[PATCH] Teach git diff about Objective-C syntax

[Jonathan del Strother <jon.delStrother@bestbefore.tv>]

Add support for recognition of Objective-C class & instance methods, C functions, and class implementation/interfaces.

Signed-off-by: Jonathan del Strother <jon.delStrother@bestbefore.tv>
---

This version of the patch adds the negate line to avoid picking up if()/while()/etc statements as funcnames
I also took the liberty of replacing the invisible tab characters in the java pattern with \t's - is that OK?

 Documentation/gitattributes.txt |    2 ++
 diff.c                          |   19 ++++++++++++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 6f3551d..c1f13e2 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -315,6 +315,8 @@ patterns are available:
 
 - `java` suitable for source code in the Java language.
 
+- `objc` suitable for source code in the Objective-C language.
+
 - `pascal` suitable for source code in the Pascal/Delphi language.
 
 - `php` suitable for source code in the PHP language.
diff --git a/diff.c b/diff.c
index 998dcaa..fdfdf26 100644
--- a/diff.c
+++ b/diff.c
@@ -1398,17 +1398,26 @@ static struct builtin_funcname_pattern {
 } builtin_funcname_pattern[] = {
 	{ "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
 	{ "html", "^\\s*\\(<[Hh][1-6]\\s.*>.*\\)$" },
-	{ "java", "!^[ 	]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
+
+	{ "java", "!^[ \t]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
 			"new\\|return\\|switch\\|throw\\|while\\)\n"
-			"^[ 	]*\\(\\([ 	]*"
+			"^[ \t]*\\(\\([ \t]*"
 			"[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
-			"[ 	]*([^;]*\\)$" },
+			"[ \t]*([^;]*\\)$" },
+
+	{ "objc", "![ \t]*\\(do\\|for\\|if\\|else\\|return\\|switch\\|while\\)\n" /* Negate C statements that can look like functions */
+			"^[ \t]*\\([-+][ \t]*([ \t]*[A-Za-z_][A-Za-z_0-9]*.*).*\\)$" /* Objective-C methods */
+			"\\|"
+			"^[ \t]*\\(\\([ \t]*[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}[ \t]*([^;]*\\)$" /* C functions */
+			"\\|"
+			"^@\\(implementation\\|interface\\|protocol\\).*"}, /* Objective-C class/protocol definitions */
+
 	{ "pascal", "^\\(\\(procedure\\|function\\|constructor\\|"
 			"destructor\\|interface\\|implementation\\|"
 			"initialization\\|finalization\\)[ \t]*.*\\)$"
 			"\\|"
-			"^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
-			},
+			"^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"},
+
 	{ "php", "^[\t ]*\\(\\(function\\|class\\).*\\)" },
 	{ "python", "^\\s*\\(\\(class\\|def\\)\\s.*\\)$" },
 	{ "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
-- 
1.6.0.2.250.g2fdd2.dirty