Does not build in IBM i PASE environment

[jwoehr]

Bug Report

In the IBM i PASE (it's based on IBM AIX) environment with PHP + extensions installed from http://repos.zend.com/ibmiphp and further extensions installed from http://repo.qseco.fr, the command pecl install mongodb downloads but the build fails as shown in the attached document.
pecl_mongodb_fail.txt

Environment

IBM i 7.4 PASE

$ uname -a
OS400 OPENSRC 4 7 00210002307W Os

[ThePrez]

At a glance, it looks like you might need to build with compiler define COMPAT_43 to build with the BSD 4.3-like functions that this seems to be using

[ThePrez]

I think the proper way to do this would be like so:

phpize
CFLAGS=-DCOMPAT_43 CPPFLAGS=-DCOMPAT_43 ./configure
make

[jwoehr]

Trying to build from github src

export OBJECT_MODE=64
export COMPAT_43=1
phpize > /dev/null && \
./configure --enable-mongodb-developer-flags > /dev/null && \
make clean > /dev/null && make all > /dev/null && make install

So far got this warning:
configure: WARNING: *** Please add powerpc-ibm-os400 to configure.ac checks!

[jwoehr]

Oops, @ThePrez slipped in. Starting again with script:

export OBJECT_MODE=64
cd mongo-php-driver
git submodule update --init
phpize > /dev/null && \
CFLAGS=-DCOMPAT_43 CPPFLAGS=-DCOMPAT_43 ./configure --enable-mongodb-developer-flags > /dev/null && \
make clean > /dev/null && make all > /dev/null && make install

[jwoehr]

Submodule 'src/libmongoc' (https://github.com/mongodb/mongo-c-driver.git) registered for path 'src/libmongoc'
Submodule 'src/libmongocrypt' (https://github.com/mongodb/libmongocrypt.git) registered for path 'src/libmongocrypt'
Cloning into '/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc'...
Cloning into '/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongocrypt'...
Submodule path 'src/libmongoc': checked out '60267532b6feddad7ab93097d8917fa1dd7195df'
Submodule path 'src/libmongocrypt': checked out '052f7fc610f0cea83a2adf3dd263a5ff04833371'
configure: WARNING: You will need re2c 0.13.4 or later if you want to regenerate PHP parsers.
configure: WARNING: *** Please add powerpc-ibm-os400 to configure.ac checks!
/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc/src/libbson/src/bson/bson-oid.c:35:23: warning: 'gHexCharPairs' defined but not used [-Wunused-const-variable=]
 static const uint16_t gHexCharPairs[] = {
                       ^~~~~~~~~~~~~
/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.c: In function 'mongoc_socket_accept_ex':
/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.c:731:15: error: 'struct sockaddr_storage' has no member named 'ss_family'; did you mean '__ss_family'?
       if (addr.ss_family == AF_INET) {
               ^
/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.c: In function '_mongoc_socket_try_sendv':
/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.c:1295:10: warning: implicit declaration of function 'sendmsg' [-Wimplicit-function-declaration]
    ret = sendmsg (sock->sd,
          ^~~~~~~
make: *** [Makefile:491: src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.lo] Error 1

[ThePrez]

Oops.... my analysis had it backwards. Mongoc doesn't use the 4.3-style, but the headers are compiled with COMPAT_43, hence the mismatch.
-UCOMPAT_43 might do something nice, but not betting on it...

[ThePrez]

I wonder if COMPAT_43 is set somewhere as a side effect of _BSD_SOURCE being set (or some such silliness) though I can't track down where such a thing may be happening.

As a desperate straw-grasping exercise, one might suggest adding an os400 leg to CheckHost.m4. I could envision it looking like

    *-*-linux*)
        os_gnu=yes
        TARGET_OS=unix
        ;;

[ThePrez]

Even better, just build libmongoc standalone and then build the php driver to use the system libmongoc (I believe this can be done via --with-libmongoc on the configure command and removing the mongoc directory as done here)

[ThePrez]

Sorry for the multiple updates.
Checking our libmongoc builds, we set -D_BSD=44 in CFLAGS. This must be what fixes the COMPAT_43 problem

So I think your path to success (without needing to build standalone libmongoc) is:

export OBJECT_MODE=64
phpize > /dev/null && \
CFLAGS="-D_BSD=44 -pthread" CPPFLAGS="-D_BSD=44 -pthread" LDFLAGS="-Wl,-bbigtoc -pthread" ./configure --enable-mongodb-developer-flags > /dev/null && \
make clean > /dev/null && make all > /dev/null && make install

[jwoehr]

$ cat ../build_driver.sh 
BREP=..build_report_` date '+%Y%m%dT%H:%M:%S'`.txt
export OBJECT_MODE=64
phpize >${BREP}&& \
CFLAGS="-D_BSD=44 -pthread" CPPFLAGS="-D_BSD=44 -pthread" LDFLAGS="-Wl,-bbigtoc -pthread" ./configure --enable-mongodb-developer-flags >>${BREP}&& \
make clean >>${BREP}&& make all >>${BREP}&& make install >>${BREP}

Same error.

