build.pl: basic Perl-based buildsystem

1 files changed, 138 insertions, 0 deletions

diff --git a/build.pl b/build.pl
new file mode 100755
index 0000000..7662e05
--- /dev/null
+++ b/build.pl
@@ -0,0 +1,138 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use autodie;
+use feature qw(say);
+use constant {
+    CC      => $ENV{CC} // 'gcc',
+    CFLAGS  => $ENV{CFLAGS},
+    LDFLAGS => $ENV{LDFLAGS},
+    LIBS    => $ENV{LIBS},
+    DESTDIR => $ENV{DESTDIR},
+};
+
+use Cwd;
+use Getopt::Long;
+
+my $DRYRUN = 0;
+my $BUILDROOT = getcwd . '/build';
+
+sub _scan_src {
+    my ($path) = @_;
+
+    my %project = ();
+
+    # directory possibly containing projects
+    opendir(my $d, $path);
+    for my $ent (readdir $d) {
+        next if ($ent =~ /^\./);
+        if (-d "$path/$ent") {
+            $project{$ent} = {};
+            my @outputs = ();
+            my @files = ();
+
+            # this is a project
+            opendir(my $dh, "$path/$ent");
+            for my $subent (readdir $dh) {
+                next unless (-e "$path/$ent/$subent");
+                if ($subent =~ /\.c$/) {
+                    push @files, $subent;
+                } elsif ($subent =~ /\.\d$/) {
+                    my @frags = split /\./, $subent, 2;
+                    push @outputs, $frags[0];
+                }
+            }
+
+            $project{$ent}{outputs} = \@outputs;
+            $project{$ent}{files} = \@files;
+        }
+    }
+
+    return \%project;
+}
+
+sub build {
+    my %bin = %{ _scan_src "bin" };
+    my %ubin = %{ _scan_src "usr.bin" };
+
+    unless (-d $BUILDROOT) {
+        system('mkdir', '-p', $BUILDROOT) == 0 or die "Couldn't create buildroot: $?\n";
+    }
+
+    for my $project (keys %bin) {
+        build_project('bin', $project, $bin{$project}{outputs}, $bin{$project}{files});
+    }
+    for my $project (keys %ubin) {
+        build_project('usr.bin', $project, $ubin{$project}{outputs}, $ubin{$project}{files});
+    }
+}
+
+sub build_project {
+    my ($path, $project, $outputs, $files) = @_;
+    my @outputs = @{ $outputs };
+    my @files   = @{ $files };
+    my (@cflags, @ldflags, @libs);
+    if (defined(CFLAGS))  { @cflags  = split(' ', CFLAGS);  } else { @cflags  = (); }
+    if (defined(LDFLAGS)) { @ldflags = split(' ', LDFLAGS); } else { @ldflags = (); }
+    if (defined(LIBS))    { @libs    = split(' ', LIBS);    } else { @libs    = (); }
+
+    chdir "$path/$project";
+    for my $target (@outputs) {
+        my @args = ('-o', "$BUILDROOT/$target");
+        push @args, @cflags, @ldflags, @libs, @files;
+        if ($DRYRUN) {
+            say 'Would exec ' . CC . ' ' . join ' ', @args;
+        } else {
+            system(CC, @args) == 0 or die "Failed to compile $project/$target: $?\n";
+        }
+    }
+    chdir "../..";
+}
+
+sub install {
+    my %bin = %{ _scan_src "bin" };
+    my %ubin = %{ _scan_src "usr.bin" };
+
+    for my $project (keys %bin) {
+        install_project('bin', $project, $bin{$project}{outputs});
+    }
+    for my $project (keys %ubin) {
+        install_project('usr/bin', $project, $ubin{$project}{files});
+    }
+}
+
+sub install_project {
+    my ($path, $project, @outputs) = @_;
+
+    system 'mkdir', '-p', DESTDIR . "/$path" == 0 or die "Failed to create target path: $?\n";
+    for my $target (@outputs) {
+        my @args = ('-Dm755', "$BUILDROOT/$target", DESTDIR . "/$path/$target");
+        if ($DRYRUN) {
+            say 'Would exec install ' . join ' ', @args;
+        } else {
+            system('install', @args) == 0 or die "Failed to install $target: $?";
+        }
+    }
+}
+
+my %modes = (
+    'build'   => \&build,
+    'install' => \&install,
+);
+
+sub main {
+    GetOptions(
+        'buildroot=s'   => \$BUILDROOT,
+        'dry-run'       => \$DRYRUN,
+    ) or die "Unrecognied commandline options.\n";
+    my $mode = 'build';
+
+    if (@ARGV > 0) {
+        $mode = $ARGV[0];
+    }
+    say $mode . 'ing...';
+    $modes{$mode}->();
+}
+
+main;