Change where we handle arg-dependent diagnose_if attributes

[george.burgess.iv]

Summary

As it turns out, emitting diagnostics from places where you're not meant to emit them from is a very bad idea. :)

After some looking around, it seems that it's less insane to check for diagnose_if attributes in code that's already checking for e.g. nullness warnings. As a result, we get to rip out the diagnose_if-induced changes to overloading. Woohoo!

This also includes a slight change to how diagnose_if works: for "error" calls, we'll always assume that overload resolution chose the overload the user wanted. So, regardless of whetehr a diagnose_if attribute emits a diag or not, we'll continue building the AST/etc as usual.

This patch aims to fix PR31638, PR31639, and PR31640.

[george.burgess.iv]

Sprinkle in a few consts, use const auto * in range for loops.

[rsmith]

include/clang/Sema/Overload.h

758 ↗

(On Diff #84988)

Typo "alloates"

lib/Sema/SemaChecking.cpp

2490 ↗

(On Diff #84988)

Can this be moved inside checkCall?

[george.burgess.iv]

Addressed all feedback.

Richard noted that, because we're now doing these checks after overload resolution has occurred, we no longer need to convert arguments for arg-dependent diagnose_if checks. As a result, we get to make lots of things const. Yay!

Also, I plan to submit this (once it's LGTM'ed) to the 4.0 branch. Is that OK with you, Richard?

[george.burgess.iv]

Pinging early because this is a release blocker. :)

[aaron.ballman]

I don't see anything that looks amiss, but you should wait for @rsmith to approve.

lib/Sema/SemaChecking.cpp

2520 ↗

(On Diff #85486)

Thank you for this comment; I was about to ask about that very topic. :-D

11933 ↗

(On Diff #85486)

Unintended change?

lib/Sema/SemaOverload.cpp

6235 ↗

(On Diff #85486)

Braces might make this a bit easier to read due to the multiline if.

[george.burgess.iv]

Address feedback

[george.burgess.iv]

Thanks for the feedback!

lib/Sema/SemaChecking.cpp

2520 ↗

(On Diff #85486)

ᕕ( ᐛ )ᕗ

Makes me kinda wish there was a clean way to say "the constness of the returned value depends on the constness of this arg," though. (For values of clean that don't involve some constness_of<ArgTy, RetTy>::type kind of thing)

[rsmith]

Another "fun" testcase:

struct S {
  void operator++(int n) _diagnose_if(n, "wat", "warning");
};
void f(S s) {
  s++; // no warning
  s.operator++(1); // warning
}

include/clang/Sema/Sema.h

2638 ↗

(On Diff #86111)

Can you add a comment somewhere about here explaining why these functions are split? Something like "Argument-dependent diagnose_if attributes are checked when the function is used as a direct callee of a function call." here, and "Argument-independent diagnose_if attributes are checked on every use of the function." below.

9925 ↗

(On Diff #86111)

We have a loose convention that function parameter argument order matches source order, which would suggest that ThisArg should precede Args here.

lib/Sema/SemaExprCXX.cpp

6717 ↗

(On Diff #86111)

Can you call CheckFunctionCall instead here, and remove checkDiagnoseIfAttrsOnCall? It looks like the only reason we don't already call that is because none of its checks could ever fire for a call to a conversion function before, and that's no longer true.

lib/Sema/SemaOverload.cpp

12035 ↗

(On Diff #86111)

Likewise call CheckFunctionCall here.

12488 ↗

(On Diff #86111)

... and here.

13228 ↗

(On Diff #86111)

... and here.

test/SemaCXX/diagnose_if.cpp

614 ↗

(On Diff #86111)

constexpr is an adjective; "to a constant" might make more sense.

615 ↗

(On Diff #86111)

The range-based for is desugared to

auto &&__range = adl::Foo(1);
auto __begin = begin(__range);
auto __end = end(__range);
// ...

so the argument in the call to begin is not considered constant.

[george.burgess.iv]

Addressed all feedback

Another "fun" testcase

Ooh, shiny. Added.

test/SemaCXX/diagnose_if.cpp

615 ↗

(On Diff #86111)

Good to know. Thanks!

[george.burgess.iv]

lib/Sema/SemaChecking.cpp

11933 ↗

(On Diff #85486)

...I dunno what keeps making this change, but I'll re-undo it before I submit.

[george.burgess.iv]

Thanks for the review!

cfe/trunk/include/clang/Sema/Overload.h

struct OverloadCandidate {
     /// FailureKind - The reason why this candidate is not viable.
     /// Actually an OverloadFailureKind.
     unsigned char FailureKind;
 
     /// \brief The number of call arguments that were explicitly provided,
     /// to be used while performing partial ordering of function templates.
     unsigned ExplicitCallArguments;
 
-    /// The number of diagnose_if attributes that this overload triggered.
-    /// If any of the triggered attributes are errors, this won't count
-    /// diagnose_if warnings.
-    unsigned NumTriggeredDiagnoseIfs = 0;
-
-    /// Basically a TinyPtrVector<DiagnoseIfAttr *> that doesn't own the vector:
-    /// If NumTriggeredDiagnoseIfs is 0 or 1, this is a DiagnoseIfAttr *,
-    /// otherwise it's a pointer to an array of `NumTriggeredDiagnoseIfs`
-    /// DiagnoseIfAttr *s.
-    llvm::PointerUnion<DiagnoseIfAttr *, DiagnoseIfAttr **> DiagnoseIfInfo;
-
-    /// Gets an ArrayRef for the data at DiagnoseIfInfo. Note that this may give
-    /// you a pointer into DiagnoseIfInfo.
-    ArrayRef<DiagnoseIfAttr *> getDiagnoseIfInfo() const {
-      auto *Ptr = NumTriggeredDiagnoseIfs <= 1
-                      ? DiagnoseIfInfo.getAddrOfPtr1()
-                      : DiagnoseIfInfo.get<DiagnoseIfAttr **>();
-      return {Ptr, NumTriggeredDiagnoseIfs};
-    }
-
     union {
       DeductionFailureInfo DeductionFailure;
       
       /// FinalConversion - For a conversion function (where Function is
       /// a CXXConversionDecl), the standard conversion that occurs
       /// after the call to the overload candidate to convert the result
       /// of calling the conversion function to the required type.
       StandardConversionSequence FinalConversion;
enum CandidateSetKind {
       /// argument is of the same enum type.
       CSK_Operator
     };
 
   private:
     SmallVector<OverloadCandidate, 16> Candidates;
     llvm::SmallPtrSet<Decl *, 16> Functions;
 
-    // Allocator for ConversionSequenceLists and DiagnoseIfAttr* arrays.
-    // We store the first few of each of these inline to avoid allocation for
-    // small sets.
+    // Allocator for ConversionSequenceLists. We store the first few of these
+    // inline to avoid allocation for small sets.
     llvm::BumpPtrAllocator SlabAllocator;
 
     SourceLocation Loc;
     CandidateSetKind Kind;
 
     constexpr static unsigned NumInlineBytes =
         24 * sizeof(ImplicitConversionSequence);
     unsigned NumInlineBytesUsed;
     llvm::AlignedCharArray<alignof(void *), NumInlineBytes> InlineSpace;
 
     /// If we have space, allocates from inline storage. Otherwise, allocates
     /// from the slab allocator.
     /// FIXME: It would probably be nice to have a SmallBumpPtrAllocator
     /// instead.
+    /// FIXME: Now that this only allocates ImplicitConversionSequences, do we
+    /// want to un-generalize this?
     template <typename T>
     T *slabAllocate(unsigned N) {
       // It's simpler if this doesn't need to consider alignment.
       static_assert(alignof(T) == alignof(void *),
                     "Only works for pointer-aligned types.");
       static_assert(std::is_trivial<T>::value ||
                         std::is_same<ImplicitConversionSequence, T>::value,
                     "Add destruction logic to OverloadCandidateSet::clear().");
namespace clang {
   public:
     OverloadCandidateSet(SourceLocation Loc, CandidateSetKind CSK)
         : Loc(Loc), Kind(CSK), NumInlineBytesUsed(0) {}
     ~OverloadCandidateSet() { destroyCandidates(); }
 
     SourceLocation getLocation() const { return Loc; }
     CandidateSetKind getKind() const { return Kind; }
 
-    /// Make a DiagnoseIfAttr* array in a block of memory that will live for
-    /// as long as this OverloadCandidateSet. Returns a pointer to the start
-    /// of that array.
-    DiagnoseIfAttr **addDiagnoseIfComplaints(ArrayRef<DiagnoseIfAttr *> CA);
-
     /// \brief Determine when this overload candidate will be new to the
     /// overload set.
     bool isNewCandidate(Decl *F) {
       return Functions.insert(F->getCanonicalDecl()).second;
     }
 
     /// \brief Clear out all of the candidates.
     void clear();

cfe/trunk/include/clang/Sema/Sema.h

void AddFunctionCandidates(const UnresolvedSetImpl &Functions,
                       ArrayRef<Expr *> Args,
                       OverloadCandidateSet &CandidateSet,
                       TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr,
                       bool SuppressUserConversions = false,
                       bool PartialOverloading = false);
   void AddMethodCandidate(DeclAccessPair FoundDecl,
                           QualType ObjectType,
                           Expr::Classification ObjectClassification,
-                          Expr *ThisArg, ArrayRef<Expr *> Args,
+                          ArrayRef<Expr *> Args,
                           OverloadCandidateSet& CandidateSet,
                           bool SuppressUserConversion = false);
   void AddMethodCandidate(CXXMethodDecl *Method,
                           DeclAccessPair FoundDecl,
                           CXXRecordDecl *ActingContext, QualType ObjectType,
                           Expr::Classification ObjectClassification,
-                          Expr *ThisArg, ArrayRef<Expr *> Args,
+                          ArrayRef<Expr *> Args,
                           OverloadCandidateSet& CandidateSet,
                           bool SuppressUserConversions = false,
                           bool PartialOverloading = false,
                           ConversionSequenceList EarlyConversions = None);
   void AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
                                   DeclAccessPair FoundDecl,
                                   CXXRecordDecl *ActingContext,
                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
                                   QualType ObjectType,
                                   Expr::Classification ObjectClassification,
-                                  Expr *ThisArg,
                                   ArrayRef<Expr *> Args,
                                   OverloadCandidateSet& CandidateSet,
                                   bool SuppressUserConversions = false,
                                   bool PartialOverloading = false);
   void AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
                                     DeclAccessPair FoundDecl,
                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
                                     ArrayRef<Expr *> Args,
public:
   void NoteAllOverloadCandidates(Expr *E, QualType DestType = QualType(),
                                  bool TakingAddress = false);
 
