From: Stefan Lang <langstefan@...>
Date: 2005-07-15T21:20:17+09:00
Subject: Re: rake question

On Friday 15 July 2005 09:06, Joe Van Dyk wrote:
> On 7/14/05, Joe Van Dyk <joevandyk@gmail.com> wrote:
[...]
> > Example:
> >
> > PowerBook:~/that_stuff/test1 joe$ ls
> > Rakefile                another_test.h          test.cpp
> > another_test.cpp        main.cpp                test.h
> >
> > PowerBook:~/that_stuff/test1 joe$ cat Rakefile
> > require 'rake/clean'
> > CLEAN.include '*.o', 'test'
> > CPP_SOURCE = FileList['*.cpp']
> > OBJS = CPP_SOURCE.ext 'o'
> >
> > task :default => :run
> > task :run => "test" do
> >   sh "./test"
> > end
> > file "test" => OBJS do
> >   sh "g++ -o test #{OBJS}"
> > end
> > rule '.o' => '.cpp' do |t|
> >   sh "g++ -c -o #{t.name} #{t.source}"
> > end
> > CPP_SOURCE.each do |cpp|
> >   headers = File.read(cpp).scan(/^#include "(.+)"/)
> >   task cpp => headers
> > end
> >
> > PowerBook:~/that_stuff/test1 joe$ rake
> > (in /Users/joe/that_stuff/test1)
> > g++ -c -o another_test.o another_test.cpp
> > g++ -c -o main.o main.cpp
> > g++ -c -o test.o test.cpp
> > g++ -o test another_test.o main.o test.o
> > ./test
> > Whassup
> > what's up!
> >
> >
> > PowerBook:~/that_stuff/test1 joe$ touch main.cpp
> > PowerBook:~/that_stuff/test1 joe$ rake
> > (in /Users/joe/that_stuff/test1)
> > ./test
> > Whassup
> > what's up!
> >
> > It should've recompiled main.cpp and relinked everything, right?
>
> When I comment out
>
> > CPP_SOURCE.each do |cpp|
> >   headers = File.read(cpp).scan(/^#include "(.+)"/)
> >   task cpp => headers
> > end
>
> Then it works as expected.  So, "task cpp => headers" is the culprit.
> But I'm still not sure why it breaks everything else.

Your logic should be correct. It works if i run it with Rant (with some
minor Rake->Rant translations). Don't know why it doesn't work with Rake.

I don't want to advertise but Rant can scan #includes for you:

import "c/dependencies", "autoclean"
CPP_SOURCE = sys['*.cpp']
OBJS = CPP_SOURCE.map { |f| f.sub_ext "o" }

task :run => "test" do
  sys "./test"
end
gen C::Dependencies
gen Action do source "c_dependencies" end
file "test" => OBJS do
  sys "g++ -o test #{OBJS.arglist}"
end
gen Rule, '.o' => '.cpp' do |t|
  sys "g++ -c -o #{t.name} #{t.source}"
end
desc "Remove generated files."
gen AutoClean

-- 
Stefan