Function expat_malloc

Utilities/cmexpat/lib/xmlparse.c:850–899

void *
#  else
static void *
#  endif
expat_malloc(XML_Parser parser, size_t size, int sourceLine) {
  // Detect integer overflow
  if (SIZE_MAX - size < sizeof(size_t) + EXPAT_MALLOC_PADDING) {
    return NULL;
  }

  const XML_Parser rootParser = getRootParserOf(parser, NULL);
  assert(rootParser->m_parentParser == NULL);

  const size_t bytesToAllocate = sizeof(size_t) + EXPAT_MALLOC_PADDING + size;

  if ((XmlBigCount)-1 - rootParser->m_alloc_tracker.bytesAllocated
      < bytesToAllocate) {
    return NULL; // i.e. signal integer overflow as out-of-memory
  }

  if (! expat_heap_increase_tolerable(rootParser, bytesToAllocate,
                                      sourceLine)) {
    return NULL; // i.e. signal violation as out-of-memory
  }

  // Actually allocate
  void *const mallocedPtr = parser->m_mem.malloc_fcn(bytesToAllocate);

  if (mallocedPtr == NULL) {
    return NULL;
  }

  // Update in-block recorded size
  *(size_t *)mallocedPtr = size;

  // Update accounting
  rootParser->m_alloc_tracker.bytesAllocated += bytesToAllocate;

  // Report as needed
  if (rootParser->m_alloc_tracker.debugLevel >= 2) {
    if (rootParser->m_alloc_tracker.bytesAllocated
        > rootParser->m_alloc_tracker.peakBytesAllocated) {
      rootParser->m_alloc_tracker.peakBytesAllocated
          = rootParser->m_alloc_tracker.bytesAllocated;
    }
    expat_heap_stat(rootParser, '+', bytesToAllocate,
                    rootParser->m_alloc_tracker.bytesAllocated,
                    rootParser->m_alloc_tracker.peakBytesAllocated, sourceLine);
  }

  return (char *)mallocedPtr + sizeof(size_t) + EXPAT_MALLOC_PADDING;
}

#  if defined(XML_TESTING)
void