[regexp] move regexp parser into own files.

src/utils.h

 // 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.
 
 #ifndef V8_UTILS_H_
 #define V8_UTILS_H_
 
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 #include <cmath>
 
 #include "include/v8.h"
 #include "src/allocation.h"
 #include "src/base/bits.h"
 #include "src/base/logging.h"
 #include "src/base/macros.h"
 #include "src/base/platform/platform.h"
 #include "src/globals.h"
 #include "src/list.h"
 #include "src/vector.h"
 
 namespace v8 {
 namespace internal {
 
 // ----------------------------------------------------------------------------
 // General helper functions
 
+// Returns the value (0 .. 15) of a hexadecimal character c.
+// If c is not a legal hexadecimal character, returns a value < 0.
+inline int HexValue(uc32 c) {
+  c -= '0';
+  if (static_cast<unsigned>(c) <= 9) return c;
+  c = (c | 0x20) - ('a' - '0');  // detect 0x11..0x16 and 0x31..0x36.
+  if (static_cast<unsigned>(c) <= 5) return c + 10;
+  return -1;
+}
+
 
 inline int BoolToInt(bool b) { return b ? 1 : 0; }
 
 
 // Same as strcmp, but can handle NULL arguments.
 inline bool CStringEquals(const char* s1, const char* s2) {
   return (s1 == s2) || (s1 != NULL && s2 != NULL && strcmp(s1, s2) == 0);
 }
 
 
@@ skipping 1734 matching lines @@
   uint8_t* ptr = reinterpret_cast<uint8_t*>(p);
   *ptr = c.b[0];
   *(ptr + 1) = c.b[1];
 #endif  // V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_UTILS_H_