build_tools/third_party/libbacktrace/CMakeLists.txt - 3p/openxla/iree - Git at Google

 # Copyright 2025 The IREE Authors
 #
 # Licensed under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

 # Build libbacktrace from source for Linux stack traces.
 # Uses FetchContent to pull upstream and provides our own CMake build.
 #
 # libbacktrace (https://github.com/ianlancetaylor/libbacktrace) provides
 # complete stack trace functionality including unwinding and symbol resolution
 # with file:line:function information.

 # Only build libbacktrace on Linux when enabled.
 # Other platforms have their own stack trace implementations:
 # - Windows: dbghelp
 # - macOS: backtrace+dladdr
 if(NOT CMAKE_SYSTEM_NAME STREQUAL "Linux" OR NOT IREE_ENABLE_LIBBACKTRACE)
   # Set empty target variable for consumers to use in DEPS.
   set(IREE_LIBBACKTRACE_TARGET "" CACHE INTERNAL "libbacktrace target (empty when disabled)")
   return()
 endif()

 # Set target variable for consumers to use in DEPS.
 set(IREE_LIBBACKTRACE_TARGET "libbacktrace::libbacktrace" CACHE INTERNAL "libbacktrace target")

 include(CheckSymbolExists)
 include(FetchContent)

 # pthreads is required for pthread_once used in status_stack_trace.c.
 find_package(Threads REQUIRED)

 # Suppress deprecation warning for FetchContent_Populate (CMake 4.x).
 # We use Populate because libbacktrace has no CMakeLists.txt.
 if(POLICY CMP0169)
   cmake_policy(SET CMP0169 OLD)
 endif()

 # Pin to a specific commit for reproducibility.
 set(LIBBACKTRACE_VERSION "b9e40069c0b47a722286b94eb5231f7f05c08713")

 FetchContent_Declare(
   libbacktrace_src
   GIT_REPOSITORY https://github.com/ianlancetaylor/libbacktrace.git
   GIT_TAG        ${LIBBACKTRACE_VERSION}
   EXCLUDE_FROM_ALL
 )

 # Just populate, don't configure (upstream has no CMake).
 FetchContent_GetProperties(libbacktrace_src)
 if(NOT libbacktrace_src_POPULATED)
   FetchContent_Populate(libbacktrace_src)
 endif()
 set(LIBBACKTRACE_SOURCE_DIR "${libbacktrace_src_SOURCE_DIR}")

 # Detect dl_iterate_phdr availability at configure time.
 # This is critical for cross-compilation: the check uses the cross-toolchain
 # so it correctly detects target capabilities, not host.
 # - glibc: always has it
 # - musl: has it (with some quirks on older versions)
 # - uclibc-ng: depends on configuration
 # - newlib/other minimal libc: usually not
 set(CMAKE_REQUIRED_DEFINITIONS -D_GNU_SOURCE)
 check_symbol_exists(dl_iterate_phdr "link.h" LIBBACKTRACE_HAVE_DL_ITERATE_PHDR)
 unset(CMAKE_REQUIRED_DEFINITIONS)

 if(LIBBACKTRACE_HAVE_DL_ITERATE_PHDR)
   set(LIBBACKTRACE_DL_ITERATE_PHDR_DEF "#define HAVE_DL_ITERATE_PHDR 1")
   set(LIBBACKTRACE_LINK_H_DEF "#define HAVE_LINK_H 1")
 else()
   message(STATUS "libbacktrace: dl_iterate_phdr not found, shared library symbols won't be resolved")
   set(LIBBACKTRACE_DL_ITERATE_PHDR_DEF "/* dl_iterate_phdr not available */")
   set(LIBBACKTRACE_LINK_H_DEF "/* link.h not available */")
 endif()

 # Generate config.h with detected features.
 # Uses @VAR@ substitution for cross-compilation-safe detection.
 configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/config.h.in
   ${LIBBACKTRACE_SOURCE_DIR}/config.h
   @ONLY
 )
 configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/backtrace-supported.h
   ${LIBBACKTRACE_SOURCE_DIR}/backtrace-supported.h
   COPYONLY
 )
 # Copy our wrapper header that re-exports backtrace.h.
 # This provides a consistent include path for both CMake and Bazel builds,
 # allowing status_stack_trace.c to use <iree_libbacktrace.h>.
 configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/iree_libbacktrace.h
   ${LIBBACKTRACE_SOURCE_DIR}/iree_libbacktrace.h
   COPYONLY
 )

