diff mbox series

libstdc++: Deprecate useless <cxxx> compatibility headers for C++17

Message ID 20241031201052.1628008-1-jwakely@redhat.com
State New
Headers show
Series libstdc++: Deprecate useless <cxxx> compatibility headers for C++17 | expand

Commit Message

Jonathan Wakely Oct. 31, 2024, 8:09 p.m. UTC
Tested x86_64-linux. Is the g++ test change OK?

Also available for review at:
https://forge.sourceware.org/gcc/gcc-TEST/pulls/4

-- >8 --

These headers make no sense for C++ programs, because they either define
different content to the corresponding <xxx.h> C header, or define
nothing at all in namespace std. They were all deprecated in C++17, so
add deprecation warnings to them, which can be disabled with
-Wno-deprecated. For C++20 and later these headers are no longer in the
standard at all, so compiling with _GLIBCXX_USE_DEPRECATED defined to 0
will give an error when they are included.

Because #warning is non-standard before C++23 we need to use pragmas to
ignore -Wc++23-extensions for the -Wsystem-headers -pedantic case.

One g++ test needs adjustment because it includes <ciso646>, but that
can be made conditional on the __cplusplus value without any reduction
in test coverage.

For the library tests, consolidate the std_c++0x_neg.cc XFAIL tests into
the macros.cc test, using dg-error with a { target c++98_only }
selector. This avoids having two separate test files, one for C++98 and
one for everything later. Also add tests for the <xxx.h> headers to
ensure that they behave as expected and don't give deprecated warnings.

libstdc++-v3/ChangeLog:

	* doc/xml/manual/evolution.xml: Document deprecations.
	* doc/html/*: Regenerate.
	* include/c_compatibility/complex.h (_GLIBCXX_COMPLEX_H): Move
	include guard to start of file. Include <complex> directly
	instead of <ccomplex>.
	* include/c_compatibility/tgmath.h: Include <cmath> and
	<complex> directly, instead of <ctgmath>.
	* include/c_global/ccomplex: Add deprecated #warning for C++17
	and #error for C++20 if _GLIBCXX_USE_DEPRECATED == 0.
	* include/c_global/ciso646: Likewise.
	* include/c_global/cstdalign: Likewise.
	* include/c_global/cstdbool: Likewise.
	* include/c_global/ctgmath: Likewise.
	* include/c_std/ciso646: Likewise.
	* include/precompiled/stdc++.h: Do not include ccomplex,
	ciso646, cstdalign, cstdbool, or ctgmath in C++17 and later.
	* testsuite/18_support/headers/cstdalign/macros.cc: Check for
	warnings and errors for unsupported dialects.
	* testsuite/18_support/headers/cstdbool/macros.cc: Likewise.
	* testsuite/26_numerics/headers/ctgmath/complex.cc: Likewise.
	* testsuite/27_io/objects/char/1.cc: Do not include <ciso646>.
	* testsuite/27_io/objects/wchar_t/1.cc: Likewise.
	* testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc: Removed.
	* testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc: Removed.
	* testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc: Removed.
	* testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc: Removed.
	* testsuite/18_support/headers/ciso646/macros.cc: New test.
	* testsuite/18_support/headers/ciso646/macros.h.cc: New test.
	* testsuite/18_support/headers/cstdbool/macros.h.cc: New test.
	* testsuite/26_numerics/headers/ccomplex/complex.cc: New test.
	* testsuite/26_numerics/headers/ccomplex/complex.h.cc: New test.
	* testsuite/26_numerics/headers/ctgmath/complex.h.cc: New test.

gcc/testsuite/ChangeLog:

	* g++.old-deja/g++.other/headers1.C: Do not include ciso646 for
	C++17 and later.
---
 .../g++.old-deja/g++.other/headers1.C         |  2 +
 libstdc++-v3/doc/html/manual/api.html         |  8 +++
 libstdc++-v3/doc/xml/manual/evolution.xml     | 10 ++++
 .../include/c_compatibility/complex.h         | 10 ++--
 libstdc++-v3/include/c_compatibility/tgmath.h | 11 ++--
 libstdc++-v3/include/c_global/ccomplex        |  9 ++++
 libstdc++-v3/include/c_global/ciso646         |  9 ++++
 libstdc++-v3/include/c_global/cstdalign       |  8 +++
 libstdc++-v3/include/c_global/cstdbool        |  8 +++
 libstdc++-v3/include/c_global/ctgmath         | 14 +++--
 libstdc++-v3/include/c_std/ciso646            | 10 ++++
 libstdc++-v3/include/precompiled/stdc++.h     | 13 +++--
 .../18_support/headers/ciso646/macros.cc      | 51 +++++++++++++++++++
 .../18_support/headers/ciso646/macros.h.cc    | 49 ++++++++++++++++++
 .../18_support/headers/cstdalign/macros.cc    | 10 +++-
 .../18_support/headers/cstdalign/macros.h.cc  | 25 +++++++++
 .../headers/cstdalign/std_c++0x_neg.cc        | 24 ---------
 .../18_support/headers/cstdbool/macros.cc     |  9 +++-
 .../18_support/headers/cstdbool/macros.h.cc   | 21 ++++++++
 .../headers/cstdbool/std_c++0x_neg.cc         | 26 ----------
 .../26_numerics/headers/ccomplex/complex.cc   | 10 ++++
 .../26_numerics/headers/ccomplex/complex.h.cc | 10 ++++
 .../headers/ccomplex/std_c++0x_neg.cc         | 26 ----------
 .../26_numerics/headers/ctgmath/complex.cc    |  9 +++-
 .../26_numerics/headers/ctgmath/complex.h.cc  | 10 ++++
 .../headers/ctgmath/std_c++0x_neg.cc          | 26 ----------
 .../testsuite/27_io/objects/char/1.cc         |  1 -
 .../testsuite/27_io/objects/wchar_t/1.cc      |  1 -
 28 files changed, 294 insertions(+), 126 deletions(-)
 create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
 create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
 create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
 delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
 create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
 delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
 create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
 create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
 delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
 create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
 delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc

Comments

Jason Merrill Nov. 1, 2024, 3:41 p.m. UTC | #1
On 10/31/24 4:09 PM, Jonathan Wakely wrote:
> Tested x86_64-linux. Is the g++ test change OK?

Yes.

