Drop function wrapping as it is redundant for now

As currently used in the BIND source tree, the --wrap linker option is
redundant because:

  - static builds are no longer supported,

  - there is no need to wrap around existing functions - what is
    actually required (at least for now) is to replace them altogether
    in unit tests,

  - only functions exposed by shared libraries linked into unit test
    binaries are currently being replaced.

Given the above, providing the alternative implementations of functions
to be overridden in lib/ns/tests/nstest.c is a much simpler alternative
to using the --wrap linker option.  Drop the code detecting support for
the latter from configure.ac, simplify the relevant Makefile.am, and
remove lib/ns/tests/wrap.c, updating lib/ns/tests/nstest.c accordingly
(it is harmless for unit tests which are not calling the overridden
functions).

configure.ac

@@ -1354,44 +1354,6 @@ AC_SUBST([CMOCKA_LIBS])
 
 AM_CONDITIONAL([HAVE_CMOCKA], [test "$with_cmocka" = "yes"])
 
-#
-# Check for -Wl,--wrap= support
-#
-
-LD_WRAP_TESTS=false
-AC_MSG_CHECKING([for linker support for --wrap option])
-AX_SAVE_FLAGS([wrap])
-LDFLAGS="-Wl,--wrap,exit"
-AC_RUN_IFELSE(
-    [AC_LANG_PROGRAM([[#include <stdlib.h>
-		       void __real_exit (int status);
-		       void __wrap_exit (int status) { __real_exit (0); }
-		      ]],
-		     [[exit (1);]])],
-    [LD_WRAP_TESTS=true
-     AC_MSG_RESULT([yes])],
-    [AC_MSG_RESULT([no])])
-AX_RESTORE_FLAGS([wrap])
-
-AM_CONDITIONAL([HAVE_LD_WRAP], [test "$LD_WRAP_TESTS" = "true"])
-
-WRAP_INTERPOSE=
-AC_MSG_CHECKING([for linker support for '-z interpose' option])
-AX_SAVE_FLAGS([interpose])
-LDFLAGS="-Wl,-z,interpose"
-AC_LINK_IFELSE(
-    [AC_LANG_PROGRAM([],[])],
-    [WRAP_INTERPOSE="-Wl,-z,interpose"
-     AC_MSG_RESULT([yes])],
-    [AC_MSG_RESULT([no])])
-AX_RESTORE_FLAGS([interpose])
-
-AC_SUBST([WRAP_INTERPOSE])
-
-WRAP_NAME=''
-AS_CASE([$host],[*-darwin*],[WRAP_NAME='${WRAP_NAME}'])
-AC_SUBST([WRAP_NAME])
-
 #
 # Check for i18n
 #

lib/ns/tests/Makefile.am

@@ -13,37 +13,17 @@ LDADD +=			\
 	$(LIBNS_LIBS)
 
 check_LTLIBRARIES = libnstest.la
-libnstest_la_SOURCES = nstest.c nstest.h
+libnstest_la_SOURCES =		\
+	nstest.c 		\
+	nstest.h
+
 check_PROGRAMS =		\
 	listenlist_test		\
-	plugin_test
-
-TESTS = $(check_PROGRAMS)
-
-if HAVE_LD_WRAP
-
-check_PROGRAMS +=	\
-	notify_test	\
+	notify_test		\
+	plugin_test		\
 	query_test
 
-notify_test_SOURCES =	\
-	notify_test.c	\
-	wrap.c
-
-notify_test_LDFLAGS =			\
-	$(LDFLAGS)			\
-	-Wl,--wrap=isc_nmhandle_attach	\
-	-Wl,--wrap=isc_nmhandle_detach
-
-query_test_SOURCES =	\
-	query_test.c	\
-	wrap.c
-
-query_test_LDFLAGS =			\
-	$(LDFLAGS)			\
-	-Wl,--wrap=isc_nmhandle_detach
-
-endif
+TESTS = $(check_PROGRAMS)
 
 unit-local: check
 

lib/ns/tests/nstest.c

@@ -78,12 +78,7 @@ atomic_uint_fast32_t client_refs[32];
 atomic_uintptr_t client_addrs[32];
 
 void
-__wrap_isc_nmhandle_attach(isc_nmhandle_t *source, isc_nmhandle_t **targetp);
-void
-__wrap_isc_nmhandle_detach(isc_nmhandle_t **handlep);
-
-void
-__wrap_isc_nmhandle_attach(isc_nmhandle_t *source, isc_nmhandle_t **targetp) {
+isc_nmhandle_attach(isc_nmhandle_t *source, isc_nmhandle_t **targetp) {
 	ns_client_t *client = (ns_client_t *)source;
 	int i;
 
@@ -102,7 +97,7 @@ __wrap_isc_nmhandle_attach(isc_nmhandle_t *source, isc_nmhandle_t **targetp) {
 }
 
 void
-__wrap_isc_nmhandle_detach(isc_nmhandle_t **handlep) {
+isc_nmhandle_detach(isc_nmhandle_t **handlep) {
 	isc_nmhandle_t *handle = *handlep;
 	ns_client_t *client = (ns_client_t *)handle;
 	int i;

lib/ns/tests/wrap.c

@@ -1,47 +0,0 @@
-/*
- * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, you can obtain one at https://mozilla.org/MPL/2.0/.
- *
- * See the COPYRIGHT file distributed with this work for additional
- * information regarding copyright ownership.
- */
-
-/*! \file */
-
-#include <inttypes.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <time.h>
-#include <unistd.h>
-
-#include <isc/mem.h>
-#include <isc/netmgr.h>
-#include <isc/util.h>
-
-#include <dns/view.h>
-
-#include <ns/client.h>
-
-/*
- * This overrides calls to isc_nmhandle_attach/detach(), sending them to
- * __wrap_isc_nmhandle_attach/detach() instead, when libtool is in use
- * and LD_WRAP can't be used.
- */
-
-void
-__wrap_isc_nmhandle_attach(isc_nmhandle_t *source, isc_nmhandle_t **targetp);
-extern void
-__wrap_isc_nmhandle_detach(isc_nmhandle_t **handlep);
-
-void
-isc_nmhandle_attach(isc_nmhandle_t *source, isc_nmhandle_t **targetp) {
-	__wrap_isc_nmhandle_attach(source, targetp);
-}
-
-void
-isc_nmhandle_detach(isc_nmhandle_t **handlep) {
-	__wrap_isc_nmhandle_detach(handlep);
-}

util/copyrights

@@ -2124,7 +2124,6 @@
 ./lib/ns/tests/plugin_test.c			C	2019,2020
 ./lib/ns/tests/query_test.c			C	2017,2018,2019,2020
 ./lib/ns/tests/testdata/notify/notify1.msg	X	2017,2018,2019,2020
-./lib/ns/tests/wrap.c				C	2019,2020
 ./lib/ns/update.c				C	2017,2018,2019,2020
 ./lib/ns/win32/DLLMain.c			C	2017,2018,2019,2020
 ./lib/ns/win32/libns.def			X	2017,2018,2019,2020