#include <locale.h>
-#ifdef _LIBC
- /* Guess whether integer division by zero raises signal SIGFPE.
- Set to 1 only if you know for sure. In case of doubt, set to 0. */
-# if defined __alpha__ || defined __arm__ || defined __i386__ \
- || defined __m68k__ || defined __s390x__
-# define INTDIV0_RAISES_SIGFPE 1
-# else
-# define INTDIV0_RAISES_SIGFPE 0
-# endif
-#endif
-#if !INTDIV0_RAISES_SIGFPE
-# include <signal.h>
-#endif
-
#if defined HAVE_SYS_PARAM_H || defined _LIBC
# include <sys/param.h>
#endif
const char *translation, size_t translation_len)
{
struct loaded_domain *domaindata = (struct loaded_domain *) domain->data;
+ struct eval_result result;
unsigned long int index;
const char *p;
- index = plural_eval (domaindata->plural, n);
- if (index >= domaindata->nplurals)
- /* This should never happen. It means the plural expression and the
- given maximum value do not match. */
+ result = plural_eval (domaindata->plural, n);
+ if (result.status != PE_OK)
+ /* The plural expression evaluation failed. */
index = 0;
+ else if (result.value >= domaindata->nplurals)
+ /* The plural expression and the given maximum value do not match. */
+ index = 0;
+ else
+ index = result.value;
/* Skip INDEX strings at TRANSLATION. */
p = translation;
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
+/* Written by Ulrich Drepper and Bruno Haible. */
+
#ifndef STATIC
#define STATIC static
#endif
-/* Evaluate the plural expression and return an index value. */
-STATIC
-unsigned long int
-plural_eval (const struct expression *pexp, unsigned long int n)
+/* While the bison parser is able to support expressions of a maximum depth
+ of YYMAXDEPTH = 10000, the runtime evaluation of a parsed plural expression
+ has a smaller maximum recursion depth.
+ If we did not limit the recursion depth, a program that just invokes
+ ngettext() on a thread other than the main thread could get a crash by
+ stack overflow in the following circumstances:
+ - On systems with glibc, after the stack size has been reduced,
+ e.g. on x86_64 systems after "ulimit -s 260".
+ This stack size is only sufficient for ca. 3919 recursions.
+ Cf. <https://unix.stackexchange.com/questions/620720/>
+ - On systems with musl libc, because there the thread stack size (for a
+ thread other than the main thread) by default is only 128 KB, see
+ <https://wiki.musl-libc.org/functional-differences-from-glibc.html#Thread-stack-size>.
+ - On AIX 7 systems, because there the thread stack size (for a thread
+ other than the main thread) by default is only 96 KB, see
+ <https://www.ibm.com/docs/en/aix/7.1?topic=programming-threads-library-options>.
+ This stack size is only sufficient for between 887 and 1363 recursions,
+ depending on the compiler and compiler optimization options.
+ A maximum depth of 100 is a large enough for all practical needs
+ and also small enough to avoid stack overflow even with small thread stack
+ sizes. */
+#ifndef EVAL_MAXDEPTH
+# define EVAL_MAXDEPTH 100
+#endif
+
+/* A shorthand that denotes a successful evaluation result with a value V. */
+#define OK(v) (struct eval_result) { .status = PE_OK, .value = (v) }
+
+/* Evaluates a plural expression PEXP for n=N, up to ALLOWED_DEPTH. */
+static struct eval_result
+plural_eval_recurse (const struct expression *pexp, unsigned long int n,
+ unsigned int allowed_depth)
{
+ if (allowed_depth == 0)
+ /* The allowed recursion depth is exhausted. */
+ return (struct eval_result) { .status = PE_STACKOVF };
+ allowed_depth--;
+
switch (pexp->nargs)
{
case 0:
switch (pexp->operation)
{
case var:
