Add support for javascript incompatibility warnings.

runtime/vm/flow_graph_builder.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/class_finalizer.h"
@@ skipping 19 matching lines @@
 #include "vm/zone.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, eliminate_type_checks, true,
             "Eliminate type checks when allowed by static type analysis.");
 DEFINE_FLAG(bool, print_ast, false, "Print abstract syntax tree.");
 DEFINE_FLAG(bool, print_scopes, false, "Print scopes of local variables.");
 DEFINE_FLAG(bool, trace_type_check_elimination, false,
             "Trace type check elimination at compile time.");
+DEFINE_FLAG(bool, warn_on_javascript_compatibility, false,
+            "Warn on incompatibilities between vm and dart2js.");
 DECLARE_FLAG(bool, enable_type_checks);
+DECLARE_FLAG(bool, warning_as_error);
+DECLARE_FLAG(bool, silent_warnings);
 
 
 // TODO(srdjan): Allow compiler to add constants as they are encountered in
 // the compilation.
 const double kCommonDoubleConstants[] =
     {-1.0, -0.5, -0.1, 0.0, 0.1, 0.5, 1.0, 2.0, 4.0, 5.0,
      10.0, 20.0, 30.0, 64.0, 255.0, NAN,
      // From dart:math
      2.718281828459045, 2.302585092994046, 0.6931471805599453,
      1.4426950408889634, 0.4342944819032518, 3.1415926535897932,
@@ skipping 898 matching lines @@
       true_successor_addresses_.AddArray(for_left.true_successor_addresses_);
       true_successor_addresses_.AddArray(for_right.true_successor_addresses_);
     }
     CloseFragment();
     return;
   }
   ValueGraphVisitor::VisitBinaryOpNode(node);
 }
 
 
-void EffectGraphVisitor::Bailout(const char* reason) {
+void EffectGraphVisitor::Bailout(const char* reason) const {
   owner()->Bailout(reason);
 }
 
 
-void EffectGraphVisitor::InlineBailout(const char* reason) {
+void EffectGraphVisitor::InlineBailout(const char* reason) const {
   owner()->parsed_function()->function().set_is_inlinable(false);
   if (owner()->IsInlining()) owner()->Bailout(reason);
 }
 
 
 // <Statement> ::= Return { value:                <Expression>
 //                          inlined_finally_list: <InlinedFinally>* }
 void EffectGraphVisitor::VisitReturnNode(ReturnNode* node) {
   ValueGraphVisitor for_value(owner());
   node->value()->Visit(&for_value);
@@ skipping 421 matching lines @@
                                                 Value* value,
                                                 const AbstractType& dst_type,
                                                 const String& dst_name) {
   if (CanSkipTypeCheck(token_pos, value, dst_type, dst_name)) {
     return value;
   }
   return Bind(BuildAssertAssignable(token_pos, value, dst_type, dst_name));
 }
 
