Introduce support for emitting diagnostics (warnings + their notes)

that are suppressed during template argument deduction. This change
queues diagnostics computed during template argument deduction. Then,
if the resulting function template specialization or partial
specialization is chosen by overload resolution or partial ordering
(respectively), we will emit the queued diagnostics at that point. 

This addresses most of PR6784. However, the check for unnamed/local
template arguments (which existed before this change) is still only
skin-deep, and needs to be extended to look deeper into types. It must
be improved to finish PR6784.

llvm-svn: 116373

1 files changed, 11 insertions, 14 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 1437238f3bf..078669a556a 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -5489,6 +5489,7 @@ OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
   //   placement new (5.3.4), as well as non-default initialization (8.5).
   if (Best->Function)
     S.MarkDeclarationReferenced(Loc, Best->Function);
+  
   return OR_Success;
 }
 
@@ -6313,7 +6314,7 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
   // whose type matches exactly.
   llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
   llvm::SmallVector<FunctionDecl *, 4> NonMatches;
-
+  
   bool FoundNonTemplateFunction = false;
   for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
          E = OvlExpr->decls_end(); I != E; ++I) {
@@ -6344,7 +6345,6 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
       //   resulting template argument list is used to generate a single
       //   function template specialization, which is added to the set of
       //   overloaded functions considered.
-      // FIXME: We don't really want to build the specialization here, do we?
       FunctionDecl *Specialization = 0;
       TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc());
       if (TemplateDeductionResult Result
@@ -6355,10 +6355,10 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
       } else {
         // Template argument deduction ensures that we have an exact match.
         // This function template specicalization works.
+        Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl());
         assert(FunctionType
                  == Context.getCanonicalType(Specialization->getType()));
-        Matches.push_back(std::make_pair(I.getPair(),
-                    cast<FunctionDecl>(Specialization->getCanonicalDecl())));
+        Matches.push_back(std::make_pair(I.getPair(), Specialization));
       }
 
       continue;
@@ -6403,10 +6403,11 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
     return 0;
   } else if (Matches.size() == 1) {
     FunctionDecl *Result = Matches[0].second;
-    FoundResult = Matches[0].first;
+    FoundResult = Matches[0].first;    
     MarkDeclarationReferenced(From->getLocStart(), Result);
-    if (Complain)
+    if (Complain) {
       CheckAddressOfMemberAccess(OvlExpr, Matches[0].first);
+    }
     return Result;
   }
 
@@ -6441,10 +6442,8 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
     
     MarkDeclarationReferenced(From->getLocStart(), *Result);
     FoundResult = Matches[Result - MatchesCopy.begin()].first;
-    if (Complain) {
+    if (Complain)
       CheckUnresolvedAccess(*this, OvlExpr, FoundResult);
-      DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc());
-    }
     return cast<FunctionDecl>(*Result);
   }
 
@@ -6464,10 +6463,8 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
   if (Matches.size() == 1) {
     MarkDeclarationReferenced(From->getLocStart(), Matches[0].second);
     FoundResult = Matches[0].first;
-    if (Complain) {
+    if (Complain)
       CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first);
-      DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc());
-    }
     return cast<FunctionDecl>(Matches[0].second);
   }
 
@@ -6543,7 +6540,7 @@ FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) {
 
     Matched = Specialization;
   }
-
+  
   return Matched;
 }
     
@@ -6734,7 +6731,7 @@ Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
   case OR_Success: {
     FunctionDecl *FDecl = Best->Function;
     CheckUnresolvedLookupAccess(ULE, Best->FoundDecl);
-    DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc());
+    DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl, ULE->getNameLoc());
     Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl);
     return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc);
   }