Changeset 127774 in webkit for trunk/Source/JavaScriptCore/bytecompiler

Timestamp:

Sep 6, 2012, 12:45:35 PM (13 years ago)

Author:

[email protected]

Message:

Rolled out <​http://trac.webkit.org/changeset/127698> because it broke
fast/dom/HTMLScriptElement/script-reexecution-pretty-diff.html

Named functions should not allocate scope objects for their names
​https://bugs.webkit.org/show_bug.cgi?id=95659

Reviewed by Oliver Hunt.

Location:

trunk/Source/JavaScriptCore/bytecompiler

Files:

• BytecodeGenerator.cpp (modified) (11 diffs)
• BytecodeGenerator.h (modified) (4 diffs)

trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

@@ -34 +34 @@
 #include "BatchedTransitionOptimizer.h"
 #include "Comment.h"
-#include "Interpreter.h"
 #include "JSActivation.h"
 #include "JSFunction.h"
-#include "JSNameScope.h"
+#include "Interpreter.h"
 #include "LowLevelInterpreter.h"
+
 #include "StrongInlines.h"
 #include <wtf/text/WTFString.h>
@@ -325 +325 @@
             globalObject->removeDirect(*m_globalData, function->ident()); // Newly declared functions overwrite existing properties.
         
-        JSValue value = JSFunction::create(exec, FunctionExecutable::create(*m_globalData, function), scope);
+        JSValue value = JSFunction::create(exec, makeFunction(exec, function), scope);
         int index = addGlobalVar(
             function->ident(), IsVariable,
@@ -420 +420 @@
     }
 
-    RegisterID* calleeRegister = resolveCallee(functionBody); // May push to the scope chain and/or add a captured var.
-
     const DeclarationStacks::FunctionStack& functionStack = functionBody->functionStack();
     const DeclarationStacks::VarStack& varStack = functionBody->varStack();
@@ -459 +457 @@
 
     codeBlock->m_numCapturedVars = codeBlock->m_numVars;
-
     m_firstLazyFunction = codeBlock->m_numVars;
     for (size_t i = 0; i < functionStack.size(); ++i) {
@@ -500 +497 @@
 
     preserveLastVar();
-
-    // We declare the callee's name last because it should lose to a var, function, and/or parameter declaration.
-    addCallee(functionBody, calleeRegister);
 
     if (isConstructor()) {
@@ -556 +550 @@
     const DeclarationStacks::FunctionStack& functionStack = evalNode->functionStack();
     for (size_t i = 0; i < functionStack.size(); ++i)
-        m_codeBlock->addFunctionDecl(FunctionExecutable::create(*m_globalData, functionStack[i]));
+        m_codeBlock->addFunctionDecl(makeFunction(m_globalData, functionStack[i]));
 
     const DeclarationStacks::VarStack& varStack = evalNode->varStack();
@@ -579 +573 @@
     instructions().append(reg->index());
     return reg;
-}
-
-RegisterID* BytecodeGenerator::resolveCallee(FunctionBodyNode* functionBodyNode)
-{
-    if (functionBodyNode->ident().isNull())
-        return 0;
-
-    m_calleeRegister.setIndex(RegisterFile::Callee);
-
-    // If non-strict eval is in play, we use a separate object in the scope chain for the callee's name.
-    if ((m_codeBlock->usesEval() && !m_codeBlock->isStrictMode()) || m_shouldEmitDebugHooks) {
-        emitOpcode(op_push_name_scope);
-        instructions().append(addConstant(functionBodyNode->ident()));
-        instructions().append(m_calleeRegister.index());
-        instructions().append(ReadOnly | DontDelete);
-
-        // Put a mirror object in compilation scope, so compile-time variable resolution sees the property name we'll see at runtime.
-        m_scope.set(*globalData(),
-            JSNameScope::create(
-                m_scope->globalObject()->globalExec(),
-                functionBodyNode->ident(),
-                jsUndefined(),
-                ReadOnly | DontDelete,
-                m_scope.get()
-            )
-        );
-        return 0;
-    }
-
-    if (!functionBodyNode->captures(functionBodyNode->ident()))
-        return &m_calleeRegister;
-
-    // Move the callee into the captured section of the stack.
-    return emitMove(addVar(), &m_calleeRegister);
-}
-
-void BytecodeGenerator::addCallee(FunctionBodyNode* functionBodyNode, RegisterID* calleeRegister)
-{
-    if (functionBodyNode->ident().isNull())
-        return;
-
-    // If non-strict eval is in play, we use a separate object in the scope chain for the callee's name.
-    if ((m_codeBlock->usesEval() && !m_codeBlock->isStrictMode()) || m_shouldEmitDebugHooks)
-        return;
-
-    ASSERT(calleeRegister);
-    symbolTable().add(functionBodyNode->ident().impl(), SymbolTableEntry(calleeRegister->index(), ReadOnly));
 }
 
