From: divverent <divverent@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Tue, 8 Jan 2013 12:37:43 +0000 (+0000)
Subject: Breakpoints and watchpoints
X-Git-Tag: xonotic-v0.8.0~96^2~164
X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=commitdiff_plain;h=6b19a6786e080a7f70717b28951bd1d3b07d3fb0

Breakpoints and watchpoints

"Break" on statement: prvm_breakpoint server 12345
"Break" on function: prvm_breakpoint server ClientConnect
Watch for global change: prvm_globalwatchpoint server time
Watch for entity field change: prvm_edictwatchpoint server 1 health

There can be only one of each kind. To clear, do:

prvm_breakpoint server
prvm_globalwatchpoint server
prvm_edictwatchpoint server

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@11874 d7cf8633-e32d-0410-b094-e92efae38249
---

diff --git a/progsvm.h b/progsvm.h
index 5dbfd464..569f1edb 100644
--- a/progsvm.h
+++ b/progsvm.h
@@ -228,13 +228,13 @@ extern prvm_eval_t prvm_badvalue;
 #define PRVM_menufunction(funcname)           (prog->funcoffsets.funcname)
 
 #if 1
-#define PRVM_EDICTFIELDVALUE(ed, fieldoffset)    (fieldoffset < 0 ? Con_Printf("Invalid fieldoffset at %s:%i\n", __FILE__, __LINE__), &prvm_badvalue : (prvm_eval_t *)(ed->fields.fp + fieldoffset))
+#define PRVM_EDICTFIELDVALUE(ed, fieldoffset)    ((fieldoffset) < 0 ? Con_Printf("Invalid fieldoffset at %s:%i\n", __FILE__, __LINE__), &prvm_badvalue : (prvm_eval_t *)((ed)->fields.fp + (fieldoffset)))
 #define PRVM_EDICTFIELDFLOAT(ed, fieldoffset)    (PRVM_EDICTFIELDVALUE(ed, fieldoffset)->_float)
 #define PRVM_EDICTFIELDVECTOR(ed, fieldoffset)   (PRVM_EDICTFIELDVALUE(ed, fieldoffset)->vector)
 #define PRVM_EDICTFIELDSTRING(ed, fieldoffset)   (PRVM_EDICTFIELDVALUE(ed, fieldoffset)->string)
 #define PRVM_EDICTFIELDEDICT(ed, fieldoffset)    (PRVM_EDICTFIELDVALUE(ed, fieldoffset)->edict)
 #define PRVM_EDICTFIELDFUNCTION(ed, fieldoffset) (PRVM_EDICTFIELDVALUE(ed, fieldoffset)->function)
-#define PRVM_GLOBALFIELDVALUE(fieldoffset)       (fieldoffset < 0 ? Con_Printf("Invalid fieldoffset at %s:%i\n", __FILE__, __LINE__), &prvm_badvalue : (prvm_eval_t *)(prog->globals.fp + fieldoffset))
+#define PRVM_GLOBALFIELDVALUE(fieldoffset)       ((fieldoffset) < 0 ? Con_Printf("Invalid fieldoffset at %s:%i\n", __FILE__, __LINE__), &prvm_badvalue : (prvm_eval_t *)(prog->globals.fp + (fieldoffset)))
 #define PRVM_GLOBALFIELDFLOAT(fieldoffset)       (PRVM_GLOBALFIELDVALUE(fieldoffset)->_float)
 #define PRVM_GLOBALFIELDVECTOR(fieldoffset)      (PRVM_GLOBALFIELDVALUE(fieldoffset)->vector)
 #define PRVM_GLOBALFIELDSTRING(fieldoffset)      (PRVM_GLOBALFIELDVALUE(fieldoffset)->string)
@@ -591,6 +591,14 @@ typedef struct prvm_prog_s
 	int					argc;
 
 	int					trace;
+	int					break_statement;
+	int					break_stack_index;
+	int					watch_global;
+	prvm_vec_t				watch_global_value;
+	int					watch_edict;
+	int					watch_field;
+	prvm_vec_t				watch_edictfield_value;
+
 	mfunction_t			*xfunction;
 	int					xstatement;
 
@@ -763,7 +771,7 @@ void PRVM_ChildProfile_f (void);
 void PRVM_CallProfile_f (void);
 void PRVM_PrintFunction_f (void);
 
