Implement DR1460: fix handling of default initializers in unions; don't allow

more than one such initializer in a union, make mem-initializers override
default initializers for other union members, handle anonymous unions with
anonymous struct members better. Fix a couple of semi-related bugs exposed by
the tests for same.

llvm-svn: 196892

1 files changed, 12 insertions, 14 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 8efdffaf090..fc3eeb86306 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -11184,37 +11184,34 @@ void Sema::MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func) {
 
   // Note that this declaration has been used.
   if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Func)) {
+    Constructor = cast<CXXConstructorDecl>(Constructor->getFirstDecl());
     if (Constructor->isDefaulted() && !Constructor->isDeleted()) {
       if (Constructor->isDefaultConstructor()) {
         if (Constructor->isTrivial())
           return;
-        if (!Constructor->isUsed(false))
-          DefineImplicitDefaultConstructor(Loc, Constructor);
+        DefineImplicitDefaultConstructor(Loc, Constructor);
       } else if (Constructor->isCopyConstructor()) {
-        if (!Constructor->isUsed(false))
-          DefineImplicitCopyConstructor(Loc, Constructor);
+        DefineImplicitCopyConstructor(Loc, Constructor);
       } else if (Constructor->isMoveConstructor()) {
-        if (!Constructor->isUsed(false))
-          DefineImplicitMoveConstructor(Loc, Constructor);
+        DefineImplicitMoveConstructor(Loc, Constructor);
       }
     } else if (Constructor->getInheritedConstructor()) {
-      if (!Constructor->isUsed(false))
-        DefineInheritingConstructor(Loc, Constructor);
+      DefineInheritingConstructor(Loc, Constructor);
     }
 
     MarkVTableUsed(Loc, Constructor->getParent());
   } else if (CXXDestructorDecl *Destructor =
                  dyn_cast<CXXDestructorDecl>(Func)) {
-    if (Destructor->isDefaulted() && !Destructor->isDeleted() &&
-        !Destructor->isUsed(false))
+    Destructor = cast<CXXDestructorDecl>(Destructor->getFirstDecl());
+    if (Destructor->isDefaulted() && !Destructor->isDeleted())
       DefineImplicitDestructor(Loc, Destructor);
     if (Destructor->isVirtual())
       MarkVTableUsed(Loc, Destructor->getParent());
   } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(Func)) {
-    if (MethodDecl->isDefaulted() && !MethodDecl->isDeleted() &&
-        MethodDecl->isOverloadedOperator() &&
+    if (MethodDecl->isOverloadedOperator() &&
         MethodDecl->getOverloadedOperator() == OO_Equal) {
-      if (!MethodDecl->isUsed(false)) {
+      MethodDecl = cast<CXXMethodDecl>(MethodDecl->getFirstDecl());
+      if (MethodDecl->isDefaulted() && !MethodDecl->isDeleted()) {
         if (MethodDecl->isCopyAssignmentOperator())
           DefineImplicitCopyAssignment(Loc, MethodDecl);
         else
@@ -11222,7 +11219,8 @@ void Sema::MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func) {
       }
     } else if (isa<CXXConversionDecl>(MethodDecl) &&
                MethodDecl->getParent()->isLambda()) {
-      CXXConversionDecl *Conversion = cast<CXXConversionDecl>(MethodDecl);
+      CXXConversionDecl *Conversion =
+          cast<CXXConversionDecl>(MethodDecl->getFirstDecl());
       if (Conversion->isLambdaToBlockPointerConversion())
         DefineImplicitLambdaToBlockPointerConversion(Loc, Conversion);
       else