Parser / PreParser: Simplify error message arguments.

src/parser.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "v8.h"
 
 #include "api.h"
 #include "ast.h"
 #include "bootstrapper.h"
 #include "char-predicates-inl.h"
@@ skipping 282 matching lines @@
   return Read(PreparseDataConstants::kIsReferenceErrorPos);
 }
 
 
 const char* ScriptData::BuildMessage() const {
   unsigned* start = ReadAddress(PreparseDataConstants::kMessageTextPos);
   return ReadString(start, NULL);
 }
 
 
-Vector<const char*> ScriptData::BuildArgs() const {
+const char* ScriptData::BuildArg() const {
   int arg_count = Read(PreparseDataConstants::kMessageArgCountPos);
-  const char** array = NewArray<const char*>(arg_count);
+  ASSERT(arg_count == 0 || arg_count == 1);
+  if (arg_count == 0) {
+    return NULL;
+  }
   // Position after text found by skipping past length field and
   // length field content words.
   int pos = PreparseDataConstants::kMessageTextPos + 1
       + Read(PreparseDataConstants::kMessageTextPos);
-  for (int i = 0; i < arg_count; i++) {
-    int count = 0;
-    array[i] = ReadString(ReadAddress(pos), &count);
-    pos += count + 1;
-  }
-  return Vector<const char*>(array, arg_count);
+  int count = 0;
+  return ReadString(ReadAddress(pos), &count);
 }
 
 
 unsigned ScriptData::Read(int position) const {
   return store_[PreparseDataConstants::kHeaderSize + position];
 }
 
 
 unsigned* ScriptData::ReadAddress(int position) const {
   return &store_[PreparseDataConstants::kHeaderSize + position];
@@ skipping 290 matching lines @@
   args->Add(parser_->factory()->NewLiteral(type, pos), zone);
   args->Add(parser_->factory()->NewLiteral(array, pos), zone);
   CallRuntime* call_constructor =
       parser_->factory()->NewCallRuntime(constructor, NULL, args, pos);
   return parser_->factory()->NewThrow(call_constructor, pos);
 }
 
 
 void ParserTraits::ReportMessageAt(Scanner::Location source_location,
                                    const char* message,
-                                   Vector<const char*> args,
+                                   const char* arg,
                                    bool is_reference_error) {
   if (parser_->stack_overflow()) {
     // Suppress the error message (syntax error or such) in the presence of a
     // stack overflow. The isolate allows only one pending exception at at time
     // and we want to report the stack overflow later.
     return;
   }
   MessageLocation location(parser_->script_,
                            source_location.beg_pos,
                            source_location.end_pos);
   Factory* factory = parser_->isolate()->factory();
-  Handle<FixedArray> elements = factory->NewFixedArray(args.length());
-  for (int i = 0; i < args.length(); i++) {
+  Handle<FixedArray> elements = factory->NewFixedArray(arg == NULL ? 0 : 1);
+  if (arg != NULL) {
     Handle<String> arg_string =
-        factory->NewStringFromUtf8(CStrVector(args[i])).ToHandleChecked();
-    elements->set(i, *arg_string);
+        factory->NewStringFromUtf8(CStrVector(arg)).ToHandleChecked();
+    elements->set(0, *arg_string);
   }
   Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
   Handle<Object> result = is_reference_error
       ? factory->NewReferenceError(message, array)
       : factory->NewSyntaxError(message, array);
   parser_->isolate()->Throw(*result, &location);
 }
 
 
 void ParserTraits::ReportMessage(const char* message,
-                                 Vector<Handle<String> > args,
+                                 MaybeHandle<String> arg,
                                  bool is_reference_error) {
   Scanner::Location source_location = parser_->scanner()->location();
-  ReportMessageAt(source_location, message, args, is_reference_error);
+  ReportMessageAt(source_location, message, arg, is_reference_error);
 }
 
