A somewhat more robust handling of debugging frames

[perl/modules/Scope-Upper.git] / Upper.xs

diff --git a/Upper.xs b/Upper.xs
index 4ee44e55770b5ce07bd5f68c30b1760b3e29843a..42f457e4302a5f46294c457612e79477aafb1634 100644 (file)
--- a/Upper.xs
+++ b/Upper.xs
@@ -44,16 +44,12 @@
 # define SvPV_nolen_const(S) SvPV_nolen(S)
 #endif
 
-#ifndef HvNAME_get
-# define HvNAME_get(H) HvNAME(H)
-#endif
-
-#ifndef ENTER_with_name
-# define ENTER_with_name(N) ENTER
+#ifndef SvREFCNT_inc_simple_void
+# define SvREFCNT_inc_simple_void(sv) SvREFCNT_inc(sv)
 #endif
 
-#ifndef LEAVE_with_name
-# define LEAVE_with_name(N) LEAVE
+#ifndef HvNAME_get
+# define HvNAME_get(H) HvNAME(H)
 #endif
 
 #ifndef gv_fetchpvn_flags
@@ -184,7 +180,7 @@ STATIC void su_save_adelete(pTHX_ AV *av, I32 idx) {
  Newx(ud, 1, su_ud_adelete);
  ud->av  = av;
  ud->idx = idx;
- SvREFCNT_inc(av);
+ SvREFCNT_inc_simple_void(av);
 
  SAVEDESTRUCTOR_X(su_adelete, ud);
 }
@@ -360,7 +356,7 @@ STATIC void su_ud_localize_init(pTHX_ su_ud_localize *ud, SV *sv, SV *val, SV *e
  UV deref = 0;
  svtype t = SVt_NULL;
 
- SvREFCNT_inc(sv);
+ SvREFCNT_inc_simple_void(sv);
 
  if (SvTYPE(sv) >= SVt_PVGV) {
   if (!val || !SvROK(val)) { /* local *x; or local *x = $val; */
@@ -405,6 +401,7 @@ STATIC void su_ud_localize_init(pTHX_ su_ud_localize *ud, SV *sv, SV *val, SV *e
   case SVt_PVCV:
   case SVt_PVGV:
    deref = 0;
+  default:
    break;
  }
  /* When deref is set, val isn't NULL */
@@ -525,11 +522,30 @@ STATIC void su_pop(pTHX_ void *ud) {
  SU_UD_DEPTH(ud) = --depth;
 
  if (depth > 0) {
-  SU_D(PerlIO_printf(Perl_debug_log,
-          "%p: set new destructor at depth=%2d scope_ix=%2d save_ix=%2d\n",
-           ud,                       depth, PL_scopestack_ix, PL_savestack_ix));
+  I32 i = 1;
 
   SAVEDESTRUCTOR_X(su_pop, ud);
+
+  /* Skip depths corresponding to scopes for which leave_scope() might not be
+   * called. */
+  while (depth > 1 && PL_scopestack_ix >= i) {
+   I32 j = PL_scopestack[PL_scopestack_ix - i];
+
+   if (j < PL_savestack_ix)
+    break;
+
+   SU_D(PerlIO_printf(Perl_debug_log,
+    "%p: skip scope%*cat depth=%2d scope_ix=%2d new_top=%2d >= cur_base=%2d\n",
+     ud,           6, ' ',   depth, PL_scopestack_ix - i, j, PL_savestack_ix));
+
+   SU_UD_DEPTH(ud) = --depth;
+
+   ++i;
+  }
+
+  SU_D(PerlIO_printf(Perl_debug_log,
+         "%p: set destructor  at depth=%2d scope_ix=%2d save_ix=%2d\n",
+          ud,                        depth, PL_scopestack_ix, PL_savestack_ix));
  } else {
   SU_UD_HANDLER(ud)(aTHX_ ud);
  }
@@ -539,18 +555,25 @@ STATIC void su_pop(pTHX_ void *ud) {
                      ud, PL_savestack_ix, PL_scopestack[PL_scopestack_ix]));
 }
 
+/* --- Global data --------------------------------------------------------- */
+
+#define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
+
+typedef struct {
+ int stack_placeholder;
+ I32 cxix;
+ I32 items;
+ SV  **savesp;
+ OP  fakeop;
+} my_cxt_t;
+
+START_MY_CXT
+
 /* --- Initialize the stack and the action userdata ------------------------ */
 
