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shell/math.c: rename arith_eval_hooks to arith_state, put error code into it

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function                                             old     new   delta
expand_and_evaluate_arith                             79      89     +10
arith                                                675     674      -1
arith_lookup_val                                     151     142      -9
ash_arith                                            135     122     -13
arith_apply                                         1304    1269     -35
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/4 up/down: 10/-58)            Total: -48 bytes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
This commit is contained in:
Denys Vlasenko 2010-09-13 12:49:03 +02:00
parent bd14770b0c
commit 06d44d7dfb
4 changed files with 78 additions and 81 deletions
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19
shell/ash.c
View File

@ -5442,22 +5442,21 @@ redirectsafe(union node *redir, int flags)
static arith_t static arith_t
ash_arith(const char *s) ash_arith(const char *s)
{ {
arith_eval_hooks_t math_hooks; arith_state_t math_state;
arith_t result; arith_t result;
int errcode = 0;
math_hooks.lookupvar = lookupvar; math_state.lookupvar = lookupvar;
math_hooks.setvar = setvar2; math_state.setvar = setvar2;
//math_hooks.endofname = endofname; //math_state.endofname = endofname;
INT_OFF; INT_OFF;
result = arith(s, &errcode, &math_hooks); result = arith(&math_state, s);
if (errcode < 0) { if (math_state.errcode < 0) {
if (errcode == -3) if (math_state.errcode == -3)
ash_msg_and_raise_error("exponent less than 0"); ash_msg_and_raise_error("exponent less than 0");
if (errcode == -2) if (math_state.errcode == -2)
ash_msg_and_raise_error("divide by zero"); ash_msg_and_raise_error("divide by zero");
if (errcode == -5) if (math_state.errcode == -5)
ash_msg_and_raise_error("expression recursion loop detected"); ash_msg_and_raise_error("expression recursion loop detected");
raise_error_syntax(s); raise_error_syntax(s);
} }

11
shell/hush.c
View File

@ -4463,15 +4463,16 @@ static char *encode_then_expand_string(const char *str, int process_bkslash, int
#if ENABLE_SH_MATH_SUPPORT #if ENABLE_SH_MATH_SUPPORT
static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p) static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
{ {
arith_eval_hooks_t hooks; arith_state_t math_state;
arith_t res; arith_t res;
char *exp_str; char *exp_str;
hooks.lookupvar = get_local_var_value; math_state.lookupvar = get_local_var_value;
hooks.setvar = set_local_var_from_halves; math_state.setvar = set_local_var_from_halves;
//hooks.endofname = endofname; //math_state.endofname = endofname;
exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1); exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
res = arith(exp_str ? exp_str : arg, errcode_p, &hooks); res = arith(&math_state, exp_str ? exp_str : arg);
*errcode_p = math_state.errcode;
free(exp_str); free(exp_str);
return res; return res;
} }

