[gcc/devel/c++-coroutines] libstdc++: Deprecate the --enable-cheaders=c_std configuration
Iain D Sandoe
iains@gcc.gnu.org
Thu Aug 13 20:08:20 GMT 2020
https://gcc.gnu.org/g:55484a0f816ef9ad7e13fb1057751223ed8471d8
commit 55484a0f816ef9ad7e13fb1057751223ed8471d8
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Aug 13 16:33:28 2020 +0100
libstdc++: Deprecate the --enable-cheaders=c_std configuration
These headers do not offer any tangible benefit compared to the default
c_global version. They are not actively maintained meaning that they
have bugs which have already been fixed for the c_global headers.
This change adds a warning if they are used, and requires a new
--enable-cheaders-obsolete option to allow their use. Unless we receive
reports from users who rely on the c_std headers they should be removed
at some point in future.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_ENABLE_CHEADERS): Warn if the c_std
option is used and fail unless --enable-cheaders-obsolete is
also used.
* configure: Regenerate.
Diff:
---
libstdc++-v3/acinclude.m4 | 16 ++++++++++++++--
libstdc++-v3/configure | 46 ++++++++++++++++++++++++++++++++++++----------
2 files changed, 50 insertions(+), 12 deletions(-)
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 26cf2197549..133125ec4fa 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -2377,12 +2377,24 @@ dnl
dnl --enable-cheaders= [does stuff].
dnl --disable-cheaders [does not do anything, really].
dnl + Usage: GLIBCXX_ENABLE_CHEADERS[(DEFAULT)]
-dnl Where DEFAULT is either 'c' or 'c_std' or 'c_global'.
+dnl Where DEFAULT is either 'c' or 'c_global' or 'c_std'.
+dnl
+dnl To use the obsolete 'c_std' headers use --enable-cheaders-obsolete as
+dnl well as --enable-cheaders=c_std, otherwise configure will fail.
dnl
AC_DEFUN([GLIBCXX_ENABLE_CHEADERS], [
+ GLIBCXX_ENABLE(cheaders-obsolete,no,,
+ [allow use of obsolete "C" headers for g++])
GLIBCXX_ENABLE(cheaders,$1,[[[=KIND]]],
- [construct "C" headers for g++], [permit c|c_std|c_global])
+ [construct "C" headers for g++], [permit c|c_global|c_std])
AC_MSG_NOTICE("C" header strategy set to $enable_cheaders)
+ if test $enable_cheaders = c_std ; then
+ AC_MSG_WARN([the --enable-cheaders=c_std configuration is obsolete, c_global should be used instead])
+ AC_MSG_WARN([if you are unable to use c_global please report a bug or inform libstdc++@gcc.gnu.org])
+ if test $enable_cheaders_obsolete != yes ; then
+ AC_MSG_ERROR(use --enable-cheaders-obsolete to use c_std "C" headers)
+ fi
+ fi
C_INCLUDE_DIR='${glibcxx_srcdir}/include/'$enable_cheaders
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 845f2882ec1..7abf1b1ccc1 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -915,6 +915,7 @@ enable_cstdio
enable_clocale
enable_nls
enable_libstdcxx_allocator
+enable_cheaders_obsolete
enable_cheaders
enable_long_long
enable_wchar_t
@@ -1606,6 +1607,9 @@ Optional Features:
--enable-libstdcxx-allocator[=KIND]
use KIND for target std::allocator base
[default=auto]
+ --enable-cheaders-obsolete
+ allow use of obsolete "C" headers for g++
+ [default=no]
--enable-cheaders[=KIND]
construct "C" headers for g++ [default=$c_model]
--enable-long-long enable template specializations for 'long long'
@@ -12060,7 +12064,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 12063 "configure"
+#line 12067 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -12166,7 +12170,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 12169 "configure"
+#line 12173 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -15858,7 +15862,7 @@ $as_echo "$glibcxx_cv_atomic_long_long" >&6; }
