bpo-32598: Use autoconf to detect usable OpenSSL (#5242)

Add https://www.gnu.org/software/autoconf-archive/ax_check_openssl.html
to auto-detect compiler flags, linker flags and libraries to compile
OpenSSL extensions. The M4 macro uses pkg-config and falls back to
manual detection.

Add autoconf magic to detect usable X509_VERIFY_PARAM_set1_host()
and related functions.

Refactor setup.py to use new config vars to compile _ssl and _hashlib
modules.

Signed-off-by: Christian Heimes <christian@python.org>

1 files changed, 73 insertions, 4 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index 61b2539d2e..0969496291 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -12,9 +12,9 @@
 # PARTICULAR PURPOSE.
 
 m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
-dnl pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
-dnl serial 11 (pkg-config-0.29)
-dnl
+# pkg.m4 - Macros to locate and utilise pkg-config.   -*- Autoconf -*-
+# serial 11 (pkg-config-0.29.1)
+
 dnl Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
 dnl Copyright © 2012-2015 Dan Nicholson <dbn.lists@gmail.com>
 dnl
@@ -55,7 +55,7 @@ dnl
 dnl See the "Since" comment for each macro you use to see what version
 dnl of the macros you require.
 m4_defun([PKG_PREREQ],
-[m4_define([PKG_MACROS_VERSION], [0.29])
+[m4_define([PKG_MACROS_VERSION], [0.29.1])
 m4_if(m4_version_compare(PKG_MACROS_VERSION, [$1]), -1,
     [m4_fatal([pkg.m4 version $1 or higher is required but ]PKG_MACROS_VERSION[ found])])
 ])dnl PKG_PREREQ
@@ -288,3 +288,72 @@ AS_VAR_COPY([$1], [pkg_cv_][$1])
 AS_VAR_IF([$1], [""], [$5], [$4])dnl
 ])dnl PKG_CHECK_VAR
 
+dnl PKG_WITH_MODULES(VARIABLE-PREFIX, MODULES,
+dnl   [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND],
+dnl   [DESCRIPTION], [DEFAULT])
+dnl ------------------------------------------
+dnl
+dnl Prepare a "--with-" configure option using the lowercase
+dnl [VARIABLE-PREFIX] name, merging the behaviour of AC_ARG_WITH and
+dnl PKG_CHECK_MODULES in a single macro.
+AC_DEFUN([PKG_WITH_MODULES],
+[
+m4_pushdef([with_arg], m4_tolower([$1]))
+
+m4_pushdef([description],
+           [m4_default([$5], [build with ]with_arg[ support])])
+
+m4_pushdef([def_arg], [m4_default([$6], [auto])])
+m4_pushdef([def_action_if_found], [AS_TR_SH([with_]with_arg)=yes])
+m4_pushdef([def_action_if_not_found], [AS_TR_SH([with_]with_arg)=no])
+
+m4_case(def_arg,
+            [yes],[m4_pushdef([with_without], [--without-]with_arg)],
+            [m4_pushdef([with_without],[--with-]with_arg)])
+
+AC_ARG_WITH(with_arg,
+     AS_HELP_STRING(with_without, description[ @<:@default=]def_arg[@:>@]),,
+    [AS_TR_SH([with_]with_arg)=def_arg])
+
+AS_CASE([$AS_TR_SH([with_]with_arg)],
+            [yes],[PKG_CHECK_MODULES([$1],[$2],$3,$4)],
+            [auto],[PKG_CHECK_MODULES([$1],[$2],
+                                        [m4_n([def_action_if_found]) $3],
+                                        [m4_n([def_action_if_not_found]) $4])])
+
+m4_popdef([with_arg])
+m4_popdef([description])
+m4_popdef([def_arg])
+
+])dnl PKG_WITH_MODULES
+
+dnl PKG_HAVE_WITH_MODULES(VARIABLE-PREFIX, MODULES,
+dnl   [DESCRIPTION], [DEFAULT])
+dnl -----------------------------------------------
+dnl
+dnl Convenience macro to trigger AM_CONDITIONAL after PKG_WITH_MODULES
+dnl check._[VARIABLE-PREFIX] is exported as make variable.
+AC_DEFUN([PKG_HAVE_WITH_MODULES],
+[
+PKG_WITH_MODULES([$1],[$2],,,[$3],[$4])
+
+AM_CONDITIONAL([HAVE_][$1],
+               [test "$AS_TR_SH([with_]m4_tolower([$1]))" = "yes"])
+])dnl PKG_HAVE_WITH_MODULES
+
+dnl PKG_HAVE_DEFINE_WITH_MODULES(VARIABLE-PREFIX, MODULES,
+dnl   [DESCRIPTION], [DEFAULT])
+dnl ------------------------------------------------------
+dnl
+dnl Convenience macro to run AM_CONDITIONAL and AC_DEFINE after
+dnl PKG_WITH_MODULES check. HAVE_[VARIABLE-PREFIX] is exported as make
+dnl and preprocessor variable.
+AC_DEFUN([PKG_HAVE_DEFINE_WITH_MODULES],
+[
+PKG_HAVE_WITH_MODULES([$1],[$2],[$3],[$4])
+
+AS_IF([test "$AS_TR_SH([with_]m4_tolower([$1]))" = "yes"],
+        [AC_DEFINE([HAVE_][$1], 1, [Enable ]m4_tolower([$1])[ support])])
+])dnl PKG_HAVE_DEFINE_WITH_MODULES
+
+m4_include([m4/ax_check_openssl.m4])