Cmake

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Cmake

Cmake

环境

WSL+cmake3.16.3

教程

CMake Tutorial — CMake 3.28.0-rc2 Documentation

Step1

cmake_minimum_required

任何项目的 CMakeLists.txt 文件都必须首先使用 cmake_minimum_required()命令指定 CMake 的最小版本。这将建立策略设置，并确保以下 CMake 功能在兼容的 CMake 版本下运行。

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cmake_minimum_required(VERSION <min>[...<policy_max>] [FATAL_ERROR])

cmake_minimum_required(VERSION 3.10)

project

要启动一个项目，我们需要使用 project() 命令来设置项目名称。每个项目都需要调用该命令，并且应在 cmake_minimum_required() 之后尽快调用。

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project(<PROJECT-NAME> [<language-name>...])

project(Tutorial)
project(Tutorial VERSION 1.0)

add_executable

告诉 CMake 使用指定的源代码文件创建可执行文件。

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add_executable(<name> [WIN32] [MACOSX_BUNDLE]
                [EXCLUDE_FROM_ALL]
                [source1] [source2 ...])
                
add_executable(Tutorial tutorial.cxx)

编译

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mkdir Step1_build
cd Step1_build
cmake ../Step1
cmake --build .

CMAKE_CXX_STANDARD

CMAKE_CXX_STANDARD_REQUIRED

CMAKE_CXX_STANDARD_REQUIRED — CMake 3.28.0-rc2 Documentation

设置以下变量来增添对C++11的支持。

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set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)

configure_file

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configure_file(TutorialConfig.h.in TutorialConfig.h)

将.in文件写入.h里面。

这个.h会生成在最后的build文件夹内，即PROJECT_BINARY_DIR（注意和PROJECT_SOURCE_DIR作出区分）

在这里面可以设置版本，当导入到头文件后也能在项目里面打印了。

target_include_directories

我们使用 target_include_directories() 来指定目标可执行文件应在何处查找包含文件。

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target_include_directories(Tutorial PUBLIC
                           "${PROJECT_BINARY_DIR}"
                           )

因为TutorialConfig.h会生成在build主文件夹下，所以只要把主目录include即可，通过PROJECT_BINARY_DIR变量。

TutorialConfig.h.in

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// the configured options and settings for Tutorial
#define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
#define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@

@<proj_name>_VERSION_MAJOR@这样的变量会在cmake的时候首先被cmake的设置进行替换（在project函数里面指定了版本），然后再将整个文件复制进TutorialConfig.h.in里面。

然后在cpp文件里面include：

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#include "TutorialConfig.h"

就可以打印这两个变量了。

总结

Step1教了以下事情：

  • 初始化一个项目，项目名及版本
  • 编译单文件成可执行文件
  • 增加对C++11的支持
  • 生成并包括头文件，从而能在源码内打印版本号

Step2

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├── CMakeLists.txt
├── MathFunctions
│   ├── CMakeLists.txt
│   ├── MathFunctions.cxx
│   ├── MathFunctions.h
│   ├── mysqrt.cxx
│   └── mysqrt.h
├── TutorialConfig.h.in
└── tutorial.cxx

目标是在主项目中编译生成并使用一个叫做MathFunctions的库。

add_library

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add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)

首先在MathFunctions里的CMakeLists.txt进行配置。

add_subdirectory

然后在主项目里面添加子项目。

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add_subdirectory(MathFunctions)
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target_link_libraries(Tutorial PUBLIC MathFunctions)

将lib连接到主项目上。

target_include_directories

修改这个来添加路径，使得cmake能找到MathFunctions的头文件。

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target_include_directories(Tutorial PUBLIC
                           "${PROJECT_BINARY_DIR}"
                           "${PROJECT_SOURCE_DIR}/MathFunctions"
                           )

PROJECT_BINARY_DIR和PROJECT_SOURCE_DIR注意作出区分

option

在MathFunctions里面添加：

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option(USE_MYMATH "Use self-defined math implementation" ON)

if

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if(<condition>)
	<commands>
elseif(<condition>) # optional block, can be repeated
	<commands>
else()              # optional block
	<commands>
endif()

比如：

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if(USE_MYMATH)
    target_compile_definitions(MathFunctions
        PRIVATE USE_MYMATH)

target_compile_definitions

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Add compile definitions to a target.

 target_compile_definitions(<target>
   <INTERFACE|PUBLIC|PRIVATE> [items1...]
   [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

target直接是整个子项目/主项目，不需要加文件后缀。

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target_compile_definitions(MathFunctions
        PRIVATE USE_MYMATH)

修改MathFunctions.cxx

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#include "MathFunctions.h"

