diff options
| -rw-r--r-- | shell/hush.c | 8 | ||||
| -rw-r--r-- | shell/math.c | 120 |
2 files changed, 63 insertions, 65 deletions
diff --git a/shell/hush.c b/shell/hush.c index 752efd0c8..ef0c454ec 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -4728,9 +4728,9 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha if (beg < 0) /* bash compat */ beg = 0; debug_printf_varexp("from val:'%s'\n", val); - if (len == 0 || !val || beg >= strlen(val)) - val = ""; - else { + if (len == 0 || !val || beg >= strlen(val)) { + val = NULL; + } else { /* Paranoia. What if user entered 9999999999999 * which fits in arith_t but not int? */ if (len >= INT_MAX) @@ -4742,7 +4742,7 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha #endif { die_if_script("malformed ${%s:...}", var); - val = ""; + val = NULL; } } else { /* one of "-=+?" */ /* Standard-mandated substitution ops: diff --git a/shell/math.c b/shell/math.c index a4c55a4d0..2f093391f 100644 --- a/shell/math.c +++ b/shell/math.c @@ -124,9 +124,6 @@ #define setvar (math_hooks->setvar ) //#define endofname (math_hooks->endofname) -#define arith_isspace(arithval) \ - (arithval == ' ' || arithval == '\n' || arithval == '\t') - typedef unsigned char operator; /* An operator's token id is a bit of a bitfield. The lower 5 bits are the @@ -156,7 +153,7 @@ typedef unsigned char operator; #define TOK_REM_ASSIGN tok_decl(3,2) /* all assign is right associativity and precedence eq, but (7+3)<<5 > 256 */ -#define convert_prec_is_assing(prec) do { if (prec == 3) prec = 2; } while (0) +#define convert_prec_is_assign(prec) do { if (prec == 3) prec = 2; } while (0) /* conditional is right associativity too */ #define TOK_CONDITIONAL tok_decl(4,0) @@ -223,7 +220,7 @@ tok_have_assign(operator op) { operator prec = PREC(op); - convert_prec_is_assing(prec); + convert_prec_is_assign(prec); return (prec == PREC(TOK_ASSIGN) || prec == PREC_PRE || prec == PREC_POST); } @@ -477,7 +474,7 @@ static const char op_tokens[] ALIGN1 = { 0 }; /* ptr to ")" */ -#define endexpression (&op_tokens[sizeof(op_tokens)-7]) +#define ptr_to_rparen (&op_tokens[sizeof(op_tokens)-7]) const char* FAST_FUNC endofname(const char *name) @@ -494,32 +491,36 @@ endofname(const char *name) arith_t arith(const char *expr, int *perrcode, a_e_h_t *math_hooks) { - char arithval; /* Current character under analysis */ - operator lasttok, op; - operator prec; - operator *stack, *stackptr; - const char *p = endexpression; + operator lasttok; int errcode; - v_n_t *numstack, *numstackptr; - unsigned datasizes = strlen(expr) + 2; - + const char *start_expr = expr = skip_whitespace(expr); + unsigned expr_len = strlen(expr) + 2; /* Stack of integers */ /* The proof that there can be no more than strlen(startbuf)/2+1 integers * in any given correct or incorrect expression is left as an exercise to * the reader. */ - numstackptr = numstack = alloca((datasizes / 2) * sizeof(numstack[0])); + v_n_t *const numstack = alloca((expr_len / 2) * sizeof(numstack[0])); + v_n_t *numstackptr = numstack; /* Stack of operator tokens */ - stackptr = stack = alloca(datasizes * sizeof(stack[0])); + operator *const stack = alloca(expr_len * sizeof(stack[0])); + operator *stackptr = stack; *stackptr++ = lasttok = TOK_LPAREN; /* start off with a left paren */ - *perrcode = errcode = 0; + errcode = 0; while (1) { + const char *p; + operator op; + operator prec; + char arithval; + + expr = skip_whitespace(expr); arithval = *expr; - if (arithval == 0) { - if (p == endexpression) { + if (arithval == '\0') { + if (expr == start_expr) { /* Null expression. */ - return 0; + numstack->val = 