From: Joe Van Dyk <joevandyk@...>
Date: 2005-07-15T15:56:04+09:00
Subject: rake question

rule '.o' => ['.c'] do |t|
    sh "cc #{t.source} -c -o #{t.name}"
end

But, when I change the .c source file, it doesn't get compiled again. 
Why is that?

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?