From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Tue, 9 Oct 2018 18:49:22 +0000 (+0000)
Subject: PR39231: fix null dereference when diagnosing deduction failure due to
X-Git-Tag: llvmorg-8.0.0-rc1~6955
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e54d9525ad594a0084f003244ad56982c412c4b0;p=platform%2Fupstream%2Fllvm.git

PR39231: fix null dereference when diagnosing deduction failure due to
conflicting values for a non-type pack.

llvm-svn: 344070
---

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index f4ec04a..a5a51d5 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -9984,7 +9984,7 @@ static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
           DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
       QualType T2 =
           DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
-      if (!S.Context.hasSameType(T1, T2)) {
+      if (!T1.isNull() && !T2.isNull() && !S.Context.hasSameType(T1, T2)) {
         S.Diag(Templated->getLocation(),
                diag::note_ovl_candidate_inconsistent_deduction_types)
           << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1
diff --git a/clang/test/SemaTemplate/temp_arg_pack.cpp b/clang/test/SemaTemplate/temp_arg_pack.cpp
index b79dca7..26e3f6b 100644
--- a/clang/test/SemaTemplate/temp_arg_pack.cpp
+++ b/clang/test/SemaTemplate/temp_arg_pack.cpp
@@ -6,3 +6,19 @@ namespace deduce_pack_non_pack {
   template <typename T> void g(C<A<T>>); // expected-note {{candidate template ignored: deduced type 'C<A<[...], (no argument)>>' of 1st parameter does not match adjusted type 'C<A<[...], int>>' of argument [with T = bool]}}
   void h(C<A<bool, int>> &x) { g(x); } // expected-error {{no matching function}}
 }
+
+namespace pr39231 {
+  template<typename T, T ...V> struct integer_sequence {};
+
+  template <typename T, T... A, T... B>
+  int operator^(integer_sequence<T, A...> a, // expected-note {{deduced conflicting values for parameter 'A' (<1, 2, 3> vs. <4, 5, 6>)}}
+                integer_sequence<T, A...> b);
+
+  int v = integer_sequence<int, 1, 2, 3>{} ^ integer_sequence<int, 4, 5, 6>{}; // expected-error {{invalid operands}}
+
+  template <typename T, T... A, T... B>
+  integer_sequence<T, A + B...> operator+(integer_sequence<T, A...> a,
+                                          integer_sequence<T, B...> b);
+  integer_sequence<int, 5, 7, 9> w =
+      integer_sequence<int, 1, 2, 3>{} + integer_sequence<int, 4, 5, 6>{};
+}