Making it easier to work with shaders https://git.yummers.dev/slang.git/atom?h=master 2018-03-29T22:47:58+00:00 2018-03-29T22:47:58+00:00 Tim Foley tfoleyNV@users.noreply.github.com 2018-03-29T22:47:58+00:00 urn:sha1:87c50cf1644454cdc9e7f6d1262bee29bfc86e80 Fixes #463 Some of the attributes were failing to check for a `null` result from `checkConstantIntVal`, and so they crashed when a bad expression was used in an attribute. The particular way this had been triggered was that a user put an HLSL geometry shader in the same file with other code, using an entry point like: ```hlsl [instance(COUNT)] void myGeometryShader(...) {...} ``` They then defined `COUNT` as a preprocessor macro when compiling using the GS, but left it undefined otherwise. The result was that the argument to the `instance` attribute would fail to type check, and thus wouldn't count as a constant integer value, so that `checkConstantIntVal` returns `null` and results in the crash. The workaround for the user is to always define `COUNT`, even when not compiling the GS. The fix in the compiler is to guard against `null` in these cases and bail out of attribute checking. I also implemented logic so that `CheckIntegerConstantExpression` (which is invoked by `checkConstantIntVal`) will not produce an additional error message if the underlying expression failed to type check. In this casem the user will get an `undefined identifier: COUNT` error message, and we don't need to waste their time by also telling them that this isn't a compile-time constant expression.