fix optimizer bug related to errors and zero-values binding

This commit is contained in:
Matthew Flatt 2017-01-20 12:19:05 -07:00
parent d0b5de398e
commit 8190a7730d
2 changed files with 25 additions and 1 deletions

View File

@ -3884,6 +3884,15 @@
(test-comp '(lambda (f) (letrec ([z (error 'error)] [x #f] [y #f]) #f))
'(lambda (f) (letrec ([z (error 'error)] [x (lambda() y)] [y (lambda () x)]) (f x y z)) 5))
(test-comp '(let-values ([() (error "oops")]) 11)
'(error "oops"))
(test-comp '(let-values ([(x y) (error "oops")]) 11)
'(error "oops"))
(test-comp '(letrec-values ([() (error "oops")]) 11)
'(error "oops"))
(test-comp '(letrec-values ([(x y) (error "oops")]) 11)
'(error "oops"))
(test-comp `(module m racket/base
(define x 5)
(set! x 3)

View File

@ -7210,6 +7210,7 @@ static Scheme_Object *optimize_lets(Scheme_Object *form, Optimize_Info *info, in
Scheme_IR_Let_Header *head = (Scheme_IR_Let_Header *)form;
Scheme_IR_Let_Value *irlv, *pre_body, *retry_start, *prev_body;
Scheme_Object *body, *value, *ready_pairs = NULL, *rp_last = NULL, *ready_pairs_start;
Scheme_Object *escape_body = scheme_false;
Scheme_Once_Used *once_used;
Scheme_Hash_Tree *merge_skip_vars;
int i, j, is_rec, not_simply_let_star = 0, undiscourage, skip_opts = 0;
@ -7486,6 +7487,13 @@ static Scheme_Object *optimize_lets(Scheme_Object *form, Optimize_Info *info, in
here messes up the loop for letrec. So wait and
remove it at the end. */
remove_last_one = 1;
/* If `found_escapes`, either this expression is the
one that escaped, or `value` should have been simplified
to `#f`. So, if it's not `#f`, we'll need to keep
the expression part */
if (!found_escapes)
value = scheme_false;
pre_body->value = value;
} else {
Scheme_IR_Let_Value *naya;
Scheme_Object *rest = pre_body->body;
@ -7804,6 +7812,13 @@ static Scheme_Object *optimize_lets(Scheme_Object *form, Optimize_Info *info, in
if (remove_last_one) {
head->num_clauses -= 1;
body = (Scheme_Object *)pre_body->body;
if (found_escapes && !SCHEME_FALSEP(pre_body->value)) {
/* Since `pre_body->value` wasn't simplified to #f,
keep this as the new body */
escape_body = pre_body->value;
}
if (prev_body) {
prev_body->body = body;
pre_body = prev_body;
@ -7835,7 +7850,7 @@ static Scheme_Object *optimize_lets(Scheme_Object *form, Optimize_Info *info, in
if (!found_escapes) {
body = scheme_optimize_expr(body, body_info, scheme_optimize_tail_context(context));
} else {
body = scheme_false;
body = escape_body;
body_info->single_result = 1;
body_info->preserves_marks = 1;
body_info->escapes = 1;