   /// Check the enable_if expressions on the given function. Returns the first
   /// failing attribute, or NULL if they were all successful.
   EnableIfAttr *CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
                               bool MissingImplicitThis = false);
 
-  /// Check the diagnose_if attributes on the given function. Returns the
-  /// first succesful fatal attribute, or null if calling Function(Args) isn't
-  /// an error.
-  ///
-  /// This only considers ArgDependent DiagnoseIfAttrs.
-  ///
-  /// This will populate Nonfatal with all non-error DiagnoseIfAttrs that
-  /// succeed. If this function returns non-null, the contents of Nonfatal are
-  /// unspecified.
-  DiagnoseIfAttr *
-  checkArgDependentDiagnoseIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
-                              SmallVectorImpl<DiagnoseIfAttr *> &Nonfatal,
-                              bool MissingImplicitThis = false,
-                              Expr *ThisArg = nullptr);
-
-  /// Check the diagnose_if expressions on the given function. Returns the
-  /// first succesful fatal attribute, or null if using Function isn't
-  /// an error.
-  ///
-  /// This ignores all ArgDependent DiagnoseIfAttrs.
-  ///
-  /// This will populate Nonfatal with all non-error DiagnoseIfAttrs that
-  /// succeed. If this function returns non-null, the contents of Nonfatal are
-  /// unspecified.
-  DiagnoseIfAttr *
-  checkArgIndependentDiagnoseIf(FunctionDecl *Function,
-                                SmallVectorImpl<DiagnoseIfAttr *> &Nonfatal);
-
-  /// Emits the diagnostic contained in the given DiagnoseIfAttr at Loc. Also
-  /// emits a note about the location of said attribute.
-  void emitDiagnoseIfDiagnostic(SourceLocation Loc, const DiagnoseIfAttr *DIA);
+  /// Emit diagnostics for the diagnose_if attributes on Function, ignoring any
+  /// non-ArgDependent DiagnoseIfAttrs.
+  ///
+  /// Argument-dependent diagnose_if attributes should be checked each time a
+  /// function is used as a direct callee of a function call.
+  ///
+  /// Returns true if any errors were emitted.
+  bool diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
+                                           const Expr *ThisArg,
+                                           ArrayRef<const Expr *> Args,
+                                           SourceLocation Loc);
+
+  /// Emit diagnostics for the diagnose_if attributes on Function, ignoring any
+  /// ArgDependent DiagnoseIfAttrs.
+  ///
+  /// Argument-independent diagnose_if attributes should be checked on every use
+  /// of a function.
+  ///
+  /// Returns true if any errors were emitted.
+  bool diagnoseArgIndependentDiagnoseIfAttrs(const FunctionDecl *Function,
+                                             SourceLocation Loc);
 
   /// Returns whether the given function's address can be taken or not,
   /// optionally emitting a diagnostic if the address can't be taken.
   ///
   /// Returns false if taking the address of the function is illegal.
   bool checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
                                          bool Complain = false,
                                          SourceLocation Loc = SourceLocation());
bool CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
                         const FunctionProtoType *Proto);
   bool CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto);
   void CheckConstructorCall(FunctionDecl *FDecl,
                             ArrayRef<const Expr *> Args,
                             const FunctionProtoType *Proto,
                             SourceLocation Loc);
 
   void checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto,
-                 ArrayRef<const Expr *> Args, bool IsMemberFunction,
-                 SourceLocation Loc, SourceRange Range,
+                 const Expr *ThisArg, ArrayRef<const Expr *> Args,
+                 bool IsMemberFunction, SourceLocation Loc, SourceRange Range,
                  VariadicCallType CallType);
 
   bool CheckObjCString(Expr *Arg);
   ExprResult CheckOSLogFormatStringArg(Expr *Arg);
 
   ExprResult CheckBuiltinFunctionCall(FunctionDecl *FDecl,
                                       unsigned BuiltinID, CallExpr *TheCall);
 

cfe/trunk/lib/Sema/SemaChecking.cpp

static void CheckNonNullArguments(Sema &S,
   for (unsigned ArgIndex = 0, ArgIndexEnd = NonNullArgs.size(); 
        ArgIndex != ArgIndexEnd; ++ArgIndex) {
     if (NonNullArgs[ArgIndex])
       CheckNonNullArgument(S, Args[ArgIndex], CallSiteLoc);
   }
 }
 
 /// Handles the checks for format strings, non-POD arguments to vararg
-/// functions, and NULL arguments passed to non-NULL parameters.
+/// functions, NULL arguments passed to non-NULL parameters, and diagnose_if
+/// attributes.
 void Sema::checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto,
-                     ArrayRef<const Expr *> Args, bool IsMemberFunction,
-                     SourceLocation Loc, SourceRange Range,
-                     VariadicCallType CallType) {
+                     const Expr *ThisArg, ArrayRef<const Expr *> Args,
+                     bool IsMemberFunction, SourceLocation Loc,
+                     SourceRange Range, VariadicCallType CallType) {
   // FIXME: We should check as much as we can in the template definition.
   if (CurContext->isDependentContext())
     return;
 
   // Printf and scanf checking.
   llvm::SmallBitVector CheckedVarArgs;
   if (FDecl) {
     for (const auto *I : FDecl->specific_attrs<FormatAttr>()) {
if (FDecl || Proto) {
     CheckNonNullArguments(*this, FDecl, Proto, Args, Loc);
 
     // Type safety checking.
     if (FDecl) {
       for (const auto *I : FDecl->specific_attrs<ArgumentWithTypeTagAttr>())
         CheckArgumentWithTypeTag(I, Args.data());
     }
   }
+
+  if (FD)
+    diagnoseArgDependentDiagnoseIfAttrs(FD, ThisArg, Args, Loc);
 }
 
 /// CheckConstructorCall - Check a constructor call for correctness and safety
 /// properties not enforced by the C type system.
 void Sema::CheckConstructorCall(FunctionDecl *FDecl,
                                 ArrayRef<const Expr *> Args,
                                 const FunctionProtoType *Proto,
                                 SourceLocation Loc) {
   VariadicCallType CallType =
     Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
-  checkCall(FDecl, Proto, Args, /*IsMemberFunction=*/true, Loc, SourceRange(), 
-            CallType);
+  checkCall(FDecl, Proto, /*ThisArg=*/nullptr, Args, /*IsMemberFunction=*/true,
+            Loc, SourceRange(), CallType);
 }
 
 /// CheckFunctionCall - Check a direct function call for various correctness
 /// and safety properties not strictly enforced by the C type system.
 bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
                              const FunctionProtoType *Proto) {
   bool IsMemberOperatorCall = isa<CXXOperatorCallExpr>(TheCall) &&
                               isa<CXXMethodDecl>(FDecl);
   bool IsMemberFunction = isa<CXXMemberCallExpr>(TheCall) ||
                           IsMemberOperatorCall;
   VariadicCallType CallType = getVariadicCallType(FDecl, Proto,
                                                   TheCall->getCallee());
   Expr** Args = TheCall->getArgs();
   unsigned NumArgs = TheCall->getNumArgs();
+
+  Expr *ImplicitThis = nullptr;
   if (IsMemberOperatorCall) {
     // If this is a call to a member operator, hide the first argument
     // from checkCall.
     // FIXME: Our choice of AST representation here is less than ideal.
+    ImplicitThis = Args[0];
     ++Args;
     --NumArgs;
-  }
-  checkCall(FDecl, Proto, llvm::makeArrayRef(Args, NumArgs), 
+  } else if (IsMemberFunction)
+    ImplicitThis =
+        cast<CXXMemberCallExpr>(TheCall)->getImplicitObjectArgument();
+
+  checkCall(FDecl, Proto, ImplicitThis, llvm::makeArrayRef(Args, NumArgs),
             IsMemberFunction, TheCall->getRParenLoc(),
             TheCall->getCallee()->getSourceRange(), CallType);
 
   IdentifierInfo *FnInfo = FDecl->getIdentifier();
   // None of the checks below are needed for functions that don't have
   // simple names (e.g., C++ conversion functions).
   if (!FnInfo)
     return false;
bool Sema::CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
   return false;
 }
 
 bool Sema::CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation lbrac, 
                                ArrayRef<const Expr *> Args) {
   VariadicCallType CallType =
       Method->isVariadic() ? VariadicMethod : VariadicDoesNotApply;
 
-  checkCall(Method, nullptr, Args,
-            /*IsMemberFunction=*/false, lbrac, Method->getSourceRange(), 
+  checkCall(Method, nullptr, /*ThisArg=*/nullptr, Args,
+            /*IsMemberFunction=*/false, lbrac, Method->getSourceRange(),
             CallType);
 
   return false;
 }
 
 bool Sema::CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
                             const FunctionProtoType *Proto) {
   QualType Ty;
bool Sema::CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
   if (!Proto || !Proto->isVariadic()) {
     CallType = VariadicDoesNotApply;
   } else if (Ty->isBlockPointerType()) {
     CallType = VariadicBlock;
   } else { // Ty->isFunctionPointerType()
     CallType = VariadicFunction;
   }
 
