2022年6月25日 星期六

CMake - Step 2: Adding A Library As An Option


很多時候我們會在專案中決定使用哪個library, 這裡會舉個範例, 使用自訂的library或是使用系統的library,首先要在最上層的CMakeLists.txt中用option()定義我們的變數USE_MYMATH, on代表用自訂的library, 否則用系統的library, 所以相對應的target_link_libraries()與target_include_directories()也要根據USE_MYMATH稍微做一下調整, 所以我們用EXTRA_LIBS與EXTRA_INCLUDES分別去儲存對應的header file位置與相關的library資訊
# Require a minimum version of cmake.
# cmake_minimum_required(VERSION <min>>[...<policy_max>] [FATAL_ERROR])
cmake_minimum_required(VERSION 3.10)

# Set the name of the project.
# project(<PROJECT-NAME< [<anguage-name>...])
# project(<PROJECT-NAME>
#         [VERSION <major>[.<minor>[.<patch>[.<tweak>]]]]
#         [DESCRIPTION <project-description-string>]
#         [LANGUAGES <language-name>...])
project(Tutorial VERSION 0.1.2.3 DESCRIPTION "This is Brook 1st CMake Lib")

# Add an executable to the project using the specified source files.
# add_executable(<name> [WIN32] [MACOSX_BUNDLE]
#                [EXCLUDE_FROM_ALL]
#                [source1] [source2 ...])
add_executable(Tutorial hello.c)

# option(<variable> "<help_text>" [value])
option(USE_MYMATH "Use tutorial provided math implementation" ON)

# configure_file(<input> <output>
#               [NO_SOURCE_PERMISSIONS | USE_SOURCE_PERMISSIONS |
#                FILE_PERMISSIONS <permissions>...]
#               [COPYONLY] [ESCAPE_QUOTES] [@ONLY]
#               [NEWLINE_STYLE [UNIX|DOS|WIN32|LF|CRLF] ])
# configure a header file to pass some of the CMake settings
# to the source code
configure_file(Config.h.in Config.h)

if (USE_MYMATH)
# Add a subdirectory to the build.
# add_subdirectory(source_dir [binary_dir]
#                        [EXCLUDE_FROM_ALL])
add_subdirectory(mymath01)

# list(APPEND <list> [<element> ...])
# Appends elements to the list.
# If no variable named <list> exists in the current
# scope its value is treated as empty and the elements
# are appended to that empty list.
list(APPEND EXTRA_LIBS MyMathLib1)
list(APPEND EXTRA_INCLUDES "${PROJECT_SOURCE_DIR}/mymath01")
else()
list(APPEND EXTRA_LIBS "m")
endif()

# Specify libraries or flags to use when linking a given target and/or its dependents.
# target_link_libraries(<target>
#                      <PRIVATE|PUBLIC|INTERFACE> ...
#                      [<PRIVATE|PUBLIC|INTERFACE> ...]...)
target_link_libraries(Tutorial PUBLIC ${EXTRA_LIBS})

# Add include directories to a target.
# target_include_directories(&;lt;target> [SYSTEM] [AFTER|BEFORE]
#   &;lt;INTERFACE|PUBLIC|PRIVATE> [items1...]
#   [&;lt;INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
target_include_directories(Tutorial PUBLIC "${PROJECT_BINARY_DIR}" ${EXTRA_INCLUDES})

接著會利用Config.h.in的cmakedefine去define USE_MYMATH, hello.c則需要include "Config.h"並且利用#ifdef/#else/#endif做一些對應的修改
[brook@:~/Projects/cmake/02-2]$ tree
.
`-- src
    |-- CMakeLists.txt
    |-- Config.h.in
    |-- hello.c
    `-- mymath01
        |-- CMakeLists.txt
        |-- mymath01.c
        `-- mymath01.h

2 directories, 6 files
[brook@:~/Projects/cmake/02-2]$ cat src/Config.h.in
#cmakedefine USE_MYMATH
[brook@:~/Projects/cmake/02-2]$ cat src/hello.c
#include <stdio.h>
#include <stdlib.h>
#include "Config.h"

