From: Marek Polacek <polacek@redhat.com>
Date: Wed, 6 Jan 2021 00:17:10 +0000 (-0500)
Subject: c++: Fix thinko in auto return type checking [PR98441]
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2f359597e49a15a2aef8f83ea7a14649854334cb;p=gcc.git

c++: Fix thinko in auto return type checking [PR98441]

This fixes a thinko in my r11-2085 patch: when I said "But only give the
!late_return_type errors when funcdecl_p, to accept e.g. auto (*fp)() = f;
in C++11" I should've done this, otherwise we give bogus errors mentioning
"function with trailing return type" when there is none.

gcc/cp/ChangeLog:

	PR c++/98441
	* decl.c (grokdeclarator): Move the !funcdecl_p check inside the
	!late_return_type block.

gcc/testsuite/ChangeLog:

	PR c++/98441
	* g++.dg/cpp0x/auto55.C: New test.
---

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index bf6f12c26a0..1a114a2e2d0 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -12241,10 +12241,12 @@ grokdeclarator (const cp_declarator *declarator,
 	    tree late_return_type = declarator->u.function.late_return_type;
 	    if (tree auto_node = type_uses_auto (type))
 	      {
-		if (!late_return_type && funcdecl_p)
+		if (!late_return_type)
 		  {
-		    if (current_class_type
-			&& LAMBDA_TYPE_P (current_class_type))
+		    if (!funcdecl_p)
+		      /* auto (*fp)() = f; is OK.  */;
+		    else if (current_class_type
+			     && LAMBDA_TYPE_P (current_class_type))
 		      /* OK for C++11 lambdas.  */;
 		    else if (cxx_dialect < cxx14)
 		      {
diff --git a/gcc/testsuite/g++.dg/cpp0x/auto55.C b/gcc/testsuite/g++.dg/cpp0x/auto55.C
new file mode 100644
index 00000000000..5bd32ac890d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/auto55.C
@@ -0,0 +1,13 @@
+// PR c++/98441
+// { dg-do compile { target c++11 } }
+
+struct a {
+    int& mfn();
+};
+
+void fn()
+{
+    int&  (a::*myvar1)(void) = &a::mfn;
+    auto& (a::*myvar2)(void) = &a::mfn;
+    auto  (a::*myvar3)(void) = &a::mfn;
+}