-  checkCall(NDecl, Proto,
+  checkCall(NDecl, Proto, /*ThisArg=*/nullptr,
             llvm::makeArrayRef(TheCall->getArgs(), TheCall->getNumArgs()),
             /*IsMemberFunction=*/false, TheCall->getRParenLoc(),
             TheCall->getCallee()->getSourceRange(), CallType);
 
   return false;
 }
 
 /// Checks function calls when a FunctionDecl or a NamedDecl is not available,
 /// such as function pointers returned from functions.
 bool Sema::CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto) {
   VariadicCallType CallType = getVariadicCallType(/*FDecl=*/nullptr, Proto,
                                                   TheCall->getCallee());
-  checkCall(/*FDecl=*/nullptr, Proto,
+  checkCall(/*FDecl=*/nullptr, Proto, /*ThisArg=*/nullptr,
             llvm::makeArrayRef(TheCall->getArgs(), TheCall->getNumArgs()),
             /*IsMemberFunction=*/false, TheCall->getRParenLoc(),
             TheCall->getCallee()->getSourceRange(), CallType);
 
   return false;
 }
 
 static bool isValidOrderingForOp(int64_t Ordering, AtomicExpr::AtomicOp Op) {

cfe/trunk/lib/Sema/SemaExpr.cpp

if (isa<BindingDecl>(D)) {
 
       Diag(Loc, diag::err_auto_variable_cannot_appear_in_own_initializer)
         << D->getDeclName() << (unsigned)AT->getKeyword();
     }
     return true;
   }
 
   // See if this is a deleted function.
-  SmallVector<DiagnoseIfAttr *, 4> DiagnoseIfWarnings;
   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
     if (FD->isDeleted()) {
       auto *Ctor = dyn_cast<CXXConstructorDecl>(FD);
       if (Ctor && Ctor->isInheritingConstructor())
         Diag(Loc, diag::err_deleted_inherited_ctor_use)
             << Ctor->getParent()
             << Ctor->getInheritedConstructor().getConstructor()->getParent();
       else 
         Diag(Loc, diag::err_deleted_function_use);
       NoteDeletedFunction(FD);
       return true;
     }
 
     // If the function has a deduced return type, and we can't deduce it,
     // then we can't use it either.
     if (getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() &&
         DeduceReturnType(FD, Loc))
       return true;
 
     if (getLangOpts().CUDA && !CheckCUDACall(Loc, FD))
       return true;
 
-    if (const DiagnoseIfAttr *A =
-            checkArgIndependentDiagnoseIf(FD, DiagnoseIfWarnings)) {
-      emitDiagnoseIfDiagnostic(Loc, A);
+    if (diagnoseArgIndependentDiagnoseIfAttrs(FD, Loc))
       return true;
-    }
-  }
 
   // [OpenMP 4.0], 2.15 declare reduction Directive, Restrictions
   // Only the variables omp_in and omp_out are allowed in the combiner.
   // Only the variables omp_priv and omp_orig are allowed in the
   // initializer-clause.
   auto *DRD = dyn_cast<OMPDeclareReductionDecl>(CurContext);
   if (LangOpts.OpenMP && DRD && !CurContext->containsDecl(D) &&
       isa<VarDecl>(D)) {
     Diag(Loc, diag::err_omp_wrong_var_in_declare_reduction)
         << getCurFunction()->HasOMPDeclareReductionCombiner;
     Diag(D->getLocation(), diag::note_entity_declared_at) << D;
     return true;
   }
 
-  for (const auto *W : DiagnoseIfWarnings)
-    emitDiagnoseIfDiagnostic(Loc, W);
-
   DiagnoseAvailabilityOfDecl(*this, D, Loc, UnknownObjCClass,
                              ObjCPropertyAccess);
 
   DiagnoseUnusedOfDecl(*this, D, Loc);
 
   diagnoseUseOfInternalDeclInInlineFunction(*this, D, Loc);
 
   return false;
S.Diag(Fn->getLocStart(),
                ? diag::err_ovl_no_viable_member_function_in_call
                : diag::err_ovl_no_viable_function_in_call)
         << Callee << Callee->getSourceRange();
     S.Diag(Callee->getLocation(),
            diag::note_ovl_candidate_disabled_by_function_cond_attr)
         << Attr->getCond()->getSourceRange() << Attr->getMessage();
     return;
   }
-
-  SmallVector<DiagnoseIfAttr *, 4> Nonfatal;
-  if (const DiagnoseIfAttr *Attr = S.checkArgDependentDiagnoseIf(
-          Callee, ArgExprs, Nonfatal, /*MissingImplicitThis=*/true)) {
-    S.emitDiagnoseIfDiagnostic(Fn->getLocStart(), Attr);
-    return;
-  }
-
-  for (const auto *W : Nonfatal)
-    S.emitDiagnoseIfDiagnostic(Fn->getLocStart(), W);
 }
 
 /// ActOnCallExpr - Handle a call to Fn with the specified array of arguments.
 /// This provides the location of the left/right parens and a list of comma
 /// locations.
 ExprResult Sema::ActOnCallExpr(Scope *Scope, Expr *Fn, SourceLocation LParenLoc,
                                MultiExprArg ArgExprs, SourceLocation RParenLoc,
                                Expr *ExecConfig, bool IsExecConfig) {

cfe/trunk/lib/Sema/SemaExprCXX.cpp

ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
 
   QualType ResultType = Method->getReturnType();
   ExprValueKind VK = Expr::getValueKindForType(ResultType);
   ResultType = ResultType.getNonLValueExprType(Context);
 
   CXXMemberCallExpr *CE =
     new (Context) CXXMemberCallExpr(Context, ME, None, ResultType, VK,
                                     Exp.get()->getLocEnd());
+
+  if (CheckFunctionCall(Method, CE,
+                        Method->getType()->castAs<FunctionProtoType>()))
+    return ExprError();
+
   return CE;
 }
 
 ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
                                       SourceLocation RParen) {
   // If the operand is an unresolved lookup expression, the expression is ill-
   // formed per [over.over]p1, because overloaded function names cannot be used
   // without arguments except in explicit contexts.

cfe/trunk/lib/Sema/SemaLookup.cpp

for (NamedDecl *CandDecl : Candidates) {
     if (CandDecl->isInvalidDecl())
       continue;
 
     DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
     auto CtorInfo = getConstructorInfo(Cand);
     if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
       if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
         AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
-                           /*ThisArg=*/nullptr,
                            llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
       else if (CtorInfo)
         AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
                              llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
       else
         AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
                              true);
     } else if (FunctionTemplateDecl *Tmpl =
                  dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
       if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
         AddMethodTemplateCandidate(
             Tmpl, Cand, RD, nullptr, ThisTy, Classification,
-            /*ThisArg=*/nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
+            llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
       else if (CtorInfo)
         AddTemplateOverloadCandidate(
             CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
             llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
       else
         AddTemplateOverloadCandidate(
             Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
     } else {

cfe/trunk/lib/Sema/SemaOverload.cpp

for (auto &C : i->Conversions)
       C.~ImplicitConversionSequence();
     if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
       i->DeductionFailure.Destroy();
   }
 }
 
 void OverloadCandidateSet::clear() {
   destroyCandidates();
-  // DiagnoseIfAttrs are just pointers, so we don't need to destroy them.
   SlabAllocator.Reset();
   NumInlineBytesUsed = 0;
   Candidates.clear();
   Functions.clear();
 }
 
-DiagnoseIfAttr **
-OverloadCandidateSet::addDiagnoseIfComplaints(ArrayRef<DiagnoseIfAttr *> CA) {
-  auto *DIA = slabAllocate<DiagnoseIfAttr *>(CA.size());
-  std::uninitialized_copy(CA.begin(), CA.end(), DIA);
-  return DIA;
-}
-
 namespace {
   class UnbridgedCastsSet {
     struct Entry {
       Expr **Addr;
       Expr *Saved;
     };
     SmallVector<Entry, 2> Entries;
     
if (!T2.isNull() && T2->isEnumeralType()) {
     QualType ArgType = Proto->getParamType(1).getNonReferenceType();
     if (Context.hasSameUnqualifiedType(T2, ArgType))
       return true;
   }
 
   return false;
 }
 
-static void initDiagnoseIfComplaint(Sema &S, OverloadCandidateSet &CandidateSet,
-                                    OverloadCandidate &Candidate,
-                                    FunctionDecl *Function,
-                                    ArrayRef<Expr *> Args,
-                                    bool MissingImplicitThis = false,
-                                    Expr *ExplicitThis = nullptr) {
-  SmallVector<DiagnoseIfAttr *, 8> Results;
-  if (DiagnoseIfAttr *DIA = S.checkArgDependentDiagnoseIf(
-          Function, Args, Results, MissingImplicitThis, ExplicitThis)) {
-    Results.clear();
-    Results.push_back(DIA);
-  }
-
-  Candidate.NumTriggeredDiagnoseIfs = Results.size();
-  if (Results.empty())
-    Candidate.DiagnoseIfInfo = nullptr;
-  else if (Results.size() == 1)
-    Candidate.DiagnoseIfInfo = Results[0];
-  else
-    Candidate.DiagnoseIfInfo = CandidateSet.addDiagnoseIfComplaints(Results);
-}
-
 /// AddOverloadCandidate - Adds the given function to the set of
 /// candidate functions, using the given function call arguments.  If
 /// @p SuppressUserConversions, then don't allow user-defined
 /// conversions via constructors or conversion operators.
 ///
 /// \param PartialOverloading true if we are performing "partial" overloading
 /// based on an incomplete set of function arguments. This feature is used by
 /// code completion.
if (!isa<CXXConstructorDecl>(Method)) {
       // If we get here, it's because we're calling a member function
       // that is named without a member access expression (e.g.,
       // "this->f") that was either written explicitly or created
       // implicitly. This can happen with a qualified call to a member
       // function, e.g., X::f(). We use an empty type for the implied
       // object argument (C++ [over.call.func]p3), and the acting context
       // is irrelevant.
       AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(),
-                         Expr::Classification::makeSimpleLValue(),
-                         /*ThisArg=*/nullptr, Args, CandidateSet,
-                         SuppressUserConversions, PartialOverloading,
-                         EarlyConversions);
+                         Expr::Classification::makeSimpleLValue(), Args,
+                         CandidateSet, SuppressUserConversions,
+                         PartialOverloading, EarlyConversions);
       return;
     }
     // We treat a constructor like a non-member function, since its object
     // argument doesn't participate in overload resolution.
   }
 
   if (!CandidateSet.isNewCandidate(Function))
     return;
if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
     return;
   }
 
   if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
     Candidate.Viable = false;
     Candidate.FailureKind = ovl_fail_ext_disabled;
     return;
   }
-
-  initDiagnoseIfComplaint(*this, CandidateSet, Candidate, Function, Args);
 }
 