-void PRVM_PrintState(prvm_prog_t *prog);
+void PRVM_PrintState(prvm_prog_t *prog, int stack_index);
 void PRVM_Crash(prvm_prog_t *prog);
 void PRVM_ShortStackTrace(prvm_prog_t *prog, char *buf, size_t bufsize);
 const char *PRVM_AllocationOrigin(prvm_prog_t *prog);
@@ -855,12 +863,13 @@ Call InitProg with the num
 Set up the fields marked with [INIT] in the prog struct
 Load a program with LoadProgs
 */
-// Load expects to be called right after Init
+// Load expects to be called right after Reset
 void PRVM_Prog_Init(prvm_prog_t *prog);
 void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data, fs_offset_t size, int numrequiredfunc, const char **required_func, int numrequiredfields, prvm_required_field_t *required_field, int numrequiredglobals, prvm_required_field_t *required_global);
 void PRVM_Prog_Reset(prvm_prog_t *prog);
 
 void PRVM_StackTrace(prvm_prog_t *prog);
+void PRVM_Breakpoint(prvm_prog_t *prog, int stack_index, const char *text);
 
 void VM_Warning(prvm_prog_t *prog, const char *fmt, ...) DP_FUNC_PRINTF(2);
 
diff --git a/prvm_cmds.c b/prvm_cmds.c
index e7523057..ce699306 100644
--- a/prvm_cmds.c
+++ b/prvm_cmds.c
@@ -36,7 +36,7 @@ void VM_Warning(prvm_prog_t *prog, const char *fmt, ...)
 	if(prvm_backtraceforwarnings.integer && recursive != realtime) // NOTE: this compares to the time, just in case if PRVM_PrintState causes a Host_Error and keeps recursive set
 	{
 		recursive = realtime;
-		PRVM_PrintState(prog);
+		PRVM_PrintState(prog, 0);
 		recursive = -1;
 	}
 }
diff --git a/prvm_edict.c b/prvm_edict.c
index 56f3602e..41f8b2a1 100644
--- a/prvm_edict.c
+++ b/prvm_edict.c
@@ -39,6 +39,7 @@ cvar_t prvm_backtraceforwarnings = {0, "prvm_backtraceforwarnings", "0", "print
 cvar_t prvm_leaktest = {0, "prvm_leaktest", "0", "try to detect memory leaks in strings or entities"};
 cvar_t prvm_leaktest_ignore_classnames = {0, "prvm_leaktest_ignore_classnames", "", "classnames of entities to NOT leak check because they are found by find(world, classname, ...) but are actually spawned by QC code (NOT map entities)"};
 cvar_t prvm_errordump = {0, "prvm_errordump", "0", "write a savegame on crash to crash-server.dmp"};
+cvar_t prvm_breakpointdump = {0, "prvm_breakpointdump", "0", "write a savegame on breakpoint to breakpoint-server.dmp"};
 cvar_t prvm_reuseedicts_startuptime = {0, "prvm_reuseedicts_startuptime", "2", "allows immediate re-use of freed entity slots during start of new level (value in seconds)"};
 cvar_t prvm_reuseedicts_neverinsameframe = {0, "prvm_reuseedicts_neverinsameframe", "1", "never allows re-use of freed entity slots during same frame"};
 
@@ -1814,12 +1815,18 @@ static void PRVM_PO_Destroy(po_t *po)
 void PRVM_LeakTest(prvm_prog_t *prog);
 void PRVM_Prog_Reset(prvm_prog_t *prog)
 {
-	PRVM_LeakTest(prog);
-	prog->reset_cmd(prog);
-	Mem_FreePool(&prog->progs_mempool);
-	if(prog->po)
-		PRVM_PO_Destroy((po_t *) prog->po);
+	if (prog->loaded)
+	{
+		PRVM_LeakTest(prog);
+		prog->reset_cmd(prog);
+		Mem_FreePool(&prog->progs_mempool);
+		if(prog->po)
+			PRVM_PO_Destroy((po_t *) prog->po);
+	}
 	memset(prog,0,sizeof(prvm_prog_t));
+	prog->break_statement = -1;
+	prog->watch_global = -1;
+	prog->watch_edict = -1;
 }
 
 /*
@@ -1875,6 +1882,7 @@ static void PRVM_LoadLNO( prvm_prog_t *prog, const char *progname ) {
 PRVM_LoadProgs
 ===============
 */
+static void PRVM_UpdateBreakpoints(prvm_prog_t *prog);
 void PRVM_Prog_Load(prvm_prog_t *prog, const char * filename, unsigned char * data, fs_offset_t size, int numrequiredfunc, const char **required_func, int numrequiredfields, prvm_required_field_t *required_field, int numrequiredglobals, prvm_required_field_t *required_global)
 {
 	int i;
@@ -2398,6 +2406,8 @@ fail:
 
 	prog->loaded = TRUE;
 
