From 78f985af0e2d41a1cf6fb7b3b81928c17728f9e9 Mon Sep 17 00:00:00 2001
From: Cary R <cygcary@yahoo.com>
Date: Thu, 3 Mar 2011 18:54:46 -0800
Subject: [PATCH] Add trace command to interactive prompt to control statement
 tracing.

This patch adds a trace command to the interactive prompt that can be
used to control statement tracing when the code is instrumented (has
%file_line opcodes).
---
 vvp/file_line.cc |  2 ++
 vvp/stop.cc      | 34 +++++++++++++++++++++++++++++++++-
 vvp/vpi_priv.h   |  1 +
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/vvp/file_line.cc b/vvp/file_line.cc
index 6f8198be5..924f7d710 100644
--- a/vvp/file_line.cc
+++ b/vvp/file_line.cc
@@ -27,6 +27,7 @@ struct __vpiFileLine {
 };
 
 bool show_file_line = false;
+bool code_is_instrumented = false;
 
 static int file_line_get(int type, vpiHandle ref)
 {
@@ -80,6 +81,7 @@ vpiHandle vpip_build_file_line(char*description, long file_idx, long lineno)
 
 	/* Turn on the diagnostic output when we find a %file_line. */
       show_file_line = true;
+      code_is_instrumented = true;
 
       obj->base.vpi_type = &vpip_file_line_rt;
       if (description) obj->description = vpip_name_string(description);
diff --git a/vvp/stop.cc b/vvp/stop.cc
index 07af64487..438a8785a 100644
--- a/vvp/stop.cc
+++ b/vvp/stop.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003-2010 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2003-2011 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -357,6 +357,36 @@ static void cmd_time(unsigned, char*[])
       printf("%lu ticks\n", ticks);
 }
 
+static void cmd_trace(unsigned argc, char*argv[])
+{
+      assert(argc);
+      switch (argc) {
+	case 1:
+	    show_file_line = true;
+	    break;
+	default:
+	    printf("Only using the first argument to trace.\n");
+	case 2:
+	    if ((strcmp(argv[1], "on") == 0) || (strcmp(argv[1], "1") == 0)) {
+		  show_file_line = true;
+	    } else show_file_line = false;
+	    break;
+      }
+
+	/* You can't trace a file if the compiler didn't insert the
+	 * %file_line opcodes. */
+      if (!code_is_instrumented) {
+	    printf("The vvp input must be instrumented before tracing is "
+	           "available.\n");
+	    printf("Recompile with the -pfileline=1 flag to instrument "
+	           "the input.\n");
+	    show_file_line = false;
+      } else {
+	    printf("Turning statement tracing %s.\n",
+	           show_file_line ? "on" : "off");
+      }
+}
+
 static void cmd_where(unsigned, char*[])
 {
       struct __vpiScope*cur = stop_current_scope;
@@ -412,6 +442,8 @@ static struct {
         "Single-step the scheduler for 1 event."},
       { "time",   &cmd_time,
         "Print the current simulation time."},
+      { "trace",   &cmd_trace,
+        "Control statement tracing (on/off) when the code is instrumented."},
       { "where",  &cmd_where,
         "Show current scope, and scope hierarchy stack."},
       { 0,        &cmd_unknown, 0}
diff --git a/vvp/vpi_priv.h b/vvp/vpi_priv.h
index 49209dcfa..71c859fbc 100644
--- a/vvp/vpi_priv.h
+++ b/vvp/vpi_priv.h
@@ -45,6 +45,7 @@
 #define _vpiDescription 0x1000004
 
 extern bool show_file_line;
+extern bool code_is_instrumented;
 
 extern vpiHandle vpip_build_file_line(char*description,
                                       long file_idx, long lineno);