Catch missed uses of function with unsatisfied constraints.

While looking at CA378 I noticed that we weren't properly diagnosing two of
the three erroneous lines in the example.

	* decl2.c (mark_used): Diagnose use of a function with unsatisfied
	constraints here.
	* typeck.c (cp_build_function_call_vec): Not here.

From-SVN: r277860

gcc/cp/ChangeLog

+2019-11-05  Jason Merrill  <jason@redhat.com>
+
+	* decl2.c (mark_used): Diagnose use of a function with unsatisfied
+	constraints here.
+	* typeck.c (cp_build_function_call_vec): Not here.
+
 2019-11-05  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/92370

gcc/cp/decl2.c

@@ -5524,6 +5524,21 @@ mark_used (tree decl, tsubst_flags_t complain)
      directly.  */
   maybe_instantiate_decl (decl);
 
+  if (flag_concepts && TREE_CODE (decl) == FUNCTION_DECL
+      && !constraints_satisfied_p (decl))
+    {
+      if (complain & tf_error)
+	{
+	  auto_diagnostic_group d;
+	  error ("use of function %qD with unsatisfied constraints",
+		 decl);
+	  location_t loc = DECL_SOURCE_LOCATION (decl);
+	  inform (loc, "declared here");
+	  diagnose_constraints (loc, decl, NULL_TREE);
+	}
+      return false;
+    }
+
   if (processing_template_decl || in_template_function ())
     return true;
 

gcc/cp/typeck.c

@@ -3871,26 +3871,6 @@ cp_build_function_call_vec (tree function, vec<tree, va_gc> **params,
 
   if (TREE_CODE (function) == FUNCTION_DECL)
     {
-      /* If the function is a non-template member function
-         or a non-template friend, then we need to check the
-         constraints.
-
-        Note that if overload resolution failed with a single
-        candidate this function will be used to explicitly diagnose
-        the failure for the single call expression. The check is
-        technically redundant since we also would have failed in
-        add_function_candidate. */
-      if (flag_concepts
-          && (complain & tf_error)
-          && !constraints_satisfied_p (function))
-        {
-          auto_diagnostic_group d;
-          error ("cannot call function %qD", function);
-          location_t loc = DECL_SOURCE_LOCATION (function);
-          diagnose_constraints (loc, function, NULL_TREE);
-          return error_mark_node;
-        }
-
       if (!mark_used (function, complain))
 	return error_mark_node;
       fndecl = function;

gcc/testsuite/g++.dg/concepts/dr1430.C

@@ -41,6 +41,6 @@ requires Similar<Args...> // { dg-error "pack expansion" }
 
 int main()
 {
-  foo(1, 2, 3); // { dg-error "cannot call" }
-  bar(1, 2, 3); // { dg-error "cannot call" }
+  foo(1, 2, 3); // { dg-error "" }
+  bar(1, 2, 3); // { dg-error "" }
 }

gcc/testsuite/g++.dg/concepts/expression2.C

@@ -31,7 +31,7 @@ class S
 
 int main()
 {
-  f1(s); // { dg-error "cannot call|private" }
+  f1(s); // { dg-error "unsatisfied|private" }
   f2(s); // { dg-error "" }
 
   // When used in non-SFINAE contexts, make sure that we fail

gcc/testsuite/g++.dg/concepts/fn2.C

@@ -11,9 +11,9 @@ template<typename T>
 // Non-dependent args are checked even in dependent scope.
 template<typename T>
   void h(T x) {
-    f(0); // { dg-error "cannot call" }
+    f(0); // { dg-error "" }
   }
 
 int main() {
-  f(0); // { dg-error "cannot call" }
+  f(0); // { dg-error "" }
 }

gcc/testsuite/g++.dg/concepts/fn5.C

@@ -19,6 +19,6 @@ int main() {
   S1<char> s1;      // { dg-error "constraint|invalid" }
   S2<int, char> s2; // { dg-error "constraint|invalid" }
 