+	PRVM_UpdateBreakpoints(prog);
+
 	// set flags & ddef_ts in prog
 
 	prog->flag = 0;
@@ -2623,6 +2633,194 @@ static void PRVM_GlobalSet_f(void)
 		PRVM_ED_ParseEpair( prog, NULL, global, Cmd_Argv(3), true );
 }
 
+/*
+======================
+Break- and Watchpoints
+======================
+*/
+typedef struct
+{
+	char break_statement[256];
+	char watch_global[256];
+	int watch_edict;
+	char watch_field[256];
+}
+debug_data_t;
+static debug_data_t debug_data[PRVM_PROG_MAX];
+
+void PRVM_Breakpoint(prvm_prog_t *prog, int stack_index, const char *text)
+{
+	char vabuf[1024];
+	Con_Printf("PRVM_Breakpoint: %s\n", text);
+	PRVM_PrintState(prog, stack_index);
+	if (prvm_breakpointdump.integer)
+		Host_Savegame_to(prog, va(vabuf, sizeof(vabuf), "breakpoint-%s.dmp", prog->name));
+}
+
+static void PRVM_UpdateBreakpoints(prvm_prog_t *prog)
+{
+	debug_data_t *debug = &debug_data[prog - prvm_prog_list];
+	if (!prog->loaded)
+		return;
+	if (debug->break_statement[0])
+	{
+		if (debug->break_statement[0] >= '0' && debug->break_statement[0] <= '9')
+		{
+			prog->break_statement = atoi(debug->break_statement);
+			prog->break_stack_index = 0;
+		}
+		else
+		{
+			mfunction_t *func;
+			func = PRVM_ED_FindFunction (prog, debug->break_statement);
+			if (!func)
+			{
+				Con_Printf("%s progs: no function or statement named %s to break on!\n", prog->name, debug->break_statement);
+				prog->break_statement = -1;
+			}
+			else
+			{
+				prog->break_statement = func->first_statement;
+				prog->break_stack_index = 1;
+			}
+		}
+		if (prog->break_statement >= -1)
+			Con_Printf("%s progs: breakpoint is at statement %d\n", prog->name, prog->break_statement);
+	}
+	else
+		prog->break_statement = -1;
+
+	if (debug->watch_global[0])
+	{
+		ddef_t *global = PRVM_ED_FindGlobal( prog, debug->watch_global );
+		if( !global )
+		{
+			Con_Printf( "%s progs: no global named '%s' to watch!\n", prog->name, debug->watch_global );
+			prog->watch_global = -1;
+		}
+		else
+		{
+			prog->watch_global = global->ofs;
+			prog->watch_global_value = PRVM_GLOBALFIELDFLOAT(prog->watch_global);
+		}
+		if (prog->watch_global >= -1)
+			Con_Printf("%s progs: global watchpoint is at global index %d\n", prog->name, prog->watch_global);
+	}
+	else
+		prog->watch_global = -1;
+
+	if (debug->watch_field[0])
+	{
+		ddef_t *field = PRVM_ED_FindField( prog, debug->watch_field );
+		if( !field )
+		{
+			Con_Printf( "%s progs: no field named '%s' to watch!\n", prog->name, debug->watch_field );
+			prog->watch_edict = -1;
+		}
+		else
+		{
+			prog->watch_edict = debug->watch_edict;
+			prog->watch_field = field->ofs;
+			if (prog->watch_edict < prog->num_edicts)
+				prog->watch_edictfield_value = PRVM_EDICTFIELDFLOAT(PRVM_EDICT_NUM(prog->watch_edict), prog->watch_field);
+			else
+				prog->watch_edictfield_value = 0;
+		}
+		if (prog->watch_edict >= -1)
+			Con_Printf("%s progs: edict field watchpoint is at edict %d field index %d\n", prog->name, prog->watch_edict, prog->watch_field);
+	}
+	else
+		prog->watch_edict = -1;
+}
+
+static void PRVM_Breakpoint_f(void)
+{
+	prvm_prog_t *prog;
+
+	if( Cmd_Argc() == 2 ) {
+		if (!(prog = PRVM_FriendlyProgFromString(Cmd_Argv(1))))
+			return;
+		{
+			debug_data_t *debug = &debug_data[prog - prvm_prog_list];
+			debug->break_statement[0] = 0;
+		}
+		PRVM_UpdateBreakpoints(prog);
+		return;
+	}
+	if( Cmd_Argc() != 3 ) {
+		Con_Printf( "prvm_breakpoint <program name> <function name | statement>\n" );
+		return;
+	}
+
+	if (!(prog = PRVM_ProgFromString(Cmd_Argv(1))))
+		return;
+
+	{
+		debug_data_t *debug = &debug_data[prog - prvm_prog_list];
+		strlcpy(debug->break_statement, Cmd_Argv(2), sizeof(debug->break_statement));
+	}
+	PRVM_UpdateBreakpoints(prog);
+}
+
+static void PRVM_GlobalWatchpoint_f(void)
+{
+	prvm_prog_t *prog;
+
+	if( Cmd_Argc() == 2 ) {
+		if (!(prog = PRVM_FriendlyProgFromString(Cmd_Argv(1))))
+			return;
+		{
+			debug_data_t *debug = &debug_data[prog - prvm_prog_list];
+			debug->watch_global[0] = 0;
+		}
+		PRVM_UpdateBreakpoints(prog);
+		return;
+	}
+	if( Cmd_Argc() != 3 ) {
+		Con_Printf( "prvm_globalwatchpoint <program name> <global name>\n" );
+		return;
+	}
+
+	if (!(prog = PRVM_ProgFromString(Cmd_Argv(1))))
+		return;
+
+	{
+		debug_data_t *debug = &debug_data[prog - prvm_prog_list];
+		strlcpy(debug->watch_global, Cmd_Argv(2), sizeof(debug->watch_global));
+	}
+	PRVM_UpdateBreakpoints(prog);
+}
+
+static void PRVM_EdictWatchpoint_f(void)
+{
+	prvm_prog_t *prog;
+
+	if( Cmd_Argc() == 2 ) {
+		if (!(prog = PRVM_FriendlyProgFromString(Cmd_Argv(1))))
+			return;
+		{
+			debug_data_t *debug = &debug_data[prog - prvm_prog_list];
+			debug->watch_field[0] = 0;
+		}
+		PRVM_UpdateBreakpoints(prog);
+		return;
+	}
+	if( Cmd_Argc() != 4 ) {
+		Con_Printf( "prvm_edictwatchpoint <program name> <edict number> <field name>\n" );
+		return;
+	}
+
+	if (!(prog = PRVM_ProgFromString(Cmd_Argv(1))))
+		return;
+
+	{
+		debug_data_t *debug = &debug_data[prog - prvm_prog_list];
+		debug->watch_edict = atoi(Cmd_Argv(2));
+		strlcpy(debug->watch_field, Cmd_Argv(3), sizeof(debug->watch_field));
+	}
+	PRVM_UpdateBreakpoints(prog);
+}
+
 /*
 ===============
 PRVM_Init
@@ -2648,6 +2846,10 @@ void PRVM_Init (void)
 	Cmd_AddCommand ("menu_cmd", PRVM_GameCommand_Menu_f, "calls the menu QC function GameCommand with the supplied string as argument");
 	Cmd_AddCommand ("sv_cmd", PRVM_GameCommand_Server_f, "calls the server QC function GameCommand with the supplied string as argument");
 