> Also available for review at:
> https://forge.sourceware.org/gcc/gcc-TEST/pulls/4
> 
> -- >8 --
> 
> These headers make no sense for C++ programs, because they either define
> different content to the corresponding <xxx.h> C header, or define
> nothing at all in namespace std. They were all deprecated in C++17, so
> add deprecation warnings to them, which can be disabled with
> -Wno-deprecated. For C++20 and later these headers are no longer in the
> standard at all, so compiling with _GLIBCXX_USE_DEPRECATED defined to 0
> will give an error when they are included.
> 
> Because #warning is non-standard before C++23 we need to use pragmas to
> ignore -Wc++23-extensions for the -Wsystem-headers -pedantic case.
> 
> One g++ test needs adjustment because it includes <ciso646>, but that
> can be made conditional on the __cplusplus value without any reduction
> in test coverage.
> 
> For the library tests, consolidate the std_c++0x_neg.cc XFAIL tests into
> the macros.cc test, using dg-error with a { target c++98_only }
> selector. This avoids having two separate test files, one for C++98 and
> one for everything later. Also add tests for the <xxx.h> headers to
> ensure that they behave as expected and don't give deprecated warnings.
> 
> libstdc++-v3/ChangeLog:
> 
> 	* doc/xml/manual/evolution.xml: Document deprecations.
> 	* doc/html/*: Regenerate.
> 	* include/c_compatibility/complex.h (_GLIBCXX_COMPLEX_H): Move
> 	include guard to start of file. Include <complex> directly
> 	instead of <ccomplex>.
> 	* include/c_compatibility/tgmath.h: Include <cmath> and
> 	<complex> directly, instead of <ctgmath>.
> 	* include/c_global/ccomplex: Add deprecated #warning for C++17
> 	and #error for C++20 if _GLIBCXX_USE_DEPRECATED == 0.
> 	* include/c_global/ciso646: Likewise.
> 	* include/c_global/cstdalign: Likewise.
> 	* include/c_global/cstdbool: Likewise.
> 	* include/c_global/ctgmath: Likewise.
> 	* include/c_std/ciso646: Likewise.
> 	* include/precompiled/stdc++.h: Do not include ccomplex,
> 	ciso646, cstdalign, cstdbool, or ctgmath in C++17 and later.
> 	* testsuite/18_support/headers/cstdalign/macros.cc: Check for
> 	warnings and errors for unsupported dialects.
> 	* testsuite/18_support/headers/cstdbool/macros.cc: Likewise.
> 	* testsuite/26_numerics/headers/ctgmath/complex.cc: Likewise.
> 	* testsuite/27_io/objects/char/1.cc: Do not include <ciso646>.
> 	* testsuite/27_io/objects/wchar_t/1.cc: Likewise.
> 	* testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc: Removed.
> 	* testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc: Removed.
> 	* testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc: Removed.
> 	* testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc: Removed.
> 	* testsuite/18_support/headers/ciso646/macros.cc: New test.
> 	* testsuite/18_support/headers/ciso646/macros.h.cc: New test.
> 	* testsuite/18_support/headers/cstdbool/macros.h.cc: New test.
> 	* testsuite/26_numerics/headers/ccomplex/complex.cc: New test.
> 	* testsuite/26_numerics/headers/ccomplex/complex.h.cc: New test.
> 	* testsuite/26_numerics/headers/ctgmath/complex.h.cc: New test.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.old-deja/g++.other/headers1.C: Do not include ciso646 for
> 	C++17 and later.
> ---
>   .../g++.old-deja/g++.other/headers1.C         |  2 +
>   libstdc++-v3/doc/html/manual/api.html         |  8 +++
>   libstdc++-v3/doc/xml/manual/evolution.xml     | 10 ++++
>   .../include/c_compatibility/complex.h         | 10 ++--
>   libstdc++-v3/include/c_compatibility/tgmath.h | 11 ++--
>   libstdc++-v3/include/c_global/ccomplex        |  9 ++++
>   libstdc++-v3/include/c_global/ciso646         |  9 ++++
>   libstdc++-v3/include/c_global/cstdalign       |  8 +++
>   libstdc++-v3/include/c_global/cstdbool        |  8 +++
>   libstdc++-v3/include/c_global/ctgmath         | 14 +++--
>   libstdc++-v3/include/c_std/ciso646            | 10 ++++
>   libstdc++-v3/include/precompiled/stdc++.h     | 13 +++--
>   .../18_support/headers/ciso646/macros.cc      | 51 +++++++++++++++++++
>   .../18_support/headers/ciso646/macros.h.cc    | 49 ++++++++++++++++++
>   .../18_support/headers/cstdalign/macros.cc    | 10 +++-
>   .../18_support/headers/cstdalign/macros.h.cc  | 25 +++++++++
>   .../headers/cstdalign/std_c++0x_neg.cc        | 24 ---------
>   .../18_support/headers/cstdbool/macros.cc     |  9 +++-
>   .../18_support/headers/cstdbool/macros.h.cc   | 21 ++++++++
>   .../headers/cstdbool/std_c++0x_neg.cc         | 26 ----------
>   .../26_numerics/headers/ccomplex/complex.cc   | 10 ++++
>   .../26_numerics/headers/ccomplex/complex.h.cc | 10 ++++
>   .../headers/ccomplex/std_c++0x_neg.cc         | 26 ----------
>   .../26_numerics/headers/ctgmath/complex.cc    |  9 +++-
>   .../26_numerics/headers/ctgmath/complex.h.cc  | 10 ++++
>   .../headers/ctgmath/std_c++0x_neg.cc          | 26 ----------
>   .../testsuite/27_io/objects/char/1.cc         |  1 -
>   .../testsuite/27_io/objects/wchar_t/1.cc      |  1 -
>   28 files changed, 294 insertions(+), 126 deletions(-)
>   create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
>   create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
>   create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
>   delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
>   create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
>   delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
>   create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
>   create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
>   delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
>   create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
>   delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
> 
> diff --git a/gcc/testsuite/g++.old-deja/g++.other/headers1.C b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
> index 5d37e94082f..90a1a7dc8f9 100644
> --- a/gcc/testsuite/g++.old-deja/g++.other/headers1.C
> +++ b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
> @@ -12,7 +12,9 @@
>   #include <cctype>
>   #include <cerrno>
>   #include <cfloat>
> +#if __cplusplus < 201703L
>   #include <ciso646>
> +#endif
>   #include <climits>
>   #include <clocale>
>   #include <cmath>
> diff --git a/libstdc++-v3/doc/html/manual/api.html b/libstdc++-v3/doc/html/manual/api.html
> index 799f6eae2a2..2ccfc07b83e 100644
> --- a/libstdc++-v3/doc/html/manual/api.html
> +++ b/libstdc++-v3/doc/html/manual/api.html
> @@ -498,4 +498,12 @@ to be used with <code class="code">std::basic_istream</code>.
>     longer allowed in C++20 mode.
>   </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_151"></a><code class="constant">15</code></h3></div></div></div><p>
>   Enabled debug assertions by default for unoptimized builds.
> +</p><p>
> +Added warnings when including the headers that were deprecated in C++17
> +and removed in C++20:
> +<code class="filename">&lt;ccomplex&gt;</code>,
> +<code class="filename">&lt;ciso646&gt;</code>,
> +<code class="filename">&lt;cstdalign&gt;</code>,
> +<code class="filename">&lt;cstdbool&gt;</code>, and
> +<code class="filename">&lt;ctgmath&gt;</code>.
>   </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="abi.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="appendix_porting.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="backwards.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ABI Policy and Guidelines </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Backwards Compatibility</td></tr></table></div></body></html>
> \ No newline at end of file
> diff --git a/libstdc++-v3/doc/xml/manual/evolution.xml b/libstdc++-v3/doc/xml/manual/evolution.xml
> index 75cf948a4a2..6b134de0e71 100644
> --- a/libstdc++-v3/doc/xml/manual/evolution.xml
> +++ b/libstdc++-v3/doc/xml/manual/evolution.xml
> @@ -1135,6 +1135,16 @@ to be used with <code>std::basic_istream</code>.
>   Enabled debug assertions by default for unoptimized builds.
>   </para>
>   
> +<para>
> +Added warnings when including the headers that were deprecated in C++17
> +and removed in C++20:
> +<filename class="headerfile">&lt;ccomplex&gt;</filename>,
> +<filename class="headerfile">&lt;ciso646&gt;</filename>,
> +<filename class="headerfile">&lt;cstdalign&gt;</filename>,
> +<filename class="headerfile">&lt;cstdbool&gt;</filename>, and
> +<filename class="headerfile">&lt;ctgmath&gt;</filename>.
> +</para>
> +
>   </section>
>   
>   </section>
> diff --git a/libstdc++-v3/include/c_compatibility/complex.h b/libstdc++-v3/include/c_compatibility/complex.h
> index 605d1f30e06..461ff2117b1 100644
> --- a/libstdc++-v3/include/c_compatibility/complex.h
> +++ b/libstdc++-v3/include/c_compatibility/complex.h
> @@ -26,10 +26,15 @@
>    *  This is a Standard C++ Library header.
>    */
>   
> +#ifndef _GLIBCXX_COMPLEX_H
> +#define _GLIBCXX_COMPLEX_H 1
> +
>   #include <bits/c++config.h>
>   
>   #if __cplusplus >= 201103L
> -# include <ccomplex>
> +extern "C++" {
> +#include <complex>
> +}
>   #endif
>   
>   #if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
> @@ -42,7 +47,4 @@
>   # endif
>   #endif
>   
> -#ifndef _GLIBCXX_COMPLEX_H
> -#define _GLIBCXX_COMPLEX_H 1
> -
>   #endif
> diff --git a/libstdc++-v3/include/c_compatibility/tgmath.h b/libstdc++-v3/include/c_compatibility/tgmath.h
> index aadddd91b60..6bf6727a15c 100644
> --- a/libstdc++-v3/include/c_compatibility/tgmath.h
> +++ b/libstdc++-v3/include/c_compatibility/tgmath.h
> @@ -32,11 +32,12 @@
>   #include <bits/c++config.h>
>   
>   #if __cplusplus >= 201103L
> -# include <ctgmath>
> -#else
> -# if _GLIBCXX_HAVE_TGMATH_H
> -#  include_next <tgmath.h>
> -# endif
> +# include <cmath>
> +extern "C++" {
> +# include <complex>
> +}
> +#elif _GLIBCXX_HAVE_TGMATH_H
> +# include_next <tgmath.h>
>   #endif
>   
>   #endif
> diff --git a/libstdc++-v3/include/c_global/ccomplex b/libstdc++-v3/include/c_global/ccomplex
> index ee1166aaecb..b0e30fa67eb 100644
> --- a/libstdc++-v3/include/c_global/ccomplex
> +++ b/libstdc++-v3/include/c_global/ccomplex
> @@ -41,4 +41,13 @@ extern "C++" {
>   #include <complex>
>   }
>   
> +#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
> +#  error "<ccomplex> is not a standard header in C++20, use <complex.h>"
> +#elif __cplusplus >= 201703L && defined __DEPRECATED
> +#  pragma GCC diagnostic push
> +#  pragma GCC diagnostic ignored "-Wc++23-extensions"
> +#  warning "<ccomplex> is deprecated in C++17, use <complex.h>"
> +#  pragma GCC diagnostic pop
> +#endif
> +
>   #endif
> diff --git a/libstdc++-v3/include/c_global/ciso646 b/libstdc++-v3/include/c_global/ciso646
> index 6e26f9be12e..ed1fcf6f14e 100644
> --- a/libstdc++-v3/include/c_global/ciso646
> +++ b/libstdc++-v3/include/c_global/ciso646
> @@ -38,4 +38,13 @@
>   
>   #include <bits/c++config.h>
>   
> +#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
> +#  error "<ciso646> is not a standard header in C++20, use <iso646.h> or <version>"
> +#elif __cplusplus >= 201703L && defined __DEPRECATED
> +#  pragma GCC diagnostic push
> +#  pragma GCC diagnostic ignored "-Wc++23-extensions"
> +#  warning "<ciso646> is deprecated in C++17, use <iso646.h> or <version>"
> +#  pragma GCC diagnostic pop
> +#endif
> +
>   #endif
> diff --git a/libstdc++-v3/include/c_global/cstdalign b/libstdc++-v3/include/c_global/cstdalign
> index 4f610588425..f7bbbad82a0 100644
> --- a/libstdc++-v3/include/c_global/cstdalign
> +++ b/libstdc++-v3/include/c_global/cstdalign
> @@ -40,6 +40,14 @@
>   #  if _GLIBCXX_HAVE_STDALIGN_H
>   #    include <stdalign.h>
>   #  endif
> +#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
> +#    error "<cstdalign> is not a standard header in C++20, use <stdalign.h>"
> +#  elif __cplusplus >= 201703L && defined __DEPRECATED
> +#    pragma GCC diagnostic push
> +#    pragma GCC diagnostic ignored "-Wc++23-extensions"
> +#    warning "<cstdalign> is deprecated in C++17, use <stdalign.h>"
> +#    pragma GCC diagnostic pop
> +#  endif
>   #endif
>   
>   #endif
> diff --git a/libstdc++-v3/include/c_global/cstdbool b/libstdc++-v3/include/c_global/cstdbool
> index 8d2e75df33f..27be50ff510 100644
> --- a/libstdc++-v3/include/c_global/cstdbool
> +++ b/libstdc++-v3/include/c_global/cstdbool
> @@ -40,6 +40,14 @@
>   #  if _GLIBCXX_HAVE_STDBOOL_H
>   #    include <stdbool.h>
>   #  endif
> +#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
> +#    error "<cstdbool> is not a standard header in C++20, use <stdbool.h>"
> +#  elif __cplusplus >= 201703L && defined __DEPRECATED
> +#    pragma GCC diagnostic push
> +#    pragma GCC diagnostic ignored "-Wc++23-extensions"
> +#    warning "<cstdbool> is deprecated in C++17, use <stdbool.h>"
> +#    pragma GCC diagnostic pop
> +#  endif
>   #endif
>   
>   #endif
> diff --git a/libstdc++-v3/include/c_global/ctgmath b/libstdc++-v3/include/c_global/ctgmath
> index 79c1a029f41..5824a20c7c0 100644
> --- a/libstdc++-v3/include/c_global/ctgmath
> +++ b/libstdc++-v3/include/c_global/ctgmath
> @@ -26,13 +26,13 @@
>    *  This is a Standard C++ Library header.
>    */
>   
> +#ifndef _GLIBCXX_CTGMATH
> +#define _GLIBCXX_CTGMATH 1
> +
>   #ifdef _GLIBCXX_SYSHDR
>   #pragma GCC system_header
>   #endif
>   
> -#ifndef _GLIBCXX_CTGMATH
> -#define _GLIBCXX_CTGMATH 1
> -
>   #if __cplusplus < 201103L
>   #  include <bits/c++0x_warning.h>
>   #else
> @@ -40,6 +40,14 @@
>   extern "C++" {
>   #  include <complex>
>   }
> +#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
> +#    error "<ctgmath> is not a standard header in C++20, use <tgmath.h>"
> +#  elif __cplusplus >= 201703L && defined __DEPRECATED
> +#    pragma GCC diagnostic push
> +#    pragma GCC diagnostic ignored "-Wc++23-extensions"
> +#    warning "<ctgmath> is deprecated in C++17, use <tgmath.h>"
> +#    pragma GCC diagnostic pop
> +#  endif
>   #endif
>   
>   #endif
> diff --git a/libstdc++-v3/include/c_std/ciso646 b/libstdc++-v3/include/c_std/ciso646
> index 7971f0d0c31..ac9801aef2b 100644
> --- a/libstdc++-v3/include/c_std/ciso646
> +++ b/libstdc++-v3/include/c_std/ciso646
> @@ -37,4 +37,14 @@
>   #endif
>   
>   #include <bits/c++config.h>
> +
> +#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
> +#  error "<ciso646> is not a standard header in C++20, use <iso646.h> or <version>"
> +#elif __cplusplus >= 201703L && defined __DEPRECATED
> +#  pragma GCC diagnostic push
> +#  pragma GCC diagnostic ignored "-Wc++23-extensions"
> +#  warning "<ciso646> is deprecated in C++17, use <iso646.h> or <version>"
> +#  pragma GCC diagnostic pop
> +#endif
> +
>   #endif
> diff --git a/libstdc++-v3/include/precompiled/stdc++.h b/libstdc++-v3/include/precompiled/stdc++.h
> index 3eef20d1645..89917106bac 100644
> --- a/libstdc++-v3/include/precompiled/stdc++.h
> +++ b/libstdc++-v3/include/precompiled/stdc++.h
> @@ -34,7 +34,6 @@
>   #endif
>   #include <cctype>
>   #include <cfloat>
> -#include <ciso646>
>   #include <climits>
>   #include <csetjmp>
>   #include <cstdarg>
> @@ -43,6 +42,9 @@
>   
>   #if __cplusplus >= 201103L
>   #include <cstdint>
> +#if __cplusplus < 201703L
> +#include <ciso646>
> +#endif
>   #endif
>   
>   // C++
> @@ -108,7 +110,6 @@
>   #include <cctype>
>   #include <cerrno>
>   #include <cfloat>
> -#include <ciso646>
>   #include <climits>
>   #include <clocale>
>   #include <cmath>
> @@ -124,14 +125,16 @@
>   #include <cwctype>
>   
>   #if __cplusplus >= 201103L
> -#include <ccomplex>
>   #include <cfenv>
>   #include <cinttypes>
> +#include <cstdint>
> +#include <cuchar>
> +#if __cplusplus < 201703L
> +#include <ccomplex>
>   #include <cstdalign>
>   #include <cstdbool>
> -#include <cstdint>
>   #include <ctgmath>
> -#include <cuchar>
> +#endif
>   #endif
>   
>   // C++
> diff --git a/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
> new file mode 100644
> index 00000000000..ab3a041de06
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
> @@ -0,0 +1,51 @@
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated -fno-operator-names" }
> +// { dg-do preprocess }
> +
> +#include <ciso646>
> +
> +// { dg-warning "deprecated" "" { target c++17_only } 0 }
> +// { dg-error "not a standard header" "" { target c++20 } 0 }
> +
> +#ifdef and
> +# error "The header <ciso646> defines a macro named and"
> +#endif
> +
> +#ifdef and_eq
> +# error "The header <ciso646> defines a macro named and_eq"
> +#endif
> +
> +#ifdef bitand
> +# error "The header <ciso646> defines a macro named bitand"
> +#endif
> +
> +#ifdef bitor
> +# error "The header <ciso646> defines a macro named bitor"
> +#endif
> +
> +#ifdef compl
> +# error "The header <ciso646> defines a macro named compl"
> +#endif
> +
> +#ifdef not
> +# error "The header <ciso646> defines a macro named not"
> +#endif
> +
> +#ifdef not_eq
> +# error "The header <ciso646> defines a macro named not_eq"
> +#endif
> +
> +#ifdef or
> +# error "The header <ciso646> defines a macro named or"
> +#endif
> +
> +#ifdef or_eq
> +# error "The header <ciso646> defines a macro named or_eq"
> +#endif
> +
> +#ifdef xor
> +# error "The header <ciso646> defines a macro named xor"
> +#endif
> +
> +#ifdef xor_eq
> +# error "The header <ciso646> defines a macro named xor_eq"
> +#endif
> diff --git a/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
> new file mode 100644
> index 00000000000..a70c18de918
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
> @@ -0,0 +1,49 @@
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated -fno-operator-names" }
> +// { dg-do preprocess }
> +// { dg-bogus "deprecated" "C++17 deprecated <ciso646> but not <iso646.h>" }
> +
> +#include <iso646.h>
> +
> +#ifdef and
> +# error "The header <iso646.h> defines a macro named and"
> +#endif
> +
> +#ifdef and_eq
> +# error "The header <iso646.h> defines a macro named and_eq"
> +#endif
> +
> +#ifdef bitand
> +# error "The header <iso646.h> defines a macro named bitand"
> +#endif
> +
> +#ifdef bitor
> +# error "The header <iso646.h> defines a macro named bitor"
> +#endif
> +
> +#ifdef compl
> +# error "The header <iso646.h> defines a macro named compl"
> +#endif
> +
> +#ifdef not
> +# error "The header <iso646.h> defines a macro named not"
> +#endif
> +
> +#ifdef not_eq
> +# error "The header <iso646.h> defines a macro named not_eq"
> +#endif
> +
> +#ifdef or
> +# error "The header <iso646.h> defines a macro named or"
> +#endif
> +
> +#ifdef or_eq
> +# error "The header <iso646.h> defines a macro named or_eq"
> +#endif
> +
> +#ifdef xor
> +# error "The header <iso646.h> defines a macro named xor"
> +#endif
> +
> +#ifdef xor_eq
> +# error "The header <iso646.h> defines a macro named xor_eq"
> +#endif
> diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
> index c50c921cd59..793cd26dfa8 100644
> --- a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
> +++ b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
> @@ -1,8 +1,13 @@
> -// { dg-options "-D_GLIBCXX_USE_DEPRECATED=1 -Wno-deprecated" }
> -// { dg-do preprocess { target c++11 } }
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do preprocess }
>   
>   #include <cstdalign>
>   
> +// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
> +// { dg-warning "deprecated" "" { target c++17_only } 0 }
> +// { dg-error "not a standard header" "" { target c++20 } 0 }
> +
> +#if __cplusplus >= 201103L
>   #ifndef __alignas_is_defined
>   # error "The header <cstdalign> fails to define a macro named  __alignas_is_defined"
>   #elif __alignas_is_defined != 1
> @@ -22,3 +27,4 @@
>   #ifdef alignof
>   # error "The header <cstdalign> defines a macro named alignof"
>   #endif
> +#endif
> diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
> new file mode 100644
> index 00000000000..78f41ae02e8
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
> @@ -0,0 +1,25 @@
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do preprocess { target c++11 } }
> +// { dg-bogus "deprecated" "C++17 deprecated <cstdalign> but not <stdalign.h>" }
> +
> +#include <stdalign.h>
> +
> +#ifndef __alignas_is_defined
> +# error "The header <stdalign.h> fails to define a macro named  __alignas_is_defined"
> +#elif __alignas_is_defined != 1
> +# error "__alignas_is_defined is not defined to 1 in <stdalign.h>"
> +#endif
> +
> +#ifndef __alignof_is_defined
> +# error "The header <stdalign.h> fails to define a macro named __alignof_is_defined"
