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shell/math: do not accept $((36#@))

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function                                             old     new   delta
parse_with_base                                      170     174      +4
arith_apply                                          996     991      -5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 4/-5)               Total: -1 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2023-07-02 17:58:20 +02:00
parent 38f769ab4e
commit 045924ed7d
1 changed files with 22 additions and 16 deletions
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38
shell/math.c
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@ -128,7 +128,8 @@ typedef unsigned char operator;
* Consider * and / * Consider * and /
*/ */
#define tok_decl(prec,id) (((id)<<5) | (prec)) #define tok_decl(prec,id) (((id)<<5) | (prec))
#define PREC(op) ((op) & 0x1F) #define ID_SHIFT 5
#define PREC(op) ((op) & 0x1f)
#define PREC_LPAREN 0 #define PREC_LPAREN 0
#define TOK_LPAREN tok_decl(0,0) #define TOK_LPAREN tok_decl(0,0)
@ -146,14 +147,16 @@ typedef unsigned char operator;
#define TOK_AND_ASSIGN tok_decl(2,1) #define TOK_AND_ASSIGN tok_decl(2,1)
#define TOK_OR_ASSIGN tok_decl(2,2) #define TOK_OR_ASSIGN tok_decl(2,2)
#define TOK_XOR_ASSIGN tok_decl(2,3) #define TOK_XOR_ASSIGN tok_decl(2,3)
#define TOK_PLUS_ASSIGN tok_decl(2,4) #define TOK_ADD_ASSIGN tok_decl(2,4)
#define TOK_MINUS_ASSIGN tok_decl(2,5) #define TOK_SUB_ASSIGN tok_decl(2,5)
#define TOK_LSHIFT_ASSIGN tok_decl(2,6) #define TOK_LSHIFT_ASSIGN tok_decl(2,6)
#define TOK_RSHIFT_ASSIGN tok_decl(2,7) #define TOK_RSHIFT_ASSIGN tok_decl(2,7)
#define PREC_ASSIGN2 3 #define PREC_ASSIGN2 3
#define TOK_MUL_ASSIGN tok_decl(3,0) #define TOK_MUL_ASSIGN tok_decl(3,0)
#define TOK_DIV_ASSIGN tok_decl(3,1) /* "/" and "/=" ops have the same id bits */
#define DIV_ID1 1
#define TOK_DIV_ASSIGN tok_decl(3,DIV_ID1)
#define TOK_REM_ASSIGN tok_decl(3,2) #define TOK_REM_ASSIGN tok_decl(3,2)
#define fix_assignment_prec(prec) do { prec -= (prec == 3); } while (0) #define fix_assignment_prec(prec) do { prec -= (prec == 3); } while (0)
@ -198,7 +201,7 @@ typedef unsigned char operator;
#define TOK_SUB tok_decl(13,1) #define TOK_SUB tok_decl(13,1)
#define TOK_MUL tok_decl(14,0) #define TOK_MUL tok_decl(14,0)
#define TOK_DIV tok_decl(14,1) #define TOK_DIV tok_decl(14,DIV_ID1)
#define TOK_REM tok_decl(14,2) #define TOK_REM tok_decl(14,2)
/* Exponent is right associative */ /* Exponent is right associative */
@ -408,9 +411,9 @@ arith_apply(arith_state_t *math_state, operator op, var_or_num_t *numstack, var_
rez = (rez <= right_side_val); rez = (rez <= right_side_val);
else if (op == TOK_MUL || op == TOK_MUL_ASSIGN) else if (op == TOK_MUL || op == TOK_MUL_ASSIGN)
rez *= right_side_val; rez *= right_side_val;
