Set error codes for truncating int conversions

json_object_get_int/int64/uint64() now sets errno to ERANGE when the source value
can't be represented in the target type.

json_object.c

@@ -757,17 +757,29 @@ int32_t json_object_get_int(const struct json_object *jso)
 	{
 	case json_type_int:
 		/* Make sure we return the correct values for out of range numbers. */
-		if (cint64 <= INT32_MIN)
+		if (cint64 < INT32_MIN)
+		{
+			errno = ERANGE;
 			return INT32_MIN;
-		if (cint64 >= INT32_MAX)
+		}
+		if (cint64 > INT32_MAX)
+		{
+			errno = ERANGE;
 			return INT32_MAX;
+		}
 		return (int32_t)cint64;
 	case json_type_double:
 		cdouble = JC_DOUBLE_C(jso)->c_double;
-		if (cdouble <= INT32_MIN)
+		if (cdouble < INT32_MIN)
+		{
+			errno = ERANGE;
 			return INT32_MIN;
-		if (cdouble >= INT32_MAX)
+		}
+		if (cdouble > INT32_MAX)
+		{
+			errno = ERANGE;
 			return INT32_MAX;
+		}
 		if (isnan(cdouble))
 		{
 			errno = EINVAL;
@@ -820,8 +832,11 @@ int64_t json_object_get_int64(const struct json_object *jso)
 		{
 		case json_object_int_type_int64: return jsoint->cint.c_int64;
 		case json_object_int_type_uint64:
-			if (jsoint->cint.c_uint64 >= INT64_MAX)
+			if (jsoint->cint.c_uint64 > INT64_MAX)
+			{
+				errno = ERANGE;
 				return INT64_MAX;
+			}
 			return (int64_t)jsoint->cint.c_uint64;
 		default: json_abort("invalid cint_type");
 		}
@@ -829,10 +844,16 @@ int64_t json_object_get_int64(const struct json_object *jso)
 	case json_type_double:
 		// INT64_MAX can't be exactly represented as a double
 		// so cast to tell the compiler it's ok to round up.
-		if (JC_DOUBLE_C(jso)->c_double >= (double)INT64_MAX)
+		if (JC_DOUBLE_C(jso)->c_double > (double)INT64_MAX)
+		{
+			errno = ERANGE;
 			return INT64_MAX;
-		if (JC_DOUBLE_C(jso)->c_double <= INT64_MIN)
+		}
+		if (JC_DOUBLE_C(jso)->c_double < (double)INT64_MIN)
+		{
+			errno = ERANGE;
 			return INT64_MIN;
+		}
 		if (isnan(JC_DOUBLE_C(jso)->c_double))
 		{
 			errno = EINVAL;
@@ -864,7 +885,10 @@ uint64_t json_object_get_uint64(const struct json_object *jso)
 		{
 		case json_object_int_type_int64:
 			if (jsoint->cint.c_int64 < 0)
+			{
+				errno = ERANGE;
 				return 0;
+			}
 			return (uint64_t)jsoint->cint.c_int64;
 		case json_object_int_type_uint64: return jsoint->cint.c_uint64;
 		default: json_abort("invalid cint_type");
@@ -873,10 +897,16 @@ uint64_t json_object_get_uint64(const struct json_object *jso)
 	case json_type_double:
 		// UINT64_MAX can't be exactly represented as a double
 		// so cast to tell the compiler it's ok to round up.
-		if (JC_DOUBLE_C(jso)->c_double >= (double)UINT64_MAX)
+		if (JC_DOUBLE_C(jso)->c_double > (double)UINT64_MAX)
+		{
+			errno = ERANGE;
 			return UINT64_MAX;
+		}
 		if (JC_DOUBLE_C(jso)->c_double < 0)
+		{
+			errno = ERANGE;
 			return 0;
+		}
 		if (isnan(JC_DOUBLE_C(jso)->c_double))
 		{
 			errno = EINVAL;

