Merge up to 8597 to experimental/gc from the bleeding edge.

src/utils.h

Index: src/utils.h
===================================================================
--- src/utils.h	(revision 8618)
+++ src/utils.h	(working copy)
@@ -52,11 +52,9 @@
 
 
 // X must be a power of 2.  Returns the number of trailing zeros.
-template <typename T>
-static inline int WhichPowerOf2(T x) {
+static inline int WhichPowerOf2(uint32_t x) {
   ASSERT(IsPowerOf2(x));
   ASSERT(x != 0);
-  if (x < 0) return 31;
   int bits = 0;
 #ifdef DEBUG
   int original_x = x;
@@ -801,6 +799,98 @@
   return BitCastHelper<Dest, Source>::cast(source);
 }
 
+
+template<typename ElementType, int NumElements>
+class EmbeddedContainer {
+ public:
+  EmbeddedContainer() : elems_() { }
+
+  int length() { return NumElements; }
+  ElementType& operator[](int i) {
+    ASSERT(i < length());
+    return elems_[i];
+  }
+
+ private:
+  ElementType elems_[NumElements];
+};
+
+
+template<typename ElementType>
+class EmbeddedContainer<ElementType, 0> {
+ public:
+  int length() { return 0; }
+  ElementType& operator[](int i) {
+    UNREACHABLE();
+    static ElementType t = 0;
+    return t;
+  }
+};
+
+
+// Helper class for building result strings in a character buffer. The
+// purpose of the class is to use safe operations that checks the
+// buffer bounds on all operations in debug mode.
+// This simple base class does not allow formatted output.
+class SimpleStringBuilder {
+ public:
+  // Create a string builder with a buffer of the given size. The
+  // buffer is allocated through NewArray<char> and must be
+  // deallocated by the caller of Finalize().
+  explicit SimpleStringBuilder(int size);
+
+  SimpleStringBuilder(char* buffer, int size)
+      : buffer_(buffer, size), position_(0) { }
+
+  ~SimpleStringBuilder() { if (!is_finalized()) Finalize(); }
+
+  int size() const { return buffer_.length(); }
+
+  // Get the current position in the builder.
+  int position() const {
+    ASSERT(!is_finalized());
+    return position_;
+  }
+
+  // Reset the position.
+  void Reset() { position_ = 0; }
+
+  // Add a single character to the builder. It is not allowed to add
+  // 0-characters; use the Finalize() method to terminate the string
+  // instead.
+  void AddCharacter(char c) {
+    ASSERT(c != '\0');
+    ASSERT(!is_finalized() && position_ < buffer_.length());
+    buffer_[position_++] = c;
+  }
+
+  // Add an entire string to the builder. Uses strlen() internally to
+  // compute the length of the input string.
+  void AddString(const char* s);
+
+  // Add the first 'n' characters of the given string 's' to the
+  // builder. The input string must have enough characters.
+  void AddSubstring(const char* s, int n);
+
+  // Add character padding to the builder. If count is non-positive,
+  // nothing is added to the builder.
+  void AddPadding(char c, int count);
+
+  // Add the decimal representation of the value.
+  void AddDecimalInteger(int value);
+
+  // Finalize the string by 0-terminating it and returning the buffer.
+  char* Finalize();
+
+ protected:
+  Vector<char> buffer_;
+  int position_;
+
+  bool is_finalized() const { return position_ < 0; }
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(SimpleStringBuilder);
+};
+
 } }  // namespace v8::internal
 
 #endif  // V8_UTILS_H_