diff options
Diffstat (limited to 'expr.c')
| -rw-r--r-- | expr.c | 178 |
1 files changed, 142 insertions, 36 deletions
@@ -1,6 +1,6 @@ /* expr.c -- arithmetic expression evaluation. */ -/* Copyright (C) 1990-2009 Free Software Foundation, Inc. +/* Copyright (C) 1990-2010 Free Software Foundation, Inc. This file is part of GNU Bash, the Bourne Again SHell. @@ -137,6 +137,28 @@ highest precedence. */ #define EXP_HIGHEST expcomma +#ifndef MAX_INT_LEN +# define MAX_INT_LEN 32 +#endif + +struct lvalue +{ + char *tokstr; /* possibly-rewritten lvalue if not NULL */ + intmax_t tokval; /* expression evaluated value */ + SHELL_VAR *tokvar; /* variable described by array or var reference */ + intmax_t ind; /* array index if not -1 */ +}; + +/* A structure defining a single expression context. */ +typedef struct { + int curtok, lasttok; + char *expression, *tp, *lasttp; + intmax_t tokval; + char *tokstr; + int noeval; + struct lvalue lval; +} EXPR_CONTEXT; + static char *expression; /* The current expression */ static char *tp; /* token lexical position */ static char *lasttp; /* pointer to last token position */ @@ -148,10 +170,17 @@ static intmax_t tokval; /* current token value */ static int noeval; /* set to 1 if no assignment to be done */ static procenv_t evalbuf; +static struct lvalue curlval = {0, 0, 0, -1}; +static struct lvalue lastlval = {0, 0, 0, -1}; + static int _is_arithop __P((int)); static void readtok __P((void)); /* lexical analyzer */ -static intmax_t expr_streval __P((char *, int)); +static void init_lvalue __P((struct lvalue *)); +static struct lvalue *alloc_lvalue __P((void)); +static void free_lvalue __P((struct lvalue *)); + +static intmax_t expr_streval __P((char *, int, struct lvalue *)); static intmax_t strlong __P((char *)); static void evalerror __P((const char *)); @@ -159,6 +188,7 @@ static void pushexp __P((void)); static void popexp __P((void)); static void expr_unwind __P((void)); static void expr_bind_variable __P((char *, char *)); +static void expr_bind_array_element __P((char *, arrayind_t, char *)); static intmax_t subexpr __P((char *)); @@ -179,23 +209,6 @@ static intmax_t exppower __P((void)); static intmax_t exp1 __P((void)); static intmax_t exp0 __P((void)); -/* A structure defining a single expression context. */ -typedef struct { - int curtok, lasttok; - char *expression, *tp, *lasttp; - intmax_t tokval; - char *tokstr; - int noeval; -} EXPR_CONTEXT; - -#ifdef INCLUDE_UNUSED -/* Not used yet. */ -typedef struct { - char *tokstr; - intmax_t tokval; -} LVALUE; -#endif - /* Global var which contains the stack of expression contexts. */ static EXPR_CONTEXT **expr_stack; static int expr_depth; /* Location in the stack. */ @@ -217,6 +230,7 @@ extern const char * const bash_badsub_errmsg; (X)->tokval = tokval; \ (X)->tokstr = tokstr; \ (X)->noeval = noeval; \ + (X)->lval = curlval; \ } while (0) #define RESTORETOK(X) \ @@ -228,6 +242,7 @@ extern const char * const bash_badsub_errmsg; tokval = (X)->tokval; \ tokstr = (X)->tokstr; \ noeval = (X)->noeval; \ + curlval = (X)->lval; \ } while (0) /* Push and save away the contents of the globals describing the @@ -298,6 +313,32 @@ expr_bind_variable (lhs, rhs) stupidly_hack_special_variables (lhs); } +/* Rewrite tok, which is of the form vname[expression], to vname[ind], where + IND is the already-calculated value of expression. */ +static void +expr_bind_array_element (tok, ind, rhs) + char *tok; + arrayind_t ind; + char *rhs; +{ + char *lhs, *vname; + size_t llen; + char ibuf[INT_STRLEN_BOUND (arrayind_t) + 1], *istr; + + istr = fmtumax (ind, 10, ibuf, sizeof (ibuf), 0); + vname = array_variable_name (tok, (char **)NULL, (int *)NULL); + + llen = strlen (vname) + sizeof (ibuf) + 3; + lhs = xmalloc (llen); + + sprintf (lhs, "%s[%s]", vname, istr); /* XXX */ + + expr_bind_variable (lhs, rhs); +/*itrace("expr_bind_array_element: %s=%s", lhs, rhs);*/ + free (vname); + free (lhs); +} + /* Evaluate EXPR, and return the arithmetic result. If VALIDP is non-null, a zero is stored into the location to which it points if the expression is invalid, non-zero otherwise. If a non-zero @@ -364,12 +405,14 @@ subexpr (expr) return (0); pushexp (); - curtok = lasttok = 0; expression = savestring (expr); tp = expression; + curtok = lasttok = 0; tokstr = (char *)NULL; tokval = 0; + init_lvalue (&curlval); + lastlval = curlval; readtok (); @@ -406,6 +449,7 @@ expassign () { register intmax_t value; char *lhs, *rhs; + arrayind_t lind; value = expcond (); if (curtok == EQ || curtok == OP_ASSIGN) @@ -425,6 +469,8 @@ expassign () } lhs = savestring (tokstr); + /* save ind in case rhs is string var and evaluation overwrites it */ + lind = curlval.ind; readtok (); value = expassign (); @@ -476,7 +522,12 @@ expassign () rhs = itos (value); if (noeval == 0) - expr_bind_variable (lhs, rhs); + { + if (lind != -1) + expr_bind_array_element (lhs, lind, rhs); + else + expr_bind_variable (lhs, rhs); + } free (rhs); free (lhs); FREE (tokstr); @@ -801,6 +852,16 @@ exp1 () readtok (); val = ~exp1 (); } + else if (curtok == MINUS) + { + readtok (); + val = - exp1 (); + } + else if (curtok == PLUS) + { + readtok (); + val = exp1 (); + } else val = exp0 (); @@ -828,23 +889,18 @@ exp0 () v2 = tokval + ((stok == PREINC) ? 1 : -1); vincdec = itos (v2); if (noeval == 0) - expr_bind_variable (tokstr, vincdec); + { + if (curlval.ind != -1) + expr_bind_array_element (curlval.tokstr, curlval.ind, vincdec); + else + expr_bind_variable (tokstr, vincdec); + } free (vincdec); val = v2; curtok = NUM; /* make sure --x=7 is flagged as an error */ readtok (); } - else if (curtok == MINUS) - { - readtok (); - val = - exp0 (); - } - else if (curtok == PLUS) - { - readtok (); - val = exp0 (); - } else if (curtok == LPAR) { readtok (); @@ -873,12 +929,18 @@ exp0 () /* restore certain portions of EC */ tokstr = ec.tokstr; noeval = ec.noeval; + curlval = ec.lval; lasttok = STR; /* ec.curtok */ v2 = val + ((stok == POSTINC) ? 1 : -1); vincdec = itos (v2); if (noeval == 0) - expr_bind_variable (tokstr, vincdec); + { + if (curlval.ind != -1) + expr_bind_array_element (curlval.tokstr, curlval.ind, vincdec); + else + expr_bind_variable (tokstr, vincdec); + } free (vincdec); curtok = NUM; /* make sure x++=7 is flagged as an error */ } @@ -899,14 +961,44 @@ exp0 () return (val); } +static void +init_lvalue (lv) + struct lvalue *lv; +{ + lv->tokstr = 0; + lv->tokvar = 0; + lv->tokval = lv->ind = -1; +} + +static struct lvalue * +alloc_lvalue () +{ + struct lvalue *lv; + + lv = xmalloc (sizeof (struct lvalue)); + init_lvalue (lv); + return (lv); +} + +static void +free_lvalue (lv) + struct lvalue *lv; +{ + free (lv); /* should be inlined */ +} + static intmax_t -expr_streval (tok, e) +expr_streval (tok, e, lvalue) char *tok; int e; + struct lvalue *lvalue; { SHELL_VAR *v; char *value; intmax_t tval; +#if defined (ARRAY_VARS) + arrayind_t ind; +#endif /* [[[[[ */ #if defined (ARRAY_VARS) @@ -941,18 +1033,27 @@ expr_streval (tok, e) jump_to_top_level (FORCE_EOF); } + ind = -1; #if defined (ARRAY_VARS) /* 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 memory or quote the results. */ - value = (e == ']') ? get_array_value (tok, 0, (int *)NULL) : get_variable_value (v); + value = (e == ']') ? get_array_value (tok, 0, (int *)NULL, &ind) : get_variable_value (v); #else value = get_variable_value (v); #endif tval = (value && *value) ? subexpr (value) : 0; + if (lvalue) + { + lvalue->tokstr = tok; /* XXX */ + lvalue->tokval = tval; + lvalue->tokvar = v; /* XXX */ + lvalue->ind = ind; + } + return (tval); } @@ -1024,6 +1125,7 @@ readtok () register char *cp, *xp; register unsigned char c, c1; register int e; + struct lvalue lval; /* Skip leading whitespace. */ cp = tp; @@ -1075,6 +1177,7 @@ readtok () tokstr = savestring (tp); *cp = c; + /* XXX - make peektok part of saved token state? */ SAVETOK (&ec); tokstr = (char *)NULL; /* keep it from being freed */ tp = savecp = cp; @@ -1090,7 +1193,10 @@ readtok () /* The tests for PREINC and PREDEC aren't strictly correct, but they preserve old behavior if a construct like --x=9 is given. */ if (lasttok == PREINC || lasttok == PREDEC || peektok != EQ) - tokval = expr_streval (tokstr, e); + { + lastlval = curlval; + tokval = expr_streval (tokstr, e, &curlval); + } else tokval = 0; |