Re: [PATCH] use libcrypto routines in gnulib

[Pádraig Brady]

On 12/03/2013 05:47 PM, Paul Eggert wrote:
> On 12/03/2013 05:45 AM, Pádraig Brady wrote:
>> I'll probably do this in coreutils configure.ac before gl_INIT,
>> so as to at least set the default as coreutils wants and caters for,
>> and allowing users to --without-openssl if they want.
>>
>> dnl Enable use of libcrypto by default
>> AS_VAR_SET_IF([with_openssl], [], [with_openssl=maybe])
> 
> OK, but this means that the configure --help output is still wrong, since it
> says the default is 'no'?

Yes, this is a limitation when we cant to have a different default than gnulib.
I guess autoconf might be improved in future to allow overriding settings,
but for now I'm ok to live with this limitation for coreutils.

>> Hmm, I don't think the above mentioned fail if not available?
>> I'm using "maybe" above anyway, so that "yes" may be
>> treated like this in future.
> 
> Perhaps I'm reading too much into the standards, but that's how
> --with-jpeg etc. behave in GNU Emacs 'configure'.

Well I agree, that's how I expect --with options to work generally.
Making the existing gnulib --with options consistent in this regard
might be awkward due to backwards compat though.

So to have --with-openssl[=yes] fail without libcrypto
we'd have something along the lines of:

diff --git a/m4/gl-openssl.m4 b/m4/gl-openssl.m4
index f6c55b2..0396988 100644
--- a/m4/gl-openssl.m4
+++ b/m4/gl-openssl.m4
@@ -8,7 +8,8 @@ AC_DEFUN([gl_CRYPTO_CHECK],
 [
   AC_ARG_WITH([openssl],
     [AS_HELP_STRING([--with-openssl],
-      [use libcrypto hash routines if available: default=no])],
+      [use libcrypto hash routines. Valid options are:
+       'yes' => required, 'optional' => use if available, 'no' (default)])],
     [],
     [with_openssl=no])

@@ -26,9 +27,12 @@ AC_DEFUN([gl_CRYPTO_CHECK],
         [LIB_CRYPTO='-lcrypto'
          AC_DEFINE([HAVE_OPENSSL_$1],[1],
            [Define to 1 if libcrypto is used for $1])])])
-    if test "x$with_openssl" = xyes; then
-      if test "x$LIB_CRYPTO" = x; then
+    if test "x$LIB_CRYPTO" = x; then
+      if test "x$with_openssl" = xyes; then
+        AC_MSG_ERROR([openssl development library not found for $1])
+      else
         AC_MSG_WARN([openssl development library not found for $1])
+        AC_MSG_WARN([AC_PACKAGE_NAME will be built without libcrypto])
       fi
     fi
   fi