> +#elif __alignof_is_defined != 1
> +# error "__alignof_is_defined is not defined to 1 in <stdalign.h>"
> +#endif
> +
> +#ifdef alignas
> +# error "The header <stdalign.h> defines a macro named alignas"
> +#endif
> +
> +#ifdef alignof
> +# error "The header <stdalign.h> defines a macro named alignof"
> +#endif
> diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
> deleted file mode 100644
> index 14694f034e6..00000000000
> --- a/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
> +++ /dev/null
> @@ -1,24 +0,0 @@
> -// { dg-options "-std=gnu++98" }
> -// { dg-do compile { target c++98_only } }
> -
> -// Copyright (C) 2011-2024 Free Software Foundation, Inc.
> -//
> -// This file is part of the GNU ISO C++ Library.  This library is free
> -// software; you can redistribute it and/or modify it under the
> -// terms of the GNU General Public License as published by the
> -// Free Software Foundation; either version 3, or (at your option)
> -// any later version.
> -
> -// This library is distributed in the hope that it will be useful,
> -// but WITHOUT ANY WARRANTY; without even the implied warranty of
> -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> -// GNU General Public License for more details.
> -
> -// You should have received a copy of the GNU General Public License along
> -// with this library; see the file COPYING3.  If not see
> -// <http://www.gnu.org/licenses/>.
> -
> -#include <cstdalign>
> -
> -// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
> -
> diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
> index e0afc26e458..658a02a4565 100644
> --- a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
> +++ b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
> @@ -1,4 +1,5 @@
> -// { dg-do compile { target c++11 } }
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do preprocess }
>   
>   // Copyright (C) 2012-2024 Free Software Foundation, Inc.
>   //
> @@ -19,6 +20,11 @@
>   
>   #include <cstdbool>
>   
> +// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
> +// { dg-warning "deprecated" "" { target c++17_only } 0 }
> +// { dg-error "not a standard header" "" { target c++20 } 0 }
> +
> +#if __cplusplus >= 201103L
>   #ifndef __bool_true_false_are_defined
>   # error "The header <cstdbool> fails to define a macro named __bool_true_false_are_defined"
>   #endif
> @@ -34,3 +40,4 @@
>   #ifdef false
>   # error "The header <cstdbool> defines a macro named false"
>   #endif
> +#endif
> diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
> new file mode 100644
> index 00000000000..a3c0f9a0aec
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
> @@ -0,0 +1,21 @@
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do preprocess { target c++11 } }
> +// { dg-bogus "deprecated" "C++17 deprecated <cstdbool> but not <stdbool.h>" }
> +
> +#include <stdbool.h>
> +
> +#ifndef __bool_true_false_are_defined
> +# error "The header <stdbool.h> fails to define a macro named __bool_true_false_are_defined"
> +#endif
> +
> +#ifdef bool
> +# error "The header <stdbool.h> defines a macro named bool"
> +#endif
> +
> +#ifdef true
> +# error "The header <stdbool.h> defines a macro named true"
> +#endif
> +
> +#ifdef false
> +# error "The header <stdbool.h> defines a macro named false"
> +#endif
> diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
> deleted file mode 100644
> index 5b8c5688877..00000000000
> --- a/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
> +++ /dev/null
> @@ -1,26 +0,0 @@
> -// { dg-options "-std=gnu++98" }
> -// { dg-do compile { target c++98_only } }
> -
> -// Copyright (C) 2007-2024 Free Software Foundation, Inc.
> -//
> -// This file is part of the GNU ISO C++ Library.  This library is free
> -// software; you can redistribute it and/or modify it under the
> -// terms of the GNU General Public License as published by the
> -// Free Software Foundation; either version 3, or (at your option)
> -// any later version.
> -
> -// This library is distributed in the hope that it will be useful,
> -// but WITHOUT ANY WARRANTY; without even the implied warranty of
> -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> -// GNU General Public License for more details.
> -
> -// You should have received a copy of the GNU General Public License along
> -// with this library; see the file COPYING3.  If not see
> -// <http://www.gnu.org/licenses/>.
> -
> -#include <cstdbool>
> -
> -// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
> -
> -
> -
> diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
> new file mode 100644
> index 00000000000..d6c33781ae5
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
> @@ -0,0 +1,10 @@
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do compile }
> +
> +#include <ccomplex>
> +
> +std::complex<double> d;
> +
> +// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
> +// { dg-warning "deprecated" "" { target c++17_only } 0 }
> +// { dg-error "not a standard header" "" { target c++20 } 0 }
> diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
> new file mode 100644
> index 00000000000..318b78ee89e
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
> @@ -0,0 +1,10 @@
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do compile }
> +// { dg-bogus "deprecated" "C++17 deprecated <ccomplex> but not <complex.h>" }
> +
> +#include <complex.h>
> +
> +#if __cplusplus < 201103L
> +# undef complex
> +#endif
> +std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
> diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
> deleted file mode 100644
> index 16c623b25b0..00000000000
> --- a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
> +++ /dev/null
> @@ -1,26 +0,0 @@
> -// { dg-options "-std=gnu++98" }
> -// { dg-do compile { target c++98_only } }
> -
> -// Copyright (C) 2007-2024 Free Software Foundation, Inc.
> -//
> -// This file is part of the GNU ISO C++ Library.  This library is free
> -// software; you can redistribute it and/or modify it under the
> -// terms of the GNU General Public License as published by the
> -// Free Software Foundation; either version 3, or (at your option)
> -// any later version.
> -
> -// This library is distributed in the hope that it will be useful,
> -// but WITHOUT ANY WARRANTY; without even the implied warranty of
> -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> -// GNU General Public License for more details.
> -
> -// You should have received a copy of the GNU General Public License along
> -// with this library; see the file COPYING3.  If not see
> -// <http://www.gnu.org/licenses/>.
> -
> -#include <ccomplex>
> -
> -// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
> -
> -
> -
> diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
> index a2c4a55c89b..ef2bbd0e20a 100644
> --- a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
> +++ b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
> @@ -15,8 +15,13 @@
>   // with this library; see the file COPYING3.  If not see
>   // <http://www.gnu.org/licenses/>.
>   
> -// { dg-do compile { target c++11 } }
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do compile }
>   
>   #include <ctgmath>
>   
> -std::complex<double> d;
> +std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
> +
> +// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
> +// { dg-warning "deprecated" "" { target c++17_only } 0 }
> +// { dg-error "not a standard header" "" { target c++20 } 0 }
> diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
> new file mode 100644
> index 00000000000..fd6847bff4f
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
> @@ -0,0 +1,10 @@
> +// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
> +// { dg-do compile }
> +// { dg-bogus "deprecated" "C++17 deprecated <ctgmath> but not <tgmath.h>" }
> +
> +#include <tgmath.h>
> +
> +#if __cplusplus < 201103L
> +# undef complex
> +#endif
> +std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
> diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
> deleted file mode 100644
> index d693c8b23ed..00000000000
> --- a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
> +++ /dev/null
> @@ -1,26 +0,0 @@
> -// { dg-options "-std=gnu++98" }
> -// { dg-do compile { target c++98_only } }
> -
> -// Copyright (C) 2007-2024 Free Software Foundation, Inc.
> -//
> -// This file is part of the GNU ISO C++ Library.  This library is free
> -// software; you can redistribute it and/or modify it under the
> -// terms of the GNU General Public License as published by the
> -// Free Software Foundation; either version 3, or (at your option)
> -// any later version.
> -
> -// This library is distributed in the hope that it will be useful,
> -// but WITHOUT ANY WARRANTY; without even the implied warranty of
> -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> -// GNU General Public License for more details.
> -
> -// You should have received a copy of the GNU General Public License along
> -// with this library; see the file COPYING3.  If not see
> -// <http://www.gnu.org/licenses/>.
> -
> -#include <ctgmath>
> -
> -// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
> -
> -
> -
> diff --git a/libstdc++-v3/testsuite/27_io/objects/char/1.cc b/libstdc++-v3/testsuite/27_io/objects/char/1.cc
> index 9fc9244baf4..d50b3884702 100644
> --- a/libstdc++-v3/testsuite/27_io/objects/char/1.cc
> +++ b/libstdc++-v3/testsuite/27_io/objects/char/1.cc
> @@ -53,7 +53,6 @@
>   #include <cctype>
>   #include <cerrno>
>   #include <cfloat>
> -#include <ciso646>
>   #include <climits>
>   #include <clocale>
>   #include <cmath>
> diff --git a/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc b/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
> index 23b2168805d..c2f3643b4e5 100644
> --- a/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
> +++ b/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
> @@ -53,7 +53,6 @@
>   #include <cctype>
>   #include <cerrno>
>   #include <cfloat>
> -#include <ciso646>
>   #include <climits>
>   #include <clocale>
>   #include <cmath>
Jonathan Wakely Nov. 1, 2024, 8:56 p.m. UTC | #2
On 31/10/24 20:09 +0000, Jonathan Wakely wrote:
>Tested x86_64-linux. Is the g++ test change OK?
>
>Also available for review at:
>https://forge.sourceware.org/gcc/gcc-TEST/pulls/4
>
>-- >8 --
>
>These headers make no sense for C++ programs, because they either define
>different content to the corresponding <xxx.h> C header, or define
>nothing at all in namespace std. They were all deprecated in C++17, so
>add deprecation warnings to them, which can be disabled with
>-Wno-deprecated. For C++20 and later these headers are no longer in the
>standard at all, so compiling with _GLIBCXX_USE_DEPRECATED defined to 0
>will give an error when they are included.
>
>Because #warning is non-standard before C++23 we need to use pragmas to
>ignore -Wc++23-extensions for the -Wsystem-headers -pedantic case.
>
>One g++ test needs adjustment because it includes <ciso646>, but that
>can be made conditional on the __cplusplus value without any reduction
>in test coverage.
>
>For the library tests, consolidate the std_c++0x_neg.cc XFAIL tests into
>the macros.cc test, using dg-error with a { target c++98_only }
>selector. This avoids having two separate test files, one for C++98 and
>one for everything later. Also add tests for the <xxx.h> headers to
>ensure that they behave as expected and don't give deprecated warnings.
>
>libstdc++-v3/ChangeLog:
>
>	* doc/xml/manual/evolution.xml: Document deprecations.
>	* doc/html/*: Regenerate.
>	* include/c_compatibility/complex.h (_GLIBCXX_COMPLEX_H): Move
>	include guard to start of file. Include <complex> directly
>	instead of <ccomplex>.
>	* include/c_compatibility/tgmath.h: Include <cmath> and
>	<complex> directly, instead of <ctgmath>.
>	* include/c_global/ccomplex: Add deprecated #warning for C++17
>	and #error for C++20 if _GLIBCXX_USE_DEPRECATED == 0.
>	* include/c_global/ciso646: Likewise.
>	* include/c_global/cstdalign: Likewise.
>	* include/c_global/cstdbool: Likewise.
>	* include/c_global/ctgmath: Likewise.
>	* include/c_std/ciso646: Likewise.
>	* include/precompiled/stdc++.h: Do not include ccomplex,
>	ciso646, cstdalign, cstdbool, or ctgmath in C++17 and later.
>	* testsuite/18_support/headers/cstdalign/macros.cc: Check for
>	warnings and errors for unsupported dialects.
>	* testsuite/18_support/headers/cstdbool/macros.cc: Likewise.
>	* testsuite/26_numerics/headers/ctgmath/complex.cc: Likewise.
>	* testsuite/27_io/objects/char/1.cc: Do not include <ciso646>.
>	* testsuite/27_io/objects/wchar_t/1.cc: Likewise.
>	* testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc: Removed.
>	* testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc: Removed.
>	* testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc: Removed.
>	* testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc: Removed.
>	* testsuite/18_support/headers/ciso646/macros.cc: New test.
>	* testsuite/18_support/headers/ciso646/macros.h.cc: New test.
>	* testsuite/18_support/headers/cstdbool/macros.h.cc: New test.
>	* testsuite/26_numerics/headers/ccomplex/complex.cc: New test.
>	* testsuite/26_numerics/headers/ccomplex/complex.h.cc: New test.
>	* testsuite/26_numerics/headers/ctgmath/complex.h.cc: New test.
>
>gcc/testsuite/ChangeLog:
>
>	* g++.old-deja/g++.other/headers1.C: Do not include ciso646 for
>	C++17 and later.
>---
> .../g++.old-deja/g++.other/headers1.C         |  2 +
> libstdc++-v3/doc/html/manual/api.html         |  8 +++
> libstdc++-v3/doc/xml/manual/evolution.xml     | 10 ++++
> .../include/c_compatibility/complex.h         | 10 ++--
> libstdc++-v3/include/c_compatibility/tgmath.h | 11 ++--
> libstdc++-v3/include/c_global/ccomplex        |  9 ++++
> libstdc++-v3/include/c_global/ciso646         |  9 ++++
> libstdc++-v3/include/c_global/cstdalign       |  8 +++
> libstdc++-v3/include/c_global/cstdbool        |  8 +++
> libstdc++-v3/include/c_global/ctgmath         | 14 +++--
> libstdc++-v3/include/c_std/ciso646            | 10 ++++
> libstdc++-v3/include/precompiled/stdc++.h     | 13 +++--
> .../18_support/headers/ciso646/macros.cc      | 51 +++++++++++++++++++
> .../18_support/headers/ciso646/macros.h.cc    | 49 ++++++++++++++++++
> .../18_support/headers/cstdalign/macros.cc    | 10 +++-
> .../18_support/headers/cstdalign/macros.h.cc  | 25 +++++++++
> .../headers/cstdalign/std_c++0x_neg.cc        | 24 ---------
> .../18_support/headers/cstdbool/macros.cc     |  9 +++-
> .../18_support/headers/cstdbool/macros.h.cc   | 21 ++++++++
> .../headers/cstdbool/std_c++0x_neg.cc         | 26 ----------
> .../26_numerics/headers/ccomplex/complex.cc   | 10 ++++
> .../26_numerics/headers/ccomplex/complex.h.cc | 10 ++++
> .../headers/ccomplex/std_c++0x_neg.cc         | 26 ----------
> .../26_numerics/headers/ctgmath/complex.cc    |  9 +++-
> .../26_numerics/headers/ctgmath/complex.h.cc  | 10 ++++
> .../headers/ctgmath/std_c++0x_neg.cc          | 26 ----------
> .../testsuite/27_io/objects/char/1.cc         |  1 -
> .../testsuite/27_io/objects/wchar_t/1.cc      |  1 -
> 28 files changed, 294 insertions(+), 126 deletions(-)
> create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
> create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
> create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
> delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
> create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
> delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
> delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
> create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
> delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
>
>diff --git a/gcc/testsuite/g++.old-deja/g++.other/headers1.C b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
>index 5d37e94082f..90a1a7dc8f9 100644
>--- a/gcc/testsuite/g++.old-deja/g++.other/headers1.C
>+++ b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
>@@ -12,7 +12,9 @@
> #include <cctype>
> #include <cerrno>
> #include <cfloat>
>+#if __cplusplus < 201703L
> #include <ciso646>
>+#endif
> #include <climits>
> #include <clocale>
> #include <cmath>
>diff --git a/libstdc++-v3/doc/html/manual/api.html b/libstdc++-v3/doc/html/manual/api.html
>index 799f6eae2a2..2ccfc07b83e 100644
>--- a/libstdc++-v3/doc/html/manual/api.html
>+++ b/libstdc++-v3/doc/html/manual/api.html
>@@ -498,4 +498,12 @@ to be used with <code class="code">std::basic_istream</code>.
>   longer allowed in C++20 mode.
> </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_151"></a><code class="constant">15</code></h3></div></div></div><p>
> Enabled debug assertions by default for unoptimized builds.
>+</p><p>
>+Added warnings when including the headers that were deprecated in C++17
>+and removed in C++20:
>+<code class="filename">&lt;ccomplex&gt;</code>,
>+<code class="filename">&lt;ciso646&gt;</code>,
>+<code class="filename">&lt;cstdalign&gt;</code>,
>+<code class="filename">&lt;cstdbool&gt;</code>, and
>+<code class="filename">&lt;ctgmath&gt;</code>.
> </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="abi.html">Prev</a>??</td><td width="20%" align="center"><a accesskey="u" href="appendix_porting.html">Up</a></td><td width="40%" align="right">??<a accesskey="n" href="backwards.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ABI Policy and Guidelines??</td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top">??Backwards Compatibility</td></tr></table></div></body></html>
>\ No newline at end of file
>diff --git a/libstdc++-v3/doc/xml/manual/evolution.xml b/libstdc++-v3/doc/xml/manual/evolution.xml
>index 75cf948a4a2..6b134de0e71 100644
>--- a/libstdc++-v3/doc/xml/manual/evolution.xml
>+++ b/libstdc++-v3/doc/xml/manual/evolution.xml
>@@ -1135,6 +1135,16 @@ to be used with <code>std::basic_istream</code>.
> Enabled debug assertions by default for unoptimized builds.
> </para>
>
>+<para>
>+Added warnings when including the headers that were deprecated in C++17
>+and removed in C++20:
>+<filename class="headerfile">&lt;ccomplex&gt;</filename>,
>+<filename class="headerfile">&lt;ciso646&gt;</filename>,
>+<filename class="headerfile">&lt;cstdalign&gt;</filename>,
>+<filename class="headerfile">&lt;cstdbool&gt;</filename>, and
>+<filename class="headerfile">&lt;ctgmath&gt;</filename>.
>+</para>
>+
> </section>
>
> </section>
>diff --git a/libstdc++-v3/include/c_compatibility/complex.h b/libstdc++-v3/include/c_compatibility/complex.h
>index 605d1f30e06..461ff2117b1 100644
>--- a/libstdc++-v3/include/c_compatibility/complex.h
>+++ b/libstdc++-v3/include/c_compatibility/complex.h
>@@ -26,10 +26,15 @@
>  *  This is a Standard C++ Library header.
>  */
>
>+#ifndef _GLIBCXX_COMPLEX_H
>+#define _GLIBCXX_COMPLEX_H 1
>+
> #include <bits/c++config.h>
>
> #if __cplusplus >= 201103L
>-# include <ccomplex>
>+extern "C++" {
>+#include <complex>
>+}
> #endif
>
> #if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
>@@ -42,7 +47,4 @@
> # endif
> #endif
>
>-#ifndef _GLIBCXX_COMPLEX_H
>-#define _GLIBCXX_COMPLEX_H 1
>-
> #endif
>diff --git a/libstdc++-v3/include/c_compatibility/tgmath.h b/libstdc++-v3/include/c_compatibility/tgmath.h
>index aadddd91b60..6bf6727a15c 100644
>--- a/libstdc++-v3/include/c_compatibility/tgmath.h
>+++ b/libstdc++-v3/include/c_compatibility/tgmath.h
>@@ -32,11 +32,12 @@
> #include <bits/c++config.h>
>
> #if __cplusplus >= 201103L
>-# include <ctgmath>
>-#else
>-# if _GLIBCXX_HAVE_TGMATH_H
>-#  include_next <tgmath.h>
>-# endif
>+# include <cmath>
>+extern "C++" {
>+# include <complex>
>+}
>+#elif _GLIBCXX_HAVE_TGMATH_H
>+# include_next <tgmath.h>
> #endif
>
> #endif
>diff --git a/libstdc++-v3/include/c_global/ccomplex b/libstdc++-v3/include/c_global/ccomplex
>index ee1166aaecb..b0e30fa67eb 100644
>--- a/libstdc++-v3/include/c_global/ccomplex
>+++ b/libstdc++-v3/include/c_global/ccomplex
>@@ -41,4 +41,13 @@ extern "C++" {
> #include <complex>
> }
>
>+#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
>+#  error "<ccomplex> is not a standard header in C++20, use <complex.h>"
>+#elif __cplusplus >= 201703L && defined __DEPRECATED
>+#  pragma GCC diagnostic push
>+#  pragma GCC diagnostic ignored "-Wc++23-extensions"
>+#  warning "<ccomplex> is deprecated in C++17, use <complex.h>"

