diff: Detect Objective-C methods

When searching back for function definitions, consider lines starting
with '+' and '-', this allows us to pick up Objective-C methods as well
as C style function definitions.

Reviewed by:	bapt
Sponsored by:	Klara Inc.
Differential Revision:	https://reviews.freebsd.org/D34202

usr.bin/diff/diff.1

@@ -396,8 +396,8 @@ file name and time in the context or unified diff header.
 With unified and context diffs, show with each change
 the first 40 characters of the last line before the context beginning
 with a letter, an underscore or a dollar sign.
-For C source code following standard layout conventions, this will
-show the prototype of the function the change applies to.
+For C and Objective-C source code following standard layout conventions, this
+will show the prototype of the function the change applies to.
 .It Fl T -initial-tab
 Print a tab rather than a space before the rest of the line for the
 normal, context or unified output formats.

usr.bin/diff/diffreg.c

@@ -1419,7 +1419,8 @@ match_function(const long *f, int pos, FILE *fp)
 			strlcpy(lastbuf, buf, sizeof(lastbuf));
 			lastmatchline = pos;
 			return (lastbuf);
-		} else if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
+		} else if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$'
+			|| buf[0] == '-' || buf[0] == '+') {
 			if (begins_with(buf, "private:")) {
 				if (!state)
 					state = " (private)";

usr.bin/diff/tests/Makefile

@@ -27,7 +27,14 @@ ${PACKAGE}FILES+=	\
 	header_ns.out \
 	ifdef.out \
 	group-format.out \
-	strip_o.out
+	strip_o.out \
+	functionname.in \
+	functionname_c.in \
+	functionname_c.out \
+	functionname_objcclassm.in \
+	functionname_objcclassm.out \
+	functionname_objcm.in \
+	functionname_objcm.out
 
 NETBSD_ATF_TESTS_SH+=	netbsd_diff_test
 

usr.bin/diff/tests/diff_test.sh

@@ -19,6 +19,7 @@ atf_test_case label
 atf_test_case report_identical
 atf_test_case non_regular_file
 atf_test_case binary
+atf_test_case functionname
 
 simple_body()
 {
@@ -278,6 +279,23 @@ binary_body()
 	atf_check -o inline:"176c\nx\n.\n" -s exit:1 diff -ae A B
 }
 
+functionname_body()
+{
+	atf_check -o empty -x "which diff"
+
+	atf_check -o file:$(atf_get_srcdir)/functionname_c.out -s exit:1 \
+		diff -u -p -L functionname.in -L functionname_c.in \
+		"$(atf_get_srcdir)/functionname.in" "$(atf_get_srcdir)/functionname_c.in"
+
+	atf_check -o file:$(atf_get_srcdir)/functionname_objcm.out -s exit:1 \
+		diff -u -p -L functionname.in -L functionname_objcm.in \
+		"$(atf_get_srcdir)/functionname.in" "$(atf_get_srcdir)/functionname_objcm.in"
+
+	atf_check -o file:$(atf_get_srcdir)/functionname_objcclassm.out -s exit:1 \
+		diff -u -p -L functionname.in -L functionname_objcclassm.in \
+		"$(atf_get_srcdir)/functionname.in" "$(atf_get_srcdir)/functionname_objcclassm.in"
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case simple
@@ -299,4 +317,5 @@ atf_init_test_cases()
 	atf_add_test_case report_identical
 	atf_add_test_case non_regular_file
 	atf_add_test_case binary
+	atf_add_test_case functionname
 }

usr.bin/diff/tests/functionname.in

@@ -0,0 +1,29 @@
+static void
+doSomethingThenPrintHello(int test)
+{
+	test = test << 4;
+	if (test % 8 == 6) {
+		return;
+	}
+
+	print("goodbye\n");
+}
+
+
+- (long) readOffset:(FILE*)file
+{
+	if( version >= 11){
+		long offset;
+		fread(&offset, sizeof(long), 1, file);
+		return offset;
+	} else {
+		int offset;
+		fread(&offset, sizeof(int), 1, file);
+		return offset;
+	}
+}
+
++ (BOOL) isEdible:(NSString *)mushroom
+{
+	return TRUE;
+}

usr.bin/diff/tests/functionname_c.in

@@ -0,0 +1,29 @@
+static void
+doSomethingThenPrintHello(int test)
+{
+	test = test << 4;
+	if (test % 8 == 6) {
+		return;
+	}
+
+	print("hello\n");
+}
+
+
+- (long) readOffset:(FILE*)file
+{
+	if( version >= 11){
+		long offset;
+		fread(&offset, sizeof(long), 1, file);
+		return offset;
+	} else {
+		int offset;
+		fread(&offset, sizeof(int), 1, file);
+		return offset;
+	}
+}
+
++ (BOOL) isEdible:(NSString *)mushroom
+{
+	return TRUE;
+}

usr.bin/diff/tests/functionname_c.out

@@ -0,0 +1,11 @@
+--- functionname.in
++++ functionname_c.in
+@@ -6,7 +6,7 @@ doSomethingThenPrintHello(int test)
+ 		return;
+ 	}
+ 
+-	print("goodbye\n");
++	print("hello\n");
+ }
+ 
+ 

usr.bin/diff/tests/functionname_objcclassm.in

@@ -0,0 +1,31 @@
+static void
+doSomethingThenPrintHello(int test)
+{
+	test = test << 4;
+	if (test % 8 == 6) {
+		return;
+	}
+
+	print("goodbye\n");
+}
+
+
+- (long) readOffset:(FILE*)file
+{
+	if( version >= 11){
+		long offset;
+		fread(&offset, sizeof(long), 1, file);
+		return offset;
+	} else {
+		int offset;
+		fread(&offset, sizeof(int), 1, file);
+		return offset;
+	}
+}
+
++ (BOOL) isEdible:(NSString *)mushroom
+{
+	/* With a solid guide book (such as Phillips 2006) assume we can't eat
+	 * the fungus */
+	return FALSE;
+}

usr.bin/diff/tests/functionname_objcclassm.out

@@ -0,0 +1,11 @@
+--- functionname.in
++++ functionname_objcclassm.in
+@@ -25,5 +25,7 @@ + (BOOL) isEdible:(NSString *)mushroom
+ 
+ + (BOOL) isEdible:(NSString *)mushroom
+ {
+-	return TRUE;
++	/* With a solid guide book (such as Phillips 2006) assume we can't eat
++	 * the fungus */
++	return FALSE;
+ }

usr.bin/diff/tests/functionname_objcm.in

@@ -0,0 +1,29 @@
+static void
+doSomethingThenPrintHello(int test)
+{
+	test = test << 4;
+	if (test % 8 == 6) {
+		return;
+	}
+
+	print("goodbye\n");
+}
+
+
+- (long) readOffset:(FILE*)file
+{
+	if( version >= 11){
+		long offset;
+		fread(&offset, sizeof(long), 1, file);
+		return offset;
+	} else {
+		int offset;
+		fread(&offset-1, sizeof(int), 1, file);
+		return offset;
+	}
+}
+
++ (BOOL) isEdible:(NSString *)mushroom
+{
+	return TRUE;
+}

usr.bin/diff/tests/functionname_objcm.out

@@ -0,0 +1,11 @@
+--- functionname.in
++++ functionname_objcm.in
+@@ -18,7 +18,7 @@ - (long) readOffset:(FILE*)file
+ 		return offset;
+ 	} else {
+ 		int offset;
+-		fread(&offset, sizeof(int), 1, file);
++		fread(&offset-1, sizeof(int), 1, file);
+ 		return offset;
+ 	}
+ }