Cmake learning and use notes (1)

Catalog

Using tools ：

Project settings ：

Build the program

problem ： To be solved ？---- Solved

set Set a variable ------------------------- Add version number

Set the system's own variables

Set custom variables

Add version number

Expand ：

 add_definitions------------------------- Add macro definition

---

Using tools ：

vs 2019, Clion

System ： Windows

Refer to the website ：cmake Use the tutorial （ One ）- start - Nuggets

Project settings ：

project(<PROJECT-NAME> [VERSION <major>[.<minor>[.<patch>[.<tweak>]]]] [LANGUAGES <language-name>...])

You can only set the project name ： Such as ：

project ("cPulsPlusTestProject")

  You can also set the item description , Project address, etc

project (cPulsPlusTestPrj 
		VERSION 1.0.0 
		DESCRIPTION " Project description ：xxxxx"
		HOMEPAGE_URL " Project address , such as :github  Address "
		LANGUAGES CXX)

  Be careful ： The above code fragment must be capitalized , Otherwise, the compilation will not pass , such as （LANGUAGES  CXX, DESCRIPTION etc. ）

Build the program

Use cmake To build programs ：

  Use cmake .

Before building ：

  After construction ：

  But I use it clion The built program always defaults to vs 2019

After construction ：

  If you want to re cmake  , Need to delete cache

 make  

windows Prompt make Not an internal command ​
If you use MinGW, Yours make  It's called  mingw32-make

If you use MSVC, Yours make It's called  nmake

problem ： To be solved ？---- Solved

cmake .  Always default to vs2019

Suspected ： Not understanding cmake Back point （.） What does that mean?

After testing, it should be the path , It should be exactly CMakeList.txt The position of , therefore I should be ../  Return to upper level

  Always use the upper path , therefore cmake come out Always default to vs 2019 

  When I enter mingw Next , What we build is not vs 2019 The environment ： Such as ：

set Set a variable ------------------------- Add version number

set(KEY VALUE) Take two parameters , Used to declare variables . stay camke Use... In grammar KEY You can't get... Directly VALUE, You have to use ${KEY} This way of writing to get VALUE.

Set the system's own variables

Such as ：C++ standard

set(cmake_cxx_standard 11)

Set custom variables

Set custom variables , for example ： Set the header file search path

CMAKE_CURRENT_SOURCE_DIR
This is the currently processed CMakeLists.txt directory

Add version number

First set two variables

set (cPlusPlusTest_version_major 1)
set (cPlusPlusTest_version_minor 0)

configure_file(
    "${PROJECT_SOURCE_DIR}/cPlusPlusTestConfig.h.in"
    "${PROJECT_BINARY_DIR}/cPlusPlusTestConfig.h"
)

stay cPlusPlusTestConfig.h.in Add

#define cPlusPlusTest_version_major @[email protected]
#define cPlusPlusTest_version_minor @[email protected]

  Use

Expand ：

configure_file(input output options)

   Put a file ( from input Parameter assignment ) Copy to the specified location ( from output Parameter assignment ), And according to options Modify its contents .

configure_file Commands are generally used to customize compilation options or customize macro scenarios .configure_file The order will be based on options Specified rule ：

• COPYONLY： Just copy files , Don't do any variable substitution . This option specifies NEWLINE_STYLE Option cannot be used （ Invalid ）.
• ESCAPE_QUOTES： Avoid any backslash (C style ) escape .

   take input File copy to output file , And the variables in the input file content , Replace the reference with @[email protected] or ${VAR} Variable value . Each variable reference will be replaced with the current value of the variable , If the variable is not defined , Is an empty string .

  for example ：cPlusPlusTestConfig.h.in

1. Definition CMakeList.txt

set (cPlusPlusTest_version_major 1.9)
set (cPlusPlusTest_version_minor 0)
configure_file(
	"${PROJECT_SOURCE_DIR}/cPlusPlusTestConfig.h.in"
	"${PROJECT_BINARY_DIR}/cPlusPlusTestConfig.h"
)

2. cPlusPlusTestConfig.h.in（ Input file ）

#define cPlusPlusTest_version_major @[email protected]
#define cPlusPlusTest_version_minor @[email protected]

3. cPlusPlusTestConfig.h（ The output file ）

Automatic generation , There is no need for us to manually input           

PROJECT_BINARY_DIR： The official explanation is The full path used to generate the project directory

for example ：

PROJECT_SOURCE_DIR： PROJECT_SOURCE_DIR Include for PROJECT() The most recent CMakeLists.txt The folder where the file is located .

for example ： The inner layer of the CMakeLists.txt Medium not included project()

An error will occur   Tell me the file doesn't exist  

  I put it on the outer layer , There is no error

 add_definitions------------------------- Add macro definition

Add one flag For pretreatment

There are two ways to add ：

• -D start
• /D start

for example ：add_definitions(-DMyDebug)

  Use ：

  Be careful ： Do not use the front -D