From e287f595aa0e4eab9544bd49907d20adc9b5e977 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 5 Feb 2016 17:32:03 +0000
Subject: [PATCH] commitid.scad.pl: argument parsing, git invocation, etc.

---
 commitid.scad.pl | 158 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 157 insertions(+), 1 deletion(-)

diff --git a/commitid.scad.pl b/commitid.scad.pl
index 863e04d..b8d295a 100755
--- a/commitid.scad.pl
+++ b/commitid.scad.pl
@@ -4,7 +4,29 @@ use strict;
 $SIG{__WARN__} = sub { die @_; };
 
 #  xxx much of the comment below is TODO
-
+#
+# Usage:
+#
+#   .../commitid.scad.pl [OPTION...] [STRING...] >commitid.scad.new \
+#     && mv -f commitid.scad.new commitid.scad
+#
+# Options:
+#
+#   --git    generate git commit indications, as shown below
+#            (this is the default if no strings are requested with -t)
+#
+#   --git=object
+#            generate git commit indication based on commit object only
+#            (ie avoid counting commits)
+#
+#   -i       do not generate `+' if git-untracked files are present
+#
+#   [-t[FORM]] TEXT
+#            generate a form FORM containing TEXT
+#            TEXT can contain newlines (final newline usually undesirable)
+#            if FORM not specified, generates Arg0 Arg1 Arg2 in sequence
+#            character set is SPC 0-9 a-f + * (`*' glyph is `=/=').
+#
 # We generate a physical indication of which commit was used.
 #
 # We provide for scaling factors with dynamic variables:
@@ -41,6 +63,8 @@ $SIG{__WARN__} = sub { die @_; };
 #       padded with zeroes; if too long we reduce mod 10^n
 #       eg
 #            Tiny4    1070
+#       If tree is dirty, + or * is suffixed, reducing number of
+#       digits by 1.
 #
 #   Tiny4Q:
 #   Tiny6Q:
@@ -55,15 +79,27 @@ $SIG{__WARN__} = sub { die @_; };
 #       git-rev-parse HEAD   (prefix of requested length)
 #       eg
 #            Git6    82f2a2
+#       If tree is dirty, + or * is suffixed to commitid,
+#       reducing number of hex digits by 1.
 
+#   Small3
 #   Small4
+#   Small5
 #   Small6
+#   Small7
 #   Small8
 #       git-rev-list --first-parent --count HEAD
 #       git-rev-parse HEAD
 #       eg
 #            Small6     1070
 #                     82f2a2
+#       If tree is dirty, + or * is suffixed to count (but not to
+#       commitid) reducing number of digits by 1.
+#
+#   FontDemo
+#
+#   Arg0, Arg1, ...
+#       Strings passed on command line
 
 sub p { print @_ or die $!; }
 
@@ -188,8 +224,128 @@ sub parsefont () {
 
 parsefont();
 
+our $do_git; # contains may chars 'c' (count) and/or 'o' (object)
+our $do_git_untracked = 1;
+our $argcounter;
+
+sub rjustt ($$) { # right justify and truncate (ie, pad and truncate at left)
+    my ($sz, $whole) = @_;
+    my $lw = length $whole;
+    return $lw > $sz
+	? substr($whole, $lw-$sz)
+	: sprintf "%${sz}s", $whole;
+}
+
+sub ljustt ($$$) { # always includes $suffix
+    my ($sz, $whole, $suffix) = @_;
+    $sz -= length $suffix;
+    return sprintf "%-${sz}.${sz}s%s", $whole, $suffix;
+}
+
+sub gentextmodule_plusq ($$) {
+    my ($form, $s) = @_;
+    my $l = length $s;
+    gentextmodule($form, $s);
+    if (!($l & 1) && $l>=4) {
+	gentextmodule("${form}Q", substr($s,0,$l/2), substr($s,$l/2));
+    }
+}
+
+our @gcmd;
+
+sub gitrun_start () {
+    open F, "-|", @gcmd or die "$gcmd[0]: start: $!";
+}
+
+sub gitrun_done (;$) {
+    my ($errok) = @_;
+    $?=0; $!=0;
+    return if close F;
+    return if $errok;
+    die $! if $!;
+    die "@gcmd failed ($?)\n";
+}
+
+sub gitoutput (@) {
+    (@gcmd) = (qw(git), @_);
+    gitrun_start;
+    $_ = <F>;
+    gitrun_done;
+    defined or die "@gcmd produced no output";
+    chomp or die "@gcmd produced no final newline";
+    $_;
+}
+
+sub do_git () {
+    return unless $do_git;
+
+    @gcmd = qw(git status --porcelain);
+    push @gcmd, qw(--untracked=no) unless $do_git_untracked;
+
+    my $git_dirty = '';
+    gitrun_start;
+    while (<F>) {
+	if (m/^\?\?/ && $do_git_untracked) {
+	    $git_dirty = '+';
+	    next;
+	}
+	$git_dirty = '*';
+	last;
+    }
+    gitrun_done($git_dirty eq '*');
+
+    my $git_count;
+    my $git_object;
+
+    if ($do_git =~ m/c/) {
+	$git_count = gitoutput qw(rev-list --first-parent --count HEAD);
+    }
+    if ($do_git =~ m/o/) {
+	$git_object = gitoutput qw(rev-parse HEAD);
+    }
+
+    foreach my $sz (3..8) {
+	gentextmodule_plusq("Tiny$sz", rjustt($sz, $git_count.$git_dirty))
+	    if defined $git_count;
+
+	gentextmodule_plusq("Git$sz", ljustt($sz, $git_object, $git_dirty))
+	    if defined $git_object;
+
+	gentextmodule("Small$sz",
+		      rjustt($sz, $git_count.$git_dirty),
+		      ljustt($sz, $git_object, ''))
+	    if defined $git_count && defined $git_object;
+    }
+}    
+
+while (@ARGV) {
+    $_ = shift;
+    if (m/^--(no)?-git$/) {
+	$do_git = $1 ? '' : 'co';
+    } elsif (m/^---git=object$/) {
+	$do_git = 'o';
+    } elsif (m/^-i$/) {
+	$do_git_untracked = 0;
+    } elsif (m/^-t(.*)$/) {
+	my $form = $1;
+	die "bad usage: -t needs string argument\n";
+	$_ = shift;
+	gentextmodule($form, split /\n/, $_);
+	$argcounter //= 0;
+    } elsif (m/^[^-]/) {
+	gentextmodule("Arg$argcounter", $_);
+	$argcounter++;
+    } else {
+	die "bad usage: unknown option \`$_'\n";
+    }
+}
+
+$do_git //= defined($argcounter) ? '' : 'co';
+
 gentextmodule('FontDemo', @demo);
 
+do_git();
+
 flush STDOUT or die $!;
 close STDOUT or die $!;
 
-- 
2.30.2