qt5base-lts/cmake/QtSeparateDebugInfo.cmake
Alexandru Croitor 39f657032b CMake: Generate and use a wrapper script for stripping binaries
MinGW 11.2.0 comes with a strip.exe that strips the ".gnu_debuglink"
section in binaries, a section that is needed for the separate debug
information feature.

binutils version 2.34 mentions the feature for the first time:
https://sourceware.org/binutils/docs-2.34/binutils/strip.html#strip

To ensure the debuglink section is preserved, generate a shell wrapper
that calls the original strip binary with an extra option to keep the
required section.

To determine if the option is supported, we build a real shared library
on which strip will be called with the --keep-section option.
If the option is not supported, a wrapper is not generated and the
stock strip binary is used.

This logic only applies when targeting Linux and MinGW + a shared
library Qt. For other targets, the stock strip binary is used.

Developers can opt out of this logic by passing
-DQT_NO_STRIP_WRAPPER=TRUE when configuring each Qt repo.

Pick-to: 6.2 6.3
Fixes: QTBUG-101653
Change-Id: Idd213d48d087d3c9600c853362aebaba348cde33
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
2022-03-24 21:50:50 +01:00

280 lines
11 KiB
CMake

include(CMakeFindBinUtils)
if(CMAKE_VERSION VERSION_LESS 3.17.0)
set(CMAKE_CURRENT_FUNCTION_LIST_DIR ${CMAKE_CURRENT_LIST_DIR})
endif()
# Builds a shared library which will have strip run on it.
function(qt_internal_try_compile_binary_for_strip binary_out_var)
# Need to find the config.tests files depending on which repo we are building.
if(EXISTS "${QT_CMAKE_DIR}")
# building qtbase
set(basedir "${QT_CMAKE_DIR}/..")
else()
# building other repo
set(basedir "${_qt_cmake_dir}/${QT_CMAKE_EXPORT_NAMESPACE}")
endif()
set(config_test_dir "config.tests/binary_for_strip")
set(src_dir "${basedir}/${config_test_dir}")
# Make sure the built project files are not installed when doing an in-source build (like it
# happens in Qt's CI) by choosing a build dir that does not coincide with the installed
# source dir.
set(binary_dir "${CMAKE_CURRENT_BINARY_DIR}/${config_test_dir}_built")
set(flags "")
qt_get_platform_try_compile_vars(platform_try_compile_vars)
list(APPEND flags ${platform_try_compile_vars})
# CI passes the project dir of the Qt repository as absolute path without drive letter:
# \Users\qt\work\qt\qtbase
# Ensure that arg_PROJECT_PATH is an absolute path with drive letter:
# C:/Users/qt/work/qt/qtbase
# This works around CMake upstream issue #22534.
if(CMAKE_HOST_WIN32)
get_filename_component(src_dir "${src_dir}" REALPATH)
endif()
# Build a real binary that strip can be run on.
try_compile(QT_INTERNAL_BUILT_BINARY_FOR_STRIP
"${binary_dir}"
"${src_dir}"
binary_for_strip # project name
OUTPUT_VARIABLE build_output
CMAKE_FLAGS ${flags}
)
# Retrieve the binary path from the build output.
string(REGEX REPLACE ".+###(.+)###.+" "\\1" output_binary_path "${build_output}")
if(NOT EXISTS "${output_binary_path}")
message(FATAL_ERROR "Extracted binary path for strip does not exist: ${output_binary_path}")
endif()
set(${binary_out_var} "${output_binary_path}" PARENT_SCOPE)
endfunction()
