Improve rendering of callsite with non-function target.

This hackily disambiguates multiple calls for the iterator protocols in ForOf / Yield* by adding -2 / -1 to the pos.

BUG=v8:3953
LOG=y

Review URL: https://codereview.chromium.org/1491923003

Cr-Commit-Position: refs/heads/master@{#32527}

src/ast/prettyprinter.cc

@@ -13,13 +13,14 @@
 namespace v8 {
 namespace internal {
 
-CallPrinter::CallPrinter(Isolate* isolate) {
+CallPrinter::CallPrinter(Isolate* isolate, bool is_builtin) {
   output_ = NULL;
   size_ = 0;
   pos_ = 0;
   position_ = 0;
   found_ = false;
   done_ = false;
+  is_builtin_ = is_builtin;
   InitializeAstVisitor(isolate);
 }
 
@@ -192,8 +193,9 @@ void CallPrinter::VisitForInStatement(ForInStatement* node) {
 
 void CallPrinter::VisitForOfStatement(ForOfStatement* node) {
   Find(node->each());
-  Find(node->iterable());
+  Find(node->assign_iterator());
   Find(node->body());
+  Find(node->next_result());
 }
 
 
@@ -239,13 +241,13 @@ void CallPrinter::VisitConditional(Conditional* node) {
 
 
 void CallPrinter::VisitLiteral(Literal* node) {
-  PrintLiteral(node->value(), true);
+  PrintLiteral(*node->value(), true);
 }
 
 
 void CallPrinter::VisitRegExpLiteral(RegExpLiteral* node) {
   Print("/");
-  PrintLiteral(node->pattern(), false);
+  PrintLiteral(*node->pattern(), false);
   Print("/");
   if (node->flags() & RegExp::kGlobal) Print("g");
   if (node->flags() & RegExp::kIgnoreCase) Print("i");
@@ -273,7 +275,12 @@ void CallPrinter::VisitArrayLiteral(ArrayLiteral* node) {
 
 
 void CallPrinter::VisitVariableProxy(VariableProxy* node) {
-  PrintLiteral(node->name(), false);
+  if (is_builtin_) {
+    // Variable names of builtins are meaningless due to minification.
+    Print("(var)");
+  } else {
+    PrintLiteral(*node->name(), false);
+  }
 }
 
 
@@ -295,7 +302,7 @@ void CallPrinter::VisitProperty(Property* node) {
   if (literal != NULL && literal->value()->IsInternalizedString()) {
     Find(node->obj(), true);
     Print(".");
-    PrintLiteral(literal->value(), false);
+    PrintLiteral(*literal->value(), false);
   } else {
     Find(node->obj(), true);
     Print("[");
@@ -307,7 +314,15 @@ void CallPrinter::VisitProperty(Property* node) {
 
 void CallPrinter::VisitCall(Call* node) {
   bool was_found = !found_ && node->position() == position_;
-  if (was_found) found_ = true;
+  if (was_found) {
+    // Bail out if the error is caused by a direct call to a variable in builtin
+    // code. The variable name is meaningless due to minification.
+    if (is_builtin_ && node->expression()->IsVariableProxy()) {
+      done_ = true;
+      return;
+    }
+    found_ = true;
+  }
   Find(node->expression(), true);
   if (!was_found) Print("(...)");
   FindArguments(node->arguments());
@@ -317,7 +332,15 @@ void CallPrinter::VisitCall(Call* node) {
 
 void CallPrinter::VisitCallNew(CallNew* node) {
   bool was_found = !found_ && node->position() == position_;
-  if (was_found) found_ = true;
+  if (was_found) {
+    // Bail out if the error is caused by a direct call to a variable in builtin
+    // code. The variable name is meaningless due to minification.
+    if (is_builtin_ && node->expression()->IsVariableProxy()) {
+      done_ = true;
+      return;
+    }
+    found_ = true;
+  }
   Find(node->expression(), was_found);
   FindArguments(node->arguments());
   if (was_found) done_ = true;
@@ -413,14 +436,11 @@ void CallPrinter::FindArguments(ZoneList<Expression*>* arguments) {
 }
 