 
 void ParserTraits::ReportMessageAt(Scanner::Location source_location,
                                    const char* message,
-                                   Vector<Handle<String> > args,
+                                   MaybeHandle<String> arg,
                                    bool is_reference_error) {
   if (parser_->stack_overflow()) {
     // Suppress the error message (syntax error or such) in the presence of a
     // stack overflow. The isolate allows only one pending exception at at time
     // and we want to report the stack overflow later.
     return;
   }
   MessageLocation location(parser_->script_,
                            source_location.beg_pos,
                            source_location.end_pos);
   Factory* factory = parser_->isolate()->factory();
-  Handle<FixedArray> elements = factory->NewFixedArray(args.length());
-  for (int i = 0; i < args.length(); i++) {
-    elements->set(i, *args[i]);
+  Handle<FixedArray> elements = factory->NewFixedArray(arg.is_null() ? 0 : 1);
+  if (!arg.is_null()) {
+    elements->set(0, *(arg.ToHandleChecked()));
   }
   Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
   Handle<Object> result = is_reference_error
       ? factory->NewReferenceError(message, array)
       : factory->NewSyntaxError(message, array);
   parser_->isolate()->Throw(*result, &location);
 }
 
 
 Handle<String> ParserTraits::GetSymbol(Scanner* scanner) {
@@ skipping 224 matching lines @@
 
     if (ok && allow_harmony_scoping() && strict_mode() == STRICT) {
       CheckConflictingVarDeclarations(scope_, &ok);
     }
 
     if (ok && info->parse_restriction() == ONLY_SINGLE_FUNCTION_LITERAL) {
       if (body->length() != 1 ||
           !body->at(0)->IsExpressionStatement() ||
           !body->at(0)->AsExpressionStatement()->
               expression()->IsFunctionLiteral()) {
-        ReportMessage("single_function_literal", Vector<const char*>::empty());
+        ReportMessage("single_function_literal");
         ok = false;
       }
     }
 
     if (ok) {
       result = factory()->NewFunctionLiteral(
           no_name,
           scope_,
           body,
           function_state.materialized_literal_count(),
@@ skipping 337 matching lines @@
 
   Expect(Token::RBRACE, CHECK_OK);
   scope->set_end_position(scanner()->location().end_pos);
   body->set_scope(scope);
 
   // Check that all exports are bound.
   Interface* interface = scope->interface();
   for (Interface::Iterator it = interface->iterator();
        !it.done(); it.Advance()) {
     if (scope->LocalLookup(it.name()) == NULL) {
-      Handle<String> name(it.name());
-      ParserTraits::ReportMessage("module_export_undefined",
-                                  Vector<Handle<String> >(&name, 1));
+      ParserTraits::ReportMessage("module_export_undefined", it.name());
       *ok = false;
       return NULL;
     }
   }
 
   interface->MakeModule(ok);
   ASSERT(*ok);
   interface->Freeze(ok);
   ASSERT(*ok);
   return factory()->NewModuleLiteral(body, interface, pos);
@@ skipping 18 matching lines @@
     if (!*ok) {
 #ifdef DEBUG
       if (FLAG_print_interfaces) {
         PrintF("PATH TYPE ERROR at '%s'\n", name->ToAsciiArray());
         PrintF("result: ");
         result->interface()->Print();
         PrintF("member: ");
         member->interface()->Print();
       }
 #endif
-      ParserTraits::ReportMessage("invalid_module_path",
-                                  Vector<Handle<String> >(&name, 1));
+      ParserTraits::ReportMessage("invalid_module_path", name);
       return NULL;
     }
     result = member;
   }
 
   return result;
 }
 
 
 Module* Parser::ParseModuleVariable(bool* ok) {
@@ skipping 89 matching lines @@
     Interface* interface = Interface::NewUnknown(zone());
     module->interface()->Add(names[i], interface, zone(), ok);
     if (!*ok) {
 #ifdef DEBUG
       if (FLAG_print_interfaces) {
         PrintF("IMPORT TYPE ERROR at '%s'\n", names[i]->ToAsciiArray());
         PrintF("module: ");
         module->interface()->Print();
       }
 #endif
-      ParserTraits::ReportMessage("invalid_module_path",
-                                  Vector<Handle<String> >(&name, 1));
+      ParserTraits::ReportMessage("invalid_module_path", name);
       return NULL;
     }
     VariableProxy* proxy = NewUnresolved(names[i], LET, interface);
     Declaration* declaration =
         factory()->NewImportDeclaration(proxy, module, scope_, pos);
     Declare(declaration, true, CHECK_OK);
   }
 
