diff -r 000000000000 -r 6474c204b198 xpcom/string/public/nsCharTraits.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/string/public/nsCharTraits.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,602 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsCharTraits_h___
+#define nsCharTraits_h___
+
+#include <ctype.h> // for |EOF|, |WEOF|
+#include <string.h> // for |memcpy|, et al
+
+#include "nscore.h" // for |char16_t|
+
+// This file may be used (through nsUTF8Utils.h) from non-XPCOM code, in
+// particular the standalone software updater. In that case stub out
+// the macros provided by nsDebug.h which are only usable when linking XPCOM
+
+#ifdef NS_NO_XPCOM
+#define NS_WARNING(msg)
+#define NS_ASSERTION(cond, msg)
+#define NS_ERROR(msg)
+#else
+#include "nsDebug.h"  // for NS_ASSERTION
+#endif
+
+/*
+ * Some macros for converting char16_t (UTF-16) to and from Unicode scalar
+ * values.
+ *
+ * Note that UTF-16 represents all Unicode scalar values up to U+10FFFF by
+ * using "surrogate pairs". These consist of a high surrogate, i.e. a code
+ * point in the range U+D800 - U+DBFF, and a low surrogate, i.e. a code point
+ * in the range U+DC00 - U+DFFF, like this:
+ *
+ *  U+D800 U+DC00 =  U+10000
+ *  U+D800 U+DC01 =  U+10001
+ *  ...
+ *  U+DBFF U+DFFE = U+10FFFE
+ *  U+DBFF U+DFFF = U+10FFFF
+ *
+ * These surrogate code points U+D800 - U+DFFF are not themselves valid Unicode
+ * scalar values and are not well-formed UTF-16 except as high-surrogate /
+ * low-surrogate pairs.
+ */
+
+#define PLANE1_BASE          uint32_t(0x00010000)
+// High surrogates are in the range 0xD800 -- OxDBFF
+#define NS_IS_HIGH_SURROGATE(u) ((uint32_t(u) & 0xFFFFFC00) == 0xD800)
+// Low surrogates are in the range 0xDC00 -- 0xDFFF
+#define NS_IS_LOW_SURROGATE(u)  ((uint32_t(u) & 0xFFFFFC00) == 0xDC00)
+// Faster than testing NS_IS_HIGH_SURROGATE || NS_IS_LOW_SURROGATE
+#define IS_SURROGATE(u)      ((uint32_t(u) & 0xFFFFF800) == 0xD800)
+
+// Everything else is not a surrogate: 0x000 -- 0xD7FF, 0xE000 -- 0xFFFF
+
+// N = (H - 0xD800) * 0x400 + 0x10000 + (L - 0xDC00)
+// I wonder whether we could somehow assert that H is a high surrogate
+// and L is a low surrogate
+#define SURROGATE_TO_UCS4(h, l) (((uint32_t(h) & 0x03FF) << 10) + \
+                                 (uint32_t(l) & 0x03FF) + PLANE1_BASE)
+
+// Extract surrogates from a UCS4 char
+// Reference: the Unicode standard 4.0, section 3.9
+// Since (c - 0x10000) >> 10 == (c >> 10) - 0x0080 and 
+// 0xD7C0 == 0xD800 - 0x0080,
+// ((c - 0x10000) >> 10) + 0xD800 can be simplified to
+#define H_SURROGATE(c) char16_t(char16_t(uint32_t(c) >> 10) + \
+                                 char16_t(0xD7C0)) 
+// where it's to be noted that 0xD7C0 is not bitwise-OR'd
+// but added.
