CMake中的define_property命令用于定义和记录自定义属性,其格式如下:
define_property(<GLOBAL | DIRECTORY | TARGET | SOURCE |
TEST | VARIABLE | CACHED_VARIABLE>
PROPERTY <name> [INHERITED]
[BRIEF_DOCS <brief-doc> [docs...]]
[FULL_DOCS <full-doc> [docs...]]
[INITIALIZE_FROM_VARIABLE <variable>])
在作用域内定义一个属性以与set_property和get_property命令一起使用。它主要用于定义属性初始化或继承(initialized or inherited)的方式。从历史上看,该命令还将文档(documentation )与属性关联,但这不再被视为主要用例。
第一个参数决定了该属性被使用的作用域类型(kind of scope)。它必须是以下之一:
GLOBAL = associated with the global namespace
DIRECTORY = associated with one directory
TARGET = associated with one target
SOURCE = associated with one source file
TEST = associated with a test named with add_test
VARIABLE = documents a CMake language variable
CACHED_VARIABLE = documents a CMake cache variable
注意:与set_property和get_property命令不同,不需要给出实际作用域;只有作用域类型是重要的。
必需的PROPERTY选项紧跟要定义的属性的名称。
如果给出了INHERITED选项,则当请求的属性(requested property)未在给定命令的作用域内设置时,get_property命令将链接到下一个更高的作用域。
注意:此作用域链接行为仅适用于对get_property, get_directory_property, get_target_property, get_source_file_property和get_test_property命令的调用。设置属性时没有继承行为,因此将APPEND或APPEND_STRING和set_property命令一起使用在计算要追加到的内容时不会考虑继承的值。
BRIEF_DOCS和FULL_DOCS选项后跟与属性关联的字符串,作为其简短和完整的文档(brief and full documentation).CMake不使用此文档,只是通过get_property命令的相应选项将其提供给项目(project).
INITIALIZE_FROM_VARIABLE选项指定初始化属性的变量。它只能用于target属性。<variable>名称必须以属性名称结尾,并且不能以CMAKE_或_CMAKE_开头。属性名称必须至少包含一个下划线。建议属性名称具有特定于项目的前缀。
# 3.23版本BRIEF_DOCS和FULL_DOCS选项是可选的
define_property(GLOBAL PROPERTY pro_global
BRIEF_DOCS "A test property"
FULL_DOCS "A long description of this test property"
)
if(pro_global)
message("define property") # won't print
endif()
get_property(global_result GLOBAL PROPERTY pro_global DEFINED)
if(global_result)
message("global property: ${global_result}") # global property: 1
endif()
define_property(TARGET PROPERTY pro_target
BRIEF_DOCS "A test property"
FULL_DOCS "A long description of this test property"
)
get_property(target_result TARGET PROPERTY pro_target DEFINED)
if(target_result)
message("target property: ${target_result}") # target property: 1
include_directories(include)
add_library(add STATIC source/add.cpp)
set_target_properties(add PROPERTIES pro_target xxxx)
get_target_property(var add pro_target)
message("var: ${var}") # var: xxxx
endif()
执行测试代码需要多个文件:
build.sh内容如下:
#! /bin/bash
# supported input parameters(cmake commands)
params=(function macro cmake_parse_arguments \
find_library find_path find_file find_program find_package \
cmake_policy cmake_minimum_required project include \
string list set foreach message option if while return \
math file configure_file \
include_directories add_executable add_library target_link_libraries install \
target_sources add_custom_command add_custom_target \
add_subdirectory aux_source_directory \
set_property set_target_properties define_property \
add_definitions target_compile_definitions)
usage()
{
echo "Error: $0 needs to have an input parameter"
echo "supported input parameters:"
for param in ${params[@]}; do
echo " $0 ${param}"
done
exit -1
}
if [ $# != 1 ]; then
usage
fi
flag=0
for param in ${params[@]}; do
if [ $1 == ${param} ]; then
flag=1
break
fi
done
if [ ${flag} == 0 ]; then
echo "Error: parameter \"$1\" is not supported"
usage
exit -1
fi
if [[ ! -d "build" ]]; then
mkdir build
cd build
else
cd build
fi
echo "==== test $1 ===="
# test_set.cmake: cmake -DTEST_CMAKE_FEATURE=$1 --log-level=verbose ..
# test_option.cmake: cmake -DTEST_CMAKE_FEATURE=$1 -DBUILD_PYTORCH=ON ..
cmake -DTEST_CMAKE_FEATURE=$1 ..
# It can be executed directly on the terminal, no need to execute build.sh, for example: cmake -P test_set.cmake
make
# make install # only used in cmake files with install command
CMakeLists.txt内容如下:
cmake_minimum_required(VERSION 3.22)
project(cmake_feature_usage)
message("#### current cmake version: ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}.${CMAKE_PATCH_VERSION}")
include(test_${TEST_CMAKE_FEATURE}.cmake)
message("==== test finish ====")
test_define_property.cmake内容为上面的所有测试代码段
另外还包括三个目录:include,source,samples,它们都是非常简单的实现,仅用于测试,如下:
可能的执行结果如下图所示:
GitHub: https://github.com/fengbingchun/Linux_Code_Test