Refactor constructImportedEntityDIE(DwarfUnit, DIImportedEntity) to return a DIE rather than inserting it into a specified context.

First of many steps to improve lexical scope construction (to omit
trivial lexical scopes - those without any direct variables). To that
end it's easier not to create imported entities directly into the
lexical scope node, but to build them, then add them if necessary.

llvm-svn: 216838

1 files changed, 13 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 860c7ca9245..1eb8af938a3 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -688,22 +688,23 @@ void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
   DIImportedEntity Module(N);
   assert(Module.Verify());
   if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
-    constructImportedEntityDIE(TheCU, Module, *D);
+    D->addChild(constructImportedEntityDIE(TheCU, Module));
 }
 
 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
                                             const MDNode *N, DIE &Context) {
   DIImportedEntity Module(N);
   assert(Module.Verify());
-  return constructImportedEntityDIE(TheCU, Module, Context);
+  Context.addChild(constructImportedEntityDIE(TheCU, Module));
 }
 
-void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
-                                            const DIImportedEntity &Module,
-                                            DIE &Context) {
+std::unique_ptr<DIE>
+DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
+                                       const DIImportedEntity &Module) {
   assert(Module.Verify() &&
          "Use one of the MDNode * overloads to handle invalid metadata");
-  DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
+  std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
+  TheCU.insertDIE(Module, IMDie.get());
   DIE *EntityDie;
   DIDescriptor Entity = resolve(Module.getEntity());
   if (Entity.isNameSpace())
@@ -714,13 +715,16 @@ void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
     EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
   else
     EntityDie = TheCU.getDIE(Entity);
-  TheCU.addSourceLine(IMDie, Module.getLineNumber(),
+  assert(EntityDie);
+  TheCU.addSourceLine(*IMDie, Module.getLineNumber(),
                       Module.getContext().getFilename(),
                       Module.getContext().getDirectory());
-  TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
+  TheCU.addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
   StringRef Name = Module.getName();
   if (!Name.empty())
-    TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
+    TheCU.addString(*IMDie, dwarf::DW_AT_name, Name);
+
+  return IMDie;
 }
 
 // Emit all Dwarf sections that should come prior to the content. Create