 ObjCMethodDecl *
 Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
                        SmallVectorImpl<ObjCMethodDecl *> &Methods) {
   if (Methods.size() <= 1)
     return nullptr;
 
if (!EIA->getCond()->EvaluateWithSubstitution(
       return EIA;
 
     if (!Result.isInt() || !Result.getInt().getBoolValue())
       return EIA;
   }
   return nullptr;
 }
 
-static bool gatherDiagnoseIfAttrs(FunctionDecl *Function, bool ArgDependent,
-                                  SmallVectorImpl<DiagnoseIfAttr *> &Errors,
-                                  SmallVectorImpl<DiagnoseIfAttr *> &Nonfatal) {
-  for (auto *DIA : Function->specific_attrs<DiagnoseIfAttr>())
-    if (ArgDependent == DIA->getArgDependent()) {
-      if (DIA->isError())
-        Errors.push_back(DIA);
-      else
-        Nonfatal.push_back(DIA);
-    }
+template <typename CheckFn>
+static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const FunctionDecl *FD,
+                                        bool ArgDependent, SourceLocation Loc,
+                                        CheckFn &&IsSuccessful) {
+  SmallVector<const DiagnoseIfAttr *, 8> Attrs;
+  for (const auto *DIA : FD->specific_attrs<DiagnoseIfAttr>()) {
+    if (ArgDependent == DIA->getArgDependent())
+      Attrs.push_back(DIA);
 
-  return !Errors.empty() || !Nonfatal.empty();
-}
+  // Common case: No diagnose_if attributes, so we can quit early.
+  if (Attrs.empty())
+    return false;
+
+  auto WarningBegin = std::stable_partition(
+      Attrs.begin(), Attrs.end(),
+      [](const DiagnoseIfAttr *DIA) { return DIA->isError(); });
 
-template <typename CheckFn>
-static DiagnoseIfAttr *
-checkDiagnoseIfAttrsWith(const SmallVectorImpl<DiagnoseIfAttr *> &Errors,
-                         SmallVectorImpl<DiagnoseIfAttr *> &Nonfatal,
-                         CheckFn &&IsSuccessful) {
   // Note that diagnose_if attributes are late-parsed, so they appear in the
   // correct order (unlike enable_if attributes).
-  auto ErrAttr = llvm::find_if(Errors, IsSuccessful);
-  if (ErrAttr != Errors.end())
-    return *ErrAttr;
-
-  llvm::erase_if(Nonfatal, [&](DiagnoseIfAttr *A) { return !IsSuccessful(A); });
-  return nullptr;
+  auto ErrAttr = llvm::find_if(llvm::make_range(Attrs.begin(), WarningBegin),
+                               IsSuccessful);
+  if (ErrAttr != WarningBegin) {
+    const DiagnoseIfAttr *DIA = *ErrAttr;
+    S.Diag(Loc, diag::err_diagnose_if_succeeded) << DIA->getMessage();
+    S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
+        << DIA->getParent() << DIA->getCond()->getSourceRange();
+    return true;
   }
 
-DiagnoseIfAttr *
-Sema::checkArgDependentDiagnoseIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
-                                  SmallVectorImpl<DiagnoseIfAttr *> &Nonfatal,
-                                  bool MissingImplicitThis,
-                                  Expr *ThisArg) {
-  SmallVector<DiagnoseIfAttr *, 4> Errors;
-  if (!gatherDiagnoseIfAttrs(Function, /*ArgDependent=*/true, Errors, Nonfatal))
-    return nullptr;
+  for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))
+    if (IsSuccessful(DIA)) {
+      S.Diag(Loc, diag::warn_diagnose_if_succeeded) << DIA->getMessage();
+      S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
+          << DIA->getParent() << DIA->getCond()->getSourceRange();
+    }
 
-  SFINAETrap Trap(*this);
-  SmallVector<Expr *, 16> ConvertedArgs;
-  Expr *ConvertedThis;
-  if (!convertArgsForAvailabilityChecks(*this, Function, ThisArg, Args, Trap,
-                                        MissingImplicitThis, ConvertedThis,
-                                        ConvertedArgs))
-    return nullptr;
+  return false;
+}
 
-  return checkDiagnoseIfAttrsWith(Errors, Nonfatal, [&](DiagnoseIfAttr *DIA) {
+bool Sema::diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
+                                               const Expr *ThisArg,
+                                               ArrayRef<const Expr *> Args,
+                                               SourceLocation Loc) {
+  return diagnoseDiagnoseIfAttrsWith(
+      *this, Function, /*ArgDependent=*/true, Loc,
+      [&](const DiagnoseIfAttr *DIA) {
         APValue Result;
-    // It's sane to use the same ConvertedArgs for any redecl of this function,
-    // since EvaluateWithSubstitution only cares about the position of each
+        // It's sane to use the same Args for any redecl of this function, since
+        // EvaluateWithSubstitution only cares about the position of each
         // argument in the arg list, not the ParmVarDecl* it maps to.
         if (!DIA->getCond()->EvaluateWithSubstitution(
-            Result, Context, DIA->getParent(), ConvertedArgs, ConvertedThis))
+                Result, Context, DIA->getParent(), Args, ThisArg))
           return false;
         return Result.isInt() && Result.getInt().getBoolValue();
       });
 }
 
-DiagnoseIfAttr *Sema::checkArgIndependentDiagnoseIf(
-    FunctionDecl *Function, SmallVectorImpl<DiagnoseIfAttr *> &Nonfatal) {
-  SmallVector<DiagnoseIfAttr *, 4> Errors;
-  if (!gatherDiagnoseIfAttrs(Function, /*ArgDependent=*/false, Errors,
-                             Nonfatal))
-    return nullptr;
-
-  return checkDiagnoseIfAttrsWith(Errors, Nonfatal, [&](DiagnoseIfAttr *DIA) {
+bool Sema::diagnoseArgIndependentDiagnoseIfAttrs(const FunctionDecl *Function,
+                                                 SourceLocation Loc) {
+  return diagnoseDiagnoseIfAttrsWith(
+      *this, Function, /*ArgDependent=*/false, Loc,
+      [&](const DiagnoseIfAttr *DIA) {
         bool Result;
         return DIA->getCond()->EvaluateAsBooleanCondition(Result, Context) &&
                Result;
       });
 }
 
-void Sema::emitDiagnoseIfDiagnostic(SourceLocation Loc,
-                                    const DiagnoseIfAttr *DIA) {
-  auto Code = DIA->isError() ? diag::err_diagnose_if_succeeded
-                             : diag::warn_diagnose_if_succeeded;
-  Diag(Loc, Code) << DIA->getMessage();
-  Diag(DIA->getLocation(), diag::note_from_diagnose_if)
-      << DIA->getParent() << DIA->getCond()->getSourceRange();
-}
-
 /// \brief Add all of the function declarations in the given function set to
 /// the overload candidate set.
 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
                                  ArrayRef<Expr *> Args,
                                  OverloadCandidateSet& CandidateSet,
                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
                                  bool SuppressUserConversions,
                                  bool PartialOverloading) {
   for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
     NamedDecl *D = F.getDecl()->getUnderlyingDecl();
     if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
       if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
         AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
                            cast<CXXMethodDecl>(FD)->getParent(),
                            Args[0]->getType(), Args[0]->Classify(Context),
-                           Args[0], Args.slice(1), CandidateSet,
-                           SuppressUserConversions, PartialOverloading);
+                           Args.slice(1), CandidateSet, SuppressUserConversions,
+                           PartialOverloading);
       else
         AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet,
                              SuppressUserConversions, PartialOverloading);
     } else {
       FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
       if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
           !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic())
         AddMethodTemplateCandidate(
             FunTmpl, F.getPair(),
             cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
             ExplicitTemplateArgs, Args[0]->getType(),
-            Args[0]->Classify(Context), Args[0], Args.slice(1), CandidateSet,
+            Args[0]->Classify(Context), Args.slice(1), CandidateSet,
             SuppressUserConversions, PartialOverloading);
       else
         AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
                                      ExplicitTemplateArgs, Args,
                                      CandidateSet, SuppressUserConversions,
                                      PartialOverloading);
     }
   }
 }
 
 /// AddMethodCandidate - Adds a named decl (which is some kind of
 /// method) as a method candidate to the given overload set.
 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
                               QualType ObjectType,
                               Expr::Classification ObjectClassification,
-                              Expr *ThisArg,
                               ArrayRef<Expr *> Args,
                               OverloadCandidateSet& CandidateSet,
                               bool SuppressUserConversions) {
   NamedDecl *Decl = FoundDecl.getDecl();
   CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
 
   if (isa<UsingShadowDecl>(Decl))
     Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
 
   if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
     assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
            "Expected a member function template");
     AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
-                               /*ExplicitArgs*/ nullptr,
-                               ObjectType, ObjectClassification,
-                               ThisArg, Args, CandidateSet,
+                               /*ExplicitArgs*/ nullptr, ObjectType,
+                               ObjectClassification, Args, CandidateSet,
                                SuppressUserConversions);
   } else {
     AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
-                       ObjectType, ObjectClassification,
-                       ThisArg, Args,
-                       CandidateSet, SuppressUserConversions);
+                       ObjectType, ObjectClassification, Args, CandidateSet,
+                       SuppressUserConversions);
   }
 }
 
