[Sema] Deduplicate some availability checking logic

Before this commit, we emit unavailable errors for calls to functions during
overload resolution, and for references to all other declarations in
DiagnoseUseOfDecl. The early checks during overload resolution aren't as good as
the DiagnoseAvailabilityOfDecl based checks, as they error on the code from
PR40991. This commit fixes this by removing the early checking.

llvm.org/PR40991
rdar://48564179

Differential revision: https://reviews.llvm.org/D59394

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@356599 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 50 deletions

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 2409acd44f..2f6f94313b 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -1229,24 +1229,6 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
   return false;
 }
 
-/// Checks availability of the function depending on the current
-/// function context. Inside an unavailable function, unavailability is ignored.
-///
-/// \returns true if \arg FD is unavailable and current context is inside
-/// an available function, false otherwise.
-bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
-  if (!FD->isUnavailable())
-    return false;
-
-  // Walk up the context of the caller.
-  Decl *C = cast<Decl>(CurContext);
-  do {
-    if (C->isUnavailable())
-      return false;
-  } while ((C = cast_or_null<Decl>(C->getDeclContext())));
-  return true;
-}
-
 /// Tries a user-defined conversion from From to ToType.
 ///
 /// Produces an implicit conversion sequence for when a standard conversion
@@ -9453,9 +9435,7 @@ OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
   }
 
   // Best is the best viable function.
-  if (Best->Function &&
-      (Best->Function->isDeleted() ||
-       S.isFunctionConsideredUnavailable(Best->Function)))
+  if (Best->Function && Best->Function->isDeleted())
     return OR_Deleted;
 
   if (!EquivalentCands.empty())
@@ -10367,7 +10347,7 @@ static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
 
   // Note deleted candidates, but only if they're viable.
   if (Cand->Viable) {
-    if (Fn->isDeleted() || S.isFunctionConsideredUnavailable(Fn)) {
+    if (Fn->isDeleted()) {
       std::string FnDesc;
       std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
           ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
@@ -12132,9 +12112,7 @@ static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
 
   case OR_Deleted: {
     SemaRef.Diag(Fn->getBeginLoc(), diag::err_ovl_deleted_call)
-        << (*Best)->Function->isDeleted() << ULE->getName()
-        << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function)
-        << Fn->getSourceRange();
+        << ULE->getName() << Fn->getSourceRange();
     CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
 
     // We emitted an error for the unavailable/deleted function call but keep
@@ -12379,10 +12357,7 @@ Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
 
   case OR_Deleted:
     Diag(OpLoc, diag::err_ovl_deleted_oper)
-      << Best->Function->isDeleted()
-      << UnaryOperator::getOpcodeStr(Opc)
-      << getDeletedOrUnavailableSuffix(Best->Function)
-      << Input->getSourceRange();
+        << UnaryOperator::getOpcodeStr(Opc) << Input->getSourceRange();
     CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray,
                                 UnaryOperator::getOpcodeStr(Opc), OpLoc);
     return ExprError();
@@ -12670,10 +12645,8 @@ Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
         return ExprError();
       } else {
         Diag(OpLoc, diag::err_ovl_deleted_oper)
-          << Best->Function->isDeleted()
-          << BinaryOperator::getOpcodeStr(Opc)
-          << getDeletedOrUnavailableSuffix(Best->Function)
-          << Args[0]->getSourceRange() << Args[1]->getSourceRange();
+            << BinaryOperator::getOpcodeStr(Opc) << Args[0]->getSourceRange()
+            << Args[1]->getSourceRange();
       }
       CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
                                   BinaryOperator::getOpcodeStr(Opc), OpLoc);
@@ -12842,11 +12815,8 @@ Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
 
     case OR_Deleted:
       Diag(LLoc, diag::err_ovl_deleted_oper)
-        << Best->Function->isDeleted() << "[]"
-        << getDeletedOrUnavailableSuffix(Best->Function)
-        << Args[0]->getSourceRange() << Args[1]->getSourceRange();
-      CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
-                                  "[]", LLoc);
+          << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange();
+      CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, "[]", LLoc);
       return ExprError();
     }
 
@@ -13031,10 +13001,7 @@ Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
 
     case OR_Deleted:
       Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
-        << Best->Function->isDeleted()
-        << DeclName
-        << getDeletedOrUnavailableSuffix(Best->Function)
-        << MemExprE->getSourceRange();
+          << DeclName << MemExprE->getSourceRange();
       CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
       // FIXME: Leaking incoming expressions!
       return ExprError();
@@ -13258,9 +13225,7 @@ Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
 
   case OR_Deleted:
     Diag(Object.get()->getBeginLoc(), diag::err_ovl_deleted_object_call)
-        << Best->Function->isDeleted() << Object.get()->getType()
-        << getDeletedOrUnavailableSuffix(Best->Function)
-        << Object.get()->getSourceRange();
+        << Object.get()->getType() << Object.get()->getSourceRange();
     CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
     break;
   }
@@ -13488,11 +13453,7 @@ Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
     return ExprError();
 
   case OR_Deleted:
-    Diag(OpLoc,  diag::err_ovl_deleted_oper)
-      << Best->Function->isDeleted()
-      << "->"
-      << getDeletedOrUnavailableSuffix(Best->Function)
-      << Base->getSourceRange();
+    Diag(OpLoc, diag::err_ovl_deleted_oper) << "->" << Base->getSourceRange();
     CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
     return ExprError();
   }