 
+void FlowGraphBuilder::WarnOnJSIntegralNumTypeTest(
+    AstNode* node, const AbstractType& type) const {
+  if (is_optimizing()) {
+    // Warnings for constants are issued when the graph is built for the first
+    // time only, i.e. just before generating unoptimized code.
+    // They should not be repeated when generating optimized code.
+    return;
+  }
+  if (!(node->IsLiteralNode() && (type.IsIntType() || type.IsDoubleType()))) {
+    return;
+  }
+  const Instance& instance = node->AsLiteralNode()->literal();
+  if (type.IsIntType()) {
+    if (instance.IsDouble()) {
+      const Double& double_instance = Double::Cast(instance);
+      double value = double_instance.value();
+      if (floor(value) == value) {
+        Warning(node->token_pos(),
+                "javascript compatibility warning: integral value of type "
+                "'double' is also considered to be of type 'int'");
+      }
+    }
+  } else {
+    ASSERT(type.IsDoubleType());
+    if (instance.IsInteger()) {
+      Warning(node->token_pos(),
+              "javascript compatibility warning: integer value is also "
+              "considered to be of type 'double'");
+    }
+  }
+}
+
+
 void EffectGraphVisitor::BuildTypeTest(ComparisonNode* node) {
   ASSERT(Token::IsTypeTestOperator(node->kind()));
   const AbstractType& type = node->right()->AsTypeNode()->type();
   ASSERT(type.IsFinalized() && !type.IsMalformedOrMalbounded());
   const bool negate_result = (node->kind() == Token::kISNOT);
   // All objects are instances of type T if Object type is a subtype of type T.
   const Type& object_type = Type::Handle(Type::ObjectType());
   if (type.IsInstantiated() && object_type.IsSubtypeOf(type, NULL)) {
     // Must evaluate left side.
     EffectGraphVisitor for_left_value(owner());
     node->left()->Visit(&for_left_value);
     Append(for_left_value);
     ReturnDefinition(new ConstantInstr(Bool::Get(!negate_result)));
     return;
   }
+
+  // Check for javascript compatibility.
+  if (FLAG_warn_on_javascript_compatibility) {
+    owner()->WarnOnJSIntegralNumTypeTest(node->left(), type);
+  }
+
   ValueGraphVisitor for_left_value(owner());
   node->left()->Visit(&for_left_value);
   Append(for_left_value);
   PushArgumentInstr* push_left = PushArgument(for_left_value.value());
   PushArgumentInstr* push_instantiator = NULL;
   PushArgumentInstr* push_type_args = NULL;
   if (type.IsInstantiated()) {
     push_instantiator = PushArgument(BuildNullValue());
     push_type_args = PushArgument(BuildNullValue());
   } else {
@@ skipping 24 matching lines @@
       owner()->ic_data_array());
   ReturnDefinition(call);
 }
 
 
 void EffectGraphVisitor::BuildTypeCast(ComparisonNode* node) {
   ASSERT(Token::IsTypeCastOperator(node->kind()));
   ASSERT(!node->right()->AsTypeNode()->type().IsNull());
   const AbstractType& type = node->right()->AsTypeNode()->type();
   ASSERT(type.IsFinalized() && !type.IsMalformed() && !type.IsMalbounded());
+
+  // Check for javascript compatibility.
+  if (FLAG_warn_on_javascript_compatibility) {
+    owner()->WarnOnJSIntegralNumTypeTest(node->left(), type);
+  }
+
   ValueGraphVisitor for_value(owner());
   node->left()->Visit(&for_value);
   Append(for_value);
   const String& dst_name = String::ZoneHandle(
       Symbols::New(Exceptions::kCastErrorDstName));
   if (CanSkipTypeCheck(node->token_pos(),
                        for_value.value(),
                        type,
                        dst_name)) {
     ReturnValue(for_value.value());
@@ skipping 2407 matching lines @@
 
 void FlowGraphBuilder::PruneUnreachable() {
   ASSERT(osr_id_ != Isolate::kNoDeoptId);
   BitVector* block_marks = new BitVector(last_used_block_id_ + 1);
   bool found = graph_entry_->PruneUnreachable(this, graph_entry_, NULL, osr_id_,
                                               block_marks);
   ASSERT(found);
 }
 
 
+void FlowGraphBuilder::Warning(intptr_t token_pos,
+                               const char* format, ...) const {
+  if (FLAG_silent_warnings) return;
+  const Function& function = parsed_function_->function();
+  va_list args;
+  va_start(args, format);
+  const Error& error = Error::Handle(
+      LanguageError::NewFormattedV(Error::Handle(),  // No previous error.
+                                   Script::Handle(function.script()),
+                                   token_pos, LanguageError::kWarning,
+                                   Heap::kNew, format, args));
+  va_end(args);
+  if (FLAG_warning_as_error) {
+    Isolate::Current()->long_jump_base()->Jump(1, error);
+    UNREACHABLE();
+  } else {
+    OS::Print("%s", error.ToErrorCString());
+  }
+}
+
+
 void FlowGraphBuilder::Bailout(const char* reason) const {
   const Function& function = parsed_function_->function();
   const Error& error = Error::Handle(
       LanguageError::NewFormatted(Error::Handle(),  // No previous error.
                                   Script::Handle(function.script()),
                                   function.token_pos(),
-                                  LanguageError::kError,
+                                  LanguageError::kBailout,
                                   Heap::kNew,
                                   "FlowGraphBuilder Bailout: %s %s",
                                   String::Handle(function.name()).ToCString(),
                                   reason));
   Isolate::Current()->long_jump_base()->Jump(1, error);
+  UNREACHABLE();
 }
 
 }  // namespace dart