+
+// Since 0x10000 & 0x03FF == 0, 
+// (c - 0x10000) & 0x03FF == c & 0x03FF so that
+// ((c - 0x10000) & 0x03FF) | 0xDC00 is equivalent to
+#define L_SURROGATE(c) char16_t(char16_t(uint32_t(c) & uint32_t(0x03FF)) | \
+                                 char16_t(0xDC00))
+
+#define IS_IN_BMP(ucs) (uint32_t(ucs) < PLANE1_BASE)
+#define UCS2_REPLACEMENT_CHAR char16_t(0xFFFD)
+
+#define UCS_END uint32_t(0x00110000)
+#define IS_VALID_CHAR(c) ((uint32_t(c) < UCS_END) && !IS_SURROGATE(c))
+#define ENSURE_VALID_CHAR(c) (IS_VALID_CHAR(c) ? (c) : UCS2_REPLACEMENT_CHAR)
+
+template <class CharT> struct nsCharTraits {};
+
+template <>
+struct nsCharTraits<char16_t>
+  {
+    typedef char16_t char_type;
+    typedef uint16_t  unsigned_char_type;
+    typedef char      incompatible_char_type;
+
+    static char_type* const sEmptyBuffer;
+
+    static
+    void
+    assign( char_type& lhs, char_type rhs )
+      {
+        lhs = rhs;
+      }
+
+
+      // integer representation of characters:
+    typedef int int_type;
+
+    static
+    char_type
+    to_char_type( int_type c )
+      {
+        return char_type(c);
+      }
+
+    static
+    int_type
+    to_int_type( char_type c )
+      {
+        return int_type( static_cast<unsigned_char_type>(c) );
+      }
+
+    static
+    bool
+    eq_int_type( int_type lhs, int_type rhs )
+      {
+        return lhs == rhs;
+      }
+
+
+      // |char_type| comparisons:
+
+    static
+    bool
+    eq( char_type lhs, char_type rhs )
+      {
+        return lhs == rhs;
+      }
+
+    static
+    bool
+    lt( char_type lhs, char_type rhs )
+      {
+        return lhs < rhs;
+      }
+
+
+      // operations on s[n] arrays:
+
+    static
+    char_type*
+    move( char_type* s1, const char_type* s2, size_t n )
+      {
+        return static_cast<char_type*>(memmove(s1, s2, n * sizeof(char_type)));
+      }
+
+    static
+    char_type*
+    copy( char_type* s1, const char_type* s2, size_t n )
+      {
+        return static_cast<char_type*>(memcpy(s1, s2, n * sizeof(char_type)));
+      }
+
+    static
+    char_type*
+    copyASCII( char_type* s1, const char* s2, size_t n )
+      {
+        for (char_type* s = s1; n--; ++s, ++s2) {
+          NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+          *s = *s2;
+        }
+        return s1;
+      }
+
+    static
+    char_type*
+    assign( char_type* s, size_t n, char_type c )
+      {
+        char_type* result = s;
+        while ( n-- )
+          assign(*s++, c);
+        return result;
+      }
+
+    static
+    int
+    compare( const char_type* s1, const char_type* s2, size_t n )
+      {
+        for ( ; n--; ++s1, ++s2 )
+          {
+            if ( !eq(*s1, *s2) )
+              return to_int_type(*s1) - to_int_type(*s2);
+          }
+
+        return 0;
+      }
+
+    static
+    int
+    compareASCII( const char_type* s1, const char* s2, size_t n )
+      {
+        for ( ; n--; ++s1, ++s2 )
+          {
+            NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+            if ( !eq_int_type(to_int_type(*s1), to_int_type(*s2)) )
+              return to_int_type(*s1) - to_int_type(*s2);
+          }
+
+        return 0;
+      }
+
+    // this version assumes that s2 is null-terminated and s1 has length n.
+    // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+    // we return 1.
+    static
+    int
+    compareASCIINullTerminated( const char_type* s1, size_t n, const char* s2 )
+      {
+        for ( ; n--; ++s1, ++s2 )
+          {
+            if ( !*s2 )
+              return 1;
+            NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+            if ( !eq_int_type(to_int_type(*s1), to_int_type(*s2)) )
+              return to_int_type(*s1) - to_int_type(*s2);
+          }
+
+        if ( *s2 )
+          return -1;
+
+        return 0;
+      }
+
+    /**
+     * Convert c to its lower-case form, but only if c is in the ASCII
+     * range. Otherwise leave it alone.
+     */
+    static
+    char_type
+    ASCIIToLower( char_type c )
+      {
+        if (c >= 'A' && c <= 'Z')
+          return char_type(c + ('a' - 'A'));
+          
+        return c;
+      }
+
+    static
+    int
+    compareLowerCaseToASCII( const char_type* s1, const char* s2, size_t n )
+      {
+        for ( ; n--; ++s1, ++s2 )
+          {
+            NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+            NS_ASSERTION(!(*s2 >= 'A' && *s2 <= 'Z'),
+                         "Unexpected uppercase character");
+            char_type lower_s1 = ASCIIToLower(*s1);
+            if ( lower_s1 != to_char_type(*s2) )
+              return to_int_type(lower_s1) - to_int_type(*s2);
+          }
+
+        return 0;
+      }
+
+    // this version assumes that s2 is null-terminated and s1 has length n.
