mesa/src/glsl/glcpp
Erik Faye-Lund eb212c5a30 glcpp: error on multiple #else/#elif directives
The preprocessor currently accepts multiple else/elif-groups
per if-section. The GLSL-preprocessor is defined by the C++
specification, which defines the following parse-rule:

if-section:
	if-group elif-groups(opt) else-group(opt) endif-line

This clearly only allows a single else-group, that has to come
after any elif-groups.

So let's modify the code to follow the specification. Add test
to prevent regressions.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Carl Worth <cworth@cworth.org>

Cc: 10.0 <mesa-stable@lists.freedesktop.org>
2014-01-02 14:22:58 -08:00
..
tests glcpp: error on multiple #else/#elif directives 2014-01-02 14:22:58 -08:00
.gitignore glcpp: Add back tests/*.out to .gitignore 2013-01-11 11:49:33 +01:00
glcpp-lex.l glcpp: Replace multi-line comment with a space (even as part of macro definition) 2014-01-02 14:15:51 -08:00
glcpp-parse.y glcpp: error on multiple #else/#elif directives 2014-01-02 14:22:58 -08:00
glcpp.c glcpp: Add --disable-line-continuations argument to standalone glcpp 2013-01-11 13:55:41 -08:00
glcpp.h glcpp: error on multiple #else/#elif directives 2014-01-02 14:22:58 -08:00
pp.c glcpp: Fix post-decrement underflow in loop-control variable 2013-06-03 13:33:31 -07:00
README glcpp: Update README for new support of __LINE__ and __FILE__. 2012-11-29 13:03:02 -08:00

glcpp -- GLSL "C" preprocessor

This is a simple preprocessor designed to provide the preprocessing
needs of the GLSL language. The requirements for this preprocessor are
specified in the GLSL 1.30 specification availble from:

http://www.opengl.org/registry/doc/GLSLangSpec.Full.1.30.10.pdf

This specification is not precise on some semantics, (for example,
#define and #if), defining these merely "as is standard for C++
preprocessors". To fill in these details, I've been using a draft of
the C99 standard as available from:

http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf

Any downstream compiler accepting output from glcpp should be prepared
to encounter and deal with the following preprocessor macros:

	#line
	#pragma
	#extension

All other macros will be handled according to the GLSL specification
and will not appear in the output.

Known limitations
-----------------
A file that ends with a function-like macro name as the last
non-whitespace token will result in a parse error, (where it should be
passed through as is).