I'm not sure whether we should suggest <complex.h> or <complex> here.

It's hard to know what users might have intended when including
<ccomplex>. I suppose we should suggest <complex>, since that's what
they got for <ccomplex> in C++11 and C++14.

>+#  pragma GCC diagnostic pop
>+#endif
>+
> #endif
>diff --git a/libstdc++-v3/include/c_global/ciso646 b/libstdc++-v3/include/c_global/ciso646
>index 6e26f9be12e..ed1fcf6f14e 100644
>--- a/libstdc++-v3/include/c_global/ciso646
>+++ b/libstdc++-v3/include/c_global/ciso646
>@@ -38,4 +38,13 @@
>
> #include <bits/c++config.h>
>
>+#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
>+#  error "<ciso646> is not a standard header in C++20, use <iso646.h> or <version>"
>+#elif __cplusplus >= 201703L && defined __DEPRECATED
>+#  pragma GCC diagnostic push
>+#  pragma GCC diagnostic ignored "-Wc++23-extensions"
>+#  warning "<ciso646> is deprecated in C++17, use <iso646.h> or <version>"

There's no reason to include <ciso646> _except_ as a cheap header that
can be used to detect which std::lib you're using, e.g. as Howard used
to recommend:
https://stackoverflow.com/a/13220861/981959
https://stackoverflow.com/a/18832356/981959
The modern way to do that is <version>, but maybe <iso646.h> makes
more sense if somebody was including ciso46 for some other reason
(what reason though?)

>+#  pragma GCC diagnostic pop
>+#endif
>+
> #endif
>diff --git a/libstdc++-v3/include/c_global/cstdalign b/libstdc++-v3/include/c_global/cstdalign
>index 4f610588425..f7bbbad82a0 100644
>--- a/libstdc++-v3/include/c_global/cstdalign
>+++ b/libstdc++-v3/include/c_global/cstdalign
>@@ -40,6 +40,14 @@
> #  if _GLIBCXX_HAVE_STDALIGN_H
> #    include <stdalign.h>
> #  endif
>+#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
>+#    error "<cstdalign> is not a standard header in C++20, use <stdalign.h>"
>+#  elif __cplusplus >= 201703L && defined __DEPRECATED
>+#    pragma GCC diagnostic push
>+#    pragma GCC diagnostic ignored "-Wc++23-extensions"
>+#    warning "<cstdalign> is deprecated in C++17, use <stdalign.h>"

Should we suggest <stdalign.h>, or suggest simply removing <cstdalign>?

There's no reason to include <cstdalign> in C++ code, and just as
little reason to include <stdalign.h>

>+#    pragma GCC diagnostic pop
>+#  endif
> #endif
>
> #endif
>diff --git a/libstdc++-v3/include/c_global/cstdbool b/libstdc++-v3/include/c_global/cstdbool
>index 8d2e75df33f..27be50ff510 100644
>--- a/libstdc++-v3/include/c_global/cstdbool
>+++ b/libstdc++-v3/include/c_global/cstdbool
>@@ -40,6 +40,14 @@
> #  if _GLIBCXX_HAVE_STDBOOL_H
> #    include <stdbool.h>
> #  endif
>+#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
>+#    error "<cstdbool> is not a standard header in C++20, use <stdbool.h>"
>+#  elif __cplusplus >= 201703L && defined __DEPRECATED
>+#    pragma GCC diagnostic push
>+#    pragma GCC diagnostic ignored "-Wc++23-extensions"
>+#    warning "<cstdbool> is deprecated in C++17, use <stdbool.h>"

Ditto. <stdbool.h> or just remove <cstdbool>?

