Parser: add usage counters for "use asm".

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 "src/v8.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/bootstrapper.h"
 #include "src/char-predicates-inl.h"
@@ skipping 765 matching lines @@
       pending_error_char_arg_(NULL) {
   ASSERT(!script_.is_null());
   isolate_->set_ast_node_id(0);
   set_allow_harmony_scoping(!info->is_native() && FLAG_harmony_scoping);
   set_allow_modules(!info->is_native() && FLAG_harmony_modules);
   set_allow_natives_syntax(FLAG_allow_natives_syntax || info->is_native());
   set_allow_lazy(false);  // Must be explicitly enabled.
   set_allow_generators(FLAG_harmony_generators);
   set_allow_for_of(FLAG_harmony_iteration);
   set_allow_harmony_numeric_literals(FLAG_harmony_numeric_literals);
+  for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
+       ++feature) {
+    use_counts_[feature] = 0;
+  }
 }
 
 
 FunctionLiteral* Parser::ParseProgram() {
   // TODO(bmeurer): We temporarily need to pass allow_nesting = true here,
   // see comment for HistogramTimerScope class.
   HistogramTimerScope timer_scope(isolate()->counters()->parse(), true);
   Handle<String> source(String::cast(script_->source()));
   isolate()->counters()->total_parse_size()->Increment(source->length());
   ElapsedTimer timer;
@@ skipping 284 matching lines @@
     }
 
     if (directive_prologue) {
       // A shot at a directive.
       ExpressionStatement* e_stat;
       Literal* literal;
       // Still processing directive prologue?
       if ((e_stat = stat->AsExpressionStatement()) != NULL &&
           (literal = e_stat->expression()->AsLiteral()) != NULL &&
           literal->raw_value()->IsString()) {
-        // Check "use strict" directive (ES5 14.1).
+        // Check "use strict" directive (ES5 14.1) and "use asm" directive. Only
+        // one can be present.
         if (strict_mode() == SLOPPY &&
             literal->raw_value()->AsString() ==
                 ast_value_factory_->use_strict_string() &&
-            token_loc.end_pos - token_loc.beg_pos == 12) {
+            token_loc.end_pos - token_loc.beg_pos ==
+                ast_value_factory_->use_strict_string()->length() + 2) {
           // TODO(mstarzinger): Global strict eval calls, need their own scope
           // as specified in ES5 10.4.2(3). The correct fix would be to always
           // add this scope in DoParseProgram(), but that requires adaptations
           // all over the code base, so we go with a quick-fix for now.
           // In the same manner, we have to patch the parsing mode.
           if (is_eval && !scope_->is_eval_scope()) {
             ASSERT(scope_->is_global_scope());
             Scope* scope = NewScope(scope_, EVAL_SCOPE);
             scope->set_start_position(scope_->start_position());
             scope->set_end_position(scope_->end_position());
             scope_ = scope;
             mode_ = PARSE_EAGERLY;
           }
           scope_->SetStrictMode(STRICT);
           // "use strict" is the only directive for now.
           directive_prologue = false;
+        } else if (literal->raw_value()->AsString() ==
+                       ast_value_factory_->use_asm_string() &&
+                   token_loc.end_pos - token_loc.beg_pos ==
+                       ast_value_factory_->use_asm_string()->length() + 2) {
+          // Store the usage count; The actual use counter on the isolate is
+          // incremented after parsing is done.
+          ++use_counts_[v8::Isolate::kUseAsm];
         }
       } else {
         // End of the directive prologue.
         directive_prologue = false;
       }
     }
 
     processor->Add(stat, zone());
   }
 
@@ skipping 2771 matching lines @@
 
     Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
     Handle<Object> result = pending_error_is_reference_error_
         ? factory->NewReferenceError(pending_error_message_, array)
         : factory->NewSyntaxError(pending_error_message_, array);
     isolate()->Throw(*result, &location);
   }
 }
 
 
+void Parser::InternalizeUseCounts() {
+  for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
+       ++feature) {
+    for (int i = 0; i < use_counts_[feature]; ++i) {
+      isolate()->CountUsage(v8::Isolate::UseCounterFeature(feature));
+    }
+  }
+}
+
+
 // ----------------------------------------------------------------------------
 // Regular expressions
 
 
 RegExpParser::RegExpParser(FlatStringReader* in,
                            Handle<String>* error,
                            bool multiline,
                            Zone* zone)
     : isolate_(zone->isolate()),
       zone_(zone),
@@ skipping 921 matching lines @@
       result = ParseProgram();
     }
   }
   info()->SetFunction(result);
   ASSERT(ast_value_factory_->IsInternalized());
   // info takes ownership of ast_value_factory_.
   if (info()->ast_value_factory() == NULL) {
     info()->SetAstValueFactory(ast_value_factory_);
   }
   ast_value_factory_ = NULL;
+
+  InternalizeUseCounts();
+
   return (result != NULL);
 }
 
 } }  // namespace v8::internal