Changeset 172717 in webkit for trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

Timestamp:

Aug 18, 2014, 12:11:41 PM (11 years ago)

Author:

[email protected]

Message:

The parser should generate AST nodes the var declarations with no initializers
​https://bugs.webkit.org/show_bug.cgi?id=135545

Patch by Saam Barati <​[email protected]> on 2014-08-18
Reviewed by Geoffrey Garen.

Currently, JSC's parser ignores variable declarations
that have no assignment initializer value because all
variables are implicitly assigned to undefined. But,
type profiling needs an AST node to be generated for these
empty variable declarations because it needs to be able to
profile their text locations and to see that their type
is undefined.

• bytecompiler/NodesCodegen.cpp:

(JSC::EmptyVarExpression::emitBytecode):

• parser/ASTBuilder.h:

(JSC::ASTBuilder::createVarStatement):
(JSC::ASTBuilder::createEmptyVarExpression):

• parser/NodeConstructors.h:

(JSC::EmptyVarExpression::EmptyVarExpression):

• parser/Nodes.h:
• parser/Parser.cpp:

(JSC::Parser<LexerType>::parseVarDeclarationList):

• parser/SyntaxChecker.h:

(JSC::SyntaxChecker::createEmptyVarExpression):

File:

• trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

@@ -1783 +1783 @@
 }
 
+// ------------------------------ EmptyVarExpression ----------------------------
+
+RegisterID* EmptyVarExpression::emitBytecode(BytecodeGenerator& generator, RegisterID*)
+{
+    if (!generator.isProfilingTypesWithHighFidelity())
+        return nullptr;
+
+    if (Local local = generator.local(m_ident))
+        generator.emitProfileTypesWithHighFidelity(local.get(), ProfileTypesBytecodeHasGlobalID, nullptr);
+    else {
+        RefPtr<RegisterID> scope = generator.emitResolveScope(generator.newTemporary(), m_ident);
+        RefPtr<RegisterID> value = generator.emitGetFromScope(generator.newTemporary(), scope.get(), m_ident, DoNotThrowIfNotFound);
+        generator.emitProfileTypesWithHighFidelity(value.get(), ProfileTypesBytecodeGetFromScope, &m_ident);
+    }
+
+    generator.emitHighFidelityTypeProfilingExpressionInfo(position(), JSTextPosition(-1, position().offset + m_ident.length(), -1));
+
+    // It's safe to return null here because this node will always be a child node of VarStatementNode which ignores our return value.
+    return nullptr;
+}
+
 // ------------------------------ IfElseNode ---------------------------------------