>+#    pragma GCC diagnostic pop
>+#  endif
> #endif
>
> #endif
>diff --git a/libstdc++-v3/include/c_global/ctgmath b/libstdc++-v3/include/c_global/ctgmath
>index 79c1a029f41..5824a20c7c0 100644
>--- a/libstdc++-v3/include/c_global/ctgmath
>+++ b/libstdc++-v3/include/c_global/ctgmath
>@@ -26,13 +26,13 @@
>  *  This is a Standard C++ Library header.
>  */
>
>+#ifndef _GLIBCXX_CTGMATH
>+#define _GLIBCXX_CTGMATH 1
>+
> #ifdef _GLIBCXX_SYSHDR
> #pragma GCC system_header
> #endif
>
>-#ifndef _GLIBCXX_CTGMATH
>-#define _GLIBCXX_CTGMATH 1
>-
> #if __cplusplus < 201103L
> #  include <bits/c++0x_warning.h>
> #else
>@@ -40,6 +40,14 @@
> extern "C++" {
> #  include <complex>
> }
>+#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
>+#    error "<ctgmath> is not a standard header in C++20, use <tgmath.h>"
>+#  elif __cplusplus >= 201703L && defined __DEPRECATED
>+#    pragma GCC diagnostic push
>+#    pragma GCC diagnostic ignored "-Wc++23-extensions"
>+#    warning "<ctgmath> is deprecated in C++17, use <tgmath.h>"

Include <complex>, or <cmath>, or <tgmath.h>?

