/* 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.
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 */
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 *));
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 *));
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. */
(X)->tokval = tokval; \
(X)->tokstr = tokstr; \
(X)->noeval = noeval; \
+ (X)->lval = curlval; \
} while (0)
#define RESTORETOK(X) \
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
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
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 ();
{
register intmax_t value;
char *lhs, *rhs;
+ arrayind_t lind;
value = expcond ();
if (curtok == EQ || curtok == OP_ASSIGN)
}
lhs = savestring (tokstr);
+ /* save ind in case rhs is string var and evaluation overwrites it */
+ lind = curlval.ind;
readtok ();
value = 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);
readtok ();
val = ~exp1 ();
}
+ else if (curtok == MINUS)
+ {
+ readtok ();
+ val = - exp1 ();
+ }
+ else if (curtok == PLUS)
+ {
+ readtok ();
+ val = exp1 ();
+ }
else
val = 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 ();
/* 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 */
}
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)
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);
}
register char *cp, *xp;
register unsigned char c, c1;
register int e;
+ struct lvalue lval;
/* Skip leading whitespace. */
cp = tp;
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;
/* 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;
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