[GHC] #14784: RTS header files can't be used with a C++ compiler

[GHC]

#14784: RTS header files can't be used with a C++ compiler
-------------------------------------+-------------------------------------
           Reporter:  niteria        |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Runtime        |           Version:
  System                             |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 If you compile `m1.cpp`:

 {{{
 #include "Rts.h"
 int main(int argc, char** argv) {
 }
 }}}

 with:
 {{{
 g++ -g m1.cpp -std=c++11 -I includes/ -c
 }}}

 you get:

 {{{
 In file included from includes/Rts.h:29:0,
                  from m1.cpp:1:
 includes/Stg.h:29:3: error: #error __STDC_VERSION__ does not advertise C99
 or later
  # error __STDC_VERSION__ does not advertise C99 or later
    ^
 }}}

 It's not advertised anywhere that it should work, but it used to work.
 https://phabricator.haskell.org/D2045 is what introduced this check.

 Judging by https://stackoverflow.com/questions/48045243/ghc-gcc-compiler-
 issue-stdc-version-w-c99-from-stg-h-fails-for-every-packa, it affects GHC
 8.2 and later.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14784>
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