[EMAIL PROTECTED] (Dan Sugalski) writes:
> We could really use the capability of specifying per-C-file flags in
> the make procedure, something that can be built into Configure. Right
> now we build without optimizations on, which is fine, but I'd like to
> turn them on in the future.
>
> They can't be turned on unconditionally, since tsq.c *can't* have any
> optimizations turned on for it. (That's the thread-safe queue module,
> something that is annoyingly execution-order-dependent because it has
> to operate safely as interrupt code potentially interrupting itself as
> non-interrupt code) And, if Perl 5 is any guide (and I think it is)
> there will be some platform/compiler combinations that won't be able
> to compile one or more source modules with the highest optimization
> level, but will be able to manage with a lower one.
>
> So... Configure.pl needs to be able to build a makefile that has
> per-C-file flags, and those flags need to be overridable per-file at
> configure time by the platform configuration module.
I've taken this very simple approach to the problem. A perl-wrapper
for the CC lines in makefiles/root.in
.c$(O) :
$(PERL) tools/dev/cc_flags.pl $(CC) $(CFLAGS) ${cc_o_out}$@ -c $<
that takes a rules-based approach to removing or adding options to the
command-line, based on the filename of the .c-file. This gives some
overhead while building, but it keeps the complexity of the solution
down a lot.
Right now, the configure system has nothing to do with it, but it'd be
fairly simple to make it write a file like following example:
----------------------------------------------------------------------
# File: CFLAGS
# [ filename | {regex} ] -{removed option} +{added option} ...
spf_render.c -{-Wformat-nonliteral}
{^core} +{-O3}
----------------------------------------------------------------------
What're peoples opinion?
Script:
----------------------------------------------------------------------
#!/usr/bin/perl -w
use strict;
if (open F, "CFLAGS") {
my @options;
while (<F>) {
chomp;
s/#.*//;
next unless /\S/;
my $regex;
if (s/^\{(.+?)\}\s*//) {
$regex = qr/$1/;
}
elsif (s/^(\S+)\s*//) {
$regex = qr/^\Q$1\E$/;
}
else {
die "syntax error in CFLAGS: line $., $_\n";
}
while (s/^([-+])\{(.+?)\}\s*//) {
push @options, [ $regex, $1, $2 ];
}
if (/\S/) {
die "syntax error in CFLAGS: line $., $_\n";
}
}
my ($cfile) = grep /\.c$/, @ARGV;
foreach my $option (@options) {
if ($cfile =~ $option->[0]) {
if ($option->[1] eq '+') {
splice @ARGV, 1, 0, $option->[2];
}
else {
@ARGV = grep { $_ ne $option->[2] } @ARGV;
}
}
}
}
print "@ARGV\n";
exec @ARGV;
__END__
Cheers,
--
Lars Balker Rasmussen Consult::Perl