>+#    pragma GCC diagnostic pop
>+#  endif
> #endif
>
> #endif
>diff --git a/libstdc++-v3/include/c_std/ciso646 b/libstdc++-v3/include/c_std/ciso646
>index 7971f0d0c31..ac9801aef2b 100644
>--- a/libstdc++-v3/include/c_std/ciso646
>+++ b/libstdc++-v3/include/c_std/ciso646
>@@ -37,4 +37,14 @@
> #endif
>
> #include <bits/c++config.h>
>+
>+#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
>+#  error "<ciso646> is not a standard header in C++20, use <iso646.h> or <version>"
>+#elif __cplusplus >= 201703L && defined __DEPRECATED
>+#  pragma GCC diagnostic push
>+#  pragma GCC diagnostic ignored "-Wc++23-extensions"
>+#  warning "<ciso646> is deprecated in C++17, use <iso646.h> or <version>"
>+#  pragma GCC diagnostic pop
>+#endif
>+
> #endif
>diff --git a/libstdc++-v3/include/precompiled/stdc++.h b/libstdc++-v3/include/precompiled/stdc++.h
>index 3eef20d1645..89917106bac 100644
>--- a/libstdc++-v3/include/precompiled/stdc++.h
>+++ b/libstdc++-v3/include/precompiled/stdc++.h
>@@ -34,7 +34,6 @@
> #endif
> #include <cctype>
> #include <cfloat>
>-#include <ciso646>
> #include <climits>
> #include <csetjmp>
> #include <cstdarg>
>@@ -43,6 +42,9 @@
>
> #if __cplusplus >= 201103L
> #include <cstdint>
>+#if __cplusplus < 201703L
>+#include <ciso646>
>+#endif
> #endif
>
> // C++
>@@ -108,7 +110,6 @@
> #include <cctype>
> #include <cerrno>
> #include <cfloat>
>-#include <ciso646>
> #include <climits>
> #include <clocale>
> #include <cmath>
>@@ -124,14 +125,16 @@
> #include <cwctype>
>
> #if __cplusplus >= 201103L
>-#include <ccomplex>
> #include <cfenv>
> #include <cinttypes>
>+#include <cstdint>
>+#include <cuchar>
>+#if __cplusplus < 201703L
>+#include <ccomplex>
> #include <cstdalign>
> #include <cstdbool>
>-#include <cstdint>
> #include <ctgmath>
>-#include <cuchar>
>+#endif
> #endif
>
> // C++
>diff --git a/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
>new file mode 100644
>index 00000000000..ab3a041de06
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
>@@ -0,0 +1,51 @@
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated -fno-operator-names" }
>+// { dg-do preprocess }
>+
>+#include <ciso646>
>+
>+// { dg-warning "deprecated" "" { target c++17_only } 0 }
>+// { dg-error "not a standard header" "" { target c++20 } 0 }
>+
>+#ifdef and
>+# error "The header <ciso646> defines a macro named and"
>+#endif
>+
>+#ifdef and_eq
>+# error "The header <ciso646> defines a macro named and_eq"
>+#endif
>+
>+#ifdef bitand
>+# error "The header <ciso646> defines a macro named bitand"
>+#endif
>+
>+#ifdef bitor
>+# error "The header <ciso646> defines a macro named bitor"
>+#endif
>+
>+#ifdef compl
>+# error "The header <ciso646> defines a macro named compl"
>+#endif
>+
>+#ifdef not
>+# error "The header <ciso646> defines a macro named not"
>+#endif
>+
>+#ifdef not_eq
>+# error "The header <ciso646> defines a macro named not_eq"
>+#endif
>+
>+#ifdef or
>+# error "The header <ciso646> defines a macro named or"
>+#endif
>+
>+#ifdef or_eq
>+# error "The header <ciso646> defines a macro named or_eq"
>+#endif
>+
>+#ifdef xor
>+# error "The header <ciso646> defines a macro named xor"
>+#endif
>+
>+#ifdef xor_eq
>+# error "The header <ciso646> defines a macro named xor_eq"
>+#endif
>diff --git a/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
>new file mode 100644
>index 00000000000..a70c18de918
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
>@@ -0,0 +1,49 @@
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated -fno-operator-names" }
>+// { dg-do preprocess }
>+// { dg-bogus "deprecated" "C++17 deprecated <ciso646> but not <iso646.h>" }
>+
>+#include <iso646.h>
>+
>+#ifdef and
>+# error "The header <iso646.h> defines a macro named and"
>+#endif
>+
>+#ifdef and_eq
>+# error "The header <iso646.h> defines a macro named and_eq"
>+#endif
>+
>+#ifdef bitand
>+# error "The header <iso646.h> defines a macro named bitand"
>+#endif
>+
>+#ifdef bitor
>+# error "The header <iso646.h> defines a macro named bitor"
>+#endif
>+
>+#ifdef compl
>+# error "The header <iso646.h> defines a macro named compl"
>+#endif
>+
>+#ifdef not
>+# error "The header <iso646.h> defines a macro named not"
>+#endif
>+
>+#ifdef not_eq
>+# error "The header <iso646.h> defines a macro named not_eq"
>+#endif
>+
>+#ifdef or
>+# error "The header <iso646.h> defines a macro named or"
>+#endif
>+
>+#ifdef or_eq
>+# error "The header <iso646.h> defines a macro named or_eq"
>+#endif
>+
>+#ifdef xor
>+# error "The header <iso646.h> defines a macro named xor"
>+#endif
>+
>+#ifdef xor_eq
>+# error "The header <iso646.h> defines a macro named xor_eq"
>+#endif
>diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
>index c50c921cd59..793cd26dfa8 100644
>--- a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
>+++ b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
>@@ -1,8 +1,13 @@
>-// { dg-options "-D_GLIBCXX_USE_DEPRECATED=1 -Wno-deprecated" }
>-// { dg-do preprocess { target c++11 } }
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do preprocess }
>
> #include <cstdalign>
>
>+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
>+// { dg-warning "deprecated" "" { target c++17_only } 0 }
>+// { dg-error "not a standard header" "" { target c++20 } 0 }
>+
>+#if __cplusplus >= 201103L
> #ifndef __alignas_is_defined
> # error "The header <cstdalign> fails to define a macro named  __alignas_is_defined"
> #elif __alignas_is_defined != 1
>@@ -22,3 +27,4 @@
> #ifdef alignof
> # error "The header <cstdalign> defines a macro named alignof"
> #endif
>+#endif
>diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
>new file mode 100644
>index 00000000000..78f41ae02e8
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
>@@ -0,0 +1,25 @@
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do preprocess { target c++11 } }
>+// { dg-bogus "deprecated" "C++17 deprecated <cstdalign> but not <stdalign.h>" }
>+
>+#include <stdalign.h>
>+
>+#ifndef __alignas_is_defined
>+# error "The header <stdalign.h> fails to define a macro named  __alignas_is_defined"
>+#elif __alignas_is_defined != 1
>+# error "__alignas_is_defined is not defined to 1 in <stdalign.h>"
>+#endif
>+
>+#ifndef __alignof_is_defined
>+# error "The header <stdalign.h> fails to define a macro named __alignof_is_defined"
>+#elif __alignof_is_defined != 1
>+# error "__alignof_is_defined is not defined to 1 in <stdalign.h>"
>+#endif
>+
>+#ifdef alignas
>+# error "The header <stdalign.h> defines a macro named alignas"
>+#endif
>+
>+#ifdef alignof
>+# error "The header <stdalign.h> defines a macro named alignof"
>+#endif
>diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
>deleted file mode 100644
>index 14694f034e6..00000000000
>--- a/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
>+++ /dev/null
>@@ -1,24 +0,0 @@
>-// { dg-options "-std=gnu++98" }
>-// { dg-do compile { target c++98_only } }
>-
>-// Copyright (C) 2011-2024 Free Software Foundation, Inc.
>-//
>-// This file is part of the GNU ISO C++ Library.  This library is free
>-// software; you can redistribute it and/or modify it under the
>-// terms of the GNU General Public License as published by the
>-// Free Software Foundation; either version 3, or (at your option)
>-// any later version.
>-
>-// This library is distributed in the hope that it will be useful,
>-// but WITHOUT ANY WARRANTY; without even the implied warranty of
>-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>-// GNU General Public License for more details.
>-
>-// You should have received a copy of the GNU General Public License along
>-// with this library; see the file COPYING3.  If not see
>-// <http://www.gnu.org/licenses/>.
>-
>-#include <cstdalign>
>-
>-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
>-
>diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
>index e0afc26e458..658a02a4565 100644
>--- a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
>+++ b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
>@@ -1,4 +1,5 @@
>-// { dg-do compile { target c++11 } }
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do preprocess }
>
> // Copyright (C) 2012-2024 Free Software Foundation, Inc.
> //
>@@ -19,6 +20,11 @@
>
> #include <cstdbool>
>
>+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
>+// { dg-warning "deprecated" "" { target c++17_only } 0 }
>+// { dg-error "not a standard header" "" { target c++20 } 0 }
>+
>+#if __cplusplus >= 201103L
> #ifndef __bool_true_false_are_defined
> # error "The header <cstdbool> fails to define a macro named __bool_true_false_are_defined"
> #endif
>@@ -34,3 +40,4 @@
> #ifdef false
> # error "The header <cstdbool> defines a macro named false"
> #endif
>+#endif
>diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
>new file mode 100644
>index 00000000000..a3c0f9a0aec
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
>@@ -0,0 +1,21 @@
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do preprocess { target c++11 } }
>+// { dg-bogus "deprecated" "C++17 deprecated <cstdbool> but not <stdbool.h>" }
>+
>+#include <stdbool.h>
>+
>+#ifndef __bool_true_false_are_defined
>+# error "The header <stdbool.h> fails to define a macro named __bool_true_false_are_defined"
>+#endif
>+
>+#ifdef bool
>+# error "The header <stdbool.h> defines a macro named bool"
>+#endif
>+
>+#ifdef true
>+# error "The header <stdbool.h> defines a macro named true"
>+#endif
>+
>+#ifdef false
>+# error "The header <stdbool.h> defines a macro named false"
>+#endif
>diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
>deleted file mode 100644
>index 5b8c5688877..00000000000
>--- a/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
>+++ /dev/null
>@@ -1,26 +0,0 @@
>-// { dg-options "-std=gnu++98" }
>-// { dg-do compile { target c++98_only } }
>-
>-// Copyright (C) 2007-2024 Free Software Foundation, Inc.
>-//
>-// This file is part of the GNU ISO C++ Library.  This library is free
>-// software; you can redistribute it and/or modify it under the
>-// terms of the GNU General Public License as published by the
>-// Free Software Foundation; either version 3, or (at your option)
>-// any later version.
>-
>-// This library is distributed in the hope that it will be useful,
>-// but WITHOUT ANY WARRANTY; without even the implied warranty of
>-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>-// GNU General Public License for more details.
>-
>-// You should have received a copy of the GNU General Public License along
>-// with this library; see the file COPYING3.  If not see
>-// <http://www.gnu.org/licenses/>.
>-
>-#include <cstdbool>
>-
>-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
>-
>-
>-
>diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
>new file mode 100644
>index 00000000000..d6c33781ae5
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
>@@ -0,0 +1,10 @@
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do compile }
>+
>+#include <ccomplex>
>+
>+std::complex<double> d;
>+
>+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
>+// { dg-warning "deprecated" "" { target c++17_only } 0 }
>+// { dg-error "not a standard header" "" { target c++20 } 0 }
>diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
>new file mode 100644
>index 00000000000..318b78ee89e
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
>@@ -0,0 +1,10 @@
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do compile }
>+// { dg-bogus "deprecated" "C++17 deprecated <ccomplex> but not <complex.h>" }
>+
>+#include <complex.h>
>+
>+#if __cplusplus < 201103L
>+# undef complex
>+#endif
>+std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
>diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
>deleted file mode 100644
>index 16c623b25b0..00000000000
>--- a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
>+++ /dev/null
>@@ -1,26 +0,0 @@
>-// { dg-options "-std=gnu++98" }
>-// { dg-do compile { target c++98_only } }
>-
>-// Copyright (C) 2007-2024 Free Software Foundation, Inc.
>-//
>-// This file is part of the GNU ISO C++ Library.  This library is free
>-// software; you can redistribute it and/or modify it under the
>-// terms of the GNU General Public License as published by the
>-// Free Software Foundation; either version 3, or (at your option)
>-// any later version.
>-
>-// This library is distributed in the hope that it will be useful,
>-// but WITHOUT ANY WARRANTY; without even the implied warranty of
>-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>-// GNU General Public License for more details.
>-
>-// You should have received a copy of the GNU General Public License along
>-// with this library; see the file COPYING3.  If not see
>-// <http://www.gnu.org/licenses/>.
>-
>-#include <ccomplex>
>-
>-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
>-
>-
>-
>diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
>index a2c4a55c89b..ef2bbd0e20a 100644
>--- a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
>+++ b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
>@@ -15,8 +15,13 @@
> // with this library; see the file COPYING3.  If not see
> // <http://www.gnu.org/licenses/>.
>
>-// { dg-do compile { target c++11 } }
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do compile }
>
> #include <ctgmath>
>
>-std::complex<double> d;
>+std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
>+
>+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
>+// { dg-warning "deprecated" "" { target c++17_only } 0 }
>+// { dg-error "not a standard header" "" { target c++20 } 0 }
>diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
>new file mode 100644
>index 00000000000..fd6847bff4f
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
>@@ -0,0 +1,10 @@
>+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
>+// { dg-do compile }
>+// { dg-bogus "deprecated" "C++17 deprecated <ctgmath> but not <tgmath.h>" }
>+
>+#include <tgmath.h>
>+
>+#if __cplusplus < 201103L
>+# undef complex
>+#endif
>+std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
>diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
>deleted file mode 100644
>index d693c8b23ed..00000000000
>--- a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
>+++ /dev/null
>@@ -1,26 +0,0 @@
>-// { dg-options "-std=gnu++98" }
>-// { dg-do compile { target c++98_only } }
>-
>-// Copyright (C) 2007-2024 Free Software Foundation, Inc.
>-//
>-// This file is part of the GNU ISO C++ Library.  This library is free
>-// software; you can redistribute it and/or modify it under the
>-// terms of the GNU General Public License as published by the
>-// Free Software Foundation; either version 3, or (at your option)
>-// any later version.
>-
>-// This library is distributed in the hope that it will be useful,
>-// but WITHOUT ANY WARRANTY; without even the implied warranty of
>-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>-// GNU General Public License for more details.
>-
>-// You should have received a copy of the GNU General Public License along
>-// with this library; see the file COPYING3.  If not see
>-// <http://www.gnu.org/licenses/>.
>-
>-#include <ctgmath>
>-
>-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
>-
>-
>-
>diff --git a/libstdc++-v3/testsuite/27_io/objects/char/1.cc b/libstdc++-v3/testsuite/27_io/objects/char/1.cc
>index 9fc9244baf4..d50b3884702 100644
>--- a/libstdc++-v3/testsuite/27_io/objects/char/1.cc
>+++ b/libstdc++-v3/testsuite/27_io/objects/char/1.cc
>@@ -53,7 +53,6 @@
> #include <cctype>
> #include <cerrno>
> #include <cfloat>
>-#include <ciso646>
> #include <climits>
> #include <clocale>
> #include <cmath>
>diff --git a/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc b/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
>index 23b2168805d..c2f3643b4e5 100644
>--- a/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
>+++ b/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
>@@ -53,7 +53,6 @@
> #include <cctype>
> #include <cerrno>
> #include <cfloat>
>-#include <ciso646>
> #include <climits>
> #include <clocale>
> #include <cmath>
>-- 
>2.47.0
>
Jonathan Wakely Nov. 1, 2024, 9:02 p.m. UTC | #3
On 01/11/24 20:56 +0000, Jonathan Wakely wrote:
>On 31/10/24 20:09 +0000, Jonathan Wakely wrote:
>>Tested x86_64-linux. Is the g++ test change OK?
>>
>>Also available for review at:
>>https://forge.sourceware.org/gcc/gcc-TEST/pulls/4
>>
>>-- >8 --
>>
>>These headers make no sense for C++ programs, because they either define
>>different content to the corresponding <xxx.h> C header, or define
>>nothing at all in namespace std. They were all deprecated in C++17, so
>>add deprecation warnings to them, which can be disabled with
>>-Wno-deprecated. For C++20 and later these headers are no longer in the
>>standard at all, so compiling with _GLIBCXX_USE_DEPRECATED defined to 0
>>will give an error when they are included.
>>
>>Because #warning is non-standard before C++23 we need to use pragmas to
>>ignore -Wc++23-extensions for the -Wsystem-headers -pedantic case.
>>
>>One g++ test needs adjustment because it includes <ciso646>, but that
>>can be made conditional on the __cplusplus value without any reduction
>>in test coverage.
>>
>>For the library tests, consolidate the std_c++0x_neg.cc XFAIL tests into
>>the macros.cc test, using dg-error with a { target c++98_only }
>>selector. This avoids having two separate test files, one for C++98 and
>>one for everything later. Also add tests for the <xxx.h> headers to
>>ensure that they behave as expected and don't give deprecated warnings.
>>
>>libstdc++-v3/ChangeLog:
>>
>>	* doc/xml/manual/evolution.xml: Document deprecations.
>>	* doc/html/*: Regenerate.
>>	* include/c_compatibility/complex.h (_GLIBCXX_COMPLEX_H): Move
>>	include guard to start of file. Include <complex> directly
>>	instead of <ccomplex>.
>>	* include/c_compatibility/tgmath.h: Include <cmath> and
>>	<complex> directly, instead of <ctgmath>.
>>	* include/c_global/ccomplex: Add deprecated #warning for C++17
>>	and #error for C++20 if _GLIBCXX_USE_DEPRECATED == 0.
>>	* include/c_global/ciso646: Likewise.
>>	* include/c_global/cstdalign: Likewise.
>>	* include/c_global/cstdbool: Likewise.
>>	* include/c_global/ctgmath: Likewise.
>>	* include/c_std/ciso646: Likewise.
>>	* include/precompiled/stdc++.h: Do not include ccomplex,
>>	ciso646, cstdalign, cstdbool, or ctgmath in C++17 and later.
>>	* testsuite/18_support/headers/cstdalign/macros.cc: Check for
>>	warnings and errors for unsupported dialects.
>>	* testsuite/18_support/headers/cstdbool/macros.cc: Likewise.
>>	* testsuite/26_numerics/headers/ctgmath/complex.cc: Likewise.
>>	* testsuite/27_io/objects/char/1.cc: Do not include <ciso646>.
>>	* testsuite/27_io/objects/wchar_t/1.cc: Likewise.
>>	* testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc: Removed.
>>	* testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc: Removed.
>>	* testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc: Removed.
>>	* testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc: Removed.
>>	* testsuite/18_support/headers/ciso646/macros.cc: New test.
>>	* testsuite/18_support/headers/ciso646/macros.h.cc: New test.
>>	* testsuite/18_support/headers/cstdbool/macros.h.cc: New test.
>>	* testsuite/26_numerics/headers/ccomplex/complex.cc: New test.
>>	* testsuite/26_numerics/headers/ccomplex/complex.h.cc: New test.
>>	* testsuite/26_numerics/headers/ctgmath/complex.h.cc: New test.
>>
>>gcc/testsuite/ChangeLog:
>>
>>	* g++.old-deja/g++.other/headers1.C: Do not include ciso646 for
>>	C++17 and later.
>>---
>>.../g++.old-deja/g++.other/headers1.C         |  2 +
>>libstdc++-v3/doc/html/manual/api.html         |  8 +++
>>libstdc++-v3/doc/xml/manual/evolution.xml     | 10 ++++
>>.../include/c_compatibility/complex.h         | 10 ++--
>>libstdc++-v3/include/c_compatibility/tgmath.h | 11 ++--
>>libstdc++-v3/include/c_global/ccomplex        |  9 ++++
>>libstdc++-v3/include/c_global/ciso646         |  9 ++++
>>libstdc++-v3/include/c_global/cstdalign       |  8 +++
>>libstdc++-v3/include/c_global/cstdbool        |  8 +++
>>libstdc++-v3/include/c_global/ctgmath         | 14 +++--
>>libstdc++-v3/include/c_std/ciso646            | 10 ++++
>>libstdc++-v3/include/precompiled/stdc++.h     | 13 +++--
>>.../18_support/headers/ciso646/macros.cc      | 51 +++++++++++++++++++
>>.../18_support/headers/ciso646/macros.h.cc    | 49 ++++++++++++++++++
>>.../18_support/headers/cstdalign/macros.cc    | 10 +++-
>>.../18_support/headers/cstdalign/macros.h.cc  | 25 +++++++++
>>.../headers/cstdalign/std_c++0x_neg.cc        | 24 ---------
>>.../18_support/headers/cstdbool/macros.cc     |  9 +++-
>>.../18_support/headers/cstdbool/macros.h.cc   | 21 ++++++++
>>.../headers/cstdbool/std_c++0x_neg.cc         | 26 ----------
>>.../26_numerics/headers/ccomplex/complex.cc   | 10 ++++
>>.../26_numerics/headers/ccomplex/complex.h.cc | 10 ++++
>>.../headers/ccomplex/std_c++0x_neg.cc         | 26 ----------
>>.../26_numerics/headers/ctgmath/complex.cc    |  9 +++-
>>.../26_numerics/headers/ctgmath/complex.h.cc  | 10 ++++
>>.../headers/ctgmath/std_c++0x_neg.cc          | 26 ----------
>>.../testsuite/27_io/objects/char/1.cc         |  1 -
>>.../testsuite/27_io/objects/wchar_t/1.cc      |  1 -
>>28 files changed, 294 insertions(+), 126 deletions(-)
>>create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
>>create mode 100644 libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
>>create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
>>delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
>>create mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
>>delete mode 100644 libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
>>create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
>>create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
>>delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
>>create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
>>delete mode 100644 libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
>>
>>diff --git a/gcc/testsuite/g++.old-deja/g++.other/headers1.C b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
>>index 5d37e94082f..90a1a7dc8f9 100644
>>--- a/gcc/testsuite/g++.old-deja/g++.other/headers1.C
>>+++ b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
>>@@ -12,7 +12,9 @@
>>#include <cctype>
>>#include <cerrno>
>>#include <cfloat>
>>+#if __cplusplus < 201703L
>>#include <ciso646>
>>+#endif
>>#include <climits>
>>#include <clocale>
>>#include <cmath>
>>diff --git a/libstdc++-v3/doc/html/manual/api.html b/libstdc++-v3/doc/html/manual/api.html
>>index 799f6eae2a2..2ccfc07b83e 100644
>>--- a/libstdc++-v3/doc/html/manual/api.html
>>+++ b/libstdc++-v3/doc/html/manual/api.html
>>@@ -498,4 +498,12 @@ to be used with <code class="code">std::basic_istream</code>.
>>  longer allowed in C++20 mode.
>></p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_151"></a><code class="constant">15</code></h3></div></div></div><p>
>>Enabled debug assertions by default for unoptimized builds.
>>+</p><p>
>>+Added warnings when including the headers that were deprecated in C++17
>>+and removed in C++20:
>>+<code class="filename">&lt;ccomplex&gt;</code>,
>>+<code class="filename">&lt;ciso646&gt;</code>,
>>+<code class="filename">&lt;cstdalign&gt;</code>,
>>+<code class="filename">&lt;cstdbool&gt;</code>, and
>>+<code class="filename">&lt;ctgmath&gt;</code>.
>></p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="abi.html">Prev</a>??</td><td width="20%" align="center"><a accesskey="u" href="appendix_porting.html">Up</a></td><td width="40%" align="right">??<a accesskey="n" href="backwards.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ABI Policy and Guidelines??</td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top">??Backwards Compatibility</td></tr></table></div></body></html>
>>\ No newline at end of file
>>diff --git a/libstdc++-v3/doc/xml/manual/evolution.xml b/libstdc++-v3/doc/xml/manual/evolution.xml
>>index 75cf948a4a2..6b134de0e71 100644
>>--- a/libstdc++-v3/doc/xml/manual/evolution.xml
>>+++ b/libstdc++-v3/doc/xml/manual/evolution.xml
>>@@ -1135,6 +1135,16 @@ to be used with <code>std::basic_istream</code>.
>>Enabled debug assertions by default for unoptimized builds.
>></para>
>>
>>+<para>
>>+Added warnings when including the headers that were deprecated in C++17
>>+and removed in C++20:
>>+<filename class="headerfile">&lt;ccomplex&gt;</filename>,
>>+<filename class="headerfile">&lt;ciso646&gt;</filename>,
>>+<filename class="headerfile">&lt;cstdalign&gt;</filename>,
>>+<filename class="headerfile">&lt;cstdbool&gt;</filename>, and
>>+<filename class="headerfile">&lt;ctgmath&gt;</filename>.
>>+</para>
>>+
>></section>
>>
>></section>
>>diff --git a/libstdc++-v3/include/c_compatibility/complex.h b/libstdc++-v3/include/c_compatibility/complex.h
>>index 605d1f30e06..461ff2117b1 100644
>>--- a/libstdc++-v3/include/c_compatibility/complex.h
>>+++ b/libstdc++-v3/include/c_compatibility/complex.h
>>@@ -26,10 +26,15 @@
>> *  This is a Standard C++ Library header.
>> */
>>
>>+#ifndef _GLIBCXX_COMPLEX_H
>>+#define _GLIBCXX_COMPLEX_H 1
>>+
>>#include <bits/c++config.h>
>>
>>#if __cplusplus >= 201103L
>>-# include <ccomplex>
>>+extern "C++" {
>>+#include <complex>
>>+}
>>#endif
>>
>>#if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
>>@@ -42,7 +47,4 @@
>># endif
>>#endif
>>
>>-#ifndef _GLIBCXX_COMPLEX_H
>>-#define _GLIBCXX_COMPLEX_H 1
>>-
>>#endif
>>diff --git a/libstdc++-v3/include/c_compatibility/tgmath.h b/libstdc++-v3/include/c_compatibility/tgmath.h
>>index aadddd91b60..6bf6727a15c 100644
>>--- a/libstdc++-v3/include/c_compatibility/tgmath.h
>>+++ b/libstdc++-v3/include/c_compatibility/tgmath.h
>>@@ -32,11 +32,12 @@
>>#include <bits/c++config.h>
>>
>>#if __cplusplus >= 201103L
>>-# include <ctgmath>
>>-#else
>>-# if _GLIBCXX_HAVE_TGMATH_H
>>-#  include_next <tgmath.h>
>>-# endif
>>+# include <cmath>
>>+extern "C++" {
>>+# include <complex>
>>+}
>>+#elif _GLIBCXX_HAVE_TGMATH_H
>>+# include_next <tgmath.h>
>>#endif
>>
>>#endif
>>diff --git a/libstdc++-v3/include/c_global/ccomplex b/libstdc++-v3/include/c_global/ccomplex
>>index ee1166aaecb..b0e30fa67eb 100644
>>--- a/libstdc++-v3/include/c_global/ccomplex
>>+++ b/libstdc++-v3/include/c_global/ccomplex
>>@@ -41,4 +41,13 @@ extern "C++" {
>>#include <complex>
>>}
>>
>>+#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
>>+#  error "<ccomplex> is not a standard header in C++20, use <complex.h>"
>>+#elif __cplusplus >= 201703L && defined __DEPRECATED
>>+#  pragma GCC diagnostic push
>>+#  pragma GCC diagnostic ignored "-Wc++23-extensions"
>>+#  warning "<ccomplex> is deprecated in C++17, use <complex.h>"
>
>I'm not sure whether we should suggest <complex.h> or <complex> here.
>
>It's hard to know what users might have intended when including
><ccomplex>. I suppose we should suggest <complex>, since that's what
>they got for <ccomplex> in C++11 and C++14.

