Initial checkin


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3005 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/PluginLoader.cpp b/lib/Support/PluginLoader.cpp
new file mode 100644
index 0000000..c2e4e89
--- /dev/null
+++ b/lib/Support/PluginLoader.cpp
@@ -0,0 +1,30 @@
+//===-- PluginLoader.cpp - Implement -load command line option ------------===//
+//
+// This file implements the -load <plugin> command line option processor.  When
+// linked into a program, this new command line option is available that allows
+// users to load shared objects into the running program.
+//
+// Note that there are no symbols exported by the .o file generated for this
+// .cpp file.  Because of this, a program must link against support.o instead of
+// support.a: otherwise this translation unit will not be included.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Support/CommandLine.h"
+#include <dlfcn.h>
+#include <link.h>
+
+namespace {
+  struct PluginLoader {
+    void operator=(const std::string &Filename) {
+      if (dlopen(Filename.c_str(), RTLD_NOW) == 0)
+        std::cerr << "Error opening '" << Filename << "': " << dlerror()
+                  << "\n  -load request ignored.\n";
+    }
+  };
+}
+
+// This causes operator= above to be invoked for every -load option.
+static cl::opt<PluginLoader, false, cl::parser<string> >
+LoadOpt("load", cl::ZeroOrMore, cl::value_desc("plugin.so"),
+        cl::desc("Load the specified plugin"));