38
shell/math.c
View File

@ -119,10 +119,9 @@
#include "libbb.h" #include "libbb.h"
#include "math.h" #include "math.h"
#define a_e_h_t arith_eval_hooks_t #define lookupvar (math_state->lookupvar)
#define lookupvar (math_hooks->lookupvar) #define setvar (math_state->setvar )
#define setvar (math_hooks->setvar ) //#define endofname (math_state->endofname)
//#define endofname (math_hooks->endofname)
typedef unsigned char operator; typedef unsigned char operator;
@ -249,13 +248,12 @@ typedef struct chk_var_recursive_looped_t {
static chk_var_recursive_looped_t *prev_chk_var_recursive; static chk_var_recursive_looped_t *prev_chk_var_recursive;
static int static int
arith_lookup_val(v_n_t *t, a_e_h_t *math_hooks) arith_lookup_val(arith_state_t *math_state, v_n_t *t)
{ {
if (t->var) { if (t->var) {
const char *p = lookupvar(t->var); const char *p = lookupvar(t->var);
if (p) { if (p) {
int errcode;
chk_var_recursive_looped_t *cur; chk_var_recursive_looped_t *cur;
chk_var_recursive_looped_t cur_save; chk_var_recursive_looped_t cur_save;
@ -273,10 +271,10 @@ arith_lookup_val(v_n_t *t, a_e_h_t *math_hooks)
cur_save.next = cur; cur_save.next = cur;
prev_chk_var_recursive = &cur_save; prev_chk_var_recursive = &cur_save;
t->val = arith(p, &errcode, math_hooks); t->val = arith(math_state, p);
/* restore previous ptr after recursion */ /* restore previous ptr after recursion */
prev_chk_var_recursive = cur; prev_chk_var_recursive = cur;
return errcode; return math_state->errcode;
} }
/* allow undefined var as 0 */ /* allow undefined var as 0 */
t->val = 0; t->val = 0;
@ -288,13 +286,13 @@ arith_lookup_val(v_n_t *t, a_e_h_t *math_hooks)
* stack. For an unary operator it will only change the top element, but a * stack. For an unary operator it will only change the top element, but a
* binary operator will pop two arguments and push the result */ * binary operator will pop two arguments and push the result */
static NOINLINE int static NOINLINE int
arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr, a_e_h_t *math_hooks) arith_apply(arith_state_t *math_state, operator op, v_n_t *numstack, v_n_t **numstackptr)
{ {
#define NUMPTR (*numstackptr) #define NUMPTR (*numstackptr)
v_n_t *numptr_m1; v_n_t *numptr_m1;
arith_t numptr_val, rez; arith_t numptr_val, rez;
int ret_arith_lookup_val; int err;
/* There is no operator that can work without arguments */ /* There is no operator that can work without arguments */
if (NUMPTR == numstack) if (NUMPTR == numstack)
@ -302,9 +300,9 @@ arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr, a_e_h_t *math_hoo
numptr_m1 = NUMPTR - 1; numptr_m1 = NUMPTR - 1;
/* Check operand is var with noninteger value */ /* Check operand is var with noninteger value */
ret_arith_lookup_val = arith_lookup_val(numptr_m1, math_hooks); err = arith_lookup_val(math_state, numptr_m1);
if (ret_arith_lookup_val) if (err)
return ret_arith_lookup_val; return err;
rez = numptr_m1->val; rez = numptr_m1->val;
if (op == TOK_UMINUS) if (op == TOK_UMINUS)
@ -339,9 +337,9 @@ arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr, a_e_h_t *math_hoo
numptr_m1 = NUMPTR - 1; numptr_m1 = NUMPTR - 1;
if (op != TOK_ASSIGN) { if (op != TOK_ASSIGN) {
/* check operand is var with noninteger value for not '=' */ /* check operand is var with noninteger value for not '=' */
ret_arith_lookup_val = arith_lookup_val(numptr_m1, math_hooks); err = arith_lookup_val(math_state, numptr_m1);
if (ret_arith_lookup_val) if (err)
return ret_arith_lookup_val; return err;
} }
if (op == TOK_CONDITIONAL) { if (op == TOK_CONDITIONAL) {
numptr_m1->contidional_second_val = rez; numptr_m1->contidional_second_val = rez;
@ -490,7 +488,7 @@ endofname(const char *name)
} }
arith_t arith_t
arith(const char *expr, int *perrcode, a_e_h_t *math_hooks) arith(arith_state_t *math_state, const char *expr)
{ {
operator lasttok; operator lasttok;
int errcode; int errcode;
@ -543,7 +541,7 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks)
} }
if (numstack->var) { if (numstack->var) {
/* expression is $((var)) only, lookup now */ /* expression is $((var)) only, lookup now */
errcode = arith_lookup_val(numstack, math_hooks); errcode = arith_lookup_val(math_state, numstack);
} }
goto ret; goto ret;
} }
@ -658,7 +656,7 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks)
break; break;
} }
} }
errcode = arith_apply(prev_op, numstack, &numstackptr, math_hooks); errcode = arith_apply(math_state, prev_op, numstack, &numstackptr);
if (errcode) if (errcode)
goto ret; goto ret;
} }
@ -675,7 +673,7 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks)
err: err:
numstack->val = errcode = -1; numstack->val = errcode = -1;
ret: ret:
*perrcode = errcode; math_state->errcode = errcode;
return numstack->val; return numstack->val;
} }

