Changeset 39255 in webkit for trunk/JavaScriptCore/bytecode/CodeBlock.cpp

Timestamp:

Dec 12, 2008, 2:48:53 PM (16 years ago)

Author:

[email protected]

Message:

2008-12-12 Cameron Zwarich <​[email protected]>

Reviewed by Sam Weinig.

Bug 22828: Do not inspect bytecode instruction stream for op_get_by_id exception information
<​https://bugs.webkit.org/show_bug.cgi?id=22828>

In order to remove the bytecode instruction stream after generating
native code, all inspection of bytecode instructions at runtime must
be removed. One particular instance of this is the special handling of
exceptions thrown by the op_get_by_id emitted directly before an
op_construct or an op_instanceof. This patch moves that information to
an auxiliary data structure in CodeBlock.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::getByIdExceptionInfoForBytecodeOffset):
• bytecode/CodeBlock.h: (JSC::CodeBlock::addGetByIdExceptionInfo):
• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::emitConstruct):
• bytecompiler/BytecodeGenerator.h: (JSC::BytecodeGenerator::emitGetByIdExceptionInfo):
• parser/Nodes.cpp: (JSC::InstanceOfNode::emitBytecode):
• runtime/ExceptionHelpers.cpp: (JSC::createNotAnObjectError):

File:

• trunk/JavaScriptCore/bytecode/CodeBlock.cpp (modified) (1 diff)

trunk/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -1407 +1407 @@
 }
 
+bool CodeBlock::getByIdExceptionInfoForBytecodeOffset(unsigned bytecodeOffset, OpcodeID& opcodeID)
+{
+    ASSERT(bytecodeOffset < m_instructions.size());
+
+    if (!m_getByIdExceptionInfo.size())
+        return false;
+
+    int low = 0;
+    int high = m_getByIdExceptionInfo.size();
+    while (low < high) {
+        int mid = low + (high - low) / 2;
+        if (m_getByIdExceptionInfo[mid].bytecodeOffset <= bytecodeOffset)
+            low = mid + 1;
+        else
+            high = mid;
+    }
+
+    if (!low)
+        return false;
+
+    opcodeID = m_getByIdExceptionInfo[low - 1].isOpConstruct ? op_construct : op_instanceof;
+    return true;
+}
+
 void CodeBlock::shrinkToFit()
 {