Move V8 to external/v8

Change-Id: If68025d67453785a651c5dfb34fad298c16676a4

1 files changed, 581 insertions, 0 deletions

diff --git a/src/utils.h b/src/utils.h
new file mode 100644
index 00000000..275dbb5c
--- /dev/null
+++ b/src/utils.h
@@ -0,0 +1,581 @@
+// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_UTILS_H_
+#define V8_UTILS_H_
+
+#include <stdlib.h>
+
+namespace v8 {
+namespace internal {
+
+// ----------------------------------------------------------------------------
+// General helper functions
+
+// Returns true iff x is a power of 2.  Does not work for zero.
+template <typename T>
+static inline bool IsPowerOf2(T x) {
+  return (x & (x - 1)) == 0;
+}
+
+
+// The C++ standard leaves the semantics of '>>' undefined for
+// negative signed operands. Most implementations do the right thing,
+// though.
+static inline int ArithmeticShiftRight(int x, int s) {
+  return x >> s;
+}
+
+
+// Compute the 0-relative offset of some absolute value x of type T.
+// This allows conversion of Addresses and integral types into
+// 0-relative int offsets.
+template <typename T>
+static inline intptr_t OffsetFrom(T x) {
+  return x - static_cast<T>(0);
+}
+
+
+// Compute the absolute value of type T for some 0-relative offset x.
+// This allows conversion of 0-relative int offsets into Addresses and
+// integral types.
+template <typename T>
+static inline T AddressFrom(intptr_t x) {
+  return static_cast<T>(0) + x;
+}
+
+
+// Return the largest multiple of m which is <= x.
+template <typename T>
+static inline T RoundDown(T x, int m) {
+  ASSERT(IsPowerOf2(m));
+  return AddressFrom<T>(OffsetFrom(x) & -m);
+}
+
+
+// Return the smallest multiple of m which is >= x.
+template <typename T>
+static inline T RoundUp(T x, int m) {
+  return RoundDown(x + m - 1, m);
+}
+
+
+template <typename T>
+static int Compare(const T& a, const T& b) {
+  if (a == b)
+    return 0;
+  else if (a < b)
+    return -1;
+  else
+    return 1;
+}
+
+
+template <typename T>
+static int PointerValueCompare(const T* a, const T* b) {
+  return Compare<T>(*a, *b);
+}
+
+
+// Returns the smallest power of two which is >= x. If you pass in a
+// number that is already a power of two, it is returned as is.
+uint32_t RoundUpToPowerOf2(uint32_t x);
+
+
+template <typename T>
+static inline bool IsAligned(T value, T alignment) {
+  ASSERT(IsPowerOf2(alignment));
+  return (value & (alignment - 1)) == 0;
+}
+
+
+// Returns true if (addr + offset) is aligned.
+static inline bool IsAddressAligned(Address addr,
+                                    intptr_t alignment,
+                                    int offset) {
+  intptr_t offs = OffsetFrom(addr + offset);
+  return IsAligned(offs, alignment);
+}
+
+
+// Returns the maximum of the two parameters.
+template <typename T>
+static T Max(T a, T b) {
+  return a < b ? b : a;
+}
+
+
+// Returns the minimum of the two parameters.
+template <typename T>
+static T Min(T a, T b) {
+  return a < b ? a : b;
+}
+
+
+// ----------------------------------------------------------------------------
+// BitField is a help template for encoding and decode bitfield with
+// unsigned content.
+template<class T, int shift, int size>
+class BitField {
+ public:
+  // Tells whether the provided value fits into the bit field.
+  static bool is_valid(T value) {
+    return (static_cast<uint32_t>(value) & ~((1U << (size)) - 1)) == 0;
+  }
+
+  // Returns a uint32_t mask of bit field.
+  static uint32_t mask() {
+    return (1U << (size + shift)) - (1U << shift);
+  }
+
+  // Returns a uint32_t with the bit field value encoded.
