Changeset 180595 in webkit for trunk/Source/JavaScriptCore/dfg/DFGJITCode.cpp

Timestamp:

Feb 24, 2015, 4:41:35 PM (10 years ago)

Author:

[email protected]

Message:

Use "this" instead of "callee" to get the constructor
​https://bugs.webkit.org/show_bug.cgi?id=141019

Reviewed by Filip Pizlo.

This patch uses "this" register to pass the constructor (newTarget) to op_create_this from
op_construct or op_construct_varargs. This will allow future patches that implement ES6 class
to pass in the most derived class' constructor through "this" argument.

BytecodeGenerator's emitConstruct and emitConstructVarargs now passes thisRegister like
regular calls and emitCreateThis passes in this register to op_create_this as constructor.

The rest of the code change removes the code for special casing "this" register not being used
in call to construct.

• bytecode/BytecodeUseDef.h:

(JSC::computeUsesForBytecodeOffset):

• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::emitCreateThis):
(JSC::BytecodeGenerator::emitConstructVarargs):
(JSC::BytecodeGenerator::emitConstruct):

• bytecompiler/BytecodeGenerator.h:
• bytecompiler/NodesCodegen.cpp:

(JSC::NewExprNode::emitBytecode):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::addCallWithoutSettingResult):
(JSC::DFG::ByteCodeParser::handleVarargsCall):
(JSC::DFG::ByteCodeParser::emitArgumentPhantoms):
(JSC::DFG::ByteCodeParser::attemptToInlineCall):
(JSC::DFG::ByteCodeParser::handleInlining):
(JSC::DFG::ByteCodeParser::handleConstantInternalFunction):
(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGJITCode.cpp:

(JSC::DFG::JITCode::reconstruct):

• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::emitCall):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::emitCall):

• ftl/FTLJSCallVarargs.cpp:

(JSC::FTL::JSCallVarargs::emit):

• ftl/FTLLowerDFGToLLVM.cpp:

(JSC::FTL::LowerDFGToLLVM::compileNativeCallOrConstruct):
(JSC::FTL::LowerDFGToLLVM::compileCallOrConstruct):
(JSC::FTL::LowerDFGToLLVM::compileCallOrConstructVarargs):

• interpreter/Interpreter.cpp:

(JSC::Interpreter::executeConstruct):

• jit/JITOperations.cpp:

File:

• trunk/Source/JavaScriptCore/dfg/DFGJITCode.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/dfg/DFGJITCode.cpp

@@ -83 +83 @@
     
     result = Operands<JSValue>(OperandsLike, recoveries);
-    for (size_t i = result.size(); i--;) {
-        int operand = result.operandForIndex(i);
-        
-        if (codeOrigin == CodeOrigin(0)
-            && operandIsArgument(operand)
-            && !VirtualRegister(operand).toArgument()
-            && codeBlock->codeType() == FunctionCode
-            && codeBlock->specializationKind() == CodeForConstruct) {
-            // Ugh. If we're in a constructor, the 'this' argument may hold garbage. It will
-            // also never be used. It doesn't matter what we put into the value for this,
-            // but it has to be an actual value that can be grokked by subsequent DFG passes,
-            // so we sanitize it here by turning it into Undefined.
-            result[i] = jsUndefined();
-            continue;
-        }
-        
+    for (size_t i = result.size(); i--;)
         result[i] = recoveries[i].recover(exec);
-    }
 }