PANICTRACE (stacktrace on panic or signal) + bits

On crash signal or panic(), use a configurable method to get a stacktrace
the user can easily report to us.  Currently only for Unix/Linux and only
ifdef BETA.  Hopefully ports can add additional methods.

Bits:
- linux hints file had PREFIX definition in the wrong place
- sample sysconf file used wrong delimiter for WIZARDS
- fix grammar error in support message when using sysconf.wizards
- options.c comment typo
- capitalize "Crash test" output from #panic command

src/cmd.c

@@ -682,7 +682,7 @@ STATIC_PTR int
 wiz_panic(VOID_ARGS)
 {
 	if (yn("Do you want to call panic() and end your game?") == 'y')
-		panic("crash test.");
+		panic("Crash test.");
         return 0;
 }
 

src/decl.c

@@ -326,6 +326,10 @@ NEARDATA struct savefile_info sfrestinfo, sfsaveinfo = {
 #endif
 };
 
+#ifdef PANICTRACE
+char *ARGV0;
+#endif
+
 /* dummy routine used to force linkage */
 void
 decl_init()

src/end.c

@@ -1,5 +1,4 @@
 /* NetHack 3.5	end.c	$Date$  $Revision$ */
-/*	SCCS Id: @(#)end.c	3.5	2008/02/08	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -61,20 +60,190 @@ extern void FDECL(nethack_exit,(int));
 
 #define done_stopprint program_state.stopprint
 
+#ifndef PANICTRACE
+# define NH_abort NH_abort_
+#endif
+
 #ifdef AMIGA
-# define NH_abort()	Abort(0)
+# define NH_abort_()	Abort(0)
 #else
 # ifdef SYSV
-# define NH_abort()	(void) abort()
+# define NH_abort_()	(void) abort()
 # else
 #  ifdef WIN32
-# define NH_abort()	win32_abort()
+# define NH_abort_()	win32_abort()
 #  else
-# define NH_abort()	abort()
+# define NH_abort_()	abort()
 #  endif
 # endif
 #endif
 