#ifdef USE_MYMATH
#pragma message("use mymath")
#include "mymath01.h"
#else
#pragma message("use system")
#include 
#endif

int main(int argc, char *argv[])
{
#ifdef USE_MYMATH
        printf("mymath: %d\n", squar(atoi(argv[1])));
#else
        printf("system: %d\n", (int)pow(atoi(argv[1]), 2));
#endif
        return 0;
}

[brook@:~/Projects/cmake/02-2/build]$ cmake ../src
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- 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
-- Detecting C compile features
-- Detecting C compile features - 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
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /build/brook/Projects/cmake/02-2/build
[brook@:~/Projects/cmake/02-2/build]$ make
Scanning dependencies of target MyMathLib1
[ 25%] Building C object mymath01/CMakeFiles/MyMathLib1.dir/mymath01.c.o
[ 50%] Linking C static library libMyMathLib1.a
[ 50%] Built target MyMathLib1
Scanning dependencies of target Tutorial
[ 75%] Building C object CMakeFiles/Tutorial.dir/hello.c.o
/build/brook/Projects/cmake/02-2/src/hello.c:6:9: note: #pragma message: use mymath
 #pragma message("use mymath")
         ^~~~~~~
[100%] Linking C executable Tutorial
[100%] Built target Tutorial
[brook@:~/Projects/cmake/02-2/build]$ ./Tutorial 3
mymath: 9
[brook@:~/Projects/cmake/02-2/build]$ cmake ../src/ -DUSE_MYMATH=off
-- Configuring done
-- Generating done
-- Build files have been written to: /build/brook/Projects/cmake/02-2/build
[brook@:~/Projects/cmake/02-2/build]$ make
Scanning dependencies of target Tutorial
[ 50%] Building C object CMakeFiles/Tutorial.dir/hello.c.o
/build/brook/Projects/cmake/02-2/src/hello.c:9:9: note: #pragma message: use system
 #pragma message("use system")
         ^~~~~~~
[100%] Linking C executable Tutorial
[100%] Built target Tutorial
[brook@:~/Projects/cmake/02-2/build]$ ./Tutorial 3
system: 9





2022年6月19日 星期日

CMake - Step 2: Adding a Library


這篇主要要談如何建立一個library, 首先我們再src底下創建目錄mymath01用來放置我們的library, 裡面的soucre code包含mymath01.c與mymath01.h, 所以src/CMakeList.txt需要用add_subdirectory(mymath01)告訴CMake要編譯src/mymath01, 而src/mymath01/CMakeList.txt需要描述如何編譯Library, 主要是用add_library()告訴CMake這個library要用哪些source code編譯.
[brook@:~/Projects/cmake/02]$ tree
.
`-- src
    |-- CMakeLists.txt
    `-- mymath01
        |-- CMakeLists.txt
        |-- mymath01.c
        `-- mymath01.h

2 directories, 4 files
[brook@:~/Projects/cmake/02]$ cat src/CMakeLists.txt
# Require a minimum version of cmake.
# cmake_minimum_required(VERSION <min>>[...<policy_max>] [FATAL_ERROR])
cmake_minimum_required(VERSION 3.10)

# Set the name of the project.
# project(<PROJECT-NAME< [<anguage-name>...])
# project(<PROJECT-NAME>
#         [VERSION <major>[.<minor>[.<patch>[.<tweak>]]]]
#         [DESCRIPTION <project-description-string>]
#         [LANGUAGES <language-name>...])
project(Tutorial VERSION 0.1.2.3 DESCRIPTION "This is Brook 1st CMake Lib")

# Add a subdirectory to the build.
# add_subdirectory(source_dir [binary_dir]
#                        [EXCLUDE_FROM_ALL])
add_subdirectory(mymath01)


[brook@:~/Projects/cmake/02]$ cat src/mymath01/CMakeLists.txt
# Add a library to the project using the specified source files.
# add_library( [STATIC | SHARED | MODULE]
#             [EXCLUDE_FROM_ALL]
#                       source1 [source2 ...])
add_library(MyMathLib1 mymath01.c)