 # Source files - include all platforms, let preprocessor handle selection.
 # Order matters for archive linking: implementations must come before stubs.
 # The linker picks the first symbol definition it finds when resolving from
 # an archive, so we list real implementations first and fallback stubs last.
 set(LIBBACKTRACE_SOURCES
   # Core files (always needed).
   ${LIBBACKTRACE_SOURCE_DIR}/atomic.c
   ${LIBBACKTRACE_SOURCE_DIR}/dwarf.c
   ${LIBBACKTRACE_SOURCE_DIR}/fileline.c
   ${LIBBACKTRACE_SOURCE_DIR}/posix.c
   ${LIBBACKTRACE_SOURCE_DIR}/print.c
   ${LIBBACKTRACE_SOURCE_DIR}/sort.c
   ${LIBBACKTRACE_SOURCE_DIR}/state.c
   # Unwinding - real implementations before stub.
   ${LIBBACKTRACE_SOURCE_DIR}/backtrace.c
   ${LIBBACKTRACE_SOURCE_DIR}/simple.c
   ${LIBBACKTRACE_SOURCE_DIR}/nounwind.c  # Stub, must be after backtrace.c/simple.c.
   # Executable format - ELF/Mach-O/PE before unknown stub.
   ${LIBBACKTRACE_SOURCE_DIR}/elf.c
   ${LIBBACKTRACE_SOURCE_DIR}/macho.c
   ${LIBBACKTRACE_SOURCE_DIR}/pecoff.c
   ${LIBBACKTRACE_SOURCE_DIR}/unknown.c  # Stub, must be after format files.
   # File I/O - mmap before read fallback.
   ${LIBBACKTRACE_SOURCE_DIR}/mmap.c
   ${LIBBACKTRACE_SOURCE_DIR}/mmapio.c
   ${LIBBACKTRACE_SOURCE_DIR}/read.c  # Fallback, must be after mmapio.c.
 )

 # Build libbacktrace as a STATIC library.
 # libbacktrace has multiple implementations of the same functions for different
 # platforms (e.g., elf.c vs pecoff.c vs macho.c). The autotools build selects
 # files at configure time, but we include all files and rely on archive linking
 # semantics - the linker only pulls in object files needed to resolve symbols,
 # so the first implementation wins and duplicates are ignored.
 add_library(libbacktrace_impl STATIC ${LIBBACKTRACE_SOURCES})
 target_include_directories(libbacktrace_impl
   PUBLIC $<BUILD_INTERFACE:${LIBBACKTRACE_SOURCE_DIR}>
 )
 target_compile_definitions(libbacktrace_impl
   PRIVATE _GNU_SOURCE  # Required for dl_iterate_phdr on glibc.
 )
 # Suppress warnings in third-party code.
 target_compile_options(libbacktrace_impl
   PRIVATE
     -Wno-unused-parameter
     -Wno-cast-function-type
 )

 # Create libbacktrace::libbacktrace as an IMPORTED INTERFACE library.
 # IMPORTED libraries don't get tracked for export, which is what we want
 # since libbacktrace is only used internally during build.
 # Threads::Threads is needed for pthread_once used in status_stack_trace.c.
 # CMAKE_DL_LIBS is needed for dladdr used in status_stack_trace.c.
 # On modern glibc (2.34+), dladdr is in libc, but older systems need libdl.
 add_library(libbacktrace_libbacktrace INTERFACE IMPORTED GLOBAL)
 target_link_libraries(libbacktrace_libbacktrace
   INTERFACE
     libbacktrace_impl
     Threads::Threads
     ${CMAKE_DL_LIBS}
 )
 target_include_directories(libbacktrace_libbacktrace
   INTERFACE $<BUILD_INTERFACE:${LIBBACKTRACE_SOURCE_DIR}>
 )
 target_compile_definitions(libbacktrace_libbacktrace
   INTERFACE IREE_HAVE_LIBBACKTRACE=1
 )
 add_library(libbacktrace::libbacktrace ALIAS libbacktrace_libbacktrace)
	# Copyright 2025 The IREE Authors
	#
	# Licensed under the Apache License v2.0 with LLVM Exceptions.
	# See https://llvm.org/LICENSE.txt for license information.
	# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

	# Build libbacktrace from source for Linux stack traces.
	# Uses FetchContent to pull upstream and provides our own CMake build.
	#
	# libbacktrace (https://github.com/ianlancetaylor/libbacktrace) provides
	# complete stack trace functionality including unwinding and symbol resolution
	# with file:line:function information.

