Bug 1733727 part 3: Use StaticAutoPtr to manage lifetime of various "…

…gFoo" static global variables in layout. r=jfkthame This patch doesn't change any user-observable behavior. StaticAutoPtr lets us remove a handful of explicit 'delete' statements, by making deletion happen automatically when these variables are cleared. Differential Revision: https://phabricator.services.mozilla.com/D127337
mozilla · Oct 2, 2021 · f913735 · f913735
1 parent b5c0f07
commit f913735
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Showing 6 changed files with 23 additions and 33 deletions.
diff --git a/layout/generic/nsGfxScrollFrame.cpp b/layout/generic/nsGfxScrollFrame.cpp
@@ -51,6 +51,7 @@
 #include "mozilla/ScrollbarPreferences.h"
 #include "mozilla/ScrollingMetrics.h"
 #include "mozilla/StaticPrefs_browser.h"
+#include "mozilla/StaticPtr.h"
 #include "mozilla/SVGOuterSVGFrame.h"
 #include "mozilla/ViewportUtils.h"
 #include "mozilla/LookAndFeel.h"
@@ -2178,7 +2179,7 @@ class ScrollFrameActivityTracker final
   }
 };
 
-static ScrollFrameActivityTracker* gScrollFrameActivityTracker = nullptr;
+static StaticAutoPtr<ScrollFrameActivityTracker> gScrollFrameActivityTracker;
 
 ScrollFrameHelper::ScrollFrameHelper(nsContainerFrame* aOuter, bool aIsRoot)
     : mHScrollbarBox(nullptr),
@@ -4325,9 +4326,9 @@ nsRect ScrollFrameHelper::RestrictToRootDisplayPort(
 }
 
 /* static */ bool ScrollFrameHelper::ShouldActivateAllScrollFrames() {
-    return (StaticPrefs::apz_wr_activate_all_scroll_frames() ||
-            (StaticPrefs::apz_wr_activate_all_scroll_frames_when_fission() &&
-             FissionAutostart()));
+  return (StaticPrefs::apz_wr_activate_all_scroll_frames() ||
+          (StaticPrefs::apz_wr_activate_all_scroll_frames_when_fission() &&
+           FissionAutostart()));
 }
 
 bool ScrollFrameHelper::DecideScrollableLayer(
@@ -5563,7 +5564,6 @@ void ScrollFrameHelper::Destroy(PostDestroyData& aPostDestroyData) {
     gScrollFrameActivityTracker->RemoveObject(this);
   }
   if (gScrollFrameActivityTracker && gScrollFrameActivityTracker->IsEmpty()) {
-    delete gScrollFrameActivityTracker;
     gScrollFrameActivityTracker = nullptr;
   }
 

diff --git a/layout/painting/ActiveLayerTracker.cpp b/layout/painting/ActiveLayerTracker.cpp
@@ -13,6 +13,7 @@
 #include "mozilla/EffectSet.h"
 #include "mozilla/MotionPathUtils.h"
 #include "mozilla/PodOperations.h"
+#include "mozilla/StaticPtr.h"
 #include "gfx2DGlue.h"
 #include "nsExpirationTracker.h"
 #include "nsContainerFrame.h"
@@ -163,7 +164,7 @@ class LayerActivityTracker final
   bool mDestroying;
 };
 
-static LayerActivityTracker* gLayerActivityTracker = nullptr;
+static StaticAutoPtr<LayerActivityTracker> gLayerActivityTracker;
 
 LayerActivity::~LayerActivity() {
   if (mFrame || mContent) {
@@ -606,9 +607,6 @@ void ActiveLayerTracker::SetCurrentScrollHandlerFrame(nsIFrame* aFrame) {
 }
 
 /* static */
-void ActiveLayerTracker::Shutdown() {
-  delete gLayerActivityTracker;
-  gLayerActivityTracker = nullptr;
-}
+void ActiveLayerTracker::Shutdown() { gLayerActivityTracker = nullptr; }
 
 }  // namespace mozilla
diff --git a/layout/painting/DisplayItemClip.cpp b/layout/painting/DisplayItemClip.cpp
@@ -11,6 +11,7 @@
 #include "mozilla/gfx/2D.h"
 #include "mozilla/gfx/PathHelpers.h"
 #include "mozilla/layers/StackingContextHelper.h"
+#include "mozilla/StaticPtr.h"
 #include "mozilla/webrender/WebRenderTypes.h"
 #include "nsPresContext.h"
 #include "nsCSSRendering.h"
@@ -446,7 +447,7 @@ void DisplayItemClip::MoveBy(const nsPoint& aPoint) {
   }
 }
 
