linker: ld: toolchain_linker_finalize duplicates <LINKER_FLAGS> leading to link issues in some situations #82281
Description
Describe the bug
toolchain_linker_finalize was introduced by PR #78320 and according to its implementation for LD, it duplicates <LINKER_FLAGS>.
This is not a huge problem for common flags, but we got an issue when using --whole-archive xxx --no-whole-archive.
When this flag is duplicated, the linker exits with a duplicate definition error.
We've faced this issue in the connectedhomeip environment when migrating to 4.0 release.
cc @tejlmand
To Reproduce
Use the following cmake instruction:
target_link_options(${target} INTERFACE -Wl,--whole-archive <some static lib> -Wl,--no-whole-archive
This flag will be duplicated in the link command, leading to duplicate definitions.
Expected behavior
Link flags added with target_link_options should be unique.
Impact
We can currently workaround by bypassing the target_link_options and manually link the symbols we want, but this is not acceptable in the long run.
Logs and console output
I printed the content of CMAKE_CXX_LINK_EXECUTABLE before and after toolchain_link_options is called:
-- CMAKE_CXX_LINK_EXECUTABLE: <CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>
-- CMAKE_CXX_LINK_EXECUTABLE: <CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES> -L"/opt/zephyr-sdk-0.16.8/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/thumb/v8-m.main+fp/hard" -lstdc++ -lm -lc -lgcc -lc
We can see <LINK_FLAGS> is duplicated by the function
Environment (please complete the following information):
- OS: Linux
- Toolchain: Zephyr SDK
- Commit SHA or Version used:
2e3873adde2386e0bc9acdbcdc8d389fdf4b9aee
Additional context
Proposed patch:
diff --git a/cmake/linker/ld/target.cmake b/cmake/linker/ld/target.cmake
index 5e0a117c014..f9cdc938f54 100644
--- a/cmake/linker/ld/target.cmake
+++ b/cmake/linker/ld/target.cmake
@@ -148,7 +148,7 @@ macro(toolchain_linker_finalize)
string(REPLACE ";" " " zephyr_std_libs "${zephyr_std_libs}")
set(link_libraries "<LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${zephyr_std_libs}")
- set(common_link "<LINK_FLAGS> ${link_libraries}")
+ set(common_link "${link_libraries}")
set(CMAKE_ASM_LINK_EXECUTABLE "<CMAKE_ASM_COMPILER> <FLAGS> <CMAKE_ASM_LINK_FLAGS> ${common_link}")
set(CMAKE_C_LINK_EXECUTABLE "<CMAKE_C_COMPILER> <FLAGS> <CMAKE_C_LINK_FLAGS> ${common_link}")