Stub out a Path::GetMainExecutable call to find the path to the
main executable of a program.  This needs to be implemented on windows.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47835 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Unix/Path.inc b/lib/System/Unix/Path.inc
index c8bdd08..8e76b54 100644
--- a/lib/System/Unix/Path.inc
+++ b/lib/System/Unix/Path.inc
@@ -47,6 +47,10 @@
 # endif
 #endif
 
+#if HAVE_DLFCN_H
+#include <dlfcn.h>
+#endif
+
 // Put in a hack for Cygwin which falsely reports that the mkdtemp function
 // is available when it is not.
 #ifdef __CYGWIN__
@@ -244,6 +248,20 @@
   return Path(pathname);
 }
 
+/// GetMainExecutable - Return the path to the main executable, given the
+/// value of argv[0] from program startup.
+Path Path::GetMainExecutable(const char *argv0, void *MainAddr) {
+  // Use dladdr to get executable path if available.
+#ifdef HAVE_DLFCN_H
+  Dl_info DLInfo;
+  int err = dladdr(MainAddr, &DLInfo);
+  if (err != 0)
+    return Path(std::string(DLInfo.dli_fname));
+#endif
+  return Path();
+}
+
+
 std::string
 Path::getBasename() const {
   // Find the last slash