/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1996-2013. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
/*
* Function: Provides two primitives: erl_format to build
* Erlang terms in an easy way, and erl_match to perform
* pattern match similar to what is done in Erlang.
*
*/
#include "eidef.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#ifdef VRTX
#define __READY_EXTENSIONS__
#include <errno.h>
#endif
#include "erl_interface.h"
#include "erl_eterm.h"
#include "erl_malloc.h"
#include "erl_error.h"
#include "erl_internal.h"
#define ERL_TRUE 1
#define ERL_FALSE 0
#define ERL_OK 0
#define ERL_FORMAT_ERROR -1
#define ERL_MAX_ENTRIES 255 /* Max entries in a tuple/list term */
#define ERL_MAX_NAME_LENGTH 255 /* Max length of variable names */
#define PRINT(t) \
{ \
print_term(stderr,t); \
fprintf(stderr,"\n"); \
}
typedef struct lvar {
ETERM *var;
struct lvar *next;
} lvar;
/* Forward */
static ETERM *eformat(char**, va_list*);
static int ematch(ETERM*, ETERM*);
/* FIXME not thread safe */
struct _ef {
lvar *chain; /* Chain of local variables */
lvar *idle; /* Idle list of lvar's */
} ef;
/* Find local variable in term.
*/
static ETERM *find_lvar(char *name)
{
lvar *tmp=ef.chain;
while (tmp != NULL) {
if (strcmp(tmp->var->uval.vval.name,name) == 0)
return tmp->var->uval.vval.v;
tmp = tmp->next;
}
return (ETERM *) NULL;
} /* find_lvar */
static void lvar_free(lvar *lv)
{
lvar *tmp=ef.chain;
/* Link in the chain into the idle list */
if (ef.idle == NULL)
ef.idle = lv;
else {
tmp = ef.idle;
while (tmp->next != NULL)
tmp = tmp->next;
tmp->next = lv;
}
/* Clear out the variable information */
tmp = lv;
while (tmp != NULL) {
tmp->var = (ETERM *) NULL;
tmp = tmp->next;
}
} /* lvar_free */
static lvar *lvar_alloc(void)
{
lvar *tmp;
if ((tmp = ef.idle) == NULL) {
tmp = (lvar *) erl_malloc(sizeof(lvar));
}
else {
tmp = ef.idle;
ef.idle = tmp->next;
}
return tmp;
} /* lvar_alloc */
static void undo_bindings(void)
{
lvar *tmp=ef.chain;
while (tmp != NULL) {
erl_free_term(tmp->var->uval.vval.v);
tmp->var->uval.vval.v = (ETERM *) NULL;
tmp = tmp->next;
}
} /* undo_bindings */
static void release_chain(void)
{
lvar_free(ef.chain);
ef.chain = (lvar *) NULL;
} /* release_chain */
static void add_lvar(ETERM *t)
{
lvar *lv;
lv = lvar_alloc();
lv->var = t;
lv->next = ef.chain;
ef.chain = lv;
} /* add_lvar */
static char *pvariable(char **fmt, char *buf)
{
char *start=*fmt;
char c;
int len;
while (1) {
c = *(*fmt)++;
if (isalnum((int) c) || (c == '_'))
continue;
else
break;
}
(*fmt)--;
len = *fmt - start;
memcpy(buf, start, len);
buf[len] = 0;
return buf;
} /* pvariable */
static char *patom(char **fmt, char *buf)
{
char *start=*fmt;
char c;
int len;
while (1) {
c = *(*fmt)++;
if (isalnum((int) c) || (c == '_') || (c == '@'))
continue;
else
break;
}
(*fmt)--;
len = *fmt - start;
memcpy(buf, start, len);
buf[len] = 0;
return buf;
} /* patom */
/* Check if integer or float
*/
static char *pdigit(char **fmt, char *buf)
{
char *start=*fmt;
char c;
int len,dotp=0;
while (1) {
c = *(*fmt)++;
if (isdigit((int) c))
continue;
else if (!dotp && (c == '.')) {
dotp = 1;
continue;
}
else
break;
}
(*fmt)--;
len = *fmt - start;
memcpy(buf, start, len);
buf[len] = 0;
return buf;
} /* pdigit */
static char *pstring(char **fmt, char *buf)
{
char *start=++(*fmt); /* skip first quote */
char c;
int len;
while (1) {
c = *(*fmt)++;
if (c == '"') {
if (*((*fmt)-1) == '\\')
continue;
else
break;
} else
continue;
}
len = *fmt - 1 - start; /* skip last quote */
