intl/lwbrk/nsUniscribeBreaker.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsComplexBreaker.h"
   7
   8 #include <windows.h>
   9
  10 #include <usp10.h>
  11
  12 #include "nsUTF8Utils.h"
  13 #include "nsString.h"
  14 #include "nsTArray.h"
  15
  16 #if defined(NIGHTLY_BUILD)
  17 #  include "mozilla/WindowsProcessMitigations.h"
  18 #  define TH_UNICODE
  19 #  include "rulebrk.h"
  20 #endif
  21
  22 void NS_GetComplexLineBreaks(const char16_t* aText, uint32_t aLength,
  23                              uint8_t* aBreakBefore) {
  24   NS_ASSERTION(aText, "aText shouldn't be null");
  25
  26 #if defined(NIGHTLY_BUILD)
  27   // If win32k lockdown is enabled we can't use Uniscribe, so fall back to
  28   // nsRuleBreaker code. This will lead to some regressions and the change is
  29   // only to allow testing of win32k lockdown in content.
  30   // Use of Uniscribe will be replaced in bug 1684927.
  31   if (mozilla::IsWin32kLockedDown()) {
  32     for (uint32_t i = 0; i < aLength; i++)
  33       aBreakBefore[i] =
  34           (0 == TrbWordBreakPos(aText, i, aText + i, aLength - i));
  35     return;
  36   }
  37 #endif
  38
  39   int outItems = 0;
  40   HRESULT result;
  41   AutoTArray<SCRIPT_ITEM, 64> items;
  42   char16ptr_t text = aText;
  43
  44   memset(aBreakBefore, false, aLength);
  45
  46   items.AppendElements(64);
  47
  48   do {
  49     result = ScriptItemize(text, aLength, items.Length(), nullptr, nullptr,
  50                            items.Elements(), &outItems);
  51
  52     if (result == E_OUTOFMEMORY) {
  53       // XXX(Bug 1631371) Check if this should use a fallible operation as it
  54       // pretended earlier.
  55       items.AppendElements(items.Length());
  56     }
  57   } while (result == E_OUTOFMEMORY);
  58
  59   for (int iItem = 0; iItem < outItems; ++iItem) {
  60     uint32_t endOffset =
  61         (iItem + 1 == outItems ? aLength : items[iItem + 1].iCharPos);
  62     uint32_t startOffset = items[iItem].iCharPos;
  63     AutoTArray<SCRIPT_LOGATTR, 64> sla;
  64
  65     // XXX(Bug 1631371) Check if this should use a fallible operation as it
  66     // pretended earlier.
  67     sla.AppendElements(endOffset - startOffset);
  68
  69     if (ScriptBreak(text + startOffset, endOffset - startOffset,
  70                     &items[iItem].a, sla.Elements()) < 0)
  71       return;
  72
  73     // We don't want to set a potential break position at the start of text;
  74     // that's the responsibility of a higher level.
  75     for (uint32_t j = startOffset ? 0 : 1; j + startOffset < endOffset; ++j) {
  76       aBreakBefore[j + startOffset] = sla[j].fSoftBreak;
  77     }
  78   }
  79 }