The gcc C compiler doesn't seem to be following the traditional
"right-then-left" rule when compiling function pointer prototypes.
For example, gcc properly considers this to be a valid prototype:
int (*count)( demo_counter * self, int count_amt );
, but it does not seem to recognize that the following is also a valid
prototype:
int count * ( demo_counter * self, int count_amt );
Following the traditional "right-then-left" rule, BOTH of these should be
parsed as: "count is a pointer to a function which accepts a demo_counter
pointer and an int and returns an int.". But the second one results in a
compilation error with gcc.
I'm sorry, but I have no idea what "Host triplet", "Target triplet" or "Build
triplet" might possibly mean. However, per your instructions, here is some
further information:
* I noticed the bug while working on Windows XP, service pack 3, using the
Cygwin gcc compiler. I have not tried to reproduce it on other platforms or
with other compilers.
* Output from the compiler, including gcc version information and compiler
flags, appears below:
C:\f_p_compile>echo %PROCESSOR_IDENTIFIER%
x86 Family 6 Model 15 Stepping 10, GenuineIntel
C:\f_p_compile>make -f makefile gcc_version
gcc --version
gcc (GCC) 4.3.2 20080827 (beta) 2
Copyright (C) 2008 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.
C:\f_p_compile>make -f makefile demo_counter_demo
gcc -Wall -g -std=c99 -save-temps -o demo_counter.o -c demo_counter.c
In file included from demo_counter.c:2:
demo_counter.h:17: error: expected ':', ',', ';', '}' or '__attribute__' before
'*' token
demo_counter.c: In function 'demo_counter_constructor':
demo_counter.c:17: error: 'demo_counter' has no member named 'count'
make: *** [demo_counter.o] Error 1
C:\f_p_compile>
* the .i file fills the remainder of this description:
# 1 "demo_counter.c"
# 1 "/cygdrive/c/Documents and Settings/djones/Desktop/d_string/f_p_compile//"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "demo_counter.c"
# 1 "demo_counter.h" 1
# 10 "demo_counter.h"
typedef struct demo_counter_proto demo_counter;
struct demo_counter_proto {
int m_count;
void (*destroy)( demo_counter *);
int count * ( demo_counter * self, int count_amt );
};
demo_counter * demo_counter_constructor();
# 2 "demo_counter.c" 2
# 1 "/usr/include/stdlib.h" 1 3 4
# 10 "/usr/include/stdlib.h" 3 4
# 1 "/usr/include/_ansi.h" 1 3 4
# 15 "/usr/include/_ansi.h" 3 4
# 1 "/usr/include/newlib.h" 1 3 4
# 16 "/usr/include/_ansi.h" 2 3 4
# 1 "/usr/include/sys/config.h" 1 3 4
# 1 "/usr/include/machine/ieeefp.h" 1 3 4
# 5 "/usr/include/sys/config.h" 2 3 4
# 167 "/usr/include/sys/config.h" 3 4
# 1 "/usr/include/cygwin/config.h" 1 3 4
# 168 "/usr/include/sys/config.h" 2 3 4
# 17 "/usr/include/_ansi.h" 2 3 4
# 11 "/usr/include/stdlib.h" 2 3 4
# 1 "/usr/lib/gcc/i686-pc-cygwin/4.3.2/include/stddef.h" 1 3 4
# 214 "/usr/lib/gcc/i686-pc-cygwin/4.3.2/include/stddef.h" 3 4
typedef unsigned int size_t;
# 326 "/usr/lib/gcc/i686-pc-cygwin/4.3.2/include/stddef.h" 3 4
typedef short unsigned int wchar_t;
# 15 "/usr/include/stdlib.h" 2 3 4
# 1 "/usr/include/sys/reent.h" 1 3 4
# 13 "/usr/include/sys/reent.h" 3 4
# 1 "/usr/include/_ansi.h" 1 3 4
# 14 "/usr/include/sys/reent.h" 2 3 4
# 1 "/usr/include/sys/_types.h" 1 3 4
# 12 "/usr/include/sys/_types.h" 3 4
# 1 "/usr/include/sys/lock.h" 1 3 4
# 14 "/usr/include/sys/lock.h" 3 4
typedef void *_LOCK_T;
