From bc8721f16f2f4a08e6ad935723cc52de1748b63f Mon Sep 17 00:00:00 2001 From: Carl Worth Date: Tue, 1 Jul 2014 15:04:38 -0700 Subject: [PATCH] glsl/glcpp: Add flex options to eliminate the default rule. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We've had multiple bugs in the past where we have been inadvertently matching the default rule, (which we never want to do). We recently added a catch-all rule to avoid this, (and made this rule robust for future start conditions). Kristian pointed out that flex allows us to go one step better. This syntax: %option warn nodefault instructs flex to not generate the default rule at all. Further, flex will generate a warning at compile time if the set of rules we provide are inadequate, (such that it would be possible for the default rule to be matched). With this warning in place, I found that the catch-all rule was in fact missing something. The catch-all rule uses a pattern of "." which doesn't match newlines. So here we extend the newline-matching rule to all start conditions. That is enough to convince flex that it really doesn't need any default rule. Reviewed-by: Kenneth Graunke Reviewed-by: Kristian Høgsberg --- src/glsl/glcpp/glcpp-lex.l | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/glsl/glcpp/glcpp-lex.l b/src/glsl/glcpp/glcpp-lex.l index 79a7ad7..4b9ab23 100644 --- a/src/glsl/glcpp/glcpp-lex.l +++ b/src/glsl/glcpp/glcpp-lex.l @@ -160,6 +160,7 @@ glcpp_lex_update_state_per_token (glcpp_parser_t *parser, int token) %option prefix="glcpp_" %option stack %option never-interactive +%option warn nodefault /* Note: When adding any start conditions to this list, you must also * update the "Internal compiler error" catch-all rule near the end of @@ -516,7 +517,7 @@ HEXADECIMAL_INTEGER 0[xX][0-9a-fA-F]+[uU]? /* We preserve all newlines, even between #if 0..#endif, so no skipping.. */ -[\r\n] { +<*>[\r\n] { if (parser->commented_newlines) { BEGIN NEWLINE_CATCHUP; } -- 2.7.4