+#ifdef PANICTRACE
+# include <errno.h>
+# ifdef PANICTRACE_GLIBC
+#  include <execinfo.h>
+# endif
+
+/* What do we try and in what order?  Tradeoffs:
+ * glibc: +no external programs required
+ *        -requires newish glibc
+ *        -requires -rdynamic
+ * gdb:   +gives more detailed information
+ *        +works on more OS versions
+ *        -requires -g, which may preclude -O on some compilers
+ */
+# ifdef SYSCF
+#  define SYSOPT_PANICTRACE_GDB sysopt.panictrace_gdb
+#  ifdef PANICTRACE_GLIBC
+#   define SYSOPT_PANICTRACE_GLIBC sysopt.panictrace_glibc
+#  else
+#   define SYSOPT_PANICTRACE_GLIBC 0
+#  endif
+# else
+#  define SYSOPT_PANICTRACE_GDB (nh_getenv("NETHACK_USE_GDB")==0?0:2)
+#  ifdef PANICTRACE_GLIBC
+#   define SYSOPT_PANICTRACE_GLIBC 1
+#  else
+#   define SYSOPT_PANICTRACE_GLIBC 0
+#  endif
+# endif
+
+static void NDECL(NH_abort);
+#ifndef NO_SIGNAL
+static void FDECL(panictrace_handler, (int));
+#endif
+static boolean NDECL(NH_panictrace_glibc);
+static boolean NDECL(NH_panictrace_gdb);
+
+#ifndef NO_SIGNAL
+/*ARGSUSED*/
+void
+panictrace_handler(sig_unused)   /* called as signal() handler, so sent at least one arg */
+int sig_unused;
+{
+# define SIG_MSG "\nSignal received.\n"
+	(void) write(2, SIG_MSG, sizeof(SIG_MSG)-1);
+	NH_abort();
+}
+
+void
+panictrace_setsignals(set)
+boolean set;
+{
+# define SETSIGNAL(sig) (void) signal(sig, set?(SIG_RET_TYPE)panictrace_handler:SIG_DFL);
+#  ifdef SIGILL
+	SETSIGNAL(SIGILL);
+#  endif
+#  ifdef SIGTRAP
+	SETSIGNAL(SIGTRAP);
+#  endif
+#  ifdef SIGIOT
+	SETSIGNAL(SIGIOT);
+#  endif
+#  ifdef SIGBUS
+	SETSIGNAL(SIGBUS);
+#  endif
+#  ifdef SIGFPE
+	SETSIGNAL(SIGFPE);
+#  endif
+#  ifdef SIGSEGV
+	SETSIGNAL(SIGSEGV);
+#  endif
+#  ifdef SIGSTKFLT
+	SETSIGNAL(SIGSTKFLT);
+#  endif
+#  ifdef SIGSYS
+	SETSIGNAL(SIGSYS);
+#  endif
+#  ifdef SIGEMT
+	SETSIGNAL(SIGEMT);
+#  endif
+# undef SETSIGNAL
+}
+#endif
+
+static void
+NH_abort(){
+	int gdb_prio = SYSOPT_PANICTRACE_GDB;
+	int glibc_prio = SYSOPT_PANICTRACE_GLIBC;
+	static boolean aborting = FALSE;
+
+	if(aborting) return;
+	aborting = TRUE;
+
+	if(gdb_prio == glibc_prio && gdb_prio > 0) gdb_prio++;
+
+	if(gdb_prio > glibc_prio){
+		NH_panictrace_gdb() || (glibc_prio && NH_panictrace_glibc());
+	} else {
+		NH_panictrace_glibc() || (gdb_prio && NH_panictrace_gdb());
+	}
+
+	panictrace_setsignals(FALSE);
+	NH_abort_();
+}
+
+static boolean
+NH_panictrace_glibc(){
+# ifdef PANICTRACE_GLIBC
+	void *bt[20];
+	size_t count;
+	char **info;
+	int x;
+
+	raw_print("Generating more information you may report:\n");
+	count = backtrace(bt, SIZE(bt));
+	info = backtrace_symbols(bt, count);
+	for(x=0; x<count; x++){
+		raw_printf("[%d] %s",x,info[x]);
+	}
+	/* free(info);	Don't risk it. */
+	return TRUE;
+# else
+	return FALSE;
+# endif
+}
+
+# ifdef PANICTRACE_GDB
+/* I'm going to assume /bin/grep is the right path for grep. */
+#  ifdef SYSCF
+#   define GDBPATH sysopt.gdbpath
+#  else
+#   ifndef GDBPATH
+#    define GDBPATH "/usr/bin/gdb"
+#   endif
+#  endif
+# endif
+
+static boolean
+NH_panictrace_gdb(){
+# ifdef PANICTRACE_GDB
+	/* A (more) generic method to get a stack trace - invoke
+	 * gdb on ourself. */
+	char *gdbpath = GDBPATH;
+	char buf[BUFSZ];
+
+	if(gdbpath == NULL || gdbpath[0] == 0) return FALSE;
+
+	sprintf(buf, "%s -n -q %s %d 2>&1 | /bin/grep '^#'",
+			GDBPATH, ARGV0, getpid());
+	FILE *gdb = popen(buf, "w");
+	if(gdb){
+		raw_print("Generating more information you may report:\n");
+		fprintf(gdb, "bt\nquit\ny");
+		fflush(gdb);
+		sleep(4);	/* ugly */
+		pclose(gdb);
+		return TRUE;
+	} else {
+		return FALSE;
+	}
+# else
+	return FALSE;
+# endif
+}
+#endif
+
 /*
  * The order of these needs to match the macros in hack.h.
  */
@@ -295,7 +464,7 @@ int how;
 }
 
 #if defined(WIN32) && !defined(SYSCF)
-#define NOTIFY_NETHACK_BUGS
+# define NOTIFY_NETHACK_BUGS
 #endif
 