   return block;
 }
@@ skipping 267 matching lines @@
       // the special case
       //
       // function () { let x; { var x; } }
       //
       // because the var declaration is hoisted to the function scope where 'x'
       // is already bound.
       ASSERT(IsDeclaredVariableMode(var->mode()));
       if (allow_harmony_scoping() && strict_mode() == STRICT) {
         // In harmony we treat re-declarations as early errors. See
         // ES5 16 for a definition of early errors.
-        SmartArrayPointer<char> c_string = name->ToCString(DISALLOW_NULLS);
-        const char* elms[1] = { c_string.get() };
-        Vector<const char*> args(elms, 1);
-        ReportMessage("var_redeclaration", args);
+        ParserTraits::ReportMessage("var_redeclaration", name);
         *ok = false;
         return;
       }
       Expression* expression = NewThrowTypeError(
           "var_redeclaration", name, declaration->position());
       declaration_scope->SetIllegalRedeclaration(expression);
     }
   }
 
   // We add a declaration node for every declaration. The compiler
@@ skipping 71 matching lines @@
       if (!ok) {
 #ifdef DEBUG
         if (FLAG_print_interfaces) {
           PrintF("DECLARE TYPE ERROR\n");
           PrintF("proxy: ");
           proxy->interface()->Print();
           PrintF("var: ");
           var->interface()->Print();
         }
 #endif
-        ParserTraits::ReportMessage("module_type_error",
-                                    Vector<Handle<String> >(&name, 1));
+        ParserTraits::ReportMessage("module_type_error", name);
       }
     }
   }
 }
 
 
 // Language extension which is only enabled for source files loaded
 // through the API's extension mechanism.  A native function
 // declaration is resolved by looking up the function through a
 // callback provided by the extension.
@@ skipping 198 matching lines @@
     switch (strict_mode()) {
       case SLOPPY:
         mode = CONST_LEGACY;
         init_op = Token::INIT_CONST_LEGACY;
         break;
       case STRICT:
         if (allow_harmony_scoping()) {
           if (var_context == kStatement) {
             // In strict mode 'const' declarations are only allowed in source
             // element positions.
-            ReportMessage("unprotected_const", Vector<const char*>::empty());
+            ReportMessage("unprotected_const");
             *ok = false;
             return NULL;
           }
           mode = CONST;
           init_op = Token::INIT_CONST;
         } else {
-          ReportMessage("strict_const", Vector<const char*>::empty());
+          ReportMessage("strict_const");
           *ok = false;
           return NULL;
         }
     }
     is_const = true;
     needs_init = true;
   } else if (peek() == Token::LET) {
     // ES6 Draft Rev4 section 12.2.1:
     //
     // LetDeclaration : let LetBindingList ;
     //
     // * It is a Syntax Error if the code that matches this production is not
     //   contained in extended code.
     //
     // TODO(rossberg): make 'let' a legal identifier in sloppy mode.
     if (!allow_harmony_scoping() || strict_mode() == SLOPPY) {
-      ReportMessage("illegal_let", Vector<const char*>::empty());
+      ReportMessage("illegal_let");
       *ok = false;
       return NULL;
     }
     Consume(Token::LET);
     if (var_context == kStatement) {
       // Let declarations are only allowed in source element positions.
-      ReportMessage("unprotected_let", Vector<const char*>::empty());
+      ReportMessage("unprotected_let");
       *ok = false;
       return NULL;
     }
     mode = LET;
     needs_init = true;
     init_op = Token::INIT_LET;
   } else {
     UNREACHABLE();  // by current callers
   }
 
