Re: System includes

[Wayne Scott]

From: address@hidden
> I've been trying cons again (the latest version of ActivePerl 
> contains Digest::MD5 by default, so I can finally use cons on 
> Windows at work) and I hit trouble: for the purpose of 
> dependency analysis, cons doesn't consider "system" includes 

I haven't been using the latest cons, but earlier versions
always handled angle bracket includes.

Look at this function from the package scan::cpp.

# Scan the specified file for include lines.
sub scan {
    my($self, $file) = @_;
    my($angles, $quotes);

    if (exists $file->{angles}) {
        $angles = $file->{angles};
        $quotes = $file->{quotes};
    } else {
        my(@anglenames, @quotenames);
        return () unless open(SCAN, $file->rpath);
        while (<SCAN>) {
            next unless /^\s*#/;
            if (/^\s*#\s*include\s*([<"])(.*?)[>"]/) {
                if ($1 eq "<") {
                    push(@anglenames, $2);
                } else {
                    push(@quotenames, $2);
                }
            }
        }
        close(SCAN);
        $angles = $file->{angles} = address@hidden;
        $quotes = $file->{quotes} = address@hidden;
    }


    my(@shortpath) = @{$self->{path}};    # path for <> style includes
    my(@longpath) = ($file->{dir}, @shortpath); # path for "" style includes

    my(@includes);

    for $name (@$angles) {
        for $dir (@shortpath) {
            my($include) = $dir->lookup_accessible($name);
            if ($include) {
                push(@includes, $include) unless $include->ignore;
                last;
            }
        }
    }

    for $name (@$quotes) {
        for $dir(@longpath) {
            my($include) = $dir->lookup_accessible($name);
            if ($include) {
                push(@includes, $include) unless $include->ignore;
                last;
            }
        }
    }

    return @includes
}


It includes both types of includes and understands how the search
paths are different for the two.  Now one thing about this scanner, it
can't be sure every #include it finds is real. It doesn't do a full
CPP parse.  So if the file is not found when it is searched, then it
is ignored.

Ah!  I see the problem.  cons doesn't include any search directories
by default.  So when it finds:
   #include <stdio.h>

It will be ignored because it doesn't know to look in /usr/include to
find it.  (unix right?)

So add /usr/include to your CPPPATH in the enviroment and things will
start working.  It will pass an extra -I/usr/include to the compile,
but that shouldn't hurt anything. 

Does that help?

-Wayne