介绍
CMake有许多内置配置，可用于编译项目。它们指定优化级别以及二进制文件中是否包含调试信息。
提供的级别为：
- Release - Adds the
-O3 -DNDEBUGflags to the compiler - Debug - Adds the
-gflag - MinSizeRel - Adds
-Os -DNDEBUG - RelWithDebInfo - Adds
-O2 -g -DNDEBUGflags
本教程中的文件包括：
$ tree
.
├── CMakeLists.txt
├── main.cpp
- CMakeLists.txt - 包含要运行的CMake命令
- main.cpp - main文件
概念
设置构建类型
用如下方法设置构建类型：
Using a gui tool such as ccmake / cmake-gui
Passing into cmake
cmake .. -DCMAKE_BUILD_TYPE=Release
设置默认构建类型
CMake提供的默认构建类型是不包含用于优化的编译器标志。对于某些项目，您可能需要设置默认生成类型，以便不必记住设置它。
为此，您可以将以下内容添加到CMakeLists.txt文件顶层
if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
message("Setting build type to 'RelWithDebInfo' as none was specified.")
set(CMAKE_BUILD_TYPE RelWithDebInfo CACHE STRING "Choose the type of build." FORCE)
# Set the possible values of build type for cmake-gui
set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release"
"MinSizeRel" "RelWithDebInfo")
endif()
构建例子
$ mkdir build
$ cd build/
$ cmake ..
Setting build type to 'RelWithDebInfo' as none was specified.
-- The C compiler identification is GNU 4.8.4
-- The CXX compiler identification is GNU 4.8.4
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build
$ make VERBOSE=1
/usr/bin/cmake -H/home/matrim/workspace/cmake-examples/01-basic/F-build-type -B/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
make -f CMakeFiles/cmake_examples_build_type.dir/build.make CMakeFiles/cmake_examples_build_type.dir/depend
make[2]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
cd /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/matrim/workspace/cmake-examples/01-basic/F-build-type /home/matrim/workspace/cmake-examples/01-basic/F-build-type /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/DependInfo.cmake --color=
Dependee "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/DependInfo.cmake" is newer than depender "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/depend.internal".
Dependee "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/depend.internal".
Scanning dependencies of target cmake_examples_build_type
make[2]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
make -f CMakeFiles/cmake_examples_build_type.dir/build.make CMakeFiles/cmake_examples_build_type.dir/build
make[2]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
/usr/bin/cmake -E cmake_progress_report /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles 1
[100%] Building CXX object CMakeFiles/cmake_examples_build_type.dir/main.cpp.o
/usr/bin/c++ -O2 -g -DNDEBUG -o CMakeFiles/cmake_examples_build_type.dir/main.cpp.o -c /home/matrim/workspace/cmake-examples/01-basic/F-build-type/main.cpp
Linking CXX executable cmake_examples_build_type
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmake_examples_build_type.dir/link.txt --verbose=1
/usr/bin/c++ -O2 -g -DNDEBUG CMakeFiles/cmake_examples_build_type.dir/main.cpp.o -o cmake_examples_build_type -rdynamic
make[2]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
/usr/bin/cmake -E cmake_progress_report /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles 1
[100%] Built target cmake_examples_build_type
make[1]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
/usr/bin/cmake -E cmake_progress_start /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles 0$ mkdir build
$ cd build/
/build$ cmake ..
Setting build type to 'RelWithDebInfo' as none was specified.
-- The C compiler identification is GNU 4.8.4
-- The CXX compiler identification is GNU 4.8.4
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build
/build$ make VERBOSE=1
/usr/bin/cmake -H/home/matrim/workspace/cmake-examples/01-basic/F-build-type -B/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
make -f CMakeFiles/cmake_examples_build_type.dir/build.make CMakeFiles/cmake_examples_build_type.dir/depend
make[2]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
cd /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/matrim/workspace/cmake-examples/01-basic/F-build-type /home/matrim/workspace/cmake-examples/01-basic/F-build-type /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/DependInfo.cmake --color=
Dependee "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/DependInfo.cmake" is newer than depender "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/depend.internal".
Dependee "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles/cmake_examples_build_type.dir/depend.internal".
Scanning dependencies of target cmake_examples_build_type
make[2]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
make -f CMakeFiles/cmake_examples_build_type.dir/build.make CMakeFiles/cmake_examples_build_type.dir/build
make[2]: Entering directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
/usr/bin/cmake -E cmake_progress_report /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles 1
[100%] Building CXX object CMakeFiles/cmake_examples_build_type.dir/main.cpp.o
/usr/bin/c++ -O2 -g -DNDEBUG -o CMakeFiles/cmake_examples_build_type.dir/main.cpp.o -c /home/matrim/workspace/cmake-examples/01-basic/F-build-type/main.cpp
Linking CXX executable cmake_examples_build_type
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmake_examples_build_type.dir/link.txt --verbose=1
/usr/bin/c++ -O2 -g -DNDEBUG CMakeFiles/cmake_examples_build_type.dir/main.cpp.o -o cmake_examples_build_type -rdynamic
make[2]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
/usr/bin/cmake -E cmake_progress_report /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles 1
[100%] Built target cmake_examples_build_type
make[1]: Leaving directory `/home/matrim/workspace/cmake-examples/01-basic/F-build-type/build'
/usr/bin/cmake -E cmake_progress_start /home/matrim/workspace/cmake-examples/01-basic/F-build-type/build/CMakeFiles 0