 /// AddMethodCandidate - Adds the given C++ member function to the set
 /// of candidate functions, using the given function call arguments
 /// and the object argument (@c Object). For example, in a call
 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
 /// allow user-defined conversions via constructors or conversion
 /// operators.
 void
 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
                          CXXRecordDecl *ActingContext, QualType ObjectType,
                          Expr::Classification ObjectClassification,
-                         Expr *ThisArg, ArrayRef<Expr *> Args,
+                         ArrayRef<Expr *> Args,
                          OverloadCandidateSet &CandidateSet,
                          bool SuppressUserConversions,
                          bool PartialOverloading,
                          ConversionSequenceList EarlyConversions) {
   const FunctionProtoType *Proto
     = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
   assert(Proto && "Methods without a prototype cannot be overloaded");
   assert(!isa<CXXConstructorDecl>(Method) &&
Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
   }
 
   if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
     Candidate.Viable = false;
     Candidate.FailureKind = ovl_fail_enable_if;
     Candidate.DeductionFailure.Data = FailedAttr;
     return;
   }
-
-  initDiagnoseIfComplaint(*this, CandidateSet, Candidate, Method, Args,
-                          /*MissingImplicitThis=*/!ThisArg, ThisArg);
 }
 
 /// \brief Add a C++ member function template as a candidate to the candidate
 /// set, using template argument deduction to produce an appropriate member
 /// function template specialization.
 void
 Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
                                  DeclAccessPair FoundDecl,
                                  CXXRecordDecl *ActingContext,
                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
                                  QualType ObjectType,
                                  Expr::Classification ObjectClassification,
-                                 Expr *ThisArg,
                                  ArrayRef<Expr *> Args,
                                  OverloadCandidateSet& CandidateSet,
                                  bool SuppressUserConversions,
                                  bool PartialOverloading) {
   if (!CandidateSet.isNewCandidate(MethodTmpl))
     return;
 
   // C++ [over.match.funcs]p7:
Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
   }
 
   // Add the function template specialization produced by template argument
   // deduction as a candidate.
   assert(Specialization && "Missing member function template specialization?");
   assert(isa<CXXMethodDecl>(Specialization) &&
          "Specialization is not a member function?");
   AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
-                     ActingContext, ObjectType, ObjectClassification,
-                     /*ThisArg=*/ThisArg, Args, CandidateSet,
-                     SuppressUserConversions, PartialOverloading, Conversions);
+                     ActingContext, ObjectType, ObjectClassification, Args,
+                     CandidateSet, SuppressUserConversions, PartialOverloading,
+                     Conversions);
 }
 
 /// \brief Add a C++ function template specialization as a candidate
 /// in the candidate set, using template argument deduction to produce
 /// an appropriate function template specialization.
 void
 Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
                                    DeclAccessPair FoundDecl,
Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
   }
 
   if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
     Candidate.Viable = false;
     Candidate.FailureKind = ovl_fail_enable_if;
     Candidate.DeductionFailure.Data = FailedAttr;
     return;
   }
-
-  initDiagnoseIfComplaint(*this, CandidateSet, Candidate, Conversion, None, false, From);
 }
 
 /// \brief Adds a conversion function template specialization
 /// candidate to the overload set, using template argument deduction
 /// to deduce the template arguments of the conversion function
 /// template from the type that we are converting to (C++
 /// [temp.deduct.conv]).
 void
void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
   }
 
   if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
     Candidate.Viable = false;
     Candidate.FailureKind = ovl_fail_enable_if;
     Candidate.DeductionFailure.Data = FailedAttr;
     return;
   }
-
-  initDiagnoseIfComplaint(*this, CandidateSet, Candidate, Conversion, None);
 }
 
 /// \brief Add overload candidates for overloaded operators that are
 /// member functions.
 ///
 /// Add the overloaded operator candidates that are member functions
 /// for the operator Op that was used in an operator expression such
 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
     LookupQualifiedName(Operators, T1Rec->getDecl());
     Operators.suppressDiagnostics();
 
     for (LookupResult::iterator Oper = Operators.begin(),
                              OperEnd = Operators.end();
          Oper != OperEnd;
          ++Oper)
       AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
-                         Args[0]->Classify(Context), Args[0], Args.slice(1),
+                         Args[0]->Classify(Context), Args.slice(1),
                          CandidateSet, /*SuppressUserConversions=*/false);
   }
 }
 
 /// AddBuiltinCandidate - Add a candidate for a built-in
 /// operator. ResultTy and ParamTys are the result and parameter types
 /// of the built-in candidate, respectively. Args and NumArgs are the
 /// arguments being passed to the candidate. IsAssignmentOperator
void Sema::diagnoseEquivalentInternalLinkageDeclarations(
 
   for (auto *E : Equiv) {
     Module *M = getOwningModule(const_cast<NamedDecl*>(E));
     Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
         << !M << (M ? M->getFullModuleName() : "");
   }
 }
 
-static bool isCandidateUnavailableDueToDiagnoseIf(const OverloadCandidate &OC) {
-  ArrayRef<DiagnoseIfAttr *> Info = OC.getDiagnoseIfInfo();
-  if (!Info.empty() && Info[0]->isError())
-    return true;
-
-  assert(llvm::all_of(Info,
-                      [](const DiagnoseIfAttr *A) { return !A->isError(); }) &&
-         "DiagnoseIf info shouldn't have mixed warnings and errors.");
-  return false;
-}
-
 /// \brief Computes the best viable function (C++ 13.3.3)
 /// within an overload candidate set.
 ///
 /// \param Loc The location of the function name (or operator symbol) for
 /// which overload resolution occurs.
 ///
 /// \param Best If overload resolution was successful or found a deleted
 /// function, \p Best points to the candidate function found.
if (Cand->Viable &&
       Best = end();
       return OR_Ambiguous;
     }
   }
 
   // Best is the best viable function.
   if (Best->Function &&
       (Best->Function->isDeleted() ||
-       S.isFunctionConsideredUnavailable(Best->Function) ||
-       isCandidateUnavailableDueToDiagnoseIf(*Best)))
+       S.isFunctionConsideredUnavailable(Best->Function)))
     return OR_Deleted;
 
   if (!EquivalentCands.empty())
     S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
                                                     EquivalentCands);
 
-  for (const auto *W : Best->getDiagnoseIfInfo()) {
-    assert(W->isWarning() && "Errors should've been caught earlier!");
-    S.emitDiagnoseIfDiagnostic(Loc, W);
-  }
-
   return OR_Success;
 }
 
 namespace {
 
 enum OverloadCandidateKind {
   oc_function,
   oc_method,
if (Fn->isDeleted() || S.isFunctionConsideredUnavailable(Fn)) {
         ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
 
       S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
         << FnKind << FnDesc
         << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
       MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
       return;
     }
-    if (isCandidateUnavailableDueToDiagnoseIf(*Cand)) {
-      auto *A = Cand->DiagnoseIfInfo.get<DiagnoseIfAttr *>();
-      assert(A->isError() && "Non-error diagnose_if disables a candidate?");
-      S.Diag(Cand->Function->getLocation(),
-             diag::note_ovl_candidate_disabled_by_function_cond_attr)
-          << A->getCond()->getSourceRange() << A->getMessage();
-      return;
-    }
 
     // We don't really have anything else to say about viable candidates.
     S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
     return;
   }
 
   switch (Cand->FailureKind) {
   case ovl_fail_too_many_arguments:
if (FnDecl) {
       Args[0] = Input;
       CallExpr *TheCall =
         new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(), ArgsArray,
                                           ResultTy, VK, OpLoc, false);
 
       if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
         return ExprError();
 
+      if (CheckFunctionCall(FnDecl, TheCall,
+                            FnDecl->getType()->castAs<FunctionProtoType>()))
+        return ExprError();
+
       return MaybeBindToTemporary(TheCall);
     } else {
       // We matched a built-in operator. Convert the arguments, then
       // break out so that we will build the appropriate built-in
       // operator node.
       ExprResult InputRes =
         PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
                                   Best->Conversions[0], AA_Passing);
case OR_Success: {
                                             Args, ResultTy, VK, OpLoc,
                                             FPFeatures.fp_contract);
 
         if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
                                 FnDecl))
           return ExprError();
 
         ArrayRef<const Expr *> ArgsArray(Args, 2);
+        const Expr *ImplicitThis = nullptr;
         // Cut off the implicit 'this'.
-        if (isa<CXXMethodDecl>(FnDecl))
+        if (isa<CXXMethodDecl>(FnDecl)) {
+          ImplicitThis = ArgsArray[0];
           ArgsArray = ArgsArray.slice(1);
+        }
 
         // Check for a self move.
         if (Op == OO_Equal)
           DiagnoseSelfMove(Args[0], Args[1], OpLoc);
 
-        checkCall(FnDecl, nullptr, ArgsArray, isa<CXXMethodDecl>(FnDecl), OpLoc, 
-                  TheCall->getSourceRange(), VariadicDoesNotApply);
+        checkCall(FnDecl, nullptr, ImplicitThis, ArgsArray,
+                  isa<CXXMethodDecl>(FnDecl), OpLoc, TheCall->getSourceRange(),
+                  VariadicDoesNotApply);
 
         return MaybeBindToTemporary(TheCall);
       } else {
         // We matched a built-in operator. Convert the arguments, then
         // break out so that we will build the appropriate built-in
         // operator node.
         ExprResult ArgsRes0 =
           PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
case OR_Success: {
           new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
                                             FnExpr.get(), Args,
                                             ResultTy, VK, RLoc,
                                             false);
 
         if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
           return ExprError();
 
