[m-rev.] diff: debugging the declarative debugger

[Mark Anthony BROWN]

Hi,

This change will allow me to debug another change I am working on.

Cheers,
Mark.

Estimated hours taken: 2
Branches: main

Improve meta-debugging of the declarative debugger.  Add a declarative
debugging mode which leaves MR_trace_enabled equal to TRUE when the
front end is called, so that it generates trace events.  This mode is
used by invoking the mdb command 'dd_dd' with no parameters.  This is a
developer-only command.

Rearrange code to reduce duplication.

trace/mercury_trace_declarative.h:
trace/mercury_trace_declarative.c:
	- Handle all debugging modes via MR_decl_diagnosis (subsuming
	  the functionality of MR_decl_diagnosis_test).
	- Add an argument for the trace mode to MR_trace_start_decl_debug,
	  and use this information to determine its behaviour.
	- Add a missing fflush of MR_mdb_out.

trace/mercury_trace_internal.c:
	- Implement the new version of dd_dd.
	- Move the code for checking the current port into
	  MR_trace_start_decl_debug.

trace/mercury_trace_internal.h:
	- Add the new mode to MR_Trace_Mode.
	- Rename MR_TRACE_DECL_DEBUG_TEST to MR_TRACE_DECL_DEBUG_DUMP,
	  since there are now two modes for testing.

Index: trace/mercury_trace_declarative.c
===================================================================
RCS file: /home/mercury1/repository/mercury/trace/mercury_trace_declarative.c,v
retrieving revision 1.42
diff -u -r1.42 mercury_trace_declarative.c
--- trace/mercury_trace_declarative.c	2001/03/18 23:10:16	1.42
+++ trace/mercury_trace_declarative.c	2001/04/26 17:38:59
@@ -255,9 +255,6 @@
 MR_decl_diagnosis(MR_Trace_Node root, MR_Trace_Cmd_Info *cmd,
 		MR_Event_Info *event_info, MR_Event_Details *event_details);
 
-static	void
-MR_decl_diagnosis_test(MR_Trace_Node root);
-
 static	MR_Code *
 MR_decl_handle_bug_found(MR_Unsigned event, MR_Trace_Cmd_Info *cmd,
 		MR_Event_Info *event_info, MR_Event_Details *event_details);
@@ -448,22 +445,8 @@
 		/*
 		** Call the front end.
 		*/
-		switch (MR_trace_decl_mode) {
-			case MR_TRACE_DECL_DEBUG:
-				return MR_decl_diagnosis(
-						MR_trace_current_node, cmd,
-						event_info, &event_details);
-
-			case MR_TRACE_DECL_DEBUG_TEST:
-				MR_decl_diagnosis_test(MR_trace_current_node);
-				break;
-
-			default:
-				MR_fatal_error("MR_trace_decl_debug: "
-						"unexpected mode");
-		}
-		MR_trace_decl_mode = MR_TRACE_INTERACTIVE;
-		return MR_trace_event_internal(cmd, TRUE, event_info);
+		return MR_decl_diagnosis(MR_trace_current_node, cmd,
+					event_info, &event_details);
 	}
 
 	MR_trace_enabled = TRUE;
@@ -1163,9 +1146,9 @@
 }
 
 bool
-MR_trace_start_decl_debug(const char *outfile, MR_Trace_Cmd_Info *cmd,
-		MR_Event_Info *event_info, MR_Event_Details *event_details,
-		MR_Code **jumpaddr)
+MR_trace_start_decl_debug(MR_Trace_Mode trace_mode, const char *outfile,
+		MR_Trace_Cmd_Info *cmd, MR_Event_Info *event_info,
+		MR_Event_Details *event_details, MR_Code **jumpaddr)
 {
 	MR_Retry_Result		result;
 	const MR_Proc_Layout 	*entry;
@@ -1174,6 +1157,14 @@
 	const char		*message;
 	MR_Trace_Level		trace_level;
 
+	if (!MR_port_is_final(event_info->MR_trace_port)) {
+		fflush(MR_mdb_out);
+		fprintf(MR_mdb_err,
+			"mdb: declarative debugging is only available"
+			" from EXIT, FAIL or EXCP events.\n");
+		return FALSE;
+	}
+
 	entry = event_info->MR_event_sll->MR_sll_entry;
 	if (!MR_ENTRY_LAYOUT_HAS_EXEC_TRACE(entry)) {
 		fflush(MR_mdb_out);
@@ -1212,11 +1203,7 @@
 	}
 #endif /* MR_USE_DECL_STACK_SLOT */
 
