Improve the diagnostic used when an incompatible overload set is passed

as an argument during overload resolution.

llvm-svn: 95057

3 files changed, 26 insertions, 1 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 78b791c971c..b5d378d0e35 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -957,6 +957,13 @@ def note_ovl_candidate_bad_conv_incomplete : Note<"candidate "
     "constructor (the implicit copy constructor)|"
     "function (the implicit copy assignment operator)}0%1 "
     "not viable: cannot convert argument of incomplete type %2 to %3">;
+def note_ovl_candidate_bad_overload : Note<"candidate "
+    "%select{function|function|constructor|"
+    "function |function |constructor |"
+    "constructor (the implicit default constructor)|"
+    "constructor (the implicit copy constructor)|"
+    "function (the implicit copy assignment operator)}0%1"
+    " not viable: no overload of %3 matching %2 for %ordinal4 argument">;
 def note_ovl_candidate_bad_conv : Note<"candidate "
     "%select{function|function|constructor|"
     "function |function |constructor |"
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 1eb5b38889e..83cbce72261 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -4450,6 +4450,24 @@ void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) {
   QualType FromTy = Conv.Bad.getFromType();
   QualType ToTy = Conv.Bad.getToType();
 
+  if (FromTy == S.Context.OverloadTy) {
+    assert(FromExpr);
+    Expr *E = FromExpr->IgnoreParens();
+    if (isa<UnaryOperator>(E))
+      E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
+    DeclarationName Name;
+    if (isa<UnresolvedLookupExpr>(E))
+      Name = cast<UnresolvedLookupExpr>(E)->getName();
+    else
+      Name = cast<UnresolvedMemberExpr>(E)->getMemberName();
+
+    S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
+      << (unsigned) FnKind << FnDesc
+      << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
+      << ToTy << Name << I+1;
+    return;
+  }
+
   // Do some hand-waving analysis to see if the non-viability is due
   // to a qualifier mismatch.
   CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
diff --git a/clang/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp b/clang/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp
index c1fc696baf5..8f919f53159 100644
--- a/clang/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp
+++ b/clang/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.call/p6.cpp
@@ -3,7 +3,7 @@
 namespace test0 {
   // FIXME: this second note is horrible.
   template<class T> void apply(T x, void (*f)(T)) { f(x); } // expected-note 2 {{failed template argument deduction}}\
-  // expected-note {{no known conversion from '<overloaded function type>' to 'void (*)(int)'}}
+  // expected-note {{no overload of 'temp2' matching 'void (*)(int)'}}
 
   template<class A> void temp(A);
   void test0() {