--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gen/configfile.cpp	Thu Mar 12 20:37:27 2009 +0100
@@ -0,0 +1,112 @@
+#include <iostream>
+#include <string>
+#include <cassert>
+
+#include "llvm/System/Path.h"
+
+#include "libconfig.h++"
+
+#include "gen/configfile.h"
+
+#include "mars.h"
+
+namespace sys = llvm::sys;
+
+ConfigFile::ConfigFile()
+{
+    cfg = new libconfig::Config;
+}
+
+ConfigFile::~ConfigFile()
+{
+    delete cfg;
+}
+
+bool ConfigFile::read(const char* argv0, void* mainAddr, const char* filename)
+{
+
+    // try to find the config file
+
+    // 1) try the current working dir
+    sys::Path p = sys::Path::GetCurrentDirectory();
+    p.appendComponent(filename);
+
+    if (!p.exists())
+    {
+        // 2) try the user home dir
+        p = sys::Path::GetUserHomeDirectory();
+        p.appendComponent(filename);
+
+        if (!p.exists())
+        {
+            // 3) try the install-prefix/etc
+            p = sys::Path(LDC_INSTALL_PREFIX);
+            p.appendComponent(filename);
+
+            if (!p.exists())
+            {
+                // 4) try next to the executable
+                p = sys::Path::GetMainExecutable(argv0, mainAddr);
+                p.eraseComponent();
+                p.appendComponent(filename);
+                if (!p.exists())
+                {
+                    // 5) fail load cfg, users still have the DFLAGS environment var
+                    std::cerr << "Error failed to locate the configuration file: " << filename << std::endl;
+                    return false;
+                }
+            }
+        }
+    }
+
+    try
+    {
+        // read the cfg
+        cfg->readFile(p.c_str());
+
+        // make sure there's a default group
+        if (!cfg->exists("default"))
+        {
+            std::cerr << "no default settings in configuration file" << std::endl;
+            return false;
+        }
+        libconfig::Setting& root = cfg->lookup("default");
+        if (!root.isGroup())
+        {
+            std::cerr << "default is not a group" << std::endl;
+            return false;
+        }
+
+        // handle switches
+        if (root.exists("switches"))
+        {
+            libconfig::Setting& arr = cfg->lookup("default.switches");
+            int len = arr.getLength();
+            for (int i=0; i<len; i++)
+            {
+                const char* v = arr[i];
+                switches.push_back(v);
+            }
+        }
+
+    }
+    catch(libconfig::FileIOException& fioe)
+    {
+        std::cerr << "Error reading configuration file: " << filename << std::endl;
+        return false;
+    }
+    catch(libconfig::ParseException& pe)
+    {
+        std::cerr << "Error parsing configuration file: " << filename
+            << "(" << pe.getLine() << "): " << pe.getError() << std::endl;
+        return false;
+    }
+    catch(...)
+    {
+        std::cerr << "Unknown exception caught!" << std::endl;
+        return false;
+    }
+
+    return true;
+}
+