diff --git a/sys/fmt/fmt.c b/sys/fmt/fmt.c
index 4000943f7ddea6c1e32e49e734f43d3831529104..fd1a88d41d0d5cb2f0ef01e45061c2afc3a5859e 100644
--- a/sys/fmt/fmt.c
+++ b/sys/fmt/fmt.c
@@ -46,6 +46,8 @@ static const uint32_t _tenmap[] = {
10000000LU,
};
+#define TENMAP_SIZE (sizeof(_tenmap) / sizeof(_tenmap[0]))
+
static inline int _is_digit(char c)
{
return (c >= '0' && c <= '9');
@@ -200,58 +202,17 @@ size_t fmt_s16_dec(char *out, int16_t val)
size_t fmt_s16_dfp(char *out, int16_t val, unsigned fp_digits)
{
- int16_t absolute, divider;
- size_t pos = 0;
- size_t div_len, len;
- unsigned e;
- char tmp[4];
-
- if (fp_digits > 4) {
- return 0;
- }
- if (fp_digits == 0) {
- return fmt_s16_dec(out, val);
- }
- if (val < 0) {
- if (out) {
- out[pos++] = '-';
- }
- val = -val;
- }
-
- e = _tenmap[fp_digits];
- absolute = (val / (int)e);
- divider = val - (absolute * e);
-
- pos += fmt_s16_dec(&out[pos], absolute);
-
- if (!out) {
- return pos + 1 + fp_digits; /* abs len + decimal point + divider */
- }
-
- out[pos++] = '.';
- len = pos + fp_digits;
- div_len = fmt_s16_dec(tmp, divider);
-
- while (pos < (len - div_len)) {
- out[pos++] = '0';
- }
- for (size_t i = 0; i < div_len; i++) {
- out[pos++] = tmp[i];
- }
-
- return pos;
+ return fmt_s32_dfp(out, val, fp_digits);
}
size_t fmt_s32_dfp(char *out, int32_t val, unsigned fp_digits)
{
+ assert(fp_digits < TENMAP_SIZE);
+
int32_t absolute, divider;
unsigned div_len, len, pos = 0;
char tmp[9];
- if (fp_digits > 9) {
- return 0;
- }
if (fp_digits == 0) {
return fmt_s32_dec(out, val);
}
@@ -292,7 +253,7 @@ size_t fmt_s32_dfp(char *out, int32_t val, unsigned fp_digits)
*/
size_t fmt_float(char *out, float f, unsigned precision)
{
- assert (precision <= 7);
+ assert(precision < TENMAP_SIZE);
unsigned negative = (f < 0);
uint32_t integer;
diff --git a/sys/include/fmt.h b/sys/include/fmt.h
index afdb5e2d9525f9b8a42ad20a10f156f2d044675c..e1d0dfb38c5c81920937373b5cb36694afa19572 100644
--- a/sys/include/fmt.h
+++ b/sys/include/fmt.h
@@ -194,12 +194,13 @@ size_t fmt_s16_dec(char *out, int16_t val);
* If @p out is NULL, will only return the number of bytes that would have
* been written.
*
+ * @pre fp_digits < 8 (TENMAP_SIZE)
+ *
* @param[out] out Pointer to the output buffer, or NULL
- * @param[in] val Fixed point value, MUST be <= 4
+ * @param[in] val Fixed point value
* @param[in] fp_digits Number of digits after the decimal point
*
* @return Length of the resulting string
- * @return 0 if @p fp_digits is > 4
*/
size_t fmt_s16_dfp(char *out, int16_t val, unsigned fp_digits);
@@ -222,12 +223,13 @@ size_t fmt_s16_dfp(char *out, int16_t val, unsigned fp_digits);
* If @p out is NULL, will only return the number of bytes that would have
* been written.
*
+ * @pre fp_digits < 8 (TENMAP_SIZE)
+ *
* @param[out] out Pointer to the output buffer, or NULL
* @param[in] val Fixed point value
- * @param[in] fp_digits Number of digits after the decimal point, MUST be <= 9
+ * @param[in] fp_digits Number of digits after the decimal point
*
* @return Length of the resulting string
- * @return 0 if @p fp_digits is > 9
*/
size_t fmt_s32_dfp(char *out, int32_t val, unsigned fp_digits);
@@ -236,14 +238,18 @@ size_t fmt_s32_dfp(char *out, int32_t val, unsigned fp_digits);
*
* Converts float value @p f to string
*
- * @pre -2^32 < f < 2^32
+ * If @p out is NULL, will only return the number of bytes that would have
+ * been written.
*
- * @note This function is using floating point math. It pulls in about 2.4k
- * bytes of code on ARM Cortex-M platforms.
+ * @attention This function is using floating point math.
+ * It pulls in about 2.4k bytes of code on ARM Cortex-M platforms.