+        if (CheckFunctionCall(Method, TheCall,
+                              Method->getType()->castAs<FunctionProtoType>()))
+          return ExprError();
+
         return MaybeBindToTemporary(TheCall);
       } else {
         // We matched a built-in operator. Convert the arguments, then
         // break out so that we will build the appropriate built-in
         // operator node.
         ExprResult ArgsRes0 =
           PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
                                     Best->Conversions[0], AA_Passing);
if (isa<MemberExpr>(NakedMemExpr)) {
 
     // FIXME: avoid copy.
     TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
     if (UnresExpr->hasExplicitTemplateArgs()) {
       UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
       TemplateArgs = &TemplateArgsBuffer;
     }
 
-    // Poor-programmer's Lazy<Expr *>; isImplicitAccess requires stripping
-    // parens/casts, which would be nice to avoid potentially doing multiple
-    // times.
-    llvm::Optional<Expr *> UnresolvedBase;
-    auto GetUnresolvedBase = [&] {
-      if (!UnresolvedBase.hasValue())
-        UnresolvedBase =
-          UnresExpr->isImplicitAccess() ? nullptr : UnresExpr->getBase();
-      return *UnresolvedBase;
-    };
     for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
            E = UnresExpr->decls_end(); I != E; ++I) {
 
       NamedDecl *Func = *I;
       CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
       if (isa<UsingShadowDecl>(Func))
         Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
 
 
       // Microsoft supports direct constructor calls.
       if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
         AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(),
                              Args, CandidateSet);
       } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
         // If explicit template arguments were provided, we can't call a
         // non-template member function.
         if (TemplateArgs)
           continue;
 
         AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
-                           ObjectClassification,
-                           /*ThisArg=*/GetUnresolvedBase(), Args, CandidateSet,
+                           ObjectClassification, Args, CandidateSet,
                            /*SuppressUserConversions=*/false);
       } else {
         AddMethodTemplateCandidate(
             cast<FunctionTemplateDecl>(Func), I.getPair(), ActingDC,
-            TemplateArgs, ObjectType, ObjectClassification,
-            /*ThisArg=*/GetUnresolvedBase(), Args, CandidateSet,
+            TemplateArgs, ObjectType, ObjectClassification, Args, CandidateSet,
             /*SuppressUsedConversions=*/false);
       }
     }
 
     DeclarationName DeclName = UnresExpr->getMemberName();
 
     UnbridgedCasts.restore();
 
if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
       Diag(MemE->getMemberLoc(),
            diag::err_ovl_no_viable_member_function_in_call)
           << Method << Method->getSourceRange();
       Diag(Method->getLocation(),
            diag::note_ovl_candidate_disabled_by_function_cond_attr)
           << Attr->getCond()->getSourceRange() << Attr->getMessage();
       return ExprError();
     }
-
-    SmallVector<DiagnoseIfAttr *, 4> Nonfatal;
-    if (const DiagnoseIfAttr *Attr = checkArgDependentDiagnoseIf(
-            Method, Args, Nonfatal, false, MemE->getBase())) {
-      emitDiagnoseIfDiagnostic(MemE->getMemberLoc(), Attr);
-      return ExprError();
-    }
-
-    for (const auto *Attr : Nonfatal)
-      emitDiagnoseIfDiagnostic(MemE->getMemberLoc(), Attr);
   }
 
   if ((isa<CXXConstructorDecl>(CurContext) || 
        isa<CXXDestructorDecl>(CurContext)) && 
       TheCall->getMethodDecl()->isPure()) {
     const CXXMethodDecl *MD = TheCall->getMethodDecl();
 
     if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
 
   LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
   LookupQualifiedName(R, Record->getDecl());
   R.suppressDiagnostics();
 
   for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
        Oper != OperEnd; ++Oper) {
     AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
-                       Object.get()->Classify(Context),
-                       Object.get(), Args, CandidateSet,
-                       /*SuppressUserConversions=*/ false);
+                       Object.get()->Classify(Context), Args, CandidateSet,
+                       /*SuppressUserConversions=*/false);
   }
 
   // C++ [over.call.object]p2:
   //   In addition, for each (non-explicit in C++0x) conversion function 
   //   declared in T of the form
   //
   //        operator conversion-type-id () cv-qualifier;
   //
Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
 
   LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
   LookupQualifiedName(R, BaseRecord->getDecl());
   R.suppressDiagnostics();
 
   for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
        Oper != OperEnd; ++Oper) {
     AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
-                       Base, None, CandidateSet,
-                       /*SuppressUserConversions=*/false);
+                       None, CandidateSet, /*SuppressUserConversions=*/false);
   }
 
   bool HadMultipleCandidates = (CandidateSet.size() > 1);
 
   // Perform overload resolution.
   OverloadCandidateSet::iterator Best;
   switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
   case OR_Success:
Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
   QualType ResultTy = Method->getReturnType();
   ExprValueKind VK = Expr::getValueKindForType(ResultTy);
   ResultTy = ResultTy.getNonLValueExprType(Context);
   CXXOperatorCallExpr *TheCall =
     new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.get(),
                                       Base, ResultTy, VK, OpLoc, false);
 
   if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
-          return ExprError();
 
+  if (CheckFunctionCall(Method, TheCall,
+                        Method->getType()->castAs<FunctionProtoType>()))
+    return ExprError();
+
   return MaybeBindToTemporary(TheCall);
 }
 
 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
 /// a literal operator described by the provided lookup results.
 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
                                           DeclarationNameInfo &SuffixInfo,
                                           ArrayRef<Expr*> Args,

cfe/trunk/test/Sema/diagnose_if.c

void runVariable() {
   abs(m);
 
   int (*pabs)(int) = abs;
   pabs = &abs;
 }
 
 #define _overloadable __attribute__((overloadable))
 
-int ovl1(const char *n) _overloadable _diagnose_if(n, "oh no", "error"); // expected-note{{oh no}}
-int ovl1(void *m) _overloadable; // expected-note{{candidate function}}
+int ovl1(const char *n) _overloadable _diagnose_if(n, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+int ovl1(void *m) _overloadable;
 
 int ovl2(const char *n) _overloadable _diagnose_if(n, "oh no", "error"); // expected-note{{candidate function}}
 int ovl2(char *m) _overloadable; // expected-note{{candidate function}}
 void overloadsYay() {
   ovl1((void *)0);
-  ovl1(""); // expected-error{{call to unavailable function}}
+  ovl1(""); // expected-error{{oh no}}
 
   ovl2((void *)0); // expected-error{{ambiguous}}
 }
 
 void errorWarnDiagnose1() _diagnose_if(1, "oh no", "error") // expected-note{{from 'diagnose_if'}}
   _diagnose_if(1, "nop", "warning");
 void errorWarnDiagnose2() _diagnose_if(1, "oh no", "error") // expected-note{{from 'diagnose_if'}}
   _diagnose_if(1, "nop", "error");

cfe/trunk/test/SemaCXX/diagnose_if.cpp

 // RUN: %clang_cc1 %s -verify -fno-builtin -std=c++14
 
 #define _diagnose_if(...) __attribute__((diagnose_if(__VA_ARGS__)))
 
+using size_t = unsigned long;
+
 namespace type_dependent {
 template <typename T>
 void neverok() _diagnose_if(!T(), "oh no", "error") {} // expected-note 4{{from 'diagnose_if'}}
 
 template <typename T>
 void alwaysok() _diagnose_if(T(), "oh no", "error") {}
 
 template <typename T>
void runAll() {
   neverwarn<short>();
   {
     void (*pok)() = neverwarn<int>;
     pok = &neverwarn<int>;
   }
 }
 
 template <typename T>
-void errorIf(T a) _diagnose_if(T() != a, "oh no", "error") {} // expected-note {{candidate disabled: oh no}}
+void errorIf(T a) _diagnose_if(T() != a, "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
 
 template <typename T>
-void warnIf(T a) _diagnose_if(T() != a, "oh no", "warning") {} // expected-note {{from 'diagnose_if'}}
+void warnIf(T a) _diagnose_if(T() != a, "oh no", "warning") {} // expected-note{{from 'diagnose_if'}}
 
 void runIf() {
   errorIf(0);
-  errorIf(1); // expected-error{{call to unavailable function}}
+  errorIf(1); // expected-error{{oh no}}
 
   warnIf(0);
   warnIf(1); // expected-warning{{oh no}}
 }
 }
 
 namespace value_dependent {
 template <int N>
void runAll() {
   neverwarn<1>();
   {
     void (*pok)() = neverwarn<0>;
     pok = &neverwarn<0>;
   }
 }
 
 template <int N>
-void errorIf(int a) _diagnose_if(N != a, "oh no", "error") {} // expected-note {{candidate disabled: oh no}}
+void errorIf(int a) _diagnose_if(N != a, "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
 
 template <int N>
-void warnIf(int a) _diagnose_if(N != a, "oh no", "warning") {} // expected-note {{from 'diagnose_if'}}
+void warnIf(int a) _diagnose_if(N != a, "oh no", "warning") {} // expected-note{{from 'diagnose_if'}}
 
 void runIf() {
   errorIf<0>(0);
-  errorIf<0>(1); // expected-error{{call to unavailable function}}
+  errorIf<0>(1); // expected-error{{oh no}}
 
   warnIf<0>(0);
   warnIf<0>(1); // expected-warning{{oh no}}
 }
 }
 
 namespace no_overload_interaction {
 void foo(int) _diagnose_if(1, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
 void foo(short);
 
 void bar(int);
 void bar(short) _diagnose_if(1, "oh no", "error");
 
-void fooArg(int a) _diagnose_if(a, "oh no", "error"); // expected-note{{candidate disabled: oh no}}
-void fooArg(short); // expected-note{{candidate function}}
+void fooArg(int a) _diagnose_if(a, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+void fooArg(short);
 
 void barArg(int);
 void barArg(short a) _diagnose_if(a, "oh no", "error");
 
 void runAll() {
   foo(1); // expected-error{{oh no}}
   bar(1);
 