# When using the MinGW 11.2.0 toolchain, cmake --install --strip as used by
# qt-cmake-private-intstall.cmake, removes the .gnu_debuglink section in binaries and thus
# breaks the separate debug info feature.
#
# Generate a wrapper shell script that passes an option to keep the debug section.
# The wrapper is used when targeting Linux or MinGW with a shared Qt build.
# The check to see if the option is supported by 'strip', is done once for every repo configured,
# because different machines might have different strip versions installed, without support for
# the option we need.
#
# Once CMake supports custom strip arguments, we can remove the part that creates a shell wrapper.
# https://gitlab.kitware.com/cmake/cmake/-/issues/23346
function(qt_internal_generate_binary_strip_wrapper)
# Return early if check was done already, if explicitly skipped, or when building a static Qt.
if(DEFINED CACHE{QT_INTERNAL_STRIP_SUPPORTS_KEEP_SECTION}
OR QT_NO_STRIP_WRAPPER
OR (NOT QT_BUILD_SHARED_LIBS)
)
return()
endif()
# To make reconfiguration more robust when QT_INTERNAL_STRIP_SUPPORTS_KEEP_SECTION is manually
# removed, make sure to always find the original strip first, by first removing the cached var
# and then finding the binary again.
unset(CMAKE_STRIP CACHE)
include(CMakeFindBinUtils)
# Target Linux and MinGW.
if((UNIX OR MINGW)
AND NOT APPLE
AND CMAKE_STRIP)
# Getting path to a binary we can run strip on.
qt_internal_try_compile_binary_for_strip(valid_binary_path)
# The strip arguments are used both for the execute_process test and also as content
# in the file created by configure_file.
set(strip_arguments "--keep-section=.gnu_debuglink")
# Check if the option is supported.
message(STATUS "Performing Test strip --keep-section")
execute_process(
COMMAND
"${CMAKE_STRIP}" ${strip_arguments} "${valid_binary_path}"
OUTPUT_VARIABLE strip_probe_output
ERROR_VARIABLE strip_probe_output
RESULT_VARIABLE strip_result_var
)
# A successful strip of a binary should have a '0' exit code.
if(NOT strip_result_var STREQUAL "0")
set(keep_section_supported FALSE)
else()
set(keep_section_supported TRUE)
endif()
# Cache the result.
set(QT_INTERNAL_STRIP_SUPPORTS_KEEP_SECTION "${keep_section_supported}" CACHE BOOL
"strip supports --keep-section")
message(DEBUG
"qt_internal_generate_binary_strip_wrapper:\n"
"original strip: ${CMAKE_STRIP}\n"
"strip probe output: ${strip_probe_output}\n"
"strip result: ${strip_result_var}\n"
"keep section supported: ${keep_section_supported}\n"
)
message(STATUS "Performing Test strip --keep-section - ${keep_section_supported}")
# If the option is not supported, don't generate a wrapper and just use the stock binary.
if(NOT keep_section_supported)
return()
endif()
set(wrapper_extension "")
if(NOT CMAKE_HOST_UNIX)
set(wrapper_extension ".bat")
endif()
set(script_name "qt-internal-strip")
if(EXISTS "${QT_CMAKE_DIR}")
# qtbase build-tree case
set(wrapper_in_basedir "${QT_CMAKE_DIR}/..")
else()
# other repo case
set(wrapper_in_basedir "${_qt_cmake_dir}/${QT_CMAKE_EXPORT_NAMESPACE}")
endif()
# the libexec literal is used on purpose for the source, so the file is found
# on Windows hosts.
set(wrapper_in
"${wrapper_in_basedir}/libexec/${script_name}${wrapper_extension}.in")
set(wrapper_out "${QT_BUILD_DIR}/${INSTALL_LIBEXECDIR}/${script_name}${wrapper_extension}")
set(original_strip "${CMAKE_STRIP}")
configure_file("${wrapper_in}" "${wrapper_out}" @ONLY)
# Backup the original strip path for informational purposes.
set(QT_INTERNAL_ORIGINAL_STRIP "${original_strip}" CACHE INTERNAL "Original strip binary")
# Override the strip binary to be used by CMake install target.
set(CMAKE_STRIP "${wrapper_out}" CACHE INTERNAL "Custom Qt strip wrapper")
endif()
endfunction()
# Enable separate debug information for the given target
function(qt_enable_separate_debug_info target installDestination)
