Skip to content

lib: avoided increments/decrements with side effects #72806

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jun 21, 2024
Merged

lib: avoided increments/decrements with side effects #72806

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions lib/crc/crc16_sw.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -54,7 +54,8 @@ uint16_t crc16_ccitt(uint16_t seed, const uint8_t *src, size_t len)
for (; len > 0; len--) {
uint8_t e, f;

e = seed ^ *src++;
e = seed ^ *src;
++src;
f = e ^ (e << 4);
seed = (seed >> 8) ^ ((uint16_t)f << 8) ^ ((uint16_t)f << 3) ^ ((uint16_t)f >> 4);
}
Expand All @@ -66,7 +67,8 @@ uint16_t crc16_itu_t(uint16_t seed, const uint8_t *src, size_t len)
{
for (; len > 0; len--) {
seed = (seed >> 8U) | (seed << 8U);
seed ^= *src++;
seed ^= *src;
++src;
seed ^= (seed & 0xffU) >> 4U;
seed ^= seed << 12U;
seed ^= (seed & 0xffU) << 5U;
Expand Down
129 changes: 82 additions & 47 deletions lib/os/cbprintf_complete.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -515,7 +515,8 @@ static inline const char *extract_specifier(struct conversion *conv,
{
bool unsupported = false;

conv->specifier = *sp++;
conv->specifier = *sp;
++sp;

switch (conv->specifier) {
case SINT_CONV_CASES:
Expand Down Expand Up @@ -652,7 +653,8 @@ static inline const char *extract_conversion(struct conversion *conv,
*/
++sp;
if (*sp == '%') {
conv->specifier = *sp++;
conv->specifier = *sp;
++sp;
return sp;
}

Expand Down Expand Up @@ -797,7 +799,8 @@ static char *encode_uint(uint_value_type value,
do {
unsigned int lsv = (unsigned int)(value % radix);

*--bp = (lsv <= 9) ? ('0' + lsv)
--bp;
*bp = (lsv <= 9) ? ('0' + lsv)
: upcase ? ('A' + lsv - 10) : ('a' + lsv - 10);
value /= radix;
} while ((value != 0) && (bps < bp));
Expand Down Expand Up @@ -906,23 +909,27 @@ static char *encode_float(double value,
if (expo == BIT_MASK(EXPONENT_BITS)) {
if (fract == 0) {
if (isupper((unsigned char)c) != 0) {
*buf++ = 'I';
*buf++ = 'N';
*buf++ = 'F';
buf[0] = 'I';
buf[1] = 'N';
buf[2] = 'F';
buf += 3;
} else {
*buf++ = 'i';
*buf++ = 'n';
*buf++ = 'f';
buf[0] = 'i';
buf[1] = 'n';
buf[2] = 'f';
buf += 3;
}
} else {
if (isupper((unsigned char)c) != 0) {
*buf++ = 'N';
*buf++ = 'A';
*buf++ = 'N';
buf[0] = 'N';
buf[1] = 'A';
buf[2] = 'N';
buf += 3;
} else {
*buf++ = 'n';
*buf++ = 'a';
*buf++ = 'n';
buf[0] = 'n';
buf[1] = 'a';
buf[2] = 'n';
buf += 3;
}
}

Expand All @@ -942,19 +949,22 @@ static char *encode_float(double value,
if (IS_ENABLED(CONFIG_CBPRINTF_FP_A_SUPPORT)
&& (IS_ENABLED(CONFIG_CBPRINTF_FP_ALWAYS_A)
|| conv->specifier_a)) {
*buf++ = '0';
*buf++ = 'x';
buf[0] = '0';
buf[1] = 'x';
buf += 2;

/* Remove the offset from the exponent, and store the
* non-fractional value. Subnormals require increasing the
* exponent as first bit isn't the implicit bit.
*/
expo -= 1023;
if (is_subnormal) {
*buf++ = '0';
*buf = '0';
++buf;
++expo;
} else {
*buf++ = '1';
*buf = '1';
++buf;
}

