1 files changed, 67 insertions, 20 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 4ca42283dd..f0ea8893ca 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -13,28 +13,28 @@
 
 #define DEBUG_TYPE "dwarfdebug"
 
-#include "DwarfAccelTable.h"
 #include "DwarfCompileUnit.h"
+#include "DwarfAccelTable.h"
 #include "DwarfDebug.h"
+#include "llvm/ADT/APFloat.h"
 #include "llvm/Constants.h"
 #include "llvm/DIBuilder.h"
+#include "llvm/DataLayout.h"
 #include "llvm/GlobalVariable.h"
 #include "llvm/Instructions.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Target/Mangler.h"
-#include "llvm/DataLayout.h"
 #include "llvm/Target/TargetFrameLowering.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/ADT/APFloat.h"
-#include "llvm/Support/ErrorHandling.h"
 
 using namespace llvm;
 
 /// CompileUnit - Compile unit constructor.
-CompileUnit::CompileUnit(unsigned I, unsigned L, DIE *D, AsmPrinter *A,
+CompileUnit::CompileUnit(unsigned UID, unsigned L, DIE *D, AsmPrinter *A,
                          DwarfDebug *DW)
-  : ID(I), Language(L), CUDie(D), Asm(A), DD(DW), IndexTyDie(0) {
+  : UniqueID(UID), Language(L), CUDie(D), Asm(A), DD(DW), IndexTyDie(0) {
   DIEIntegerOne = new (DIEValueAllocator) DIEInteger(1);
 }
 
@@ -51,6 +51,50 @@ DIEEntry *CompileUnit::createDIEEntry(DIE *Entry) {
   return Value;
 }
 
+/// getDefaultLowerBound - Return the default lower bound for an array. If the
+/// DWARF version doesn't handle the language, return -1.
+int64_t CompileUnit::getDefaultLowerBound() const {
+  switch (Language) {
+  default:
+    break;
+
+  case dwarf::DW_LANG_C89:
+  case dwarf::DW_LANG_C99:
+  case dwarf::DW_LANG_C:
+  case dwarf::DW_LANG_C_plus_plus:
+  case dwarf::DW_LANG_ObjC:
+  case dwarf::DW_LANG_ObjC_plus_plus:
+    return 0;
+
+  case dwarf::DW_LANG_Fortran77:
+  case dwarf::DW_LANG_Fortran90:
+  case dwarf::DW_LANG_Fortran95:
+    return 1;
+
+  // The languages below have valid values only if the DWARF version >= 4.
+  case dwarf::DW_LANG_Java:
+  case dwarf::DW_LANG_Python:
+  case dwarf::DW_LANG_UPC:
+  case dwarf::DW_LANG_D:
+    if (dwarf::DWARF_VERSION >= 4)
+      return 0;
+    break;
+
+  case dwarf::DW_LANG_Ada83:
+  case dwarf::DW_LANG_Ada95:
+  case dwarf::DW_LANG_Cobol74:
+  case dwarf::DW_LANG_Cobol85:
+  case dwarf::DW_LANG_Modula2:
+  case dwarf::DW_LANG_Pascal83:
+  case dwarf::DW_LANG_PLI:
+    if (dwarf::DWARF_VERSION >= 4)
+      return 1;
+    break;
+  }
+
+  return -1;
+}
+
 /// addFlag - Add a flag that is true.
 void CompileUnit::addFlag(DIE *Die, unsigned Attribute) {
   if (!DD->useDarwinGDBCompat())
@@ -1250,22 +1294,25 @@ void CompileUnit::constructSubrangeDIE(DIE &Buffer, DISubrange SR,
                                        DIE *IndexTy) {
   DIE *DW_Subrange = new DIE(dwarf::DW_TAG_subrange_type);
   addDIEEntry(DW_Subrange, dwarf::DW_AT_type, dwarf::DW_FORM_ref4, IndexTy);
-  uint64_t L = SR.getLo();
-  uint64_t H = SR.getHi();
 
-  // 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
-  // of the array. If L > H then do not emit DW_AT_lower_bound and
-  // DW_AT_upper_bound attributes. If L is zero and H is also zero then the
-  // array has one element and in such case do not emit lower bound.
+  // The LowerBound value defines the lower bounds which is typically zero for
+  // C/C++. The Count value is the number of elements.  Values are 64 bit. If
+  // Count == -1 then the array is unbounded and we do not emit
+  // DW_AT_lower_bound and DW_AT_upper_bound attributes. If LowerBound == 0 and
+  // Count == 0, then the array has zero elements in which case we do not emit
+  // an upper bound.
+  int64_t LowerBound = SR.getLo();
+  int64_t DefaultLowerBound = getDefaultLowerBound();
+  int64_t Count = SR.getCount();
+
+  if (DefaultLowerBound == -1 || LowerBound != DefaultLowerBound)
+    addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, 0, LowerBound);
+
+  if (Count != -1 && Count != 0)
+    // FIXME: An unbounded array should reference the expression that defines
+    // the array.
+    addUInt(DW_Subrange, dwarf::DW_AT_upper_bound, 0, LowerBound + Count - 1);
 
-  if (L > H) {
-    Buffer.addChild(DW_Subrange);
-    return;
-  }
-  if (L)
-    addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, 0, L);
-  addUInt(DW_Subrange, dwarf::DW_AT_upper_bound, 0, H);
   Buffer.addChild(DW_Subrange);
 }