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.

llvm-svn: 169218

2 files changed, 7 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 718e0dceb06..f5f36e461f1 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1252,6 +1252,7 @@ void CompileUnit::constructSubrangeDIE(DIE &Buffer, DISubrange SR,
   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 @@ void CompileUnit::constructSubrangeDIE(DIE &Buffer, DISubrange SR,
   }
   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);
 }
 
diff --git a/llvm/lib/VMCore/DIBuilder.cpp b/llvm/lib/VMCore/DIBuilder.cpp
index 74b69e46172..2b77edc7f99 100644
--- a/llvm/lib/VMCore/DIBuilder.cpp
+++ b/llvm/lib/VMCore/DIBuilder.cpp
@@ -741,11 +741,13 @@ DIArray DIBuilder::getOrCreateArray(ArrayRef<Value *> Elements) {
 
 /// getOrCreateSubrange - Create a descriptor for a value range.  This
 /// implicitly uniques the values returned.
-DISubrange DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Hi) {
+DISubrange DIBuilder::getOrCreateSubrange(int64_t Lo, int64_t Hi,
+                                          int64_t Count) {
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_subrange_type),
     ConstantInt::get(Type::getInt64Ty(VMContext), Lo),
-    ConstantInt::get(Type::getInt64Ty(VMContext), Hi)
+    ConstantInt::get(Type::getInt64Ty(VMContext), Hi),
+    ConstantInt::get(Type::getInt64Ty(VMContext), Count)
   };
 
   return DISubrange(MDNode::get(VMContext, Elts));