From f9c99aefea85fe23bbe4b7802542eaf8f70d6798 Mon Sep 17 00:00:00 2001 From: Carl Worth Date: Wed, 18 Jun 2014 17:03:19 -0700 Subject: [PATCH] glsl/glcpp: Add a catch-all rule for unexpected characters. In some of the recent glcpp bug-fixing, we found that glcpp was emitting unrecognized characters from the input source file to stdout, and dropping them from the source passed onto the compiler proper. This was obviously confusing, and totally undesired. The bogus behavior comes from an implicit default rule in flex, which is that any unmatched character is implicitly matched and printed to stdout. To avoid this implicit matching and printing, here we add an explicit catch-all rule. If this rule ever matches it prints an internal compiler error. The correct response for any such error is fixing glcpp to handle the unexpected character in the correct way. Reviewed-by: Jordan Justen --- src/glsl/glcpp/glcpp-lex.l | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/src/glsl/glcpp/glcpp-lex.l b/src/glsl/glcpp/glcpp-lex.l index cb5ee99..1c3e0ab 100644 --- a/src/glsl/glcpp/glcpp-lex.l +++ b/src/glsl/glcpp/glcpp-lex.l @@ -161,6 +161,10 @@ glcpp_lex_update_state_per_token (glcpp_parser_t *parser, int token) %option stack %option never-interactive + /* Note: When adding any start conditions to this list, you must also + * update the "Internal compiler error" catch-all rule near the end of + * this file. */ + %x DONE COMMENT HASH UNREACHABLE DEFINE NEWLINE_CATCHUP SPACE [[:space:]] @@ -534,6 +538,15 @@ HEXADECIMAL_INTEGER 0[xX][0-9a-fA-F]+[uU]? RETURN_TOKEN (NEWLINE); } + /* This is a catch-all to avoid the annoying default flex action which + * matches any character and prints it. If any input ever matches this + * rule, then we have made a mistake above and need to fix one or more + * of the preceding patterns to match that input. */ + +. { + glcpp_error(yylloc, yyextra, "Internal compiler error: Unexpected character: %s", yytext); +} + /* We don't actually use the UNREACHABLE start condition. We only have this action here so that we can pretend to call some generated functions, (to avoid "defined but not used" -- 2.7.4