@@ skipping 249 matching lines @@
     // Expression is a single identifier, and not, e.g., a parenthesized
     // identifier.
     VariableProxy* var = expr->AsVariableProxy();
     Handle<String> label = var->name();
     // TODO(1240780): We don't check for redeclaration of labels
     // during preparsing since keeping track of the set of active
     // labels requires nontrivial changes to the way scopes are
     // structured.  However, these are probably changes we want to
     // make later anyway so we should go back and fix this then.
     if (ContainsLabel(labels, label) || TargetStackContainsLabel(label)) {
-      SmartArrayPointer<char> c_string = label->ToCString(DISALLOW_NULLS);
-      const char* elms[1] = { c_string.get() };
-      Vector<const char*> args(elms, 1);
-      ReportMessage("label_redeclaration", args);
+      ParserTraits::ReportMessage("label_redeclaration", label);
       *ok = false;
       return NULL;
     }
     if (labels == NULL) {
       labels = new(zone()) ZoneStringList(4, zone());
     }
     labels->Add(label, zone());
     // Remove the "ghost" variable that turned out to be a label
     // from the top scope. This way, we don't try to resolve it
     // during the scope processing.
@@ skipping 64 matching lines @@
   if (!scanner()->HasAnyLineTerminatorBeforeNext() &&
       tok != Token::SEMICOLON && tok != Token::RBRACE && tok != Token::EOS) {
     // ECMA allows "eval" or "arguments" as labels even in strict mode.
     label = ParseIdentifier(kAllowEvalOrArguments, CHECK_OK);
   }
   IterationStatement* target = NULL;
   target = LookupContinueTarget(label, CHECK_OK);
   if (target == NULL) {
     // Illegal continue statement.
     const char* message = "illegal_continue";
-    Vector<Handle<String> > args;
     if (!label.is_null()) {
       message = "unknown_label";
-      args = Vector<Handle<String> >(&label, 1);
     }
-    ParserTraits::ReportMessageAt(scanner()->location(), message, args);
+    ParserTraits::ReportMessageAt(scanner()->location(), message, label);
     *ok = false;
     return NULL;
   }
   ExpectSemicolon(CHECK_OK);
   return factory()->NewContinueStatement(target, pos);
 }
 
 
 Statement* Parser::ParseBreakStatement(ZoneStringList* labels, bool* ok) {
   // BreakStatement ::
@@ skipping 12 matching lines @@
   // empty statements, e.g. 'l1: l2: l3: break l2;'
   if (!label.is_null() && ContainsLabel(labels, label)) {
     ExpectSemicolon(CHECK_OK);
     return factory()->NewEmptyStatement(pos);
   }
   BreakableStatement* target = NULL;
   target = LookupBreakTarget(label, CHECK_OK);
   if (target == NULL) {
     // Illegal break statement.
     const char* message = "illegal_break";
-    Vector<Handle<String> > args;
     if (!label.is_null()) {
       message = "unknown_label";
-      args = Vector<Handle<String> >(&label, 1);
     }
-    ParserTraits::ReportMessageAt(scanner()->location(), message, args);
+    ParserTraits::ReportMessageAt(scanner()->location(), message, label);
     *ok = false;
     return NULL;
   }
   ExpectSemicolon(CHECK_OK);
   return factory()->NewBreakStatement(target, pos);
 }
 
 
 Statement* Parser::ParseReturnStatement(bool* ok) {
   // ReturnStatement ::
@@ skipping 38 matching lines @@
 
 
 Statement* Parser::ParseWithStatement(ZoneStringList* labels, bool* ok) {
   // WithStatement ::
   //   'with' '(' Expression ')' Statement
 
   Expect(Token::WITH, CHECK_OK);
   int pos = position();
 
   if (strict_mode() == STRICT) {
-    ReportMessage("strict_mode_with", Vector<const char*>::empty());
+    ReportMessage("strict_mode_with");
     *ok = false;
     return NULL;
   }
 
   Expect(Token::LPAREN, CHECK_OK);
   Expression* expr = ParseExpression(true, CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
   scope_->DeclarationScope()->RecordWithStatement();
   Scope* with_scope = NewScope(scope_, WITH_SCOPE);
@@ skipping 12 matching lines @@
   //   'case' Expression ':' Statement*
   //   'default' ':' Statement*
 
