register destructor for the generated optree in case of exceptions

diff --git a/Parameters.xs b/Parameters.xs
index 5372f04..8e91f76 100644 (file)
--- a/Parameters.xs
+++ b/Parameters.xs
@@ -498,7 +498,11 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
 
        /* munge */
        {
-               OP *prelude = NULL;
+               OP **prelude_sentinel = NULL;
+
+               Newx(prelude_sentinel, 1, OP *);
+               *prelude_sentinel = NULL;
+               SAVEDESTRUCTOR_X(free_ptr_op, prelude_sentinel);
 
                /* min/max argument count checks */
                if (spec->flags & FLAG_CHECK_NARGS) {
@@ -525,7 +529,7 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
                                                newSVOP(OP_CONST, 0, newSViv(args_min)));
                                chk = newLOGOP(OP_AND, 0, cond, err);
 
-                               prelude = op_append_list(OP_LINESEQ, prelude, newSTATEOP(0, NULL, chk));
+                               *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
                        }
                        if (args_max != -1) {
                                OP *chk, *cond, *err, *croak;
@@ -543,7 +547,7 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
                                                newSVOP(OP_CONST, 0, newSViv(args_max)));
                                chk = newLOGOP(OP_AND, 0, cond, err);
 
-                               prelude = op_append_list(OP_LINESEQ, prelude, newSTATEOP(0, NULL, chk));
+                               *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
                        }
                }
 
@@ -555,7 +559,7 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
                        var->op_targ = pad_add_name_sv(spec->shift, 0, NULL, NULL);
 
                        shift = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
-                       prelude = op_append_list(OP_LINESEQ, prelude, newSTATEOP(0, NULL, shift));
+                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, shift));
                }
 
                /* my (PARAMS) = @_; */
@@ -576,7 +580,7 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
                        init_param = newASSIGNOP(OPf_STACKED, left, 0, right);
                        init_param = newSTATEOP(0, NULL, init_param);
 
-                       prelude = op_append_list(OP_LINESEQ, prelude, init_param);
+                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, init_param);
                }
 
                /* defaults */
@@ -610,7 +614,7 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
                                dp->init = NULL;
                        }
 
-                       prelude = op_append_list(OP_LINESEQ, prelude, gen);
+                       *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, gen);
                }
 
                /* finally let perl parse the actual subroutine body */
@@ -619,11 +623,12 @@ static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len
                /* add '();' to make function return nothing by default */
                /* (otherwise the invisible parameter initialization can "leak" into
                   the return value: fun ($x) {}->("asdf", 0) == 2) */
-               if (prelude) {
+               if (*prelude_sentinel) {
                        body = newSTATEOP(0, NULL, body);
                }
 
-               body = op_append_list(OP_LINESEQ, prelude, body);
+               body = op_append_list(OP_LINESEQ, *prelude_sentinel, body);
+               *prelude_sentinel = NULL;
        }
 
        /* it's go time. */