DebugInfo: Ensure unit IDs (for non-skeletal units) match thein index in the list

This simplifies reasoning about the code and enables simple navigation
from a skeleton to its full unit. (currently there are no type unit
skeletons, so the skeleton list doesn't have the same ID == index
property)

Eventually we should get rid of this ID and just store the labels we
need as the IDs are allowing this code to create difficult to
manage/understand associations (loops over non-skeletal units are
implicitly referencing their skeletal units during pub* emission, for
example). It may be necessary to have some kind of skeleton->full unit
association and a more direct pointer or similar device would be
preferable than an index.

llvm-svn: 196600
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index dffd4e0..7d780d1 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -179,7 +179,7 @@
 
 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
     : Asm(A), MMI(Asm->MMI), FirstCU(0), SourceIdMap(DIEValueAllocator),
-      PrevLabel(NULL), GlobalCUIndexCount(0), GlobalRangeCount(0),
+      PrevLabel(NULL), GlobalRangeCount(0),
       InfoHolder(A, "info_string", DIEValueAllocator),
       SkeletonHolder(A, "skel_string", DIEValueAllocator) {
 
@@ -747,8 +747,10 @@
   CompilationDir = DIUnit.getDirectory();
 
   DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
-  CompileUnit *NewCU = new CompileUnit(GlobalCUIndexCount++, Die, DIUnit, Asm,
-                                       this, &InfoHolder);
+  CompileUnit *NewCU = new CompileUnit(InfoHolder.getUnits().size(), Die,
+                                       DIUnit, Asm, this, &InfoHolder);
+  InfoHolder.addUnit(NewCU);
+
 
   FileIDCUMap[NewCU->getUniqueID()] = 0;
   // Call this to emit a .file directive if it wasn't emitted for the source
@@ -816,8 +818,6 @@
   if (!FirstCU)
     FirstCU = NewCU;
 
-  InfoHolder.addUnit(NewCU);
-
   CUMap.insert(std::make_pair(DIUnit, NewCU));
   CUDieMap.insert(std::make_pair(Die, NewCU));
   return NewCU;
@@ -3048,8 +3048,10 @@
     }
   } else {
     DIE *UnitDie = new DIE(dwarf::DW_TAG_type_unit);
-    TypeUnit *NewTU = new TypeUnit(GlobalCUIndexCount++, UnitDie, Language, Asm,
-                                   this, &InfoHolder);
+    TypeUnit *NewTU = new TypeUnit(InfoHolder.getUnits().size(), UnitDie,
+                                   Language, Asm, this, &InfoHolder);
+    InfoHolder.addUnit(NewTU);
+
     NewTU->addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
                    Language);
 
@@ -3077,8 +3079,6 @@
     // Remove the References vector and add the type hash.
     I->second.first = Signature;
     I->second.second = NULL;
-
-    InfoHolder.addUnit(NewTU);
   }
 
   // Populate all the signatures.