Commit 9733ceefa455165bbed9cd099244eada821fa96d
2017-05-11T19:14:35
Initialize uninitialized locals in GLSL output Guarantee that local variables are initialized before they are used in GLSL output. In HLSL output all variables were already being initialized. Locals are initialized using an AST transform. The local variable init can only be run after some simplification of the AST, so that it is able to handle complex cases like: for (int i[2], j = i[0]; i[0] < 3; ++i[0]) { } If we're dealing with ESSL 1.00 which lacks array constructors, in this kind of case the uninitialized array initialization code needs to be hoisted out of the loop init statement, and the code also needs to make sure that j's initializer is run after i is initialized. Another complex case involves nameless structs. This can be an issue also in ESSL 3.00 and above: for (struct { float f; } s; s.f < 1.0; ++s.f) { } Since the struct doesn't have a name, its constructor can not be used. We solve this by initializing the struct members individually, similarly to how arrays are initialized in ESSL 1.00. Initializing local variables is disabled on Mac and Android for now. On Mac, invalid behavior was exposed in the WebGL 2.0 tests when enabling it. On Android, the dEQP test runs failed for an unknown reason. Bugs have been opened to resolve these issues later. BUG=angleproject:1966 TEST=angle_end2end_tests, WebGL conformance tests Change-Id: Ic06927f5b6cc9619bc82c647ee966605cd80bab2 Reviewed-on: https://chromium-review.googlesource.com/504728 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>