// TODO 11: include cmath
#include <cmath>
// TODO 10: Wrap the mysqrt include in a precompiled ifdef based on USE_MYMATH
#ifdef USE_MYMATH
#  include "mysqrt.h"
#endif

namespace mathfunctions {
double sqrt(double x)
{
  // TODO 9: If USE_MYMATH is defined, use detail::mysqrt.
  #ifdef USE_MYMATH
    return detail::mysqrt(x);
  #else
    return std::sqrt(x);
  #endif
  // Otherwise, use std::sqrt.
  // return detail::mysqrt(x);
}
}

现在添加了基于USE_MYMATH宏的逻辑。

优化编译逻辑

即使USE_MYMATH被设置成OFF，上面的代码还是会编译mysqrt。

为了进行优化，一种方法是将mysqrt当作一个独立的库，然后在需要的时候再链接到MathFunctions库上。

在if块中：

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add_library(SqrtLibrary STATIC
              mysqrt.cxx
              )
              
target_link_libraries(MathFunctions PRIVATE SqrtLibrary)

然后删除

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add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)

改成：

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add_library(MathFunctions MathFunctions.cxx)

编译

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cmake ../Step2 -DUSE_MYMATH=OFF

总结

  • 编译库
  • if，option
  • 将compile flag传入源码中作为宏变量

Step3

简化文件包含

[Step 3: Adding Usage Requirements for a Library — CMake 3.28.0-rc3 Documentation](https://cmake.org/cmake/help/latest/guide/tutorial/Adding Usage Requirements for a Library.html)

在子项目中添加如下的INTERFACE代码，能够省去在主项目中明确包括子项目文件的麻烦。Cmake会自动通过INTERFACE接口来寻找到子项目文件。

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target_include_directories(MathFunctions
                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
                           )

这种情况下，只要

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target_link_libraries(Tutorial PUBLIC MathFunctions)

即可。

设置C++标准

用INTERFACE来为每个项目设置C++标准。

先删除

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set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)

然后

在主项目中添加一个INTERFACE library：（一个抽象的接口库，这个库只用于设置编译器标准等其他配置）

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add_library(tutorial_compiler_flags INTERFACE)
target_compile_features(tutorial_compiler_flags INTERFACE cxx_std_11)

然后在每一个子项目的CMakeLists.txt中添加：（只要子项目需要C++特性就要加）

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target_link_libraries(Tutorial PUBLIC MathFunctions tutorial_compiler_flags)
target_link_libraries(SqrtLibrary PUBLIC tutorial_compiler_flags)
target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)

Step4

Generator Expressions⭐

cmake-generator-expressions(7) — CMake 3.28.0-rc3 Documentation

一个挺复杂的概念。

一个$<>包裹的一个表达式。

根据下面的代码，可以笼统理解为：$<某个条件:满足某个条件后会干啥/需要满足哪些条件>

下面就是通过这个来设置布尔变量，进而添加编译器设置。

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cmake_minimum_required(VERSION 3.15)

set(gcc_like_cxx $<COMPILE_LANG_AND_ID:ARMClang,AppleClang,Clang,GNU,LCC>)
set(msvc_cxx $<COMPILE_LANG_AND_ID:CXX,MSVC>)

target_compile_options(tutorial_compiler_flags INTERFACE
  $<${gcc_like_cxx}:$<BUILD_INTERFACE:-Wall;-Wextra;-Wshadow;-Wformat=2;-Wunused>>
  $<${msvc_cxx}:$<BUILD_INTERFACE:-W3>>
)

Step5

安装

用install函数来实现cmake install功能。

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set(installable_libs MathFunctions tutorial_compiler_flags)
if(TARGET SqrtLibrary)
  list(APPEND installable_libs SqrtLibrary)
endif()
install(TARGETS ${installable_libs} DESTINATION lib)

install(FILES MathFunctions.h DESTINATION include)
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install(TARGETS Tutorial DESTINATION bin)

install(FILES ${PROJECT_BINARY_DIR}/TutorialConfig.h DESTINATION include)

总结一下：

  1. ${}是用来将变量解析的，转化成变量所表示的值。否则这个变量就当成一个字符串来看了。
  2. install中TARGETS用于指向每个项目（表示其生成的可执行文件），FILES表示一般文件（这里用于头文件），默认路径是源码路径（PROJECT_SOURCE_DIR）；DESTINATION表示安装的文件夹
  3. list APPEND用于为变量（实际上是一个列表）添加元素
  4. if TARGET意思是如果生成了SqrtLibrary这个可执行文件，则

最后执行命令

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cmake --install . --prefix "path/to/installDir"

