Changeset 162711 in webkit for trunk/Source/JavaScriptCore/jit

Timestamp:

Jan 24, 2014, 11:07:31 AM (11 years ago)

Author:

[email protected]

Message:

Removing the need for Debugger* and m_shouldPause op_debug check.
<​https://webkit.org/b/127532>

Reviewed by Geoffrey Garen.

This patch replaces the checking of the Debugger::m_shouldPause flag
with a procedure to set a SteppingMode flag on all CodeBlocks under
the management of the debugger. This simplifies the op_debug checking
logic in all the execution engines.

• bytecode/CodeBlock.cpp:
• bytecode/CodeBlock.h:

(JSC::CodeBlock::hasDebuggerRequests):
(JSC::CodeBlock::debuggerRequestsAddress):
(JSC::CodeBlock::setSteppingMode):
(JSC::CodeBlock::clearDebuggerRequests):

• CodeBlock::m_debuggerRequests is a union of m_numBreakpoints and the new m_steppingMode. The debugger can add/remove breakpoints to the CodeBlock as well as set the stepping mode. By having m_debuggerRequests as a union of the 2 bit fields, the op_debug code can now check if any of the 2 requests made on the CodeBlock is still in effect just by testing a single int.

• debugger/Debugger.cpp:

(JSC::Debugger::Debugger):
(JSC::Debugger::detach):

• This was bug from before where I forgot to clear the CodeBlock breakpoints before detaching. We now take care of it by clearing all debugger requests made to the CodeBlock.

(JSC::Debugger::SetSteppingModeFunctor::SetSteppingModeFunctor):
(JSC::Debugger::SetSteppingModeFunctor::operator()):
(JSC::Debugger::setSteppingMode):
(JSC::Debugger::ClearCodeBlockDebuggerRequestsFunctor::ClearCodeBlockDebuggerRequestsFunctor):
(JSC::Debugger::ClearCodeBlockDebuggerRequestsFunctor::operator()):
(JSC::Debugger::clearBreakpoints):

(JSC::Debugger::ClearDebuggerRequestsFunctor::ClearDebuggerRequestsFunctor):
(JSC::Debugger::ClearDebuggerRequestsFunctor::operator()):
(JSC::Debugger::clearDebuggerRequests):

• We need a distinct clearDebuggerRequests() from clearBreakpoints() because:
  1. When we detach a globalObject, we only want to clear the debugger requests in CodeBlocks from that global.
  2. Clearing the debugger requests in the CodeBlocks is not the same as clearing the breakpoints. The breakpoints are still in effect for the next time a globalObject is attached, or for other globalObjects that are still attached.

(JSC::Debugger::setPauseOnNextStatement):
(JSC::Debugger::breakProgram):
(JSC::Debugger::stepIntoStatement):
(JSC::Debugger::updateCallFrameAndPauseIfNeeded):
(JSC::Debugger::pauseIfNeeded):
(JSC::Debugger::exception):
(JSC::Debugger::willExecuteProgram):
(JSC::Debugger::didReachBreakpoint):

• debugger/Debugger.h:
• We're always going to support the debugger. So, there's no longer a need to check ENABLE(JAVASCRIPT_DEBUGGER). Removed the unneeded code.

• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• interpreter/Interpreter.cpp:

(JSC::Interpreter::debug):

• jit/JITOpcodes.cpp:

(JSC::JIT::emit_op_debug):

• jit/JITOpcodes32_64.cpp:

(JSC::JIT::emit_op_debug):

• llint/LowLevelInterpreter.asm:
• runtime/JSGlobalObject.h:

(JSC::JSGlobalObject::setDebugger):

Location:

trunk/Source/JavaScriptCore/jit

Files:

• JITOpcodes.cpp (modified) (1 diff)
• JITOpcodes32_64.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/jit/JITOpcodes.cpp

@@ -711 +711 @@
 void JIT::emit_op_debug(Instruction* currentInstruction)
 {
-#if ENABLE(DEBUG_WITH_BREAKPOINT)
-    UNUSED_PARAM(currentInstruction);
-    breakpoint();
-#elif ENABLE(JAVASCRIPT_DEBUGGER)
-    JSGlobalObject* globalObject = codeBlock()->globalObject();
-    char* debuggerAddress = reinterpret_cast<char*>(globalObject) + JSGlobalObject::debuggerOffset();
-    Jump noDebugger = branchTestPtr(Zero, AbsoluteAddress(debuggerAddress));
-
-    Debugger* debugger = globalObject->debugger();
-    char* shouldPauseAddress = reinterpret_cast<char*>(debugger) + Debugger::shouldPauseOffset();
-    Jump callbackNeeded = branchTest8(NonZero, AbsoluteAddress(shouldPauseAddress));
-
-    char* numBreakpointsAddress = reinterpret_cast<char*>(codeBlock()) + CodeBlock::numBreakpointsOffset();
-    load32(numBreakpointsAddress, regT0);
-    Jump noBreakpointSet = branchTest32(Zero, regT0);
-
-    callbackNeeded.link(this);
+    load32(codeBlock()->debuggerRequestsAddress(), regT0);
+    Jump noDebuggerRequests = branchTest32(Zero, regT0);
     callOperation(operationDebug, currentInstruction[1].u.operand);
-
-    noBreakpointSet.link(this);
-    noDebugger.link(this);
-#else
-    UNUSED_PARAM(currentInstruction);
-#endif
+    noDebuggerRequests.link(this);
 }
 

trunk/Source/JavaScriptCore/jit/JITOpcodes32_64.cpp

@@ -993 +993 @@
 void JIT::emit_op_debug(Instruction* currentInstruction)
 {
-#if ENABLE(DEBUG_WITH_BREAKPOINT)
-    UNUSED_PARAM(currentInstruction);
-    breakpoint();
-#elif ENABLE(JAVASCRIPT_DEBUGGER)
-    JSGlobalObject* globalObject = codeBlock()->globalObject();
-    char* debuggerAddress = reinterpret_cast<char*>(globalObject) + JSGlobalObject::debuggerOffset();
-    loadPtr(debuggerAddress, regT0);
-    Jump noDebugger = branchTestPtr(Zero, regT0);
-
-    Debugger* debugger = globalObject->debugger();
-    char* shouldPauseAddress = reinterpret_cast<char*>(debugger) + Debugger::shouldPauseOffset();
-    Jump callbackNeeded = branchTest8(NonZero, AbsoluteAddress(shouldPauseAddress));
-
-    char* numBreakpointsAddress = reinterpret_cast<char*>(codeBlock()) + CodeBlock::numBreakpointsOffset();
-    load32(numBreakpointsAddress, regT0);
-    Jump noBreakpointSet = branchTest32(Zero, regT0);
-
-    callbackNeeded.link(this);
+    load32(codeBlock()->debuggerRequestsAddress(), regT0);
+    Jump noDebuggerRequests = branchTest32(Zero, regT0);
     callOperation(operationDebug, currentInstruction[1].u.operand);
-
-    noBreakpointSet.link(this);
-    noDebugger.link(this);
-#else
-    UNUSED_PARAM(currentInstruction);
-#endif
+    noDebuggerRequests.link(this);
 }