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




張貼者： c.s. 於 清晨7:00
標籤：

2 則留言:

  1. c.s.2022年6月26日 清晨6:59

    https://unix.stackexchange.com/questions/475/how-do-so-shared-object-numbers-work

    libNAME.so is the filename used by the compiler/linker when first looking for a library specified by -lNAME. Inside a shared library file is a field called the SONAME. This field is set when the library itself is first linked into a shared object (so) by the build process. This SONAME is actually what a linker stores in an executable depending on that shared object is linked with it. Normally the SONAME is in the form of libNAME.so.MAJOR and is changed anytime the library becomes incompatible with existing executables linked to it and both major versions of the library can be kept installed as needed (though only one will be pointed to for development as libNAME.so) Also, to support easily upgrading between minor versions of a library, libNAME.so.MAJOR is normally a link to a file like libNAME.so.MAJOR.MINOR. A new minor version can be installed and once completed, the link to the old minor version is bumped to point to the new minor version immediately upgrading all new executions to use the upgraded library. Also, see my answer to Linux, GNU GCC, ld, version scripts and the ELF binary format -- How does it work?

    回覆刪除
  2. c.s.2022年6月26日 下午5:35

    https://unix.stackexchange.com/questions/475/how-do-so-shared-object-numbers-work

    Shared libraries should be versioned according to the following scheme:

    blah.so.X.Y.Z
    where

    X = backwards incompatible ABI release
    Y = backwards compatible ABI release
    Z = Internal changes only - no change to the ABI

    回覆刪除

訂閱： 張貼留言 (Atom)

熱門文章

  • [轉載]Linux中tty、pty、pts的概念區別
    轉自 http://www.wretch.cc/blog/redsonoma/14021073 基本概念： 1> tty(終端設備的統稱): tty一詞源於Teletypes，或者teletypewriters，原來指的是電傳打字機，是通過串行線用打印機鍵盤通過閱...
  • Linux Modules（7.3）- work queue
    Work queue提供一個interface，讓使用者輕易的建立kernel thread並且將work綁在這個kernel thread上面，如下圖[1]所示。 由於work queue是建立一個kernel thread來執行，所以是在process context...
  • Linux Kernel（5）- ioctl
    (V)將介紹file operations中的ioctl。ioctl的prototype為： int (*ioctl) (struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg); ...
  • word不能存檔問題
    這兩天電腦的word忽然都不能存檔，即便是另存新檔也不行，最後都只能放棄修改檔案，即便重新安裝過或者更新成2007也都不能存檔，最後就乖乖的google一下，原來是暫存的資料夾不存在，按照以下方式就可以解決了。 資料來源： word 2003不能存檔問題 編輯機碼的(reg...
  • Linux Kernel（13）- syscall
    System Call在HW和user space提供一層抽象層，主要目的有： 為user space提供硬體抽象層。比如，讀取檔案時，不用管檔案所在的媒體類型與檔案儲存類型。 System call能確保系統的安全與穩定。避免user space的無意或惡意的破壞。 ...
  • Linux Kernel（9）- Kthread
    在kernel中建立thread可以使用kthread_create()，建立一個task，然後在調用wake_up_process(task)讓task真正的運行，如果要kill一個kthread可以使用kthread_stop()。 在kernel中，將kthread_cr...
  • Linux Kernel（1）- Linux Module簡介
    Linux module練習手札I紀錄如何撰寫一個簡單的module，並且編輯它，以及load和unload一個module。 write a module #include <linux/init.h> #include <linux/module.h...
  • nc — arbitrary TCP and UDP connections and listens
    幾乎任何使用 TCP，UDP或UNIX-domain socket的動作都可以用nc來達成，常見的功能如。 simple TCP proxies shell-script based HTTP clients and servers network daemon testi...
  • Linux Kernel（15）- Platform Devices
    很多人心中都有過一個問題 What is the difference between Platform driver and normal device driver? ，簡單的來說Platform devices就non-discoverable，也就是device本身沒辦法...
  • extjs - Ext.grid.GridPanel簡介
    組成元件 要能正確顯示資料，必須包含資料倉儲(Store)，資料欄位的定義(ColumnModel)。 首先我們先定義資料欄位： var cm = new Ext.grid.ColumnModel({ {header: 'Name', dataIndex...