glcpp: Add support for __LINE__ and __FILE__ macros

These tokens are easy to expand by just looking at the current, tracked
location values, (and no need to look anything up in the hash table).

Add a test which verifies __LINE__ with several values, (and verifies __FILE__
for the single value of 0). Our testing framework isn't sophisticated enough
here to have a test with multiple file inputs.

This commit fixes part of es3conform's preprocess16_frag test.

Reviewed-by: Matt Turner <mattst88@gmail.com>

src/glsl/glcpp/glcpp-parse.y

@@ -1528,8 +1528,37 @@ _glcpp_parser_expand_node (glcpp_parser_t *parser,
 		return NULL;
 	}
 
-	/* Look up this identifier in the hash table. */
 	identifier = token->value.str;
+
+	/* Special handling for __LINE__ and __FILE__, (not through
+	 * the hash table). */
+	if (strcmp(identifier, "__LINE__") == 0) {
+		token_list_t *replacement;
+		token_t *value;
+
+		replacement = _token_list_create (parser);
+		value = _token_create_ival (parser, INTEGER,
+					    node->token->location.first_line);
+		_token_list_append (replacement, value);
+
+		*last = node;
+		return replacement;
+	}
+
+	if (strcmp(identifier, "__FILE__") == 0) {
+		token_list_t *replacement;
+		token_t *value;
+
+		replacement = _token_list_create (parser);
+		value = _token_create_ival (parser, INTEGER,
+					    node->token->location.source);
+		_token_list_append (replacement, value);
+
+		*last = node;
+		return replacement;
+	}
+
+	/* Look up this identifier in the hash table. */
 	macro = hash_table_find (parser->defines, identifier);
 
 	/* Not a macro, so no expansion needed. */

src/glsl/glcpp/tests/113-line-and-file-macros.c

@@ -0,0 +1,7 @@
+1. Number of dalmations: __LINE__ __FILE__ __LINE__
+2. Nominal visual acuity: __LINE__ __FILE__ / __LINE__ __FILE__
+3. Battle of Thermopylae, as film: __LINE__ __FILE__ __FILE__
+4. HTTP code for "Not Found": __LINE__ __FILE__ __LINE__
+5. Hexadecimal for 20560: __LINE__ __FILE__ __LINE__ __FILE__
+6: Zip code for Nortonville, KS: __LINE__ __LINE__ __FILE__ __LINE__ __FILE__
+7. James Bond, as a number: __FILE__ __FILE__ __LINE__

src/glsl/glcpp/tests/113-line-and-file-macros.c.expected

@@ -0,0 +1,8 @@
+1. Number of dalmations: 1 0 1
+2. Nominal visual acuity: 2 0 / 2 0
+3. Battle of Thermopylae, as film: 3 0 0
+4. HTTP code for "Not Found": 4 0 4
+5. Hexadecimal for 20560: 5 0 5 0
+6: Zip code for Nortonville, KS: 6 6 0 6 0
+7. James Bond, as a number: 0 0 7
+