-	if (outfile == (const char *) NULL) {
-		/* Normal debugging mode */
-		MR_trace_decl_mode = MR_TRACE_DECL_DEBUG;
-	} else {
-		/* Test mode */
+	if (trace_mode == MR_TRACE_DECL_DEBUG_DUMP) {
 		out = fopen(outfile, "w");
 		if (out == NULL) {
 			fflush(MR_mdb_out);
@@ -1225,11 +1212,12 @@
 					outfile, strerror(errno));
 			return FALSE;
 		} else {
-			MR_trace_decl_mode = MR_TRACE_DECL_DEBUG_TEST;
 			MR_trace_store_file = out;
 		}
 	}
 
+	MR_trace_decl_mode = trace_mode;
+
 	MR_trace_decl_ensure_init();
 	depth_limit = event_info->MR_call_depth + MR_EDT_DEPTH_STEP_SIZE;
 	message = MR_trace_start_collecting(event_info->MR_event_number,
@@ -1339,21 +1327,37 @@
 	MR_Unsigned		bug_event;
 	MR_Unsigned		final_event;
 	MR_Unsigned		topmost_seqno;
+	MercuryFile		stream;
 
-#if 0
-	/*
-	** This is a quick and dirty way to debug the front end.
-	*/
-	MR_trace_enabled = TRUE;
-#endif
-
 	if (MR_edt_compiler_flag_warning) {
+		fflush(MR_mdb_out);
 		fprintf(MR_mdb_err, "Warning: some modules were compiled with"
 				" a trace level lower than `decl'.\n"
 				"This may result in calls being omitted from"
 				" the debugging tree.\n");
 	}
 
+	if (MR_trace_decl_mode == MR_TRACE_DECL_DEBUG_DUMP) {
+		MR_mercuryfile_init(MR_trace_store_file, 1, &stream);
+
+		MR_TRACE_CALL_MERCURY(
+			MR_DD_save_trace((MR_Word) &stream,
+						MR_trace_node_store, root);
+		);
+
+		fclose(MR_trace_store_file);
+		MR_trace_decl_mode = MR_TRACE_INTERACTIVE;
+		MR_trace_enabled = TRUE;
+		return MR_trace_event_internal(cmd, TRUE, event_info);
+	}
+
+	if (MR_trace_decl_mode == MR_TRACE_DECL_DEBUG_DEBUG) {
+		/*
+		** This is a quick and dirty way to debug the front end.
+		*/
+		MR_trace_enabled = TRUE;
+	}
+
 	MR_TRACE_CALL_MERCURY(
 		MR_DD_decl_diagnosis(MR_trace_node_store, root, &response,
 				MR_trace_front_end_state,
@@ -1435,20 +1439,6 @@
 	MR_trace_decl_mode = MR_TRACE_INTERACTIVE;
 	MR_trace_enabled = TRUE;
 	return jumpaddr;
-}
-
-static	void
-MR_decl_diagnosis_test(MR_Trace_Node root)
-{
-	MercuryFile stream;
-
-	MR_mercuryfile_init(MR_trace_store_file, 1, &stream);
-
-	MR_TRACE_CALL_MERCURY(
-		MR_DD_save_trace((MR_Word) &stream, MR_trace_node_store, root);
-	);
-
-	fclose(MR_trace_store_file);
 }
 
 static	MR_String
Index: trace/mercury_trace_declarative.h
===================================================================
RCS file: /home/mercury1/repository/mercury/trace/mercury_trace_declarative.h,v
retrieving revision 1.11
diff -u -r1.11 mercury_trace_declarative.h
--- trace/mercury_trace_declarative.h	2000/10/16 01:34:10	1.11
+++ trace/mercury_trace_declarative.h	2001/04/26 17:38:59
@@ -9,6 +9,7 @@
 
 #include "mercury_imp.h"
 #include "mercury_trace.h"
+#include "mercury_trace_internal.h"
 
 /*
 ** When in declarative debugging mode, the internal debugger calls
@@ -25,8 +26,9 @@
 ** being entered.
 */
 