 /*VARARGS1*/

src/files.c

@@ -2119,6 +2119,24 @@ int		src;
 		return 0;
 	    }
 	    sysopt.pointsmin = temp;
+	} else if ( (src==SET_IN_SYS) && match_varname(buf, "PANICTRACE_GLIBC", 16)) {
+	    int temp = atoi(bufp);
+	    if(temp < 1 || temp > 2){
+		raw_printf("Illegal value in PANICTRACE_GLIBC (not 0,1,2).");
+		return 0;
+	    }
+	    sysopt.panictrace_glibc = temp;
+	} else if ( (src==SET_IN_SYS) && match_varname(buf, "PANICTRACE_GDB", 14)) {
+	    int temp = atoi(bufp);
+	    if(temp < 1 || temp > 2){
+		raw_printf("Illegal value in PANICTRACE_GDB (not 0,1,2).");
+		return 0;
+	    }
+	    sysopt.panictrace_gdb = temp;
+	} else if ( (src==SET_IN_SYS) && match_varname(buf, "GDBPATH", 7)) {
+	    if(sysopt.gdbpath) free(sysopt.gdbpath);
+	    sysopt.gdbpath = (char*)alloc(strlen(bufp)+1);
+	    Strcpy(sysopt.gdbpath, bufp);
 #endif
 	} else if (match_varname(buf, "BOULDER", 3)) {
 	    (void) get_uchars(fp, buf, bufp, &iflags.bouldersym, TRUE,

src/options.c

@@ -1,5 +1,4 @@
 /* NetHack 3.5	options.c	$Date$  $Revision$ */
-/*	SCCS Id: @(#)options.c	3.5	2008/08/22	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -532,7 +531,7 @@ boolean val_allowed;
 /* most environment variables will eventually be printed in an error
  * message if they don't work, and most error message paths go through
  * BUFSZ buffers, which could be overflowed by a maliciously long
- * environment variable.  if a variable can legitimately be long, or
+ * environment variable.  If a variable can legitimately be long, or
  * if it's put in a smaller buffer, the responsible code will have to
  * bounds-check itself.
  */

src/pager.c

@@ -1,5 +1,4 @@
 /* NetHack 3.5	pager.c	$Date$  $Revision$ */
-/*	SCCS Id: @(#)pager.c	3.5	2009/01/30	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -897,7 +896,7 @@ docontact()
 		putstr(cwin, 0, "");
 	} else if(sysopt.wizards){
 		char *tmp = build_english_list(sysopt.wizards);
-		Sprintf(buf, "To contact local support, %s", tmp);
+		Sprintf(buf, "To contact local support, contact %s.", tmp);
 		free(tmp);
 		putstr(cwin, 0, buf);
 		putstr(cwin, 0, "");

src/sys.c

@@ -24,11 +24,27 @@ sys_early_init(){
 	sysopt.pointsmin = POINTSMIN;
 	sysopt.pers_is_uid = PERS_IS_UID;
 
-			/* sanity checks */
+		/* sanity checks */
 	if(PERSMAX<1) sysopt.persmax = 1;
 	if(ENTRYMAX<10) sysopt.entrymax = 10;
 	if(POINTSMIN<1) sysopt.pointsmin = 1;
 	if(PERS_IS_UID != 0 && PERS_IS_UID != 1)
 		panic("config error: PERS_IS_UID must be either 0 or 1");
+
+#ifdef PANICTRACE
+		/* panic options */
+	sysopt.gdbpath = NULL;
+# ifdef BETA
+	sysopt.panictrace_gdb = 1;
+#  ifdef PANICTRACE_GLIBC
+	sysopt.panictrace_glibc = 2;
+#  endif
+# else
+	sysopt.panictrace_gdb = 0;
+#  ifdef PANICTRACE_GLIBC
+	sysopt.panictrace_glibc = 0;
+#  endif
+# endif
+#endif
 }