llvm-project/libc/cmake/modules/LLVMLibCObjectRules.cmake

293 lines
9.7 KiB
CMake

set(OBJECT_LIBRARY_TARGET_TYPE "OBJECT_LIBRARY")
# Rule which is essentially a wrapper over add_library to compile a set of
# sources to object files.
# Usage:
# add_object_library(
# <target_name>
# HDRS <list of header files>
# SRCS <list of source files>
# DEPENDS <list of dependencies>
# COMPILE_OPTIONS <optional list of special compile options for this target>
function(add_object_library target_name)
cmake_parse_arguments(
"ADD_OBJECT"
"" # No option arguments
"" # Single value arguments
"SRCS;HDRS;COMPILE_OPTIONS;DEPENDS" # Multivalue arguments
${ARGN}
)
if(NOT ADD_OBJECT_SRCS)
message(FATAL_ERROR "'add_object_library' rule requires SRCS to be specified.")
endif()
get_fq_target_name(${target_name} fq_target_name)
add_library(
${fq_target_name}
OBJECT
${ADD_OBJECT_SRCS}
${ADD_OBJECT_HDRS}
)
target_include_directories(
${fq_target_name}
PRIVATE
${LIBC_BUILD_DIR}/include
${LIBC_SOURCE_DIR}
${LIBC_BUILD_DIR}
)
if(ADD_OBJECT_COMPILE_OPTIONS)
target_compile_options(
${fq_target_name}
PRIVATE ${ADD_OBJECT_COMPILE_OPTIONS}
)
endif()
get_fq_deps_list(fq_deps_list ${ADD_OBJECT_DEPENDS})
if(fq_deps_list)
add_dependencies(${fq_target_name} ${fq_deps_list})
endif()
set_target_properties(
${fq_target_name}
PROPERTIES
"TARGET_TYPE" ${OBJECT_LIBRARY_TARGET_TYPE}
"OBJECT_FILES" "$<TARGET_OBJECTS:${fq_target_name}>"
"DEPS" "${fq_deps_list}"
)
endfunction(add_object_library)
set(ENTRYPOINT_OBJ_TARGET_TYPE "ENTRYPOINT_OBJ")
# A rule for entrypoint object targets.
# Usage:
# add_entrypoint_object(
# <target_name>
# [ALIAS|REDIRECTED] # Specified if the entrypoint is redirected or an alias.
# [NAME] <the C name of the entrypoint if different from target_name>
# SRCS <list of .cpp files>
# HDRS <list of .h files>
# DEPENDS <list of dependencies>
# COMPILE_OPTIONS <optional list of special compile options for this target>
# SPECIAL_OBJECTS <optional list of special object targets added by the rule `add_object`>
# )
function(add_entrypoint_object target_name)
cmake_parse_arguments(
"ADD_ENTRYPOINT_OBJ"
"ALIAS;REDIRECTED" # Optional argument
"NAME" # Single value arguments
"SRCS;HDRS;DEPENDS;COMPILE_OPTIONS" # Multi value arguments
${ARGN}
)
get_fq_target_name(${target_name} fq_target_name)
if(ADD_ENTRYPOINT_OBJ_ALIAS)
# Alias targets help one add aliases to other entrypoint object targets.
# One can use alias targets setup OS/machine independent entrypoint targets.
list(LENGTH ADD_ENTRYPOINT_OBJ_DEPENDS deps_size)
if(NOT (${deps_size} EQUAL "1"))
message(FATAL_ERROR "An entrypoint alias should have exactly one dependency.")
endif()
list(GET ADD_ENTRYPOINT_OBJ_DEPENDS 0 dep_target)
get_fq_dep_name(fq_dep_name ${dep_target})
if(NOT TARGET ${fq_dep_name})
message(WARNING "Aliasee ${fq_dep_name} for entrypoint alias ${target_name} missing; "
"Target ${target_name} will be ignored.")
return()
endif()
get_target_property(obj_type ${fq_dep_name} "TARGET_TYPE")
if((NOT obj_type) OR (NOT (${obj_type} STREQUAL ${ENTRYPOINT_OBJ_TARGET_TYPE})))
message(FATAL_ERROR "The aliasee of an entrypoint alias should be an entrypoint.")
endif()
add_custom_target(${fq_target_name})
add_dependencies(${fq_target_name} ${fq_dep_name})
get_target_property(object_file ${fq_dep_name} "OBJECT_FILE")
get_target_property(object_file_raw ${fq_dep_name} "OBJECT_FILE_RAW")
set_target_properties(
${fq_target_name}
PROPERTIES
"TARGET_TYPE" ${ENTRYPOINT_OBJ_TARGET_TYPE}
"IS_ALIAS" "YES"
"OBJECT_FILE" ""
"OBJECT_FILE_RAW" ""
"DEPS" "${fq_dep_name}"
)
return()
endif()
if(NOT ADD_ENTRYPOINT_OBJ_SRCS)
message(FATAL_ERROR "`add_entrypoint_object` rule requires SRCS to be specified.")
endif()
if(NOT ADD_ENTRYPOINT_OBJ_HDRS)
message(FATAL_ERROR "`add_entrypoint_object` rule requires HDRS to be specified.")