# Fake what AC_TRY_COMPILE does.
cat > conftest.$ac_ext << EOF
-#line 15861 "configure"
+#line 15865 "configure"
int main()
{
typedef bool atomic_type;
@@ -15893,7 +15897,7 @@ $as_echo "$glibcxx_cv_atomic_bool" >&6; }
rm -f conftest*
cat > conftest.$ac_ext << EOF
-#line 15896 "configure"
+#line 15900 "configure"
int main()
{
typedef short atomic_type;
@@ -15928,7 +15932,7 @@ $as_echo "$glibcxx_cv_atomic_short" >&6; }
rm -f conftest*
cat > conftest.$ac_ext << EOF
-#line 15931 "configure"
+#line 15935 "configure"
int main()
{
// NB: _Atomic_word not necessarily int.
@@ -15964,7 +15968,7 @@ $as_echo "$glibcxx_cv_atomic_int" >&6; }
rm -f conftest*
cat > conftest.$ac_ext << EOF
-#line 15967 "configure"
+#line 15971 "configure"
int main()
{
typedef long long atomic_type;
@@ -16117,7 +16121,7 @@ $as_echo "mutex" >&6; }
# unnecessary for this test.
cat > conftest.$ac_ext << EOF
-#line 16120 "configure"
+#line 16124 "configure"
int main()
{
_Decimal32 d1;
@@ -16159,7 +16163,7 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
# unnecessary for this test.
cat > conftest.$ac_ext << EOF
-#line 16162 "configure"
+#line 16166 "configure"
template<typename T1, typename T2>
struct same
{ typedef T2 type; };
@@ -16193,7 +16197,7 @@ $as_echo "$enable_int128" >&6; }
rm -f conftest*
cat > conftest.$ac_ext << EOF
-#line 16196 "configure"
+#line 16200 "configure"
template<typename T1, typename T2>
struct same
{ typedef T2 type; };
@@ -16822,11 +16826,24 @@ $as_echo "$enable_libstdcxx_allocator_flag" >&6; }
+ # Check whether --enable-cheaders-obsolete was given.
+if test "${enable_cheaders_obsolete+set}" = set; then :
+ enableval=$enable_cheaders_obsolete;
+ case "$enableval" in
+ yes|no) ;;
+ *) as_fn_error $? "Argument to enable/disable cheaders-obsolete must be yes or no" "$LINENO" 5 ;;
+ esac
+
+else
+ enable_cheaders_obsolete=no
+fi
+
+
# Check whether --enable-cheaders was given.
if test "${enable_cheaders+set}" = set; then :
enableval=$enable_cheaders;
case "$enableval" in
- c|c_std|c_global) ;;
+ c|c_global|c_std) ;;
*) as_fn_error $? "Unknown argument to enable/disable cheaders" "$LINENO" 5 ;;
esac
@@ -16837,6 +16854,15 @@ fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: \"C\" header strategy set to $enable_cheaders" >&5
$as_echo "$as_me: \"C\" header strategy set to $enable_cheaders" >&6;}
+ if test $enable_cheaders = c_std ; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: the --enable-cheaders=c_std configuration is obsolete, c_global should be used instead" >&5
+$as_echo "$as_me: WARNING: the --enable-cheaders=c_std configuration is obsolete, c_global should be used instead" >&2;}
+ { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: if you are unable to use c_global please report a bug or inform libstdc++@gcc.gnu.org" >&5
+$as_echo "$as_me: WARNING: if you are unable to use c_global please report a bug or inform libstdc++@gcc.gnu.org" >&2;}
+ if test $enable_cheaders_obsolete != yes ; then
+ as_fn_error $? "use --enable-cheaders-obsolete to use c_std \"C\" headers" "$LINENO" 5
+ fi
+ fi
C_INCLUDE_DIR='${glibcxx_srcdir}/include/'$enable_cheaders
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