1 files changed, 26 insertions, 20 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index f1ae89e93a..a30e8bbd95 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -773,6 +773,12 @@ DwarfCompileUnit *DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
                  DIUnit.getLanguage());
   NewCU->addString(Die, dwarf::DW_AT_name, FN);
 
+  // 2.17.1 requires that we use DW_AT_low_pc for a single entry point
+  // into an entity. We're using 0 (or a NULL label) for this. For
+  // split dwarf it's in the skeleton CU so omit it here.
+  if (!useSplitDwarf())
+    NewCU->addLabelAddress(Die, dwarf::DW_AT_low_pc, NULL);
+
   // Define start line table label for each Compile Unit.
   MCSymbol *LineTableStartSym =
       Asm->GetTempSymbol("line_table_start", NewCU->getUniqueID());
@@ -831,10 +837,6 @@ DwarfCompileUnit *DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
       // skeleton units, not full units, if it's going to reference skeletons
       DwarfInfoSectionSym);
 
-  // If we're splitting the dwarf then construct the skeleton CU now.
-  if (useSplitDwarf())
-    NewCU->setSkeleton(constructSkeletonCU(NewCU));
-
   CUMap.insert(std::make_pair(DIUnit, NewCU));
   CUDieMap.insert(std::make_pair(Die, NewCU));
   return NewCU;
@@ -1080,9 +1082,7 @@ void DwarfDebug::finalizeModuleInfo() {
     // Add CU specific attributes if we need to add any.
     if (TheU->getUnitDie()->getTag() == dwarf::DW_TAG_compile_unit) {
       // If we're splitting the dwarf out now that we've got the entire
-      // CU then add the dwo id to it.
-      DwarfCompileUnit *SkCU =
-          static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
+      // CU then construct a skeleton CU based upon it.
       if (useSplitDwarf()) {
         // This should be a unique identifier when we want to build .dwp files.
         uint64_t ID = 0;
@@ -1092,22 +1092,19 @@ void DwarfDebug::finalizeModuleInfo() {
         }
         TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
                       dwarf::DW_FORM_data8, ID);
+        // Now construct the skeleton CU associated.
+        DwarfCompileUnit *SkCU =
+            constructSkeletonCU(static_cast<DwarfCompileUnit *>(TheU));
         SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
                       dwarf::DW_FORM_data8, ID);
+      } else {
+        // Attribute if we've emitted a range list for the compile unit, this
+        // will get constructed for the skeleton CU separately if we have one.
+        if (DwarfCURanges && TheU->getRanges().size())
+          addSectionLabel(Asm, TheU, TheU->getUnitDie(), dwarf::DW_AT_ranges,
+                          Asm->GetTempSymbol("cu_ranges", TheU->getUniqueID()),
+                          DwarfDebugRangeSectionSym);
       }
-
-      // If we've requested ranges and have them emit a DW_AT_ranges attribute
-      // on the unit that will remain in the .o file, otherwise add a DW_AT_low_pc.
-      // FIXME: Also add a high pc if we can.
-      // FIXME: We should use ranges if we have multiple compile units.
-      DwarfCompileUnit *U = SkCU ? SkCU : static_cast<DwarfCompileUnit *>(TheU);
-      if (DwarfCURanges && TheU->getRanges().size())
-        addSectionLabel(Asm, U, U->getUnitDie(), dwarf::DW_AT_ranges,
-                        Asm->GetTempSymbol("cu_ranges", U->getUniqueID()),
-                        DwarfDebugRangeSectionSym);
-      else
-        U->addLocalLabelAddress(U->getUnitDie(), dwarf::DW_AT_low_pc,
-                                TextSectionSym);
     }
   }
 
@@ -3000,6 +2997,15 @@ DwarfCompileUnit *DwarfDebug::constructSkeletonCU(const DwarfCompileUnit *CU) {
   else
     NewCU->addSectionOffset(Die, dwarf::DW_AT_GNU_addr_base, 0);
 
+  // Attribute if we've emitted a range list for the compile unit, this
+  // will get constructed for the skeleton CU separately if we have one.
+  if (DwarfCURanges && CU->getRanges().size())
+    addSectionLabel(Asm, NewCU, Die, dwarf::DW_AT_ranges,
+                    Asm->GetTempSymbol("cu_ranges", CU->getUniqueID()),
+                    DwarfDebugRangeSectionSym);
+  else
+    NewCU->addUInt(Die, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
+
   // DW_AT_stmt_list is a offset of line number information for this
   // compile unit in debug_line section.
   // FIXME: Should handle multiple compile units.