Re: [Mingw-users] Building pthread using Lee's draft on how to rebuild ....

[Stephen L. <sld...@so...>]

Eduardo,

You had the same error before and did the 'right thing' to get rid of it:

> >> Ok. so I did the right thing and error msg changed.  Now gcc is missing
> >> sys/wait.h when compiling libiberty/pex_win32.c

So what has changed?

> > I removed everything from /develop/build and restarted there.
> > Unfortunately it didn't end up well.  See the errors below.
> >
> > ../../gcc-4.2.1-2-src/libiberty/objalloc.c: In function `objalloc_create':
> > ../../gcc-4.2.1-2-src/libiberty/objalloc.c:106: warning: implicit
> > declaration of function `__builtin_offsetof'
> > ../../gcc-4.2.1-2-src/libiberty/objalloc.c:106: error: parse error
> > before "struct"

This came from the line

  ret->current_ptr = (char *) chunk + CHUNK_HEADER_SIZE;

where CHUNK_HEADER_SIZE is

#define CHUNK_HEADER_SIZE					\
  ((sizeof (struct objalloc_chunk) + OBJALLOC_ALIGN - 1)	\
   &~ (OBJALLOC_ALIGN - 1))

You can find OBJALLOC_ALIGN in include/objalloc.h:

/* Work out the required alignment.  */

struct objalloc_align { char x; double d; };

#if defined (__STDC__) && __STDC__
#ifndef offsetof
#include <stddef.h>
#endif
#endif
#ifndef offsetof
#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
#endif
#define OBJALLOC_ALIGN offsetof (struct objalloc_align, d)

Now, the way you got to __builtin_offsetof is by the stddef.h include,
and as the name suggests, it is a gcc builtin so I don't see why it is
complaining.

Presumably, in the same compile environment everything that includes
<stddef.h> and uses offsetof will break in the same way.  Why don't
you try to write a small test program and see if you can reproduce the
error?  It should help you figure out what is wrong.

-- 
Stephen Lee <sld...@so...>