mesa/src/compiler/glsl/glcpp
Emil Velikov 986033a275 configure: allow building with python3
Pretty much all of the scripts are python2+3 compatible.
Check and allow using python3, while adjusting the PYTHON2 refs.

Note:
 - python3.4 is used as it's the earliest supported version
 - python2 chosen prior to python3

v2: use python2 by default

Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Eric Engestrom <eric.engestrom@intel.com>
2018-10-31 19:15:50 +00:00
..
tests configure: allow building with python3 2018-10-31 19:15:50 +00:00
.gitignore
glcpp-lex.l glsl: fixer lexer for unreachable defines 2018-09-06 10:13:21 +10:00
glcpp-parse.y glsl: ignore trailing whitespace when define redefined 2018-10-10 15:08:32 +11:00
glcpp.c Fix scons build 2018-04-12 19:55:01 -04:00
glcpp.h glsl: fixer lexer for unreachable defines 2018-09-06 10:13:21 +10:00
meson.build meson: Don't build glsl compiler tests unless OpenGL is enabled 2018-10-09 08:56:00 -07:00
pp.c mesa: include mtypes.h less 2018-04-12 19:31:30 -04:00
README

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).