endif()
set(entrypoint_name ${target_name})
if(ADD_ENTRYPOINT_OBJ_NAME)
set(entrypoint_name ${ADD_ENTRYPOINT_OBJ_NAME})
endif()
set(objects_target_name "${fq_target_name}_objects")
add_library(
${objects_target_name}
# We want an object library as the objects will eventually get packaged into
# an archive (like libc.a).
OBJECT
${ADD_ENTRYPOINT_OBJ_SRCS}
${ADD_ENTRYPOINT_OBJ_HDRS}
)
target_compile_options(
${objects_target_name}
BEFORE
PRIVATE
-fpie ${LLVM_CXX_STD_default} -ffreestanding
)
target_include_directories(
${objects_target_name}
PRIVATE
${LIBC_BUILD_DIR}/include
${LIBC_SOURCE_DIR}
${LIBC_BUILD_DIR}
)
get_fq_deps_list(fq_deps_list ${ADD_ENTRYPOINT_OBJ_DEPENDS})
add_dependencies(
${objects_target_name}
libc.src.__support.common
${fq_deps_list}
)
if(ADD_ENTRYPOINT_OBJ_COMPILE_OPTIONS)
target_compile_options(
${objects_target_name}
PRIVATE ${ADD_ENTRYPOINT_OBJ_COMPILE_OPTIONS}
)
endif()
set(object_file_raw "${CMAKE_CURRENT_BINARY_DIR}/${target_name}_raw.o")
set(object_file "${CMAKE_CURRENT_BINARY_DIR}/${target_name}.o")
set(input_objects $<TARGET_OBJECTS:${objects_target_name}>)
add_custom_command(
OUTPUT ${object_file_raw}
DEPENDS ${input_objects}
COMMAND ${CMAKE_LINKER} -r ${input_objects} -o ${object_file_raw}
)
set(alias_attributes "0,function,global")
if(ADD_ENTRYPOINT_OBJ_REDIRECTED)
set(alias_attributes "${alias_attributes},hidden")
endif()
add_custom_command(
OUTPUT ${object_file}
# We llvm-objcopy here as GNU-binutils objcopy does not support the 'hidden' flag.
DEPENDS ${object_file_raw} ${llvm-objcopy}
COMMAND $<TARGET_FILE:llvm-objcopy> --add-symbol
"${entrypoint_name}=.llvm.libc.entrypoint.${entrypoint_name}:${alias_attributes}"
${object_file_raw} ${object_file}
)
add_custom_target(
${fq_target_name}
ALL
DEPENDS ${object_file}
)
set_target_properties(
${fq_target_name}
PROPERTIES
"TARGET_TYPE" ${ENTRYPOINT_OBJ_TARGET_TYPE}
"OBJECT_FILE" "${object_file}"
"OBJECT_FILE_RAW" "${object_file_raw}"
"DEPS" "${fq_deps_list}"
)
if(LLVM_LIBC_ENABLE_LINTING)
# We only want a second invocation of clang-tidy to run
# restrict-system-libc-headers if the compiler-resource-dir was set in
# order to prevent false-positives due to a mismatch between the host
# compiler and the compiled clang-tidy.
if(COMPILER_RESOURCE_DIR)
# We run restrict-system-libc-headers with --system-headers to prevent
# transitive inclusion through compler provided headers.
set(restrict_system_headers_check_invocation
COMMAND $<TARGET_FILE:clang-tidy> --system-headers
--checks="-*,llvmlibc-restrict-system-libc-headers"
# We explicitly set the resource dir here to match the
# resource dir of the host compiler.
"--extra-arg=-resource-dir=${COMPILER_RESOURCE_DIR}"
--quiet
-p ${PROJECT_BINARY_DIR}
${ADD_ENTRYPOINT_OBJ_SRCS}
)
else()
set(restrict_system_headers_check_invocation
COMMAND ${CMAKE_COMMAND} -E echo "Header file check skipped")
endif()
set(lint_timestamp "${CMAKE_CURRENT_BINARY_DIR}/.${target_name}.__lint_timestamp__")
add_custom_command(
OUTPUT ${lint_timestamp}
# --quiet is used to surpress warning statistics from clang-tidy like:
# Suppressed X warnings (X in non-user code).
# There seems to be a bug in clang-tidy where by even with --quiet some
# messages from clang's own diagnostics engine leak through:
# X warnings generated.
# Until this is fixed upstream, we use -fno-caret-diagnostics to surpress
# these.
COMMAND $<TARGET_FILE:clang-tidy>
"--extra-arg=-fno-caret-diagnostics" --quiet
# Path to directory containing compile_commands.json
-p ${PROJECT_BINARY_DIR}
${ADD_ENTRYPOINT_OBJ_SRCS}
# See above: this might be a second invocation of clang-tidy depending on
# the conditions above.
${restrict_system_headers_check_invocation}
# We have two options for running commands, add_custom_command and
# add_custom_target. We don't want to run the linter unless source files
# have changed. add_custom_target explicitly runs everytime therefore we
# use add_custom_command. This function requires an output file and since
# linting doesn't produce a file, we create a dummy file using a
# crossplatform touch.
COMMAND "${CMAKE_COMMAND}" -E touch ${lint_timestamp}
COMMENT "Linting... ${target_name}"
DEPENDS ${clang-tidy} ${objects_target_name} ${ADD_ENTRYPOINT_OBJ_SRCS}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
)
add_custom_target(${fq_target_name}.__lint__
DEPENDS ${lint_timestamp})
add_dependencies(lint-libc ${fq_target_name}.__lint__)
add_dependencies(${fq_target_name} ${fq_target_name}.__lint__)
endif()
endfunction(add_entrypoint_object)
# Rule build a redirector object file.
function(add_redirector_object target_name)
cmake_parse_arguments(
"REDIRECTOR_OBJECT"
"" # No optional arguments
"SRC" # The cpp file in which the redirector is defined.
"" # No multivalue arguments
${ARGN}
)
if(NOT REDIRECTOR_OBJECT_SRC)
message(FATAL_ERROR "'add_redirector_object' rule requires SRC option listing one source file.")
endif()
add_library(
${target_name}
OBJECT
${REDIRECTOR_OBJECT_SRC}
)
target_compile_options(
${target_name}
BEFORE PRIVATE -fPIC
)
endfunction(add_redirector_object)