Replace boolean indications of strict mode by an enum value.

src/preparser.h

Index: src/preparser.h
diff --git a/src/preparser.h b/src/preparser.h
index 658693f4aae8c5dd7ee7ef9a5e2bd27623f560a0..6a0b97a56e0b056add04371da5415abc659e6d13 100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -408,6 +408,16 @@ class PreParser {
 
   typedef int Arguments;
 
+  // The Strict Mode (ECMA-262 5th edition, 4.2.2).
+  enum StrictModeFlag {
+    kNonStrictMode,
+    kStrictMode,
+    // This value is never used, but is needed to prevent GCC 4.5 from failing
+    // to compile when we assert that a flag is either kNonStrictMode or
+    // kStrictMode.
+    kInvalidStrictFlag
+  };
+
   class Scope {
    public:
     Scope(Scope** variable, ScopeType type)
@@ -417,7 +427,8 @@ class PreParser {
           materialized_literal_count_(0),
           expected_properties_(0),
           with_nesting_count_(0),
-          strict_((prev_ != NULL) && prev_->is_strict()) {
+          strict_mode_flag_((prev_ != NULL) ? prev_->strict_mode_flag()
+                            : kNonStrictMode) {
       *variable = this;
     }
     ~Scope() { *variable_ = prev_; }
@@ -427,8 +438,13 @@ class PreParser {
     int expected_properties() { return expected_properties_; }
     int materialized_literal_count() { return materialized_literal_count_; }
     bool IsInsideWith() { return with_nesting_count_ != 0; }
-    bool is_strict() { return strict_; }
-    void set_strict() { strict_ = true; }
+    bool is_strict_mode() { return strict_mode_flag_ == kStrictMode; }
+    StrictModeFlag strict_mode_flag() {
+      return strict_mode_flag_;
+    }
+    void set_strict_mode_flag(StrictModeFlag strict_mode_flag) {
+      strict_mode_flag_ = strict_mode_flag;
+    }
     void EnterWith() { with_nesting_count_++; }
     void LeaveWith() { with_nesting_count_--; }
 
@@ -439,7 +455,7 @@ class PreParser {
     int materialized_literal_count_;
     int expected_properties_;
     int with_nesting_count_;
-    bool strict_;
+    StrictModeFlag strict_mode_flag_;
   };
 
   // Private constructor only used in PreParseProgram.
@@ -470,7 +486,7 @@ class PreParser {
     if (stack_overflow_) return kPreParseStackOverflow;
     if (!ok) {
       ReportUnexpectedToken(scanner_->current_token());
-    } else if (scope_->is_strict()) {
+    } else if (scope_->is_strict_mode()) {
       CheckOctalLiteral(start_position, scanner_->location().end_pos, &ok);
     }
     return kPreParseSuccess;
@@ -575,10 +591,10 @@ class PreParser {
   bool peek_any_identifier();
 
   void set_strict_mode() {
-    scope_->set_strict();
+    scope_->set_strict_mode_flag(kStrictMode);
   }
 
-  bool strict_mode() { return scope_->is_strict(); }
+  bool strict_mode() { return scope_->strict_mode_flag() == kStrictMode; }
 
   void Consume(i::Token::Value token) { Next(); }