- return n;
+ return OK (n);
case num:
- return pexp->val.num;
+ return OK (pexp->val.num);
default:
break;
}
case 1:
{
/* pexp->operation must be lnot. */
- unsigned long int arg = plural_eval (pexp->val.args[0], n);
- return ! arg;
+ struct eval_result arg =
+ plural_eval_recurse (pexp->val.args[0], n, allowed_depth);
+ if (arg.status != PE_OK)
+ return arg;
+ return OK (! arg.value);
}
case 2:
{
- unsigned long int leftarg = plural_eval (pexp->val.args[0], n);
+ struct eval_result leftarg =
+ plural_eval_recurse (pexp->val.args[0], n, allowed_depth);
+ if (leftarg.status != PE_OK)
+ return leftarg;
if (pexp->operation == lor)
- return leftarg || plural_eval (pexp->val.args[1], n);
+ {
+ if (leftarg.value)
+ return OK (1);
+ struct eval_result rightarg =
+ plural_eval_recurse (pexp->val.args[1], n, allowed_depth);
+ if (rightarg.status != PE_OK)
+ return rightarg;
+ return OK (rightarg.value ? 1 : 0);
+ }
else if (pexp->operation == land)
- return leftarg && plural_eval (pexp->val.args[1], n);
+ {
+ if (!leftarg.value)
+ return OK (0);
+ struct eval_result rightarg =
+ plural_eval_recurse (pexp->val.args[1], n, allowed_depth);
+ if (rightarg.status != PE_OK)
+ return rightarg;
+ return OK (rightarg.value ? 1 : 0);
+ }
else
{
- unsigned long int rightarg = plural_eval (pexp->val.args[1], n);
+ struct eval_result rightarg =
+ plural_eval_recurse (pexp->val.args[1], n, allowed_depth);
+ if (rightarg.status != PE_OK)
+ return rightarg;
switch (pexp->operation)
{
case mult:
- return leftarg * rightarg;
+ return OK (leftarg.value * rightarg.value);
case divide:
-#if !INTDIV0_RAISES_SIGFPE
- if (rightarg == 0)
- raise (SIGFPE);
-#endif
- return leftarg / rightarg;
+ if (rightarg.value == 0)
+ return (struct eval_result) { .status = PE_INTDIV };
+ return OK (leftarg.value / rightarg.value);
case module:
-#if !INTDIV0_RAISES_SIGFPE
- if (rightarg == 0)
- raise (SIGFPE);
-#endif
- return leftarg % rightarg;
+ if (rightarg.value == 0)
+ return (struct eval_result) { .status = PE_INTDIV };
+ return OK (leftarg.value % rightarg.value);
case plus:
- return leftarg + rightarg;
+ return OK (leftarg.value + rightarg.value);
case minus:
- return leftarg - rightarg;
+ return OK (leftarg.value - rightarg.value);
case less_than:
- return leftarg < rightarg;
+ return OK (leftarg.value < rightarg.value);
case greater_than:
- return leftarg > rightarg;
+ return OK (leftarg.value > rightarg.value);
case less_or_equal:
- return leftarg <= rightarg;
+ return OK (leftarg.value <= rightarg.value);
case greater_or_equal:
- return leftarg >= rightarg;
+ return OK (leftarg.value >= rightarg.value);
case equal:
- return leftarg == rightarg;
+ return OK (leftarg.value == rightarg.value);
case not_equal:
- return leftarg != rightarg;
+ return OK (leftarg.value != rightarg.value);
default:
break;
}
case 3:
{
/* pexp->operation must be qmop. */
- unsigned long int boolarg = plural_eval (pexp->val.args[0], n);
- return plural_eval (pexp->val.args[boolarg ? 1 : 2], n);
+ struct eval_result boolarg =
+ plural_eval_recurse (pexp->val.args[0], n, allowed_depth);
+ if (boolarg.status != PE_OK)
+ return boolarg;
+ return plural_eval_recurse (pexp->val.args[boolarg.value ? 1 : 2], n,
+ allowed_depth);
}
}
/* NOTREACHED */
- return 0;
+ return (struct eval_result) { .status = PE_ASSERT };
}
+
+/* Evaluates a plural expression PEXP for n=N. */
+STATIC
+struct eval_result
+plural_eval (const struct expression *pexp, unsigned long int n)
+{
+ return plural_eval_recurse (pexp, n, EVAL_MAXDEPTH);
+}
+
+#undef OK
projects / thirdparty / glibc.git / commitdiff