+    // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+    // we return 1.
+    static
+    int
+    compareLowerCaseToASCIINullTerminated( const char_type* s1, size_t n, const char* s2 )
+      {
+        for ( ; n--; ++s1, ++s2 )
+          {
+            if ( !*s2 )
+              return 1;
+            NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+            NS_ASSERTION(!(*s2 >= 'A' && *s2 <= 'Z'),
+                         "Unexpected uppercase character");
+            char_type lower_s1 = ASCIIToLower(*s1);
+            if ( lower_s1 != to_char_type(*s2) )
+              return to_int_type(lower_s1) - to_int_type(*s2);
+          }
+
+        if ( *s2 )
+          return -1;
+
+        return 0;
+      }
+
+    static
+    size_t
+    length( const char_type* s )
+      {
+        size_t result = 0;
+        while ( !eq(*s++, char_type(0)) )
+          ++result;
+        return result;
+      }
+
+    static
+    const char_type*
+    find( const char_type* s, size_t n, char_type c )
+      {
+        while ( n-- )
+          {
+            if ( eq(*s, c) )
+              return s;
+            ++s;
+          }
+
+        return 0;
+      }
+  };
+
+template <>
+struct nsCharTraits<char>
+  {
+    typedef char           char_type;
+    typedef unsigned char  unsigned_char_type;
+    typedef char16_t      incompatible_char_type;
+
+    static char_type* const sEmptyBuffer;
+
+    static
+    void
+    assign( char_type& lhs, char_type rhs )
+      {
+        lhs = rhs;
+      }
+
+
+      // integer representation of characters:
+
+    typedef int int_type;
+
+    static
+    char_type
+    to_char_type( int_type c )
+      {
+        return char_type(c);
+      }
+
+    static
+    int_type
+    to_int_type( char_type c )
+      {
+        return int_type( static_cast<unsigned_char_type>(c) );
+      }
+
+    static
+    bool
+    eq_int_type( int_type lhs, int_type rhs )
+      {
+        return lhs == rhs;
+      }
+
+
+      // |char_type| comparisons:
+
+    static
+    bool
+    eq( char_type lhs, char_type rhs )
+      {
+        return lhs == rhs;
+      }
+
+    static
+    bool
+    lt( char_type lhs, char_type rhs )
+      {
+        return lhs < rhs;
+      }
+
+
+      // operations on s[n] arrays:
+
+    static
+    char_type*
+    move( char_type* s1, const char_type* s2, size_t n )
+      {
+        return static_cast<char_type*>(memmove(s1, s2, n * sizeof(char_type)));
+      }
+
+    static
+    char_type*
+    copy( char_type* s1, const char_type* s2, size_t n )
+      {
+        return static_cast<char_type*>(memcpy(s1, s2, n * sizeof(char_type)));
+      }
+
+    static
+    char_type*
+    copyASCII( char_type* s1, const char* s2, size_t n )
+      {
+        return copy(s1, s2, n);
+      }
+
+    static
+    char_type*
+    assign( char_type* s, size_t n, char_type c )
+      {
+        return static_cast<char_type*>(memset(s, to_int_type(c), n));
+      }
+
+    static
+    int
+    compare( const char_type* s1, const char_type* s2, size_t n )
+      {
+        return memcmp(s1, s2, n);
+      }
+
+    static
+    int
+    compareASCII( const char_type* s1, const char* s2, size_t n )
+      {
+#ifdef DEBUG
+        for (size_t i = 0; i < n; ++i)
+          {
+            NS_ASSERTION(!(s2[i] & ~0x7F), "Unexpected non-ASCII character");
+          }
+#endif
+        return compare(s1, s2, n);
+      }
+
+    // this version assumes that s2 is null-terminated and s1 has length n.
+    // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+    // we return 1.
