type-props: New macro for estimating length of a decimal integer.

diff --git a/lib/type-props.h b/lib/type-props.h
index efaf4a5de48c649d7872663ce6809c04aa832111..9225041740b8fd503a5c60f265ce8441ab6ae85b 100644 (file)
--- a/lib/type-props.h
+++ b/lib/type-props.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008 Nicira Networks.
+ * Copyright (c) 2008, 2011 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,4 +29,11 @@
                             ? ~(~(TYPE)0 << TYPE_VALUE_BITS(TYPE)) \
                             : (TYPE)-1)
 
+/* Number of decimal digits required to format an integer of the given TYPE.
+ * Includes space for a sign, if TYPE is signed, but not for a null
+ * terminator.
+ *
+ * The value is an overestimate. */
+#define INT_STRLEN(TYPE) (TYPE_IS_SIGNED(TYPE) + TYPE_VALUE_BITS(TYPE) / 3 + 1)
+
 #endif /* type-props.h */

diff --git a/tests/test-type-props.c b/tests/test-type-props.c
index 0a1d3fd32c5479aeebab26fa76281d62581082e9..3c5ff6aeaba77b5133d9881e414bcbf02a3c2545 100644 (file)
--- a/tests/test-type-props.c
+++ b/tests/test-type-props.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2011 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,10 @@
 
 #include <config.h>
 #include "type-props.h"
+#include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #define MUST_SUCCEED(EXPRESSION)                    \
     if (!(EXPRESSION)) {                            \
@@ -30,11 +32,18 @@
     MUST_SUCCEED(TYPE_IS_INTEGER(type));                \
     MUST_SUCCEED(TYPE_IS_SIGNED(type) == is_signed);    \
     MUST_SUCCEED(TYPE_MAXIMUM(type) == maximum);        \
-    MUST_SUCCEED(TYPE_MINIMUM(type) == minimum);
+    MUST_SUCCEED(TYPE_MINIMUM(type) == minimum);        \
+    sprintf(max_s, "%"PRIuMAX, (uintmax_t) (maximum));  \
+    MUST_SUCCEED(strlen(max_s) <= INT_STRLEN(type));    \
+    sprintf(min_s, "%"PRIdMAX, (intmax_t) (minimum));   \
+    MUST_SUCCEED(strlen(min_s) <= INT_STRLEN(type));
 
 int
 main (void)
 {
+    char max_s[128];
+    char min_s[128];
+
     TEST_TYPE(char, CHAR_MIN, CHAR_MAX, (CHAR_MIN < 0));
 
     TEST_TYPE(signed char, SCHAR_MIN, SCHAR_MAX, 1);