[Linux] [C / C ++] Notes about Waf build system

Caution

This document is confirmed by waf-1.9.3. Please cross-check with Original Document as there may be changes.

Overview

Summary about Waf, a build tool made by python

Waf defines a file called wscript and builds it.

Since the Japanese materials are solid, I think you should basically refer to the following pages. (Because it is translated by volunteers, isn't it the latest? * Confirmation required) The Waf Book

The original English materials are as follows. The Waf Book

merit and demerit

merit

• Can you write in python?

Demerit

• Is it slower than CMake? (The story of its predecessor SCons?) * Confirmation required
• A little knowledge of Python seems to be required (CMake is also a unique language, so which one?)

Preparation

Download Waf

Download the source from Official Site or Github.

Download executable binary directly

$ wget --no-check-certificate https://waf.io/waf-1.9.3 -O waf

Build from source

$ git clone https://github.com/waf-project/waf.git
$ cd waf
$ ./waf-light configure build
$ ls
build  build_system_kit  ChangeLog  configure  demos  DEVEL  docs  playground  README.md  tests  TODO  utils  waf  waflib  waf-light  wscript  zip

Check the sample for the time being

If you built from source, there is a demo in the repository. There are samples in various languages, so you can refer to them.

C language sample build test

$ cd demos
$ ls
asm  bisonflex  c  c++  csharp  d  dbus  fortran  glib2  intltool  java  jni  lua  mac_app  perl  precious  python  qt5  ruby  subst  tex  unit_test  vala  variants  wscript
$ cd c
$ ../../waf configure build
Setting top to                           : /home/user/work/waf/demos/c
Setting out to                           : /home/user/work/waf/demos/c/build
Checking for 'gcc' (C compiler)          : /usr/bin/gcc
Checking for code snippet                : yes
Checking for code snippet                : yes
Checking for code snippet                : yes
Checking for libraries                   : yes
Checking for library m                   : yes
Checking for large file support          : yes
Checking for inline                      : inline
Checking for endianness                  : little
Checking for headers in parallel         : started
... testing an arbitrary build function  : ok
... stdio                                : yes
... unistd                               : yes
... optional xyztabcd.h                  : no
... stdlib                               : aye
... malloc                               : yes
-> processing test results               : 1 test failed
Checking for header stdio.h              : yes
Checking for code snippet                : yes
'configure' finished successfully (1.405s)
Waf: Entering directory `/home/user/work/waf/demos/c/build'
[ 1/16] Creating build/program/b.h
[ 2/16] Creating build/abc.h
[ 3/16] Creating build/stlib/foo.h
[ 4/16] Processing wscript
[ 5/16] Trying again wscript
-Lm -Lncurses -L../wscript ayedoh -Laaa -L/home/user/work/waf/demos/c/wscript

-Lm -Lncurses -L../wscript ayedoh -Laaa -L/home/user/work/waf/demos/c/wscript

[ 6/16] Compiling stlib/main.c
[ 7/16] Compiling program/main.c
[ 8/16] Compiling shlib/test_shlib.c
[ 9/16] Compiling shlib/main.c
[10/16] Compiling stlib/test_staticlib.c
[11/16] Linking build/program/myprogram
[12/16] Linking build/shlib/libmy_shared_lib.so
[13/16] Linking build/stlib/libmy_static_lib.a
[14/16] Linking build/shlib/test_shared_link
[15/16] Linking build/stlib/test_static_link
[16/16] Symlinking build/shlib/libmy_shared_lib.so
Waf: Leaving directory `/home/user/work/waf/demos/c/build'
'build' finished successfully (1.162s)

wscript implementation procedure

wscript basics

waf defines the functions in wscript as * waf commands *. As an example, the waf command hello is defined below.

sample

#! /usr/bin/env python
# encoding: utf-8

def hello(ctx):
    print('hello world')

Execute waf command hello

$ ./waf hello
hello world
'hello' finished successfully (0.001s)

By specifying hello as the execution command of waf, you can see that the command is being executed.

Build a C ++ project

See below in the original document The Waf Book

main.cpp

#include <iostream>

int main(int argc, char const* argv[])
{
    std::cout << "hoge" << std::endl;
    return 0;
}

C++Build the project

#! /usr/bin/env python
# encoding: utf-8

def options(opt):
    opt.load('compiler_cxx')

def configure(conf):
    conf.load('compiler_cxx')

def build(bld):
    bld.program(source='main.cpp', target='app')

Build and execution results

$ ./waf configure build
Setting top to                           : /home/user/work/test
Setting out to                           : /home/user/work/test/build
Checking for 'g++' (C++ compiler)        : /usr/bin/g++
'configure' finished successfully (0.051s)
Waf: Entering directory `/home/user/work/test/build'
Waf: Leaving directory `/home/user/work/test/build'
'build' finished successfully (0.003s)
$ ./build/app
hoge

For other details (include, build shared library, etc.), please refer to the original document. The Waf Book

TODO: Add if you have time

Cross-build environment support

It seems that cross-build can be supported by changing the environment variable.

The Waf Book Re: [waf-users 4515] Cross-compiling QNX using qcc --Google Groups

reference

Waf: the meta build system Introduction of waf --Mackey's Lab

The following is Japanese material, but please note that the content is out of date (2010 & 2011 article) The Waf Book waf tutorial --Pure functional miscellaneous notes