MARK -Ds debugging

display the MARK arity and pointers with MARK macros.
assert on markptr underflow.

5 files changed, 54 insertions, 21 deletions

diff --git a/perl.c b/perl.c
index b64975bf30..8182562cdf 100644
--- a/perl.c
+++ b/perl.c
@@ -2776,9 +2776,9 @@ Perl_call_sv(pTHX_ SV *sv, VOL I32 flags)
     }
     else {
 	myop.op_other = (OP*)&myop;
-	PL_markstack_ptr--;
+	POPMARK;
 	create_eval_scope(flags|G_FAKINGEVAL);
-	PL_markstack_ptr++;
+	INCMARK;
 
 	JMPENV_PUSH(ret);
 
diff --git a/pp.h b/pp.h
index b497085a35..5712b8eeeb 100644
--- a/pp.h
+++ b/pp.h
@@ -55,16 +55,47 @@ Refetch the stack pointer.  Used after a callback.  See L<perlcall>.
 #define MARK mark
 #define TARG targ
 
-#define PUSHMARK(p)	\
-	STMT_START {					\
-	    I32 * mark_stack_entry;			\
-	    if (UNLIKELY((mark_stack_entry = ++PL_markstack_ptr) == PL_markstack_max))	\
-	    mark_stack_entry = markstack_grow();					\
-	    *mark_stack_entry  = (I32)((p) - PL_stack_base);				\
-	} STMT_END
-
-#define TOPMARK		(*PL_markstack_ptr)
-#define POPMARK		(*PL_markstack_ptr--)
+#if defined(DEBUGGING) && defined(PERL_USE_GCC_BRACE_GROUPS)
+#define PUSHMARK(p)                                                   \
+    STMT_START {                                                      \
+        I32 * mark_stack_entry;                                       \
+        if (UNLIKELY((mark_stack_entry = ++PL_markstack_ptr) == PL_markstack_max)) \
+	    mark_stack_entry = markstack_grow();                      \
+        *mark_stack_entry  = (I32)((p) - PL_stack_base);              \
+        DEBUG_s(PerlIO_printf(Perl_debug_log, "MARK push %p %d\n",    \
+                PL_markstack_ptr, *mark_stack_entry));                \
+    } STMT_END
+#define TOPMARK                                                       \
+    ({                                                                \
+        DEBUG_s(PerlIO_printf(Perl_debug_log, "MARK top  %p %d\n",    \
+                PL_markstack_ptr, *PL_markstack_ptr));                \
+        *PL_markstack_ptr;                                            \
+    })
+#define POPMARK                                                       \
+    ({                                                                \
+        DEBUG_s(PerlIO_printf(Perl_debug_log, "MARK pop  %p %d\n",    \
+                (PL_markstack_ptr-1), *(PL_markstack_ptr-1)));        \
+        assert((PL_markstack_ptr > PL_markstack) || !"MARK underflow");\
+        *PL_markstack_ptr--;                                          \
+    })
+#define INCMARK                                                       \
+    ({                                                                \
+        DEBUG_s(PerlIO_printf(Perl_debug_log, "MARK inc  %p %d\n",    \
+                (PL_markstack_ptr+1), *(PL_markstack_ptr+1)));        \
+        *PL_markstack_ptr++;                                          \
+    })
+#else
+#define PUSHMARK(p)                                                   \
+    STMT_START {					              \
+        I32 * mark_stack_entry;                                       \
+        if (UNLIKELY((mark_stack_entry = ++PL_markstack_ptr) == PL_markstack_max)) \
+	    mark_stack_entry = markstack_grow();                      \
+        *mark_stack_entry  = (I32)((p) - PL_stack_base);              \
+    } STMT_END
+#define TOPMARK                (*PL_markstack_ptr)
+#define POPMARK                (*PL_markstack_ptr--)
+#define INCMARK                (*PL_markstack_ptr++)
+#endif
 
 #define dSP		SV **sp = PL_stack_sp
 #define djSP		dSP
@@ -506,7 +537,7 @@ Does not use C<TARG>.  See also C<L</XPUSHu>>, C<L</mPUSHu>> and C<L</PUSHu>>.
 		while (jump_o->op_type == OP_NULL)		\
 		    jump_o = jump_o->op_next;			\
 		assert(jump_o->op_type == OP_ENTERSUB);		\
-		PL_markstack_ptr--;				\
+		POPMARK;                                        \
 		return jump_o->op_next;				\
 	    }							\
 	    return NORMAL;					\
diff --git a/pp_ctl.c b/pp_ctl.c
index cdbdbd0282..f9306e1d0a 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -928,13 +928,13 @@ PP(pp_grepstart)
     dSP;
     SV *src;
 
-    if (PL_stack_base + *PL_markstack_ptr == SP) {
+    if (PL_stack_base + TOPMARK == SP) {
 	(void)POPMARK;
 	if (GIMME_V == G_SCALAR)
 	    mXPUSHi(0);
 	RETURNOP(PL_op->op_next->op_next);
     }
-    PL_stack_sp = PL_stack_base + *PL_markstack_ptr + 1;
+    PL_stack_sp = PL_stack_base + TOPMARK + 1;
     Perl_pp_pushmark(aTHX);				/* push dst */
     Perl_pp_pushmark(aTHX);				/* push src */
     ENTER_with_name("grep");					/* enter outer scope */
@@ -944,9 +944,9 @@ PP(pp_grepstart)
     ENTER_with_name("grep_item");					/* enter inner scope */
     SAVEVPTR(PL_curpm);
 
-    src = PL_stack_base[*PL_markstack_ptr];
+    src = PL_stack_base[TOPMARK];
     if (SvPADTMP(src)) {
-	src = PL_stack_base[*PL_markstack_ptr] = sv_mortalcopy(src);
+	src = PL_stack_base[TOPMARK] = sv_mortalcopy(src);
 	PL_tmps_floor++;
     }
     SvTEMP_off(src);
@@ -962,7 +962,7 @@ PP(pp_mapwhile)
 {
     dSP;
     const I32 gimme = GIMME_V;
-    I32 items = (SP - PL_stack_base) - *PL_markstack_ptr; /* how many new items */
+    I32 items = (SP - PL_stack_base) - TOPMARK; /* how many new items */
     I32 count;
     I32 shift;
     SV** src;
@@ -1063,7 +1063,7 @@ PP(pp_mapwhile)
     LEAVE_with_name("grep_item");					/* exit inner scope */
 
     /* All done yet? */
-    if (PL_markstack_ptr[-1] > *PL_markstack_ptr) {
+    if (PL_markstack_ptr[-1] > TOPMARK) {
 
 	(void)POPMARK;				/* pop top */
 	LEAVE_with_name("grep");					/* exit outer scope */
diff --git a/pp_hot.c b/pp_hot.c
index 87e306cc2f..d1e55629dc 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -3157,9 +3157,9 @@ PP(pp_grepwhile)
 	ENTER_with_name("grep_item");					/* enter inner scope */
 	SAVEVPTR(PL_curpm);
 
-	src = PL_stack_base[*PL_markstack_ptr];
+	src = PL_stack_base[TOPMARK];
 	if (SvPADTMP(src)) {
-	    src = PL_stack_base[*PL_markstack_ptr] = sv_mortalcopy(src);
+	    src = PL_stack_base[TOPMARK] = sv_mortalcopy(src);
 	    PL_tmps_floor++;
 	}
 	SvTEMP_off(src);
diff --git a/scope.c b/scope.c
index bdf299a9c4..037bbc00fd 100644
--- a/scope.c
+++ b/scope.c
@@ -131,6 +131,8 @@ Perl_markstack_grow(pTHX)
     Renew(PL_markstack, newmax, I32);
     PL_markstack_max = PL_markstack + newmax;
     PL_markstack_ptr = PL_markstack + oldmax;
+    DEBUG_s(PerlIO_printf(Perl_debug_log, "MARK grow %p %d by %d\n",
+            PL_markstack_ptr, *PL_markstack_ptr, oldmax));
     return PL_markstack_ptr;
 }