c++: Fix thinko in auto return type checking [PR98441]
authorMarek Polacek <polacek@redhat.com>
Wed, 6 Jan 2021 00:17:10 +0000 (19:17 -0500)
committerMarek Polacek <polacek@redhat.com>
Thu, 7 Jan 2021 21:19:29 +0000 (16:19 -0500)
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.

gcc/cp/decl.c
gcc/testsuite/g++.dg/cpp0x/auto55.C [new file with mode: 0644]

index bf6f12c26a006a3b8f3403c2fe2ae15560f46ce3..1a114a2e2d095725bf1a3624279550dd08722613 100644 (file)
@@ -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 (file)
index 0000000..5bd32ac
--- /dev/null
@@ -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;
+}