From: Joe Van Dyk <joevandyk@...>
Date: 2005-07-16T05:24:42+09:00
Subject: Re: rake question

On 7/15/05, Joe Van Dyk <joevandyk@gmail.com> wrote:
> On 7/15/05, Olaf Klischat <klischat@cs.tu-berlin.de> wrote:
> > Joe Van Dyk <joevandyk@gmail.com> writes:
> >
> > > On 7/14/05, Joe Van Dyk <joevandyk@gmail.com> wrote:
> > >> 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?
> > >
> > > 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.
> >
> > Well, AFAICS it happens to be the case that, when you have defined an
> > explicit task like foo.cpp, then rules matching the task name won't be
> > considered when computing the dependencies of the task. See Task.[] in
> > rake.rb for details -- given a task name, it just returns the task if
> > it is defined, without considering additional dependencies imposed by
> > rules matching the task's name.
> >
> > This could be considered unfortunate behaviour or a bug :) A related
> > problem I had is that rules can only define a single prerequisite,
> > which seems like a quite arbitrary restriction to me.
> 
> Hm.  So, are there any work arounds, other than to rebuild the entire
> thing when a .h file changes?
> 
> What I'm trying to do is become a better software developer.  So, I've
> got a couple C and C++ books.  I want to do the examples in them.  So
> I'll have directories like
> /
> /c/
> /c/problem_1_1/
> /c/problem_1_2/
> /c/problem_1_2/main.c
> /c/problem_1_2/foo.c
> /c/problem_1_2/foo.h
> /c/problem_1_2/test_foo.c
> /c++/
> 
> 
> And so on.  I want a Rake file that will go into the directory
> structure, compile all the code, compile all the test code, and run
> the tests.  Then I want it to create syntax-highlighted webpages that
> shows for each example the code and the output and the tests, and then
> posts them to a website where I can get comments on them.
> 
> Perhaps I'll have separate build directories (so I can build and test
> the code on Windows, Linux, FreeBSD, and OS X)..
> 
> So, I'm looking for help for that.

And I haven't looked at Rant much, would it be better for my purposes?
 Rake and Rant are both general purpose build utilities, right?