+	Cmd_AddCommand ("prvm_breakpoint", PRVM_Breakpoint_f, "marks a statement or function as breakpoint (when this is executed, a stack trace is printed); to actually halt and investigate state, combine this with a gdb breakpoint on PRVM_Breakpoint, or with prvm_breakpointdump; run with just progs name to clear breakpoint");
+	Cmd_AddCommand ("prvm_globalwatchpoint", PRVM_GlobalWatchpoint_f, "marks a global as watchpoint (when this is executed, a stack trace is printed); to actually halt and investigate state, combine this with a gdb breakpoint on PRVM_Breakpoint, or with prvm_breakpointdump; run with just progs name to clear watchpoint");
+	Cmd_AddCommand ("prvm_edictwatchpoint", PRVM_EdictWatchpoint_f, "marks an entity field as watchpoint (when this is executed, a stack trace is printed); to actually halt and investigate state, combine this with a gdb breakpoint on PRVM_Breakpoint, or with prvm_breakpointdump; run with just progs name to clear watchpoint");
+
 	Cvar_RegisterVariable (&prvm_language);
 	Cvar_RegisterVariable (&prvm_traceqc);
 	Cvar_RegisterVariable (&prvm_statementprofiling);
@@ -2656,6 +2858,7 @@ void PRVM_Init (void)
 	Cvar_RegisterVariable (&prvm_leaktest);
 	Cvar_RegisterVariable (&prvm_leaktest_ignore_classnames);
 	Cvar_RegisterVariable (&prvm_errordump);
+	Cvar_RegisterVariable (&prvm_breakpointdump);
 	Cvar_RegisterVariable (&prvm_reuseedicts_startuptime);
 	Cvar_RegisterVariable (&prvm_reuseedicts_neverinsameframe);
 
