If a function decl cannot be merged, mark it as invalid.

Clang currently crashes on

    class C {
      C() = default;
      C() = delete;
    };

My cunning plan for fixing this was to change the `if (!FnD)` in
Parser::ParseCXXInlineMethodDef() to `if (!FnD || FnD->isInvalidDecl)` – but
alas, the second constructor decl wasn't marked as invalid.  This lets
Sema::MergeFunctionDecl() return true on function redeclarations, which leads
to them being marked invalid.

This also improves error messages when functions are redeclared.

llvm-svn: 226365

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 9b9a6afbfd8..9aa1d9ca83c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2761,6 +2761,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
             << New << New->getType();
         }
         Diag(OldLocation, PrevDiag) << Old << Old->getType();
+        return true;
 
       // Complain if this is an explicit declaration of a special
       // member that was initially declared implicitly.