Bug 296895 – AX: fix broken and expensive ASSERTS in accessibility code

• Component: Accessibility
• Status: RESOLVED FIXED

[Dominic Mazzoni]

We have ~100 ASSERTS in WebCore/accessibility, and of those I found 6 that are broken - they're asserting on live pages - and about 10 that are called way too often, hundreds of thousands of times per minute.

If we sequester those - the broken ones and the ones called way too often - we'll be able to run release builds with assertions enabled all of the time.

[Radar WebKit Bug Importer]

<rdar://problem/157501091>

[Dominic Mazzoni]

Pull request: https://github.com/WebKit/WebKit/pull/48918

[EWS]

Committed 298252@main (ab66a869bd96): <https://commits.webkit.org/298252@main>

Reviewed commits have been landed. Closing PR #48918 and removing active labels.

[Philippe Normand]

This introduced new clang linux warnings:

In file included from /var/home/phil/WebKit/local-build-gtk/WebKitBuild/GTK/Release/WebCore/DerivedSources/unified-sources/UnifiedSource-aba958d6-3.cpp:7:
/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp:730:18: warning: address of function 'isAccessibilityLogChannelEnabled' will always evaluate to 'true' [-Wpointer-bool-conversion]
  730 |         do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(isTableComponent(child) || isTableComponent(*this) || child.parentObject() == this)), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp", "CODE_LINE=" "730", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp", 730, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |              ~~  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp:730:18: note: prefix with the address-of operator to silence this warning
  730 |         do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(isTableComponent(child) || isTableComponent(*this) || child.parentObject() == this)), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp", "CODE_LINE=" "730", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp", 730, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |                  ^
      |                  &
/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp:730:18: note: suffix with parentheses to turn this into a function call
  730 |         do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(isTableComponent(child) || isTableComponent(*this) || child.parentObject() == this)), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp", "CODE_LINE=" "730", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp", 730, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |                  ^
      |                                                  ()
1 warning generated.

In file included from /var/home/phil/WebKit/local-build-gtk/WebKitBuild/GTK/Release/WebCore/DerivedSources/unified-sources/UnifiedSource-aba958d6-1.cpp:5:
/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp:1045:14: warning: address of function 'isAccessibilityLogChannelEnabled' will always evaluate to 'true' [-Wpointer-bool-conversion]
 1045 |     do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(!get(renderer))), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp", "CODE_LINE=" "1045", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp", 1045, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |          ~~  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp:1045:14: note: prefix with the address-of operator to silence this warning
 1045 |     do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(!get(renderer))), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp", "CODE_LINE=" "1045", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp", 1045, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |              ^
      |              &
/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp:1045:14: note: suffix with parentheses to turn this into a function call
 1045 |     do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(!get(renderer))), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp", "CODE_LINE=" "1045", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp", 1045, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |              ^
      |                                              ()
In file included from /var/home/phil/WebKit/local-build-gtk/WebKitBuild/GTK/Release/WebCore/DerivedSources/unified-sources/UnifiedSource-aba958d6-1.cpp:7:
/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp:246:18: warning: address of function 'isAccessibilityLogChannelEnabled' will always evaluate to 'true' [-Wpointer-bool-conversion]
  246 |         do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(is<AccessibilityObject>(startObject))), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp", "CODE_LINE=" "246", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp", 246, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |              ~~  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp:246:18: note: prefix with the address-of operator to silence this warning
  246 |         do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(is<AccessibilityObject>(startObject))), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp", "CODE_LINE=" "246", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp", 246, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |                  ^
      |                  &
/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp:246:18: note: suffix with parentheses to turn this into a function call
  246 |         do { if (isAccessibilityLogChannelEnabled) { do { if (__builtin_expect(!!(!(is<AccessibilityObject>(startObject))), 0)) do { if (LogAccessibility.state != WTFLogChannelState::Off) sd_journal_send_with_location("CODE_FILE=" "/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp", "CODE_LINE=" "246", __func__, "WEBKIT_SUBSYSTEM=" "WebKitGTK", "WEBKIT_CHANNEL=%s", LogAccessibility.name, "PRIORITY=%i", 3, "MESSAGE=" "BROKEN ASSERTION FAILED in %s(%d) : %s\n", "/var/home/phil/WebKit/Source/WebCore/accessibility/AXSearchManager.cpp", 246, __PRETTY_FUNCTION__, nullptr); } while (0); } while (0); } } while (0);
      |                  ^
      |                                                  ()
2 warnings generated.

[Philippe Normand]

https://github.com/WebKit/WebKit/pull/49007