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Port --fcheck-pointer-bounds to --with-wide-int

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* src/lisp (XSYMBOL) [__CHKP__ && !USE_LSB_TAG]:
Bypass pointer bounds checking here,
instead of failing the entire build.
(make_lisp_symbol): Improve comment.
This commit is contained in:
Paul Eggert 2017-12-12 12:59:27 -08:00
parent 4295050e11
commit e921f97df9
1 changed files with 10 additions and 5 deletions
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15
src/lisp.h
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@ -902,12 +902,15 @@ INLINE struct Lisp_Symbol *
{
#if USE_LSB_TAG
return lisp_h_XSYMBOL (a);
#elif defined __CHKP__
# error "pointer-checking not supported with wide integers"
#else
eassert (SYMBOLP (a));
intptr_t i = (intptr_t) XUNTAG (a, Lisp_Symbol);
void *p = (char *) lispsym + i;
# ifdef __CHKP__
/* Bypass pointer checking. Although this could be improved it is
probably not worth the trouble. */
p = __builtin___bnd_set_ptr_bounds (p, sizeof (struct Lisp_Symbol));
# endif
return p;
#endif
}
@ -916,9 +919,11 @@ INLINE Lisp_Object
make_lisp_symbol (struct Lisp_Symbol *sym)
{
#ifdef __CHKP__
/* Although this should use '__builtin___bnd_narrow_ptr_bounds (sym,
sym, sizeof *sym)', that would run afoul of GCC bug 83251
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83251>. */
/* Although '__builtin___bnd_narrow_ptr_bounds (sym, sym, sizeof *sym)'
should be more efficient, it runs afoul of GCC bug 83251
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83251>.
Also, attempting to call __builtin___bnd_chk_ptr_bounds (sym, sizeof *sym)
here seems to trigger a GCC bug, as yet undiagnosed. */
char *addr = __builtin___bnd_set_ptr_bounds (sym, sizeof *sym);
char *symoffset = addr - (intptr_t) lispsym;
#else