monitor: fix bug 2177

If we are leaving the monitor with a change in program flow, and there is a breakpoint on the new address, take the breakpoint right away instead of leaving the monitor.
The monitor command "G XXXX" is considered a change in flow.
This is because of the structure of the DO_INTERRUPT() macro, which can enter the monitor under different conditions in different places, but each only once per executed instruction.


git-svn-id: https://svn.code.sf.net/p/vice-emu/code/trunk@45822 379a1393-f5fb-40a0-bcee-ef074d9b53f7

Author: Rhialto

vice/src/monitor/mon_breakpoint.c

@@ -689,7 +689,7 @@ int breakpoint_add_checkpoint(MON_ADDR start_addr, MON_ADDR end_addr,
     update_checkpoint_state(mem);
 
     if (is_temp) {
-        exit_mon = 1;
+        exit_mon = exit_mon_continue;
     }
 
     if (do_print) {

vice/src/monitor/mon_file.c

@@ -506,7 +506,7 @@ int mon_autostart(const char *image_name,
 
     /* leave monitor but return after autostart */
     autostart_trigger_monitor(1);
-    exit_mon = 1;
+    exit_mon = exit_mon_continue;
 
     return result;
 }

vice/src/monitor/monitor.c

@@ -163,7 +163,7 @@ typedef struct symbol_table symbol_table_t;
 extern void set_yydebug(int debug);
 
 static char *last_cmd = NULL;
-int exit_mon = 0;
+enum exit_mon exit_mon = exit_mon_no;
 /* flag used by the single-stepping commands to prevent switching forth and back
  * to the emulator window when stepping a single instruction. note that this is
  * different from what keep_monitor_open does :)
@@ -986,18 +986,18 @@ void mon_set_mem_val_ex(MEMSPACE mem, int bank, uint16_t mem_addr, uint8_t val)
     }
 }
 
-/* exit monitor  */
+/* exit monitor, G XXXX  */
 void mon_jump(MON_ADDR addr)
 {
     mon_evaluate_default_addr(&addr);
     (monitor_cpu_for_memspace[addr_memspace(addr)]->mon_register_set_val)(addr_memspace(addr), e_PC, (uint16_t)(addr_location(addr)));
-    exit_mon = 1;
+    exit_mon = exit_mon_change_flow;
 }
 
-/* exit monitor  */
+/* exit monitor, G (not G XXXX)  */
 void mon_go(void)
 {
-    exit_mon = 1;
+    exit_mon = exit_mon_continue;
     mon_console_suspend_on_leaving = 0;
 
     if (should_pause_on_exit_mon || ui_pause_active()) {
@@ -1009,7 +1009,7 @@ void mon_go(void)
 /* exit monitor, close monitor window  */
 void mon_exit(void)
 {
-    exit_mon = 1;
+    exit_mon = exit_mon_continue;
     mon_console_close_on_leaving = 1;
 
     if (should_pause_on_exit_mon || ui_pause_active()) {
@@ -1026,7 +1026,7 @@ void mon_exit(void)
 */
 void mon_quit(void)
 {
-    exit_mon = 2;
+    exit_mon = exit_mon_quit_vice;
 }
 
 void mon_keyboard_feed(const char *string)
@@ -1337,7 +1337,7 @@ void mon_reset_machine(int type)
     switch (type) {
         case 1:
             machine_trigger_reset(MACHINE_RESET_MODE_POWER_CYCLE);
-            exit_mon = 1;
+            exit_mon = exit_mon_continue;
             break;
         case 8:
         case 9:
@@ -1347,7 +1347,7 @@ void mon_reset_machine(int type)
             break;
         default:
             machine_trigger_reset(MACHINE_RESET_MODE_RESET_CPU);
-            exit_mon = 1;
+            exit_mon = exit_mon_continue;
             break;
     }
 }
@@ -1642,7 +1642,7 @@ void monitor_init(monitor_interface_t *maincpu_interface_init,
     } else if (init_break_mode == ON_RESET) {
         mon_breakpoint_add_checkpoint((uint16_t)0, (uint16_t)0xffff,
                 true, e_exec, true, false);
-        exit_mon = 0;
+        exit_mon = exit_mon_no;
 #endif
     }
 }
@@ -2566,7 +2566,7 @@ void mon_instructions_step(int count)
     instruction_count = (count >= 0) ? count : 1;
     wait_for_return_level = 0;
     skip_jsrs = false;
-    exit_mon = 1;
+    exit_mon = exit_mon_continue;
 
     mon_console_suspend_on_leaving = 0;
 
@@ -2585,7 +2585,7 @@ void mon_instructions_next(int count)
     }
     wait_for_return_level = (int)((MONITOR_GET_OPCODE(default_memspace) == OP_JSR) ? 1 : 0);
     skip_jsrs = true;
-    exit_mon = 1;
+    exit_mon = exit_mon_continue;
 
     mon_console_suspend_on_leaving = 0;
 