json_object.h

@@ -743,7 +743,8 @@ JSON_EXPORT struct json_object *json_object_new_uint64(uint64_t i);
  * which return INT32_MIN and the errno is set to EINVAL.
  * Strings will be parsed as an integer. If no conversion exists then 0 is
  * returned and errno is set to EINVAL. null is equivalent to 0 (no error values
- * set)
+ * set).
+ * Sets errno to ERANGE if the value exceeds the range of int.
  *
  * Note that integers are stored internally as 64-bit values.
  * If the value of too big or too small to fit into 32-bit, INT32_MAX or
@@ -789,7 +790,8 @@ JSON_EXPORT int json_object_int_inc(struct json_object *obj, int64_t val);
  * which return INT64_MIN and the errno is set to EINVAL.
  * Strings will be parsed as an int64. If no conversion exists then 0 is
  * returned and errno is set to EINVAL. null is equivalent to 0 (no error values
- * set)
+ * set).
+ * Sets errno to ERANGE if the value exceeds the range of int64.
  *
  * NOTE: Set errno to 0 directly before a call to this function to determine
  * whether or not conversion was successful (it does not clear the value for
@@ -807,7 +809,8 @@ JSON_EXPORT int64_t json_object_get_int64(const struct json_object *obj);
  * which return 0 and the errno is set to EINVAL.
  * Strings will be parsed as an uint64. If no conversion exists then 0 is
  * returned and errno is set to EINVAL. null is equivalent to 0 (no error values
- * set)
+ * set).
+ * Sets errno to ERANGE if the value exceeds the range of uint64.
  *
  * NOTE: Set errno to 0 directly before a call to this function to determine
  * whether or not conversion was successful (it does not clear the value for

tests/test_int_get.c

@@ -8,6 +8,8 @@
 
 #include "json.h"
 
+#define I32_MAX_S "2147483647"
+#define I32_MIN_S "-2147483648"
 #define I64_MAX_S "9223372036854775807"
 #define I64_OVER  "9223372036854775808"
 #define I64_MIN_S "-9223372036854775808"
@@ -43,12 +45,15 @@ int main(int argc, char **argv)
 
 	CHECK_GET_INT(N_I64(INT32_MAX), INT32_MAX && errno == 0);
 	CHECK_GET_INT(N_I64(INT32_MIN), INT32_MIN && errno == 0);
-	CHECK_GET_INT(N_I64(INT64_MAX), INT32_MAX && errno == 0);
-	CHECK_GET_INT(N_I64(INT64_MIN), INT32_MIN && errno == 0);
-	CHECK_GET_INT(N_STR(I64_MAX_S), INT32_MAX && errno == 0);
-	CHECK_GET_INT(N_STR(I64_MIN_S), INT32_MIN && errno == 0);
+	CHECK_GET_INT(N_I64(INT64_MAX), INT32_MAX && errno == ERANGE);
+	CHECK_GET_INT(N_I64(INT64_MIN), INT32_MIN && errno == ERANGE);
+	CHECK_GET_INT(N_STR(I32_MAX_S), INT32_MAX && errno == 0);
+	CHECK_GET_INT(N_STR(I32_MIN_S), INT32_MIN && errno == 0);
+	CHECK_GET_INT(N_STR(I64_MAX_S), INT32_MAX && errno == ERANGE);
+	CHECK_GET_INT(N_STR(I64_MIN_S), INT32_MIN && errno == ERANGE);
+	CHECK_GET_INT(N_DBL(INFINITY),  INT32_MAX && errno == ERANGE);
+	CHECK_GET_INT(N_DBL(-INFINITY), INT32_MIN && errno == ERANGE);
 	CHECK_GET_INT(N_DBL(NAN),       INT32_MIN && errno == EINVAL);
-
 	printf("INT GET PASSED\n");
 
 	CHECK_GET_INT64(N_I64(INT64_MAX), INT64_MAX && errno == 0);
@@ -57,12 +62,16 @@ int main(int argc, char **argv)
 	CHECK_GET_INT64(N_STR(I64_MIN_S), INT64_MIN && errno == 0);
 	CHECK_GET_INT64(N_STR(I64_OVER),  INT64_MAX && errno == ERANGE);
 	CHECK_GET_INT64(N_STR(I64_UNDER), INT64_MIN && errno == ERANGE);
+	CHECK_GET_INT64(N_DBL(INFINITY),  INT64_MAX && errno == ERANGE);
+	CHECK_GET_INT64(N_DBL(-INFINITY), INT64_MIN && errno == ERANGE);
 	CHECK_GET_INT64(N_DBL(NAN),       INT64_MIN && errno == EINVAL);
 	printf("INT64 GET PASSED\n");
 
 	CHECK_GET_UINT64(N_U64(UINT64_MAX), UINT64_MAX && errno == 0);
 	CHECK_GET_UINT64(N_U64(-1),         UINT64_MAX && errno == 0);
 	CHECK_GET_UINT64(N_STR(U64_OUT_S),  UINT64_MAX && errno == ERANGE);
+	CHECK_GET_UINT64(N_DBL(INFINITY),   UINT64_MAX && errno == ERANGE);
+	CHECK_GET_UINT64(N_DBL(-INFINITY),  0          && errno == ERANGE);
 	CHECK_GET_UINT64(N_DBL(NAN),        0          && errno == EINVAL);
 	printf("UINT64 GET PASSED\n");