Elaborate on comment for skeleton CU construction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198358 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index a1e415a1bd74498882ecf2a3d59be1961e212b2f..44163d20f4c1114aa31233240e88197d1e1e7881 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -825,7 +825,10 @@ DwarfCompileUnit *DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
   if (useSplitDwarf()) {
     NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
                        DwarfInfoDWOSectionSym);
-    // If we're splitting the dwarf then construct the skeleton CU now.
+    // If we're splitting the dwarf then construct the skeleton CU now
+    // since we'll need to be able to reference the symbols in the skeleton
+    // CU during various emission passes - in particular aranges need
+    // to reference the skeleton CU.
     NewCU->setSkeleton(constructSkeletonCU(NewCU));
   } else
     NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),