/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.c: In function 'mongoc_socket_accept_ex':
/home/JWOEHR/work/PHP/mongo-php-driver/src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.c:731:15: error: 'struct sockaddr_storage' has no member named '__ss_family'; did you mean 'ss_family'?
       if (addr.ss_family == AF_INET) {
               ^
make: *** [Makefile:491: src/libmongoc/src/libmongoc/src/mongoc/mongoc-socket.lo] Error 1

[alcaeus]

This error is due to the detection of the ss_family member to sockaddr_storage not producing the expected result. Looking at FindDependencies.m4, we check for its existence using AC_CHECK_MEMBER and set MONGOC_HAVE_SS_FAMILY accordingly. Despite the confusing naming, this is set if sockaddr_storage has __ss_family instead of ss_family (see comment in mongoc-config.h.in). The check was added as counterpart to the check in libmongoc itself as seen in its build scripts.

I'm not sure what exactly is going wrong here, so I apologise for any guesswork while trying to resolve this. Here are some things you can try:

• Check config.log and src/libmongoc/src/libmongoc/src/mongoc/mongoc-config.h for the result of this check. The error message suggests that this value is 0, meaning that our check is wrong (since it obviously should be 1 due to the absence of sockaddr_storage.ss_family).
• Try compiling libmongoc by itself. I'll refer you to the build instructions in the libmongoc docs. If that build succeeds, that points to an error in our feature detection, while a failing build suggests a more general error in libmongoc.

As for the suggestion to compile libmongoc manually and using --with-libmongoc, please note that we deprecated this flag in favour of --with-system-libs. The reasoning here is that we always required you to specify both --with-libmongoc and --with-libbson, so having two separate flags for this didn't make sense, especially when we added libmongocrypt as an optional build dependency. The switch still works, just be aware that you'll have to provide system libmongoc and libbson for a build without bundled libraries to work.

Also, pinging @kevinAlbs as he was involved in the original fix and may be able to provide more insight as to what's going on here. Thanks for bearing with me while trying to figure out what's going on here!

[jwoehr]

@alcaeus Andreas, thanks for the tips. We will work on this and get back to you.

[NattyNarwhal]

I think the PHP driver side check is wrong.

In mongo-socket.h:

#if defined(_AIX) && !defined(MONGOC_HAVE_SS_FAMILY)
# define ss_family __ss_family
#endif

But in, FindDependencies.m4, the definitions seem reversed according to AC_CHECK_MEMBER:

# Check for sched_getcpu
AC_CHECK_FUNC([sched_getcpu],
              [AC_SUBST(MONGOC_HAVE_SCHED_GETCPU, 1)],
              [AC_SUBST(MONGOC_HAVE_SCHED_GETCPU, 0)])

AC_CHECK_TYPE([socklen_t],
              [AC_SUBST(MONGOC_HAVE_SOCKLEN, 1)],
              [AC_SUBST(MONGOC_HAVE_SOCKLEN, 0)],
              [#include <sys/socket.h>])

AC_CHECK_MEMBER([struct sockaddr_storage.ss_family],
                [AC_SUBST(MONGOC_HAVE_SS_FAMILY, 0)],
                [AC_SUBST(MONGOC_HAVE_SS_FAMILY, 1)],
                [#include <sys/socket.h>])

So the definition is set to 0, so then mongo-config.h will undefine MONGOC_HAVE_SS_FAMILY.

When I reverse the 0/1 in the ss_family check, it builds without any compatibility flags or other changes. I think the autotools/cmake checks from normal Mongo libraries should work like this too, but the PHP module doesn't use their build scripts even with the vendored copy.

[alcaeus]

@NattyNarwhal thank you for confirming this. When I first took a look I was convinced it was wrong, then convinced myself otherwise after reading the code some more. 🤦‍♂️

I've created #1169 to fix this, and we're also tracking this internally as PHPC-1703. We'll have this released in the upcoming driver patch release (currently scheduled for the first Tuesday in November).