Maybe the best thing to do is not make any suggestion, and write more
detailed information in https://gcc.gnu.org/gcc-15/porting_to.html
diff mbox series

Patch

diff --git a/gcc/testsuite/g++.old-deja/g++.other/headers1.C b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
index 5d37e94082f..90a1a7dc8f9 100644
--- a/gcc/testsuite/g++.old-deja/g++.other/headers1.C
+++ b/gcc/testsuite/g++.old-deja/g++.other/headers1.C
@@ -12,7 +12,9 @@ 
 #include <cctype>
 #include <cerrno>
 #include <cfloat>
+#if __cplusplus < 201703L
 #include <ciso646>
+#endif
 #include <climits>
 #include <clocale>
 #include <cmath>
diff --git a/libstdc++-v3/doc/html/manual/api.html b/libstdc++-v3/doc/html/manual/api.html
index 799f6eae2a2..2ccfc07b83e 100644
--- a/libstdc++-v3/doc/html/manual/api.html
+++ b/libstdc++-v3/doc/html/manual/api.html
@@ -498,4 +498,12 @@  to be used with <code class="code">std::basic_istream</code>.
   longer allowed in C++20 mode.
 </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="api.rel_151"></a><code class="constant">15</code></h3></div></div></div><p>
 Enabled debug assertions by default for unoptimized builds.
+</p><p>
+Added warnings when including the headers that were deprecated in C++17
+and removed in C++20:
+<code class="filename">&lt;ccomplex&gt;</code>,
+<code class="filename">&lt;ciso646&gt;</code>,
+<code class="filename">&lt;cstdalign&gt;</code>,
+<code class="filename">&lt;cstdbool&gt;</code>, and
+<code class="filename">&lt;ctgmath&gt;</code>.
 </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="abi.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="appendix_porting.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="backwards.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ABI Policy and Guidelines </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Backwards Compatibility</td></tr></table></div></body></html>
\ No newline at end of file
diff --git a/libstdc++-v3/doc/xml/manual/evolution.xml b/libstdc++-v3/doc/xml/manual/evolution.xml
index 75cf948a4a2..6b134de0e71 100644
--- a/libstdc++-v3/doc/xml/manual/evolution.xml
+++ b/libstdc++-v3/doc/xml/manual/evolution.xml
@@ -1135,6 +1135,16 @@  to be used with <code>std::basic_istream</code>.
 Enabled debug assertions by default for unoptimized builds.
 </para>
 
+<para>
+Added warnings when including the headers that were deprecated in C++17
+and removed in C++20:
+<filename class="headerfile">&lt;ccomplex&gt;</filename>,
+<filename class="headerfile">&lt;ciso646&gt;</filename>,
+<filename class="headerfile">&lt;cstdalign&gt;</filename>,
+<filename class="headerfile">&lt;cstdbool&gt;</filename>, and
+<filename class="headerfile">&lt;ctgmath&gt;</filename>.
+</para>
+
 </section>
 
 </section>
diff --git a/libstdc++-v3/include/c_compatibility/complex.h b/libstdc++-v3/include/c_compatibility/complex.h
index 605d1f30e06..461ff2117b1 100644
--- a/libstdc++-v3/include/c_compatibility/complex.h
+++ b/libstdc++-v3/include/c_compatibility/complex.h
@@ -26,10 +26,15 @@ 
  *  This is a Standard C++ Library header.
  */
 
+#ifndef _GLIBCXX_COMPLEX_H
+#define _GLIBCXX_COMPLEX_H 1
+
 #include <bits/c++config.h>
 
 #if __cplusplus >= 201103L
-# include <ccomplex>
+extern "C++" {
+#include <complex>
+}
 #endif
 
 #if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
@@ -42,7 +47,4 @@ 
 # endif
 #endif
 
-#ifndef _GLIBCXX_COMPLEX_H
-#define _GLIBCXX_COMPLEX_H 1
-
 #endif
diff --git a/libstdc++-v3/include/c_compatibility/tgmath.h b/libstdc++-v3/include/c_compatibility/tgmath.h
index aadddd91b60..6bf6727a15c 100644
--- a/libstdc++-v3/include/c_compatibility/tgmath.h
+++ b/libstdc++-v3/include/c_compatibility/tgmath.h
@@ -32,11 +32,12 @@ 
 #include <bits/c++config.h>
 
 #if __cplusplus >= 201103L
-# include <ctgmath>
-#else
-# if _GLIBCXX_HAVE_TGMATH_H
-#  include_next <tgmath.h>
-# endif
+# include <cmath>
+extern "C++" {
+# include <complex>
+}
+#elif _GLIBCXX_HAVE_TGMATH_H
+# include_next <tgmath.h>
 #endif
 
 #endif
diff --git a/libstdc++-v3/include/c_global/ccomplex b/libstdc++-v3/include/c_global/ccomplex
index ee1166aaecb..b0e30fa67eb 100644
--- a/libstdc++-v3/include/c_global/ccomplex
+++ b/libstdc++-v3/include/c_global/ccomplex
@@ -41,4 +41,13 @@  extern "C++" {
 #include <complex>
 }
 
+#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
+#  error "<ccomplex> is not a standard header in C++20, use <complex.h>"
+#elif __cplusplus >= 201703L && defined __DEPRECATED
+#  pragma GCC diagnostic push
+#  pragma GCC diagnostic ignored "-Wc++23-extensions"
+#  warning "<ccomplex> is deprecated in C++17, use <complex.h>"
+#  pragma GCC diagnostic pop
+#endif
+
 #endif
diff --git a/libstdc++-v3/include/c_global/ciso646 b/libstdc++-v3/include/c_global/ciso646
index 6e26f9be12e..ed1fcf6f14e 100644
--- a/libstdc++-v3/include/c_global/ciso646
+++ b/libstdc++-v3/include/c_global/ciso646
@@ -38,4 +38,13 @@ 
 
 #include <bits/c++config.h>
 
+#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
+#  error "<ciso646> is not a standard header in C++20, use <iso646.h> or <version>"
+#elif __cplusplus >= 201703L && defined __DEPRECATED
+#  pragma GCC diagnostic push
+#  pragma GCC diagnostic ignored "-Wc++23-extensions"
+#  warning "<ciso646> is deprecated in C++17, use <iso646.h> or <version>"
+#  pragma GCC diagnostic pop
+#endif
+
 #endif
diff --git a/libstdc++-v3/include/c_global/cstdalign b/libstdc++-v3/include/c_global/cstdalign
index 4f610588425..f7bbbad82a0 100644
--- a/libstdc++-v3/include/c_global/cstdalign
+++ b/libstdc++-v3/include/c_global/cstdalign
@@ -40,6 +40,14 @@ 
 #  if _GLIBCXX_HAVE_STDALIGN_H
 #    include <stdalign.h>
 #  endif
+#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
+#    error "<cstdalign> is not a standard header in C++20, use <stdalign.h>"
+#  elif __cplusplus >= 201703L && defined __DEPRECATED
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wc++23-extensions"
+#    warning "<cstdalign> is deprecated in C++17, use <stdalign.h>"
+#    pragma GCC diagnostic pop
+#  endif
 #endif
 
 #endif
diff --git a/libstdc++-v3/include/c_global/cstdbool b/libstdc++-v3/include/c_global/cstdbool
index 8d2e75df33f..27be50ff510 100644
--- a/libstdc++-v3/include/c_global/cstdbool
+++ b/libstdc++-v3/include/c_global/cstdbool
@@ -40,6 +40,14 @@ 
 #  if _GLIBCXX_HAVE_STDBOOL_H
 #    include <stdbool.h>
 #  endif
+#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
+#    error "<cstdbool> is not a standard header in C++20, use <stdbool.h>"
+#  elif __cplusplus >= 201703L && defined __DEPRECATED
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wc++23-extensions"
+#    warning "<cstdbool> is deprecated in C++17, use <stdbool.h>"
+#    pragma GCC diagnostic pop
+#  endif
 #endif
 
 #endif
diff --git a/libstdc++-v3/include/c_global/ctgmath b/libstdc++-v3/include/c_global/ctgmath
index 79c1a029f41..5824a20c7c0 100644
--- a/libstdc++-v3/include/c_global/ctgmath
+++ b/libstdc++-v3/include/c_global/ctgmath
@@ -26,13 +26,13 @@ 
  *  This is a Standard C++ Library header.
  */
 
+#ifndef _GLIBCXX_CTGMATH
+#define _GLIBCXX_CTGMATH 1
+
 #ifdef _GLIBCXX_SYSHDR
 #pragma GCC system_header
 #endif
 
-#ifndef _GLIBCXX_CTGMATH
-#define _GLIBCXX_CTGMATH 1
-
 #if __cplusplus < 201103L
 #  include <bits/c++0x_warning.h>
 #else
@@ -40,6 +40,14 @@ 
 extern "C++" {
 #  include <complex>
 }
+#  if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
+#    error "<ctgmath> is not a standard header in C++20, use <tgmath.h>"
+#  elif __cplusplus >= 201703L && defined __DEPRECATED
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wc++23-extensions"
+#    warning "<ctgmath> is deprecated in C++17, use <tgmath.h>"
+#    pragma GCC diagnostic pop
+#  endif
 #endif
 
 #endif
diff --git a/libstdc++-v3/include/c_std/ciso646 b/libstdc++-v3/include/c_std/ciso646
index 7971f0d0c31..ac9801aef2b 100644
--- a/libstdc++-v3/include/c_std/ciso646
+++ b/libstdc++-v3/include/c_std/ciso646
@@ -37,4 +37,14 @@ 
 #endif
 