   Expression* label = NULL;  // NULL expression indicates default case
   if (peek() == Token::CASE) {
     Expect(Token::CASE, CHECK_OK);
     label = ParseExpression(true, CHECK_OK);
   } else {
     Expect(Token::DEFAULT, CHECK_OK);
     if (*default_seen_ptr) {
-      ReportMessage("multiple_defaults_in_switch",
-                    Vector<const char*>::empty());
+      ReportMessage("multiple_defaults_in_switch");
       *ok = false;
       return NULL;
     }
     *default_seen_ptr = true;
   }
   Expect(Token::COLON, CHECK_OK);
   int pos = position();
   ZoneList<Statement*>* statements =
       new(zone()) ZoneList<Statement*>(5, zone());
   while (peek() != Token::CASE &&
@@ skipping 35 matching lines @@
 }
 
 
 Statement* Parser::ParseThrowStatement(bool* ok) {
   // ThrowStatement ::
   //   'throw' Expression ';'
 
   Expect(Token::THROW, CHECK_OK);
   int pos = position();
   if (scanner()->HasAnyLineTerminatorBeforeNext()) {
-    ReportMessage("newline_after_throw", Vector<const char*>::empty());
+    ReportMessage("newline_after_throw");
     *ok = false;
     return NULL;
   }
   Expression* exception = ParseExpression(true, CHECK_OK);
   ExpectSemicolon(CHECK_OK);
 
   return factory()->NewExpressionStatement(
       factory()->NewThrow(exception, pos), pos);
 }
 
@@ skipping 15 matching lines @@
 
   TargetCollector try_collector(zone());
   Block* try_block;
 
   { Target target(&this->target_stack_, &try_collector);
     try_block = ParseBlock(NULL, CHECK_OK);
   }
 
   Token::Value tok = peek();
   if (tok != Token::CATCH && tok != Token::FINALLY) {
-    ReportMessage("no_catch_or_finally", Vector<const char*>::empty());
+    ReportMessage("no_catch_or_finally");
     *ok = false;
     return NULL;
   }
 
   // If we can break out from the catch block and there is a finally block,
   // then we will need to collect escaping targets from the catch
   // block. Since we don't know yet if there will be a finally block, we
   // always collect the targets.
   TargetCollector catch_collector(zone());
   Scope* catch_scope = NULL;
@@ skipping 409 matching lines @@
   //   'debugger' ';'
 
   int pos = peek_position();
   Expect(Token::DEBUGGER, CHECK_OK);
   ExpectSemicolon(CHECK_OK);
   return factory()->NewDebuggerStatement(pos);
 }
 
 
 void Parser::ReportInvalidCachedData(Handle<String> name, bool* ok) {
-  SmartArrayPointer<char> name_string = name->ToCString(DISALLOW_NULLS);
-  const char* element[1] = { name_string.get() };
-  ReportMessage("invalid_cached_data_function",
-                Vector<const char*>(element, 1));
+  ParserTraits::ReportMessage("invalid_cached_data_function", name);
   *ok = false;
 }
 
 
 bool CompileTimeValue::IsCompileTimeValue(Expression* expression) {
   if (expression->AsLiteral() != NULL) return true;
   MaterializedLiteral* lit = expression->AsMaterializedLiteral();
   return lit != NULL && lit->is_simple();
 }
 