# 44 "/usr/include/sys/lock.h" 3 4
void __cygwin_lock_init(_LOCK_T *);
void __cygwin_lock_init_recursive(_LOCK_T *);
void __cygwin_lock_fini(_LOCK_T *);
void __cygwin_lock_lock(_LOCK_T *);
int __cygwin_lock_trylock(_LOCK_T *);
void __cygwin_lock_unlock(_LOCK_T *);
# 13 "/usr/include/sys/_types.h" 2 3 4
typedef long _off_t;
__extension__ typedef long long _off64_t;
typedef int _ssize_t;
# 1 "/usr/lib/gcc/i686-pc-cygwin/4.3.2/include/stddef.h" 1 3 4
# 355 "/usr/lib/gcc/i686-pc-cygwin/4.3.2/include/stddef.h" 3 4
typedef unsigned int wint_t;
# 25 "/usr/include/sys/_types.h" 2 3 4
typedef struct
{
int __count;
union
{
wint_t __wch;
unsigned char __wchb[4];
} __value;
} _mbstate_t;
typedef _LOCK_T _flock_t;
typedef void *_iconv_t;
# 15 "/usr/include/sys/reent.h" 2 3 4
typedef unsigned long __ULong;
# 35 "/usr/include/sys/reent.h" 3 4
struct _reent;
struct _Bigint
{
struct _Bigint *_next;
int _k, _maxwds, _sign, _wds;
__ULong _x[1];
};
struct __tm
{
int __tm_sec;
int __tm_min;
int __tm_hour;
int __tm_mday;
int __tm_mon;
int __tm_year;
int __tm_wday;
int __tm_yday;
int __tm_isdst;
};
struct _on_exit_args {
void * _fnargs[32];
void * _dso_handle[32];
__ULong _fntypes;
__ULong _is_cxa;
};
# 87 "/usr/include/sys/reent.h" 3 4
struct _atexit {
struct _atexit *_next;
int _ind;
void (*_fns[32])(void);
struct _on_exit_args _on_exit_args;
};
# 103 "/usr/include/sys/reent.h" 3 4
struct __sbuf {
unsigned char *_base;
int _size;
};
typedef long _fpos_t;
typedef _off64_t _fpos64_t;
# 168 "/usr/include/sys/reent.h" 3 4
struct __sFILE {
unsigned char *_p;
int _r;
int _w;
short _flags;
short _file;
struct __sbuf _bf;
int _lbfsize;
void * _cookie;
_ssize_t __attribute__((__cdecl__)) (*_read) (struct _reent *, void *, char
*, int);
_ssize_t __attribute__((__cdecl__)) (*_write) (struct _reent *, void *, const
char *, int);
_fpos_t __attribute__((__cdecl__)) (*_seek) (struct _reent *, void *,
_fpos_t, int);
int __attribute__((__cdecl__)) (*_close) (struct _reent *, void *);
struct __sbuf _ub;
unsigned char *_up;
int _ur;
unsigned char _ubuf[3];
unsigned char _nbuf[1];
struct __sbuf _lb;
int _blksize;
int _offset;
struct _reent *_data;
_flock_t _lock;
};
struct __sFILE64 {
unsigned char *_p;
int _r;
int _w;
short _flags;
short _file;
struct __sbuf _bf;
int _lbfsize;
struct _reent *_data;
void * _cookie;
_ssize_t __attribute__((__cdecl__)) (*_read) (struct _reent *, void *, char
*, int);
_ssize_t __attribute__((__cdecl__)) (*_write) (struct _reent *, void *, const
char *, int);
_fpos_t __attribute__((__cdecl__)) (*_seek) (struct _reent *, void *,
_fpos_t, int);
int __attribute__((__cdecl__)) (*_close) (struct _reent *, void *);
struct __sbuf _ub;
unsigned char *_up;
int _ur;
unsigned char _ubuf[3];
unsigned char _nbuf[1];
struct __sbuf _lb;
int _blksize;
int _flags2;
_off64_t _offset;
_fpos64_t __attribute__((__cdecl__)) (*_seek64) (struct _reent *, void *,
_fpos64_t, int);
_flock_t _lock;
};
typedef struct __sFILE64 __FILE;
struct _glue
{
struct _glue *_next;
int _niobs;
__FILE *_iobs;
};
# 294 "/usr/include/sys/reent.h" 3 4
struct _rand48 {
