ack/lang/cem/cemcom/l_ev_ord.c

117 lines
2.5 KiB
C

/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* $Header$ */
/* Lint evaluation order checking */
#include "lint.h"
#ifdef LINT
#include <alloc.h> /* for st_free */
#include "assert.h"
#include "arith.h" /* definition arith */
#include "label.h" /* definition label */
#include "expr.h"
#include "idf.h"
#include "def.h"
#include "code.h" /* RVAL etc */
#include "LLlex.h"
#include "Lpars.h"
#include "stack.h"
#include "type.h"
#include "level.h"
#include "nofloat.h"
#include "l_lint.h"
#include "l_state.h"
extern char *symbol2str();
check_and_merge(espp, esp, com_oper)
struct expr_state **espp, *esp;
{
/* Checks for undefined evaluation orders in case of a commutative operator.
* In addition the sets of used and set variables of both expressions are
* united.
* *espp will be pointing to this new list. esp is used for this list.
*/
register struct expr_state **pp, *p1, *p2;
for (p1 = *espp; p1; p1 = p1->next) {
p2 = esp;
pp = &esp;
while (p2) {
if ( /* p1 and p2 are the same */
p1->es_idf == p2->es_idf
&& p1->es_offset == p2->es_offset
) {
if (com_oper)
check_ev_order(p1, p2, com_oper);
p1->es_used |= p2->es_used;
p1->es_set |= p2->es_set;
*pp = p2->next;
free_expr_state(p2);
p2 = *pp;
}
else {
pp = &p2->next;
p2 = p2->next;
}
}
}
/* The rest of the list esp is pointing to, is put in front of the list
* *espp is now pointing to.
* *espp will be pointing to this new list.
*/
if (!esp)
return;
p1 = *espp;
*espp = esp;
while (esp->next)
esp = esp->next;
esp->next = p1;
}
check_ev_order(esp1, esp2, com_oper)
struct expr_state *esp1, *esp2;
{
if ( (esp1->es_used && esp2->es_set)
|| (esp1->es_set && esp2->es_used)
|| (esp1->es_set && esp2->es_set)
) {
warning("result of %s depends on evaluation order on %s",
symbol2str(com_oper),
esp1->es_idf->id_text);
}
}
add_expr_state(value, to_state, espp)
struct value value;
struct expr_state **espp;
{
register struct expr_state *esp = *espp;
ASSERT(value.vl_class == Name);
while ( esp
&& !( esp->es_idf == value.vl_data.vl_idf
&& esp->es_offset == value.vl_value
)
) {
esp = esp->next;
}
if (!esp) { /* create new expr_state */
esp = new_expr_state();
esp->es_idf = value.vl_data.vl_idf;
esp->es_offset = value.vl_value;
esp->next = *espp;
*espp = esp;
}
if (to_state == SET)
esp->es_set = 1;
else /* USED */
esp->es_used = 1;
}
#endif LINT