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shell: implement optional "BASE#nnnn" numeric literals

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function                                             old     new   delta
evaluate_string                                      729     851    +122

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2019-05-19 17:23:31 +02:00
parent 30a4c32a4d
commit 9edd268bad
3 changed files with 51 additions and 6 deletions
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5
shell/Config.src
View File

@ -99,6 +99,11 @@ config FEATURE_SH_MATH_64
slightly larger, but will allow computation with very large numbers.
This is not in POSIX, so do not rely on this in portable code.
config FEATURE_SH_MATH_BASE
bool "Support BASE#nnnn literals"
default y
depends on FEATURE_SH_MATH
config FEATURE_SH_EXTRA_QUIET
bool "Hide message on interactive shell startup"
default y

36
shell/math.c
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@ -513,6 +513,42 @@ static const char op_tokens[] ALIGN1 = {
};
#define ptr_to_rparen (&op_tokens[sizeof(op_tokens)-7])
#if ENABLE_FEATURE_SH_MATH_BASE
static arith_t strto_arith_t(const char *nptr, char **endptr)
{
unsigned base;
arith_t n;
# if ENABLE_FEATURE_SH_MATH_64
n = strtoull(nptr, endptr, 0);
# else
n = strtoul(nptr, endptr, 0);
# endif
if (**endptr != '#'
|| (*nptr < '1' || *nptr > '9')
|| (n < 2 || n > 64)
) {
return n;
}
/* It's "N#nnnn" or "NN#nnnn" syntax, NN can't start with 0,
* NN is in 2..64 range.
*/
base = (unsigned)n;
n = 0;
nptr = *endptr + 1;
/* bash allows "N#" (empty "nnnn" part) */
while (isdigit(*nptr)) {
/* bash does not check for overflows */
n = n * base + (*nptr++ - '0');
}
*endptr = (char*)nptr;
return n;
}
#define strto_arith_t(nptr, endptr, base_is_always_0) \
strto_arith_t(nptr, endptr)
#endif
static arith_t FAST_FUNC
evaluate_string(arith_state_t *math_state, const char *expr)
{

16
shell/math.h
View File

@ -65,15 +65,19 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
#if ENABLE_FEATURE_SH_MATH_64
typedef long long arith_t;
#define ARITH_FMT "%lld"
#define strto_arith_t strtoull
# define ARITH_FMT "%lld"
#else
typedef long arith_t;
#define ARITH_FMT "%ld"
#define strto_arith_t strtoul
# define ARITH_FMT "%ld"
#endif
#if !ENABLE_FEATURE_SH_MATH_BASE
# if ENABLE_FEATURE_SH_MATH_64
# define strto_arith_t strtoull
# else
# define strto_arith_t strtoul
# endif
#endif
//TODO: bash supports "BASE#nnnnn" numeric literals, e.g. 2#1111 = 15.
//Make strto_arith_t() support that?
typedef const char* FAST_FUNC (*arith_var_lookup_t)(const char *name);
typedef void FAST_FUNC (*arith_var_set_t)(const char *name, const char *val);