[brook@:~/Projects/cmake/02]$ cat src/mymath01/mymath01.h
#ifndef MYMATH01_H
#define MYMATH01_H

int squar(int a);

#endif
[brook@:~/Projects/cmake/02]$ cat src/mymath01/mymath01.c
#include "mymath01.h"

int squar(int a)
{
  return a*a;
}

[brook@:~/Projects/cmake/02]$ mkdir build && cd build
[brook@:~/Projects/cmake/02/build]$ cmake ../src/
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- 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
-- Detecting C compile features
-- Detecting C compile features - 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
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /build/brook/Projects/cmake/02/build
[brook@:~/Projects/cmake/02/build]$ cmake --build .
Scanning dependencies of target MyMathLib1
[ 50%] Building C object mymath01/CMakeFiles/MyMathLib1.dir/mymath01.c.o
[100%] Linking C static library libMyMathLib1.a
[100%] Built target MyMathLib1
[brook@:~/Projects/cmake/02/build]$ ls
CMakeCache.txt  CMakeFiles  Makefile  cmake_install.cmake  mymath01
[brook@:~/Projects/cmake/02/build]$ ls mymath01/
CMakeFiles  Makefile  cmake_install.cmake  libMyMathLib1.a
[brook@:~/Projects/cmake/02/build]$ nm mymath01/libMyMathLib1.a

mymath01.c.o:
0000000000000000 T squar

接著我們結合"Step 1"學的創建一個hello.c來引用MyMathLib1, 我們要用target_link_libraries()將MyMathLib1 link進來.
[brook@:~/Projects/cmake/02]$ tree
.
`-- src
    |-- CMakeLists.txt
    |-- hello.c
    `-- mymath01
        |-- CMakeLists.txt
        |-- mymath01.c
        `-- mymath01.h

2 directories, 5 files

[brook@:~/Projects/cmake/02]$ cat src/CMakeLists.txt
# Require a minimum version of cmake.
# cmake_minimum_required(VERSION <min>>[...<policy_max>] [FATAL_ERROR])
cmake_minimum_required(VERSION 3.10)

# Set the name of the project.
# project(<PROJECT-NAME< [<anguage-name>...])
# project(<PROJECT-NAME>
#         [VERSION <major>[.<minor>[.<patch>[.<tweak>]]]]
#         [DESCRIPTION <project-description-string>]
#         [LANGUAGES <language-name>...])
project(Tutorial VERSION 0.1.2.3 DESCRIPTION "This is Brook 1st CMake Lib")

# Add an executable to the project using the specified source files.
# add_executable(<name> [WIN32] [MACOSX_BUNDLE]
#                [EXCLUDE_FROM_ALL]
#                [source1] [source2 ...])
add_executable(Tutorial hello.c)

# Specify libraries or flags to use when linking a given target and/or its dependents.
# target_link_libraries(<target>
#                      <PRIVATE|PUBLIC|INTERFACE> ...
#                      [<PRIVATE|PUBLIC|INTERFACE> ...]...)
target_link_libraries(Tutorial PUBLIC MyMathLib1)

# Add include directories to a target.
# target_include_directories(&;lt;target> [SYSTEM] [AFTER|BEFORE]
#   &;lt;INTERFACE|PUBLIC|PRIVATE> [items1...]
#   [&;lt;INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
target_include_directories(Tutorial PUBLIC "${PROJECT_SOURCE_DIR}/mymath01")

# Add a subdirectory to the build.
# add_subdirectory(source_dir [binary_dir]
#                        [EXCLUDE_FROM_ALL])
add_subdirectory(mymath01)

