CMake中set_target_properties/get_target_property的使用

Posted 2022-12-16 fengbingchun

      CMake中的set_target_properties命令用于为targets设置属性(targets can have properties that affect how they are built)，其格式如下：

set_target_properties(target1 target2 ...
                      PROPERTIES prop1 value1
                      prop2 value2 ...)

      该命令的语法是列出要更改的所有targets，然后提供接下来要设置的值。你可以使用任何所需的prop值对，然后使用get_property或 get_target_property命令将其提取。

      CMake中的get_target_property命令用于从target获取属性，其格式如下：

get_target_property(<VAR> target property)

      属性的值存储在变量<VAR>中。如果没有找到target属性，则行为取决于是否已将其定义为INHERITED属性。非继承(inherited)的属性将设置<VAR>为<VAR>-NOTFOUND，而继承的属性将搜索相关的父作用域(parent scope),如define_property所述，如果仍然无法找到属性，<VAR>将被设置为空字符串。
      使用set_target_properties来设置target属性值。属性通常用于控制如何构建target，但有些属性用于查询target。该命令可以获取到目前为止创建的任何target的属性。targets不需要在当前CMakeLists.txt文件中。

include_directories(include)
add_library(add STATIC source/add.cpp)
add_library(subtraction SHARED source/subtraction.cpp)
add_library(multipy OBJECT source/multipy.cpp)

set_target_properties(add subtraction multipy PROPERTIES _ADD_ static _SUBTRACTION_ shared _MULTIPY_ object)

get_target_property(var add _ADD_)
message("var: $var") # var: static
get_target_property(var subtraction _SUBTRACTION_)
message("var: $var") # var: shared
get_target_property(var multipy _MULTIPY_)
message("var: $var") # var: object

get_target_property(var add XXXX)
message("var: $var") # var: var-NOTFOUND

      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)

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_set_target_properties.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