dag

Make 和 DAG 的关系

Posted on by 逸飞

Make 实际上包含两部分，一部分是一个任务之间的依赖的逻辑关系（DAG)，另一部分是对 C 语言本身的一些实现知识，比如说 o 文件依赖 c 文件这些。

基本规则

Makefile 是一个 DSL，它的基础语法很简单：

目标：依赖
    从依赖生成目标的命令

Basic usage

In most projects, we have a .h file for functiont interfaces, and the whole program depends on it. Typically, all .o files are compiled from corresponding .c source files

cc = gcc              # marco
prom = calc
deps = calc.h         # the one .h to rule them all
obj = main.o getch.o getop.o stack.o
$(prom): $(obj)
    $(CC) -o $(prom) $(obj)
%.o: %.c $(deps)      # pattern rule, which means all .o depends on all .c and $(deps)
    $(CC) -c $< -o $@ # $< means the depender and $@ means the dependee

如何传递参数

run: ./prog
    ./prog $(ARGS)

make run ARGS="asdf"

Functions

we can make the file even smarter by using makefile funcions
Makefile function syntax $(func params)

cc = gcc
prom = calc
deps = $(shell find ./ -name "*.h") # find all header files using the builtin shell function
src = $(shell find ./ -name "*.c")
obj = $(src:%.c=%.o)
$(prom): $(obj)
    $(CC) -o $(prom) $(obj)
%.o: %.c $(deps)
    $(CC) -c $< -o $@
clean: # 没有依赖的命令
    rm -rf $(obj) $(prom)

如何执行多个命令

在 Python 中，我们就需要进入到

Autotools

Autotools is a collection of three tools:

  1. autoconf — This is used to generate the “configure” shell script. As I mentioned earlier, this is the script that analyzes your system at compile-time. For example, does your system use “cc” or “gcc” as the C compiler?
  2. automake — This is used to generate Makefiles. It uses information provided by Autoconf. For example, if your system has “gcc”, it will use “gcc” in the Makefile. Or, if it finds “cc” instead, will use “cc” in the Makefile.
  3. libtool — This is used to create shared libraries, platform-independently.
$ autoscan                    #--> creates &#x60;autoscan.scan&#x60; file
$ mv autoscan.scan to &#x60;autoscan.ac&#x60; file
$ autoconf                    # --> use autoconf.ac to create &#x60;configure&#x60; file
# we need a &#x60;makefile.in&#x60; as the template for configure file to use
$ automake                    # --> use &#x60;makefile.in&#x60; to create &#x60;makefile&#x60;
$ autoheader                  # --> generate &#x60;config.h.in&#x60;
$ ./configure                 # --> generate the makefile and config.h
$ make &amp;&amp; make install        # horry!

To be continued at:
http://markuskimius.wikidot.com/programming:tut:autotools:5

premake 基本用法

premake 可以生成 makefile
premake gmake
生成的 makefile 支持
make 默认构建
make help 查看帮助文件
make config=release 按照 release 构建
make clean 清除构建
make config=release clean 清除 release 构建

premake5 脚本的名字是 premake5.lua, 本质上就是一个 lua 脚本，每一行都是一个函数调用，因为参数恰好是字符串或者 table, 所以可以省略括号

-- premake5.lua
workspace "HelloWorld"
   configurations { "Debug", "Release" }
project "HelloWorld"
   kind "ConsoleApp"
   language "C"
   targetdir "bin/%{cfg.buildcfg}"
files { "**.h", "**.c" }
filter "configurations:Debug"
      defines { "DEBUG" }
      flags { "Symbols" }
filter "configurations:Release"
      defines { "NDEBUG" }
      optimize "On"

常用函数

workspace   相当于 vs 的 solution
project project
kind     指定编译目标类型   ConsoleApp WindowedApp    SharedLib StaticLib
location     指定编译目标目录
define   定义常量
files   添加文件    文件名 *.ext **.ext
removefiles  屏蔽文件
links   链接库
libdirs 添加库目录
configurations  指定不同的编译选项   需要通过 filter {"configurations:<name>"} 指定具体选项
platforms    指定不同的平台    和 vs 的 platform 类似，但是也需要使用 filter 定义
includedirs 添加 include 目录
optimize     设置优化选项  Off On
buildoptions    编译选项    比如 -std=c99

作用范围

作用范围会发生继承，使用 workspce '*' 或者 project '*'代表选中了所有 workspace 或者 project

premake install

newaction {
   trigger     = "install",
   description = "Install the software",
   execute = function ()
      -- copy files, etc. here
   end
}

参考

  1. https://stackoverflow.com/questions/2367284/how-does-the-make-j-option-actually-work
  2. http://www.epubit.com.cn/article/546
  3. https://stackoverflow.com/questions/2214575/passing-arguments-to-make-run