[MacPorts] #71560: exim fails to build: exim.h: error: unknown type name 'res_state'

[MacPorts]

#71560: exim fails to build: exim.h: error: unknown type name 'res_state'
---------------------------+--------------------
  Reporter:  barracuda156  |      Owner:  (none)
      Type:  defect        |     Status:  new
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:  2.10.5
Resolution:                |   Keywords:
      Port:  exim          |
---------------------------+--------------------

Comment (by ryandesign):

 Replying to [ticket:71560 barracuda156]:
 > Initially the build fails if Xcode gcc is used:
 > {{{
 > exim.h:438: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’
 before ‘os_get_dns_resolver_res’
 > macro_predef.c:84: error: ‘for’ loop initial declaration used outside
 C99 mode
 > }}}
 > The first error remains even if `-std=c99` flags is used

 That's not possible. Enabling C99 mode will resolve that problem. However,
 if you had tried to add this in `configure.cflags`, then I would guess
 that the build system doesn't honor CFLAGS or the Portifle hasn't been
 programmed to pass them along. (I see the Portfile uses a custom configure
 phase.) I see from a buildbot log, for example, that `-Os`, which should
 be used since it is in our default CFLAGS, is not present. So this bug
 needs to be solved first.

 > Modern gcc does not accept `-no-cpp-precomp`:
 > {{{
 > gcc-mp-14: error: unrecognized command-line option '-no-cpp-precomp'
 > }}}
 > So I removed that flag.

 Yes, gcc 2.95 is the last version where that flag did anything; it should
 be removed.

 https://www.mistys-internet.website/blog/blog/2013/10/19/no-cpp-precomp-
 the-compiler-flag-that-time-forgot/

 > Then the build still fails on this:
 > {{{
 > exim.h:438:1: error: unknown type name 'res_state'
 >   438 | res_state os_get_dns_resolver_res(void);
 >       | ^~~~~~~~~
 > }}}

 `res_state` should be defined in resolv.h. exim.h does include resolv.h on
 line 424 so I wouldn't expect this error.

-- 
Ticket URL: <https://trac.macports.org/ticket/71560#comment:1>
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