-  fooArg(1); // expected-error{{call to unavailable function}}
+  fooArg(1); // expected-error{{oh no}}
   barArg(1);
 
   auto p = foo; // expected-error{{incompatible initializer of type '<overloaded function type>'}}
 }
 }
 
 namespace with_default_args {
 void foo(int a = 0) _diagnose_if(a, "oh no", "warning"); // expected-note 1{{from 'diagnose_if'}}

 }
 
 namespace class_template {
 template <typename T>
 struct Errors {
   void foo(int i) _diagnose_if(i, "bad i", "error"); // expected-note{{from 'diagnose_if'}}
   void bar(int i) _diagnose_if(i != T(), "bad i", "error"); // expected-note{{from 'diagnose_if'}}
 
-  void fooOvl(int i) _diagnose_if(i, "int bad i", "error"); // expected-note 2{{int bad i}}
-  void fooOvl(short i) _diagnose_if(i, "short bad i", "error"); // expected-note 2{{short bad i}}
+  void fooOvl(int i) _diagnose_if(i, "int bad i", "error"); // expected-note{{from 'diagnose_if'}}
+  void fooOvl(short i) _diagnose_if(i, "short bad i", "error"); // expected-note{{from 'diagnose_if'}}
 
-  void barOvl(int i) _diagnose_if(i != T(), "int bad i", "error"); // expected-note 2{{int bad i}}
-  void barOvl(short i) _diagnose_if(i != T(), "short bad i", "error"); // expected-note 2{{short bad i}}
+  void barOvl(int i) _diagnose_if(i != T(), "int bad i", "error"); // expected-note{{from 'diagnose_if'}}
+  void barOvl(short i) _diagnose_if(i != T(), "short bad i", "error"); // expected-note{{from 'diagnose_if'}}
 };
 
 void runErrors() {
   Errors<int>().foo(0);
   Errors<int>().foo(1); // expected-error{{bad i}}
 
   Errors<int>().bar(0);
   Errors<int>().bar(1); // expected-error{{bad i}}
 
   Errors<int>().fooOvl(0);
-  Errors<int>().fooOvl(1); // expected-error{{call to unavailable}}
+  Errors<int>().fooOvl(1); // expected-error{{int bad i}}
   Errors<int>().fooOvl(short(0));
-  Errors<int>().fooOvl(short(1)); // expected-error{{call to unavailable}}
+  Errors<int>().fooOvl(short(1)); // expected-error{{short bad i}}
 
   Errors<int>().barOvl(0);
-  Errors<int>().barOvl(1); // expected-error{{call to unavailable}}
+  Errors<int>().barOvl(1); // expected-error{{int bad i}}
   Errors<int>().barOvl(short(0));
-  Errors<int>().barOvl(short(1)); // expected-error{{call to unavailable}}
+  Errors<int>().barOvl(short(1)); // expected-error{{short bad i}}
 }
 
 template <typename T>
 struct Warnings {
   void foo(int i) _diagnose_if(i, "bad i", "warning"); // expected-note{{from 'diagnose_if'}}
   void bar(int i) _diagnose_if(i != T(), "bad i", "warning"); // expected-note{{from 'diagnose_if'}}
 
   void fooOvl(int i) _diagnose_if(i, "int bad i", "warning"); // expected-note{{from 'diagnose_if'}}
void runAll() {
   Foo<int>().baz(1); // expected-error{{bad i}}
 }
 }
 
 namespace late_constexpr {
 constexpr int foo();
 constexpr int foo(int a);
 
-void bar() _diagnose_if(foo(), "bad foo", "error"); // expected-note{{from 'diagnose_if'}} expected-note{{not viable: requires 0 arguments}}
-void bar(int a) _diagnose_if(foo(a), "bad foo", "error"); // expected-note{{bad foo}}
+void bar() _diagnose_if(foo(), "bad foo", "error"); // expected-note{{from 'diagnose_if'}}
+void bar(int a) _diagnose_if(foo(a), "bad foo", "error"); // expected-note{{from 'diagnose_if'}}
 
 void early() {
   bar();
   bar(0);
   bar(1);
 }
 
 constexpr int foo() { return 1; }
 constexpr int foo(int a) { return a; }
 
 void late() {
   bar(); // expected-error{{bad foo}}
   bar(0);
-  bar(1); // expected-error{{call to unavailable function}}
+  bar(1); // expected-error{{bad foo}}
 }
 }
 
 namespace late_parsed {
 struct Foo {
   int i;
   constexpr Foo(int i): i(i) {}
   constexpr bool isFooable() const { return i; }
 
   void go() const _diagnose_if(isFooable(), "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
-  operator int() const _diagnose_if(isFooable(), "oh no", "error") { return 1; } // expected-note{{oh no}}
+  operator int() const _diagnose_if(isFooable(), "oh no", "error") { return 1; } // expected-note{{from 'diagnose_if'}}
 
-  void go2() const _diagnose_if(isFooable(), "oh no", "error") // expected-note{{oh no}}
+  void go2() const _diagnose_if(isFooable(), "oh no", "error") // expected-note{{from 'diagnose_if'}}
       __attribute__((enable_if(true, ""))) {}
-  void go2() const _diagnose_if(isFooable(), "oh no", "error") {} // expected-note{{oh no}}
+  void go2() const _diagnose_if(isFooable(), "oh no", "error") {}
 
   constexpr int go3() const _diagnose_if(isFooable(), "oh no", "error")
       __attribute__((enable_if(true, ""))) {
     return 1;
   }
 
   constexpr int go4() const _diagnose_if(isFooable(), "oh no", "error") {
     return 1;
   }
   constexpr int go4() const _diagnose_if(isFooable(), "oh no", "error")
       __attribute__((enable_if(true, ""))) {
     return 1;
   }
 
   // We hope to support emitting these errors in the future. For now, though...
   constexpr int runGo() const {
     return go3() + go4();
   }
 };
 
-void go(const Foo &f) _diagnose_if(f.isFooable(), "oh no", "error") {} // expected-note{{oh no}}
+void go(const Foo &f) _diagnose_if(f.isFooable(), "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
 
 void run() {
   Foo(0).go();
   Foo(1).go(); // expected-error{{oh no}}
 
   (void)int(Foo(0));
-  (void)int(Foo(1)); // expected-error{{uses deleted function}}
+  (void)int(Foo(1)); // expected-error{{oh no}}
 
   Foo(0).go2();
-  Foo(1).go2(); // expected-error{{call to unavailable member function}}
+  Foo(1).go2(); // expected-error{{oh no}}
 
   go(Foo(0));
-  go(Foo(1)); // expected-error{{call to unavailable function}}
+  go(Foo(1)); // expected-error{{oh no}}
 }
 }
 
 namespace member_templates {
 struct Foo {
   int i;
   constexpr Foo(int i): i(i) {}
   constexpr bool bad() const { return i; }
 
-  template <typename T> T getVal() _diagnose_if(bad(), "oh no", "error") { // expected-note{{oh no}}
+  template <typename T> T getVal() _diagnose_if(bad(), "oh no", "error") { // expected-note{{from 'diagnose_if'}}
     return T();
   }
 
   template <typename T>
-  constexpr T getVal2() const _diagnose_if(bad(), "oh no", "error") { // expected-note{{oh no}}
+  constexpr T getVal2() const _diagnose_if(bad(), "oh no", "error") { // expected-note{{from 'diagnose_if'}}
     return T();
   }
 
   template <typename T>
-  constexpr operator T() const _diagnose_if(bad(), "oh no", "error") { // expected-note{{oh no}}
+  constexpr operator T() const _diagnose_if(bad(), "oh no", "error") { // expected-note{{from 'diagnose_if'}}
     return T();
   }
 
   // We hope to support emitting these errors in the future.
   int run() { return getVal<int>() + getVal2<int>() + int(*this); }
 };
 
 void run() {
   Foo(0).getVal<int>();
-  Foo(1).getVal<int>(); // expected-error{{call to unavailable member function}}
+  Foo(1).getVal<int>(); // expected-error{{oh no}}
 
   Foo(0).getVal2<int>();
-  Foo(1).getVal2<int>(); // expected-error{{call to unavailable member function}}
+  Foo(1).getVal2<int>(); // expected-error{{oh no}}
 
   (void)int(Foo(0));
-  (void)int(Foo(1)); // expected-error{{uses deleted function}}
+  (void)int(Foo(1)); // expected-error{{oh no}}
 }
 }
 
 namespace special_member_operators {
 struct Bar { int j; };
 struct Foo {
   int i;
   constexpr Foo(int i): i(i) {}
   constexpr bool bad() const { return i; }
-  const Bar *operator->() const _diagnose_if(bad(), "oh no", "error") { // expected-note{{oh no}}
+  const Bar *operator->() const _diagnose_if(bad(), "oh no", "error") { // expected-note{{from 'diagnose_if'}}
     return nullptr;
   }
-  void operator()() const _diagnose_if(bad(), "oh no", "error") {} // expected-note{{oh no}}
+  void operator()() const _diagnose_if(bad(), "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
 };
 
 struct ParenOverload {
   int i;
   constexpr ParenOverload(int i): i(i) {}
   constexpr bool bad() const { return i; }
-  void operator()(double) const _diagnose_if(bad(), "oh no", "error") {} // expected-note 2{{oh no}}
-  void operator()(int) const _diagnose_if(bad(), "oh no", "error") {} // expected-note 2{{oh no}}
+  void operator()(double) const _diagnose_if(bad(), "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
+  void operator()(int) const _diagnose_if(bad(), "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
 };
 
 struct ParenTemplate {
   int i;
   constexpr ParenTemplate(int i): i(i) {}
   constexpr bool bad() const { return i; }
   template <typename T>
-  void operator()(T) const _diagnose_if(bad(), "oh no", "error") {} // expected-note 2{{oh no}}
+  void operator()(T) const _diagnose_if(bad(), "oh no", "error") {} // expected-note 2{{from 'diagnose_if'}}
 };
 
 void run() {
   (void)Foo(0)->j;
-  (void)Foo(1)->j; // expected-error{{selected unavailable operator '->'}}
+  (void)Foo(1)->j; // expected-error{{oh no}}
 
