add some debugging BREADCRUMBS to identify caller of some functions

Only takes effect if a developer uncomments BREADCRUMBS in config.h

doc/fixes36.3

@@ -1,4 +1,4 @@
-$NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.31 $ $NHDT-Date: 1559422205 2019/06/01 20:50:05 $
+$NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.33 $ $NHDT-Date: 1559601004 2019/06/03 22:30:04 $
 
 This fixes36.3 file is here to capture information about updates in the 3.6.x
 lineage following the release of 3.6.2 in May 2019. Please note, however,
@@ -91,4 +91,6 @@ add a couple of engraving suggestions in pull request #79
 
 Code Cleanup and Reorganization
 -------------------------------
+began to add some function caller BREADCRUMBS to aid debugging
+
 

include/config.h

@@ -1,4 +1,4 @@
-/* NetHack 3.6	config.h	$NHDT-Date: 1558248715 2019/05/19 06:51:55 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.122 $ */
+/* NetHack 3.6	config.h	$NHDT-Date: 1559601008 2019/06/03 22:30:08 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.123 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2016. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -526,6 +526,12 @@ typedef unsigned char uchar;
  * probably not useful for normal play */
 /* #define EXTRA_SANITY_CHECKS */
 
+/* BREADCRUMBS employs the use of predefined compiler macros
+ * __FUNCTION__ and __LINE__ to store some caller breadcrumbs
+ * for use during heavy debugging sessions. Only define if your
+ * compiler supports those predefined macros and you are debugging */
+/* #define BREADCRUMBS */
+
 /* EDIT_GETLIN makes the string input in TTY, curses, Qt4, and X11
    for some prompts be pre-loaded with previously input text (from
    a previous instance of the same prompt) as the default response.

include/decl.h

@@ -1,4 +1,4 @@
-/* NetHack 3.6  decl.h  $NHDT-Date: 1547025154 2019/01/09 09:12:34 $  $NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.147 $ */
+/* NetHack 3.6  decl.h  $NHDT-Date: 1559601011 2019/06/03 22:30:11 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.150 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2007. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -431,6 +431,12 @@ struct plinemsg_type {
 
 E struct plinemsg_type *plinemsg_types;
 
+struct breadcrumbs {
+    const char *funcnm;
+    int linenum;
+    boolean in_effect;
+};
+
 #ifdef PANICTRACE
 E const char *ARGV0;
 #endif

include/extern.h

@@ -1,4 +1,4 @@
-/* NetHack 3.6	extern.h	$NHDT-Date: 1559422206 2019/06/01 20:50:06 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.707 $ */
+/* NetHack 3.6	extern.h	$NHDT-Date: 1559601014 2019/06/03 22:30:14 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.708 $ */
 /* Copyright (c) Steve Creps, 1988.				  */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -127,8 +127,15 @@ E void FDECL(uchangealign, (int, int));
 
 E void FDECL(ballrelease, (BOOLEAN_P));
 E void NDECL(ballfall);
+#ifndef BREADCRUMBS
 E void NDECL(placebc);
 E void NDECL(unplacebc);
+#else
+E void FDECL(Placebc, (const char *, int));
+E void FDECL(Unplacebc, (const char *, int));
+#define placebc() Placebc(__FUNCTION__, __LINE__)
+#define unplacebc() Unplacebc(__FUNCTION__, __LINE__)
+#endif
 E void FDECL(set_bc, (int));
 E void FDECL(move_bc, (int, int, XCHAR_P, XCHAR_P, XCHAR_P, XCHAR_P));
 E boolean FDECL(drag_ball, (XCHAR_P, XCHAR_P, int *, xchar *, xchar *,

src/ball.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	ball.c	$NHDT-Date: 1559554598 2019/06/03 09:36:38 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.39 $ */
+/* NetHack 3.6	ball.c	$NHDT-Date: 1559601027 2019/06/03 22:30:27 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.40 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) David Cohrs, 2006. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -10,6 +10,13 @@
 
 STATIC_DCL int NDECL(bc_order);
 STATIC_DCL void NDECL(litter);
+STATIC_OVL void NDECL(placebc_core);
+STATIC_OVL void NDECL(unplacebc_core);
+
+#ifdef BREADCRUMBS
+static struct breadcrumbs bcpbreadcrumbs = { (const char *) 0, 0, FALSE},
+                          bcubreadcrumbs = { (const char *) 0, 0, FALSE};
+#endif
 
 void
 ballrelease(showmsg)
@@ -106,8 +113,8 @@ ballfall()
  *
  *  Should not be called while swallowed except on waterlevel.
  */
-void
+STATIC_OVL void
-placebc()
+placebc_core()
 {
     if (!uchain || !uball) {
         impossible("Where are your ball and chain?");
@@ -132,8 +139,34 @@ placebc()
     newsym(u.ux, u.uy);
 }
 
+#ifdef BREADCRUMBS
 void
-unplacebc()
+Placebc(funcnm, linenum)
+const char *funcnm;
+int linenum;
+{
+    if (uball && bcpbreadcrumbs.in_effect && uball->where == OBJ_FLOOR) {
+        impossible("placebc collision from %s:%d, already placed by %s:%d",
+                   funcnm, linenum,
+                   bcpbreadcrumbs.funcnm, bcpbreadcrumbs.linenum);
+        return;
+    }
+    bcpbreadcrumbs.in_effect = TRUE;
+    bcubreadcrumbs.in_effect = FALSE;
+    bcpbreadcrumbs.funcnm = funcnm;
+    bcpbreadcrumbs.linenum = linenum;
+    placebc_core();
+}
+#else
+void
+placebc()
+{
+    placebc_core();
+}
+#endif
+
+STATIC_OVL void
+unplacebc_core()
 {
     if (u.uswallow) {
         if (Is_waterlevel(&u.uz)) {
@@ -164,6 +197,34 @@ unplacebc()
     u.bc_felt = 0; /* feel nothing */
 }
 
+#ifdef BREADCRUMBS
+void
+Unplacebc(funcnm, linenum)
+const char *funcnm;
+int linenum;
+{
+#if 0
+    if (uball && bcubreadcrumbs.in_effect && uball->where == OBJ_FREE) {
+        impossible("placebc collision from %s:%d, already placed by %s:%d",
+                   funcnm, linenum,
+                   bcpbreadcrumbs.funcnm, bcpbreadcrumbs.linenum);
+        return;
+    }
+#endif
+    bcpbreadcrumbs.in_effect = FALSE;
+    bcubreadcrumbs.in_effect = TRUE;
+    bcubreadcrumbs.funcnm = funcnm;
+    bcubreadcrumbs.linenum = linenum;
+    unplacebc_core();
+}
+#else
+void
+unplacebc()
+{
+    unplacebc_core();
+}
+#endif
+
 /*
  *  Return the stacking of the hero's ball & chain.  This assumes that the
  *  hero is being punished.