@@ skipping 349 matching lines @@
     SingletonLogger logger;
     PreParser::PreParseResult result =
         ParseLazyFunctionBodyWithPreParser(&logger);
     if (result == PreParser::kPreParseStackOverflow) {
       // Propagate stack overflow.
       set_stack_overflow();
       *ok = false;
       return;
     }
     if (logger.has_error()) {
-      const char* arg = logger.argument_opt();
-      Vector<const char*> args;
-      if (arg != NULL) {
-        args = Vector<const char*>(&arg, 1);
-      }
       ParserTraits::ReportMessageAt(
           Scanner::Location(logger.start(), logger.end()),
-          logger.message(), args, logger.is_reference_error());
+          logger.message(), logger.argument_opt(), logger.is_reference_error());
       *ok = false;
       return;
     }
     scope_->set_end_position(logger.end());
     Expect(Token::RBRACE, ok);
     if (!*ok) {
       return;
     }
     isolate()->counters()->total_preparse_skipped()->Increment(
         scope_->end_position() - function_block_pos);
@@ skipping 118 matching lines @@
   // Check for built-in IS_VAR macro.
   if (function != NULL &&
       function->intrinsic_type == Runtime::RUNTIME &&
       function->function_id == Runtime::kIS_VAR) {
     // %IS_VAR(x) evaluates to x if x is a variable,
     // leads to a parse error otherwise.  Could be implemented as an
     // inline function %_IS_VAR(x) to eliminate this special case.
     if (args->length() == 1 && args->at(0)->AsVariableProxy() != NULL) {
       return args->at(0);
     } else {
-      ReportMessage("not_isvar", Vector<const char*>::empty());
+      ReportMessage("not_isvar");
       *ok = false;
       return NULL;
     }
   }
 
   // Check that the expected number of arguments are being passed.
   if (function != NULL &&
       function->nargs != -1 &&
       function->nargs != args->length()) {
-    ReportMessage("illegal_access", Vector<const char*>::empty());
+    ReportMessage("illegal_access");
     *ok = false;
     return NULL;
   }
 
   // Check that the function is defined if it's an inline runtime call.
   if (function == NULL && name->Get(0) == '_') {
-    ParserTraits::ReportMessage("not_defined",
-                                Vector<Handle<String> >(&name, 1));
+    ParserTraits::ReportMessage("not_defined", name);
     *ok = false;
     return NULL;
   }
 
   // We have a valid intrinsics call or a call to a builtin.
   return factory()->NewCallRuntime(name, function, args, pos);
 }
 
 
 Literal* Parser::GetLiteralUndefined(int position) {
   return factory()->NewLiteral(
       isolate()->factory()->undefined_value(), position);
 }
 
 
 void Parser::CheckConflictingVarDeclarations(Scope* scope, bool* ok) {
   Declaration* decl = scope->CheckConflictingVarDeclarations();
   if (decl != NULL) {
     // In harmony mode we treat conflicting variable bindinds as early
     // errors. See ES5 16 for a definition of early errors.
     Handle<String> name = decl->proxy()->name();
-    SmartArrayPointer<char> c_string = name->ToCString(DISALLOW_NULLS);
-    const char* elms[1] = { c_string.get() };
-    Vector<const char*> args(elms, 1);
     int position = decl->proxy()->position();
     Scanner::Location location = position == RelocInfo::kNoPosition
         ? Scanner::Location::invalid()
         : Scanner::Location(position, position + 1);
-    ParserTraits::ReportMessageAt(location, "var_redeclaration", args);
+    ParserTraits::ReportMessageAt(location, "var_redeclaration", name);
     *ok = false;
   }
 }
 
 
 // ----------------------------------------------------------------------------
 // Parser support
 
 
 bool Parser::TargetStackContainsLabel(Handle<String> label) {
@@ skipping 954 matching lines @@
     } else {
       result = ParseProgram();
     }
   } else {
     SetCachedData(info()->cached_data(), info()->cached_data_mode());
     if (info()->cached_data_mode() == CONSUME_CACHED_DATA &&
         (*info()->cached_data())->has_error()) {
       ScriptData* cached_data = *(info()->cached_data());
       Scanner::Location loc = cached_data->MessageLocation();
       const char* message = cached_data->BuildMessage();
-      Vector<const char*> args = cached_data->BuildArgs();
-      ParserTraits::ReportMessageAt(loc, message, args,
+      const char* arg = cached_data->BuildArg();
+      ParserTraits::ReportMessageAt(loc, message, arg,
                                     cached_data->IsReferenceError());
       DeleteArray(message);
-      for (int i = 0; i < args.length(); i++) {
-        DeleteArray(args[i]);
-      }
-      DeleteArray(args.start());
+      DeleteArray(arg);
       ASSERT(info()->isolate()->has_pending_exception());
     } else {
       result = ParseProgram();
     }
   }
   info()->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal