Fix a regression from r151117: ADL requires that we attempt to complete any

associated classes, since it can find friend functions declared within them,
but overload resolution does not otherwise require argument types to be
complete.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151434 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Sema/Sema.h

@@ -1568,7 +1568,7 @@ public:
                                     Expr **Args, unsigned NumArgs,
                                     OverloadCandidateSet& CandidateSet);
   void AddArgumentDependentLookupCandidates(DeclarationName Name,
-                                            bool Operator,
+                                            bool Operator, SourceLocation Loc,
                                             Expr **Args, unsigned NumArgs,
                                 TemplateArgumentListInfo *ExplicitTemplateArgs,
                                             OverloadCandidateSet& CandidateSet,
@@ -1814,6 +1814,7 @@ public:
   CXXDestructorDecl *LookupDestructor(CXXRecordDecl *Class);
 
   void ArgumentDependentLookup(DeclarationName Name, bool Operator,
+                               SourceLocation Loc,
                                Expr **Args, unsigned NumArgs,
                                ADLResult &Functions,
                                bool StdNamespaceIsAssociated = false);

lib/Sema/SemaLookup.cpp

@@ -2558,6 +2558,7 @@ void ADLResult::insert(NamedDecl *New) {
 }
 
 void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
+                                   SourceLocation Loc,
                                    Expr **Args, unsigned NumArgs,
                                    ADLResult &Result,
                                    bool StdNamespaceIsAssociated) {
@@ -2578,6 +2579,13 @@ void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
       T2 = Args[1]->getType();
   }
 
+  // Try to complete all associated classes, in case they contain a
+  // declaration of a friend function.
+  for (AssociatedClassSet::iterator C = AssociatedClasses.begin(),
+                                    CEnd = AssociatedClasses.end();
+       C != CEnd; ++C)
+    RequireCompleteType(Loc, Context.getRecordType(*C), 0);
+
   // C++ [basic.lookup.argdep]p3:
   //   Let X be the lookup set produced by unqualified lookup (3.4.1)
   //   and let Y be the lookup set produced by argument dependent

lib/Sema/SemaOverload.cpp

@@ -740,8 +740,6 @@ namespace {
 /// Return true on unrecoverable error.
 static bool checkPlaceholderForOverload(Sema &S, Expr *&E,
                                         UnbridgedCastsSet *unbridgedCasts = 0) {
-  S.RequireCompleteType(E->getExprLoc(), E->getType(), 0);
-
   if (const BuiltinType *placeholder =  E->getType()->getAsPlaceholderType()) {
     // We can't handle overloaded expressions here because overload
     // resolution might reasonably tweak them.
@@ -7448,7 +7446,7 @@ Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
 /// candidate set (C++ [basic.lookup.argdep]).
 void
 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
-                                           bool Operator,
+                                           bool Operator, SourceLocation Loc,
                                            Expr **Args, unsigned NumArgs,
                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
                                            OverloadCandidateSet& CandidateSet,
@@ -7464,7 +7462,7 @@ Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
   // we supposed to consider on ADL candidates, anyway?
 
   // FIXME: Pass in the explicit template arguments?
-  ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns,
+  ArgumentDependentLookup(Name, Operator, Loc, Args, NumArgs, Fns,
                           StdNamespaceIsAssociated);
 
   // Erase all of the candidates we already knew about.
@@ -9223,6 +9221,7 @@ void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
 
   if (ULE->requiresADL())
     AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false,
+                                         ULE->getExprLoc(),
                                          Args, NumArgs,
                                          ExplicitTemplateArgs,
                                          CandidateSet,
@@ -9665,7 +9664,7 @@ Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn,
 
   // Add candidates from ADL.
   AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true,
-                                       Args, NumArgs,
+                                       OpLoc, Args, NumArgs,
                                        /*ExplicitTemplateArgs*/ 0,
                                        CandidateSet);
 
@@ -9886,7 +9885,7 @@ Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
 
   // Add candidates from ADL.
   AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true,
-                                       Args, 2,
+                                       OpLoc, Args, 2,
                                        /*ExplicitTemplateArgs*/ 0,
                                        CandidateSet);
 

test/SemaCXX/overload-call.cpp

@@ -536,10 +536,30 @@ namespace rdar9803316 {
 }
 
 namespace IncompleteArg {
-  // Ensure that overload resolution attempts to complete argument types.
+  // Ensure that overload resolution attempts to complete argument types when
+  // performing ADL.
   template<typename T> struct S {
     friend int f(const S&);
   };
   extern S<int> s;
   int k = f(s);
+
+  template<typename T> struct Op {
+    friend bool operator==(const Op &, const Op &);
+  };
+  extern Op<char> op;
+  bool b = op == op;
+
+  // ... and not in other cases! Nothing here requires U<int()> to be complete.
+  // (Note that instantiating U<int()> will fail.)
+  template<typename T> struct U {
+    T t;
+  };
+  struct Consumer {
+    template<typename T>
+    int operator()(const U<T> &);
+  };
+  template<typename T> U<T> &make();
+  Consumer c;
+  int n = sizeof(c(make<int()>()));
 }