Use libcrypto's checksum implementations if available, for speed.

On commonly used platform libcrypto uses architecture-specific
assembly code, which is significantly faster than the C code we
were using.  See Pádraig Brady's note in
<http://lists.gnu.org/archive/html/bug-gnulib/2013-12/msg00000.html>.
Merge from gnulib, incorporating:
2013-12-07 md5, sha1, sha256, sha512: add gl_SET_CRYPTO_CHECK_DEFAULT
2013-12-07 md5, sha1, sha256, sha512: add 'auto', and set-default method
2013-12-04 include_next: minimize code duplication
2013-12-03 md5, sha1, sha256, sha512: support mandating use of openssl
2013-12-02 md5, sha1, sha256, sha512: use openssl routines if available
* configure.ac (--without-all): Set with_openssl_default too.
Use gl_SET_CRYPTO_CHECK_DEFAULT to default to 'auto'.
(HAVE_LIB_CRYPTO): New var.
Say whether Emacs is configured to use a crypto library.
* lib/gl_openssl.h, m4/absolute-header.m4, m4/gl-openssl.m4:
New files, copied from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib/md5.c, lib/md5.h, lib/sha1.c, lib/sha1.h:
* lib/sha256.c, lib/sha256.h, lib/sha512.c, lib/sha512.h:
* m4/include_next.m4, m4/md5.m4, m4/sha1.m4, m4/sha256.m4, m4/sha512.m4:
Update from gnulib.
* src/Makefile.in (LIB_CRYPTO): New macro.
(LIBES): Use it.

1 files changed, 3 insertions, 50 deletions

diff --git a/m4/include_next.m4 b/m4/include_next.m4
index 108d945677f..f09dbe66395 100644
--- a/m4/include_next.m4
+++ b/m4/include_next.m4
@@ -192,56 +192,9 @@ dnl until we can assume autoconf 2.64 or newer.
              if test AS_VAR_GET(gl_header_exists) = yes; then
              AS_VAR_POPDEF([gl_header_exists])
             ])
-               AC_LANG_CONFTEST(
-                 [AC_LANG_SOURCE(
-                    [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
-                  )])
-               dnl AIX "xlc -E" and "cc -E" omit #line directives for header
-               dnl files that contain only a #include of other header files and
-               dnl no non-comment tokens of their own. This leads to a failure
-               dnl to detect the absolute name of <dirent.h>, <signal.h>,
-               dnl <poll.h> and others. The workaround is to force preservation
-               dnl of comments through option -C. This ensures all necessary
-               dnl #line directives are present. GCC supports option -C as well.
-               case "$host_os" in
-                 aix*) gl_absname_cpp="$ac_cpp -C" ;;
-                 *)    gl_absname_cpp="$ac_cpp" ;;
-               esac
-changequote(,)
-               case "$host_os" in
-                 mingw*)
-                   dnl For the sake of native Windows compilers (excluding gcc),
-                   dnl treat backslash as a directory separator, like /.
-                   dnl Actually, these compilers use a double-backslash as
-                   dnl directory separator, inside the
-                   dnl   # line "filename"
-                   dnl directives.
-                   gl_dirsep_regex='[/\\]'
-                   ;;
-                 *)
-                   gl_dirsep_regex='\/'
-                   ;;
-               esac
-               dnl A sed expression that turns a string into a basic regular
-               dnl expression, for use within "/.../".
-               gl_make_literal_regex_sed='s,[]$^\\.*/[],\\&,g'
-changequote([,])
-               gl_header_literal_regex=`echo ']m4_defn([gl_HEADER_NAME])[' \
-                                        | sed -e "$gl_make_literal_regex_sed"`
-               gl_absolute_header_sed="/${gl_dirsep_regex}${gl_header_literal_regex}/"'{
-                   s/.*"\(.*'"${gl_dirsep_regex}${gl_header_literal_regex}"'\)".*/\1/
-changequote(,)dnl
-                   s|^/[^/]|//&|
-changequote([,])dnl
-                   p
-                   q
-                 }'
-               dnl eval is necessary to expand gl_absname_cpp.
-               dnl Ultrix and Pyramid sh refuse to redirect output of eval,
-               dnl so use subshell.
-               AS_VAR_SET(gl_next_header,
-                 ['"'`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
-                      sed -n "$gl_absolute_header_sed"`'"'])
+           gl_ABSOLUTE_HEADER_ONE(gl_HEADER_NAME)
+           AS_VAR_COPY([gl_header], [gl_cv_absolute_]AS_TR_SH(gl_HEADER_NAME))
+           AS_VAR_SET(gl_next_header, ['"'$gl_header'"'])
           m4_if([$2], [check],
             [else
                AS_VAR_SET(gl_next_header, ['<'gl_HEADER_NAME'>'])