Author: Hubert Tong
Date: 2020-10-23T14:32:36-04:00
New Revision: 1602c6fd9294494aaa7461e258602d486166b303
URL: https://github.com/llvm/llvm-project/commit/1602c6fd9294494aaa7461e258602d486166b303
DIFF: https://github.com/llvm/llvm-project/commit/1602c6fd9294494aaa7461e258602d486166b303.diff
LOG: [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
Added:
Modified:
llvm/CMakeLists.txt
llvm/cmake/modules/AddLLVM.cmake
Removed:
################################################################################
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 39d78c70c02e..ebc6733b5873 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/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/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
index 28ab010bb8ef..4f11d2f2bda4 100644
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/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}")