-  f('a');    // { dg-error "cannot" }
-  g(0, 'a'); // { dg-error "cannot" }
+  f('a');    // { dg-error "unsatisfied" }
+  g(0, 'a'); // { dg-error "unsatisfied" }
 }

gcc/testsuite/g++.dg/concepts/fn8.C

@@ -8,7 +8,7 @@ template<Class T> void f(T) { }
 
 template<typename T> void fn(T) { }
 
-auto p1 = &f<int>; // { dg-error "no matches" }
+auto p1 = &f<int>; // { dg-error "" }
 void (*p2)(int) = &f<int>; // { dg-error "no matches" }
 void (*p3)(int) = &f; // { dg-error "no matches" }
 
@@ -16,7 +16,7 @@ struct S {
   template<Class T> int f(T) { return 0; }
 };
 
-auto p4 = &S::template f<int>; // { dg-error "no matches" }
+auto p4 = &S::template f<int>; // { dg-error "" }
 int (S::*p6)(int) = &S::template f<int>; // { dg-error "no matches" }
 int (S::*p7)(int) = &S::f; // { dg-error "no matches" }
 

gcc/testsuite/g++.dg/concepts/placeholder5.C

@@ -14,5 +14,5 @@ concept bool C =
 template <C c>
 constexpr bool f() { return true; }
 
-static_assert(f<double>(), "");	// { dg-error "cannot call|as type" }
-static_assert(f<int>(), ""); // { dg-error "cannot call|as type" }
+static_assert(f<double>(), "");	// { dg-error "unsatisfied|as type" }
+static_assert(f<int>(), ""); // { dg-error "unsatisfied|as type" }

gcc/testsuite/g++.dg/concepts/template-parm11.C

@@ -15,5 +15,5 @@ void getTable(const ColSpec&...)
 
 void f()
 {
-  getTable(7, 'a'); // { dg-error "cannot call" }
+  getTable(7, 'a'); // { dg-error "" }
 };

gcc/testsuite/g++.dg/concepts/var-concept2.C

@@ -12,7 +12,7 @@ void f2(C1) {}
 
 int main ()
 {
-  f1(0, 0); // { dg-error "cannot call" }
-  f2(1); // { dg-error "cannot call" }
+  f1(0, 0); // { dg-error "" }
+  f2(1); // { dg-error "" }
   return 0;
 }

gcc/testsuite/g++.dg/cpp2a/concepts-dr1430.C

@@ -10,5 +10,5 @@ void foo( Args... args ) {}
 
 int main()
 {
-  foo(1, 2, 3); // { dg-error "cannot call" }
+  foo(1, 2, 3); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-fn1.C

@@ -35,7 +35,7 @@ int fn2(T t) { return 0; }
 void driver()
 {
   fn1(0); // OK
-  fn2(0); // { dg-error "cannot call function" }
+  fn2(0); // { dg-error "" }
 }
 
 // Ordering
@@ -126,7 +126,7 @@ void caller_1(T x)
 { 
   f1(x); // Unchecked dependent arg.
   f1(empty{}); // Checked non-dependent arg, but OK
-  f1(0); // { dg-error "cannot call function" }
+  f1(0); // { dg-error "" }
 }
 
 // fn3.c -- Ordering
@@ -159,7 +159,7 @@ template<typename T> requires Type<T> void ok(T) { }
 template<typename T> requires Class<T> void err(T) { }
 
 auto p1 = &ok<int>;
-auto p2 = &err<int>; // { dg-error "no matches" }
+auto p2 = &err<int>; // { dg-error "" }
 void (*p3)(int) = &ok<int>;
 void (*p4)(int) = &err<int>; // { dg-error "no matches" }
 void (*p5)(int) = &ok;
@@ -180,7 +180,7 @@ struct S2 {
 };
 
 auto p7 = &S2::ok<int>;
-auto p8 = &S2::err<int>; // { dg-error "no matches" }
+auto p8 = &S2::err<int>; // { dg-error "" }
 int (S2::*p9)(int) = &S2::ok<int>;
 int (S2::*p10)(int) = &S2::err<int>; // { dg-error "no matches" }
 int (S2::*p11)(int) = &S2::ok;

gcc/testsuite/g++.dg/cpp2a/concepts-fn3.C

@@ -31,11 +31,11 @@ struct S
 int main()
 {
   f1(1, 2, 3);
-  f1(1, 2, 3u); // { dg-error "cannot call" }
+  f1(1, 2, 3u); // { dg-error "" }
   f2(1, 2, 3);
-  f2(1, 2, 3u); // { dg-error "cannot call" }
+  f2(1, 2, 3u); // { dg-error "" }
   f3(1, 2, 3);
-  f3(1, 2, 3u); // { dg-error "cannot call" }
+  f3(1, 2, 3u); // { dg-error "" }
   f3(1u, 2, 3);
 