+  static uint32_t encode(T value) {
+    ASSERT(is_valid(value));
+    return static_cast<uint32_t>(value) << shift;
+  }
+
+  // Extracts the bit field from the value.
+  static T decode(uint32_t value) {
+    return static_cast<T>((value >> shift) & ((1U << (size)) - 1));
+  }
+};
+
+
+// ----------------------------------------------------------------------------
+// Support for compressed, machine-independent encoding
+// and decoding of integer values of arbitrary size.
+
+// Encoding and decoding from/to a buffer at position p;
+// the result is the position after the encoded integer.
+// Small signed integers in the range -64 <= x && x < 64
+// are encoded in 1 byte; larger values are encoded in 2
+// or more bytes. At most sizeof(int) + 1 bytes are used
+// in the worst case.
+byte* EncodeInt(byte* p, int x);
+byte* DecodeInt(byte* p, int* x);
+
+
+// Encoding and decoding from/to a buffer at position p - 1
+// moving backward; the result is the position of the last
+// byte written. These routines are useful to read/write
+// into a buffer starting at the end of the buffer.
+byte* EncodeUnsignedIntBackward(byte* p, unsigned int x);
+
+// The decoding function is inlined since its performance is
+// important to mark-sweep garbage collection.
+inline byte* DecodeUnsignedIntBackward(byte* p, unsigned int* x) {
+  byte b = *--p;
+  if (b >= 128) {
+    *x = static_cast<unsigned int>(b) - 128;
+    return p;
+  }
+  unsigned int r = static_cast<unsigned int>(b);
+  unsigned int s = 7;
+  b = *--p;
+  while (b < 128) {
+    r |= static_cast<unsigned int>(b) << s;
+    s += 7;
+    b = *--p;
+  }
+  // b >= 128
+  *x = r | ((static_cast<unsigned int>(b) - 128) << s);
+  return p;
+}
+
+
+// ----------------------------------------------------------------------------
+// Hash function.
+
+uint32_t ComputeIntegerHash(uint32_t key);
+
+
+// ----------------------------------------------------------------------------
+// I/O support.
+
+// Our version of printf(). Avoids compilation errors that we get
+// with standard printf when attempting to print pointers, etc.
+// (the errors are due to the extra compilation flags, which we
+// want elsewhere).
+void PrintF(const char* format, ...);
+
+// Our version of fflush.
+void Flush();
+
+
+// Read a line of characters after printing the prompt to stdout. The resulting
+// char* needs to be disposed off with DeleteArray by the caller.
+char* ReadLine(const char* prompt);
+
+
+// Read and return the raw bytes in a file. the size of the buffer is returned
+// in size.
+// The returned buffer must be freed by the caller.
+byte* ReadBytes(const char* filename, int* size, bool verbose = true);
+
+
+// Write size chars from str to the file given by filename.
+// The file is overwritten. Returns the number of chars written.
+int WriteChars(const char* filename,
+               const char* str,
+               int size,
+               bool verbose = true);
+
+
+// Write size bytes to the file given by filename.
+// The file is overwritten. Returns the number of bytes written.
+int WriteBytes(const char* filename,
+               const byte* bytes,
+               int size,
+               bool verbose = true);
+
+
+// Write the C code
+// const char* <varname> = "<str>";
+// const int <varname>_len = <len>;
+// to the file given by filename. Only the first len chars are written.
+int WriteAsCFile(const char* filename, const char* varname,
+                 const char* str, int size, bool verbose = true);
+
+
+// ----------------------------------------------------------------------------
+// Miscellaneous
+
+// A static resource holds a static instance that can be reserved in
+// a local scope using an instance of Access.  Attempts to re-reserve
+// the instance will cause an error.
+template <typename T>
+class StaticResource {
+ public:
+  StaticResource() : is_reserved_(false)  {}
+
+ private:
+  template <typename S> friend class Access;
+  T instance_;
+  bool is_reserved_;
+};
+
+
+// Locally scoped access to a static resource.