[brook@:~/Projects/cmake/02]$ cat src/hello.c
#include <stdio.h>
#include <stdlib.h>
#include "mymath01.h"

int main(int argc, char *argv[])
{
  printf("%d\n", squar(atoi(argv[1])));
  return 0;
}
[brook@:~/Projects/cmake/02]$ mkdir build && cd build
[brook@:~/Projects/cmake/02/build]$ cmake ../src
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- 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
-- Detecting C compile features
-- Detecting C compile features - 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
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /build/brook/Projects/cmake/02/build
[brook@:~/Projects/cmake/02/build]$ ls
CMakeCache.txt  CMakeFiles  Makefile  cmake_install.cmake  mymath01
[brook@:~/Projects/cmake/02/build]$ cmake --build .
Scanning dependencies of target MyMathLib1
[ 25%] Building C object mymath01/CMakeFiles/MyMathLib1.dir/mymath01.c.o
[ 50%] Linking C static library libMyMathLib1.a
[ 50%] Built target MyMathLib1
Scanning dependencies of target Tutorial
[ 75%] Building C object CMakeFiles/Tutorial.dir/hello.c.o
[100%] Linking C executable Tutorial
[100%] Built target Tutorial
[brook@:~/Projects/cmake/02/build]$ ls
CMakeCache.txt  CMakeFiles  Makefile  Tutorial  cmake_install.cmake  mymath01
[brook@:~/Projects/cmake/02/build]$ ./Tutorial  5
25

預設是build STATIC, 如果要改成SHARED, 只要加上SHARED這個Key word就可以了add_library(MyMathLib1 SHARED mymath01.c), 並利用set_target_properties()給shared library version與soversion.
[brook@:~/Projects/cmake/02-1]$ mkdir build && cd build
[brook@:~/Projects/cmake/02-1/build]$ cat ../src/mymath01/CMakeLists.txt
# Add a library to the project using the specified source files.
# add_library(<name> [STATIC | SHARED | MODULE]
#             [EXCLUDE_FROM_ALL]
#                       source1 [source2 ...])
add_library(MyMathLib1 SHARED mymath01.c)
set_target_properties(MyMathLib1 PROPERTIES VERSION 1.2.3 SOVERSION 1)

[brook@:~/Projects/cmake/02-1/build]$ cmake ../src
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- 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
-- Detecting C compile features
-- Detecting C compile features - 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
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /build/brook/Projects/cmake/02-1/build
[brook@:~/Projects/cmake/02-1/build]$ cmake --build .
Scanning dependencies of target MyMathLib1
[ 25%] Building C object mymath01/CMakeFiles/MyMathLib1.dir/mymath01.c.o
[ 50%] Linking C shared library libMyMathLib1.so
[ 50%] Built target MyMathLib1
Scanning dependencies of target Tutorial
[ 75%] Building C object CMakeFiles/Tutorial.dir/hello.c.o
[100%] Linking C executable Tutorial
[100%] Built target Tutorial
[brook@:~/Projects/cmake/02-1/build]$ ls -al mymath01/
total 32
drwxrwxrwx 3 brook chbg 4096 Jun 26 21:51 .
drwxrwxrwx 4 brook chbg 4096 Jun 26 21:51 ..
drwxrwxrwx 3 brook chbg 4096 Jun 26 21:51 CMakeFiles
-rw-rw-rw- 1 brook chbg 5602 Jun 26 21:50 Makefile
-rw-rw-rw- 1 brook chbg 1135 Jun 26 21:50 cmake_install.cmake
lrwxrwxrwx 1 brook chbg   18 Jun 26 21:51 libMyMathLib1.so -> libMyMathLib1.so.1
lrwxrwxrwx 1 brook chbg   22 Jun 26 21:51 libMyMathLib1.so.1 -> libMyMathLib1.so.1.2.3
-rwxrwxrwx 1 brook chbg 7440 Jun 26 21:51 libMyMathLib1.so.1.2.3





2022年6月11日 星期六

Table Of Content for "CMake Tutorial"



Step 1: A Basic Starting Point
Step 2: Adding a Library
- Step 2: Adding A Library As An Option
Step 3: Adding Usage Requirements for a Library
Step 4: Installing and Testing
Step 5: Adding System Introspection
Step 6: Adding a Custom Command and Generated File
Step 7: Packaging an Installer
Step 8: Adding Support for a Testing Dashboard
Step 9: Selecting Static or Shared Libraries
Step 10: Adding Generator Expressions
Step 11: Adding Export Configuration
Step 12: Packaging Debug and Release



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