   S<void> s;

gcc/testsuite/g++.dg/cpp2a/concepts-fn4.C

+// Testcase from [expr.prim.id]/5
+// { dg-do compile { target c++2a } }
+
+template<typename T> struct A {
+  static void f(int) requires false;
+};
+void g() {
+  A<int>::f(0);			// { dg-error "" "cannot call f" }
+  void (*p1)(int) = A<int>::f;  // { dg-error "" "cannot take the address of f" }
+  decltype(A<int>::f)* p2 = nullptr; // { dg-error "" "the type decltype(A<int>::f) is invalid" }
+}

gcc/testsuite/g++.dg/cpp2a/concepts-friend1.C

@@ -23,7 +23,7 @@ struct X { } x;
 
 int main() {
   // f(0); // OK
-  f(nt); // { dg-error "cannot call" }
+  f(nt); // { dg-error "" }
   f(x);  // { dg-error "3:'f' was not declared" }
 
   S<int> si;

gcc/testsuite/g++.dg/cpp2a/concepts-noexcept1.C

@@ -20,6 +20,6 @@ template<C2 T>
 void g2(T t);
 
 void test() {
-  g1(0); // { dg-error "cannot call" }
+  g1(0); // { dg-error "" }
   g2(0);
 }
\ No newline at end of file

gcc/testsuite/g++.dg/cpp2a/concepts-p1141.C

@@ -79,9 +79,9 @@ void f20(Class auto x, Class auto y) { }
 
 void driver_1()
 {
-  f19(0); // { dg-error "cannot call function" }
+  f19(0); // { dg-error "" }
   f19(empty{});
-  f20(0, empty{}); // { dg-error "cannot call function" }
+  f20(0, empty{}); // { dg-error "" }
   f20(empty{}, empty{});
 }
 

gcc/testsuite/g++.dg/cpp2a/concepts-pr65575.C

@@ -19,5 +19,5 @@ int g(int (*)() requires true); // { dg-error "" }
 int
 main()
 {
-  f1(); // { dg-error "cannot call" }
+  f1(); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-pr65854.C

@@ -19,4 +19,4 @@ template<typename T1, typename T2>
   requires C<T1, T2>
 int f();
 
-auto i = f<char, int>(); // { dg-error "cannot call function" }
+auto i = f<char, int>(); // { dg-error "" }

gcc/testsuite/g++.dg/cpp2a/concepts-pr66844.C

@@ -13,4 +13,4 @@ template <typename T>
   requires C<T>
 constexpr bool is_c() { return true; }
 
-static_assert(is_c<void>(), ""); // { dg-error "cannot call" }
+static_assert(is_c<void>(), ""); // { dg-error "" }

gcc/testsuite/g++.dg/cpp2a/concepts-pr67070.C

@@ -46,6 +46,6 @@ struct X {
 };
 
 void test2() {
-  g1<X, X>(); // { dg-error "cannot call" }
-  g2<X, X>(); // { dg-error "cannot call" }
+  g1<X, X>(); // { dg-error "" }
+  g2<X, X>(); // { dg-error "" }
 }
\ No newline at end of file

gcc/testsuite/g++.dg/cpp2a/concepts-pr67178.C

@@ -20,7 +20,7 @@ template<typename T>
 void f(T) {}
 
 int main() {
-  f(1); // { dg-error "cannot call" }
+  f(1); // { dg-error "" }
 }
 
 

gcc/testsuite/g++.dg/cpp2a/concepts-pr67225-1.C

@@ -28,5 +28,5 @@ struct Y {private: ~Y();};
 
 int main()
 {
-    f<Y>(); // { dg-error "cannot call" }
+    f<Y>(); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-pr68093-1.C