-extern	bool	MR_trace_start_decl_debug(const char *out,
-			MR_Trace_Cmd_Info *cmd, MR_Event_Info *event_info,
+extern	bool	MR_trace_start_decl_debug(MR_Trace_Mode trace_mode,
+			const char *out, MR_Trace_Cmd_Info *cmd,
+			MR_Event_Info *event_info,
 			MR_Event_Details *event_details, MR_Code **jumpaddr);
 
 /*
Index: trace/mercury_trace_internal.c
===================================================================
RCS file: /home/mercury1/repository/mercury/trace/mercury_trace_internal.c,v
retrieving revision 1.101
diff -u -r1.101 mercury_trace_internal.c
--- trace/mercury_trace_internal.c	2001/04/03 05:33:51	1.101
+++ trace/mercury_trace_internal.c	2001/04/26 17:38:59
@@ -2076,44 +2076,42 @@
 		}
 #ifdef	MR_USE_DECLARATIVE_DEBUGGER
 	} else if (streq(words[0], "dd")) {
-		MR_Trace_Port	port = event_info->MR_trace_port;
-
 		if (word_count != 1) {
 			fflush(MR_mdb_out);
 			fprintf(MR_mdb_err,
 				"mdb: dd requires no arguments.\n");
-		} else if (MR_port_is_final(port)) {
-			if (MR_trace_start_decl_debug((const char *) NULL, cmd,
+		} else {
+			if (MR_trace_start_decl_debug(MR_TRACE_DECL_DEBUG,
+						(const char *) NULL, cmd,
 						event_info, event_details,
 						jumpaddr))
 			{
 				return STOP_INTERACTING;
 			}
-		} else {
-			fflush(MR_mdb_out);
-			fprintf(MR_mdb_err,
-				"mdb: declarative debugging is only "
-				"available from EXIT, FAIL or EXCP events.\n");
 		}
         } else if (streq(words[0], "dd_dd")) {
-		MR_Trace_Port	port = event_info->MR_trace_port;
+		MR_Trace_Mode	trace_mode;
+		const char	*filename;
 
-		if (word_count != 2) {
+		if (word_count > 2) {
 			fflush(MR_mdb_out);
 			fprintf(MR_mdb_err,
-				"mdb: dd_dd requires one argument.\n");
-		} else if (MR_port_is_final(port)) {
-			if (MR_trace_start_decl_debug((const char *) words[1],
+				"mdb: dd_dd takes at most one argument.\n");
+		} else {
+			if (word_count == 2) {
+				trace_mode = MR_TRACE_DECL_DEBUG_DUMP;
+				filename = (const char *) words[1];
+			} else {
+				trace_mode = MR_TRACE_DECL_DEBUG_DEBUG;
+				filename = (const char *) NULL;
+			}
+
+			if (MR_trace_start_decl_debug(trace_mode, filename,
 						cmd, event_info, event_details,
 						jumpaddr))
 			{
 				return STOP_INTERACTING;
 			}
-		} else {
-			fflush(MR_mdb_out);
-			fprintf(MR_mdb_err,
-				"mdb: declarative debugging is only "
-				"available from EXIT, FAIL or EXCP events.\n");
 		}
 #endif  /* MR_USE_DECLARATIVE_DEBUGGER */
 	} else {
Index: trace/mercury_trace_internal.h
===================================================================
RCS file: /home/mercury1/repository/mercury/trace/mercury_trace_internal.h,v
retrieving revision 1.13
diff -u -r1.13 mercury_trace_internal.h
--- trace/mercury_trace_internal.h	2000/10/16 01:34:14	1.13
+++ trace/mercury_trace_internal.h	2001/04/26 18:34:52
@@ -24,7 +24,14 @@
 typedef enum {
 	MR_TRACE_INTERACTIVE,	 	/* Use internal debugger. */
 	MR_TRACE_DECL_DEBUG,		/* Normal declarative debugging. */
-	MR_TRACE_DECL_DEBUG_TEST	/* Test mode declarative debugging. */
+	MR_TRACE_DECL_DEBUG_DUMP,	/*
+					** Output debugging info to a file
+					** for separate analysis.
+					*/
+	MR_TRACE_DECL_DEBUG_DEBUG	/*
+					** Generate trace events for the
+					** debugging front end.
+					*/
 } MR_Trace_Mode;
 
 /*
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