AIX platforms shouldn't try linking with libresolv #1171
Description
Bug Report
mongodb+srv:// URIs don't work on AIX platforms (including IBM i PASE). This is because the configure script for vendored libmongoc hardcodes -lresolv linker flags, which prevents the checks for the libresolv functions from working. On AIX, the resolver functions are in libc, so checking for libresolv should be optional. (AC_SEARCH_LIBS would be appropriate, but the script in CheckResolv.m4 is more complicated than that.)
Removing the hardcoded -lresolv worked, but I suspect you might want a more graceful solution that doesn't need to hardcode per platform. My "remove hardcoded library, add hardcoded platform workaround" patch is:
diff --git a/scripts/autotools/CheckHost.m4 b/scripts/autotools/CheckHost.m4
index 52448385..e33ebce1 100644
--- a/scripts/autotools/CheckHost.m4
+++ b/scripts/autotools/CheckHost.m4
@@ -9,6 +9,7 @@ os_linux=no
os_solaris=no
os_darwin=no
os_gnu=no
+os_aix=no
case "$host" in
*-mingw*|*-*-cygwin*)
@@ -44,6 +45,10 @@ case "$host" in
os_darwin=yes
TARGET_OS=unix
;;
+ *-*-aix*|*-*-os400*)
+ os_aix=yes
+ TARGET_OS=unix
+ ;;
gnu*|k*bsd*-gnu*)
os_gnu=yes
TARGET_OS=unix
diff --git a/scripts/autotools/libmongoc/CheckResolv.m4 b/scripts/autotools/libmongoc/CheckResolv.m4
index 5cfa238c..15bbdfd5 100644
--- a/scripts/autotools/libmongoc/CheckResolv.m4
+++ b/scripts/autotools/libmongoc/CheckResolv.m4
@@ -2,9 +2,13 @@ dnl Disable Windows DNSAPI
AC_SUBST(MONGOC_HAVE_DNSAPI, 0)
found_resolv="no"
+need_libresolv="no"
old_LIBS="$LIBS"
-LIBS="$LIBS -lresolv"
+dnl On AIX, resolv functions are in libc.
+if test "x$os_aix" = "xno"; then
+ LIBS="$LIBS -lresolv"
+fi
dnl Thread-safe DNS query function for _mongoc_client_get_srv.
dnl Could be a macro, not a function, so check with AC_LINK_IFELSE.
@@ -80,7 +84,9 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM([[
]])], [
AC_MSG_RESULT([yes])
AC_SUBST(MONGOC_HAVE_RES_SEARCH, 1)
- found_resolv="yes"
+ if test "x$os_aix" = "xno"; then
+ need_libresolv="yes"
+ fi
], [
AC_MSG_RESULT([no])
AC_SUBST(MONGOC_HAVE_RES_SEARCH, 0)
@@ -89,6 +95,6 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM([[
LIBS="$old_LIBS"
-AS_IF([test "$found_resolv" = "yes"],[
+AS_IF([test "$need_libresolv" = "yes"],[
PHP_ADD_LIBRARY([resolv],,[MONGODB_SHARED_LIBADD])
])Environment
IBM i PASE (but as mentioned, any AIX platform will be the same)
Test Script
Anything that connects with a mongodb+srv:// URL.
Expected and Actual Behavior
Error with broken libresolv support (from @jwoehr):
Uncaught MongoDB\Driver\Exception\ConnectionTimeoutException: libresolv unavailable, cannot use mongodb+srv URI in /home/JWOEHR/work/PHP/vendor/mongodb/mongodb/src/functions.php:431
Stack trace:
#0 /home/JWOEHR/work/PHP/vendor/mongodb/mongodb/src/functions.php(431): MongoDB\Driver\Manager->selectServer(Object(MongoDB\Driver\ReadPreference))
#1 /home/JWOEHR/work/PHP/vendor/mongodb/mongodb/src/Collection.php(651): MongoDB\select_server(Object(MongoDB\Driver\Manager), Array)
#2 php shell code(1): MongoDB\Collection->find()
#3 {main}
thrown in /home/JWOEHR/work/PHP/vendor/mongodb/mongodb/src/functions.php on line 431
Debug Log
Unnecessary.