/* If we didn't get precision from a %a specification then we
Expand Down Expand Up @@ -990,7 +1000,8 @@ static char *encode_float(double value,
bool require_dp = ((fract != 0) || conv->flag_hash);

if (require_dp || (precision != 0)) {
*buf++ = '.';
*buf = '.';
++buf;
}

/* Get the fractional value as a hexadecimal string, using x
Expand All @@ -1010,12 +1021,15 @@ static char *encode_float(double value,
* point.
*/
while ((spe - sp) < FRACTION_HEX) {
*--sp = '0';
--sp;
*sp = '0';
}

/* Append the leading significant "digits". */
while ((sp < spe) && (precision > 0)) {
*buf++ = *sp++;
*buf = *sp;
++buf;
++sp;
--precision;
}

Expand All @@ -1028,19 +1042,24 @@ static char *encode_float(double value,
}
}

*buf++ = 'p';
*buf = 'p';
++buf;
if (expo >= 0) {
*buf++ = '+';
*buf = '+';
++buf;
} else {
*buf++ = '-';
*buf = '-';
++buf;
expo = -expo;
}

aconv.specifier = 'i';
sp = encode_uint(expo, &aconv, buf, spe);

while (sp < spe) {
*buf++ = *sp++;
*buf = *sp;
++buf;
++sp;
}

*bpe = buf;
Expand Down Expand Up @@ -1174,22 +1193,25 @@ static char *encode_float(double value,
if (decexp > 0) {
/* Emit the digits above the decimal point. */
while ((decexp > 0) && (digit_count > 0)) {
*buf++ = _get_digit(&fract, &digit_count);
*buf = _get_digit(&fract, &digit_count);
++buf;
decexp--;
}

conv->pad0_value = decexp;

decexp = 0;
} else {
*buf++ = '0';
*buf = '0';
++buf;
}

/* Emit the decimal point only if required by the alternative
* format, or if more digits are to follow.
*/
if (conv->flag_hash || (precision > 0)) {
*buf++ = '.';
*buf = '.';
++buf;
}

if ((decexp < 0) && (precision > 0)) {
Expand All @@ -1214,45 +1236,52 @@ static char *encode_float(double value,
* format, or if more digits are to follow.
*/
if (conv->flag_hash || (precision > 0)) {
*buf++ = '.';
*buf = '.';
++buf;
}
}

while ((precision > 0) && (digit_count > 0)) {
*buf++ = _get_digit(&fract, &digit_count);
*buf = _get_digit(&fract, &digit_count);
++buf;
precision--;
}

conv->pad0_pre_exp = precision;

if (prune_zero) {
conv->pad0_pre_exp = 0;
while (*--buf == '0') {
;
}
do {
--buf;
} while (*buf == '0');
if (*buf != '.') {
buf++;
++buf;
}
}

/* Emit the explicit exponent, if format requires it. */
if ((c == 'e') || (c == 'E')) {
*buf++ = c;
*buf = c;
++buf;
if (decexp < 0) {
decexp = -decexp;
*buf++ = '-';
*buf = '-';
++buf;
} else {
*buf++ = '+';
*buf = '+';
++buf;
}

/* At most 3 digits to the decimal. Spit them out. */
if (decexp >= 100) {
*buf++ = (decexp / 100) + '0';
*buf = (decexp / 100) + '0';
++buf;
decexp %= 100;
}

*buf++ = (decexp / 10) + '0';
*buf++ = (decexp % 10) + '0';
buf[0] = (decexp / 10) + '0';
buf[1] = (decexp % 10) + '0';
buf += 2;
}

