Start converting usages of off_t to other types.

off_t is a type which is used for file offsets.  Even more
specifically, it is only used by a limited number of C APIs that
deal with files.  Any usage of off_t where the variable is not
intended to be used with one of these APIs is a bug, by definition.

This patch corrects some easy mis-uses of off_t, generally by
converting them to lldb::offset_t, but sometimes by using other
types such as size_t, when appropriate.

The use of off_t to represent these offsets has worked fine in
practice on linux-y platforms, since we used _FILE_OFFSET_64 to
guarantee that off_t was a uint64.  On Windows, however,
_FILE_OFFSET_64 is unrecognized, and off_t will always be 32-bit.
So the usage of off_t on Windows actually leads to legitimate bugs.

Reviewed by: Greg Clayton

Differential Revision: http://reviews.llvm.org/D4358

llvm-svn: 212192
diff --git a/lldb/source/Symbol/ObjectFile.cpp b/lldb/source/Symbol/ObjectFile.cpp
index 962ae00..11b5400 100644
--- a/lldb/source/Symbol/ObjectFile.cpp
+++ b/lldb/source/Symbol/ObjectFile.cpp
@@ -439,7 +439,7 @@
 }
 
 size_t
-ObjectFile::GetData (off_t offset, size_t length, DataExtractor &data) const
+ObjectFile::GetData (lldb::offset_t offset, size_t length, DataExtractor &data) const
 {
     // The entire file has already been mmap'ed into m_data, so just copy from there
     // as the back mmap buffer will be shared with shared pointers.
@@ -447,7 +447,7 @@
 }
 
 size_t
-ObjectFile::CopyData (off_t offset, size_t length, void *dst) const
+ObjectFile::CopyData (lldb::offset_t offset, size_t length, void *dst) const
 {
     // The entire file has already been mmap'ed into m_data, so just copy from there
     // Note that the data remains in target byte order.
@@ -456,7 +456,7 @@
 
 
 size_t
-ObjectFile::ReadSectionData (const Section *section, off_t section_offset, void *dst, size_t dst_len) const
+ObjectFile::ReadSectionData (const Section *section, lldb::offset_t section_offset, void *dst, size_t dst_len) const
 {
     // If some other objectfile owns this data, pass this to them.
     if (section->GetObjectFile() != this)
@@ -475,11 +475,11 @@
     }
     else
     {
-        const uint64_t section_file_size = section->GetFileSize();
-        if (section_offset < static_cast<off_t>(section_file_size))
+        const lldb::offset_t section_file_size = section->GetFileSize();
+        if (section_offset < section_file_size)
         {
-            const uint64_t section_bytes_left = section_file_size - section_offset;
-            uint64_t section_dst_len = dst_len;
+            const size_t section_bytes_left = section_file_size - section_offset;
+            size_t section_dst_len = dst_len;
             if (section_dst_len > section_bytes_left)
                 section_dst_len = section_bytes_left;
             return CopyData (section->GetFileOffset() + section_offset, section_dst_len, dst);