#1238 wsdl tool doesn't build on alpine

[Mindaugas Vinkelis]

wsdl tools doesn't compile, when compiling directly by using make -f MakefileManual secure.
I made docker image, that easily reproduces this bug, as well as a patch file, that fixed it.
In stdsoap2.h the issue might be with alpine itself, because it takes last options to define SOAP_SOCKLEN_T, but other compile errors looks like a bug in stdsoap2.cpp because it check if particular linux function exists, but calls it with incorrect signature.

[Mindaugas Vinkelis]

to test it is very simple (if you have docker)
just run
docker build -t test_alpine_gsoap .

[Robert van Engelen]

Sorry but this patch is not very useful. You need to tell us which compile-time macros are set by the compiler on Alpine so we can add an #if branch. There are already OS-depenent checks for gethostbyname_r, strerror_r, and SOCKLEN_T. So we just need to add compile-time #if checks (and branch if neeed) for Alpine. Thanks.

[Mindaugas Vinkelis]

1) enter docker container
docker run -it n0madic/alpine-gcc:8.2.0 /bin/bash
2) dump preprocessor defines for c++ (https://stackoverflow.com/questions/2224334/gcc-dump-preprocessor-defines)
g++ -dM -E -x c++ - < /dev/null
there are too many of them, so i added file attachment.
Hope that helps :)

[Robert van Engelen]

Surprisingly Alpine Linux defines _GNU_SOURCE 1 which means that non-standard functions are available. But those do not compile. Alpine also does not define _XOPEN_SOURCE or _POSIX_C_SOURCE so just defining _GNU_SOURCE 1 is just plain wrong! See e.g. https://stackoverflow.com/questions/5582211/what-does-define-gnu-source-imply

[Robert van Engelen]

Can you try the attached update for 2.8.80? I wasn't able to use docker in the way you suggested.

[Mindaugas Vinkelis]

Updated Dockerfile (now use latest alpine version: 3.9 with gcc 8.2.0 ), in case you're interested, and your patch fixed almost all problems, except this one:
../stdsoap2.cpp: In function 'const char soap_strerror(soap)':
../stdsoap2.cpp:22358:22: error: invalid conversion from 'int' to 'const char' [-fpermissive]
return strerror_r(err, soap->msgbuf, sizeof(soap->msgbuf)); / GNU-specific */

Don't know how to solve this, maybe it should be reported to alpine?

[Robert van Engelen]

Change the soap_strerror code as follows and let me know if this change compiles on Alpine;

# ifdef HAVE_STRERROR_R
#  if (!_GNU_SOURCE && !defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)) || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600 || defined(__ANDROID__) || defined(__GLIBC__) || defined(__GNU__) || defined(__GNUC__) || defined(FREEBSD) || defined(__FreeBSD__) || defined(OPENBSD)
    strerror_r(err, soap->msgbuf, sizeof(soap->msgbuf)); /* XSI-compliant */

[Robert van Engelen]

Ignore the previous message. Please try the attached patch. Thanks!

[Mindaugas Vinkelis]

Hello,
Now it works like a charm ;) thanks!
Tested on three alpine distros with different compilers:
alpine 3.9 (g++ 8.2.0)
alpine 3.8 (g++ 6.4.0-r9)
alipne 3.3 (g++ 5.3.0)

[Robert van Engelen]

Bad news. This change does not work on some systems such as Solaris. It seems to me that Alpine Linux has macros set that should not be as I pointed out.

I need to change stdsoap2.cpp/.c function tcp_gethostbyname() the line before the line that calls gethostbyname_r to the following:

#if defined(__GLIBC__) && (!_GNU_SOURCE && !defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE) && defined(HAVE_GETHOSTBYNAME_R)) || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600 || defined(__ANDROID__) || (defined(HAVE_GETHOSTBYNAME_R) && (defined(FREEBSD) || defined(__FreeBSD__)))
  while ((r = gethostbyname_r(addr, hostent, tmpbuf, tmplen, &hostent, &soap->errnum)) < 0)

Let me know if this breaks Alpine builds and how you plan to fix that since I am giving up on Alpine.

[Robert van Engelen]

I've added a Docker example of gSOAP with Alpine, see https://www.genivia.com/examples/docker

The problem with gethostbyname_r is mentioned there. Upcoming version 2.8.87 will hopefully have a fix once and for all.