@@ -2672,10 +2875,7 @@ PRVM_InitProg
 */
 void PRVM_Prog_Init(prvm_prog_t *prog)
 {
-	if (prog->loaded)
-		PRVM_Prog_Reset(prog);
-
-	memset(prog, 0, sizeof(prvm_prog_t));
+	PRVM_Prog_Reset(prog);
 	prog->leaktest_active = prvm_leaktest.integer != 0;
 }
 
diff --git a/prvm_exec.c b/prvm_exec.c
index f2ad83ed..d1ab2436 100644
--- a/prvm_exec.c
+++ b/prvm_exec.c
@@ -480,21 +480,26 @@ void PRVM_ChildProfile_f (void)
 	PRVM_Profile(prog, howmany, 0, 1);
 }
 
-void PRVM_PrintState(prvm_prog_t *prog)
+void PRVM_PrintState(prvm_prog_t *prog, int stack_index)
 {
 	int i;
+	mfunction_t *func = prog->xfunction;
+	int st = prog->xstatement;
+	if (stack_index > 0 && stack_index <= prog->depth)
+	{
+		func = prog->stack[prog->depth - stack_index].f;
+		st = prog->stack[prog->depth - stack_index].s;
+	}
 	if (prog->statestring)
 	{
 		Con_Printf("Caller-provided information: %s\n", prog->statestring);
 	}
-	if (prog->xfunction)
+	if (func)
 	{
 		for (i = -7; i <= 0;i++)
-			if (prog->xstatement + i >= prog->xfunction->first_statement)
-				PRVM_PrintStatement(prog, prog->statements + prog->xstatement + i);
+			if (st + i >= func->first_statement)
+				PRVM_PrintStatement(prog, prog->statements + st + i);
 	}
-	else
-		Con_Print("null function executing??\n");
 	PRVM_StackTrace(prog);
 }
 
@@ -512,7 +517,7 @@ void PRVM_Crash(prvm_prog_t *prog)
 	if( prog->depth > 0 )
 	{
 		Con_Printf("QuakeC crash report for %s:\n", prog->name);
-		PRVM_PrintState(prog);
+		PRVM_PrintState(prog, 0);
 	}
 
 	if(prvm_errordump.integer)
@@ -706,7 +711,7 @@ void MVM_ExecuteProgram (prvm_prog_t *prog, func_t fnum, const char *errormessag
 
 chooseexecprogram:
 	cachedpr_trace = prog->trace;
-	if (prvm_statementprofiling.integer || prog->trace)
+	if (prvm_statementprofiling.integer || prog->trace || prog->watch_global >= 0 || prog->watch_edict >= 0 || prog->break_statement >= 0)
 	{
 #define PRVMSLOWINTERPRETER 1
 		if (prvm_timeprofiling.integer)
@@ -797,7 +802,7 @@ void CLVM_ExecuteProgram (prvm_prog_t *prog, func_t fnum, const char *errormessa
 
 chooseexecprogram:
 	cachedpr_trace = prog->trace;
-	if (prvm_statementprofiling.integer || prog->trace)
+	if (prvm_statementprofiling.integer || prog->trace || prog->watch_global >= 0 || prog->watch_edict >= 0 || prog->break_statement >= 0)
 	{
 #define PRVMSLOWINTERPRETER 1
 		if (prvm_timeprofiling.integer)
@@ -893,7 +898,7 @@ void PRVM_ExecuteProgram (prvm_prog_t *prog, func_t fnum, const char *errormessa
 
 chooseexecprogram:
 	cachedpr_trace = prog->trace;
-	if (prvm_statementprofiling.integer || prog->trace)
+	if (prvm_statementprofiling.integer || prog->trace || prog->watch_global >= 0 || prog->watch_edict >= 0 || prog->break_statement >= 0)
 	{
 #define PRVMSLOWINTERPRETER 1
 		if (prvm_timeprofiling.integer)
diff --git a/prvm_execprogram.h b/prvm_execprogram.h
index c787e6fe..314f0e9a 100644
--- a/prvm_execprogram.h
+++ b/prvm_execprogram.h
@@ -12,6 +12,32 @@
 
 // This code isn't #ifdef/#define protectable, don't try.
 
