On Windows MapViewOfFile requires the offset to be aligned on the system dwAllocationGranularity

llvm-svn: 191447

1 files changed, 28 insertions, 8 deletions

diff --git a/lldb/source/Core/DataBufferMemoryMap.cpp b/lldb/source/Core/DataBufferMemoryMap.cpp
index 374834a00e0..008b736ef72 100644
--- a/lldb/source/Core/DataBufferMemoryMap.cpp
+++ b/lldb/source/Core/DataBufferMemoryMap.cpp
@@ -147,7 +147,17 @@ DataBufferMemoryMap::MemoryMapFromFileSpec (const FileSpec* filespec,
     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::MemoryMapFromFileDescriptor (int fd,
             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);
             }
         }