Re: Error building run2 from source package in win7

[Charles Wilson <cygwin@cwilson.fastmail.fm>]

On 5/23/2011 1:22 PM, Eric Blake wrote:
> On 05/23/2011 11:17 AM, David Sastre wrote:
>> cc1: warnings being treated as errors
>> /usr/src/run2-0.4.0-1-src/run2-0.4.0-1/src/run2-0.4.0/lib/util.c: In function 'run2_strtol':
>> /usr/src/run2-0.4.0-1-src/run2-0.4.0-1/src/run2-0.4.0/lib/util.c:423:3: error: passing argument 3 of '__assert_func' discards qualifiers from pointer target type
>> /usr/include/assert.h:41:6: note: expected 'char *' but argument is of type 'const char *'
> 
> The signature in assert.h uses 'const char *'; I would have to suspect
> that somewhere in your build process you have a stray:
> 
> #define const
> 
> getting in the way,

I think this is the only possibility, because...

> and that this is thus a bug in the run2 sources and
> not in cygwin headers.

...the code does this:

int
run2_strtol(char *arg, long *value)
{
  char *endptr;
  int errno_save = errno;

  assert(arg!=NULL);

However, the stringization of the expression 'arg!=NULL' is passed as
arg #4 (and the expression itself doesn't appear in the argument list of
__assert_func at all; see definition below).  Anyway, the #3 argument of
__assert_func is __ASSERT_FUNC:

# define assert(__e) ((__e) ? (void)0 : \
   __assert_func (__FILE__, __LINE__, \
   __ASSERT_FUNC, #__e))

and __ASSERT_FUNC is defined as
	__PRETTY_FUNCTION__
	__func__
or 	__FUNCTION__
depending on the compiler and various flags.  Now, since these are
built-ins, the "signature" is fixed: they are all const char*.  So the
only way you could get this warning/error is if assert.h is "messed up"
somehow...e.g. as Eric suggests, because an earlier header has #defined
const away before the following decl in assert.h is parsed:

void _EXFUN(__assert_func, (const char *, int, const char *,
  const char *) _ATTRIBUTE ((__noreturn__)));




Now, where could a #define const occur?

$ find ${run2_srcdir} -type f |\
      xargs grep const | grep define | grep '#'
./configure:$as_echo "#define const /**/" >>confdefs.h

...more checking...Ah, this is part of the configure macro AC_C_CONST.

hmm...maybe the OP should check his generated config.h file for the
offending def.  If it's there, a quick look inside config.log should
tell you why 'checking for an ANSI C-conforming const' is reporting 'no'.

--
Chuck

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