LibJS: Forward a string aproximation of the CallExpression to Call Ops

This gives us better debug output when analysing calls to `undefined`
and also fixes multiple test-js cases expecting an
`(evaluated from $Expression)` in the error message.

This also refactors out the generation of that string, to avoid code
duplication with the AST interpreter.

Userland/Libraries/LibJS/AST.cpp

@@ -404,21 +404,25 @@ Completion NewExpression::execute(Interpreter& interpreter) const
     return Value { TRY(construct(vm, constructor.as_function(), move(arg_list))) };
 }
 
+Optional<String> CallExpression::expression_string() const
+{
+    if (is<Identifier>(*m_callee))
+        return static_cast<Identifier const&>(*m_callee).string();
+
+    if (is<MemberExpression>(*m_callee))
+        return static_cast<MemberExpression const&>(*m_callee).to_string_approximation();
+
+    return {};
+}
+
 Completion CallExpression::throw_type_error_for_callee(Interpreter& interpreter, Value callee_value, StringView call_type) const
 {
     auto& vm = interpreter.vm();
 
-    if (is<Identifier>(*m_callee) || is<MemberExpression>(*m_callee)) {
-        String expression_string;
-        if (is<Identifier>(*m_callee)) {
-            expression_string = static_cast<Identifier const&>(*m_callee).string();
-        } else {
-            expression_string = static_cast<MemberExpression const&>(*m_callee).to_string_approximation();
-        }
-        return vm.throw_completion<TypeError>(ErrorType::IsNotAEvaluatedFrom, callee_value.to_string_without_side_effects(), call_type, expression_string);
-    } else {
+    if (auto expression_string = this->expression_string(); expression_string.has_value())
+        return vm.throw_completion<TypeError>(ErrorType::IsNotAEvaluatedFrom, callee_value.to_string_without_side_effects(), call_type, expression_string.release_value());
+
     return vm.throw_completion<TypeError>(ErrorType::IsNotA, callee_value.to_string_without_side_effects(), call_type);
-    }
 }
 
 // 13.3.6.1 Runtime Semantics: Evaluation, https://tc39.es/ecma262/#sec-function-calls-runtime-semantics-evaluation

Userland/Libraries/LibJS/AST.h

@@ -1477,6 +1477,7 @@ protected:
     virtual bool is_call_expression() const override { return true; }
 
     Completion throw_type_error_for_callee(Interpreter&, Value callee_value, StringView call_type) const;
+    Optional<String> expression_string() const;
 
     NonnullRefPtr<Expression> m_callee;
     Vector<Argument> const m_arguments;

Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp

@@ -1548,7 +1548,12 @@ Bytecode::CodeGenerationErrorOr<void> CallExpression::generate_bytecode(Bytecode
         call_type = Bytecode::Op::Call::CallType::Call;
     }
 
-    generator.emit<Bytecode::Op::Call>(call_type, callee_reg, this_reg);
+    Optional<Bytecode::StringTableIndex> expression_string_index;
+    if (auto expression_string = this->expression_string(); expression_string.has_value())
+        expression_string_index = generator.intern_string(expression_string.release_value());
+
+    generator.emit<Bytecode::Op::Call>(call_type, callee_reg, this_reg, expression_string_index);
+
     return {};
 }
 

Userland/Libraries/LibJS/Bytecode/Op.cpp

@@ -584,6 +584,15 @@ static MarkedVector<Value> argument_list_evaluation(Bytecode::Interpreter& inter
     return argument_values;
 }
 
+Completion Call::throw_type_error_for_callee(Bytecode::Interpreter& interpreter, StringView callee_type) const
+{
+    auto callee = interpreter.reg(m_callee);
+    if (m_expression_string.has_value())
+        return interpreter.vm().throw_completion<TypeError>(ErrorType::IsNotAEvaluatedFrom, callee.to_string_without_side_effects(), callee_type, interpreter.current_executable().get_string(m_expression_string->value()));
+
+    return interpreter.vm().throw_completion<TypeError>(ErrorType::IsNotA, callee.to_string_without_side_effects(), callee_type);
+}
+
 ThrowCompletionOr<void> Call::execute_impl(Bytecode::Interpreter& interpreter) const
 {
     auto& vm = interpreter.vm();
@@ -591,10 +600,9 @@ ThrowCompletionOr<void> Call::execute_impl(Bytecode::Interpreter& interpreter) c
     auto callee = interpreter.reg(m_callee);
 
     if (m_type == CallType::Call && !callee.is_function())
-        return vm.throw_completion<TypeError>(ErrorType::IsNotA, callee.to_string_without_side_effects(), "function"sv);
-
+        return throw_type_error_for_callee(interpreter, "function"sv);
     if (m_type == CallType::Construct && !callee.is_constructor())
-        return vm.throw_completion<TypeError>(ErrorType::IsNotA, callee.to_string_without_side_effects(), "constructor"sv);
+        return throw_type_error_for_callee(interpreter, "constructor"sv);
 
     auto& function = callee.as_function();
 
@@ -1138,8 +1146,11 @@ String JumpUndefined::to_string_impl(Bytecode::Executable const&) const
     return String::formatted("JumpUndefined undefined:{} not undefined:{}", true_string, false_string);
 }
 
-String Call::to_string_impl(Bytecode::Executable const&) const
+String Call::to_string_impl(Bytecode::Executable const& executable) const
 {
+    if (m_expression_string.has_value())
+        return String::formatted("Call callee:{}, this:{}, arguments:[...acc] ({})", m_callee, m_this_value, executable.get_string(m_expression_string.value()));
+
     return String::formatted("Call callee:{}, this:{}, arguments:[...acc]", m_callee, m_this_value);
 }
 

Userland/Libraries/LibJS/Bytecode/Op.h

@@ -604,11 +604,12 @@ public:
         Construct,
     };
 
-    Call(CallType type, Register callee, Register this_value)
+    Call(CallType type, Register callee, Register this_value, Optional<StringTableIndex> expression_string = {})
         : Instruction(Type::Call)
         , m_callee(callee)
         , m_this_value(this_value)
         , m_type(type)
+        , m_expression_string(expression_string)
     {
     }
 
@@ -616,10 +617,13 @@ public:
     String to_string_impl(Bytecode::Executable const&) const;
     void replace_references_impl(BasicBlock const&, BasicBlock const&) { }
 
+    Completion throw_type_error_for_callee(Bytecode::Interpreter&, StringView callee_type) const;
+
 private:
     Register m_callee;
     Register m_this_value;
     CallType m_type;
+    Optional<StringTableIndex> m_expression_string;
 };
 
 // NOTE: This instruction is variable-width depending on the number of arguments!