memcpy(buf, start, len);
buf[len] = 0;
return buf;
} /* pstring */
static char *pquotedatom(char **fmt, char *buf)
{
char *start=++(*fmt); /* skip first quote */
char c;
int len;
while (1) {
c = *(*fmt)++;
if (c == '\'') {
if (*((*fmt)-1) == '\\')
continue;
else
break;
} else
continue;
}
len = *fmt - 1 - start; /* skip last quote */
memcpy(buf, start, len);
buf[len] = 0;
return buf;
} /* pquotedatom */
/*
* The format letters are:
* w - Any Erlang term
* a - An Atom
* b - A Binary
* s - A String
* i - An Integer
* f - A Float (double)
*/
static int pformat(char **fmt, va_list *pap, ETERM *v[], int size)
{
int rc=ERL_OK;
/* this next section hacked to remove the va_arg calls */
switch (*(*fmt)++) {
case 'w':
v[size] = va_arg(*pap, ETERM*);
ERL_COUNT(v[size])++;
break;
case 'a':
v[size] = erl_mk_atom(va_arg(*pap, char *));
break;
case 's':
v[size] = erl_mk_string(va_arg(*pap, char *));
break;
case 'i':
v[size] = erl_mk_int(va_arg(*pap, int));
break;
case 'f':
v[size] = erl_mk_float(va_arg(*pap, double));
break;
case 'b': {
char *sarg = va_arg(*pap, char *);
v[size] = erl_mk_binary(sarg, strlen(sarg));
break;
}
default:
rc = ERL_FORMAT_ERROR;
break;
}
return rc;
} /* pformat */
static int ptuple(char **fmt, va_list *pap, ETERM *v[], int size)
{
int res=ERL_FORMAT_ERROR;
switch (*(*fmt)++) {
case '}':
res = size;
break;
case ',':
res = ptuple(fmt, pap, v, size);
break;
case '~':
if (pformat(fmt, pap, v, size) == ERL_OK)
res = ptuple(fmt, pap, v, ++size);
else
erl_err_msg("ptuple(1): Wrong format sequence !");
break;
case ' ':
return ptuple(fmt, pap, v, size);
break;
default: {
(*fmt)--;
if ((v[size++] = eformat(fmt, pap)) != (ETERM *) NULL)
res = ptuple(fmt, pap, v, size);
break;
/*
if (isupper(**fmt)) {
v[size++] = erl_mk_var(pvariable(fmt, wbuf));
res = ptuple(fmt, pap, v, size);
}
else if ((v[size++] = eformat(fmt, pap)) != (ETERM *) NULL)
res = ptuple(fmt, pap, v, size);
break;
*/
}
} /* switch */
return res;
} /* ptuple */
static int plist(char **fmt, va_list *pap, ETERM *v[], int size)
{
int res=ERL_FORMAT_ERROR;
switch (*(*fmt)++) {
case ']':
res = size;
break;
case ',':
res = plist(fmt, pap, v, size);
break;
case '~':
if (pformat(fmt, pap, v, size) == ERL_OK)
res = plist(fmt, pap, v, ++size);
else
erl_err_msg("plist(1): Wrong format sequence !");
break;
case ' ':
return plist(fmt, pap, v, size);
break;
default: {
(*fmt)--;
if ((v[size++] = eformat(fmt, pap)) != (ETERM *) NULL)
res = plist(fmt, pap, v, size);
break;
/*
if (isupper(**fmt)) {
v[size++] = erl_mk_var(pvariable(fmt, wbuf));
res = plist(fmt, pap, v, size);
}
else if ((v[size++] = eformat(fmt, pap)) != (ETERM *) NULL)
res = plist(fmt, pap, v, size);
break;
*/
}
} /* switch */
return res;
} /* plist */
static ETERM *eformat(char **fmt, va_list *pap)
{
int size;
ETERM *v[ERL_MAX_ENTRIES],*ep;
switch (*(*fmt)++) {
case '{':
if ((size = ptuple(fmt, pap , v, 0)) != ERL_FORMAT_ERROR) {
ep = erl_mk_tuple(v, size);
erl_free_array(v, size);
return ep;
}
else
return (ETERM *) NULL;
break;
case '[':
if (**fmt == ']') {
(*fmt)++;
return erl_mk_empty_list();
} else if ((size = plist(fmt, pap , v, 0)) != ERL_FORMAT_ERROR) {
ep = erl_mk_list(v, size);
erl_free_array(v, size);
return ep;
} else
return (ETERM *) NULL;
break;
case '$': /* char-value? */
return erl_mk_int((int)(*(*fmt)++));
break;
case '~':
if (pformat(fmt, pap, v, 0) == ERL_OK) {
ep = erl_copy_term(v[0]);
erl_free_term(v[0]);
return ep;
}
break;
case ' ':
return eformat(fmt, pap);
break;
/* handle negative numbers too...
