[Swan-dev] odd error only on ppc64 on rhel6

[D. Hugh Redelmeier]

| From: Antony Antony <antony at phenome.org>

| which flag do you mean? the actual flag seems to be lost? Atleast I can't 
| find it. 

The problem is that the mail was private.  But not for any good
reason.  At my urging, it became public halfway through.  Confusing.

| There was an earlier discussion
| https://lists.libreswan.org/pipermail/swan-dev/2019-May/003226.html
| As re-collect you wrote "-Wno-missing-field-initializers" is not a good 
| idea?

That was about mk/docker.mk.  As far as I understand that's not
involved with our problem (based soley on its filename).

I was trying to say that we don't want -Wmissing-field-initializers
(in this case).

In the split thread, I'm trying to say that we DO want
	-Wno-missing-field-initializers
This is a flag with the opposite meaning.

I will note that Tuomo recommended this same flag on the mailing list 2018 
November 16.  I'm sad that I had to rediscover this flag.  Somebody should 
have checked it into our tree back then.

| It is in docker-targets.mk, which is used by travis testing make scripts.
| I think, I added it to compile on CentOS6 and I didn't really understand 
| what I am doing:) However, CentOS is broken [1]

The flag -Wmissing-field-initializers can only cause failures.  It won't 
fix failures.  That would be good if the missing initializer were a
mistake.  But we intentionally write code with missing initializers.
(I will admit that, in some cases, missing initializers are a bug.)

-Wno-missing-field-initializers can only suppress failures, it won't
cause failures.

| NOTE:
| We have travis that compile #master on various distributions.

Good!

| The scripts and hooks to compile on various distributions, on your own 
| server are in the master.
| I guess a better writeup about this would be nicer! Currently it is hidden 
| in docker test suite documentation, only semi automized.

Better documentation is always a Good Idea.  Then comes convincing
people to read it.

| I am curious about initializer issue because it has been taking too much 
| time from me. My guess is other people on the list are also confused about 
| it. May be one alternative is we decie not to support CentOS6?

This is a solved problem since last November.  Too bad we didn't adopt
the solution.

| PS: googling about -Wno-missing-field-initializers pointed me to 1998 
| references, see  the links in the second message on this thread.
| https://stackoverflow.com/questions/1538943/why-is-the-compiler-throwing-this-warning-missing-initializer-isnt-the-stru

Yeah.  I included that link in the pointlessly private part of this 
thread.

| Paul: the initializer issue is not a one line change. Once you fix the one 
| you noticed, more warnings like that will show up.

That's what I guessed.  But I didn't know that I had tools with which to 
test for it and assumed those with the problem would do the legwork.

| [1]
| https://travis-ci.org/antonyantony/libreswan/builds/546142308
| /home/build/libreswan/lib/libswan/addr_lookup.c:67:6: error: implicit declaration of function 'printf' [-Werror=implicit-function-declaration]
|       printf("found peer %s to interface %s\n",

Interesting.

1) this probably deserves its own thread.  It may not be noticed at the 
   bottom of an unrelated message.

2) I just did
	git pull
	make clean
	make base
   and did not observe this.  Perhaps it is fixed?