Build system: add include directories and dependencies for generators

In the case of generating a file like this:

    GENERATE[foo.S]=mkfoo.pl arg1 arg2

the 'mkfoo.pl' generator itself might need to include other files,
such as perl modules within our source tree.  We can reuse already
existing syntax for it, like this:

    INCLUDE[mkfoo.pl]=module/path

or:

    DEPEND[mkfoo.pl]=modules/mymodule.pm

This change implements the support for such constructs, and for the
DEPEND statement, for any value that indicates a perl module (.pm
file), it will automatically infer an INCLUDE statement for its
directory, just like it does for C header files, so you won't have do
write this:

    DEPEND[mkfoo.pl]=modules/mymodule.pm
    INCLUDE[mkfoo.pl]=modules

Reviewed-by: Emilia Käsper <emilia@openssl.org>

Configurations/common.tmpl

diff --git a/Configurations/common.tmpl b/Configurations/common.tmpl
index cdcaf53..af1746a 100644
--- a/Configurations/common.tmpl
+++ b/Configurations/common.tmpl
@@ -42,8 +42,11 @@
      my $bin = shift;
      my %opts = @_;
      if ($unified_info{generate}->{$src}) {
+         my $script = $unified_info{generate}->{$src}->[0];
          $OUT .= generatesrc(src => $src,
                              generator => $unified_info{generate}->{$src},
+                             generator_incs => $unified_info{includes}->{$script},
+                             generator_deps => $unified_info{depends}->{$script},
                              deps => $unified_info{depends}->{$src},
                              incs => [ @{$unified_info{includes}->{$bin}},
                                        @{$unified_info{includes}->{$obj}} ],

Configurations/descrip.mms.tmpl

diff --git a/Configurations/descrip.mms.tmpl b/Configurations/descrip.mms.tmpl
index 2e58b1a..416f0ed 100644
--- a/Configurations/descrip.mms.tmpl
+++ b/Configurations/descrip.mms.tmpl
@@ -441,12 +441,13 @@
   sub generatesrc {
       my %args = @_;
       my $generator = join(" ", @{$args{generator}});
-      my $deps = join(", -\n\t\t", @{$args{deps}});
+      my $generator_incs = join("", map { ' "-I'.$_.'"' } @{$args{generator_incs}});
+      my $deps = join(", -\n\t\t", @{$args{generator_deps}}, @{$args{deps}});
 
       if ($args{src} !~ /\.[sS]$/) {
           return <<"EOF";
 $args{src} : $args{generator}->[0] $deps
-	\$(PERL) $generator > \$@
+	\$(PERL)$generator_incs $generator > \$@
 EOF
       } else {
           die "No method to generate assembler source present.\n";

Configurations/unix-Makefile.tmpl

diff --git a/Configurations/unix-Makefile.tmpl b/Configurations/unix-Makefile.tmpl
index 1676b71..900c09f 100644
--- a/Configurations/unix-Makefile.tmpl
+++ b/Configurations/unix-Makefile.tmpl
@@ -808,19 +808,20 @@
   sub generatesrc {
       my %args = @_;
       my $generator = join(" ", @{$args{generator}});
+      my $generator_incs = join("", map { " -I".$_ } @{$args{generator_incs}});
       my $incs = join("", map { " -I".$_ } @{$args{incs}});
-      my $deps = join(" ", @{$args{deps}});
+      my $deps = join(" ", @{$args{generator_deps}}, @{$args{deps}});
 
       if ($args{src} !~ /\.[sS]$/) {
           return <<"EOF";
 $args{src}: $args{generator}->[0] $deps
-	\$(PERL) $generator > \$@
+	\$(PERL)$generator_incs $generator > \$@
 EOF
       } else {
           if ($args{generator}->[0] =~ /\.pl$/) {
-              $generator = 'CC="$(CC)" $(PERL) '.$generator;
+              $generator = 'CC="$(CC)" $(PERL)'.$generator_incs.' '.$generator;
           } elsif ($args{generator}->[0] =~ /\.m4$/) {
-              $generator = 'm4 -B 8192 '.$generator.' >'
+              $generator = 'm4 -B 8192'.$generator_incs.' '.$generator.' >'
           } elsif ($args{generator}->[0] =~ /\.S$/) {
               $generator = undef;
           } else {

Configurations/windows-makefile.tmpl

diff --git a/Configurations/windows-makefile.tmpl b/Configurations/windows-makefile.tmpl
index c3233ee..159d57c 100644
--- a/Configurations/windows-makefile.tmpl
+++ b/Configurations/windows-makefile.tmpl
@@ -252,17 +252,18 @@
       my %args = @_;
       (my $target = $args{src}) =~ s/\.[sS]$/.asm/;
       my $generator = join(" ", @{$args{generator}});
+      my $generator_incs = join("", map { " -I".$_ } @{$args{generator_incs}});
       my $incs = join("", map { " /I ".$_ } @{$args{incs}});
-      my $deps = join(" ", @{$args{deps}});
+      my $deps = join(" ", @{$args{generator_deps}}, @{$args{deps}});
 
       if ($target !~ /\.asm$/) {
           return <<"EOF";
 $target: $args{generator}->[0] $deps
-	\$(PERL) $generator > \$@
+	\$(PERL)$generator_incs $generator > \$@
 EOF
       } else {
           if ($args{generator}->[0] =~ /\.pl$/) {
-              $generator = '$(PERL) '.$generator;
+              $generator = '$(PERL)'.$generator_incs.' '.$generator;
           } elsif ($args{generator}->[0] =~ /\.S$/) {
               $generator = undef;
           } else {