+#if PRVMSLOWINTERPRETER
+		{
+			char vabuf[1024];
+			if (prog->watch_global >= 0)
+			{
+				prvm_vec_t f = PRVM_GLOBALFIELDFLOAT(prog->watch_global);
+				if (memcmp(&f, &prog->watch_global_value, sizeof(f)))
+				{
+					prog->xstatement = st + 1 - prog->statements;
+					PRVM_Breakpoint(prog, 1, va(vabuf, sizeof(vabuf), "Global watchpoint hit by engine: " FLOAT_LOSSLESS_FORMAT " -> " FLOAT_LOSSLESS_FORMAT, prog->watch_global_value, f));
+					prog->watch_global_value = f;
+				}
+			}
+			if (prog->watch_edict >= 0 && prog->watch_edict < prog->max_edicts)
+			{
+				prvm_vec_t f = PRVM_EDICTFIELDFLOAT(prog->edicts + prog->watch_edict, prog->watch_field);
+				if (memcmp(&f, &prog->watch_edictfield_value, sizeof(f)))
+				{
+					prog->xstatement = st + 1 - prog->statements;
+					PRVM_Breakpoint(prog, 1, va(vabuf, sizeof(vabuf), "Entityfield watchpoint hit by engine: " FLOAT_LOSSLESS_FORMAT " -> " FLOAT_LOSSLESS_FORMAT, prog->watch_edictfield_value, f));
+					prog->watch_edictfield_value = f;
+				}
+			}
+		}
+#endif
+
 		while (1)
 		{
 			st++;
@@ -20,6 +46,12 @@
 			if (prog->trace)
 				PRVM_PrintStatement(prog, st);
 			prog->statement_profile[st - prog->statements]++;
+			if (prog->break_statement >= 0)
+				if ((st - prog->statements) == prog->break_statement)
+				{
+					prog->xstatement = st - prog->statements;
+					PRVM_Breakpoint(prog, prog->break_stack_index, "Breakpoint hit");
+				}
 #endif
 
 			switch (st->op)
@@ -360,6 +392,9 @@
 					}
 					else
 						prog->error_cmd("No such builtin #%i in %s; most likely cause: outdated engine build. Try updating!", builtinnumber, prog->name);
+
+					if (prog->trace != cachedpr_trace)
+						goto chooseexecprogram;
 				}
 				else
 					st = prog->statements + PRVM_EnterFunction(prog, newf);
@@ -384,8 +419,6 @@
 				startst = st;
 				if (prog->depth <= exitdepth)
 					goto cleanup; // all done
-				if (prog->trace != cachedpr_trace)
-					goto chooseexecprogram;
 				break;
 
 			case OP_STATE:
@@ -678,6 +711,31 @@
 				prog->error_cmd("Bad opcode %i in %s", st->op, prog->name);
 				goto cleanup;
 			}
+#if PRVMSLOWINTERPRETER
+			{
+				char vabuf[1024];
+				if (prog->watch_global >= 0)
+				{
+					prvm_vec_t f = PRVM_GLOBALFIELDFLOAT(prog->watch_global);
+					if (memcmp(&f, &prog->watch_global_value, sizeof(f)))
+					{
+						prog->xstatement = st - prog->statements;
+						PRVM_Breakpoint(prog, 0, va(vabuf, sizeof(vabuf), "Global watchpoint hit: " FLOAT_LOSSLESS_FORMAT " -> " FLOAT_LOSSLESS_FORMAT, prog->watch_global_value, f));
+						prog->watch_global_value = f;
+					}
+				}
+				if (prog->watch_edict >= 0 && prog->watch_edict < prog->max_edicts)
+				{
+					prvm_vec_t f = PRVM_EDICTFIELDFLOAT(prog->edicts + prog->watch_edict, prog->watch_field);
+					if (memcmp(&f, &prog->watch_edictfield_value, sizeof(f)))
+					{
+						prog->xstatement = st - prog->statements;
+						PRVM_Breakpoint(prog, 0, va(vabuf, sizeof(vabuf), "Entityfield watchpoint hit: " FLOAT_LOSSLESS_FORMAT " -> " FLOAT_LOSSLESS_FORMAT, prog->watch_edictfield_value, f));
+						prog->watch_edictfield_value = f;
+					}
+				}
+			}
+#endif
 		}
 
 #undef PreError