base: Reimplement the DPRINTF mechanism in a Logger class

This patch adds a Logger class encapsulating dprintf.  This allows
variants of DPRINTF logging to be constructed and substituted in
place of the default behaviour.

The Logger provides a logMessage(when, name, format, ...) member
function like Trace::dprintf and a getOstream member function to
use a raw ostream for logging.

A class OstreamLogger is provided which generates the customary
debugging output with Trace::OstreamLogger::logMessage being the
old Trace::dprintf.

1 files changed, 65 insertions, 44 deletions

diff --git a/src/base/trace.cc b/src/base/trace.cc
index 00a4c3e6b..711d49655 100644
--- a/src/base/trace.cc
+++ b/src/base/trace.cc
@@ -1,4 +1,7 @@
 /*
+ * Copyright (c) 2014 ARM Limited
+ * All rights reserved
+ *
  * Copyright (c) 2001-2006 The Regents of The University of Michigan
  * All rights reserved.
  *
@@ -27,11 +30,13 @@
  *
  * Authors: Nathan Binkert
  *          Steve Reinhardt
+ *          Andrew Bardsley
  */
 
 #include <cctype>
 #include <fstream>
 #include <iostream>
+#include <sstream>
 #include <string>
 
 #include "base/misc.hh"
@@ -39,89 +44,105 @@
 #include "base/str.hh"
 #include "base/trace.hh"
 
-using namespace std;
+const std::string &name()
+{
+    static const std::string default_name("global");
+
+    return default_name;
+}
 
-namespace Trace {
+namespace Trace
+{
 
-const string DefaultName("global");
 bool enabled = false;
 
-//
-// This variable holds the output stream for debug information.  Other
-// than setting up/redirecting this stream, do *NOT* reference this
-// directly; use DebugOut() (see below) to access this stream for
-// output.
-//
-ostream *dprintf_stream = &cerr;
-ostream &
+// This variable holds the output logger for debug information.  Other
+// than setting up/redirecting this logger, do *NOT* reference this
+// directly
+
+Logger *debug_logger = NULL;
+
+Logger *
+getDebugLogger()
+{
+    /* Set a default logger to cerr when no other logger is set */
+    if (!debug_logger)
+        debug_logger = new OstreamLogger(std::cerr);
+
+    return debug_logger;
+}
+
+std::ostream &
 output()
 {
-    return *dprintf_stream;
+    return getDebugLogger()->getOstream();
 }
 
 void
-setOutput(const string &filename)
+setDebugLogger(Logger *logger)
 {
-    dprintf_stream = simout.find(filename);
-    if (!dprintf_stream)
-        dprintf_stream = simout.create(filename);
+    if (!logger)
+        warn("Trying to set debug logger to NULL\n");
+    else
+        debug_logger = logger;
 }
 
 ObjectMatch ignore;
 
-
-bool
-__dprintf_prologue(Tick when, const std::string &name)
+void
+Logger::dump(Tick when, const std::string &name, const void *d, int len)
 {
     if (!name.empty() && ignore.match(name))
-        return false;
-
-    std::ostream &os = *dprintf_stream;
-
-    if (when != MaxTick)
-        ccprintf(os, "%7d: ", when);
+        return;
 
-    if (!name.empty())
-        os << name << ": ";
-
-    return true;
-}
-
-void
-dump(Tick when, const std::string &name, const void *d, int len)
-{
     const char *data = static_cast<const char *>(d);
-    std::ostream &os = *dprintf_stream;
     int c, i, j;
 
     for (i = 0; i < len; i += 16) {
-        if (!__dprintf_prologue(when, name))
-            return;
+        std::ostringstream line;
 
-        ccprintf(os, "%08x  ", i);
+        ccprintf(line, "%08x  ", i);
         c = len - i;
         if (c > 16) c = 16;
 
         for (j = 0; j < c; j++) {
-            ccprintf(os, "%02x ", data[i + j] & 0xff);
+            ccprintf(line, "%02x ", data[i + j] & 0xff);
             if ((j & 0xf) == 7 && j > 0)
-                ccprintf(os, " ");
+                ccprintf(line, " ");
         }
 
         for (; j < 16; j++)
-            ccprintf(os, "   ");
-        ccprintf(os, "  ");
+            ccprintf(line, "   ");
+        ccprintf(line, "  ");
 
         for (j = 0; j < c; j++) {
             int ch = data[i + j] & 0x7f;
-            ccprintf(os, "%c", (char)(isprint(ch) ? ch : ' '));
+            ccprintf(line, "%c", (char)(isprint(ch) ? ch : ' '));
         }
 
-        ccprintf(os, "\n");
+        ccprintf(line, "\n");
+        logMessage(when, name, line.str());
 
         if (c < 16)
             break;
     }
 }
 
+void
+OstreamLogger::logMessage(Tick when, const std::string &name,
+                          const std::string &message)
+{
+    if (!name.empty() && ignore.match(name))
+        return;
+
+    if (when != MaxTick)
+        ccprintf(stream, "%7d: ", when);
+
+    if (!name.empty())
+        stream << name << ": ";
+
+    stream << message;
+    stream.flush();
+}
+
 } // namespace Trace