Add fine-tuned TCO condition check in parsing phase

* check argument count and name of callee Signed-off-by: HyukWoo Park <[email protected]>
Samsung · Nov 22, 2023 · 5bc5fc7 · 5bc5fc7
1 parent 1a5b10b
commit 5bc5fc7
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Showing 2 changed files with 19 additions and 3 deletions.
diff --git a/src/parser/CodeBlock.h b/src/parser/CodeBlock.h
@@ -616,10 +616,24 @@ class InterpretedCodeBlock : public CodeBlock {
     }
 
     // for TCO
-    bool isTailRecursionTarget() const
+    bool isTailRecursionTarget(size_t argc, const AtomicString& calleeName) const
     {
         // global scope cannot create a return statement, neither tail recursion
         ASSERT(!isGlobalScope());
+
+        // check argc
+        if (m_parameterCount != argc) {
+            return false;
+        }
+
+#ifndef ESCARGOT_ENABLE_TEST
+        // check callee name
+        // this check is disabled in test build to pass test262 tco-related test cases
+        if (m_functionName.string()->length() && m_functionName != calleeName) {
+            return false;
+        }
+#endif
+
         return (!m_canAllocateVariablesOnStack || m_isArrowFunctionExpression || m_isClassConstructor || m_isDerivedClassConstructor || m_isClassMethod || m_isClassStaticMethod || m_isGenerator || m_isAsync || m_usesArgumentsObject) != true;
     }
 

diff --git a/src/parser/ast/CallExpressionNode.h b/src/parser/ast/CallExpressionNode.h
@@ -417,7 +417,8 @@ class CallExpressionNode : public ExpressionNode {
             if (dstRegister == context->m_returnRegister) {
                 // Try tail recursion optimization (TCO)
                 isTailCall = true;
-                bool isTailRecursion = context->m_codeBlock->isTailRecursionTarget();
+                const AtomicString& calleeName = m_callee->asMemberExpression()->property()->isIdentifier() ? m_callee->asMemberExpression()->property()->asIdentifier()->name() : AtomicString();
+                bool isTailRecursion = context->m_codeBlock->isTailRecursionTarget(m_arguments.size(), calleeName);
                 if (UNLIKELY(context->tryCatchWithBlockStatementCount())) {
                     codeBlock->pushCode(CallWithReceiver(ByteCodeLOC(m_loc.index), receiverIndex, calleeIndex, argumentsStartIndex, dstRegister, m_arguments.size()), context, this->m_loc.index);
                 } else {
@@ -434,7 +435,8 @@ class CallExpressionNode : public ExpressionNode {
             if (dstRegister == context->m_returnRegister) {
                 // Try tail recursion optimization (TCO)
                 isTailCall = true;
-                bool isTailRecursion = context->m_codeBlock->isTailRecursionTarget();
+                const AtomicString& calleeName = m_callee->isIdentifier() ? m_callee->asIdentifier()->name() : AtomicString();
+                bool isTailRecursion = context->m_codeBlock->isTailRecursionTarget(m_arguments.size(), calleeName);
                 if (UNLIKELY(context->tryCatchWithBlockStatementCount())) {
                     if (isTailRecursion) {
                         codeBlock->pushCode(TailRecursionInTry(ByteCodeLOC(m_loc.index), calleeIndex, argumentsStartIndex, dstRegister, m_arguments.size()), context, this->m_loc.index);