	# Only build libbacktrace on Linux when enabled.
	# Other platforms have their own stack trace implementations:
	# - Windows: dbghelp
	# - macOS: backtrace+dladdr
	if(NOT CMAKE_SYSTEM_NAME STREQUAL "Linux" OR NOT IREE_ENABLE_LIBBACKTRACE)
	# Set empty target variable for consumers to use in DEPS.
	set(IREE_LIBBACKTRACE_TARGET "" CACHE INTERNAL "libbacktrace target (empty when disabled)")
	return()
	endif()

	# Set target variable for consumers to use in DEPS.
	set(IREE_LIBBACKTRACE_TARGET "libbacktrace::libbacktrace" CACHE INTERNAL "libbacktrace target")

	include(CheckSymbolExists)
	include(FetchContent)

	# pthreads is required for pthread_once used in status_stack_trace.c.
	find_package(Threads REQUIRED)

	# Suppress deprecation warning for FetchContent_Populate (CMake 4.x).
	# We use Populate because libbacktrace has no CMakeLists.txt.
	if(POLICY CMP0169)
	cmake_policy(SET CMP0169 OLD)
	endif()

	# Pin to a specific commit for reproducibility.
	set(LIBBACKTRACE_VERSION "b9e40069c0b47a722286b94eb5231f7f05c08713")

	FetchContent_Declare(
	libbacktrace_src
	GIT_REPOSITORY https://github.com/ianlancetaylor/libbacktrace.git
	GIT_TAG ${LIBBACKTRACE_VERSION}
	EXCLUDE_FROM_ALL
	)

	# Just populate, don't configure (upstream has no CMake).
	FetchContent_GetProperties(libbacktrace_src)
	if(NOT libbacktrace_src_POPULATED)
	FetchContent_Populate(libbacktrace_src)
	endif()
	set(LIBBACKTRACE_SOURCE_DIR "${libbacktrace_src_SOURCE_DIR}")

	# Detect dl_iterate_phdr availability at configure time.
	# This is critical for cross-compilation: the check uses the cross-toolchain
	# so it correctly detects target capabilities, not host.
	# - glibc: always has it
	# - musl: has it (with some quirks on older versions)
	# - uclibc-ng: depends on configuration
	# - newlib/other minimal libc: usually not
	set(CMAKE_REQUIRED_DEFINITIONS -D_GNU_SOURCE)
	check_symbol_exists(dl_iterate_phdr "link.h" LIBBACKTRACE_HAVE_DL_ITERATE_PHDR)
	unset(CMAKE_REQUIRED_DEFINITIONS)

	if(LIBBACKTRACE_HAVE_DL_ITERATE_PHDR)
	set(LIBBACKTRACE_DL_ITERATE_PHDR_DEF "#define HAVE_DL_ITERATE_PHDR 1")
	set(LIBBACKTRACE_LINK_H_DEF "#define HAVE_LINK_H 1")
	else()
	message(STATUS "libbacktrace: dl_iterate_phdr not found, shared library symbols won't be resolved")
	set(LIBBACKTRACE_DL_ITERATE_PHDR_DEF "/* dl_iterate_phdr not available */")
	set(LIBBACKTRACE_LINK_H_DEF "/* link.h not available */")
	endif()

	# Generate config.h with detected features.
	# Uses @VAR@ substitution for cross-compilation-safe detection.
	configure_file(
	${CMAKE_CURRENT_SOURCE_DIR}/config.h.in
	${LIBBACKTRACE_SOURCE_DIR}/config.h
	@ONLY
	)
	configure_file(
	${CMAKE_CURRENT_SOURCE_DIR}/backtrace-supported.h
	${LIBBACKTRACE_SOURCE_DIR}/backtrace-supported.h
	COPYONLY
	)
	# Copy our wrapper header that re-exports backtrace.h.
	# This provides a consistent include path for both CMake and Bazel builds,
	# allowing status_stack_trace.c to use <iree_libbacktrace.h>.
	configure_file(
	${CMAKE_CURRENT_SOURCE_DIR}/iree_libbacktrace.h
	${LIBBACKTRACE_SOURCE_DIR}/iree_libbacktrace.h
	COPYONLY
	)

