045924ed7
Denys Vlasenko
2023-07-02
Subject
shell/math: do not accept $((36#@))
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Commit Diff GitHub →
shell/math.c+22 -16
| @@ -128,7 +128,8 @@ typedef unsigned char operator; | |
| * Consider * and / | |
| */ | |
| #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 TOK_LPAREN tok_decl(0,0) | |
| @@ -146,14 +147,16 @@ typedef unsigned char operator; | |
| #define TOK_AND_ASSIGN tok_decl(2,1) | |
| #define TOK_OR_ASSIGN tok_decl(2,2) | |
| #define TOK_XOR_ASSIGN tok_decl(2,3) | |
| - | #define TOK_PLUS_ASSIGN tok_decl(2,4) |
| - | #define TOK_MINUS_ASSIGN tok_decl(2,5) |
| + | #define TOK_ADD_ASSIGN tok_decl(2,4) |
| + | #define TOK_SUB_ASSIGN tok_decl(2,5) |
| #define TOK_LSHIFT_ASSIGN tok_decl(2,6) | |
| #define TOK_RSHIFT_ASSIGN tok_decl(2,7) | |
| #define PREC_ASSIGN2 3 | |
| #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 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_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) | |
| /* 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); | |
| else if (op == TOK_MUL || op == TOK_MUL_ASSIGN) | |
| 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; | |
| - | else if (op == TOK_SUB || op == TOK_MINUS_ASSIGN) |
| + | else if (op == TOK_SUB || op == TOK_SUB_ASSIGN) |
| rez -= right_side_val; | |
| else if (op == TOK_ASSIGN || op == TOK_COMMA) | |
| 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: | |
| */ | |
| 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; | |
| } | |
| - | if (op == TOK_DIV || op == TOK_DIV_ASSIGN) |
| + | if (op & (DIV_ID1 << ID_SHIFT)) /* DIV or DIV_ASSIGN? */ |
| rez /= right_side_val; | |
| else | |
| rez %= right_side_val; | |
| @@ -505,8 +508,8 @@ static const char op_tokens[] ALIGN1 = { | |
| '*','=', 0, TOK_MUL_ASSIGN, | |
| '/','=', 0, TOK_DIV_ASSIGN, | |
| '%','=', 0, TOK_REM_ASSIGN, | |
| - | '+','=', 0, TOK_PLUS_ASSIGN, |
| - | '-','=', 0, TOK_MINUS_ASSIGN, |
| + | '+','=', 0, TOK_ADD_ASSIGN, |
| + | '-','=', 0, TOK_SUB_ASSIGN, |
| '-','-', 0, TOK_POST_DEC, | |
| '^','=', 0, TOK_XOR_ASSIGN, | |
| '+','+', 0, TOK_POST_INC, | |
| @@ -542,12 +545,15 @@ static arith_t parse_with_base(const char *nptr, char **endptr, unsigned base) | |
| for (;;) { | |
| unsigned digit = (unsigned)*nptr - '0'; | |
| 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 :;<=>[email protected][\]^_`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); | |
| if (base > 36 && *nptr <= '_') { | |
| - | /* otherwise, A-Z,@,_ are 36-61,62,63 */ |
| + | /* base > 36: A-Z,@,_ are 36-61,62,63 */ |
| if (*nptr == '_') | |
| digit = 63; | |
| else if (*nptr == '@') | |
| @@ -558,8 +564,8 @@ static arith_t parse_with_base(const char *nptr, char **endptr, unsigned base) | |
| break; /* error: one of [\]^ */ | |
| } | |
| //bb_error_msg("ch:'%c'%d digit:%u", *nptr, *nptr, digit); | |
| - | //if (digit < 10) - example where we need this? |
| - | // break; |
| + | if (digit < 10) /* reject e.g. $((36#@)) */ |
| + | break; |
| } | |
| if (digit >= base) | |
| break; | |