PR c++/60223 - ICE with T{} in non-deduced context.

	* pt.c (unify): Allow COMPOUND_LITERAL_P in a non-deduced context.

	* g++.dg/cpp0x/nondeduced1.C: New test.
	* g++.dg/cpp0x/nondeduced2.C: New test.
	* g++.dg/cpp0x/nondeduced3.C: New test.
	* g++.dg/cpp0x/nondeduced4.C: New test.

From-SVN: r272571

gcc/cp/ChangeLog

 2019-06-21  Marek Polacek  <polacek@redhat.com>
 
+	PR c++/60223 - ICE with T{} in non-deduced context.
+	* pt.c (unify): Allow COMPOUND_LITERAL_P in a non-deduced context.
+
 	PR c++/64235 - missing syntax error with invalid alignas.
 	* parser.c (cp_parser_std_attribute_spec): Commit to tentative parse
 	if there's a missing close paren.

gcc/cp/pt.c

@@ -22786,7 +22786,9 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
       /* An unresolved overload is a nondeduced context.  */
       if (is_overloaded_fn (parm) || type_unknown_p (parm))
 	return unify_success (explain_p);
-      gcc_assert (EXPR_P (parm) || TREE_CODE (parm) == TRAIT_EXPR);
+      gcc_assert (EXPR_P (parm)
+		  || COMPOUND_LITERAL_P (parm)
+		  || TREE_CODE (parm) == TRAIT_EXPR);
     expr:
       /* We must be looking at an expression.  This can happen with
 	 something like:
@@ -22794,15 +22796,19 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
 	   template <int I>
 	   void foo(S<I>, S<I + 2>);
 
-	 This is a "nondeduced context":
+	 or
+
+	   template<typename T>
+	   void foo(A<T, T{}>);
+
+	 This is a "non-deduced context":
 
 	   [deduct.type]
 
-	   The nondeduced contexts are:
+	   The non-deduced contexts are:
 
-	   --A type that is a template-id in which one or more of
-	     the template-arguments is an expression that references
-	     a template-parameter.
+	   --A non-type template argument or an array bound in which
+	     a subexpression references a template parameter.
 
 	 In these cases, we assume deduction succeeded, but don't
 	 actually infer any unifications.  */

gcc/testsuite/ChangeLog

-2019-06-19  Marek Polacek  <polacek@redhat.com>
+2019-06-21  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/60223 - ICE with T{} in non-deduced context.
+	* g++.dg/cpp0x/nondeduced1.C: New test.
+	* g++.dg/cpp0x/nondeduced2.C: New test.
+	* g++.dg/cpp0x/nondeduced3.C: New test.
+	* g++.dg/cpp0x/nondeduced4.C: New test.
 
 	PR c++/64235 - missing syntax error with invalid alignas.
 	* g++.dg/parse/alignas1.C: New test.

gcc/testsuite/g++.dg/cpp0x/nondeduced1.C

+// PR c++/60223
+// { dg-do compile { target c++11 } }
+
+template<typename T, T = T{}>
+struct A { };
+
+template<typename T>
+void foo(A<T> a);
+
+void bar()
+{
+  foo(A<char, char{}>());
+  foo(A<char>());
+  foo<>(A<char>());
+  foo<>(A<char, char{}>());
+}

gcc/testsuite/g++.dg/cpp0x/nondeduced2.C

+// PR c++/60223
+// { dg-do compile { target c++11 } }
+
+template<typename T, T>
+struct A { };
+
+template<typename T>
+void foo(A<T, T{}>);
+
+void bar()
+{
+  foo(A<char, char{}>());
+  foo<>(A<char, char{}>());
+}

gcc/testsuite/g++.dg/cpp0x/nondeduced3.C

+// PR c++/60223
+// { dg-do compile { target c++11 } }
+
+template<typename T, T = T{1}>
+struct A { };
+
+template<typename T>
+void foo(A<T> a);
+
+void bar()
+{
+  foo(A<char>());
+  foo(A<char, char{1}>());
+  foo<>(A<char>());
+  foo<>(A<char, char{1}>());
+}

gcc/testsuite/g++.dg/cpp0x/nondeduced4.C

+// PR c++/60223
+// { dg-do compile { target c++11 } }
+
+template<typename T>
+struct A { };
+
+template<typename T>
+void foo(A<T>, T = T{});
+
+void bar()
+{
+  foo(A<int>());
+}