glcpp: Reject garbage after #else and #endif tokens

Previously we were accepting garbage after #else and #endif tokens when
the previous preprocessor conditional evaluated to false (eg, #if 0).

When the preprocessor hits a false conditional, it switches the lexer
into the SKIP state, in which it ignores non-control tokens. The parser
pops the SKIP state off the stack when it reaches the associated #elif,
#else, or #endif. Unfortunately, that meant that it only left the SKIP
state after the lexing the entire line containing the #token and thus
would accept garbage after the #token.

To fix this we use a mid-rule, which is executed immediately after the
#token is parsed.

NOTE: This is a candidate for the stable branch
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=56442
Fixes: preprocess17_frag.test from oglconform
Reviewed-by: Carl Worth <[email protected]> (glcpp-parse.y)
Acked-by: Ian Romanick <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/glsl/glcpp/glcpp-parse.y b/src/glsl/glcpp/glcpp-parse.y
index 40c43c63efd..16d29650dfe 100644
--- a/src/glsl/glcpp/glcpp-parse.y
+++ b/src/glsl/glcpp/glcpp-parse.y
@@ -327,12 +327,12 @@ control_line:
 			glcpp_warning(& @1, parser, "ignoring illegal #elif without expression");
 		}
 	}
-|	HASH_ELSE NEWLINE {
+|	HASH_ELSE {
 		_glcpp_parser_skip_stack_change_if (parser, & @1, "else", 1);
-	}
-|	HASH_ENDIF NEWLINE {
+	} NEWLINE
+|	HASH_ENDIF {
 		_glcpp_parser_skip_stack_pop (parser, & @1);
-	}
+	} NEWLINE
 |	HASH_VERSION integer_constant NEWLINE {
 		macro_t *macro = hash_table_find (parser->defines, "__VERSION__");
 		if (macro) {