0; + goto ret; } /* This is only reached after all tokens have been extracted from the @@ -527,38 +528,29 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks) * are to be applied in order. At the end, there should be a final * result on the integer stack */ - if (expr != endexpression + 1) { + if (expr != ptr_to_rparen + 1) { /* If we haven't done so already, */ /* append a closing right paren */ - expr = endexpression; + expr = ptr_to_rparen; /* and let the loop process it. */ continue; } /* At this point, we're done with the expression. */ - if (numstackptr != numstack+1) { + if (numstackptr != numstack + 1) { /* ... but if there isn't, it's bad */ - err: - *perrcode = -1; - return *perrcode; + goto err; } if (numstack->var) { /* expression is $((var)) only, lookup now */ errcode = arith_lookup_val(numstack, math_hooks); } - ret: - *perrcode = errcode; - return numstack->val; + goto ret; } - /* Continue processing the expression. */ - if (arith_isspace(arithval)) { - /* Skip whitespace */ - goto prologue; - } p = endofname(expr); if (p != expr) { - size_t var_name_size = (p-expr) + 1; /* trailing zero */ - + /* Name */ + size_t var_name_size = (p-expr) + 1; /* +1 for NUL */ numstackptr->var = alloca(var_name_size); safe_strncpy(numstackptr->var, expr, var_name_size); expr = p; @@ -568,36 +560,37 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks) lasttok = TOK_NUM; continue; } + if (isdigit(arithval)) { + /* Number */ numstackptr->var = NULL; errno = 0; - /* call strtoul[l]: */ - numstackptr->val = strto_arith_t(expr, (char **) &expr, 0); + numstackptr->val = strto_arith_t(expr, (char**) &expr, 0); if (errno) numstackptr->val = 0; /* bash compat */ goto num; } - for (p = op_tokens; ; p++) { - const char *o; - if (*p == 0) { - /* strange operator not found */ - goto err; - } - for (o = expr; *p && *o == *p; p++) - o++; - if (!*p) { - /* found */ - expr = o - 1; + /* Should be an operator */ + p = op_tokens; + while (1) { + const char *e = expr; + /* Compare expr to current op_tokens[] element */ + while (*p && *e == *p) + p++, e++; + if (*p == '\0') { /* match: operator is found */ + expr = e; break; } - /* skip tail uncompared token */ + /* Go to next element of op_tokens[] */ while (*p) p++; - /* skip zero delim */ - p++; + p += 2; /* skip NUL and TOK_foo bytes */ + if (*p == '\0') /* no next element, operator not found */ + goto err; } - op = p[1]; + op = p[1]; /* fetch TOK_foo value */ + /* NB: expr now points past the operator */ /* post grammar: a++ reduce to num */ if (lasttok == TOK_POST_INC || lasttok == TOK_POST_DEC) @@ -651,13 +644,12 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks) /* Any operator directly after a */ lasttok = TOK_NUM; /* close paren should consider itself binary */ - goto prologue; + goto next; } } else { operator prev_prec = PREC(stackptr[-1]); - - convert_prec_is_assing(prec); - convert_prec_is_assing(prev_prec); + convert_prec_is_assign(prec); + convert_prec_is_assign(prev_prec); if (prev_prec < prec) break; /* check right assoc */ @@ -665,7 +657,8 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks) break; } errcode = arith_apply(*--stackptr, numstack, &numstackptr, math_hooks); - if (errcode) goto ret; + if (errcode) + goto ret; } if (op == TOK_RPAREN) { goto err; @@ -674,9 +667,14 @@ arith(const char *expr, int *perrcode, a_e_h_t *math_hooks) /* Push this operator to the stack and remember it. */ *stackptr++ = lasttok = op; - prologue: - ++expr; - } /* while */ + next: ; + } /* while (1) */ + + err: + numstack->val = errcode = -1; + ret: + *perrcode = errcode; + return numstack->val; } /* |