* case '-':
* {
* ETERM *tmp;
*
* tmp = eformat(fmt,pap);
* if (ERL_IS_INTEGER(tmp)) ERL_INT_VALUE(tmp) = -(ERL_INT_VALUE(tmp));
* return tmp;
* }
*
*
* break;
*/
default:
{
char wbuf[BUFSIZ]; /* now local to this function for reentrancy */
(*fmt)--;
if (islower((int)**fmt)) { /* atom ? */
char *atom=patom(fmt, wbuf);
return erl_mk_atom(atom);
}
else if (isupper((int)**fmt) || (**fmt == '_')) {
char *var=pvariable(fmt, wbuf);
return erl_mk_var(var);
}
else if (isdigit((int)**fmt)) { /* integer/float ? */
char *digit=pdigit(fmt, wbuf);
if (strchr(digit,(int) '.') == NULL)
return erl_mk_int(atoi((const char *) digit));
else
return erl_mk_float(atof((const char *) digit));
}
else if (**fmt == '"') { /* string ? */
char *string=pstring(fmt, wbuf);
return erl_mk_string(string);
}
else if (**fmt == '\'') { /* quoted atom ? */
char *qatom=pquotedatom(fmt, wbuf);
return erl_mk_atom(qatom);
}
}
break;
}
erl_err_msg("<ERROR> Syntax error in eformat, char was: %c !", **fmt);
return (ETERM *) NULL;
} /* eformat */
ETERM *erl_format(char *fmt, ... )
{
ETERM *res=NULL;
va_list ap;
va_start(ap, fmt);
res = eformat(&fmt, &ap);
va_end(ap);
return res;
} /* erl_format */
/*
* Perform a pattern match between a pattern p and a term t.
* As a side effect bind any unbound variables in p.
* Return true or false.
*/
static int ematch(ETERM *p, ETERM *t)
{
unsigned int type_p;
unsigned int type_t;
ETERM *tmp;
/* two NULLs are equal, one is not... */
if (!p && !t) return ERL_TRUE;
if (!p || !t) return ERL_FALSE;
/*
* ASSERT(p != NULL);
* ASSERT(t != NULL);
*/
type_p = ERL_TYPE(p);
type_t = ERL_TYPE(t);
if (type_t == ERL_VARIABLE) {
if (t->uval.vval.v == NULL)
return ERL_FALSE; /* Can't have an unbound variable here ! */
else
t = t->uval.vval.v;
}
if (type_p != ERL_VARIABLE && type_p != type_t)
return ERL_FALSE;
switch (type_p) {
case ERL_ATOM: {
Erl_Atom_data* pa = &p->uval.aval.d;
Erl_Atom_data* ta = &t->uval.aval.d;
if (pa->utf8 && ta->utf8) {
return pa->lenU == ta->lenU && memcmp(pa->utf8, ta->utf8, pa->lenU)==0;
}
else if (pa->latin1 && ta->latin1) {
return pa->lenL == ta->lenL && memcmp(pa->latin1, ta->latin1, pa->lenL)==0;
}
else if (pa->latin1) {
return cmp_latin1_vs_utf8(pa->latin1, pa->lenL, ta->utf8, ta->lenU)==0;
}
else {
return cmp_latin1_vs_utf8(ta->latin1, ta->lenL, pa->utf8, pa->lenU)==0;
}
}
case ERL_VARIABLE:
if (strcmp(p->uval.vval.name, "_") == 0) /* anon. variable */
return ERL_TRUE;
else if ((tmp = find_lvar(p->uval.vval.name)) != (ETERM *) NULL) {
/* v points to NULL in cases like erl_format("{X,X}") for the
second variable */
if (p->uval.vval.v == NULL)
p->uval.vval.v = erl_copy_term(tmp);