	# Source files - include all platforms, let preprocessor handle selection.
	# Order matters for archive linking: implementations must come before stubs.
	# The linker picks the first symbol definition it finds when resolving from
	# an archive, so we list real implementations first and fallback stubs last.
	set(LIBBACKTRACE_SOURCES
	# Core files (always needed).
	${LIBBACKTRACE_SOURCE_DIR}/atomic.c
	${LIBBACKTRACE_SOURCE_DIR}/dwarf.c
	${LIBBACKTRACE_SOURCE_DIR}/fileline.c
	${LIBBACKTRACE_SOURCE_DIR}/posix.c
	${LIBBACKTRACE_SOURCE_DIR}/print.c
	${LIBBACKTRACE_SOURCE_DIR}/sort.c
	${LIBBACKTRACE_SOURCE_DIR}/state.c
	# Unwinding - real implementations before stub.
	${LIBBACKTRACE_SOURCE_DIR}/backtrace.c
	${LIBBACKTRACE_SOURCE_DIR}/simple.c
	${LIBBACKTRACE_SOURCE_DIR}/nounwind.c # Stub, must be after backtrace.c/simple.c.
	# Executable format - ELF/Mach-O/PE before unknown stub.
	${LIBBACKTRACE_SOURCE_DIR}/elf.c
	${LIBBACKTRACE_SOURCE_DIR}/macho.c
	${LIBBACKTRACE_SOURCE_DIR}/pecoff.c
	${LIBBACKTRACE_SOURCE_DIR}/unknown.c # Stub, must be after format files.
	# File I/O - mmap before read fallback.
	${LIBBACKTRACE_SOURCE_DIR}/mmap.c
	${LIBBACKTRACE_SOURCE_DIR}/mmapio.c
	${LIBBACKTRACE_SOURCE_DIR}/read.c # Fallback, must be after mmapio.c.
	)

	# Build libbacktrace as a STATIC library.
	# libbacktrace has multiple implementations of the same functions for different
	# platforms (e.g., elf.c vs pecoff.c vs macho.c). The autotools build selects
	# files at configure time, but we include all files and rely on archive linking
	# semantics - the linker only pulls in object files needed to resolve symbols,
	# so the first implementation wins and duplicates are ignored.
	add_library(libbacktrace_impl STATIC ${LIBBACKTRACE_SOURCES})
	target_include_directories(libbacktrace_impl
	PUBLIC $<BUILD_INTERFACE:${LIBBACKTRACE_SOURCE_DIR}>
	)
	target_compile_definitions(libbacktrace_impl
	PRIVATE _GNU_SOURCE # Required for dl_iterate_phdr on glibc.
	)
	# Suppress warnings in third-party code.
	target_compile_options(libbacktrace_impl
	PRIVATE
	-Wno-unused-parameter
	-Wno-cast-function-type
	)

	# Create libbacktrace::libbacktrace as an IMPORTED INTERFACE library.
	# IMPORTED libraries don't get tracked for export, which is what we want
	# since libbacktrace is only used internally during build.
	# Threads::Threads is needed for pthread_once used in status_stack_trace.c.
	# CMAKE_DL_LIBS is needed for dladdr used in status_stack_trace.c.
	# On modern glibc (2.34+), dladdr is in libc, but older systems need libdl.
	add_library(libbacktrace_libbacktrace INTERFACE IMPORTED GLOBAL)
	target_link_libraries(libbacktrace_libbacktrace
	INTERFACE
	libbacktrace_impl
	Threads::Threads
	${CMAKE_DL_LIBS}
	)
	target_include_directories(libbacktrace_libbacktrace
	INTERFACE $<BUILD_INTERFACE:${LIBBACKTRACE_SOURCE_DIR}>
	)
	target_compile_definitions(libbacktrace_libbacktrace
	INTERFACE IREE_HAVE_LIBBACKTRACE=1
	)
	add_library(libbacktrace::libbacktrace ALIAS libbacktrace_libbacktrace)