Re: Bug#811707: FTBFS with GCC 6: compiler failed the ACC conformance test

[Robert Luberda <robert@debian.org>]

reassign 811707 gcc-6 6-20160228-1
retitle  811707 gcc-6 fails to compile a valid code
affects  811707 src:ucl
thanks

Martin Michlmayr pisze:

> This package fails to build with GCC 6.  GCC 6 has not been released
> yet, but it's expected that GCC 6 will become the default compiler for
> stretch.


In my opinion this is gcc-6 fault, that can be easily reproduced:

/tmp> cat test.c

extern int __acc_cta[1-2*!((1l << (8*4 -1)) < 0)];


/tmp> gcc-6 -c test.c
test.c:2:12: error: variably modified __acc_cta at file scope
 extern int __acc_cta[1-2*!((1l << (8*4 -1)) < 0)];
            ^~~~~~~~~
/tmp> gcc-6 --version
gcc-6 (Debian 6-20160228-1) 6.0.0 20160228 (experimental) [trunk
revision 233789]
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


> checking whether your compiler passes the ACC conformance test... FAILED
> configure:
> configure: Your compiler failed the ACC conformance test - for details
see
> configure: `config.log'. Please check that log file and consider sending

Just in case - the actual errors from config.log were:

In file included from ../acc/acc.h:78:0, from conftest.c:113:
../acc/acc_defs.h:97:59: error: variably modified '__acc_cta' at file scope
# define ACC_COMPILE_TIME_ASSERT_HEADER(e) extern int _acc_cta[1-2*!(e)];
^
conftest.c:116:33: note: in expansion of macro
'ACC_COMPILE_TIME_ASSERT_HEADER'
#define ACCCHK_ASSERT(expr) ACC_COMPILE_TIME_ASSERT_HEADER(expr)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../acc/acc_chk.ch:212:5: note: in expansion of macro 'ACCCHK_ASSERT'
ACCCHK_ASSERT((1l << (8*SIZEOF_LONG-1)) < 0)


Regards,
robert