-static DisplayItemClip* gNoClip;
+static StaticAutoPtr<DisplayItemClip> gNoClip;
 
 const DisplayItemClip& DisplayItemClip::NoClip() {
   if (!gNoClip) {
@@ -455,10 +456,7 @@ const DisplayItemClip& DisplayItemClip::NoClip() {
   return *gNoClip;
 }
 
-void DisplayItemClip::Shutdown() {
-  delete gNoClip;
-  gNoClip = nullptr;
-}
+void DisplayItemClip::Shutdown() { gNoClip = nullptr; }
 
 nsCString DisplayItemClip::ToString() const {
   nsAutoCString str;

diff --git a/layout/painting/HitTestInfo.cpp b/layout/painting/HitTestInfo.cpp
@@ -5,14 +5,16 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "HitTestInfo.h"
+
+#include "mozilla/StaticPtr.h"
 #include "mozilla/webrender/WebRenderAPI.h"
 #include "nsDisplayList.h"
 #include "nsIFrame.h"
 #include "mozilla/layers/ScrollableLayerGuid.h"
 
 namespace mozilla {
 
-static const HitTestInfo* gEmptyHitTestInfo = nullptr;
+static StaticAutoPtr<const HitTestInfo> gEmptyHitTestInfo;
 
 const HitTestInfo& HitTestInfo::Empty() {
   if (gEmptyHitTestInfo) {
@@ -22,10 +24,7 @@ const HitTestInfo& HitTestInfo::Empty() {
   return *gEmptyHitTestInfo;
 }
 
-void HitTestInfo::Shutdown() {
-  delete gEmptyHitTestInfo;
-  gEmptyHitTestInfo = nullptr;
-}
+void HitTestInfo::Shutdown() { gEmptyHitTestInfo = nullptr; }
 
 using ViewID = layers::ScrollableLayerGuid::ViewID;
 

diff --git a/layout/painting/nsCSSRendering.cpp b/layout/painting/nsCSSRendering.cpp
@@ -20,6 +20,7 @@
 #include "mozilla/HashFunctions.h"
 #include "mozilla/MathAlgorithms.h"
 #include "mozilla/PresShell.h"
+#include "mozilla/StaticPtr.h"
 #include "mozilla/SVGImageContext.h"
 #include "gfxFont.h"
 #include "ScaledFontBase.h"
@@ -426,7 +427,7 @@ struct InlineBackgroundData {
   }
 };
 
-static InlineBackgroundData* gInlineBGData = nullptr;
+static StaticAutoPtr<InlineBackgroundData> gInlineBGData;
 
 // Initialize any static variables used by nsCSSRendering.
 void nsCSSRendering::Init() {
@@ -435,10 +436,7 @@ void nsCSSRendering::Init() {
 }
 
 // Clean up any global variables used by nsCSSRendering.
-void nsCSSRendering::Shutdown() {
-  delete gInlineBGData;
-  gInlineBGData = nullptr;
-}
+void nsCSSRendering::Shutdown() { gInlineBGData = nullptr; }
 
 /**
  * Make a bevel color

diff --git a/layout/style/nsCSSProps.cpp b/layout/style/nsCSSProps.cpp
@@ -30,13 +30,15 @@
 
 #include "mozilla/Preferences.h"
 #include "mozilla/StaticPrefs_layout.h"
+#include "mozilla/StaticPtr.h"
 
 using namespace mozilla;
 
 static int32_t gPropertyTableRefCount;
-static nsStaticCaseInsensitiveNameTable* gFontDescTable;
-static nsStaticCaseInsensitiveNameTable* gCounterDescTable;
-static nsTHashMap<nsCStringHashKey, nsCSSPropertyID>* gPropertyIDLNameTable;
+static StaticAutoPtr<nsStaticCaseInsensitiveNameTable> gFontDescTable;
+static StaticAutoPtr<nsStaticCaseInsensitiveNameTable> gCounterDescTable;
+static StaticAutoPtr<nsTHashMap<nsCStringHashKey, nsCSSPropertyID>>
+    gPropertyIDLNameTable;
 
 static const char* const kCSSRawFontDescs[] = {
 #define CSS_FONT_DESC(name_, method_) #name_,
@@ -121,13 +123,8 @@ void nsCSSProps::AddRefTable(void) {
 
 void nsCSSProps::ReleaseTable(void) {
   if (0 == --gPropertyTableRefCount) {
-    delete gFontDescTable;
     gFontDescTable = nullptr;
-
-    delete gCounterDescTable;
     gCounterDescTable = nullptr;
-
-    delete gPropertyIDLNameTable;
     gPropertyIDLNameTable = nullptr;
   }
 }