mesa/src/compiler/glsl/glcpp
Timothy Arceri d4f79e995f glsl: use ralloc_str_append() rather than ralloc_asprintf_rewrite_tail()
The Deus Ex: Mankind Divided shaders go from spending ~20 seconds
in the GLSL IR compilers front-end down to ~18.5 seconds on a
Ryzen 1800X.

Tested by compiling once with shader-db then deleting the index file
from the shader cache and compiling again.

v2:
 - fix rebasing issue in v1

Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
2017-08-11 10:43:34 +10:00
..
tests Fix glcpp test expectations 2017-06-08 09:46:36 +02:00
.gitignore glsl: move to compiler/ 2016-01-26 16:08:33 +00:00
glcpp-lex.l glcpp: Allow vertical tab and form feed characters in GLSL 2017-01-04 14:40:48 -08:00
glcpp-parse.y glsl: use ralloc_str_append() rather than ralloc_asprintf_rewrite_tail() 2017-08-11 10:43:34 +10:00
glcpp.c glsl: reuse main extension table to appropriately restrict extensions 2016-07-23 13:48:04 -04:00
glcpp.h glsl: Add "built-in" functions to do 64x64 => 64 multiplication 2017-01-20 15:41:23 -08:00
pp.c glcpp: Skip unnecessary line continuations removal 2017-05-22 12:34:28 +10:00
README glsl: move to compiler/ 2016-01-26 16:08:33 +00:00

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).