From 524d4a27e4e5a27ea10c9486e775789a6aa65e4d Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Wed, 6 Feb 2019 22:53:44 -0500
Subject: [PATCH] halt_printf, control-c, etc set a halt bit.  This now invokes
 the debugger, asynchronously (ie, after the current instruction finishes
 execution).

---
 src/debug_shell.re2c |  6 ++++++
 src/defcomm.h        |  3 +--
 src/engine_c.c       |  3 ++-
 src/sim65816.c       | 25 +++++++++++--------------
 4 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/src/debug_shell.re2c b/src/debug_shell.re2c
index 5ecf337..472607a 100644
--- a/src/debug_shell.re2c
+++ b/src/debug_shell.re2c
@@ -876,6 +876,12 @@ int debug_shell(int code) {
 		} 
 		printf("%06x: %0*x\n", g_abort_address, g_abort_bytes * 2, g_abort_value);
 	}
+	if (code == RET_BRK) {
+		/* hit a BRK op */
+	}
+	if (code == RET_HALT) {
+		/* halt_printf */
+	}
 
 	do_list(engine.kpc, &psr, 1);
 
diff --git a/src/defcomm.h b/src/defcomm.h
index ae86aef..aaca6c0 100644
--- a/src/defcomm.h
+++ b/src/defcomm.h
@@ -88,8 +88,7 @@
 #define RET_MVN		0x5
 #define RET_WAI		0x6
 #define RET_STP		0x7
-#define RET_ADD_DEC_8	0x8
-#define RET_ADD_DEC_16	0x9
+#define RET_HALT	0x8
 #define RET_C700	0xa
 #define RET_C70A	0xb
 #define RET_C70D	0xc
diff --git a/src/engine_c.c b/src/engine_c.c
index 511e7f1..a4cf77c 100644
--- a/src/engine_c.c
+++ b/src/engine_c.c
@@ -880,7 +880,8 @@ word32 get_itimer()        {
 }
 
 void set_halt_act(int val)      {
-  if(val == 1 && g_ignore_halts && !g_user_halt_bad) {
+  extern int g_dbg_shell;
+  if(val == 1 && g_ignore_halts && !g_user_halt_bad && !g_dbg_shell) {
     g_code_red++;
   } else {
     halt_sim |= val;
diff --git a/src/sim65816.c b/src/sim65816.c
index 1e83171..7cc7ddf 100644
--- a/src/sim65816.c
+++ b/src/sim65816.c
@@ -1514,11 +1514,11 @@ int run_prog()      {
       ret >>= 28;
     }
 
-    if(halt_sim == HALT_EVENT) {
+    if(halt_sim & HALT_EVENT) {
       g_engine_halt_event++;
       /* if we needed to stop to check for interrupts, */
       /*  clear halt */
-      halt_sim = 0;
+      halt_sim &= ~HALT_EVENT;
     }
 
 #if 0
@@ -1535,7 +1535,7 @@ int run_prog()      {
 
     this_event = g_event_start.next;
     while(dcycs >= this_event->dcycs) {
-      if(halt_sim != 0 && halt_sim != HALT_EVENT) {
+      if(halt_sim & ~HALT_EVENT) {
         break;
       }
       if(g_stepping) {
@@ -1605,9 +1605,7 @@ int run_prog()      {
     }
 #endif
 
-    if(halt_sim != 0 && halt_sim != HALT_EVENT) {
-      break;
-    }
+
     if (ret == RET_MP) break;
     if (ret == RET_BP) break;
     engine.flags &= ~(FLAG_IGNORE_BP | FLAG_IGNORE_MP);
@@ -1615,6 +1613,12 @@ int run_prog()      {
       ret = 0;
       break;
     }
+    if(halt_sim & 0x07) {
+      halt_sim &= ~0x07;
+      ret = RET_HALT;
+      break;
+    }
+
   }
 
 #if 0
@@ -2256,14 +2260,6 @@ void handle_action(word32 ret)      {
     case RET_C70D:
       do_c70d(ret);
       break;
-#if 0
-    case RET_ADD_DEC_8:
-      do_add_dec_8(ret);
-      break;
-    case RET_ADD_DEC_16:
-      do_add_dec_16(ret);
-      break;
-#endif
     case RET_IRQ:
       irq_printf("Special fast IRQ response.  irq_pending: %x\n",
                  g_irq_pending);
@@ -2277,6 +2273,7 @@ void handle_action(word32 ret)      {
     case RET_BP:
     case RET_MP:
     case RET_BRK:
+    case RET_HALT:
       /* handled elsewhere */
       break;
     default: