Fix the refcount of orig_pkg when type_pkg defaults to it

[perl/modules/Lexical-Types.git] / Types.xs

diff --git a/Types.xs b/Types.xs
index ebfb8a7f1376c939021de932b31334a7245d32b9..8895acb0b371904adb1598074aa80724210154e2 100644 (file)
--- a/Types.xs
+++ b/Types.xs
@@ -6,6 +6,9 @@
 #include "perl.h"
 #include "XSUB.h"
 
+#define __PACKAGE__     "Lexical::Types"
+#define __PACKAGE_LEN__ (sizeof(__PACKAGE__)-1)
+
 /* --- Compatibility wrappers ---------------------------------------------- */
 
 #define LT_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
@@ -32,9 +35,6 @@
 # define HvNAMELEN_get(H) strlen(HvNAME_get(H))
 #endif
 
-#define __PACKAGE__     "Lexical::Types"
-#define __PACKAGE_LEN__ (sizeof(__PACKAGE__)-1)
-
 /* --- Helpers ------------------------------------------------------------- */
 
 /* ... Hints ............................................................... */
@@ -103,8 +103,6 @@ STATIC const lt_op_info *lt_map_fetch(pTHX_ const OP *o) {
 
 /* ... Our pp_padsv ........................................................ */
 
-STATIC OP *(*lt_old_pp_padsv)(pTHX) = 0;
-
 STATIC OP *lt_pp_padsv(pTHX) {
  const lt_op_info *oi;
 
@@ -121,9 +119,9 @@ STATIC OP *lt_pp_padsv(pTHX) {
 
    PUSHMARK(SP);
    EXTEND(SP, 3);
-   PUSHs(sv_2mortal(newSVsv(oi->type_pkg)));
+   PUSHs(oi->type_pkg);
    PUSHs(sv);
-   PUSHs(sv_2mortal(newSVsv(oi->orig_pkg)));
+   PUSHs(oi->orig_pkg);
    PUTBACK;
 
    items = call_sv(oi->type_meth, G_ARRAY | G_METHOD);
@@ -147,7 +145,28 @@ STATIC OP *lt_pp_padsv(pTHX) {
   return CALL_FPTR(oi->pp_padsv)(aTHX);
  }
 
- return CALL_FPTR(lt_old_pp_padsv)(aTHX);
+ return CALL_FPTR(PL_ppaddr[OP_PADSV])(aTHX);
+}
+
+STATIC OP *(*lt_pp_padsv_saved)(pTHX) = 0;
+
+STATIC void lt_pp_padsv_save(void) {
+ if (lt_pp_padsv_saved)
+  return;
+
+ lt_pp_padsv_saved   = PL_ppaddr[OP_PADSV];
+ PL_ppaddr[OP_PADSV] = lt_pp_padsv;
+}
+
+STATIC void lt_pp_padsv_restore(OP *o) {
+ if (!lt_pp_padsv_saved)
+  return;
+
+ if (o->op_ppaddr == lt_pp_padsv)
+  o->op_ppaddr = lt_pp_padsv_saved;
+
+ PL_ppaddr[OP_PADSV] = lt_pp_padsv_saved;
+ lt_pp_padsv_saved   = 0;
 }
 
 /* ... Our ck_pad{any,sv} .................................................. */
@@ -160,7 +179,7 @@ STATIC OP *lt_pp_padsv(pTHX) {
  * pp_padsv, but much less than if we would have set PL_ppaddr[OP_PADSV]
  * globally. */
 
-STATIC U32 lt_TYPEDSCALAR_hash = 0; 
+STATIC SV *lt_default_meth = NULL;
 
 STATIC OP *(*lt_old_ck_padany)(pTHX_ OP *) = 0;
 
@@ -168,20 +187,19 @@ STATIC OP *lt_ck_padany(pTHX_ OP *o) {
  HV *stash;
  SV *hint;
 
