userdiff/perl: catch sub with brace on second line

Accept

	sub foo
	{
	}

as an alternative to a more common style that introduces perl
functions with a brace on the first line (and likewise for BEGIN/END
blocks).  The new regex is a little hairy to avoid matching

	# forward declaration
	sub foo;

while continuing to match "sub foo($;@) {" and

	sub foo { # This routine is interesting;
		# in fact, the lines below explain how...

While at it, pay attention to Perl 5.14's "package foo {" syntax as an
alternative to the traditional "package foo;".

Requested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t4018-diff-funcname.sh b/t/t4018-diff-funcname.sh
index 8a5714912d196d0aaf681bd79363c0e6018ffaee..b2fd1a99da12916e0ea809925629d3832214cc92 100755 (executable)
--- a/t/t4018-diff-funcname.sh
+++ b/t/t4018-diff-funcname.sh
@@ -35,7 +35,11 @@ package Beer;
 use strict;
 use warnings;
 use parent qw(Exporter);
-our @EXPORT_OK = qw(round);
+our @EXPORT_OK = qw(round finalround);
+
+sub other; # forward declaration
+
+# hello
 
 sub round {
        my ($n) = @_;
@@ -46,6 +50,12 @@ sub round {
        print "$n bottles of beer on the wall.\n";
 }
 
+sub finalround
+{
+       print "Go to the store, buy some more\n";
+       print "99 bottles of beer on the wall.\n");
+}
+
 __END__
 
 =head1 NAME
@@ -54,12 +64,13 @@ Beer - subroutine to output fragment of a drinking song
 
 =head1 SYNOPSIS
 
-       use Beer qw(round);
+       use Beer qw(round finalround);
 
        sub song {
                for (my $i = 99; $i > 0; $i--) {
                        round $i;
                }
+               finalround;
        }
 
        song;
@@ -67,7 +78,9 @@ Beer - subroutine to output fragment of a drinking song
 =cut
 EOF
 sed -e '
+       s/hello/goodbye/
        s/beer\\/beer,\\/
+       s/more\\/more,\\/
        s/song;/song();/
 ' <Beer.perl >Beer-correct.perl
 
@@ -121,6 +134,10 @@ test_expect_success 'preset perl pattern' '
        test_expect_funcname "sub round {\$" perl
 '
 
+test_expect_success 'perl pattern accepts K&R style brace placement, too' '
+       test_expect_funcname "sub finalround\$" perl
+'
+
 test_expect_success 'perl pattern is not distracted by sub within POD' '
        test_expect_funcname "=head" perl
 '
@@ -129,6 +146,10 @@ test_expect_success 'perl pattern gets full line of POD header' '
        test_expect_funcname "=head1 SYNOPSIS\$" perl
 '
 
+test_expect_success 'perl pattern is not distracted by forward declaration' '
+       test_expect_funcname "package Beer;\$" perl
+'
+
 test_expect_success 'custom pattern' '
        test_config diff.java.funcname "!static
 !String

diff --git a/userdiff.c b/userdiff.c
index 32ead9654aeb2764eb33033a3b5a668904b64826..42b86ac63d734280ac85ea829a910c4aa375dfcd 100644 (file)
--- a/userdiff.c
+++ b/userdiff.c
@@ -60,9 +60,23 @@ PATTERNS("pascal",
         "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
         "|<>|<=|>=|:=|\\.\\."),
 PATTERNS("perl",
-        "^package .*;\n"
-        "^sub .* \\{\n"
-        "^[A-Z]+ \\{\n"        /* BEGIN, END, ... */
+        "^package .*\n"
+        "^sub [[:alnum:]_':]+[ \t]*"
+               "(\\([^)]*\\)[ \t]*)?" /* prototype */
+               /*
+                * Attributes.  A regex can't count nested parentheses,
+                * so just slurp up whatever we see, taking care not
+                * to accept lines like "sub foo; # defined elsewhere".
+                *
+                * An attribute could contain a semicolon, but at that
+                * point it seems reasonable enough to give up.
+                */
+               "(:[^;#]*)?"
+               "(\\{[ \t]*)?" /* brace can come here or on the next line */
+               "(#.*)?$\n" /* comment */
+        "^[A-Z]+[ \t]*"        /* BEGIN, END, ... */
+               "(\\{[ \t]*)?" /* brace can come here or on the next line */
+               "(#.*)?$\n"
         "^=head[0-9] .*",      /* POD */
         /* -- */
         "[[:alpha:]_'][[:alnum:]_']*"