Add a special note for overload resolution when an initializer list argument

cannot be converted.
This is in preparation for overload resolution of initializer lists.
Currently, you will always get this message when you try to pass an init
list to an overloaded function.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140461 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 5da5288cca0fbd3e6bb67ef10f96328dde84cfa9..6f3e151e098d5af60c94b57b500176363ef45469 100644 (file)
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1733,6 +1733,16 @@ def note_ovl_candidate_bad_conv_incomplete : Note<"candidate "
     "function (the implicit move assignment operator)|"
     "constructor (inherited)}0%1 "
     "not viable: cannot convert argument of incomplete type %2 to %3">;
+def note_ovl_candidate_bad_list_argument : Note<"candidate "
+    "%select{function|function|constructor|"
+    "function |function |constructor |"
+    "constructor (the implicit default constructor)|"
+    "constructor (the implicit copy constructor)|"
+    "constructor (the implicit move constructor)|"
+    "function (the implicit copy assignment operator)|"
+    "function (the implicit move assignment operator)|"
+    "constructor (inherited)}0%1 "
+    "not viable: cannot convert initializer list argument to %3">;
 def note_ovl_candidate_bad_overload : Note<"candidate "
     "%select{function|function|constructor|"
     "function |function |constructor |"

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 513990e177fb31e7a73065faaeb234cf07848c2e..c2bf9d3848fb8719975a25e57f76fbd57ac08476 100644 (file)
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -6915,6 +6915,17 @@ void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) {
     return;
   }
 
+  // Special diagnostic for failure to convert an initializer list, since
+  // telling the user that it has type void is not useful.
+  if (FromExpr && isa<InitListExpr>(FromExpr)) {
+    S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
+      << (unsigned) FnKind << FnDesc
+      << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
+      << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
+    MaybeEmitInheritedConstructorNote(S, Fn);
+    return;
+  }
+
   // Diagnose references or pointers to incomplete types differently,
   // since it's far from impossible that the incompleteness triggered
   // the failure.