Move regexp implementation into its own folder.

src/regexp-stack.h

-// Copyright 2009 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.
-
-#ifndef V8_REGEXP_STACK_H_
-#define V8_REGEXP_STACK_H_
-
-namespace v8 {
-namespace internal {
-
-class RegExpStack;
-
-// Maintains a per-v8thread stack area that can be used by irregexp
-// implementation for its backtracking stack.
-// Since there is only one stack area, the Irregexp implementation is not
-// re-entrant. I.e., no regular expressions may be executed in the same thread
-// during a preempted Irregexp execution.
-class RegExpStackScope {
- public:
-  // Create and delete an instance to control the life-time of a growing stack.
-
-  // Initializes the stack memory area if necessary.
-  explicit RegExpStackScope(Isolate* isolate);
-  ~RegExpStackScope();  // Releases the stack if it has grown.
-
-  RegExpStack* stack() const { return regexp_stack_; }
-
- private:
-  RegExpStack* regexp_stack_;
-
-  DISALLOW_COPY_AND_ASSIGN(RegExpStackScope);
-};
-
-
-class RegExpStack {
- public:
-  // Number of allocated locations on the stack below the limit.
-  // No sequence of pushes must be longer that this without doing a stack-limit
-  // check.
-  static const int kStackLimitSlack = 32;
-
-  // Gives the top of the memory used as stack.
-  Address stack_base() {
-    DCHECK(thread_local_.memory_size_ != 0);
-    return thread_local_.memory_ + thread_local_.memory_size_;
-  }
-
-  // The total size of the memory allocated for the stack.
-  size_t stack_capacity() { return thread_local_.memory_size_; }
-
-  // If the stack pointer gets below the limit, we should react and
-  // either grow the stack or report an out-of-stack exception.
-  // There is only a limited number of locations below the stack limit,
-  // so users of the stack should check the stack limit during any
-  // sequence of pushes longer that this.
-  Address* limit_address() { return &(thread_local_.limit_); }
-
-  // Ensures that there is a memory area with at least the specified size.
-  // If passing zero, the default/minimum size buffer is allocated.
-  Address EnsureCapacity(size_t size);
-
-  // Thread local archiving.
-  static int ArchiveSpacePerThread() {
-    return static_cast<int>(sizeof(ThreadLocal));
-  }
-  char* ArchiveStack(char* to);
-  char* RestoreStack(char* from);
-  void FreeThreadResources() { thread_local_.Free(); }
-
- private:
-  RegExpStack();
-  ~RegExpStack();
-
-  // Artificial limit used when no memory has been allocated.
-  static const uintptr_t kMemoryTop = static_cast<uintptr_t>(-1);
-
-  // Minimal size of allocated stack area.
-  static const size_t kMinimumStackSize = 1 * KB;
-
-  // Maximal size of allocated stack area.
-  static const size_t kMaximumStackSize = 64 * MB;
-
-  // Structure holding the allocated memory, size and limit.
-  struct ThreadLocal {
-    ThreadLocal() { Clear(); }
-    // If memory_size_ > 0 then memory_ must be non-NULL.
-    Address memory_;
-    size_t memory_size_;
-    Address limit_;
-    void Clear() {
-      memory_ = NULL;
-      memory_size_ = 0;
-      limit_ = reinterpret_cast<Address>(kMemoryTop);
-    }
-    void Free();
-  };
-
-  // Address of allocated memory.
-  Address memory_address() {
-    return reinterpret_cast<Address>(&thread_local_.memory_);
-  }
-
-  // Address of size of allocated memory.
-  Address memory_size_address() {
-    return reinterpret_cast<Address>(&thread_local_.memory_size_);
-  }
-
-  // Resets the buffer if it has grown beyond the default/minimum size.
-  // After this, the buffer is either the default size, or it is empty, so
-  // you have to call EnsureCapacity before using it again.
-  void Reset();
-
-  ThreadLocal thread_local_;
-  Isolate* isolate_;
-
-  friend class ExternalReference;
-  friend class Isolate;
-  friend class RegExpStackScope;
-
-  DISALLOW_COPY_AND_ASSIGN(RegExpStack);
-};
-
-}}  // namespace v8::internal
-
-#endif  // V8_REGEXP_STACK_H_