else if (op == TOK_ADD || op == TOK_PLUS_ASSIGN) else if (op == TOK_ADD || op == TOK_ADD_ASSIGN)
rez += right_side_val; rez += right_side_val;
else if (op == TOK_SUB || op == TOK_MINUS_ASSIGN) else if (op == TOK_SUB || op == TOK_SUB_ASSIGN)
rez -= right_side_val; rez -= right_side_val;
else if (op == TOK_ASSIGN || op == TOK_COMMA) else if (op == TOK_ASSIGN || op == TOK_COMMA)
rez = right_side_val; rez = right_side_val;
@ -439,11 +442,11 @@ arith_apply(arith_state_t *math_state, operator op, var_or_num_t *numstack, var_
* Make sure to at least not SEGV here: * Make sure to at least not SEGV here:
*/ */
if (right_side_val == -1 if (right_side_val == -1
&& rez << 1 == 0 /* MAX_NEGATIVE_INT or 0 */ && (rez << 1) == 0 /* MAX_NEGATIVE_INT or 0 */
) { ) {
right_side_val = 1; right_side_val = 1;
} }
if (op == TOK_DIV || op == TOK_DIV_ASSIGN) if (op & (DIV_ID1 << ID_SHIFT)) /* DIV or DIV_ASSIGN? */
rez /= right_side_val; rez /= right_side_val;
else else
rez %= right_side_val; rez %= right_side_val;
@ -505,8 +508,8 @@ static const char op_tokens[] ALIGN1 = {
'*','=', 0, TOK_MUL_ASSIGN, '*','=', 0, TOK_MUL_ASSIGN,
'/','=', 0, TOK_DIV_ASSIGN, '/','=', 0, TOK_DIV_ASSIGN,
'%','=', 0, TOK_REM_ASSIGN, '%','=', 0, TOK_REM_ASSIGN,
'+','=', 0, TOK_PLUS_ASSIGN, '+','=', 0, TOK_ADD_ASSIGN,
'-','=', 0, TOK_MINUS_ASSIGN, '-','=', 0, TOK_SUB_ASSIGN,
'-','-', 0, TOK_POST_DEC, '-','-', 0, TOK_POST_DEC,
'^','=', 0, TOK_XOR_ASSIGN, '^','=', 0, TOK_XOR_ASSIGN,
'+','+', 0, TOK_POST_INC, '+','+', 0, TOK_POST_INC,
@ -542,12 +545,15 @@ static arith_t parse_with_base(const char *nptr, char **endptr, unsigned base)
for (;;) { for (;;) {
unsigned digit = (unsigned)*nptr - '0'; unsigned digit = (unsigned)*nptr - '0';
if (digit >= 10 /* not 0..9 */ if (digit >= 10 /* not 0..9 */
&& digit <= 'z' - '0' /* needed to reject e.g. $((64#~)) */ && digit <= 'z' - '0' /* reject e.g. $((64#~)) */
) { ) {
/* in bases up to 36, case does not matter for a-z */ /* current char is one of :;<=>?@A..Z[\]^_`a..z */
/* in bases up to 36, case does not matter for a-z,
* map A..Z and a..z to 10..35: */
digit = (unsigned)(*nptr | 0x20) - ('a' - 10); digit = (unsigned)(*nptr | 0x20) - ('a' - 10);
if (base > 36 && *nptr <= '_') { if (base > 36 && *nptr <= '_') {
/* otherwise, A-Z,@,_ are 36-61,62,63 */ /* base > 36: A-Z,@,_ are 36-61,62,63 */
if (*nptr == '_') if (*nptr == '_')
digit = 63; digit = 63;
else if (*nptr == '@') else if (*nptr == '@')
@ -558,8 +564,8 @@ static arith_t parse_with_base(const char *nptr, char **endptr, unsigned base)
break; /* error: one of [\]^ */ break; /* error: one of [\]^ */
} }
//bb_error_msg("ch:'%c'%d digit:%u", *nptr, *nptr, digit); //bb_error_msg("ch:'%c'%d digit:%u", *nptr, *nptr, digit);
//if (digit < 10) - example where we need this? if (digit < 10) /* reject e.g. $((36#@)) */
// break; break;
} }
if (digit >= base) if (digit >= base)
break; break;