Changeset e3272101 in mainline

Timestamp:

2019-02-11T14:08:52Z (6 years ago)

Author:

Matthieu Riolo <matthieu.riolo@…>

Children:

d5a89a3

Parents:

aa57bf7

Message:

make ilog10_u64() return an errno_t

The function ilog10_u64() used to return 0
for the value 0. Which is not correct. Either
NaN or -Infinity are correct, but not 0, since
it would be ambiguous with log(1). To ensure this
case the function ilog10_u64() has been changed
to return a errno_t indicating a failure.

Location:

uspace/lib/c

Files:

• generic/cap.c (modified) (1 diff)
• generic/imath.c (modified) (2 diffs)
• include/imath.h (modified) (1 diff)
• test/imath.c (modified) (1 diff)

uspace/lib/c/generic/cap.c

@@ -160 +160 @@
 
         /* Round the number so that we have at most @c scap_max_sdig significant digits */
-        sdig = 1 + ilog10_u64(cap->m); /* number of significant digits */
+        rc = ilog10_u64(cap->m, &sdig); /* number of significant digits */
+        sdig += 1;
+        assert(rc == EOK);
         if (sdig > scap_max_sdig) {
                 /* Number of digits to remove */

uspace/lib/c/generic/imath.c

@@ -81 +81 @@
  *
  * @param v Value to compute logarithm from
+ * @param res Place to store result
+ * @return EOK on success
  * @return Logarithm value
  */
-unsigned ilog10_u64(uint64_t v)
+errno_t ilog10_u64(uint64_t v, unsigned *res)
 {
+        if (v == 0)
+                return ERANGE;
+
         unsigned b;
         unsigned e;
@@ -117 +122 @@
         }
 
-        return r;
+        *res = r;
+        return EOK;
 }
 

uspace/lib/c/include/imath.h

@@ -40 +40 @@
 
 extern errno_t ipow10_u64(unsigned, uint64_t *);
-extern unsigned ilog10_u64(uint64_t);
+extern errno_t ilog10_u64(uint64_t, unsigned *);
 
 #endif

uspace/lib/c/test/imath.c

@@ -78 +78 @@
 PCUT_TEST(ilog10_u64_zero)
 {
-        unsigned ret = ilog10_u64(0);
-        PCUT_ASSERT_INT_EQUALS(0, ret);
+        unsigned res;
+        errno_t ret = ilog10_u64(0, &res);
+        PCUT_ASSERT_ERRNO_VAL(ERANGE, ret);
 }
 
 PCUT_TEST(ilog10_u64_one)
 {
-        unsigned ret = ilog10_u64(1);
-        PCUT_ASSERT_INT_EQUALS(0, ret);
+        unsigned res;
+        errno_t ret = ilog10_u64(1, &res);
+        PCUT_ASSERT_ERRNO_VAL(EOK, ret);
+        PCUT_ASSERT_INT_EQUALS(0, res);
 }
 
 PCUT_TEST(ilog10_u64_max)
 {
-        unsigned ret = ilog10_u64(MAX_NUM);
-        PCUT_ASSERT_INT_EQUALS(MAX_EXP, ret);
+        unsigned res;
+        errno_t ret = ilog10_u64(MAX_NUM, &res);
+        PCUT_ASSERT_ERRNO_VAL(EOK, ret);
+        PCUT_ASSERT_INT_EQUALS(MAX_EXP, res);
 }