set(flags QT_EXECUTABLE)
set(options)
set(multiopts ADDITIONAL_INSTALL_ARGS)
cmake_parse_arguments(arg "${flags}" "${options}" "${multiopts}" ${ARGN})
if (NOT QT_FEATURE_separate_debug_info)
return()
endif()
if (NOT UNIX AND NOT MINGW)
return()
endif()
get_target_property(target_type ${target} TYPE)
if (NOT target_type STREQUAL "MODULE_LIBRARY" AND
NOT target_type STREQUAL "SHARED_LIBRARY" AND
NOT target_type STREQUAL "EXECUTABLE")
return()
endif()
get_property(target_source_dir TARGET ${target} PROPERTY SOURCE_DIR)
get_property(skip_separate_debug_info DIRECTORY "${target_source_dir}" PROPERTY _qt_skip_separate_debug_info)
if (skip_separate_debug_info)
return()
endif()
unset(commands)
if(APPLE)
find_program(DSYMUTIL_PROGRAM dsymutil)
set(copy_bin ${DSYMUTIL_PROGRAM})
set(strip_bin ${CMAKE_STRIP})
set(debug_info_suffix dSYM)
set(copy_bin_out_arg --flat -o)
set(strip_args -S)
else()
set(copy_bin ${CMAKE_OBJCOPY})
set(strip_bin ${CMAKE_OBJCOPY})
if(QNX)
set(debug_info_suffix sym)
set(debug_info_keep --keep-file-symbols)
set(strip_args "--strip-debug -R.ident")
else()
set(debug_info_suffix debug)
set(debug_info_keep --only-keep-debug)
set(strip_args --strip-debug)
endif()
endif()
if(APPLE)
get_target_property(is_framework ${target} FRAMEWORK)
if(is_framework)
qt_internal_get_framework_info(fw ${target})
set(debug_info_bundle_dir "$<TARGET_BUNDLE_DIR:${target}>.${debug_info_suffix}")
set(BUNDLE_ID ${fw_name})
else()
set(debug_info_bundle_dir "$<TARGET_FILE:${target}>.${debug_info_suffix}")
set(BUNDLE_ID ${target})
endif()
set(debug_info_contents_dir "${debug_info_bundle_dir}/Contents")
set(debug_info_target_dir "${debug_info_contents_dir}/Resources/DWARF")
configure_file(
"${CMAKE_CURRENT_FUNCTION_LIST_DIR}/QtSeparateDebugInfo.Info.plist.in"
"Info.dSYM.plist"
)
list(APPEND commands
COMMAND ${CMAKE_COMMAND} -E make_directory ${debug_info_target_dir}
COMMAND ${CMAKE_COMMAND} -E copy "Info.dSYM.plist" "${debug_info_contents_dir}/Info.plist"
)
set(debug_info_target "${debug_info_target_dir}/$<TARGET_FILE_BASE_NAME:${target}>")
if(arg_QT_EXECUTABLE AND QT_FEATURE_debug_and_release)
qt_get_cmake_configurations(cmake_configs)
foreach(cmake_config ${cmake_configs})
# Make installation optional for targets that are not built by default in this config
if(NOT (cmake_config STREQUAL QT_MULTI_CONFIG_FIRST_CONFIG))
set(install_optional_arg OPTIONAL)
else()
unset(install_optional_arg)
endif()
qt_install(DIRECTORY ${debug_info_bundle_dir}
${arg_ADDITIONAL_INSTALL_ARGS}
${install_optional_arg}
CONFIGURATIONS ${cmake_config}
DESTINATION ${installDestination})
endforeach()
else()
qt_install(DIRECTORY ${debug_info_bundle_dir}
${arg_ADDITIONAL_INSTALL_ARGS}
DESTINATION ${installDestination})
endif()
else()
set(debug_info_target "$<TARGET_FILE_DIR:${target}>/$<TARGET_FILE_BASE_NAME:${target}>.${debug_info_suffix}")
qt_install(FILES ${debug_info_target} DESTINATION ${installDestination})
endif()
list(APPEND commands
COMMAND ${copy_bin} ${debug_info_keep} $<TARGET_FILE:${target}>
${copy_bin_out_arg} ${debug_info_target}
COMMAND ${strip_bin} ${strip_args} $<TARGET_FILE:${target}>
)
if(NOT APPLE)
list(APPEND commands
COMMAND ${CMAKE_OBJCOPY} --add-gnu-debuglink=${debug_info_target} $<TARGET_FILE:${target}>
)
endif()
if(NOT CMAKE_HOST_WIN32)
list(APPEND commands
COMMAND chmod -x ${debug_info_target}
)
endif()
add_custom_command(
TARGET ${target}
POST_BUILD
${commands}
VERBATIM)
endfunction()