Reorganizing the code

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

src/api/api_log.cpp

@@ -0,0 +1,54 @@
+/*++
+Copyright (c) 2012 Microsoft Corporation
+
+Module Name:
+
+    api_log.cpp
+
+Abstract:
+    API for creating logs
+
+Author:
+
+    Leonardo de Moura (leonardo) 2012-02-29.
+
+Revision History:
+
+--*/
+#include<iostream>
+#include<fstream>
+#include"z3.h"
+#include"api_log_macros.h"
+#include"util.h"
+
+std::ostream * g_z3_log = 0;
+bool g_z3_log_enabled   = false;
+
+extern "C" {
+    Z3_bool Z3_API Z3_open_log(Z3_string filename) {
+        if (g_z3_log != 0)
+            Z3_close_log();
+        g_z3_log = alloc(std::ofstream, filename);
+        g_z3_log_enabled = true;
+        if (g_z3_log->bad() || g_z3_log->fail()) {
+            dealloc(g_z3_log);
+            g_z3_log = 0;
+            return Z3_FALSE;
+        }
+        return Z3_TRUE;
+    }
+
+    void Z3_API Z3_append_log(Z3_string str) {
+        if (g_z3_log == 0)
+            return;
+        _Z3_append_log(static_cast<char const *>(str));
+    }
+
+    void Z3_API Z3_close_log() {
+        if (g_z3_log != 0) {
+            dealloc(g_z3_log);
+            g_z3_log_enabled = false;
+            g_z3_log = 0;
+        }
+    }
+}