 
-void CallPrinter::PrintLiteral(Handle<Object> value, bool quote) {
-  Object* object = *value;
+void CallPrinter::PrintLiteral(Object* value, bool quote) {
+  Object* object = value;
   if (object->IsString()) {
-    String* string = String::cast(object);
     if (quote) Print("\"");
-    for (int i = 0; i < string->length(); i++) {
-      Print("%c", string->Get(i));
-    }
+    Print("%s", String::cast(object)->ToCString().get());
     if (quote) Print("\"");
   } else if (object->IsNull()) {
     Print("null");
@@ -432,12 +452,15 @@ void CallPrinter::PrintLiteral(Handle<Object> value, bool quote) {
     Print("undefined");
   } else if (object->IsNumber()) {
     Print("%g", object->Number());
+  } else if (object->IsSymbol()) {
+    // Symbols can only occur as literals if they were inserted by the parser.
+    PrintLiteral(Symbol::cast(object)->name(), false);
   }
 }
 
 
 void CallPrinter::PrintLiteral(const AstRawString* value, bool quote) {
-  PrintLiteral(value->string(), quote);
+  PrintLiteral(*value->string(), quote);
 }
 
 

src/ast/prettyprinter.h

@@ -13,7 +13,7 @@ namespace internal {
 
 class CallPrinter : public AstVisitor {
  public:
-  explicit CallPrinter(Isolate* isolate);
+  explicit CallPrinter(Isolate* isolate, bool is_builtin);
   virtual ~CallPrinter();
 
   // The following routine prints the node with position |position| into a
@@ -37,11 +37,12 @@ class CallPrinter : public AstVisitor {
   int position_;  // position of ast node to print
   bool found_;
   bool done_;
+  bool is_builtin_;
 
   DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
 
  protected:
-  void PrintLiteral(Handle<Object> value, bool quote);
+  void PrintLiteral(Object* value, bool quote);
   void PrintLiteral(const AstRawString* value, bool quote);
   void FindStatements(ZoneList<Statement*>* statements);
   void FindArguments(ZoneList<Expression*>* arguments);

src/parsing/parser.cc

@@ -852,10 +852,9 @@ Expression* ParserTraits::ExpressionFromString(int pos, Scanner* scanner,
 
 
 Expression* ParserTraits::GetIterator(Expression* iterable,
-                                      AstNodeFactory* factory) {
+                                      AstNodeFactory* factory, int pos) {
   Expression* iterator_symbol_literal =
       factory->NewSymbolLiteral("iterator_symbol", RelocInfo::kNoPosition);
-  int pos = iterable->position();
   Expression* prop =
       factory->NewProperty(iterable, iterator_symbol_literal, pos);
   Zone* zone = parser_->zone();
@@ -3339,17 +3338,22 @@ void Parser::InitializeForEachStatement(ForEachStatement* stmt,
     Expression* assign_each;
 
     // iterator = subject[Symbol.iterator]()
+    // Hackily disambiguate o from o.next and o [Symbol.iterator]().
+    // TODO(verwaest): Come up with a better solution.
     assign_iterator = factory()->NewAssignment(
         Token::ASSIGN, factory()->NewVariableProxy(iterator),
-        GetIterator(subject, factory()), subject->position());
+        GetIterator(subject, factory(), subject->position() - 2),
+        subject->position());
 
     // !%_IsJSReceiver(result = iterator.next()) &&
     //     %ThrowIteratorResultNotAnObject(result)
     {
       // result = iterator.next()
       Expression* iterator_proxy = factory()->NewVariableProxy(iterator);
-      next_result =
-          BuildIteratorNextResult(iterator_proxy, result, subject->position());
+      // Hackily disambiguate o from o.next and o [Symbol.iterator]().
+      // TODO(verwaest): Come up with a better solution.
+      next_result = BuildIteratorNextResult(iterator_proxy, result,
+                                            subject->position() - 1);
     }
 
