DebugInfo: Support debug_loc under fission

Implement debug_loc.dwo, as well as llvm-dwarfdump support for dumping
this section.

Outlined in the DWARF5 spec and http://gcc.gnu.org/wiki/DebugFission the
debug_loc.dwo section has more variation than the standard debug_loc,
allowing 3 different forms of entry (plus the end of list entry). GCC
seems to, and Clang certainly, only use one form, so I've just
implemented dumping support for that for now.

It wasn't immediately obvious that there was a good refactoring to share
the implementation of dumping support between debug_loc and
debug_loc.dwo, so they're separate for now - ideas welcome or I may come
back to it at some point.

As per a comment in the code, we could choose different forms that may
reduce the number of debug_addr entries we emit, but that will require
further study.

llvm-svn: 204697

2 files changed, 9 insertions, 0 deletions

diff --git a/llvm/include/llvm/DebugInfo/DIContext.h b/llvm/include/llvm/DebugInfo/DIContext.h
index f04dc001f4b..69a4f8d1f6b 100644
--- a/llvm/include/llvm/DebugInfo/DIContext.h
+++ b/llvm/include/llvm/DebugInfo/DIContext.h
@@ -109,6 +109,7 @@ enum DIDumpType {
   DIDT_Line,
   DIDT_LineDwo,
   DIDT_Loc,
+  DIDT_LocDwo,
   DIDT_Ranges,
   DIDT_Pubnames,
   DIDT_Pubtypes,
diff --git a/llvm/include/llvm/Support/Dwarf.h b/llvm/include/llvm/Support/Dwarf.h
index 7d434dcb12d..87696990600 100644
--- a/llvm/include/llvm/Support/Dwarf.h
+++ b/llvm/include/llvm/Support/Dwarf.h
@@ -771,6 +771,14 @@ enum Constants {
   DW_EH_PE_indirect = 0x80
 };
 
+enum LocationListEntry : unsigned char {
+  DW_LLE_end_of_list_entry,
+  DW_LLE_base_address_selection_entry,
+  DW_LLE_start_end_entry,
+  DW_LLE_start_length_entry,
+  DW_LLE_offset_pair_entry
+};
+
 enum ApplePropertyAttributes {
   // Apple Objective-C Property Attributes
   DW_APPLE_PROPERTY_readonly = 0x01,