DebugInfo: Ensure imported entities at the top level of an inlined function don't cause degenerate concrete definitions

Local imported entities at the top level of a subprogram were being
handled differently from those in nested scopes - that different
handling would cause pseudo concrete out-of-line definitions to be
created (but without any of their attributes, nor an abstract_origin) in
the case where there was no real concrete definition.

These local imported entities also only appeared in the concrete
definition where those imported entities in nested scopes appear in all
cases (abstract, concrete, and inlined). This change at least makes top
level case handle the same as the others - though there's a FIXME to
improve this to /only/ emit them into the abstract origin (though this
requires more plumbing - like the abstract subprogram and variable
handling that must defer population until the end of the unit to
discover if there is an abstract origin, or only a standalone concrete
definition).

llvm-svn: 309237

3 files changed, 18 insertions, 17 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 676c48fe5c6..e4b8939f2ab 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -336,23 +336,15 @@ void DwarfCompileUnit::constructScopeDIE(
     if (DD->isLexicalScopeDIENull(Scope))
       return;
 
-    unsigned ChildScopeCount;
+    bool HasNonScopeChildren = false;
 
     // We create children here when we know the scope DIE is not going to be
     // null and the children will be added to the scope DIE.
-    createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
-
-    // Skip imported directives in gmlt-like data.
-    if (!includeMinimalInlineScopes()) {
-      // There is no need to emit empty lexical block DIE.
-      for (const auto *IE : ImportedEntities[DS])
-        Children.push_back(
-            constructImportedEntityDIE(cast<DIImportedEntity>(IE)));
-    }
+    createScopeChildrenDIE(Scope, Children, &HasNonScopeChildren);
 
     // If there are only other scopes as children, put them directly in the
     // parent instead, as this scope would serve no purpose.
-    if (Children.size() == ChildScopeCount) {
+    if (!HasNonScopeChildren) {
       FinalChildren.insert(FinalChildren.end(),
                            std::make_move_iterator(Children.begin()),
                            std::make_move_iterator(Children.end()));
@@ -557,20 +549,27 @@ DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
 
 DIE *DwarfCompileUnit::createScopeChildrenDIE(LexicalScope *Scope,
                                               SmallVectorImpl<DIE *> &Children,
-                                              unsigned *ChildScopeCount) {
+                                              bool *HasNonScopeChildren) {
+  assert(Children.empty());
   DIE *ObjectPointer = nullptr;
 
   for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
     Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
 
-  unsigned ChildCountWithoutScopes = Children.size();
+  // Skip imported directives in gmlt-like data.
+  if (!includeMinimalInlineScopes()) {
+    // There is no need to emit empty lexical block DIE.
+    for (const auto *IE : ImportedEntities[Scope->getScopeNode()])
+      Children.push_back(
+          constructImportedEntityDIE(cast<DIImportedEntity>(IE)));
+  }
+
+  if (HasNonScopeChildren)
+    *HasNonScopeChildren = !Children.empty();
 
   for (LexicalScope *LS : Scope->getChildren())
     constructScopeDIE(LS, Children);
 
-  if (ChildScopeCount)
-    *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
-
   return ObjectPointer;
 }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index e3867279286..93b3504d9f0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -181,7 +181,7 @@ public:
   /// A helper function to create children of a Scope DIE.
   DIE *createScopeChildrenDIE(LexicalScope *Scope,
                               SmallVectorImpl<DIE *> &Children,
-                              unsigned *ChildScopeCount = nullptr);
+                              bool *HasNonScopeChildren = nullptr);
 
   /// \brief Construct a DIE for this subprogram scope.
   void constructSubprogramScopeDIE(const DISubprogram *Sub, LexicalScope *Scope);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 70fe1e233ba..d2085e34190 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -494,6 +494,8 @@ DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) {
 
 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
                                                   const DIImportedEntity *N) {
+  if (isa<DILocalScope>(N->getScope()))
+    return;
   if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
     D->addChild(TheCU.constructImportedEntityDIE(N));
 }