diff options
Diffstat (limited to 'expr.c')
| -rw-r--r-- | expr.c | 127 |
1 files changed, 108 insertions, 19 deletions
@@ -1,6 +1,6 @@ /* expr.c -- arithmetic expression evaluation. */ -/* Copyright (C) 1990-2010 Free Software Foundation, Inc. +/* Copyright (C) 1990-2013 Free Software Foundation, Inc. This file is part of GNU Bash, the Bourne Again SHell. @@ -63,7 +63,7 @@ Implementation is a recursive-descent parser. Chet Ramey - chet@ins.CWRU.Edu + chet@po.cwru.edu */ #include "config.h" @@ -82,12 +82,13 @@ #include "bashintl.h" #include "shell.h" +#include "typemax.h" /* INTMAX_MAX, INTMAX_MIN */ /* Because of the $((...)) construct, expressions may include newlines. Here is a macro which accepts newlines, tabs and spaces as whitespace. */ #define cr_whitespace(c) (whitespace(c) || ((c) == '\n')) -/* Size be which the expression stack grows when neccessary. */ +/* Size be which the expression stack grows when necessary. */ #define EXPR_STACK_GROW_SIZE 10 /* Maximum amount of recursion allowed. This prevents a non-integer @@ -188,7 +189,9 @@ static void pushexp __P((void)); static void popexp __P((void)); static void expr_unwind __P((void)); static void expr_bind_variable __P((char *, char *)); +#if defined (ARRAY_VARS) static void expr_bind_array_element __P((char *, arrayind_t, char *)); +#endif static intmax_t subexpr __P((char *)); @@ -309,10 +312,15 @@ static void expr_bind_variable (lhs, rhs) char *lhs, *rhs; { - (void)bind_int_variable (lhs, rhs); + SHELL_VAR *v; + + v = bind_int_variable (lhs, rhs); + if (v && (readonly_p (v) || noassign_p (v))) + longjmp (evalbuf, 1); /* variable assignment error */ stupidly_hack_special_variables (lhs); } +#if defined (ARRAY_VARS) /* Rewrite tok, which is of the form vname[expression], to vname[ind], where IND is the already-calculated value of expression. */ static void @@ -333,11 +341,12 @@ expr_bind_array_element (tok, ind, rhs) sprintf (lhs, "%s[%s]", vname, istr); /* XXX */ - expr_bind_variable (lhs, rhs); /*itrace("expr_bind_array_element: %s=%s", lhs, rhs);*/ + expr_bind_variable (lhs, rhs); free (vname); free (lhs); } +#endif /* ARRAY_VARS */ /* Evaluate EXPR, and return the arithmetic result. If VALIDP is non-null, a zero is stored into the location to which it points @@ -366,7 +375,7 @@ evalexp (expr, validp) FASTCOPY (evalbuf, oevalbuf, sizeof (evalbuf)); - c = setjmp (evalbuf); + c = setjmp_nosigs (evalbuf); if (c) { @@ -450,6 +459,9 @@ expassign () register intmax_t value; char *lhs, *rhs; arrayind_t lind; +#if defined (HAVE_IMAXDIV) + imaxdiv_t idiv; +#endif value = expcond (); if (curtok == EQ || curtok == OP_ASSIGN) @@ -468,6 +480,7 @@ expassign () lvalue = value; } + /* XXX - watch out for pointer aliasing issues here */ lhs = savestring (tokstr); /* save ind in case rhs is string var and evaluation overwrites it */ lind = curlval.ind; @@ -490,10 +503,18 @@ expassign () lvalue *= value; break; case DIV: - lvalue /= value; - break; case MOD: - lvalue %= value; + if (lvalue == INTMAX_MIN && value == -1) + lvalue = (op == DIV) ? INTMAX_MIN : 0; + else +#if HAVE_IMAXDIV + { + idiv = imaxdiv (lvalue, value); + lvalue = (op == DIV) ? idiv.quot : idiv.rem; + } +#else + lvalue = (op == DIV) ? lvalue / value : lvalue % value; +#endif break; case PLUS: lvalue += value; @@ -527,16 +548,22 @@ expassign () rhs = itos (value); if (noeval == 0) { +#if defined (ARRAY_VARS) if (lind != -1) expr_bind_array_element (lhs, lind, rhs); else +#endif expr_bind_variable (lhs, rhs); } + if (curlval.tokstr && curlval.tokstr == tokstr) + init_lvalue (&curlval); + free (rhs); free (lhs); FREE (tokstr); tokstr = (char *)NULL; /* For freeing on errors. */ } + return (value); } @@ -654,6 +681,7 @@ expbor () readtok (); val2 = expbxor (); val1 = val1 | val2; + lasttok = NUM; } return (val1); @@ -672,6 +700,7 @@ expbxor () readtok (); val2 = expband (); val1 = val1 ^ val2; + lasttok = NUM; } return (val1); @@ -690,6 +719,7 @@ expband () readtok (); val2 = exp5 (); val1 = val1 & val2; + lasttok = NUM; } return (val1); @@ -712,6 +742,7 @@ exp5 () val1 = (val1 == val2); else if (op == NEQ) val1 = (val1 != val2); + lasttok = NUM; } return (val1); } @@ -740,6 +771,7 @@ exp4 () val1 = val1 < val2; else /* (op == GT) */ val1 = val1 > val2; + lasttok = NUM; } return (val1); } @@ -763,6 +795,7 @@ expshift () val1 = val1 << val2; else val1 = val1 >> val2; + lasttok = NUM; } return (val1); @@ -786,6 +819,7 @@ exp3 () val1 += val2; else if (op == MINUS) val1 -= val2; + lasttok = NUM; } return (val1); } @@ -794,6 +828,9 @@ static intmax_t exp2 () { register intmax_t val1, val2; +#if defined (HAVE_IMAXDIV) + imaxdiv_t idiv; +#endif val1 = exppower (); @@ -802,30 +839,70 @@ exp2 () (curtok == MOD)) { int op = curtok; + char *stp, *sltp; + stp = tp; readtok (); val2 = exppower (); + /* Handle division by 0 and twos-complement arithmetic overflow */ if (((op == DIV) || (op == MOD)) && (val2 == 0)) { if (noeval == 0) - evalerror (_("division by 0")); + { + sltp = lasttp; + lasttp = stp; + while (lasttp && *lasttp && whitespace (*lasttp)) + lasttp++; + evalerror (_("division by 0")); + lasttp = sltp; + } else val2 = 1; } + else if (op == MOD && val1 == INTMAX_MIN && val2 == -1) + { + val1 = 0; + continue; + } + else if (op == DIV && val1 == INTMAX_MIN && val2 == -1) + val2 = 1; if (op == MUL) val1 *= val2; - else if (op == DIV) - val1 /= val2; - else if (op == MOD) - val1 %= val2; + else if (op == DIV || op == MOD) +#if defined (HAVE_IMAXDIV) + { + idiv = imaxdiv (val1, val2); + val1 = (op == DIV) ? idiv.quot : idiv.rem; + } +#else + val1 = (op == DIV) ? val1 / val2 : val1 % val2; +#endif + lasttok = NUM; } return (val1); } static intmax_t +ipow (base, exp) + intmax_t base, exp; +{ + intmax_t result; + + result = 1; + while (exp) + { + if (exp & 1) + result *= base; + exp >>= 1; + base *= base; + } + return result; +} + +static intmax_t exppower () { register intmax_t val1, val2, c; @@ -835,13 +912,12 @@ exppower () { readtok (); val2 = exppower (); /* exponentiation is right-associative */ + lasttok = NUM; if (val2 == 0) return (1); if (val2 < 0) evalerror (_("exponent less than 0")); - for (c = 1; val2--; c *= val1) - ; - val1 = c; + val1 = ipow (val1, val2); } return (val1); } @@ -855,21 +931,25 @@ exp1 () { readtok (); val = !exp1 (); + lasttok = NUM; } else if (curtok == BNOT) { readtok (); val = ~exp1 (); + lasttok = NUM; } else if (curtok == MINUS) { readtok (); val = - exp1 (); + lasttok = NUM; } else if (curtok == PLUS) { readtok (); val = exp1 (); + lasttok = NUM; } else val = exp0 (); @@ -899,9 +979,11 @@ exp0 () vincdec = itos (v2); if (noeval == 0) { +#if defined (ARRAY_VARS) if (curlval.ind != -1) expr_bind_array_element (curlval.tokstr, curlval.ind, vincdec); else +#endif expr_bind_variable (tokstr, vincdec); } free (vincdec); @@ -912,6 +994,7 @@ exp0 () } else if (curtok == LPAR) { + /* XXX - save curlval here? Or entire expression context? */ readtok (); val = EXP_HIGHEST (); @@ -945,9 +1028,11 @@ exp0 () vincdec = itos (v2); if (noeval == 0) { +#if defined (ARRAY_VARS) if (curlval.ind != -1) expr_bind_array_element (curlval.tokstr, curlval.ind, vincdec); else +#endif expr_bind_variable (tokstr, vincdec); } free (vincdec); @@ -955,11 +1040,11 @@ exp0 () } else { + /* XXX - watch out for pointer aliasing issues here */ if (stok == STR) /* free new tokstr before old one is restored */ FREE (tokstr); RESTORETOK (&ec); } - } readtok (); @@ -1048,8 +1133,8 @@ expr_streval (tok, e, lvalue) jump_to_top_level (FORCE_EOF); } - ind = -1; #if defined (ARRAY_VARS) + ind = -1; /* Second argument of 0 to get_array_value means that we don't allow references like array[@]. In this case, get_array_value is just like get_variable_value in that it does not return newly-allocated @@ -1066,7 +1151,11 @@ expr_streval (tok, e, lvalue) lvalue->tokstr = tok; /* XXX */ lvalue->tokval = tval; lvalue->tokvar = v; /* XXX */ +#if defined (ARRAY_VARS) lvalue->ind = ind; +#else + lvalue->ind = -1; +#endif } return (tval); |