测试

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# TODO 5: Enable testing
enable_testing()
# TODO 6: Add a test called Runs which runs the following command:
# $ Tutorial 25
add_test(NAME Runs COMMAND Tutorial 25)
# TODO 7: Add a test called Usage which runs the following command:
# $ Tutorial
# Make sure the expected output is displayed.
# Hint: Use the PASS_REGULAR_EXPRESSION property with "Usage.*number"
add_test(NAME Usage COMMAND Tutorial)
set_tests_properties(Usage
  PROPERTIES PASS_REGULAR_EXPRESSION "Usage.*number"
)
# TODO 8: Add a test which runs the following command:
# $ Tutorial 4
# Make sure the result is correct.
# Hint: Use the PASS_REGULAR_EXPRESSION property with "4 is 2"
add_test(NAME StandardUse COMMAND Tutorial 4)
set_tests_properties(StandardUse
PROPERTIES PASS_REGULAR_EXPRESSION "4 is 2")
# TODO 9: Add more tests. Create a function called do_test to avoid copy +
# paste. Test the following values: 4, 9, 5, 7, 25, -25 and 0.0001.
function(do_test target arg result)
  add_test(NAME Comp${arg} COMMAND ${target} ${arg})
  set_tests_properties(Comp${arg}
    PROPERTIES PASS_REGULAR_EXPRESSION ${result}
    )
endfunction()

# do a bunch of result based tests
do_test(Tutorial 4 "4 is 2")
do_test(Tutorial 9 "9 is 3")
do_test(Tutorial 5 "5 is 2.236")
do_test(Tutorial 7 "7 is 2.645")
do_test(Tutorial 25 "25 is 5")
do_test(Tutorial -25 "-25 is (-nan|nan|0)")
do_test(Tutorial 0.0001 "0.0001 is 0.01")

重新cmake编译

然后

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ctest -N 
ctest -VV

对于多种配置的生成器（比如VisualStudio），需要指定build：

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ctest -C Debug -VV

Step6

跳过

Step7

检查依赖完整性

这里通过检查log和exp函数是否存在作为例子。

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include(CheckCXXSourceCompiles)

check_cxx_source_compiles("
    #include <cmath>
    int main() {
      std::log(1.0);
      return 0;
    }
    " HAVE_LOG)
check_cxx_source_compiles("
    #include <cmath>
    int main() {
      std::exp(1.0);
      return 0;
    }
    " HAVE_EXP)

// 省略某些代码
  if(HAVE_LOG AND HAVE_EXP)
    target_compile_definitions(SqrtLibrary
                               PRIVATE "HAVE_LOG" "HAVE_EXP"
                               )
  endif()

  target_link_libraries(MathFunctions PRIVATE SqrtLibrary)
endif()

mymath.cxx里面：

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#include <cmath>

#if defined(HAVE_LOG) && defined(HAVE_EXP)
  double result = std::exp(std::log(x) * 0.5);
  std::cout << "Computing sqrt of " << x << " to be " << result
            << " using log and exp" << std::endl;
#else
  double result = x;

  // do ten iterations
  for (int i = 0; i < 10; ++i) {
    if (result <= 0) {
      result = 0.1;
    }
    double delta = x - (result * result);
    result = result + 0.5 * delta / result;
    std::cout << "Computing sqrt of " << x << " to be " << result << std::endl;
  }
#endif

Step8

[Step 8: Adding a Custom Command and Generated File — CMake 3.28.0-rc3 Documentation](https://cmake.org/cmake/help/latest/guide/tutorial/Adding a Custom Command and Generated File.html)

Step9

[Step 9: Packaging an Installer — CMake 3.28.0-rc3 Documentation](https://cmake.org/cmake/help/latest/guide/tutorial/Packaging an Installer.html)

Step10

[Step 10: Selecting Static or Shared Libraries — CMake 3.28.0-rc3 Documentation](https://cmake.org/cmake/help/latest/guide/tutorial/Selecting Static or Shared Libraries.html)

Step11

[Step 11: Adding Export Configuration — CMake 3.28.0-rc3 Documentation](https://cmake.org/cmake/help/latest/guide/tutorial/Adding Export Configuration.html)

Step12

[Step 12: Packaging Debug and Release — CMake 3.28.0-rc3 Documentation](https://cmake.org/cmake/help/latest/guide/tutorial/Packaging Debug and Release.html)

tag:

    缺失模块。
    1、请确保node版本大于6.2
    2、在博客根目录（注意不是yilia-plus根目录）执行以下命令：
    npm i hexo-generator-json-content --save

    3、在根目录_config.yml里添加配置： 

      jsonContent:
    meta: false
    pages: false
    posts:
      title: true
      date: true
      path: true
      text: false
      raw: false
      content: false
      slug: false
      updated: false
      comments: false
      link: false
      permalink: false
      excerpt: false
      categories: false
      tags: true

A junior undergraduate
studying in the college of cyber science and engineering
in Sichuan University
in Sichuan , China.
Pronouns:He/him.
A core member of 0x401 CTF team
majorly focus on Reverse Engineering chanllenges.