| Message ID | ZcsmdzB5Z0cVB+0B@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | pretty-print: Fix up ptrdiff handling for %tu, %to, %tx | expand |
On 2/13/24 01:21, Jakub Jelinek wrote: > Hi! > > 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. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > 2024-02-13 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. OK jeff
--- gcc/pretty-print.cc.jj 2024-02-12 12:44:09.344335964 +0100 +++ gcc/pretty-print.cc 2024-02-12 19:09:27.594483176 +0100 @@ -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)) \ --- gcc/fortran/error.cc.jj 2024-02-12 12:44:09.343335978 +0100 +++ gcc/fortran/error.cc 2024-02-12 19:11:23.564886530 +0100 @@ -886,13 +886,14 @@ error_print (const char *type, const cha 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);