@@ -9,5 +9,5 @@ struct S
 
 int main()
 {
-  foobar(S<double>{}, int{}); // { dg-error "cannot call" }
+  foobar(S<double>{}, int{}); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-requires1.C

@@ -26,7 +26,7 @@ void driver_1() {
   struct S { } s;
   f4(s);
   f5(0);
-  f5((void*)0); // { dg-error "cannot call" }
+  f5((void*)0); // { dg-error "" }
   test.f(s);
 }
 
@@ -67,5 +67,5 @@ void print2(const T& x) { }
 
 void driver_3()
 {
-  print2("hello"); // { dg-error "cannot call" }
+  print2("hello"); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-requires15.C

@@ -9,7 +9,7 @@ template<C T>
 void fun(T s) { }
 
 int main(int, char **) {
-  fun((int *)0); // { dg-error "cannot call function" }
+  fun((int *)0); // { dg-error "" }
   return 0;
 }
 

gcc/testsuite/g++.dg/cpp2a/concepts-requires16.C

@@ -37,11 +37,11 @@ void f7() { }
 
 void driver()
 {
-  f1<int, int>(); // { dg-error "cannot call function" }
+  f1<int, int>(); // { dg-error "" }
   f3<int, int>();
-  f3<int, void>(); // { dg-error "cannot call function" }
+  f3<int, void>(); // { dg-error "" }
   f4<int, int>();
-  f4<int, void>(); // { dg-error "cannot call function" }
+  f4<int, void>(); // { dg-error "" }
   f7<int>();
   f7<int, int>();
 }

gcc/testsuite/g++.dg/cpp2a/concepts-requires2.C

@@ -18,7 +18,7 @@ template<typename T> requires Bad<T> void bad(T x) { }
 
 void driver_2()
 {
-  bad(0); // { dg-error "cannot call" }
+  bad(0); // { dg-error "" }
 }
 
 // req6.C
@@ -41,8 +41,8 @@ void h2(T);
 
 void driver_3()
 {
-  h1(0); // { dg-error "cannot call" }
-  h2(0); // { dg-error "cannot call" } 
+  h1(0); // { dg-error "" }
+  h2(0); // { dg-error "" } 
 }
 
 // req7.C

gcc/testsuite/g++.dg/cpp2a/concepts-requires6.C

@@ -17,9 +17,9 @@ template <typename T>
   requires C1<T>
 constexpr bool f1() { return true; }
 
-static_assert(f1<char>()); // { dg-error "cannot call" }
-static_assert(f1<int>()); // { dg-error "cannot call" }
-static_assert(f1<double>()); // { dg-error "cannot call" }
+static_assert(f1<char>()); // { dg-error "" }
+static_assert(f1<int>()); // { dg-error "" }
+static_assert(f1<double>()); // { dg-error "" }
 
 
 template <typename T>

gcc/testsuite/g++.dg/cpp2a/concepts-requires8.C

@@ -13,5 +13,5 @@ int main()
 {
   // FIXME: This diagnostic is being emitted twice, when it should
   // be emitted just once.
-  using U = decltype(f(42, non_addable{})); // { dg-error "cannot call function" }
+  using U = decltype(f(42, non_addable{})); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-traits1.C

@@ -77,21 +77,21 @@ template<Union T> void f17() { }
 template<Enum T> void f18() { }
 