   Foo(0)();
-  Foo(1)(); // expected-error{{unavailable function call operator}}
+  Foo(1)(); // expected-error{{oh no}}
 
   ParenOverload(0)(1);
   ParenOverload(0)(1.);
 
-  ParenOverload(1)(1); // expected-error{{unavailable function call operator}}
-  ParenOverload(1)(1.); // expected-error{{unavailable function call operator}}
+  ParenOverload(1)(1); // expected-error{{oh no}}
+  ParenOverload(1)(1.); // expected-error{{oh no}}
 
   ParenTemplate(0)(1);
   ParenTemplate(0)(1.);
 
-  ParenTemplate(1)(1); // expected-error{{unavailable function call operator}}
-  ParenTemplate(1)(1.); // expected-error{{unavailable function call operator}}
+  ParenTemplate(1)(1); // expected-error{{oh no}}
+  ParenTemplate(1)(1.); // expected-error{{oh no}}
 }
 
 void runLambda() {
-  auto L1 = [](int i) _diagnose_if(i, "oh no", "error") {}; // expected-note{{oh no}} expected-note{{conversion candidate}}
+  auto L1 = [](int i) _diagnose_if(i, "oh no", "error") {}; // expected-note{{from 'diagnose_if'}}
   L1(0);
-  L1(1); // expected-error{{call to unavailable function call}}
+  L1(1); // expected-error{{oh no}}
+}
+
+struct Brackets {
+  int i;
+  constexpr Brackets(int i): i(i) {}
+  void operator[](int) _diagnose_if(i == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+    _diagnose_if(i == 2, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+};
+
+void runBrackets(int i) {
+  Brackets{0}[i];
+  Brackets{1}[i]; // expected-warning{{oh no}}
+  Brackets{2}[i]; // expected-error{{oh no}}
+}
+
+struct Unary {
+  int i;
+  constexpr Unary(int i): i(i) {}
+  void operator+() _diagnose_if(i == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+    _diagnose_if(i == 2, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+};
+
+void runUnary() {
+  +Unary{0};
+  +Unary{1}; // expected-warning{{oh no}}
+  +Unary{2}; // expected-error{{oh no}}
+}
+
+struct PostInc {
+  void operator++(int i) _diagnose_if(i == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+    _diagnose_if(i == 2, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+};
+
+void runPostInc() {
+  PostInc{}++;
+  PostInc{}.operator++(1); // expected-warning{{oh no}}
+  PostInc{}.operator++(2); // expected-error{{oh no}}
 }
 }
 
 namespace ctors {
 struct Foo {
   int I;
   constexpr Foo(int I): I(I) {}
 
-  constexpr const Foo &operator=(const Foo &) const // expected-note 2{{disabled: oh no}}
-      _diagnose_if(I, "oh no", "error") {
+  constexpr const Foo &operator=(const Foo &) const
+      _diagnose_if(I, "oh no", "error") {  // expected-note{{from 'diagnose_if'}}
     return *this;
   }
 
-  constexpr const Foo &operator=(const Foo &&) const // expected-note{{disabled: oh no}} expected-note{{no known conversion}}
-      _diagnose_if(I, "oh no", "error") {
+  constexpr const Foo &operator=(const Foo &&) const
+      _diagnose_if(I, "oh no", "error") { // expected-note{{from 'diagnose_if'}}
     return *this;
   }
 };
 
+struct Bar {
+  int I;
+  constexpr Bar(int I) _diagnose_if(I == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+    _diagnose_if(I == 2, "oh no", "error"): I(I) {} // expected-note{{from 'diagnose_if'}}
+};
+
 void run() {
   constexpr Foo F{0};
   constexpr Foo F2{1};
 
-  F2 = F; // expected-error{{selected unavailable operator}}
-  F2 = Foo{2}; // expected-error{{selected unavailable operator}}
+  F2 = F; // expected-error{{oh no}}
+  F2 = Foo{2}; // expected-error{{oh no}}
+
+  Bar{0};
+  Bar{1}; // expected-warning{{oh no}}
+  Bar{2}; // expected-error{{oh no}}
+}
+}
+
+namespace ref_init {
+struct Bar {};
+struct Baz {};
+struct Foo {
+  int i;
+  constexpr Foo(int i): i(i) {}
+  operator const Bar &() const _diagnose_if(i, "oh no", "warning"); // expected-note{{from 'diagnose_if'}}
+  operator const Baz &() const _diagnose_if(i, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+};
+void fooBar(const Bar &b);
+void fooBaz(const Baz &b);
+
+void run() {
+  fooBar(Foo{0});
+  fooBar(Foo{1}); // expected-warning{{oh no}}
+  fooBaz(Foo{0});
+  fooBaz(Foo{1}); // expected-error{{oh no}}
+}
+}
+
+namespace udl {
+void operator""_fn(char c)_diagnose_if(c == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+    _diagnose_if(c == 2, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+
+void run() {
+  '\0'_fn;
+  '\1'_fn; // expected-warning{{oh no}}
+  '\2'_fn; // expected-error{{oh no}}
+}
+}
+
+namespace PR31638 {
+struct String {
+  String(char const* __s) _diagnose_if(__s == nullptr, "oh no ptr", "warning"); // expected-note{{from 'diagnose_if'}}
+  String(int __s) _diagnose_if(__s != 0, "oh no int", "warning"); // expected-note{{from 'diagnose_if'}}
+};
+
+void run() {
+  String s(nullptr); // expected-warning{{oh no ptr}}
+  String ss(42); // expected-warning{{oh no int}}
+}
+}
+
+namespace PR31639 {
+struct Foo {
+  Foo(int I) __attribute__((diagnose_if(I, "oh no", "error"))); // expected-note{{from 'diagnose_if'}}
+};
+
+void bar() { Foo f(1); } // expected-error{{oh no}}
+}
+
+namespace user_defined_conversion {
+struct Foo {
+  int i;
+  constexpr Foo(int i): i(i) {}
+  operator size_t() const _diagnose_if(i == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+      _diagnose_if(i == 2, "oh no", "error"); // expected-note{{from 'diagnose_if'}}
+};
+
+void run() {
+  // `new T[N]`, where N is implicitly convertible to size_t, calls
+  // PerformImplicitConversion directly. This lets us test the diagnostic logic
+  // in PerformImplicitConversion.
+  new int[Foo{0}];
+  new int[Foo{1}]; // expected-warning{{oh no}}
+  new int[Foo{2}]; // expected-error{{oh no}}
+}
+}
+
+namespace std {
+  template <typename T>
+  struct initializer_list {
+    const T *ptr;
+    size_t elems;
+
+    constexpr size_t size() const { return elems; }
+  };
+}
+
+namespace initializer_lists {
+struct Foo {
+  Foo(std::initializer_list<int> l)
+    _diagnose_if(l.size() == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+    _diagnose_if(l.size() == 2, "oh no", "error") {} // expected-note{{from 'diagnose_if'}}
+};
+
+void run() {
+  Foo{std::initializer_list<int>{}};
+  Foo{std::initializer_list<int>{1}}; // expected-warning{{oh no}}
+  Foo{std::initializer_list<int>{1, 2}}; // expected-error{{oh no}}
+  Foo{std::initializer_list<int>{1, 2, 3}};
+}
+}
+
+namespace range_for_loop {
+  namespace adl {
+    struct Foo {
+      int i;
+      constexpr Foo(int i): i(i) {}
+    };
+    void **begin(const Foo &f) _diagnose_if(f.i, "oh no", "warning");
+    void **end(const Foo &f) _diagnose_if(f.i, "oh no", "warning");
+
+    struct Bar {
+      int i;
+      constexpr Bar(int i): i(i) {}
+    };
+    void **begin(const Bar &b) _diagnose_if(b.i, "oh no", "error");
+    void **end(const Bar &b) _diagnose_if(b.i, "oh no", "error");
+  }
+
+  void run() {
+    for (void *p : adl::Foo(0)) {}
+    // FIXME: This should emit diagnostics. It seems that our constexpr
+    // evaluator isn't able to evaluate `adl::Foo(1)` as a constant, though.
+    for (void *p : adl::Foo(1)) {}
+
+    for (void *p : adl::Bar(0)) {}
+    // FIXME: Same thing.
+    for (void *p : adl::Bar(1)) {}
+  }
+}
+
+namespace operator_new {
+struct Foo {
+  int j;
+  static void *operator new(size_t i) _diagnose_if(i, "oh no", "warning");
+};
+
+struct Bar {
+  int j;
+  static void *operator new(size_t i) _diagnose_if(!i, "oh no", "warning");
+};
+
+void run() {
+  // FIXME: This should emit a diagnostic.
+  new Foo();
+  // This is here because we sometimes pass a dummy argument `operator new`. We
+  // should ignore this, rather than complaining about it.
+  new Bar();
+}
+}
+
+namespace contextual_implicit_conv {
+struct Foo {
+  int i;
+  constexpr Foo(int i): i(i) {}
+  constexpr operator int() const _diagnose_if(i == 1, "oh no", "warning") // expected-note{{from 'diagnose_if'}}
+      _diagnose_if(i == 2, "oh no", "error") { // expected-note{{from 'diagnose_if'}}
+    return i;
+  }
+};
+
+void run() {
+  switch (constexpr Foo i = 0) { default: break; }
+  switch (constexpr Foo i = 1) { default: break; } // expected-warning{{oh no}}
+  switch (constexpr Foo i = 2) { default: break; } // expected-error{{oh no}}
 }
 }