unsigned short _seed[3];
unsigned short _mult[3];
unsigned short _add;
};
# 569 "/usr/include/sys/reent.h" 3 4
struct _reent
{
int _errno;
__FILE *_stdin, *_stdout, *_stderr;
int _inc;
char _emergency[25];
int _current_category;
const char *_current_locale;
int __sdidinit;
void __attribute__((__cdecl__)) (*__cleanup) (struct _reent *);
struct _Bigint *_result;
int _result_k;
struct _Bigint *_p5s;
struct _Bigint **_freelist;
int _cvtlen;
char *_cvtbuf;
union
{
struct
{
unsigned int _unused_rand;
char * _strtok_last;
char _asctime_buf[26];
struct __tm _localtime_buf;
int _gamma_signgam;
__extension__ unsigned long long _rand_next;
struct _rand48 _r48;
_mbstate_t _mblen_state;
_mbstate_t _mbtowc_state;
_mbstate_t _wctomb_state;
char _l64a_buf[8];
char _signal_buf[24];
int _getdate_err;
_mbstate_t _mbrlen_state;
_mbstate_t _mbrtowc_state;
_mbstate_t _mbsrtowcs_state;
_mbstate_t _wcrtomb_state;
_mbstate_t _wcsrtombs_state;
} _reent;
struct
{
unsigned char * _nextf[30];
unsigned int _nmalloc[30];
} _unused;
} _new;
struct _atexit *_atexit;
struct _atexit _atexit0;
void (**(_sig_func))(int);
struct _glue __sglue;
__FILE __sf[3];
};
# 803 "/usr/include/sys/reent.h" 3 4
extern struct _reent *_impure_ptr ;
extern struct _reent *const _global_impure_ptr ;
void _reclaim_reent (struct _reent *);
struct _reent * __attribute__((__cdecl__)) __getreent (void);
# 17 "/usr/include/stdlib.h" 2 3 4
# 1 "/usr/include/machine/stdlib.h" 1 3 4
# 17 "/usr/include/machine/stdlib.h" 3 4
char *mkdtemp (char *);
# 18 "/usr/include/stdlib.h" 2 3 4
# 1 "/usr/include/cygwin/stdlib.h" 1 3 4
# 14 "/usr/include/cygwin/stdlib.h" 3 4
# 1 "/usr/include/cygwin/wait.h" 1 3 4
# 15 "/usr/include/cygwin/stdlib.h" 2 3 4
const char *getprogname (void);
void setprogname (const char *);
# 24 "/usr/include/stdlib.h" 2 3 4
typedef struct
{
int quot;
int rem;
} div_t;
typedef struct
{
long quot;
long rem;
} ldiv_t;
# 57 "/usr/include/stdlib.h" 3 4
extern __attribute__((dllimport)) int __mb_cur_max;
void __attribute__((__cdecl__)) abort (void) __attribute__ ((noreturn));
int __attribute__((__cdecl__)) abs (int);
int __attribute__((__cdecl__)) atexit (void (*__func)(void));
double __attribute__((__cdecl__)) atof (const char *__nptr);
int __attribute__((__cdecl__)) atoi (const char *__nptr);
int __attribute__((__cdecl__)) _atoi_r (struct _reent *, const char *__nptr);
long __attribute__((__cdecl__)) atol (const char *__nptr);
long __attribute__((__cdecl__)) _atol_r (struct _reent *, const char *__nptr);
void * __attribute__((__cdecl__)) bsearch (const void * __key, const void *
__base, size_t __nmemb, size_t __size, int (* __attribute__((__cdecl__))
_compar) (const void *, const void *));
void * __attribute__((__cdecl__)) calloc (size_t __nmemb, size_t __size);
div_t __attribute__((__cdecl__)) div (int __numer, int __denom);
void __attribute__((__cdecl__)) exit (int __status) __attribute__ ((noreturn));
void __attribute__((__cdecl__)) free (void *);
char * __attribute__((__cdecl__)) getenv (const char *__string);
char * __attribute__((__cdecl__)) _getenv_r (struct _reent *, const char
*__string);
char * __attribute__((__cdecl__)) _findenv (const char *, int *);
char * __attribute__((__cdecl__)) _findenv_r (struct _reent *, const char *,