+ *
+ * @pre -2^32 < f < 2^32
+ * @pre precision < 8 (TENMAP_SIZE)
*
* @param[out] out string to write to (or NULL)
* @param[in] f float value to convert
- * @param[in] precision number of digits after decimal point (<=7)
+ * @param[in] precision number of digits after decimal point
*
* @returns nr of bytes the function did or would write to out
*/
@@ -340,18 +346,19 @@ void print_u64_dec(uint64_t val);
/**
* @brief Print float value
*
+ * @note See fmt_float for code size warning!
+ *
* @pre -2^32 < f < 2^32
+ * @pre precision < TENMAP_SIZE (== 8)
*
* @param[in] f float value to print
- * @param[in] precision number of digits after decimal point (<=7)
+ * @param[in] precision number of digits after decimal point
*/
void print_float(float f, unsigned precision);
/**
* @brief Print null-terminated string to stdout
*
- * @note See fmt_float for code size warning!
- *
* @param[in] str Pointer to string to print
*/
void print_str(const char* str);
diff --git a/tests/unittests/tests-fmt/tests-fmt.c b/tests/unittests/tests-fmt/tests-fmt.c
index 251f05cdf7564cf28516f1c736ea94f35953193d..25a94297fa8cfe6257a84ab84806cecc8cb92aff 100644
--- a/tests/unittests/tests-fmt/tests-fmt.c
+++ b/tests/unittests/tests-fmt/tests-fmt.c
@@ -36,7 +36,7 @@ static void test_fmt_byte_hex(void)
static void test_fmt_bytes_hex_reverse(void)
{
- char out[10];
+ char out[9] = "--------";
uint8_t val[4] = { 9, 8, 7, 6 };
uint8_t bytes = 0;
@@ -105,7 +105,7 @@ static void test_fmt_u16_dec(void)
static void test_fmt_s32_dec(void)
{
- char out[8] = "--------";
+ char out[6] = "-----";
int32_t val = 9876;
uint8_t chars = 0;
@@ -123,7 +123,7 @@ static void test_fmt_s32_dec(void)
static void test_fmt_u64_dec_a(void)
{
- char out[21] = "------------------";
+ char out[21] = "--------------------";
uint64_t val = 0;
uint8_t chars = 0;
@@ -159,7 +159,7 @@ static void test_fmt_u64_dec_c(void)
static void test_fmt_s16_dec(void)
{
- char out[7] = "-------";
+ char out[7] = "------";
int16_t val;
size_t len;
@@ -184,7 +184,7 @@ static void test_fmt_s16_dec(void)
static void test_fmt_s16_dfp(void)
{
- char out[8] = "--------";
+ char out[9] = "--------";
int16_t val;
unsigned fpp;
size_t len;
@@ -239,11 +239,11 @@ static void test_fmt_s16_dfp(void)
TEST_ASSERT_EQUAL_STRING("-12345", (char *)out);
val = 31987;
- fpp = 5;
+ fpp = 6;
len = fmt_s16_dfp(out, val, fpp);
out[len] = '\0';
- TEST_ASSERT_EQUAL_INT(0, len);
- TEST_ASSERT_EQUAL_STRING("", (char *)out);
+ TEST_ASSERT_EQUAL_INT(8, len);
+ TEST_ASSERT_EQUAL_STRING("0.031987", (char *)out);
}
static void test_fmt_s32_dfp(void)
@@ -254,11 +254,11 @@ static void test_fmt_s32_dfp(void)
size_t len;
val = 0;
- fpp = 8;
+ fpp = 7;
len = fmt_s32_dfp(out, val, fpp);
out[len] = '\0';
- TEST_ASSERT_EQUAL_INT(10, len);
- TEST_ASSERT_EQUAL_STRING("0.00000000", (char *)out);
+ TEST_ASSERT_EQUAL_INT(9, len);
+ TEST_ASSERT_EQUAL_STRING("0.0000000", (char *)out);
val = 123456789;
fpp = 7;
@@ -282,11 +282,11 @@ static void test_fmt_s32_dfp(void)
TEST_ASSERT_EQUAL_STRING("-3.14159", (char *)out);
val = -23;
- fpp = 9;
+ fpp = 7;
len = fmt_s32_dfp(out, val, fpp);
out[len] = '\0';
- TEST_ASSERT_EQUAL_INT(12, len);
- TEST_ASSERT_EQUAL_STRING("-0.000000023", (char *)out);
+ TEST_ASSERT_EQUAL_INT(10, len);
+ TEST_ASSERT_EQUAL_STRING("-0.0000023", (char *)out);
val = 50;
fpp = 6;
@@ -301,13 +301,6 @@ static void test_fmt_s32_dfp(void)
out[len] = '\0';
TEST_ASSERT_EQUAL_INT(10, len);
TEST_ASSERT_EQUAL_STRING("-123456789", (char *)out);
-
- val = 31987;
- fpp = 10;
- len = fmt_s32_dfp(out, val, fpp);
- out[len] = '\0';
- TEST_ASSERT_EQUAL_INT(0, len);
- TEST_ASSERT_EQUAL_STRING("", (char *)out);
}
static void test_fmt_strlen(void)