+#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
+
+
+/* Range overflow checks.
+
+ The INT_<op>_RANGE_OVERFLOW macros return 1 if the corresponding C
+ operators might not yield numerically correct answers due to
+ arithmetic overflow. They do not rely on undefined or
+ implementation-defined behavior. Their implementations are simple
+ and straightforward, but they are a bit harder to use than the
+ INT_<op>_OVERFLOW macros described below.
+
+ Example usage:
+
+ long int i = ...;
+ long int j = ...;
+ if (INT_MULTIPLY_RANGE_OVERFLOW (i, j, LONG_MIN, LONG_MAX))
+ printf ("multiply would overflow");
+ else
+ printf ("product is %ld", i * j);
+
+ Restrictions on *_RANGE_OVERFLOW macros:
+
+ These macros do not check for all possible numerical problems or
+ undefined or unspecified behavior: they do not check for division
+ by zero, for bad shift counts, or for shifting negative numbers.
+
+ These macros may evaluate their arguments zero or multiple times,
+ so the arguments should not have side effects. The arithmetic
+ arguments (including the MIN and MAX arguments) must be of the same
+ integer type after the usual arithmetic conversions, and the type
+ must have minimum value MIN and maximum MAX. Unsigned types should
+ use a zero MIN of the proper type.
+
+ These macros are tuned for constant MIN and MAX. For commutative
+ operations such as A + B, they are also tuned for constant B. */
+
+/* Return 1 if A + B would overflow in [MIN,MAX] arithmetic.
+ See above for restrictions. */
+#define INT_ADD_RANGE_OVERFLOW(a, b, min, max) \
+ ((b) < 0 \
+ ? (a) < (min) - (b) \
+ : (max) - (b) < (a))
+
+/* Return 1 if A - B would overflow in [MIN,MAX] arithmetic.
+ See above for restrictions. */
+#define INT_SUBTRACT_RANGE_OVERFLOW(a, b, min, max) \
+ ((b) < 0 \
+ ? (max) + (b) < (a) \
+ : (a) < (min) + (b))
+
+/* Return 1 if - A would overflow in [MIN,MAX] arithmetic.
+ See above for restrictions. */
+#define INT_NEGATE_RANGE_OVERFLOW(a, min, max) \
+ ((min) < 0 \
+ ? (a) < - (max) \
+ : 0 < (a))
+
+/* Return 1 if A * B would overflow in [MIN,MAX] arithmetic.
+ See above for restrictions. Avoid && and || as they tickle
+ bugs in Sun C 5.11 2010/08/13 and other compilers; see
+ <http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00401.html>. */
+#define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max) \
+ ((b) < 0 \
+ ? ((a) < 0 \
+ ? (a) < (max) / (b) \
+ : (b) == -1 \
+ ? 0 \
+ : (min) / (b) < (a)) \
+ : (b) == 0 \
+ ? 0 \
+ : ((a) < 0 \
+ ? (a) < (min) / (b) \
+ : (max) / (b) < (a)))
+
+/* Return 1 if A / B would overflow in [MIN,MAX] arithmetic.
+ See above for restrictions. Do not check for division by zero. */
+#define INT_DIVIDE_RANGE_OVERFLOW(a, b, min, max) \
+ ((min) < 0 && (b) == -1 && (a) < - (max))
+
+/* Return 1 if A % B would overflow in [MIN,MAX] arithmetic.
+ See above for restrictions. Do not check for division by zero.
+ Mathematically, % should never overflow, but on x86-like hosts
+ INT_MIN % -1 traps, and the C standard permits this, so treat this
+ as an overflow too. */
+#define INT_REMAINDER_RANGE_OVERFLOW(a, b, min, max) \
+ INT_DIVIDE_RANGE_OVERFLOW (a, b, min, max)
+
+/* Return 1 if A << B would overflow in [MIN,MAX] arithmetic.
