getpeername/getnameinfo not detected by configure test

[Beuc]

Hi,

While compiling Python's _socket module, I noticed that getpeername and getnameinfo were mistakenly detected as not present.

Something appears to confuse emscripten in the configuration test, as it returns a link error with htons:

$ emcc -o conftest    conftest.c -ldl
warning: unexpected number of arguments 0 in call to 'getpeername', should be 3
error: undefined symbol: htons
warning: To disable errors for undefined symbols use `-s ERROR_ON_UNDEFINED_SYMBOLS=0`
Error: Aborting compilation due to previous errors

(using -s ERROR_ON_UNDEFINED_SYMBOLS=0 as suggested would defeat the point of the config test :))

The behavior is triggered by using conftest.c as a file name.
It happens even without all the autoconf boilerplate.

See testcases attached.
conftests.zip

[kripken]

Thanks @Beuc! Fix in #9158

I see the same behavior regardless of the filename, though, it doesn't seem specific to conftest.c. Maybe I'm missing something? Does the PR work for you?

[Beuc]

Here's what I had with emsdk latest:

$ mv conftest.c conftest-getnameinfo.c
$ emcc -o conftest-getnameinfo    conftest-getnameinfo.c -ldl
[OK]

Since Emscripten has working test cases against getpeername/getnameinfo I thought this was specific to conftest.c. But admittedly this failed too :)

$ emcc -o conftest-getnameinfo.js    conftest-getnameinfo.c -ldl; echo $?
warning: unexpected number of arguments 0 in call to 'getnameinfo', should be 1
error: undefined symbol: htons
warning: To disable errors for undefined symbols use `-s ERROR_ON_UNDEFINED_SYMBOLS=0`
Error: Aborting compilation due to previous errors

The PR appears to work (correct results from Python ./configure) however there's still an error at runtime:

$ emcc -o conftest-getnameinfo.js    conftest-getnameinfo.c -ldl
warning: unexpected number of arguments 0 in call to 'getnameinfo', should be 1
$ node conftest-getnameinfo.js
exception thrown: ReferenceError: _ntohs is not defined,ReferenceError: _ntohs is not defined

[kripken]

Thanks, yeah, some more deps were needed, I added those now.

In general the sockets code is not well tested - just not many people use it, and our test suite is very minimal there.

[Beuc]

Looks like it works, thanks!