diff options
| -rw-r--r-- | src/pugixml.cpp | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/src/pugixml.cpp b/src/pugixml.cpp index 16190c6..dd7ce21 100644 --- a/src/pugixml.cpp +++ b/src/pugixml.cpp @@ -423,6 +423,15 @@ PUGI__NS_BEGIN static const uintptr_t xml_memory_page_value_allocated_or_shared_mask = xml_memory_page_value_allocated_mask | xml_memory_page_contents_shared_mask; static const uintptr_t xml_memory_page_contents_allocated_or_shared_mask = xml_memory_page_contents_allocated_mask | xml_memory_page_contents_shared_mask; + // all allocated blocks have a certain guaranteed alignment + static const uintptr_t xml_memory_block_alignment = + #ifdef PUGIXML_COMPACT + 4 + #else + sizeof(void*) + #endif + ; + #define PUGI__NODETYPE(n) static_cast<xml_node_type>(((n)->header & impl::xml_memory_page_type_mask) + 1) struct xml_allocator; @@ -559,15 +568,15 @@ PUGI__NS_BEGIN char_t* allocate_string(size_t length) { - static const size_t max_encoded_offset = (1 << 16) * sizeof(void*); + static const size_t max_encoded_offset = (1 << 16) * xml_memory_block_alignment; PUGI__STATIC_ASSERT(xml_memory_page_size <= max_encoded_offset); // allocate memory for string and header block size_t size = sizeof(xml_memory_string_header) + length * sizeof(char_t); - // round size up to pointer alignment boundary - size_t full_size = (size + (sizeof(void*) - 1)) & ~(sizeof(void*) - 1); + // round size up to block alignment boundary + size_t full_size = (size + (xml_memory_block_alignment - 1)) & ~(xml_memory_block_alignment - 1); xml_memory_page* page; xml_memory_string_header* header = static_cast<xml_memory_string_header*>(allocate_memory(full_size, page)); @@ -577,14 +586,14 @@ PUGI__NS_BEGIN // setup header ptrdiff_t page_offset = reinterpret_cast<char*>(header) - reinterpret_cast<char*>(page) - sizeof(xml_memory_page); - assert(page_offset % sizeof(void*) == 0); + assert(page_offset % xml_memory_block_alignment == 0); assert(page_offset >= 0 && static_cast<size_t>(page_offset) < max_encoded_offset); - header->page_offset = static_cast<uint16_t>(static_cast<size_t>(page_offset) / sizeof(void*)); + header->page_offset = static_cast<uint16_t>(static_cast<size_t>(page_offset) / xml_memory_block_alignment); // full_size == 0 for large strings that occupy the whole page - assert(full_size % sizeof(void*) == 0); + assert(full_size % xml_memory_block_alignment == 0); assert(full_size < max_encoded_offset || (page->busy_size == full_size && page_offset == 0)); - header->full_size = static_cast<uint16_t>(full_size < max_encoded_offset ? full_size / sizeof(void*) : 0); + header->full_size = static_cast<uint16_t>(full_size < max_encoded_offset ? full_size / xml_memory_block_alignment : 0); // round-trip through void* to avoid 'cast increases required alignment of target type' warning // header is guaranteed a pointer-sized alignment, which should be enough for char_t @@ -601,11 +610,11 @@ PUGI__NS_BEGIN assert(header); // deallocate - size_t page_offset = sizeof(xml_memory_page) + header->page_offset * sizeof(void*); + size_t page_offset = sizeof(xml_memory_page) + header->page_offset * xml_memory_block_alignment; xml_memory_page* page = reinterpret_cast<xml_memory_page*>(static_cast<void*>(reinterpret_cast<char*>(header) - page_offset)); // if full_size == 0 then this string occupies the whole page - size_t full_size = header->full_size == 0 ? page->busy_size : header->full_size * sizeof(void*); + size_t full_size = header->full_size == 0 ? page->busy_size : header->full_size * xml_memory_block_alignment; deallocate_memory(header, full_size, page); } @@ -677,6 +686,7 @@ PUGI__NS_BEGIN public: compact_header(xml_memory_page* page, unsigned int flags) { + PUGI__STATIC_ASSERT(xml_memory_block_alignment == compact_alignment); PUGI__STATIC_ASSERT(sizeof(xml_memory_page) + xml_memory_page_size <= (1 << (16 + compact_alignment_log2))); ptrdiff_t page_offset = (reinterpret_cast<char*>(this) - reinterpret_cast<char*>(page)) >> compact_alignment_log2; |