@@ -1884 +1831 @@
 RegisterID* BytecodeGenerator::emitNewFunction(RegisterID* dst, FunctionBodyNode* function)
 {
-    return emitNewFunctionInternal(dst, m_codeBlock->addFunctionDecl(FunctionExecutable::create(*m_globalData, function)), false);
+    return emitNewFunctionInternal(dst, m_codeBlock->addFunctionDecl(makeFunction(m_globalData, function)), false);
 }
 
@@ -1891 +1838 @@
     FunctionOffsetMap::AddResult ptr = m_functionOffsets.add(function, 0);
     if (ptr.isNewEntry)
-        ptr.iterator->second = m_codeBlock->addFunctionDecl(FunctionExecutable::create(*m_globalData, function));
+        ptr.iterator->second = m_codeBlock->addFunctionDecl(makeFunction(m_globalData, function));
     return emitNewFunctionInternal(dst, ptr.iterator->second, true);
 }
@@ -1916 +1863 @@
 {
     FunctionBodyNode* function = n->body();
-    unsigned index = m_codeBlock->addFunctionExpr(FunctionExecutable::create(*m_globalData, function));
+    unsigned index = m_codeBlock->addFunctionExpr(makeFunction(m_globalData, function));
     
     createActivationIfNecessary();
@@ -2653 +2600 @@
         return;
 
-    RefPtr<RegisterID> error = emitLoad(newTemporary(), JSValue(createTypeError(scope()->globalObject()->globalExec(), StrictModeReadonlyPropertyWriteError)));
+    RefPtr<RegisterID> error = emitLoad(newTemporary(), createTypeError(scope()->globalObject()->globalExec(), StrictModeReadonlyPropertyWriteError));
     emitThrow(error.get());
 }

trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h

@@ -618 +618 @@
 
         void addParameter(const Identifier&, int parameterIndex);
-        RegisterID* resolveCallee(FunctionBodyNode*);
-        void addCallee(FunctionBodyNode*, RegisterID*);
-
+        
         void preserveLastVar();
         bool shouldAvoidResolveGlobal();
@@ -628 +626 @@
             if (index >= 0)
                 return m_calleeRegisters[index];
-
-            if (index == RegisterFile::Callee)
-                return m_calleeRegister;
 
             ASSERT(m_parameters.size());
@@ -642 +637 @@
         unsigned addConstantBuffer(unsigned length);
         
+        FunctionExecutable* makeFunction(ExecState* exec, FunctionBodyNode* body)
+        {
+            return FunctionExecutable::create(exec, body->ident(), body->inferredName(), body->source(), body->usesArguments(), body->parameters(), body->isStrictMode(), body->lineNo(), body->lastLine());
+        }
+
+        FunctionExecutable* makeFunction(JSGlobalData* globalData, FunctionBodyNode* body)
+        {
+            return FunctionExecutable::create(*globalData, body->ident(), body->inferredName(), body->source(), body->usesArguments(), body->parameters(), body->isStrictMode(), body->lineNo(), body->lastLine());
+        }
+
         JSString* addStringConstant(const Identifier&);
 
@@ -712 +717 @@
         RegisterID m_ignoredResultRegister;
         RegisterID m_thisRegister;
-        RegisterID m_calleeRegister;
         RegisterID* m_activationRegister;
         SegmentedVector<RegisterID, 32> m_constantPoolRegisters;