 #include <bits/c++config.h>
+
+#if __cplusplus >= 202002L && ! _GLIBCXX_USE_DEPRECATED
+#  error "<ciso646> is not a standard header in C++20, use <iso646.h> or <version>"
+#elif __cplusplus >= 201703L && defined __DEPRECATED
+#  pragma GCC diagnostic push
+#  pragma GCC diagnostic ignored "-Wc++23-extensions"
+#  warning "<ciso646> is deprecated in C++17, use <iso646.h> or <version>"
+#  pragma GCC diagnostic pop
+#endif
+
 #endif
diff --git a/libstdc++-v3/include/precompiled/stdc++.h b/libstdc++-v3/include/precompiled/stdc++.h
index 3eef20d1645..89917106bac 100644
--- a/libstdc++-v3/include/precompiled/stdc++.h
+++ b/libstdc++-v3/include/precompiled/stdc++.h
@@ -34,7 +34,6 @@ 
 #endif
 #include <cctype>
 #include <cfloat>
-#include <ciso646>
 #include <climits>
 #include <csetjmp>
 #include <cstdarg>
@@ -43,6 +42,9 @@ 
 
 #if __cplusplus >= 201103L
 #include <cstdint>
+#if __cplusplus < 201703L
+#include <ciso646>
+#endif
 #endif
 
 // C++
@@ -108,7 +110,6 @@ 
 #include <cctype>
 #include <cerrno>
 #include <cfloat>
-#include <ciso646>
 #include <climits>
 #include <clocale>
 #include <cmath>
@@ -124,14 +125,16 @@ 
 #include <cwctype>
 
 #if __cplusplus >= 201103L
-#include <ccomplex>
 #include <cfenv>
 #include <cinttypes>
+#include <cstdint>
+#include <cuchar>
+#if __cplusplus < 201703L
+#include <ccomplex>
 #include <cstdalign>
 #include <cstdbool>
-#include <cstdint>
 #include <ctgmath>
-#include <cuchar>
+#endif
 #endif
 
 // C++
diff --git a/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
new file mode 100644
index 00000000000..ab3a041de06
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.cc
@@ -0,0 +1,51 @@ 
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated -fno-operator-names" }
+// { dg-do preprocess }
+
+#include <ciso646>
+
+// { dg-warning "deprecated" "" { target c++17_only } 0 }
+// { dg-error "not a standard header" "" { target c++20 } 0 }
+
+#ifdef and
+# error "The header <ciso646> defines a macro named and"
+#endif
+
+#ifdef and_eq
+# error "The header <ciso646> defines a macro named and_eq"
+#endif
+
+#ifdef bitand
+# error "The header <ciso646> defines a macro named bitand"
+#endif
+
+#ifdef bitor
+# error "The header <ciso646> defines a macro named bitor"
+#endif
+
+#ifdef compl
+# error "The header <ciso646> defines a macro named compl"
+#endif
+
+#ifdef not
+# error "The header <ciso646> defines a macro named not"
+#endif
+
+#ifdef not_eq
+# error "The header <ciso646> defines a macro named not_eq"
+#endif
+
+#ifdef or
+# error "The header <ciso646> defines a macro named or"
+#endif
+
+#ifdef or_eq
+# error "The header <ciso646> defines a macro named or_eq"
+#endif
+
+#ifdef xor
+# error "The header <ciso646> defines a macro named xor"
+#endif
+
+#ifdef xor_eq
+# error "The header <ciso646> defines a macro named xor_eq"
+#endif
diff --git a/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
new file mode 100644
index 00000000000..a70c18de918
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/headers/ciso646/macros.h.cc
@@ -0,0 +1,49 @@ 
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated -fno-operator-names" }
+// { dg-do preprocess }
+// { dg-bogus "deprecated" "C++17 deprecated <ciso646> but not <iso646.h>" }
+
+#include <iso646.h>
+
+#ifdef and
+# error "The header <iso646.h> defines a macro named and"
+#endif
+
+#ifdef and_eq
+# error "The header <iso646.h> defines a macro named and_eq"
+#endif
+
+#ifdef bitand
+# error "The header <iso646.h> defines a macro named bitand"
+#endif
+
+#ifdef bitor
+# error "The header <iso646.h> defines a macro named bitor"
+#endif
+
+#ifdef compl
+# error "The header <iso646.h> defines a macro named compl"
+#endif
+
+#ifdef not
+# error "The header <iso646.h> defines a macro named not"
+#endif
+
+#ifdef not_eq
+# error "The header <iso646.h> defines a macro named not_eq"
+#endif
+
+#ifdef or
+# error "The header <iso646.h> defines a macro named or"
+#endif
+
+#ifdef or_eq
+# error "The header <iso646.h> defines a macro named or_eq"
+#endif
+
+#ifdef xor
+# error "The header <iso646.h> defines a macro named xor"
+#endif
+
+#ifdef xor_eq
+# error "The header <iso646.h> defines a macro named xor_eq"
+#endif
diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
index c50c921cd59..793cd26dfa8 100644
--- a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
+++ b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.cc
@@ -1,8 +1,13 @@ 
-// { dg-options "-D_GLIBCXX_USE_DEPRECATED=1 -Wno-deprecated" }
-// { dg-do preprocess { target c++11 } }
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do preprocess }
 
 #include <cstdalign>
 
+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
+// { dg-warning "deprecated" "" { target c++17_only } 0 }
+// { dg-error "not a standard header" "" { target c++20 } 0 }
+
+#if __cplusplus >= 201103L
 #ifndef __alignas_is_defined
 # error "The header <cstdalign> fails to define a macro named  __alignas_is_defined"
 #elif __alignas_is_defined != 1
@@ -22,3 +27,4 @@ 
 #ifdef alignof
 # error "The header <cstdalign> defines a macro named alignof"
 #endif
+#endif
diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
new file mode 100644
index 00000000000..78f41ae02e8
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/headers/cstdalign/macros.h.cc
@@ -0,0 +1,25 @@ 
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do preprocess { target c++11 } }
+// { dg-bogus "deprecated" "C++17 deprecated <cstdalign> but not <stdalign.h>" }
+
+#include <stdalign.h>
+
+#ifndef __alignas_is_defined
+# error "The header <stdalign.h> fails to define a macro named  __alignas_is_defined"
+#elif __alignas_is_defined != 1
+# error "__alignas_is_defined is not defined to 1 in <stdalign.h>"
+#endif
+
+#ifndef __alignof_is_defined
+# error "The header <stdalign.h> fails to define a macro named __alignof_is_defined"
+#elif __alignof_is_defined != 1
+# error "__alignof_is_defined is not defined to 1 in <stdalign.h>"
+#endif
+
+#ifdef alignas
+# error "The header <stdalign.h> defines a macro named alignas"
+#endif
+
+#ifdef alignof
+# error "The header <stdalign.h> defines a macro named alignof"
+#endif
diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc b/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
deleted file mode 100644
index 14694f034e6..00000000000
--- a/libstdc++-v3/testsuite/18_support/headers/cstdalign/std_c++0x_neg.cc
+++ /dev/null
@@ -1,24 +0,0 @@ 
-// { dg-options "-std=gnu++98" }
-// { dg-do compile { target c++98_only } }
-
-// Copyright (C) 2011-2024 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-#include <cstdalign>
-
-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
-
diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
index e0afc26e458..658a02a4565 100644
--- a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
+++ b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.cc
@@ -1,4 +1,5 @@ 
-// { dg-do compile { target c++11 } }
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do preprocess }
 
 // Copyright (C) 2012-2024 Free Software Foundation, Inc.
 //
@@ -19,6 +20,11 @@ 
 
 #include <cstdbool>
 
+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
+// { dg-warning "deprecated" "" { target c++17_only } 0 }
+// { dg-error "not a standard header" "" { target c++20 } 0 }
+
+#if __cplusplus >= 201103L
 #ifndef __bool_true_false_are_defined
 # error "The header <cstdbool> fails to define a macro named __bool_true_false_are_defined"
 #endif
@@ -34,3 +40,4 @@ 
 #ifdef false
 # error "The header <cstdbool> defines a macro named false"
 #endif
+#endif
diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
new file mode 100644
index 00000000000..a3c0f9a0aec
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/headers/cstdbool/macros.h.cc
@@ -0,0 +1,21 @@ 
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do preprocess { target c++11 } }
+// { dg-bogus "deprecated" "C++17 deprecated <cstdbool> but not <stdbool.h>" }
+
+#include <stdbool.h>
+
+#ifndef __bool_true_false_are_defined
+# error "The header <stdbool.h> fails to define a macro named __bool_true_false_are_defined"
+#endif
+
+#ifdef bool
+# error "The header <stdbool.h> defines a macro named bool"
+#endif
+
+#ifdef true
+# error "The header <stdbool.h> defines a macro named true"
+#endif
+
+#ifdef false
+# error "The header <stdbool.h> defines a macro named false"
+#endif
diff --git a/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc b/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
deleted file mode 100644
index 5b8c5688877..00000000000
--- a/libstdc++-v3/testsuite/18_support/headers/cstdbool/std_c++0x_neg.cc
+++ /dev/null
@@ -1,26 +0,0 @@ 
-// { dg-options "-std=gnu++98" }
-// { dg-do compile { target c++98_only } }
-
-// Copyright (C) 2007-2024 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-#include <cstdbool>
-
-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
-
-
-
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
new file mode 100644
index 00000000000..d6c33781ae5
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.cc
@@ -0,0 +1,10 @@ 
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do compile }
+
+#include <ccomplex>
+
+std::complex<double> d;
+
+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
+// { dg-warning "deprecated" "" { target c++17_only } 0 }
+// { dg-error "not a standard header" "" { target c++20 } 0 }
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
new file mode 100644
index 00000000000..318b78ee89e
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/complex.h.cc
@@ -0,0 +1,10 @@ 
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do compile }
+// { dg-bogus "deprecated" "C++17 deprecated <ccomplex> but not <complex.h>" }
+
+#include <complex.h>
+
+#if __cplusplus < 201103L
+# undef complex
+#endif
+std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc b/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
deleted file mode 100644
index 16c623b25b0..00000000000
--- a/libstdc++-v3/testsuite/26_numerics/headers/ccomplex/std_c++0x_neg.cc
+++ /dev/null
@@ -1,26 +0,0 @@ 
-// { dg-options "-std=gnu++98" }
-// { dg-do compile { target c++98_only } }
-
-// Copyright (C) 2007-2024 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-#include <ccomplex>
-
-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
-
-
-
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
index a2c4a55c89b..ef2bbd0e20a 100644
--- a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
+++ b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.cc
@@ -15,8 +15,13 @@ 
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-do compile { target c++11 } }
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do compile }
 
 #include <ctgmath>
 
-std::complex<double> d;
+std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
+
+// { dg-error "ISO C.. 2011" "" { target c++98_only } 0 }
+// { dg-warning "deprecated" "" { target c++17_only } 0 }
+// { dg-error "not a standard header" "" { target c++20 } 0 }
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
new file mode 100644
index 00000000000..fd6847bff4f
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/complex.h.cc
@@ -0,0 +1,10 @@ 
+// { dg-options "-D_GLIBCXX_USE_DEPRECATED=0 -Wdeprecated" }
+// { dg-do compile }
+// { dg-bogus "deprecated" "C++17 deprecated <ctgmath> but not <tgmath.h>" }
+
+#include <tgmath.h>
+
+#if __cplusplus < 201103L
+# undef complex
+#endif
+std::complex<double> d; // { dg-error "does not name a template" "" { target c++98_only } 0 }
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc b/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
deleted file mode 100644
index d693c8b23ed..00000000000
--- a/libstdc++-v3/testsuite/26_numerics/headers/ctgmath/std_c++0x_neg.cc
+++ /dev/null
@@ -1,26 +0,0 @@ 
-// { dg-options "-std=gnu++98" }
-// { dg-do compile { target c++98_only } }
-
-// Copyright (C) 2007-2024 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-#include <ctgmath>
-
-// { dg-error "ISO C.. 2011" "" { target *-*-* } 32 }
-
-
-
diff --git a/libstdc++-v3/testsuite/27_io/objects/char/1.cc b/libstdc++-v3/testsuite/27_io/objects/char/1.cc
index 9fc9244baf4..d50b3884702 100644
--- a/libstdc++-v3/testsuite/27_io/objects/char/1.cc
+++ b/libstdc++-v3/testsuite/27_io/objects/char/1.cc
@@ -53,7 +53,6 @@ 
 #include <cctype>
 #include <cerrno>
 #include <cfloat>
-#include <ciso646>
 #include <climits>
 #include <clocale>
 #include <cmath>
diff --git a/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc b/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
index 23b2168805d..c2f3643b4e5 100644
--- a/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
+++ b/libstdc++-v3/testsuite/27_io/objects/wchar_t/1.cc
@@ -53,7 +53,6 @@ 
 #include <cctype>
 #include <cerrno>
 #include <cfloat>
-#include <ciso646>
 #include <climits>
 #include <clocale>
 #include <cmath>