From 537d964fab8b3f524eb3622c53f22279ea14fd62 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. Fixes: #23123 Signed-off-by: Björn Esser --- Modules/FortranCInterface/CMakeLists.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Modules/FortranCInterface/CMakeLists.txt b/Modules/FortranCInterface/CMakeLists.txt index 13e4498ad9..f21b92fc54 100644 --- a/Modules/FortranCInterface/CMakeLists.txt +++ b/Modules/FortranCInterface/CMakeLists.txt @@ -5,6 +5,15 @@ cmake_minimum_required(VERSION ${CMAKE_VERSION}) project(FortranCInterface C Fortran) include(${FortranCInterface_BINARY_DIR}/Input.cmake OPTIONAL) +# 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. +if(CMAKE_Fortran_COMPILER_ID STREQUAL "GNU" AND + CMAKE_Fortran_COMPILER_VERSION VERSION_GREATER_EQUAL 12) + string(APPEND CMAKE_C_FLAGS " -fno-lto") + string(APPEND CMAKE_Fortran_FLAGS " -fno-lto") +endif() + # Check if the C compiler supports '$' in identifiers. include(CheckCSourceCompiles) check_c_source_compiles(" -- 2.34.1