procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

pretty-print: Fix up ptrdiff handling for %tu, %to, %tx

Browse source 
This is IMHO more of a theoretical case, I believe my current code
doesn't handle %tu or %to or %tx correctly if ptrdiff_t is not one of
int, long int or long long int.  For size_t and %zd or %zi I'm
using va_arg (whatever, ssize_t) and hope that ssize_t is the signed
type corresponding to size_t which C99 talks about.
For ptrdiff_t there is no type for unsigned type corresponding to
ptrdiff_t and I'm not aware of a portable way on the host to get
such a type (the fmt tests use hacks like
 #define signed /* Type might or might not have explicit 'signed'.  */
 typedef unsigned __PTRDIFF_TYPE__ unsigned_ptrdiff_t;
 #undef signed
but that only works with compilers which predefine __PTRDIFF_TYPE__),
std::make_unsigned<ptrdiff_t> I believe only works reliably if
ptrdiff_t is one of char, signed char, short, int, long or long long,
but won't work e.g. for __int20__ or whatever other weird ptrdiff_t
the host might have.

The following patch assumes host is two's complement (I think we
rely on it pretty much everywhere anyway) and prints unsigned type
corresponding to ptrdiff_t as unsigned long long printing of
ptrdiff_t value masked with 2ULL * PTRDIFF_MAX + 1.  So the only
actual limitation is that it doesn't support ptrdiff_t wider than
long long int.

2024-02-14  Jakub Jelinek  <jakub@redhat.com>

	* pretty-print.cc (PTRDIFF_MAX): Define if not yet defined.
	(pp_integer_with_precision): For unsigned ptrdiff_t printing
	with u, o or x print ptrdiff_t argument converted to
	unsigned long long and masked with 2ULL * PTRDIFF_MAX + 1.

	* error.cc (error_print): For u printing of ptrdiff_t,
	print ptrdiff_t argument converted to unsigned long long and
	masked with 2ULL * PTRDIFF_MAX + 1.
This commit is contained in:
Jakub Jelinek 2024-02-14 14:35:32 +01:00
parent 5352ede924
commit e8971ef995
2 changed files with 20 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
gcc/fortran/error.cc
View file

@ -886,13 +886,14 @@ error_print (const char *type, const char *format0, va_list argp)
format++;
if (*format == 'u')
{
ptrdiff_t ptrdiffval = spec[n++].u.ptrdiffval;
if (sizeof (ptrdiff_t) == sizeof (int))
error_uinteger ((unsigned) ptrdiffval);
else if (sizeof (ptrdiff_t) == sizeof (long))
error_uinteger ((unsigned long) ptrdiffval);
else
error_uinteger (ptrdiffval);
unsigned long long a = spec[n++].u.ptrdiffval, m;
#ifdef PTRDIFF_MAX
m = PTRDIFF_MAX;
#else
m = INTTYPE_MAXIMUM (ptrdiff_t);
#endif
m = 2 * m + 1;
error_uinteger (a & m);
}
else
error_integer (spec[n++].u.ptrdiffval);

13
gcc/pretty-print.cc
View file

@ -752,6 +752,9 @@ output_buffer::~output_buffer ()
obstack_free (&formatted_obstack, NULL);
}
#ifndef PTRDIFF_MAX
#define PTRDIFF_MAX INTTYPE_MAXIMUM (ptrdiff_t)
#endif
/* Format an integer given by va_arg (ARG, type-specifier T) where
type-specifier is a precision modifier as indicated by PREC. F is
@ -783,7 +786,15 @@ output_buffer::~output_buffer ()
break; \
\
case 4: \
if (sizeof (ptrdiff_t) <= sizeof (int)) \
if (T (-1) >= T (0)) \
{ \
unsigned long long a = va_arg (ARG, ptrdiff_t); \
unsigned long long m = PTRDIFF_MAX; \
m = 2 * m + 1; \
pp_scalar (PP, "%" HOST_LONG_LONG_FORMAT F, \
a & m); \
} \
else if (sizeof (ptrdiff_t) <= sizeof (int)) \
pp_scalar (PP, "%" F, \
(int) va_arg (ARG, ptrdiff_t)); \
else if (sizeof (ptrdiff_t) <= sizeof (long)) \