@@ -2602,7 +2602,7 @@ void mon_instruction_return(void)
              || MONITOR_GET_OPCODE(default_memspace) == OP_RTI) ?
             0 : (MONITOR_GET_OPCODE(default_memspace) == OP_JSR) ? 2 : 1);
     skip_jsrs = true;
-    exit_mon = 1;
+    exit_mon = exit_mon_continue;
 
     monitor_mask[default_memspace] |= MI_STEP;
     interrupt_monitor_trap_on(mon_interfaces[default_memspace]->int_status);
@@ -3073,7 +3073,7 @@ static void monitor_open(void)
 
     if (console_log == NULL) {
         log_error(LOG_DEFAULT, "monitor_open: could not open monitor console.");
-        exit_mon = 1;
+        exit_mon = exit_mon_continue;
         return;
     }
 
@@ -3199,7 +3199,7 @@ static void monitor_open(void)
 #endif
 }
 
-static int monitor_process(char *cmd)
+static void monitor_process(char *cmd)
 {
     char *trimmed_command;
 
@@ -3240,16 +3240,14 @@ static int monitor_process(char *cmd)
     lib_free(last_cmd);
 
     /* remember last command, except when leaving the monitor */
-    if (exit_mon && mon_console_suspend_on_leaving) {
+    if (exit_mon != exit_mon_no && mon_console_suspend_on_leaving) {
         lib_free(cmd);
         last_cmd = NULL;
     } else {
         last_cmd = cmd;
     }
 
     uimon_notify_change();
-
-    return exit_mon;
 }
 
 static void monitor_close(bool check_exit)
@@ -3259,18 +3257,14 @@ static void monitor_close(bool check_exit)
 #endif
     inside_monitor = false;
 
-    if (exit_mon) {
-        exit_mon--;
-    }
-
-    if (check_exit && exit_mon) {
+    if (check_exit && exit_mon == exit_mon_quit_vice) {
         if (!monitor_is_remote()) {
             uimon_window_close();
         }
         archdep_vice_exit(0);
     }
 
-    exit_mon = 0;
+    exit_mon = exit_mon_no;
 
     if (!monitor_is_remote() && !monitor_is_binary()) {
         if (mon_console_suspend_on_leaving) {
@@ -3299,6 +3293,19 @@ static void monitor_close(bool check_exit)
     vsync_suspend_speed_eval();
 }
 
+static int check_for_breakpoint(MEMSPACE mem)
+{
+    int reg_pc;
+
+    if (mem == e_default_space) {
+        mem = default_memspace;
+    }
+
+    reg_pc = (monitor_cpu_for_memspace[mem]->mon_register_get_val)(mem, e_PC);
+
+    return monitor_check_breakpoints(mem, (uint16_t)reg_pc);
+}
+
 void monitor_startup(MEMSPACE mem)
 {
     char prompt[40];
@@ -3326,7 +3333,7 @@ void monitor_startup(MEMSPACE mem)
     }
 
     monitor_open();
-    while (!exit_mon) {
+    for (;;) {
 
         if (playback_fp) {
             playback_next_command();
@@ -3343,13 +3350,23 @@ void monitor_startup(MEMSPACE mem)
             make_prompt(prompt);
             p = uimon_in(prompt);
             if (p) {
-                exit_mon = monitor_process(p);
-            } else if (exit_mon < 1) {
+                monitor_process(p);
+            } else if (exit_mon == exit_mon_no) {
                 mon_exit();
             }
         }
 
-        if (exit_mon) {
+        if (exit_mon == exit_mon_change_flow) {
+            /*
+             * If we are about to exit the monitor with a change of program flow,
+             * check if we land on a breakpoint and if so, do not exit.
+             */
+            if (check_for_breakpoint(mem)) {
+                exit_mon = exit_mon_no;
+            }
+        }
+
+        if (exit_mon != exit_mon_no) {
             /* mon_out("exit\n"); */
             break;
         }

vice/src/monitor/monitor_binary.c

@@ -1028,7 +1028,7 @@ static void monitor_binary_process_resource_set(binary_command_t *command)
 
 static void monitor_binary_process_exit(binary_command_t *command)
 {
-    exit_mon = 1;
+    exit_mon = exit_mon_continue;
 
     monitor_binary_response(0, e_MON_RESPONSE_EXIT, e_MON_ERR_OK, command->request_id, NULL);
 }
@@ -1955,7 +1955,7 @@ int monitor_binary_get_command_line(void)
 
         monitor_binary_process_command(buffer);
 
-        if (exit_mon) {
+        if (exit_mon != exit_mon_no) {
             return 0;
         }
     }

vice/src/monitor/montypes.h

@@ -237,7 +237,15 @@ struct monitor_cpu_type_s;
 extern struct console_s *console_log;
 extern int sidefx;
 extern int break_on_dummy_access;
-extern int exit_mon;
+
+enum exit_mon {
+    exit_mon_no = 0,            /* Do not exit the monitor */
+    exit_mon_continue = 1,      /* Exit and continue normal program flow */
+    exit_mon_change_flow = 2,   /* Exit with changed program flow */
+    exit_mon_quit_vice = 3      /* Exit monitor and even the whole VICE */
+};
+
+extern enum exit_mon exit_mon;
 
 extern RADIXTYPE default_radix;
 extern MEMSPACE default_memspace;