+template <typename T>
+class Access {
+ public:
+  explicit Access(StaticResource<T>* resource)
+    : resource_(resource)
+    , instance_(&resource->instance_) {
+    ASSERT(!resource->is_reserved_);
+    resource->is_reserved_ = true;
+  }
+
+  ~Access() {
+    resource_->is_reserved_ = false;
+    resource_ = NULL;
+    instance_ = NULL;
+  }
+
+  T* value()  { return instance_; }
+  T* operator -> ()  { return instance_; }
+
+ private:
+  StaticResource<T>* resource_;
+  T* instance_;
+};
+
+
+template <typename T>
+class Vector {
+ public:
+  Vector() : start_(NULL), length_(0) {}
+  Vector(T* data, int length) : start_(data), length_(length) {
+    ASSERT(length == 0 || (length > 0 && data != NULL));
+  }
+
+  static Vector<T> New(int length) {
+    return Vector<T>(NewArray<T>(length), length);
+  }
+
+  // Returns a vector using the same backing storage as this one,
+  // spanning from and including 'from', to but not including 'to'.
+  Vector<T> SubVector(int from, int to) {
+    ASSERT(from < length_);
+    ASSERT(to <= length_);
+    ASSERT(from < to);
+    return Vector<T>(start() + from, to - from);
+  }
+
+  // Returns the length of the vector.
+  int length() const { return length_; }
+
+  // Returns whether or not the vector is empty.
+  bool is_empty() const { return length_ == 0; }
+
+  // Returns the pointer to the start of the data in the vector.
+  T* start() const { return start_; }
+
+  // Access individual vector elements - checks bounds in debug mode.
+  T& operator[](int index) const {
+    ASSERT(0 <= index && index < length_);
+    return start_[index];
+  }
+
+  T& first() { return start_[0]; }
+
+  T& last() { return start_[length_ - 1]; }
+
+  // Returns a clone of this vector with a new backing store.
+  Vector<T> Clone() const {
+    T* result = NewArray<T>(length_);
+    for (int i = 0; i < length_; i++) result[i] = start_[i];
+    return Vector<T>(result, length_);
+  }
+
+  void Sort(int (*cmp)(const T*, const T*)) {
+    typedef int (*RawComparer)(const void*, const void*);
+    qsort(start(),
+          length(),
+          sizeof(T),
+          reinterpret_cast<RawComparer>(cmp));
+  }
+
+  void Sort() {
+    Sort(PointerValueCompare<T>);
+  }
+
+  void Truncate(int length) {
+    ASSERT(length <= length_);
+    length_ = length;
+  }
+
+  // Releases the array underlying this vector. Once disposed the
+  // vector is empty.
+  void Dispose() {
+    if (is_empty()) return;
+    DeleteArray(start_);
+    start_ = NULL;
+    length_ = 0;
+  }
+
+  inline Vector<T> operator+(int offset) {
+    ASSERT(offset < length_);
+    return Vector<T>(start_ + offset, length_ - offset);
+  }
+
+  // Factory method for creating empty vectors.
+  static Vector<T> empty() { return Vector<T>(NULL, 0); }
+
+ protected:
+  void set_start(T* start) { start_ = start; }
+
+ private:
+  T* start_;
+  int length_;
+};
+
+
+// A temporary assignment sets a (non-local) variable to a value on
+// construction and resets it the value on destruction.
+template <typename T>
+class TempAssign {
+ public:
+  TempAssign(T* var, T value): var_(var), old_value_(*var) {
+    *var = value;
+  }
+
+  ~TempAssign() { *var_ = old_value_; }
+
+ private:
+  T* var_;
+  T old_value_;
+};
+
+
+template <typename T, int kSize>
+class EmbeddedVector : public Vector<T> {
+ public:
+  EmbeddedVector() : Vector<T>(buffer_, kSize) { }
+
+  // When copying, make underlying Vector to reference our buffer.
