From 528517aa742e812a754b5e85993bfaa490537880 Mon Sep 17 00:00:00 2001 From: Hubert Tong Date: Fri, 23 Oct 2020 14:25:22 -0400 Subject: [PATCH] [AIX][cmake] Adjust management of `-G` for linking The change in 0ba98433971f changed the behaviour of the build when using an XL build compiler because `-G` is not a pure linker option: it also implies `-shared`. This was accounted for in the base CMake configuration, so an analysis of the change from 0ba98433971f in relation to a build using Clang (where `-shared` is introduced by CMake) would not identify the issue. This patch resolves this particular issue by adding `-shared` alongside `-Wl,-G`. At the same time, the investigation reveals that several aspects of the various build configurations are not operating in the manner originally intended. The other issue related to the `-G` linker option in the build is that the removal of it (to avoid unnecessary use of run-time linking) is not effective for the build using the Clang compiler. This patch addresses this by adjusting the regular expressions used to remove the broadly- applied `-G`. Finally, the issue of specifying the export list with `-Wl,` instead of a compiler option is flagged with a FIXME comment. Reviewed By: daltenty, amyk Differential Revision: https://reviews.llvm.org/D90041 --- CMakeLists.txt | 24 +++++++++++++++--------- cmake/modules/AddLLVM.cmake | 2 ++ 2 files changed, 17 insertions(+), 9 deletions(-) diff --git a/CMakeLists.txt b/CMakeLists.txt index 39d78c70c02..ebc6733b587 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -917,20 +917,26 @@ if (UNIX AND ${CMAKE_SYSTEM_NAME} MATCHES "AIX") # configuration, it is still possible the user may force it as part of a # compound option. if(CMAKE_VERSION VERSION_LESS 3.16) - string(REGEX REPLACE "(^|[ \t]+)-Wl,-brtl([ \t]+|$)" "" CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}") - string(REGEX REPLACE "(^|[ \t]+)-Wl,-brtl([ \t]+|$)" "" CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}") - string(REGEX REPLACE "(^|[ \t]+)-Wl,-brtl([ \t]+|$)" "" CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS}") - string(REGEX REPLACE "(^|[ \t]+)(-Wl,)?-G([ \t]+|$)" "" CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS + string(REGEX REPLACE "(^|[ \t]+)-Wl,-brtl([ \t]+|$)" " " CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}") + string(REGEX REPLACE "(^|[ \t]+)-Wl,-brtl([ \t]+|$)" " " CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}") + string(REGEX REPLACE "(^|[ \t]+)-Wl,-brtl([ \t]+|$)" " " CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS}") + string(REGEX REPLACE "(^|[ \t]+)(-Wl,)?-G([ \t]+|$)" " " CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS "${CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS}") - string(REGEX REPLACE "(^|[ \t]+)(-Wl,)?-G([ \t]+|$)" "" CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS + string(REGEX REPLACE "(^|[ \t]+)(-Wl,)?-G([ \t]+|$)" " " CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS "${CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS}") - string(REGEX REPLACE "(^|[ \t]+)(-Wl,)?-G([ \t]+|$)" "" CMAKE_SHARED_LIBRARY_CREATE_ASM_FLAGS + string(REGEX REPLACE "(^|[ \t]+)(-Wl,)?-G([ \t]+|$)" " " CMAKE_SHARED_LIBRARY_CREATE_ASM_FLAGS + "${CMAKE_SHARED_LIBRARY_CREATE_ASM_FLAGS}") + string(REGEX REPLACE "(^|[ \t]+)-Wl,-G," " -Wl," CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS + "${CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS}") + string(REGEX REPLACE "(^|[ \t]+)-Wl,-G," " -Wl," CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS + "${CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS}") + string(REGEX REPLACE "(^|[ \t]+)-Wl,-G," " -Wl," CMAKE_SHARED_LIBRARY_CREATE_ASM_FLAGS "${CMAKE_SHARED_LIBRARY_CREATE_ASM_FLAGS}") endif() - # Modules should be built with -G, so we can use runtime linking with - # plugins. - string(APPEND CMAKE_MODULE_LINKER_FLAGS " -Wl,-G") + # Modules should be built with -shared -Wl,-G, so we can use runtime linking + # with plugins. + string(APPEND CMAKE_MODULE_LINKER_FLAGS " -shared -Wl,-G") # Also set the correct flags for building shared libraries. string(APPEND CMAKE_SHARED_LINKER_FLAGS " -shared") diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake index 28ab010bb8e..4f11d2f2bda 100644 --- a/cmake/modules/AddLLVM.cmake +++ b/cmake/modules/AddLLVM.cmake @@ -90,6 +90,8 @@ function(add_llvm_symbol_exports target_name export_file) set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS " -Wl,-exported_symbols_list,\"${CMAKE_CURRENT_BINARY_DIR}/${native_export_file}\"") elseif(${CMAKE_SYSTEM_NAME} MATCHES "AIX") + # FIXME: `-Wl,-bE:` bypasses whatever handling there is in the build + # compiler driver to defer to the specified export list. set(native_export_file "${export_file}") set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS " -Wl,-bE:${export_file}")