Initialize three locals to avoid the risk of uninitialized reads.

/analyze recently reported two new warnings about reading from
potentially uninitialized local variables:

src\third_party\skia\src\gpu\grclipmaskmanager.cpp(290) :
warning C6001: Using uninitialized memory 'requiresAA'.
src\third_party\skia\src\gpu\grclipmaskmanager.cpp(336) :
warning C6001: Using uninitialized memory 'genID'.

It is not clear whether the uninitialized reads can actually happen,
but the guarantees seem sufficiently non-obvious that the prudent thing
to do to guarantee future stability is to initialized them -- it's
cheap. I also initialized initialState because it seemed to fall in
the same class, despite there being no warning for it.

BUG=427616

Review URL: https://codereview.chromium.org/957133002

diff --git a/src/gpu/GrClipMaskManager.cpp b/src/gpu/GrClipMaskManager.cpp
index 0084c2b..a39c4a3 100644 (file)
--- a/src/gpu/GrClipMaskManager.cpp
+++ b/src/gpu/GrClipMaskManager.cpp
@@ -218,10 +218,10 @@ bool GrClipMaskManager::setupClipping(GrPipelineBuilder* pipelineBuilder,
     }
 
     GrReducedClip::ElementList elements(16);
-    int32_t genID;
-    GrReducedClip::InitialState initialState;
+    int32_t genID = 0;
+    GrReducedClip::InitialState initialState = GrReducedClip::kAllIn_InitialState;
     SkIRect clipSpaceIBounds;
-    bool requiresAA;
+    bool requiresAA = false;
     GrRenderTarget* rt = pipelineBuilder->getRenderTarget();
 
     // GrDrawTarget should have filtered this for us
@@ -239,7 +239,6 @@ bool GrClipMaskManager::setupClipping(GrPipelineBuilder* pipelineBuilder,
                 // we should have handled this case above
                 SkASSERT(false);
             case GrClip::kIRect_ClipType: {
-                initialState = GrReducedClip::kAllIn_InitialState;
                 clipSpaceIBounds = clip.irect();
                 SkNEW_INSERT_AT_LLIST_HEAD(&elements,
                                            Element,
@@ -247,7 +246,6 @@ bool GrClipMaskManager::setupClipping(GrPipelineBuilder* pipelineBuilder,
                                             SkRegion::kIntersect_Op, false));
             } break;
             case GrClip::kRect_ClipType: {
-                initialState = GrReducedClip::kAllIn_InitialState;
                 clipSpaceIBounds.setLTRB(SkScalarCeilToInt(clip.rect().fLeft),
                                          SkScalarCeilToInt(clip.rect().fTop),
                                          SkScalarCeilToInt(clip.rect().fRight),