[committed] libstdc++: Deprecate std::setfill for std::basic_istream [PR109922]

[committed] libstdc++: Deprecate std::setfill for std::basic_istream [PR109922]

[Jonathan Wakely]

Tested powerpc64le-linux. Pushed to trunk.

-- >8 --

Prior to N0966 (July 1996) the std::setfill manipulator was specified to
work with both input and output streams. In the final C++98 standard it
is only specified to work with output streams.

We have always supported it for input streams, despite that never being
in the standard, and having no meaning for any input streams defined by
the standard. This commit adds a deprecated attribute to the overload
for input streams, so that we can stop supporting this some day.

libstdc++-v3/ChangeLog:

	PR libstdc++/109922
	* include/std/iomanip (operator>>(basic_istream&, _Setfill)):
	Add deprecated attribute to non-standard overload.
	* doc/xml/manual/evolution.xml: Document deprecation.
	* doc/html/*: Regenerate.
	* testsuite/27_io/manipulators/standard/char/1.cc: Add
	dg-warning for expected deprecated warning.
	* testsuite/27_io/manipulators/standard/char/2.cc: Likewise.
	* testsuite/27_io/manipulators/standard/wchar_t/1.cc: Likewise.
	* testsuite/27_io/manipulators/standard/wchar_t/2.cc: Likewise.
---
 libstdc++-v3/doc/html/index.html                         | 2 +-
 libstdc++-v3/doc/html/manual/api.html                    | 3 +++
 libstdc++-v3/doc/html/manual/appendix.html               | 2 +-
 libstdc++-v3/doc/html/manual/appendix_porting.html       | 2 +-
 libstdc++-v3/doc/html/manual/index.html                  | 2 +-
 libstdc++-v3/doc/xml/manual/evolution.xml                | 9 +++++++++
 libstdc++-v3/include/std/iomanip                         | 2 ++
 .../testsuite/27_io/manipulators/standard/char/1.cc      | 4 ++--
 .../testsuite/27_io/manipulators/standard/char/2.cc      | 2 +-
 .../testsuite/27_io/manipulators/standard/wchar_t/1.cc   | 4 ++--
 .../testsuite/27_io/manipulators/standard/wchar_t/2.cc   | 2 +-
 11 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/libstdc++-v3/doc/xml/manual/evolution.xml b/libstdc++-v3/doc/xml/manual/evolution.xml
index a29e4df3822..4037a18d2df 100644
--- a/libstdc++-v3/doc/xml/manual/evolution.xml
+++ b/libstdc++-v3/doc/xml/manual/evolution.xml
@@ -1089,4 +1089,13 @@ Tunables <variable>glibcxx.eh_pool.obj_count</variable> and
 
 </section>
 
+<section xml:id="api.rel_141"><info><title><constant>14</constant></title></info>
+
+<para>
+Deprecate the non-standard overload that allows <code>std::setfill</code>
+to be used with <code>std::basic_istream</code>.
+</para>
+
+</section>
+
 </section>
diff --git a/libstdc++-v3/include/std/iomanip b/libstdc++-v3/include/std/iomanip
index 5c0fb09a60e..eb82fc584b6 100644
--- a/libstdc++-v3/include/std/iomanip
+++ b/libstdc++-v3/include/std/iomanip
@@ -168,6 +168,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     { return { __c }; }
 
   template<typename _CharT, typename _Traits>
+    __attribute__((__deprecated__("'std::setfill' should only be used with "
+				  "output streams")))
     inline basic_istream<_CharT, _Traits>&
     operator>>(basic_istream<_CharT, _Traits>& __is, _Setfill<_CharT> __f)
     {
diff --git a/libstdc++-v3/testsuite/27_io/manipulators/standard/char/1.cc b/libstdc++-v3/testsuite/27_io/manipulators/standard/char/1.cc
index d3eba45aac1..4da43200fe5 100644
--- a/libstdc++-v3/testsuite/27_io/manipulators/standard/char/1.cc
+++ b/libstdc++-v3/testsuite/27_io/manipulators/standard/char/1.cc
@@ -51,9 +51,9 @@ test01()
   oss << setbase(8);
   VERIFY(oss.good());
 
-  // setfil
+  // setfill
   setfill('a');
-  iss >> setfill('a');
+  iss >> setfill('a'); // { dg-warning "deprecated" }
   VERIFY(iss.good());
   oss << setfill('a');
   VERIFY(oss.good());
diff --git a/libstdc++-v3/testsuite/27_io/manipulators/standard/char/2.cc b/libstdc++-v3/testsuite/27_io/manipulators/standard/char/2.cc
index dc74e1983c7..9acc057ccbb 100644
--- a/libstdc++-v3/testsuite/27_io/manipulators/standard/char/2.cc
+++ b/libstdc++-v3/testsuite/27_io/manipulators/standard/char/2.cc
@@ -40,7 +40,7 @@ test01()
   sin >> resetiosflags(ios_base::dec)
       >> setiosflags(ios_base::dec)
       >> setbase(ios_base::dec)
-      >> setfill('c')
+      >> setfill('c') // { dg-warning "deprecated" }
       >> setprecision(5)
       >> setw(20)
       >> ws;
diff --git a/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/1.cc b/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/1.cc
index 0c27e8b126a..ebfab0cc732 100644
--- a/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/1.cc
+++ b/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/1.cc
@@ -51,9 +51,9 @@ test01()
   oss << setbase(8);
   VERIFY(oss.good());
 
-  // setfil
+  // setfill
   setfill(L'a');
-  iss >> setfill(L'a');
+  iss >> setfill(L'a'); // { dg-warning "deprecated" }
   VERIFY(iss.good());
   oss << setfill(L'a');
   VERIFY(oss.good());
diff --git a/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/2.cc b/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/2.cc
index 509c152a6d7..78b812d4288 100644
--- a/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/2.cc
+++ b/libstdc++-v3/testsuite/27_io/manipulators/standard/wchar_t/2.cc
@@ -40,7 +40,7 @@ test01()
   sin >> resetiosflags(ios_base::dec)
       >> setiosflags(ios_base::dec)
       >> setbase(ios_base::dec)
-      >> setfill(L'c')
+      >> setfill(L'c') // { dg-warning "deprecated" }
       >> setprecision(5)
       >> setw(20)
       >> ws;
-- 
2.40.1