 STATIC I32 su_init(pTHX_ I32 cxix, void *ud, I32 size) {
 #define su_init(L, U, S) su_init(aTHX_ (L), (U), (S))
- I32 i, depth = 0, *origin;
-
- LEAVE_with_name("sub");
-
- if (cxix >= cxstack_ix) {
-  SU_UD_HANDLER(ud)(aTHX_ ud);
-  goto done;
- }
+ I32 i, depth = 1, *origin;
 
  SU_D(PerlIO_printf(Perl_debug_log, "%p: ### init for cx %d\n", ud, cxix));
 
@@ -606,6 +629,15 @@ STATIC I32 su_init(pTHX_ I32 cxix, void *ud, I32 size) {
         "%p: set original destructor at depth=%2d scope_ix=%2d save_ix=%2d\n",
          ud,                     depth, PL_scopestack_ix - 1, PL_savestack_ix));
 
+ /* Make sure the first destructor fires by pushing enough fake slots on the
+  * stack. */
+ if (PL_savestack_ix + 3 <= PL_scopestack[PL_scopestack_ix - 1]) {
+  dMY_CXT;
+  do {
+   save_int(&MY_CXT.stack_placeholder);
+  } while (PL_savestack_ix + 3 <= PL_scopestack[PL_scopestack_ix - 1]);
+ }
+
  SAVEDESTRUCTOR_X(su_pop, ud);
 
  SU_D({
@@ -618,25 +650,9 @@ STATIC I32 su_init(pTHX_ I32 cxix, void *ud, I32 size) {
   }
  });
 
-done:
- ENTER_with_name("sub");
-
  return depth;
 }
 
-/* --- Global data --------------------------------------------------------- */
-
-#define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
-
-typedef struct {
- I32 cxix;
- I32 items;
- SV  **savesp;
- OP  fakeop;
-} my_cxt_t;
-
-START_MY_CXT
-
 /* --- Unwind stack -------------------------------------------------------- */
 
 STATIC void su_unwind(pTHX_ void *ud_) {
@@ -690,18 +706,21 @@ STATIC void su_unwind(pTHX_ void *ud_) {
 
 #define SU_SKIP_DB(C) \
  STMT_START {         \
-  I32 i = 1;          \
-  PERL_CONTEXT *cx = cxstack + (C); \
-  do {                              \
-   if (CxTYPE(cx) == CXt_BLOCK && (C) >= i) { \
-    --cx;                                     \
-    if (CxTYPE(cx) == CXt_SUB && cx->blk_sub.cv == GvCV(PL_DBsub)) { \
-     (C) -= i + 1;                 \
-     break;                        \
-    }                              \
-   } else                          \
-    break;                         \
-  } while (++i <= SU_SKIP_DB_MAX); \
+  I32 skipped = 0;    \
+  PERL_CONTEXT *base = cxstack;      \
+  PERL_CONTEXT *cx   = base + (C);   \
+  while (cx >= base && (C) > skipped && CxTYPE(cx) == CXt_BLOCK) \
+   --cx, ++skipped;                  \
+  if (cx >= base && (C) > skipped) { \
+   switch (CxTYPE(cx)) {  \
+    case CXt_SUB:         \
+     if (skipped <= SU_SKIP_DB_MAX && cx->blk_sub.cv == GvCV(PL_DBsub)) \
+      (C) -= skipped + 1; \
+      break;              \
+    default:              \
+     break;               \
+   }                      \
+  }                       \
  } STMT_END
 
 #define SU_GET_CONTEXT(A, B)   \
@@ -786,10 +805,14 @@ PROTOTYPES: ENABLE
 BOOT:
 {
  HV *stash;
+
  MY_CXT_INIT;
+ MY_CXT.stack_placeholder = 0;
+
  stash = gv_stashpv(__PACKAGE__, 1);
  newCONSTSUB(stash, "TOP",           newSViv(0));
  newCONSTSUB(stash, "SU_THREADSAFE", newSVuv(SU_THREADSAFE));
+
  newXSproto("Scope::Upper::unwind", XS_Scope__Upper_unwind, file, NULL);
 }