 int main() {
-  f1<void>(); // { dg-error "cannot call" }
-  f2<void>(); // { dg-error "cannot call" }
-  f3<void>(); // { dg-error "cannot call" }
-  f4<void>(); // { dg-error "cannot call" }
-  f5<void>(); // { dg-error "cannot call" }
-  f6<void>(); // { dg-error "cannot call" }
-  f7<void>(); // { dg-error "cannot call" }
-  f8<void>(); // { dg-error "cannot call" }
-  f9<void>(); // { dg-error "cannot call" }
-  f10<void>(); // { dg-error "cannot call" }
-  f11<void>(); // { dg-error "cannot call" }
-  f12<void>(); // { dg-error "cannot call" }
-  f13<void>(); // { dg-error "cannot call" }
-  f14<void>(); // { dg-error "cannot call" }
-  f15<void>(); // { dg-error "cannot call" }
-  f16<void>(); // { dg-error "cannot call" }
-  f17<void>(); // { dg-error "cannot call" }
+  f1<void>(); // { dg-error "" }
+  f2<void>(); // { dg-error "" }
+  f3<void>(); // { dg-error "" }
+  f4<void>(); // { dg-error "" }
+  f5<void>(); // { dg-error "" }
+  f6<void>(); // { dg-error "" }
+  f7<void>(); // { dg-error "" }
+  f8<void>(); // { dg-error "" }
+  f9<void>(); // { dg-error "" }
+  f10<void>(); // { dg-error "" }
+  f11<void>(); // { dg-error "" }
+  f12<void>(); // { dg-error "" }
+  f13<void>(); // { dg-error "" }
+  f14<void>(); // { dg-error "" }
+  f15<void>(); // { dg-error "" }
+  f16<void>(); // { dg-error "" }
+  f17<void>(); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-traits2.C

@@ -78,21 +78,21 @@ template<Enum T> void f18();
 
 
 int main() {
-  f1<void>(); // { dg-error "cannot call" }
-  f2<void>(); // { dg-error "cannot call" }
-  f3<void>(); // { dg-error "cannot call" }
-  f4<void>(); // { dg-error "cannot call" }
-  f5<void>(); // { dg-error "cannot call" }
-  f6<void>(); // { dg-error "cannot call" }
-  f7<void>(); // { dg-error "cannot call" }
-  f8<void>(); // { dg-error "cannot call" }
-  f9<void>(); // { dg-error "cannot call" }
-  f10<void>(); // { dg-error "cannot call" }
-  f11<void>(); // { dg-error "cannot call" }
-  f12<void>(); // { dg-error "cannot call" }
-  f13<void>(); // { dg-error "cannot call" }
-  f14<void>(); // { dg-error "cannot call" }
-  f15<void>(); // { dg-error "cannot call" }
-  f16<void>(); // { dg-error "cannot call" }
-  f17<void>(); // { dg-error "cannot call" }
+  f1<void>(); // { dg-error "" }
+  f2<void>(); // { dg-error "" }
+  f3<void>(); // { dg-error "" }
+  f4<void>(); // { dg-error "" }
+  f5<void>(); // { dg-error "" }
+  f6<void>(); // { dg-error "" }
+  f7<void>(); // { dg-error "" }
+  f8<void>(); // { dg-error "" }
+  f9<void>(); // { dg-error "" }
+  f10<void>(); // { dg-error "" }
+  f11<void>(); // { dg-error "" }
+  f12<void>(); // { dg-error "" }
+  f13<void>(); // { dg-error "" }
+  f14<void>(); // { dg-error "" }
+  f15<void>(); // { dg-error "" }
+  f16<void>(); // { dg-error "" }
+  f17<void>(); // { dg-error "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-ts1.C

@@ -35,11 +35,11 @@ auto f15(auto x) -> SameAs<decltype(x)> { return 0; } // { dg-error "deduced ret
 void driver()
 {
   f1(0);
-  f2(0); // { dg-error "cannot call" }
+  f2(0); // { dg-error "" }
   f3(0);
-  f3('a'); // { dg-error "cannot call" }
+  f3('a'); // { dg-error "" }
   f4(0, 0);
-  f4(0, 'a'); // { dg-error "cannot call" }
+  f4(0, 'a'); // { dg-error "" }
   f15(0);
   f15('a'); // { dg-message "" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts-ts2.C

@@ -38,7 +38,7 @@ int fn2(T t) { return 0; }
 void driver()
 {
   fn1(0); // OK
-  fn2(0); // { dg-error "cannot call function" }
+  fn2(0); // { dg-error "" }
 }
 
 // Ordering
@@ -129,7 +129,7 @@ void caller_1(T x)
 { 
   f1(x); // Unchecked dependent arg.
   f1(empty{}); // Checked non-dependent arg, but OK
-  f1(0); // { dg-error "cannot call function" }
+  f1(0); // { dg-error "" }
 }
 
