0eac8ff16
Denys Vlasenko
2010-09-13
Subject
shell/math.c: stop using bss variable
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shell/math.c+34 -20
| @@ -232,6 +232,7 @@ is_right_associative(operator prec) | |
| || prec == PREC(TOK_CONDITIONAL)); | |
| } | |
| + | |
| typedef struct { | |
| arith_t val; | |
| arith_t contidional_second_val; | |
| @@ -240,43 +241,49 @@ typedef struct { | |
| else is variable name */ | |
| } v_n_t; | |
| - | typedef struct chk_var_recursive_looped_t { |
| + | typedef struct remembered_name { |
| + | struct remembered_name *next; |
| const char *var; | |
| - | struct chk_var_recursive_looped_t *next; |
| - | } chk_var_recursive_looped_t; |
| + | } remembered_name; |
| + | |
| - | static chk_var_recursive_looped_t *prev_chk_var_recursive; |
| + | static arith_t FAST_FUNC |
| + | evaluate_string(arith_state_t *math_state, const char *expr); |
| static int | |
| arith_lookup_val(arith_state_t *math_state, v_n_t *t) | |
| { | |
| if (t->var) { | |
| const char *p = lookupvar(t->var); | |
| - | |
| if (p) { | |
| - | chk_var_recursive_looped_t *cur; |
| - | chk_var_recursive_looped_t cur_save; |
| + | remembered_name *cur; |
| + | remembered_name cur_save; |
| - | /* recursively try p as expression */ |
| - | |
| - | for (cur = prev_chk_var_recursive; cur; cur = cur->next) { |
| + | /* did we already see this name? |
| + | * testcase: a=b; b=a; echo $((a)) |
| + | */ |
| + | for (cur = math_state->list_of_recursed_names; cur; cur = cur->next) { |
| if (strcmp(cur->var, t->var) == 0) { | |
| - | /* expression recursion loop detected */ |
| + | /* Yes. Expression recursion loop detected */ |
| return -5; | |
| } | |
| } | |
| - | /* save current var name */ |
| - | cur = prev_chk_var_recursive; |
| + | |
| + | /* push current var name */ |
| + | cur = math_state->list_of_recursed_names; |
| cur_save.var = t->var; | |
| cur_save.next = cur; | |
| - | prev_chk_var_recursive = &cur_save; |
| + | math_state->list_of_recursed_names = &cur_save; |
| + | |
| + | /* recursively evaluate p as expression */ |
| + | t->val = evaluate_string(math_state, p); |
| + | |
| + | /* pop current var name */ |
| + | math_state->list_of_recursed_names = cur; |
| - | t->val = arith(math_state, p); |
| - | /* restore previous ptr after recursion */ |
| - | prev_chk_var_recursive = cur; |
| return math_state->errcode; | |
| } | |
| - | /* allow undefined var as 0 */ |
| + | /* treat undefined var as 0 */ |
| t->val = 0; | |
| } | |
| return 0; | |
| @@ -487,8 +494,8 @@ endofname(const char *name) | |
| return name; | |
| } | |
| - | arith_t |
| - | arith(arith_state_t *math_state, const char *expr) |
| + | static arith_t FAST_FUNC |
| + | evaluate_string(arith_state_t *math_state, const char *expr) |
| { | |
| operator lasttok; | |
| int errcode; | |
| @@ -677,6 +684,13 @@ arith(arith_state_t *math_state, const char *expr) | |
| return numstack->val; | |
| } | |
| + | arith_t FAST_FUNC |
| + | arith(arith_state_t *math_state, const char *expr) |
| + | { |
| + | math_state->list_of_recursed_names = NULL; |
| + | return evaluate_string(math_state, expr); |
| + | } |
| + | |
| /* | |
| * Copyright (c) 1989, 1991, 1993, 1994 | |
| * The Regents of the University of California. All rights reserved. | |
shell/math.h+3 -2
| @@ -95,13 +95,14 @@ typedef void FAST_FUNC (*arith_var_set_t)(const char *name, const char *v | |
| //typedef const char* FAST_FUNC (*arith_var_endofname_t)(const char *name); | |
| typedef struct arith_state_t { | |
| + | int errcode; |
| arith_var_lookup_t lookupvar; | |
| arith_var_set_t setvar; | |
| // arith_var_endofname_t endofname; | |
| - | int errcode; |
| + | void *list_of_recursed_names; |
| } arith_state_t; | |
| - | arith_t arith(arith_state_t *state, const char *expr); |
| + | arith_t FAST_FUNC arith(arith_state_t *state, const char *expr); |
| POP_SAVED_FUNCTION_VISIBILITY | |