configure: Disable building libcrypt by default

We mentioned eventual dropping of libcrypt in the 2.28 NEWS.  Actually
put that plan in motion by first disabling building libcrypt by default.
note in NEWS that the library will be dropped completely in a future
release.

Also add a couple of builds into build-many-glibcs.py.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Andreas K. Hüttel <dilfridge@gentoo.org>

INSTALL

@@ -228,16 +228,18 @@ if ‘CFLAGS’ is specified it must enable optimization.  For example:
      By default for x86_64, the GNU C Library is built with the vector
      math library.  Use this option to disable the vector math library.
 
-‘--disable-crypt’
-     Do not install the passphrase-hashing library ‘libcrypt’ or the
-     header file ‘crypt.h’.  ‘unistd.h’ will still declare the function
-     ‘crypt’.  Using this option does not change the set of programs
-     that may need to be linked with ‘-lcrypt’; it only means that the
-     GNU C Library will not provide that library.
+‘--enable-crypt’
+     Install the legacy passphrase-hashing library ‘libcrypt’ and the
+     header file ‘crypt.h’.  ‘unistd.h’ will declare the function
+     ‘crypt’ regardless of this option.  Using this option does not
+     change the set of programs that may need to be linked with
+     ‘-lcrypt’; it only means that the GNU C Library will provide that
+     library.
 
-     This option is for hackers and distributions experimenting with
-     independently-maintained implementations of libcrypt.  It may
-     become the default in a future release.
+     This option is for hackers and distributions who may not yet be
+     able to use libcrypt alternatives such as libxcrypt and need this
+     legacy implementation as a temporary workaround.  Note that
+     libcrypt may be removed in a future release.
 
 ‘--disable-scv’
      Disable using ‘scv’ instruction for syscalls.  All syscalls will

NEWS

@@ -56,6 +56,11 @@ Major new features:
 
 Deprecated and removed features, and other changes affecting compatibility:
 
+* libcrypt is no longer built by default, one may use the --enable-crypt
+  option to build libcrypt.  libcrypt is likely to be removed from the
+  GNU C Library in a future release, so it is recommended that
+  applications port away from it to an alternative such as libxcrypt.
+
 * In the Linux kernel for the hppa/parisc architecture some of the
   MADV_XXX constants were changed to have the same values as the other
   architectures.  New programs compiled with this glibc version and which

configure

@@ -1484,7 +1484,7 @@ Optional Features:
                           architectures
   --enable-memory-tagging enable memory tagging if supported by the
                           architecture [default=no]
-  --disable-crypt         do not build nor install the passphrase hashing
+  --enable-crypt          build and install the legacy passphrase hashing
                           library, libcrypt
   --enable-nss-crypt      enable libcrypt to use nss
   --enable-systemtap      enable systemtap static probe points [default=no]
@@ -4577,7 +4577,7 @@ if test ${enable_crypt+y}
 then :
   enableval=$enable_crypt; build_crypt=$enableval
 else $as_nop
-  build_crypt=yes
+  build_crypt=no
 fi
 
 

configure.ac

@@ -316,10 +316,10 @@ fi
 AC_SUBST(memory_tagging)
 
 AC_ARG_ENABLE([crypt],
-              AS_HELP_STRING([--disable-crypt],
-                             [do not build nor install the passphrase hashing library, libcrypt]),
+              AS_HELP_STRING([--enable-crypt],
+                             [build and install the legacy passphrase hashing library, libcrypt]),
               [build_crypt=$enableval],
-              [build_crypt=yes])
+              [build_crypt=no])
 AC_SUBST(build_crypt)
 
 AC_ARG_ENABLE([nss-crypt],

manual/install.texi

@@ -256,16 +256,18 @@ configure with @option{--disable-werror}.
 By default for x86_64, @theglibc{} is built with the vector math library.
 Use this option to disable the vector math library.
 
-@item --disable-crypt
-Do not install the passphrase-hashing library @file{libcrypt} or the
-header file @file{crypt.h}.  @file{unistd.h} will still declare the
-function @code{crypt}.  Using this option does not change the set of
-programs that may need to be linked with @option{-lcrypt}; it only
-means that @theglibc{} will not provide that library.
+@item --enable-crypt
+Install the legacy passphrase-hashing library @file{libcrypt} and the
+header file @file{crypt.h}.  @file{unistd.h} will declare the function
+@code{crypt} regardless of this option.  Using this option does not
+change the set of programs that may need to be linked with
+@option{-lcrypt}; it only means that @theglibc{} will provide that
+library.
 
-This option is for hackers and distributions experimenting with
-independently-maintained implementations of libcrypt.  It may become
-the default in a future release.
+This option is for hackers and distributions who may not yet be able to
+use libcrypt alternatives such as libxcrypt and need this legacy
+implementation as a temporary workaround.  Note that libcrypt may be
+removed in a future release.
 
 @item --disable-scv
 Disable using @code{scv} instruction for syscalls. All syscalls will use

scripts/build-many-glibcs.py

@@ -431,7 +431,9 @@ class Context(object):
                                       {'variant': 'disable-multi-arch',
                                        'arch': 'sparcv9',
                                        'ccopts': '-m32 -mlong-double-128 -mcpu=v9',
-                                       'cfg': ['--disable-multi-arch']}])
+                                       'cfg': ['--disable-multi-arch']},
+                                      {'variant': 'enable-crypt',
+                                       'cfg': ['--enable-crypt']}])
         self.add_config(arch='x86_64',
                         os_name='linux-gnu',
                         gcc_cfg=['--with-multilib-list=m64,m32,mx32'],
@@ -466,7 +468,9 @@ class Context(object):
                                       {'arch': 'i586',
                                        'ccopts': '-m32 -march=i586'},
                                       {'variant': 'enable-fortify-source',
-                                       'cfg': ['--enable-fortify-source']}])
+                                       'cfg': ['--enable-fortify-source']},
+                                      {'variant': 'enable-crypt',
+                                       'cfg': ['--enable-crypt']}])
         self.add_config(arch='x86_64',
                         os_name='gnu',
                         gcc_cfg=['--disable-multilib'])