Flag ops that are on the savestack

This is to allow future commits to free dangling ops after errors.

If an op is on the savestack, then it is going to be freed by scope.c,
and op_free must not be called on it by anyone else.

So we flag such ops new.

diff --git a/op.h b/op.h
index 7be9bf5..7e20c70 100644 (file)
--- a/op.h
+++ b/op.h
@@ -28,8 +28,9 @@
  *                     the op may be safely op_free()d multiple times
  *     op_latefreed    an op_latefree op has been op_free()d
  *     op_attached     this op (sub)tree has been attached to a CV
+ *     op_savefree     on savestack via SAVEFREEOP
  *
- *     op_spare        three spare bits!
+ *     op_spare        two spare bits!
  *     op_flags        Flags common to all operations.  See OPf_* below.
  *     op_private      Flags peculiar to a particular operation (BUT,
  *                     by default, set to the number of children until
@@ -62,7 +63,8 @@ typedef PERL_BITFIELD16 Optype;
     PERL_BITFIELD16 op_latefree:1;     \
     PERL_BITFIELD16 op_latefreed:1;    \
     PERL_BITFIELD16 op_attached:1;     \
-    PERL_BITFIELD16 op_spare:3;                \
+    PERL_BITFIELD16 op_savefree:1;     \
+    PERL_BITFIELD16 op_spare:2;                \
     U8         op_flags;               \
     U8         op_private;
 #endif

diff --git a/scope.h b/scope.h
index 74ebed9..f8df5b4 100644 (file)
--- a/scope.h
+++ b/scope.h
@@ -269,7 +269,21 @@ scope has the given name. Name must be a literal string.
 
 #define save_freesv(op)                save_pushptr((void *)(op), SAVEt_FREESV)
 #define save_mortalizesv(op)   save_pushptr((void *)(op), SAVEt_MORTALIZESV)
-#define save_freeop(op)                save_pushptr((void *)(op), SAVEt_FREEOP)
+#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
+# define save_freeop(op)                    \
+    ({                                       \
+      OP * const _o = (OP *)(op);             \
+      _o->op_savefree = 1;                     \
+      save_pushptr((void *)(_o), SAVEt_FREEOP); \
+    })
+#else
+# define save_freeop(op)                       \
+    (                                           \
+      PL_Xpv = (XPV *)(op),                      \
+      ((OP *)PL_Xpv)->op_savefree = 1,            \
+      save_pushptr((void *)(PL_Xpv), SAVEt_FREEOP) \
+    )
+#endif
 #define save_freepv(pv)                save_pushptr((void *)(pv), SAVEt_FREEPV)
 #define save_op()              save_pushptr((void *)(PL_op), SAVEt_OP)