+  EmbeddedVector(const EmbeddedVector& rhs)
+      : Vector<T>(rhs) {
+    memcpy(buffer_, rhs.buffer_, sizeof(T) * kSize);
+    set_start(buffer_);
+  }
+
+  EmbeddedVector& operator=(const EmbeddedVector& rhs) {
+    if (this == &rhs) return *this;
+    Vector<T>::operator=(rhs);
+    memcpy(buffer_, rhs.buffer_, sizeof(T) * kSize);
+    set_start(buffer_);
+    return *this;
+  }
+
+ private:
+  T buffer_[kSize];
+};
+
+
+template <typename T>
+class ScopedVector : public Vector<T> {
+ public:
+  explicit ScopedVector(int length) : Vector<T>(NewArray<T>(length), length) { }
+  ~ScopedVector() {
+    DeleteArray(this->start());
+  }
+};
+
+
+inline Vector<const char> CStrVector(const char* data) {
+  return Vector<const char>(data, static_cast<int>(strlen(data)));
+}
+
+inline Vector<char> MutableCStrVector(char* data) {
+  return Vector<char>(data, static_cast<int>(strlen(data)));
+}
+
+inline Vector<char> MutableCStrVector(char* data, int max) {
+  int length = static_cast<int>(strlen(data));
+  return Vector<char>(data, (length < max) ? length : max);
+}
+
+template <typename T>
+inline Vector< Handle<Object> > HandleVector(v8::internal::Handle<T>* elms,
+                                             int length) {
+  return Vector< Handle<Object> >(
+      reinterpret_cast<v8::internal::Handle<Object>*>(elms), length);
+}
+
+
+// Simple support to read a file into a 0-terminated C-string.
+// The returned buffer must be freed by the caller.
+// On return, *exits tells whether the file existed.
+Vector<const char> ReadFile(const char* filename,
+                            bool* exists,
+                            bool verbose = true);
+
+
+// Simple wrapper that allows an ExternalString to refer to a
+// Vector<const char>. Doesn't assume ownership of the data.
+class AsciiStringAdapter: public v8::String::ExternalAsciiStringResource {
+ public:
+  explicit AsciiStringAdapter(Vector<const char> data) : data_(data) {}
+
+  virtual const char* data() const { return data_.start(); }
+
+  virtual size_t length() const { return data_.length(); }
+
+ private:
+  Vector<const char> data_;
+};
+
+
+// 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.
+class StringBuilder {
+ 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 StringBuilder(int size);
+
+  StringBuilder(char* buffer, int size)
+      : buffer_(buffer, size), position_(0) { }
+
+  ~StringBuilder() { 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 formatted contents to the builder just like printf().
+  void AddFormatted(const char* format, ...);
+
+  // Add character padding to the builder. If count is non-positive,
+  // nothing is added to the builder.
+  void AddPadding(char c, int count);
+
+  // Finalize the string by 0-terminating it and returning the buffer.
+  char* Finalize();
+
+ private:
+  Vector<char> buffer_;
+  int position_;
+
+  bool is_finalized() const { return position_ < 0; }
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(StringBuilder);
+};
+
+
+// Copy from ASCII/16bit chars to ASCII/16bit chars.
+template <typename sourcechar, typename sinkchar>
+static inline void CopyChars(sinkchar* dest, const sourcechar* src, int chars) {
+  sinkchar* limit = dest + chars;
+#ifdef V8_HOST_CAN_READ_UNALIGNED
+  if (sizeof(*dest) == sizeof(*src)) {
+    // Number of characters in a uint32_t.
+    static const int kStepSize = sizeof(uint32_t) / sizeof(*dest);  // NOLINT
+    while (dest <= limit - kStepSize) {
+      *reinterpret_cast<uint32_t*>(dest) =
+          *reinterpret_cast<const uint32_t*>(src);
+      dest += kStepSize;
+      src += kStepSize;
+    }
+  }
+#endif
+  while (dest < limit) {
+    *dest++ = static_cast<sinkchar>(*src++);
+  }
+}
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_UTILS_H_