From: Jonathan Wakely <jwakely@redhat.com>
Date: Wed, 19 Aug 2020 11:13:03 +0000 (+0100)
Subject: libstdc++: Add deprecated attributes to old iostream members
X-Git-Tag: releases/gcc-9.4.0~748
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=495bdda5305b366e6f15134431d9d18b952884fc;p=thirdparty%2Fgcc.git

libstdc++: Add deprecated attributes to old iostream members

Back in 2017 I removed these prehistoric members (which were deprecated
since C++98) for C++17 mode. But I didn't add deprecated attributes to
most of them, so users didn't get any warning they would be going away.
Apparently some poor souls do actually use some of these names, and so
now that GCC 11 defaults to -std=gnu++17 some code has stopped
compiling.

This adds deprecated attributes to them, so that C++98/03/11/14 code
will get a warning if it uses them. I'll also backport this to the
release branches so that users can find out about the deprecation before
they start using C++17.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_DEPRECATED_SUGGEST): New
	macro for "use 'foo' instead" message in deprecated warnings.
	* include/bits/ios_base.h (io_state, open_mode, seek_dir)
	(streampos, streamoff): Use _GLIBCXX_DEPRECATED_SUGGEST.
	* include/std/streambuf (stossc): Replace C++11 attribute
	with _GLIBCXX_DEPRECATED_SUGGEST.
	* testsuite/27_io/types/1.cc: Check for deprecated warnings.
	Also check for io_state, open_mode and seek_dir typedefs.

(cherry picked from commit eef9bf4ca8d90a1751bc4bff03722ee68999eb8e)
---

diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config
index 7e0962edd199..d2c2efe1c06f 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -77,6 +77,7 @@
 // Macros for deprecated attributes.
 //   _GLIBCXX_USE_DEPRECATED
 //   _GLIBCXX_DEPRECATED
+//   _GLIBCXX_DEPRECATED_SUGGEST
 //   _GLIBCXX17_DEPRECATED
 #ifndef _GLIBCXX_USE_DEPRECATED
 # define _GLIBCXX_USE_DEPRECATED 1
@@ -84,8 +85,11 @@
 
 #if defined(__DEPRECATED) && (__cplusplus >= 201103L)
 # define _GLIBCXX_DEPRECATED __attribute__ ((__deprecated__))
+# define _GLIBCXX_DEPRECATED_SUGGEST(ALT) \
+  __attribute__ ((__deprecated__ ("use '" ALT "' instead")))
 #else
 # define _GLIBCXX_DEPRECATED
+# define _GLIBCXX_DEPRECATED_SUGGEST(ALT)
 #endif
 
 #if defined(__DEPRECATED) && (__cplusplus >= 201703L)
diff --git a/libstdc++-v3/include/bits/ios_base.h b/libstdc++-v3/include/bits/ios_base.h
index be908b3ffd27..bc96ff6ddc86 100644
--- a/libstdc++-v3/include/bits/ios_base.h
+++ b/libstdc++-v3/include/bits/ios_base.h
@@ -471,12 +471,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 #if __cplusplus <= 201402L
     // Annex D.6 (removed in C++17)
-    typedef int io_state;
-    typedef int open_mode;
-    typedef int seek_dir;
-
-    typedef std::streampos streampos;
-    typedef std::streamoff streamoff;
+    typedef int io_state
+      _GLIBCXX_DEPRECATED_SUGGEST("std::iostate");
+    typedef int open_mode
+      _GLIBCXX_DEPRECATED_SUGGEST("std::openmode");
+    typedef int seek_dir
+      _GLIBCXX_DEPRECATED_SUGGEST("std::seekdir");
+
+    typedef std::streampos streampos
+      _GLIBCXX_DEPRECATED_SUGGEST("std::streampos");
+    typedef std::streamoff streamoff
+      _GLIBCXX_DEPRECATED_SUGGEST("std::streamoff");
 #endif
 
     // Callbacks;
diff --git a/libstdc++-v3/include/std/streambuf b/libstdc++-v3/include/std/streambuf
index d9ca981d7047..f812e32de42f 100644
--- a/libstdc++-v3/include/std/streambuf
+++ b/libstdc++-v3/include/std/streambuf
@@ -786,9 +786,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        *
        *  See http://gcc.gnu.org/ml/libstdc++/2002-05/msg00168.html
        */
-#if __cplusplus >= 201103L
-      [[__deprecated__("stossc is deprecated, use sbumpc instead")]]
-#endif
+      _GLIBCXX_DEPRECATED_SUGGEST("std::basic_streambuf::sbumpc")
       void
       stossc()
       {
diff --git a/libstdc++-v3/testsuite/27_io/types/1.cc b/libstdc++-v3/testsuite/27_io/types/1.cc
index 640ff7373308..19a42360b11d 100644
--- a/libstdc++-v3/testsuite/27_io/types/1.cc
+++ b/libstdc++-v3/testsuite/27_io/types/1.cc
@@ -15,6 +15,7 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
+// { dg-options "-Wdeprecated" }
 // { dg-do compile { target c++14_down } }
 
 // 27.4.2.1 - Types [lib.ios.types]
@@ -26,6 +27,14 @@
 // Annex D, deprecated.
 void test01()
 {
-  typedef std::ios_base::streampos streampos_type;
-  typedef std::ios_base::streamoff streamoff_type;
+  typedef std::ios_base::streampos streampos_type; // { dg-warning "is deprecated: use 'std::streampos' instead" }
+  typedef std::ios_base::streamoff streamoff_type; // { dg-warning "is deprecated: use 'std::streamoff' instead" }
+}
+
+// Annex D, deprecated.
+void test02()
+{
+  typedef std::ios_base::io_state iostate_type; // { dg-warning "is deprecated: use 'std::iostate' instead" }
+  typedef std::ios_base::open_mode openmode_type; // { dg-warning "is deprecated: use 'std::openmode' instead" }
+  typedef std::ios_base::seek_dir seekdir_type; // { dg-warning "is deprecated: use 'std::seekdir' instead" }
 }