     // result.done

src/parsing/parser.h

@@ -784,7 +784,8 @@ class ParserTraits {
                                        Scope* scope, AstNodeFactory* factory);
   Expression* ExpressionFromString(int pos, Scanner* scanner,
                                    AstNodeFactory* factory);
-  Expression* GetIterator(Expression* iterable, AstNodeFactory* factory);
+  Expression* GetIterator(Expression* iterable, AstNodeFactory* factory,
+                          int pos);
   ZoneList<v8::internal::Expression*>* NewExpressionList(int size, Zone* zone) {
     return new(zone) ZoneList<v8::internal::Expression*>(size, zone);
   }

src/parsing/pattern-rewriter.cc

@@ -251,7 +251,7 @@ void Parser::PatternRewriter::VisitArrayLiteral(ArrayLiteral* node) {
                             zone());
 
   auto iterator = CreateTempVar(descriptor_->parser->GetIterator(
-      factory()->NewVariableProxy(temp), factory()));
+      factory()->NewVariableProxy(temp), factory(), RelocInfo::kNoPosition));
   auto done = CreateTempVar(
       factory()->NewBooleanLiteral(false, RelocInfo::kNoPosition));
   auto result = CreateTempVar();

src/parsing/preparser.h

@@ -1645,7 +1645,7 @@ class PreParserTraits {
                                            PreParserFactory* factory = NULL);
 
   PreParserExpression GetIterator(PreParserExpression iterable,
-                                  PreParserFactory* factory) {
+                                  PreParserFactory* factory, int pos) {
     return PreParserExpression::Default();
   }
 
@@ -3120,8 +3120,12 @@ ParserBase<Traits>::ParseYieldExpression(ExpressionClassifier* classifier,
   }
   if (kind == Yield::kDelegating) {
     // var iterator = subject[Symbol.iterator]();
-    expression = this->GetIterator(expression, factory());
+    // Hackily disambiguate o from o.next and o [Symbol.iterator]().
+    // TODO(verwaest): Come up with a better solution.
+    expression = this->GetIterator(expression, factory(), pos + 1);
   }
+  // Hackily disambiguate o from o.next and o [Symbol.iterator]().
+  // TODO(verwaest): Come up with a better solution.
   typename Traits::Type::YieldExpression yield =
       factory()->NewYield(generator_object, expression, kind, pos);
   return yield;

src/runtime/runtime-internal.cc

@@ -388,18 +388,44 @@ RUNTIME_FUNCTION(Runtime_HarmonyToString) {
 
 namespace {
 
+bool ComputeLocation(Isolate* isolate, MessageLocation* target) {
+  JavaScriptFrameIterator it(isolate);
+  if (!it.done()) {
+    JavaScriptFrame* frame = it.frame();
+    JSFunction* fun = frame->function();
+    Object* script = fun->shared()->script();
+    if (script->IsScript() &&
+        !(Script::cast(script)->source()->IsUndefined())) {
+      Handle<Script> casted_script(Script::cast(script));
+      // Compute the location from the function and the relocation info of the
+      // baseline code. For optimized code this will use the deoptimization
+      // information to get canonical location information.
+      List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
+      it.frame()->Summarize(&frames);
+      FrameSummary& summary = frames.last();
+      int pos = summary.code()->SourcePosition(summary.pc());
+      *target = MessageLocation(casted_script, pos, pos + 1, handle(fun));
+      return true;
+    }
+  }
+  return false;
+}
+
+
 Handle<String> RenderCallSite(Isolate* isolate, Handle<Object> object) {
   MessageLocation location;
-  if (isolate->ComputeLocation(&location)) {
+  if (ComputeLocation(isolate, &location)) {
     Zone zone;
     base::SmartPointer<ParseInfo> info(
         location.function()->shared()->is_function()
             ? new ParseInfo(&zone, location.function())
             : new ParseInfo(&zone, location.script()));
     if (Parser::ParseStatic(info.get())) {
-      CallPrinter printer(isolate);
+      CallPrinter printer(isolate, location.function()->shared()->IsBuiltin());
       const char* string = printer.Print(info->literal(), location.start_pos());
-      return isolate->factory()->NewStringFromAsciiChecked(string);
+      if (strlen(string) > 0) {
+        return isolate->factory()->NewStringFromAsciiChecked(string);
+      }
     } else {
       isolate->clear_pending_exception();
     }