- PL_ppaddr[OP_PADSV] = lt_old_pp_padsv;
+ lt_pp_padsv_restore(o);
 
  o = CALL_FPTR(lt_old_ck_padany)(aTHX_ o);
 
  stash = PL_in_my_stash;
  if (stash && (hint = lt_hint())) {
   SV *orig_pkg  = newSVpvn(HvNAME_get(stash), HvNAMELEN_get(stash));
-  SV *orig_meth = newSVpvn_share("TYPEDSCALAR", 11, lt_TYPEDSCALAR_hash);
-  SV *type_pkg  = orig_pkg;
-  SV *type_meth = orig_meth;
+  SV *orig_meth = lt_default_meth;
+  SV *type_pkg  = NULL;
+  SV *type_meth = NULL;
   SV *code      = INT2PTR(SV *, SvUVX(hint));
 
   SvREADONLY_on(orig_pkg);
-  SvREADONLY_on(orig_meth);
 
   if (code) {
    int items;
@@ -201,16 +219,23 @@ STATIC OP *lt_ck_padany(pTHX_ OP *o) {
    SPAGAIN;
    if (items > 2)
     croak(__PACKAGE__ " mangler should return zero, one or two scalars, but got %d", items);
-   if (items) {
+   if (items == 0) {
+    SvREFCNT_dec(orig_pkg);
+    goto skip;
+   } else {
     SV *rsv;
     if (items > 1) {
      rsv = POPs;
-     if (SvOK(rsv))
+     if (SvOK(rsv)) {
       type_meth = newSVsv(rsv);
+      SvREADONLY_on(type_meth);
+     }
     }
     rsv = POPs;
-    if (SvOK(rsv))
+    if (SvOK(rsv)) {
      type_pkg = newSVsv(rsv);
+     SvREADONLY_on(type_pkg);
+    }
    }
    PUTBACK;
 
@@ -218,18 +243,30 @@ STATIC OP *lt_ck_padany(pTHX_ OP *o) {
    LEAVE;
   }
 
-  lt_old_pp_padsv     = PL_ppaddr[OP_PADSV];
-  lt_map_store(o, orig_pkg, type_pkg, type_meth, lt_old_pp_padsv);
-  PL_ppaddr[OP_PADSV] = lt_pp_padsv;
+  if (!type_pkg) {
+   type_pkg = orig_pkg;
+   SvREFCNT_inc(orig_pkg);
+  }
+
+  if (!type_meth) {
+   type_meth = orig_meth;
+   SvREFCNT_inc(orig_meth);
+  }
+
+  lt_pp_padsv_save();
+
+  lt_map_store(o, orig_pkg, type_pkg, type_meth, lt_pp_padsv_saved);
  }
 
+skip:
  return o;
 }
 
 STATIC OP *(*lt_old_ck_padsv)(pTHX_ OP *) = 0;
 
 STATIC OP *lt_ck_padsv(pTHX_ OP *o) {
- PL_ppaddr[OP_PADSV] = lt_old_pp_padsv;
+ lt_pp_padsv_restore(o);
+
  return CALL_FPTR(lt_old_ck_padsv)(aTHX_ o);
 }
 
@@ -244,7 +281,8 @@ PROTOTYPES: DISABLE
 BOOT: 
 {                                    
  if (!lt_initialized++) {
-  PERL_HASH(lt_TYPEDSCALAR_hash, "TYPEDSCALAR", 11);
+  lt_default_meth = newSVpvn("TYPEDSCALAR", 11);
+  SvREADONLY_on(lt_default_meth);
 
   PERL_HASH(lt_hash, __PACKAGE__, __PACKAGE_LEN__);
   lt_op_map = newHV();
@@ -253,7 +291,6 @@ BOOT:
   PL_check[OP_PADANY] = MEMBER_TO_FPTR(lt_ck_padany);
   lt_old_ck_padsv     = PL_check[OP_PADSV];
   PL_check[OP_PADSV]  = MEMBER_TO_FPTR(lt_ck_padsv);
-  lt_old_pp_padsv     = PL_ppaddr[OP_PADSV];
  }
 }