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parsenum: Signedness issues.

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char can be signedness, and using signedness types is dangerous - it can
lead to negative offsets when doing table lookups. We apparently should just
ban char usage.
This commit is contained in:
Paul Sokolovsky 2014-06-14 17:56:44 +03:00
parent 812025bd83
commit 0294661da5
2 changed files with 9 additions and 8 deletions
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13
py/parsenum.c
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@ -40,8 +40,9 @@
#include <math.h> #include <math.h>
#endif #endif
mp_obj_t mp_parse_num_integer(const char *restrict str, uint len, int base) { mp_obj_t mp_parse_num_integer(const char *restrict str_, uint len, int base) {
const char *restrict top = str + len; const byte *restrict str = (const byte *)str_;
const byte *restrict top = str + len;
bool neg = false; bool neg = false;
mp_obj_t ret_val; mp_obj_t ret_val;
@ -65,11 +66,11 @@ mp_obj_t mp_parse_num_integer(const char *restrict str, uint len, int base) {
} }
// parse optional base prefix // parse optional base prefix
str += mp_parse_num_base(str, top - str, &base); str += mp_parse_num_base((const char*)str, top - str, &base);
// string should be an integer number // string should be an integer number
machine_int_t int_val = 0; machine_int_t int_val = 0;
const char *restrict str_val_start = str; const byte *restrict str_val_start = str;
for (; str < top; str++) { for (; str < top; str++) {
// get next digit as a value // get next digit as a value
int dig = *str; int dig = *str;
@ -129,9 +130,9 @@ have_ret_val:
overflow: overflow:
// reparse using long int // reparse using long int
{ {
const char *s2 = str_val_start; const char *s2 = (const char*)str_val_start;
ret_val = mp_obj_new_int_from_str_len(&s2, top - str_val_start, neg, base); ret_val = mp_obj_new_int_from_str_len(&s2, top - str_val_start, neg, base);
str = s2; str = (const byte*)s2;
goto have_ret_val; goto have_ret_val;
} }

4
py/parsenumbase.c
View File

@ -31,7 +31,7 @@
// find real radix base, and strip preceding '0x', '0o' and '0b' // find real radix base, and strip preceding '0x', '0o' and '0b'
// puts base in *base, and returns number of bytes to skip the prefix // puts base in *base, and returns number of bytes to skip the prefix
int mp_parse_num_base(const char *str, uint len, int *base) { int mp_parse_num_base(const char *str, uint len, int *base) {
const char *p = str; const byte *p = (const byte*)str;
int c = *(p++); int c = *(p++);
if ((*base == 0 || *base == 16) && c == '0') { if ((*base == 0 || *base == 16) && c == '0') {
c = *(p++); c = *(p++);
@ -63,6 +63,6 @@ int mp_parse_num_base(const char *str, uint len, int *base) {
} }
p--; p--;
} }
return p - str; return p - (const byte*)str;
} }