[Lldb-commits] [lldb] r191447 - On Windows MapViewOfFile requires the offset to be aligned on the system dwAllocationGranularity

[Carlo Kok]

Author: carlokok
Date: Thu Sep 26 13:52:08 2013
New Revision: 191447

URL: http://llvm.org/viewvc/llvm-project?rev=191447&view=rev
Log:
On Windows MapViewOfFile requires the offset to be aligned on the system dwAllocationGranularity

Modified:
    lldb/trunk/source/Core/DataBufferMemoryMap.cpp

Modified: lldb/trunk/source/Core/DataBufferMemoryMap.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Core/DataBufferMemoryMap.cpp?rev=191447&r1=191446&r2=191447&view=diff
==============================================================================
--- lldb/trunk/source/Core/DataBufferMemoryMap.cpp (original)
+++ lldb/trunk/source/Core/DataBufferMemoryMap.cpp Thu Sep 26 13:52:08 2013
@@ -147,7 +147,17 @@ DataBufferMemoryMap::MemoryMapFromFileSp
     Clear();
     return 0;
 }
-
+
+
+#ifdef _WIN32
+static size_t win32memmapalignment = 0;
+void LoadWin32MemMapAlignment ()
+{
+  SYSTEM_INFO data;
+  GetSystemInfo(&data);
+  win32memmapalignment = data.dwAllocationGranularity;
+}
+#endif
 
 //----------------------------------------------------------------------
 // The file descriptor FD is assumed to already be opened as read only
@@ -206,13 +216,23 @@ DataBufferMemoryMap::MemoryMapFromFileDe
             HANDLE fileMapping = CreateFileMapping(handle, NULL, writeable ? PAGE_READWRITE : PAGE_READONLY, file_size_high, file_size_low, NULL);
             if (fileMapping != NULL)
             {
-                m_mmap_addr = (uint8_t*)MapViewOfFile(fileMapping, writeable ? FILE_MAP_ALL_ACCESS : FILE_MAP_READ, (DWORD)(offset >> 32), (DWORD)(offset), length);
-                if (m_mmap_addr != NULL)
-                {
-                    m_mmap_size = length;
-                    m_data = m_mmap_addr;
-                    m_size = length;
-                }
+                if (win32memmapalignment == 0) LoadWin32MemMapAlignment();
+                lldb::offset_t realoffset = offset;
+                lldb::offset_t delta = 0;
+                if (realoffset % win32memmapalignment != 0) {
+                  realoffset = realoffset / win32memmapalignment * win32memmapalignment;
+                  delta = offset - realoffset;
+	              }
+
+                LPVOID data = MapViewOfFile(fileMapping, writeable ? FILE_MAP_WRITE : FILE_MAP_READ, 0, realoffset, length + delta);
+                m_mmap_addr = (uint8_t *)data;
+                if (!data) {
+                  Error error; 
+                  error.SetErrorToErrno ();
+                } else {
+                  m_data = m_mmap_addr + delta;
+                  m_size = length;
+                }
                 CloseHandle(fileMapping);
             }
         }