc9fc7a38156e38da Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Esser?= Date: Wed, 19 Jan 2022 17:26:14 +0100 Subject: [PATCH] FortranCInterface: Fix compatibility with GCC gfortran 12 LTO MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since version 12.0 the GCC Fortran compiler has implemented "WG5/N1942", which causes, if link-time opmization is enabled, obfuscation of hard-coded string values in the compiler objects and its resulting ELF-binaries. This causes the CMake-internal detection of the mangling scheme for the naming of subroutines to fail. Thus we must ensure to have any link-time optimization features to be disabled on the executable file we perform the detection on. The static libraries, however, must be build with LTO and non-LTO objects, as that will ensure the verify step will operate on IPO objects, if building those is requested by the system compiler flags. Fixes: #23123 Signed-off-by: Björn Esser --- Modules/FortranCInterface/CMakeLists.txt | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/Modules/FortranCInterface/CMakeLists.txt b/Modules/FortranCInterface/CMakeLists.txt index 13e4498ad9..ce0bc10c8e 100644 --- a/Modules/FortranCInterface/CMakeLists.txt +++ b/Modules/FortranCInterface/CMakeLists.txt @@ -102,6 +102,19 @@ set_property(TARGET symbols PROPERTY POSITION_INDEPENDENT_CODE 1) add_executable(FortranCInterface main.F call_sub.f ${call_mod}) target_link_libraries(FortranCInterface PUBLIC symbols) +# If IPO is enabled here, GCC gfortran >= 12.0 will obfuscate +# the strings of the return values in the compiled executable, +# which we use to regex match against later. +# The static libraries must be build with IPO and non-IPO objects, +# as that will ensure the verify step will operate on IPO objects, +# if requested by the system compiler flags. +if(CMAKE_Fortran_COMPILER_ID STREQUAL "GNU" AND + CMAKE_Fortran_COMPILER_VERSION VERSION_GREATER_EQUAL 12) + target_compile_options(FortranCInterface PRIVATE "-fno-lto") + target_compile_options(myfort PRIVATE "-flto=auto" "-ffat-lto-objects") + target_compile_options(symbols PRIVATE "-flto=auto" "-ffat-lto-objects") +endif() + file(GENERATE OUTPUT exe-$.cmake CONTENT [[ set(FortranCInterface_EXE "$") ]]) -- 2.34.1