On Tue, Jun 09 2015, Ian Romanick wrote:
>> From section 3.4 ("Preprocessor") of the GLSL ES 3.00 specification:
>> "#line must have, after macro substitution, one of the following forms:
>> #line line
>> #line line source-string-number
>> where line and source-string-number are constant integral
>> expressions."
...
>> From section 4.3.3 ("Constant Expressions") of the same specification:
>> "A constant integral expression is a constant expression that evaluates
>> to a scalar signed or unsigned integer."Yes. That's an extremely unfortunate piece of the specification. This, together with unary operators introduces inherent ambiguity into the grammar. Just think about things like: #line 2-1+5 #line 2 -1+5 #line 2-1 +5 #line 2-1+5 3 #line 2 -1+5 3 #line 2-1 +5 3 That's off the top of my head. I'll dig through some old branches to see if I have some other gems for testing this stuff. > FFS. I can't believe they have a test for this. For what it's worth, > this makes the grammar non-LALR. Not too long ago it came up for a vote > to remove this since it does not work on *ANY* desktop OpenGL > implementation. While there was a majority vote to remove it, it was > not a large enough majority (by a single vote). It is also a deviation > from C / C++ preprocessors. > > Carl spent some time on this, and he couldn't find a way to make it work > without adding significant bison warnings or have it fail for some > cases. I would definitely push back against anyone enforcing this piece of the specification in a test suite. It's language that really doesn't belong in the specification. But I'll also take a look at this patch. Thanks for bringing it to my attention, Ian. -Carl
pgpo0L7QdI8dN.pgp
Description: PGP signature
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
