[gcc r11-9757] libstdc++: Improve config output for --enable-cstdio [PR104301]

[gcc r11-9757] libstdc++: Improve config output for --enable-cstdio [PR104301]

[Jonathan Wakely]

https://gcc.gnu.org/g:e6503952a2f884917b52d0f4ae2707d25f1a0a39

commit r11-9757-ge6503952a2f884917b52d0f4ae2707d25f1a0a39
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Jan 31 11:00:18 2022 +0000

    libstdc++: Improve config output for --enable-cstdio [PR104301]
    
    Currently we just print "checking for underlying I/O to use... stdio"
    unconditionally, whether configured to use stdio_pure or stdio_posix. We
    should make it clear that the user's configure option chose the right
    thing.
    
    libstdc++-v3/ChangeLog:
    
            PR libstdc++/104301
            * acinclude.m4 (GLIBCXX_ENABLE_CSTDIO): Print different messages
            for stdio_pure and stdio_posix options.
            * configure: Regenerate.
    
    (cherry picked from commit 19b8946dbda5fda4389ef8e3ea162c3df2b1998d)

Diff:
---
 libstdc++-v3/acinclude.m4 | 4 +++-
 libstdc++-v3/configure    | 7 +++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 56405328844..15c975ff86e 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -2857,11 +2857,13 @@ AC_DEFUN([GLIBCXX_ENABLE_CSTDIO], [
       CSTDIO_H=config/io/c_io_stdio.h
       BASIC_FILE_H=config/io/basic_file_stdio.h
       BASIC_FILE_CC=config/io/basic_file_stdio.cc
-      AC_MSG_RESULT(stdio)
 
       if test "x$enable_cstdio" = "xstdio_pure" ; then
+	AC_MSG_RESULT([stdio (without POSIX read/write)])
 	AC_DEFINE(_GLIBCXX_USE_STDIO_PURE, 1,
 		  [Define to restrict std::__basic_file<> to stdio APIs.])
+      else
+	AC_MSG_RESULT([stdio (with POSIX read/write)])
       fi
       ;;
   esac
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index acf20989c9e..6c9125e39e4 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -16425,13 +16425,16 @@ fi
       CSTDIO_H=config/io/c_io_stdio.h
       BASIC_FILE_H=config/io/basic_file_stdio.h
       BASIC_FILE_CC=config/io/basic_file_stdio.cc
-      { $as_echo "$as_me:${as_lineno-$LINENO}: result: stdio" >&5
-$as_echo "stdio" >&6; }
 
       if test "x$enable_cstdio" = "xstdio_pure" ; then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: stdio (without POSIX read/write)" >&5
+$as_echo "stdio (without POSIX read/write)" >&6; }
 
 $as_echo "#define _GLIBCXX_USE_STDIO_PURE 1" >>confdefs.h
 
+      else
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: stdio (with POSIX read/write)" >&5
+$as_echo "stdio (with POSIX read/write)" >&6; }
       fi
       ;;
   esac