+    static
+    int
+    compareASCIINullTerminated( const char_type* s1, size_t n, const char* s2 )
+      {
+        // can't use strcmp here because we don't want to stop when s1
+        // contains a null
+        for ( ; n--; ++s1, ++s2 )
+          {
+            if ( !*s2 )
+              return 1;
+            NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+            if ( *s1 != *s2 )
+              return to_int_type(*s1) - to_int_type(*s2);
+          }
+
+        if ( *s2 )
+          return -1;
+
+        return 0;
+      }
+
+    /**
+     * Convert c to its lower-case form, but only if c is ASCII.
+     */
+    static
+    char_type
+    ASCIIToLower( char_type c )
+      {
+        if (c >= 'A' && c <= 'Z')
+          return char_type(c + ('a' - 'A'));
+
+        return c;
+      }
+
+    static
+    int
+    compareLowerCaseToASCII( const char_type* s1, const char* s2, size_t n )
+      {
+        for ( ; n--; ++s1, ++s2 )
+          {
+            NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+            NS_ASSERTION(!(*s2 >= 'A' && *s2 <= 'Z'),
+                         "Unexpected uppercase character");
+            char_type lower_s1 = ASCIIToLower(*s1);
+            if ( lower_s1 != *s2 )
+              return to_int_type(lower_s1) - to_int_type(*s2);
+          }
+        return 0;
+      }
+
+    // this version assumes that s2 is null-terminated and s1 has length n.
+    // if s1 is shorter than s2 then we return -1; if s1 is longer than s2,
+    // we return 1.
+    static
+    int
+    compareLowerCaseToASCIINullTerminated( const char_type* s1, size_t n, const char* s2 )
+      {
+        for ( ; n--; ++s1, ++s2 )
+          {
+            if ( !*s2 )
+              return 1;
+            NS_ASSERTION(!(*s2 & ~0x7F), "Unexpected non-ASCII character");
+            NS_ASSERTION(!(*s2 >= 'A' && *s2 <= 'Z'),
+                         "Unexpected uppercase character");
+            char_type lower_s1 = ASCIIToLower(*s1);
+            if ( lower_s1 != *s2 )
+              return to_int_type(lower_s1) - to_int_type(*s2);
+          }
+
+        if ( *s2 )
+          return -1;
+
+        return 0;
+      }
+
+    static
+    size_t
+    length( const char_type* s )
+      {
+        return strlen(s);
+      }
+
+    static
+    const char_type*
+    find( const char_type* s, size_t n, char_type c )
+      {
+        return reinterpret_cast<const char_type*>(memchr(s, to_int_type(c), n));
+      }
+  };
+
+template <class InputIterator>
+struct nsCharSourceTraits
+  {
+    typedef typename InputIterator::difference_type difference_type;
+
+    static
+    uint32_t
+    readable_distance( const InputIterator& first, const InputIterator& last )
+      {
+        // assumes single fragment
+        return uint32_t(last.get() - first.get());
+      }
+
+    static
+    const typename InputIterator::value_type*
+    read( const InputIterator& iter )
+      {
+        return iter.get();
+      }
+
+    static
+    void
+    advance( InputIterator& s, difference_type n )
+      {
+        s.advance(n);
+      }
+  };
+
+template <class CharT>
+struct nsCharSourceTraits<CharT*>
+  {
+    typedef ptrdiff_t difference_type;
+
+    static
+    uint32_t
+    readable_distance( CharT* s )
+      {
+        return uint32_t(nsCharTraits<CharT>::length(s));
+//      return numeric_limits<uint32_t>::max();
+      }
+
+    static
+    uint32_t
+    readable_distance( CharT* first, CharT* last )
+      {
+        return uint32_t(last-first);
+      }
+
+    static
+    const CharT*
+    read( CharT* s )
+      {
+        return s;
+      }
+
+    static
+    void
+    advance( CharT*& s, difference_type n )
+      {
+        s += n;
+      }
+  };
+
+template <class OutputIterator>
+struct nsCharSinkTraits
+  {
+    static
+    void
+    write( OutputIterator& iter, const typename OutputIterator::value_type* s, uint32_t n )
+      {
+        iter.write(s, n);
+      }
+  };
+
+template <class CharT>
+struct nsCharSinkTraits<CharT*>
+  {
+    static
+    void
+    write( CharT*& iter, const CharT* s, uint32_t n )
+      {
+        nsCharTraits<CharT>::move(iter, s, n);
+        iter += n;
+      }
+  };
+
+#endif // !defined(nsCharTraits_h___)