test/mjsunit/es6/debug-promises/throw-with-undefined-reject.js

@@ -48,7 +48,7 @@ function listener(event, exec_state, event_data, data) {
       } else if (expected_events == 0) {
         // All of the frames on the stack are from native Javascript.
         assertEquals(0, exec_state.frameCount());
-        assertEquals("undefined is not a function",
+        assertEquals("(var).reject is not a function",
                      event_data.exception().message);
       } else {
         assertUnreachable();

test/mjsunit/es6/debug-stepnext-for.js

@@ -86,6 +86,9 @@ Debug.setListener(null);         // Break z
 print("log:\n"+ JSON.stringify(log));
 // The let declaration differs from var in that the loop variable
 // is declared in every iteration.
+// TODO(verwaest): For-of has hacky position numbers for Symbol.iterator and
+// .next. Restore to proper positions once the CallPrinter can disambiguate
+// based on other values.
 var expected = [
   // Entry
   "a2","b2",
@@ -99,12 +102,12 @@ var expected = [
   "f12","f7","F4","f7","F4","f7","F4","f7",
   // For-in-let: get enumerable, next, body, next,  ...
   "g16","g11","G4","g11","G4","g11","G4","g11",
-  // For-of-var: next(), body, next(), body, ...
-  "h16","H4","h16","H4","h16","H4","h16",
-  // For-of: next(), body, next(), body, ...
-  "i12","I4","i12","I4","i12","I4","i12",
-  // For-of-let: next(), body, next(), ...
-  "j16","J4","j16","J4","j16","J4","j16",
+  // For-of-var: [Symbol.iterator](), next(), body, next(), body, ...
+  "h16","h14","h15","H4","h15","H4","h15","H4","h15",
+  // For-of: [Symbol.iterator](), next(), body, next(), body, ...
+  "i12","i10","i11","I4","i11","I4","i11","I4","i11",
+  // For-of-let: [Symbol.iterator](), next(), body, next(), ...
+  "j16","j14","j15","J4","j15","J4","j15","J4","j15",
   // For-var: var decl, condition, body, next, condition, body, ...
   "k7","k20","K4","k26","k20","K4","k26","k20","K4","k26","k20",
   // For: init, condition, body, next, condition, body, ...

test/webkit/fast/js/toString-overrides-expected.txt

@@ -28,10 +28,10 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 
 PASS [1].toString() is '1'
 PASS [1].toLocaleString() is 'toLocaleString'
-FAIL [1].toLocaleString() should be 1. Threw exception TypeError: [1].toLocaleString is not a function
+FAIL [1].toLocaleString() should be 1. Threw exception TypeError: (var).toLocaleString is not a function
 PASS [/r/].toString() is 'toString2'
 PASS [/r/].toLocaleString() is 'toLocaleString2'
-FAIL [/r/].toLocaleString() should be toString2. Threw exception TypeError: [/r/].toLocaleString is not a function
+FAIL [/r/].toLocaleString() should be toString2. Threw exception TypeError: (var).toLocaleString is not a function
 PASS caught is true
 PASS successfullyParsed is true
 

test/webkit/run-json-stringify-expected.txt

@@ -83,7 +83,7 @@ PASS tests[i](nativeJSON) is tests[i](JSON)
 function (jsonObject){
         return jsonObject.stringify({toJSON: Date.prototype.toJSON});
     }
-PASS tests[i](nativeJSON) threw exception TypeError: jsonObject.stringify is not a function.
+PASS tests[i](nativeJSON) threw exception TypeError: (var).toISOString is not a function.
 function (jsonObject){
         return jsonObject.stringify({toJSON: Date.prototype.toJSON, toISOString: function(){ return "custom toISOString"; }});
     }
@@ -101,7 +101,7 @@ function (jsonObject){
         d.toISOString = null;
         return jsonObject.stringify(d);
     }
-PASS tests[i](nativeJSON) threw exception TypeError: jsonObject.stringify is not a function.
+PASS tests[i](nativeJSON) threw exception TypeError: (var).toISOString is not a function.
 function (jsonObject){
         var d = new Date(0);
         d.toJSON = undefined;