glsl: Fix crashes caused by Bison error messages involving "'%'".
Invalid shaders containing the character % at an unexpected location
would cause Bison to call yyerror with a message of:
syntax error, unexpected '%'
Bison expects yyerror() to take a string, while _mesa_glsl_error() is a
printf-style function. This hit the classic printf string escape issue:
_mesa_glsl_error(loc, state, "unexpected '%'"); // invalid!
_mesa_glsl_error(loc, state, "%s", "unexpected '%'"); // correct.
This caused assertion failures after ralloc_asprintf_append called
vsnprintf to determine the length of the text that would be printed:
vsnprintf would see the invalid format and return -1, an invalid length.
The solution is to define a proper yyerror() wrapper function that calls
_mesa_glsl_error with the "%s". Since we compile with -p "_mesa_glsl",
yyerror is defined as:
#define yyerror _mesa_glsl_error
So we have to #undef yyerror in order to be able to declare it.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43564
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Acked-by: Paul Berry <stereotype441@gmail.com>
1 file changed