+ See above for restrictions. Here, MIN and MAX are for A only, and B need
+ not be of the same type as the other arguments. The C standard says that
+ behavior is undefined for shifts unless 0 <= B < wordwidth, and that when
+ A is negative then A << B has undefined behavior and A >> B has
+ implementation-defined behavior, but do not check these other
+ restrictions. */
+#define INT_LEFT_SHIFT_RANGE_OVERFLOW(a, b, min, max) \
+ ((a) < 0 \
+ ? (a) < (min) >> (b) \
+ : (max) >> (b) < (a))
+
+
+/* The _GL*_OVERFLOW macros have the same restrictions as the
+ *_RANGE_OVERFLOW macros, except that they do not assume that operands
+ (e.g., A and B) have the same type as MIN and MAX. Instead, they assume
+ that the result (e.g., A + B) has that type. */
+#define _GL_ADD_OVERFLOW(a, b, min, max) \
+ ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max) \
+ : (a) < 0 ? (b) <= (a) + (b) \
+ : (b) < 0 ? (a) <= (a) + (b) \
+ : (a) + (b) < (b))
+#define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \
+ ((min) < 0 ? INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max) \
+ : (a) < 0 ? 1 \
+ : (b) < 0 ? (a) - (b) <= (a) \
+ : (a) < (b))
+#define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \
+ (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a)))) \
+ || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max))
+#define _GL_DIVIDE_OVERFLOW(a, b, min, max) \
+ ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \
+ : (a) < 0 ? (b) <= (a) + (b) - 1 \
+ : (b) < 0 && (a) + (b) <= (a))
+#define _GL_REMAINDER_OVERFLOW(a, b, min, max) \
+ ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \
+ : (a) < 0 ? (a) % (b) != ((max) - (b) + 1) % (b) \
+ : (b) < 0 && ! _GL_UNSIGNED_NEG_MULTIPLE (a, b, max))
+
+/* Return a nonzero value if A is a mathematical multiple of B, where
+ A is unsigned, B is negative, and MAX is the maximum value of A's
+ type. A's type must be the same as (A % B)'s type. Normally (A %
+ -B == 0) suffices, but things get tricky if -B would overflow. */
+#define _GL_UNSIGNED_NEG_MULTIPLE(a, b, max) \
+ (((b) < -_GL_SIGNED_INT_MAXIMUM (b) \
+ ? (_GL_SIGNED_INT_MAXIMUM (b) == (max) \
+ ? (a) \
+ : (a) % (_GL_INT_CONVERT (a, _GL_SIGNED_INT_MAXIMUM (b)) + 1)) \
+ : (a) % - (b)) \
+ == 0)
+
+
+/* Integer overflow checks.
+
+ The INT_<op>_OVERFLOW macros return 1 if the corresponding C operators
+ might not yield numerically correct answers due to arithmetic overflow.
+ They work correctly on all known practical hosts, and do not rely
+ on undefined behavior due to signed arithmetic overflow.
+
+ Example usage:
+
+ long int i = ...;
+ long int j = ...;
+ if (INT_MULTIPLY_OVERFLOW (i, j))
+ printf ("multiply would overflow");
+ else
+ printf ("product is %ld", i * j);
+
+ These macros do not check for all possible numerical problems or
+ undefined or unspecified behavior: they do not check for division
+ by zero, for bad shift counts, or for shifting negative numbers.
+
+ These macros may evaluate their arguments zero or multiple times, so the
+ arguments should not have side effects.
+
+ These macros are tuned for their last argument being a constant.
+
+ Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B,
+ A % B, and A << B would overflow, respectively. */
+
+#define INT_ADD_OVERFLOW(a, b) \
+ _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW)
+#define INT_SUBTRACT_OVERFLOW(a, b) \
+ _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW)
+#define INT_NEGATE_OVERFLOW(a) \
+ INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a))
+#define INT_MULTIPLY_OVERFLOW(a, b) \
+ _GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW)
+#define INT_DIVIDE_OVERFLOW(a, b) \
+ _GL_BINARY_OP_OVERFLOW (a, b, _GL_DIVIDE_OVERFLOW)
+#define INT_REMAINDER_OVERFLOW(a, b) \
+ _GL_BINARY_OP_OVERFLOW (a, b, _GL_REMAINDER_OVERFLOW)
+#define INT_LEFT_SHIFT_OVERFLOW(a, b) \
+ INT_LEFT_SHIFT_RANGE_OVERFLOW (a, b, \
+ _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a))
+
+/* Return 1 if the expression A <op> B would overflow,
+ where OP_RESULT_OVERFLOW (A, B, MIN, MAX) does the actual test,
+ assuming MIN and MAX are the minimum and maximum for the result type.
+ Arguments should be free of side effects. */
+#define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow) \
+ op_result_overflow (a, b, \
+ _GL_INT_MINIMUM (0 * (b) + (a)), \
+ _GL_INT_MAXIMUM (0 * (b) + (a)))