int *);
long __attribute__((__cdecl__)) labs (long);
ldiv_t __attribute__((__cdecl__)) ldiv (long __numer, long __denom);
void * __attribute__((__cdecl__)) malloc (size_t __size);
int __attribute__((__cdecl__)) mblen (const char *, size_t);
int __attribute__((__cdecl__)) _mblen_r (struct _reent *, const char *, size_t,
_mbstate_t *);
int __attribute__((__cdecl__)) mbtowc (wchar_t *, const char *, size_t);
int __attribute__((__cdecl__)) _mbtowc_r (struct _reent *, wchar_t *, const
char *, size_t, _mbstate_t *);
int __attribute__((__cdecl__)) wctomb (char *, wchar_t);
int __attribute__((__cdecl__)) _wctomb_r (struct _reent *, char *, wchar_t,
_mbstate_t *);
size_t __attribute__((__cdecl__)) mbstowcs (wchar_t *, const char *, size_t);
size_t __attribute__((__cdecl__)) _mbstowcs_r (struct _reent *, wchar_t *,
const char *, size_t, _mbstate_t *);
size_t __attribute__((__cdecl__)) wcstombs (char *, const wchar_t *, size_t);
size_t __attribute__((__cdecl__)) _wcstombs_r (struct _reent *, char *, const
wchar_t *, size_t, _mbstate_t *);
void __attribute__((__cdecl__)) qsort (void * __base, size_t __nmemb, size_t
__size, int(*_compar)(const void *, const void *));
int __attribute__((__cdecl__)) rand (void);
void * __attribute__((__cdecl__)) realloc (void * __r, size_t __size);
void __attribute__((__cdecl__)) srand (unsigned __seed);
double __attribute__((__cdecl__)) strtod (const char *__n, char **__end_PTR);
double __attribute__((__cdecl__)) _strtod_r (struct _reent *,const char *__n,
char **__end_PTR);
float __attribute__((__cdecl__)) strtof (const char *__n, char **__end_PTR);
long __attribute__((__cdecl__)) strtol (const char *__n, char **__end_PTR, int
__base);
long __attribute__((__cdecl__)) _strtol_r (struct _reent *,const char *__n,
char **__end_PTR, int __base);
unsigned long __attribute__((__cdecl__)) strtoul (const char *__n, char
**__end_PTR, int __base);
unsigned long __attribute__((__cdecl__)) _strtoul_r (struct _reent *,const char
*__n, char **__end_PTR, int __base);
int __attribute__((__cdecl__)) system (const char *__string);
# 183 "/usr/include/stdlib.h" 3 4
char * __attribute__((__cdecl__)) _dtoa_r (struct _reent *, double, int, int,
int *, int*, char**);
int __attribute__((__cdecl__)) _system_r (struct _reent *, const char *);
void __attribute__((__cdecl__)) __eprintf (const char *, const char *, unsigned
int, const char *);
# 5 "demo_counter.c" 2
static void demo_counter_destroy( demo_counter * self );
static int demo_counter_count( demo_counter * self, int count_amt );
demo_counter * demo_counter_constructor() {
demo_counter * p_fresh = malloc( sizeof( demo_counter ) );
if ( 0 != p_fresh ) {
p_fresh->m_count = 0;
p_fresh->destroy = demo_counter_destroy;
p_fresh->count = demo_counter_count;
}
return p_fresh;
}
static void demo_counter_destroy( demo_counter * self ) {
free( self );
}
static int demo_counter_count( demo_counter * self, int count_amt ) {
self->m_count += count_amt;
return self->m_count;
}
--
Summary: not following "right-then-left" rule when compiling
function pointers
Product: gcc
Version: 4.3.2
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dj2con at gmail dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40627
