SkRuntimeEffect::MakeForXxxxx compiles its shaders before MakeTraced()
is invoked, with optimizations enabled. When MakeTraced() is called,
we recompile the shader with optimizations disabled; this allows us to
present the user with a shader that is as close to the original as
possible. (This obviously costs time, but debug trace generation isn't
focused on speed.)
Note that in some rare instances, disabling optimizations can cause
compilation to fail (e.g. optimization can simplify control flow and
eliminate "unreachable" paths). In those cases, we fall back to the
existing behavior of debugging an optimized shader.
Change-Id: Iba0f31bc42374c7048694fde5415b122177a9a68
Bug: skia:12666
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/489716
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
65aae8a51a