Add a 'count' field to the DWARF subrange.

The count field is necessary because there isn't a difference between the 'lo'
and 'hi' attributes for a one-element array and a zero-element array. When the
count is '0', we know that this is a zero-element array. When it's >=1, then
it's a normal constant sized array. When it's -1, then the array is unbounded.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169218 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 718e0dc..f5f36e4 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1252,6 +1252,7 @@
   addDIEEntry(DW_Subrange, dwarf::DW_AT_type, dwarf::DW_FORM_ref4, IndexTy);
   uint64_t L = SR.getLo();
   uint64_t H = SR.getHi();
+  int64_t Count = SR.getCount();
 
   // The L value defines the lower bounds which is typically zero for C/C++. The
   // H value is the upper bounds.  Values are 64 bit.  H - L + 1 is the size
@@ -1265,7 +1266,8 @@
   }
   if (L)
     addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, 0, L);
-  addUInt(DW_Subrange, dwarf::DW_AT_upper_bound, 0, H);
+  if (H > 0 || Count != 0)
+    addUInt(DW_Subrange, dwarf::DW_AT_upper_bound, 0, H);
   Buffer.addChild(DW_Subrange);
 }