[LLDB] Set the right address size on output DataExtractors from ObjectFile

If filling in a DataExtractor from an ObjectFile, e.g. via the
ReadSectionData method, the output DataExtractor gets the address
size from the m_data member.

ObjectFile's m_data member is initialized without knowledge about
the address size (so the address size is set based on the host's
sizeof(void*), and at that point within ObjectFile's constructor,
virtual methods implemented in subclasses (like GetAddressByteSize())
can't be called, therefore fix it up when filling in external
DataExtractors.

This makes sure that line tables from executables with a different
address size are parsed properly; previously this tripped up
DWARFDebugLine::LineTable::parse for 32 bit executables on a 64 bit
host, as the address size in the line table (4) didn't match the
one set in the DWARFDataExtractor.

Differential Revision: https://reviews.llvm.org/D70848

1 files changed, 7 insertions, 1 deletions

diff --git a/lldb/source/Symbol/ObjectFile.cpp b/lldb/source/Symbol/ObjectFile.cpp
index 4f6d74bbc75..812c6de4da5 100644
--- a/lldb/source/Symbol/ObjectFile.cpp
+++ b/lldb/source/Symbol/ObjectFile.cpp
@@ -477,7 +477,13 @@ size_t 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.
-  return data.SetData(m_data, offset, length);
+  size_t ret = data.SetData(m_data, offset, length);
+  // DataExtractor::SetData copies the address byte size from m_data, but
+  // m_data's address byte size is only set from sizeof(void*), and we can't
+  // access subclasses GetAddressByteSize() when setting up m_data in the
+  // constructor.
+  data.SetAddressByteSize(GetAddressByteSize());
+  return ret;
 }
 
 size_t ObjectFile::CopyData(lldb::offset_t offset, size_t length,