Files
mesa/src/glsl/glcpp
Carl Worth 2fdc1f50c4 glsl/glcpp: Add a -d/--debug option to the standalone glcpp program
The verbose debug output from the parser is quite useful when debugging, and
having this available as a command-line option is much more convenient than
manually forcing this into the code when needed, (which is what I had been
doing for too long previously).

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
2014-07-29 15:11:49 -07:00
..

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).