PR c++/90243 - orphaned note in uninstantiated constexpr function

gcc/cp:

	PR c++/90243 - orphaned note in uninstantiated constexpr function
	* decl.c (check_for_uninitialized_const_var): Suppress notes if no
	error was shown.

gcc/testsuite:

	PR c++/90243
	* g++.dg/diagnostic/pr90243.C: New test.

From-SVN: r270610

gcc/cp/ChangeLog

+2019-04-26  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR c++/90243 - orphaned note in uninstantiated constexpr function
+	* decl.c (check_for_uninitialized_const_var): Suppress notes if no
+	error was shown.
+
 2019-04-26  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/90173

gcc/cp/decl.c

@@ -5691,13 +5691,15 @@ check_for_uninitialized_const_var (tree decl, bool constexpr_context_p,
       if (!field)
 	return true;
 
+      bool show_notes = true;
+
       if (!constexpr_context_p)
 	{
 	  if (CP_TYPE_CONST_P (type))
 	    {
 	      if (complain & tf_error)
-		permerror (DECL_SOURCE_LOCATION (decl),
-			   "uninitialized const %qD", decl);
+		show_notes = permerror (DECL_SOURCE_LOCATION (decl),
+				        "uninitialized const %qD", decl);
 	    }
 	  else
 	    {
@@ -5706,6 +5708,8 @@ check_for_uninitialized_const_var (tree decl, bool constexpr_context_p,
 		error_at (DECL_SOURCE_LOCATION (decl),
 			  "uninitialized variable %qD in %<constexpr%> "
 			  "function", decl);
+	      else
+		show_notes = false;
 	      cp_function_chain->invalid_constexpr = true;
 	    }
 	}
@@ -5714,7 +5718,7 @@ check_for_uninitialized_const_var (tree decl, bool constexpr_context_p,
 		  "uninitialized variable %qD in %<constexpr%> context",
 		  decl);
 
-      if (CLASS_TYPE_P (type) && (complain & tf_error))
+      if (show_notes && CLASS_TYPE_P (type) && (complain & tf_error))
 	{
 	  tree defaulted_ctor;
 

gcc/testsuite/ChangeLog

+2019-04-26  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR c++/90243
+	* g++.dg/diagnostic/pr90243.C: New test.
+
 2019-04-26  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/90173

gcc/testsuite/g++.dg/diagnostic/pr90243.C

+// { dg-do compile { target c++14 } }
+struct Z { // { dg-bogus "default constructor" }
+  int y;   // { dg-bogus "initialize" }
+};
+
+template <class T>
+constexpr Z f(const T *data) {
+  Z z;
+  __builtin_memcpy(&z, data, sizeof(z));
+  return z;
+}
+
+constexpr Z g(const char *data) { return f(data); }