return ematch(p->uval.vval.v, t);
}
else {
/* check if the variable is bound already */
if (p->uval.vval.v != NULL) {
if (ematch(p->uval.vval.v, t) == ERL_TRUE ){
add_lvar(p);
return ERL_TRUE;
}
else
return ERL_FALSE;
}
else {
p->uval.vval.v = erl_copy_term(t);
add_lvar(p);
return ERL_TRUE;
}
}
break;
case ERL_PID:
if ((strcmp(ERL_PID_NODE(p), ERL_PID_NODE(t)) == 0) &&
(ERL_PID_NUMBER(p) == ERL_PID_NUMBER(t)) &&
(ERL_PID_SERIAL(p) == ERL_PID_SERIAL(t)) &&
(ERL_PID_CREATION(p) == ERL_PID_CREATION(t)))
return ERL_TRUE;
else
return ERL_FALSE;
break;
case ERL_PORT:
if ((strcmp(ERL_PORT_NODE(p), ERL_PORT_NODE(t)) == 0) &&
(ERL_PORT_NUMBER(p) == ERL_PORT_NUMBER(t)) &&
(ERL_PORT_CREATION(p) == ERL_PORT_CREATION(t)))
return ERL_TRUE;
else
return ERL_FALSE;
break;
case ERL_REF: {
int i, len;
if (strcmp(ERL_REF_NODE(p), ERL_REF_NODE(t)) != 0 ||
ERL_REF_CREATION(p) != ERL_REF_CREATION(t))
return ERL_FALSE;
/* FIXME: {len=1, n={42}} and {len=3, n={42, 17, 13}} tests equal. */
len = ERL_REF_LEN(p);
if (len > ERL_REF_LEN(t))
len = ERL_REF_LEN(t);
for (i = 0; i < len; i++)
if (ERL_REF_NUMBERS(p)[i] != ERL_REF_NUMBERS(t)[i])
return ERL_FALSE;
return ERL_TRUE;
break;
}
case ERL_EMPTY_LIST:
return ERL_TRUE;
case ERL_LIST:
while (ERL_IS_CONS(p) && ERL_IS_CONS(t)) {
if (ematch(p->uval.lval.head, t->uval.lval.head) == ERL_FALSE)
return ERL_FALSE;
p = p->uval.lval.tail;
t = t ->uval.lval.tail;
}
return ematch(p, t);
case ERL_TUPLE:
{
int i;
if (erl_size(p) != erl_size(t))
return ERL_FALSE;
else {
for(i=0; i<erl_size(p); i++)
if (ematch(p->uval.tval.elems[i],t->uval.tval.elems[i]) == ERL_FALSE)
return ERL_FALSE;
return ERL_TRUE;
}
}
break;
case ERL_BINARY:
{
int i;
if ((i = p->uval.bval.size) != t->uval.bval.size)
return ERL_FALSE;
else
return (memcmp(p->uval.bval.b,t->uval.bval.b,i)==0) ? ERL_TRUE : ERL_FALSE;
}
break;
case ERL_INTEGER:
return (p->uval.ival.i == t->uval.ival.i) ? ERL_TRUE : ERL_FALSE;
break;
case ERL_SMALL_BIG:
case ERL_U_SMALL_BIG:
/* This case can't happend since it is impossible
* to create a bignum from the C code.
*/
return ERL_FALSE;
break;
case ERL_FLOAT:
#if defined(VXWORKS) && CPU == PPC860
{
return (erl_fp_compare((unsigned *)&(p->uval.fval.f),
(unsigned *)&(t->uval.fval.f)) == 0)
? ERL_TRUE : ERL_FALSE;
}
#else
return (p->uval.fval.f == t->uval.fval.f) ? ERL_TRUE : ERL_FALSE;
#endif
break;
default:
return ERL_FALSE;
break;
}
/* erl_err_msg("ematch: Unknown type == %c\n", type_p); */
return ERL_FALSE;
} /* ematch */
int erl_match(ETERM *p, ETERM *t)
{
int i;
if ((i = ematch(p, t)) == ERL_FALSE)
undo_bindings();
release_chain();
return i;
} /* erl_match */
