Shulou(Shulou.com)06/03 Report--

In this issue, the editor will bring you what are the learning points of cmake in c language. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

1 set

Set (var hello) message (${var})

Output

Hello

In fact, not only output hello, there is a lot of other information, will generate a lot of files

Files

2 CMAKE_C (XX) _ FLAGS

The contents of the variable CMAKE_C_FLAGS are passed to the C compiler, which acts on all compiled configurations. If you want to be valid for only one specific configuration, you can set CMAKE_C_FLAGS_, such as CMAKE_C_FLAGS_RELEASE, CMAKE_C_FLAGS_DEBUG.

Set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS}-Wall-O3-march=native-Wno-reorder")

Set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}-Wall-O3-march=native-Wno-reorder")

Optimization of compilation option-Wall O3

Other internal variables:

CMAKE_C_COMPILER: specifies the C compiler

CMAKE_CXX_COMPILER:

CMAKE_C_FLAGS: options for compiling C files, such as-g; you can also add compilation options through add_definitions

EXECUTABLE_OUTPUT_PATH: the path to the executable file

LIBRARY_OUTPUT_PATH: library file path

CMAKE_BUILD_TYPE::build type (Debug, Release,...)

CMAKE_BUILD_TYPE=Debug

BUILD_SHARED_LIBS:Switch between shared and static libraries

Use of built-in variables:

Specified in CMakeLists.txt, using set

Used in the cmake command, such as cmake-DBUILD_SHARED_LIBS=OFF

3 CHECK_CXX_COMPILER_FLAG

Check whether the CXX compiler supports the given flag

Must first include (CheckCXXCompilerFlag)

Include (CheckCXXCompilerFlag)

CHECK_CXX_COMPILER_FLAG ()

E.g.

CHECK_CXX_COMPILER_FLAG ("- std=c++11" COMPILER_SUPPORTS_CXX11) CHECK_CXX_COMPILER_FLAG ("- std=c++0x" COMPILER_SUPPORTS_CXX0X) if (COMPILER_SUPPORTS_CXX11) set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}-std=c++11") add_definitions (- DCOMPILEDWITHC11) message (STATUS "Using flag-std=c++11.") Elseif (COMPILER_SUPPORTS_CXX0X) set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}-std=c++0x") add_definitions (- DCOMPILEDWITHC0X) message (STATUS "Using flag-std=c++0x.") else () message (FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no containers 11 support. Please use a different C++ compiler.") endif ()

The above code is straightforward.

Is to check whether the current compiler supports cymbals 11

The var assigned by CHECK_CXX_COMPILER_FLAG is of Bool type.

4 add_definitions

Add compilation parameters

Add_definitions (- DDEBUG)

The DEBUG macro definition will be added to the gcc command line, so you can face the DEBUG macro in your source file.

5 ENV

Syntax:

$ENV (VAR) # reads the environment variable VAR and can also assign a value to it with set

Eg:

IF (DEFINED ENV {ARM_ARCHITECTURE}) # if it is an arm machine

6 list

List operation

List (LENGTH) list (GET [...]) list (APPEND [...]) list (FIND) list (INSERT [...]) list (REMOVE_ITEM [...]) list (REMOVE_AT [...]) list (REMOVE_DUPLICATES) list (REVERSE) list (SORT)

APPEND appends elements, see? these are all operations of list.

7 CMAKE_MODULE_PATH

The list of the modules searched by cmake, which is a list

8 find_package

This is a little complicated. Let's just look at the official documents.

And this

9 include_directories

Increase the search path of the header file, which is equivalent to specifying the-I parameter of gcc

Include_directories ([AFTER | BEFORE] [SYSTEM] dir1 [dir2...])

10 add_library

Add_library ([STATIC | SHARED | MODULE]

[EXCLUDE_FROM_ALL]

Source1 [source2...])

Add the directory of the library

11 target_link_libraries

Target_link_libraries ([item1 [item2 [...]

[[debug | optimized | general]].)

The directive target_link_libraries () is used to specify the libraries that target needs to link to, and there are different options.

E.g.

Target_link_libraries (myapp debug-labc optimized-lxyz)

Myapp links libabc.an in debug build and libxyz.an in release build, and their directories are added by the add_library command

12 add_executable

Add executable files (from source files)

Add_executable ([WIN32] [MACOSX_BUNDLE])

[EXCLUDE_FROM_ALL]

Source1 [source2...])

E.g.

Add_executable (stereo_euroc Examples/Stereo/stereo_euroc.cc) target_link_libraries (stereo_euroc ${PROJECT_NAME})

Stereo_euroc is the executable file to be generated, and the source code is the later .cc file. Link to the following libraries.

These are the learning points of cmake in the c language shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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