91
shell/math.h
View File

@ -9,61 +9,59 @@
/* The math library has just one function: /* The math library has just one function:
* *
* arith_t arith(const char *expr, int *perrcode, arith_eval_hooks_t *hooks); * arith_t arith(arith_state_t *states, const char *expr);
* *
* The first argument is the math string to parse. All normal expansions must * The expr argument is the math string to parse. All normal expansions must
* be done already. i.e. no dollar symbols should be present. * be done already. i.e. no dollar symbols should be present.
* *
* The second argument is a semi-detailed error description in case something * The state argument is a pointer to a struct of hooks for your shell (see below),
* goes wrong in the parsing steps. Currently, those values are (for * and a semi-detailed error code. Currently, those values are (for
* compatibility, you should assume all negative values are errors): * compatibility, you should assume all negative values are errors):
* 0 - no errors (yay!) * 0 - no errors (yay!)
* -1 - unspecified problem * -1 - unspecified problem
* -2 - divide by zero * -2 - divide by zero
* -3 - exponent less than 0 * -3 - exponent less than 0
* -5 - expression recursion loop detected * -5 - expression recursion loop detected
* *
* The third argument is a struct pointer of hooks for your shell (see below). * The function returns the answer to the expression. So if you called it
* * with the expression:
* The function returns the answer to the expression. So if you called it * "1 + 2 + 3"
* with the expression: * you would obviously get back 6.
* "1 + 2 + 3"
* You would obviously get back 6.
*/ */
/* To add support to a shell, you need to implement three functions: /* To add support to a shell, you need to implement three functions:
* *
* lookupvar() - look up and return the value of a variable * lookupvar() - look up and return the value of a variable
* *
* If the shell does: * If the shell does:
* foo=123 * foo=123
* Then the code: * Then the code:
* const char *val = lookupvar("foo"); * const char *val = lookupvar("foo");
* Will result in val pointing to "123" * will result in val pointing to "123"
* *
* setvar() - set a variable to some value * setvar() - set a variable to some value
* *
* If the arithmetic expansion does something like: * If the arithmetic expansion does something like:
* $(( i = 1)) * $(( i = 1))
* Then the math code will make a call like so: * then the math code will make a call like so:
* setvar("i", "1", 0); * setvar("i", "1", 0);
* The storage for the first two parameters are not allocated, so your * The storage for the first two parameters are not allocated, so your
* shell implementation will most likely need to strdup() them to save. * shell implementation will most likely need to strdup() them to save.
* *
* endofname() - return the end of a variable name from input * endofname() - return the end of a variable name from input
* *
* The arithmetic code does not know about variable naming conventions. * The arithmetic code does not know about variable naming conventions.
* So when it is given an experession, it knows something is not numeric, * So when it is given an experession, it knows something is not numeric,
* but it is up to the shell to dictate what is a valid identifiers. * but it is up to the shell to dictate what is a valid identifiers.
* So when it encounters something like: * So when it encounters something like:
* $(( some_var + 123 )) * $(( some_var + 123 ))
* It will make a call like so: * It will make a call like so:
* end = endofname("some_var + 123"); * end = endofname("some_var + 123");
* So the shell needs to scan the input string and return a pointer to the * So the shell needs to scan the input string and return a pointer to the
* first non-identifier string. In this case, it should return the input * first non-identifier string. In this case, it should return the input
* pointer with an offset pointing to the first space. The typical * pointer with an offset pointing to the first space. The typical
* implementation will return the offset of first char that does not match * implementation will return the offset of first char that does not match
* the regex (in C locale): ^[a-zA-Z_][a-zA-Z_0-9]* * the regex (in C locale): ^[a-zA-Z_][a-zA-Z_0-9]*
*/ */
/* To make your life easier when dealing with optional 64bit math support, /* To make your life easier when dealing with optional 64bit math support,
@ -96,13 +94,14 @@ 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); typedef void FAST_FUNC (*arith_var_set_t)(const char *name, const char *val);
//typedef const char* FAST_FUNC (*arith_var_endofname_t)(const char *name); //typedef const char* FAST_FUNC (*arith_var_endofname_t)(const char *name);
typedef struct arith_eval_hooks { typedef struct arith_state_t {
arith_var_lookup_t lookupvar; arith_var_lookup_t lookupvar;
arith_var_set_t setvar; arith_var_set_t setvar;
// arith_var_endofname_t endofname; // arith_var_endofname_t endofname;
} arith_eval_hooks_t; int errcode;
} arith_state_t;
arith_t arith(const char *expr, int *perrcode, arith_eval_hooks_t*); arith_t arith(arith_state_t *state, const char *expr);
POP_SAVED_FUNCTION_VISIBILITY POP_SAVED_FUNCTION_VISIBILITY