 // fn3.c -- Ordering
@@ -162,7 +162,7 @@ template<typename T> requires (Type<T>()) void ok(T) { }
 template<typename T> requires (Class<T>()) void err(T) { }
 
 auto p1 = &ok<int>;
-auto p2 = &err<int>; // { dg-error "no matches" }
+auto p2 = &err<int>; // { dg-error "" }
 void (*p3)(int) = &ok<int>;
 void (*p4)(int) = &err<int>; // { dg-error "no matches" }
 void (*p5)(int) = &ok;
@@ -183,7 +183,7 @@ struct S2 {
 };
 
 auto p7 = &S2::ok<int>;
-auto p8 = &S2::err<int>; // { dg-error "no matches" }
+auto p8 = &S2::err<int>; // { dg-error "" }
 int (S2::*p9)(int) = &S2::ok<int>;
 int (S2::*p10)(int) = &S2::err<int>; // { dg-error "no matches" }
 int (S2::*p11)(int) = &S2::ok;

gcc/testsuite/g++.dg/cpp2a/concepts-ts3.C

@@ -38,7 +38,7 @@ int fn2(T t) { return 0; }
 void driver()
 {
   fn1(0); // OK
-  fn2(0); // { dg-error "cannot call function" }
+  fn2(0); // { dg-error "" }
 }
 
 // Ordering
@@ -129,7 +129,7 @@ void caller_1(T x)
 { 
   f1(x); // Unchecked dependent arg.
   f1(empty{}); // Checked non-dependent arg, but OK
-  f1(0); // { dg-error "cannot call function" }
+  f1(0); // { dg-error "" }
 }
 
 // fn3.c -- Ordering
@@ -162,7 +162,7 @@ template<typename T> requires Type<T> void ok(T) { }
 template<typename T> requires Class<T> void err(T) { }
 
 auto p1 = &ok<int>;
-auto p2 = &err<int>; // { dg-error "no matches" }
+auto p2 = &err<int>; // { dg-error "" }
 void (*p3)(int) = &ok<int>;
 void (*p4)(int) = &err<int>; // { dg-error "no matches" }
 void (*p5)(int) = &ok;
@@ -183,7 +183,7 @@ struct S2 {
 };
 
 auto p7 = &S2::ok<int>;
-auto p8 = &S2::err<int>; // { dg-error "no matches" }
+auto p8 = &S2::err<int>; // { dg-error "" }
 int (S2::*p9)(int) = &S2::ok<int>;
 int (S2::*p10)(int) = &S2::err<int>; // { dg-error "no matches" }
 int (S2::*p11)(int) = &S2::ok;

gcc/testsuite/g++.dg/cpp2a/concepts-ts4.C

@@ -23,12 +23,12 @@ Pos{N} void fn();
 void driver()
 {
   f1(0);
-  f2(0); // { dg-error "cannot call function" }
+  f2(0); // { dg-error "" }
 
   same<int, int>();
-  same<int, char>(); // { dg-error "cannot call function" }
+  same<int, char>(); // { dg-error "" }
 
   fn<0>(); // OK
-  fn<-1>(); // { dg-error "cannot call function" }
+  fn<-1>(); // { dg-error "" }
   fn<int>(); // { dg-error "no matching function" }
 }

gcc/testsuite/g++.dg/cpp2a/concepts1.C

@@ -19,7 +19,7 @@ void decl1(T);
 
 void driver_1()
 {
-  f1(0); // { dg-error "cannot call function" }
+  f1(0); // { dg-error "" }
   f1(empty{});
 
   decl1(empty{}); // { dg-error "call of overload | ambiguous" }

gcc/testsuite/g++.dg/cpp2a/concepts3.C

@@ -42,7 +42,7 @@ template<typename T>
 void f3() { }
 
 void driver2() {
-  f1<S1>(); // { dg-error "cannot call|is private" }
-  f2<S1>(); // { dg-error "cannot call|is private" }
-  f3<S1>(); // { dg-error "cannot call|is private" }
+  f1<S1>(); // { dg-error "unsatisfied|is private" }
+  f2<S1>(); // { dg-error "unsatisfied|is private" }
+  f3<S1>(); // { dg-error "unsatisfied|is private" }
 }