Reorganizing source code. Created util dir

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/util/trace.cpp

@@ -0,0 +1,68 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    trace.cpp
+
+Abstract:
+
+    Trace message support.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2006-09-13.
+
+Revision History:
+
+--*/
+#include"trace.h"
+#include"str_hashtable.h"
+
+#ifdef _TRACE
+std::ofstream tout(".z3-trace"); 
+#endif
+
+bool g_enable_all_trace_tags = false;
+str_hashtable* g_enabled_trace_tags = 0;
+
+static str_hashtable& get_enabled_trace_tags() {
+    if (!g_enabled_trace_tags) {
+        g_enabled_trace_tags = alloc(str_hashtable);
+    }
+    return *g_enabled_trace_tags;
+}
+
+void finalize_trace() {
+    dealloc(g_enabled_trace_tags);
+    g_enabled_trace_tags = 0;
+}
+
+void enable_trace(const char * tag) {
+    get_enabled_trace_tags().insert(const_cast<char *>(tag));
+}
+
+void enable_all_trace(bool flag) {
+    g_enable_all_trace_tags = flag;
+}
+
+void disable_trace(const char * tag) {
+    get_enabled_trace_tags().erase(const_cast<char *>(tag));
+}
+
+bool is_trace_enabled(const char * tag) {
+    return g_enable_all_trace_tags || 
+		(g_enabled_trace_tags && get_enabled_trace_tags().contains(const_cast<char *>(tag)));
+}
+
+void close_trace() {
+#ifdef _TRACE
+    tout.close();
+#endif
+}
+
+void open_trace() {
+#ifdef _TRACE
+    tout.open(".z3-trace");
+#endif
+}