/* Cache whether there's padding required */
Expand Down Expand Up @@ -1324,7 +1353,8 @@ static int outs(cbprintf_cb out,
size_t count = 0;

while ((sp < ep) || ((ep == NULL) && *sp)) {
int rc = out((int)*sp++, ctx);
int rc = out((int)*sp, ctx);
++sp;

if (rc < 0) {
return rc;
Expand Down Expand Up @@ -1374,7 +1404,8 @@ int z_cbvprintf_impl(cbprintf_cb out, void *ctx, const char *fp,

while (*fp != 0) {
if (*fp != '%') {
OUTC(*fp++);
OUTC(*fp);
++fp;
continue;
}

Expand Down Expand Up @@ -1782,11 +1813,13 @@ int z_cbvprintf_impl(cbprintf_cb out, void *ctx, const char *fp,
if (conv->specifier_a) {
/* Only padding is pre_exp */
while (*cp != 'p') {
OUTC(*cp++);
OUTC(*cp);
++cp;
}
} else {
while (isdigit((unsigned char)*cp) != 0) {
OUTC(*cp++);
OUTC(*cp);
++cp;
}

pad_len = conv->pad0_value;
Expand All @@ -1797,7 +1830,8 @@ int z_cbvprintf_impl(cbprintf_cb out, void *ctx, const char *fp,
}

if (*cp == '.') {
OUTC(*cp++);
OUTC(*cp);
++cp;
/* Remaining padding is
* post-dp.
*/
Expand All @@ -1806,7 +1840,8 @@ int z_cbvprintf_impl(cbprintf_cb out, void *ctx, const char *fp,
}
}
while (isdigit((unsigned char)*cp) != 0) {
OUTC(*cp++);
OUTC(*cp);
++cp;
}
}

Expand Down
12 changes: 8 additions & 4 deletions lib/os/cbprintf_packaged.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -335,7 +335,8 @@ int cbvprintf_package(void *packaged, size_t len, uint32_t flags,
* reason for the post-decrement on fmt as it will be incremented
* prior to the next (actually first) round of that loop.
*/
s = fmt--;
s = fmt;
--fmt;
align = VA_STACK_ALIGN(char *);
size = sizeof(char *);
goto process_string;
Expand Down Expand Up @@ -766,7 +767,8 @@ int cbvprintf_package(void *packaged, size_t len, uint32_t flags,
return -ENOSPC;
}
/* store the pointer position prefix */
*buf++ = pos;
*buf = pos;
++buf;
}
}

Expand Down Expand Up @@ -794,7 +796,8 @@ int cbvprintf_package(void *packaged, size_t len, uint32_t flags,
return -ENOSPC;
}
/* store the pointer position prefix */
*buf++ = str_ptr_pos[i];
*buf = str_ptr_pos[i];
++buf;
/* copy the string with its terminating '\0' */
memcpy(buf, (uint8_t *)s, size);
buf += size;
Expand Down Expand Up @@ -851,7 +854,8 @@ int cbpprintf_external(cbprintf_cb out,
*/
for (i = 0; i < s_nbr; i++) {
/* Locate pointer location for this string */
s_idx = *(uint8_t *)s++;
s_idx = *(uint8_t *)s;
++s;
ps = (char **)(buf + s_idx * sizeof(int));
/* update the pointer with current string location */
*ps = s;
Expand Down
10 changes: 6 additions & 4 deletions lib/os/printk.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -97,7 +97,8 @@ static int buf_char_out(int c, void *ctx_p)
{
struct buf_out_context *ctx = ctx_p;

ctx->buf[ctx->buf_count++] = c;
ctx->buf[ctx->buf_count] = c;
++ctx->buf_count;
if (ctx->buf_count == CONFIG_PRINTK_BUFFER_SIZE) {
buf_flush(ctx);
}
Expand Down Expand Up @@ -226,15 +227,16 @@ struct str_context {
static int str_out(int c, struct str_context *ctx)
{
if ((ctx->str == NULL) || (ctx->count >= ctx->max)) {
ctx->count++;
++ctx->count;
return c;
}

if (ctx->count == (ctx->max - 1)) {
ctx->str[ctx->count++] = '\0';
ctx->str[ctx->count] = '\0';
} else {
ctx->str[ctx->count++] = c;
ctx->str[ctx->count] = c;
}
++ctx->count;

return c;
}
Expand Down
Loading