Fix FileSpec::IsSymlink implementation.

[ovyalov]

Summary

stat call returns information about target file in case of symbolic link.
In order to query symlink status we can use lstat on POSIX systems and GetFileAttributes on Windows.

[amccarth]

Looks good to me.

[clayborg]

Looks good.

[ovyalov]

Files:

/lldb/trunk/include/lldb/Host/FileSpec.h
/lldb/trunk/source/Host/common/FileSpec.cpp

Users:

ovyalov (Author)

http://reviews.llvm.org/rL242753

include/lldb/Host/FileSpec.h

public:
 
     bool
     IsSocket () const
     {
         return GetFileType() == FileSpec::eFileTypeSocket;
     }
 
     bool
-    IsSymbolicLink () const
-    {
-        return GetFileType() == FileSpec::eFileTypeSymbolicLink;
-    }
+    IsSymbolicLink () const;
 
     //------------------------------------------------------------------
     /// Get the memory cost of this object.
     ///
     /// Return the size in bytes that this object takes in memory. This
     /// returns the size in bytes of this object, not any shared string
     /// values it may refer to.
     ///

source/Host/common/FileSpec.cpp

#endif
         default:
             break;
         }
         return eFileTypeUnknown;
     }
     return eFileTypeInvalid;
 }
 
+bool
+FileSpec::IsSymbolicLink () const
+{
+    char resolved_path[PATH_MAX];
+    if (!GetPath (resolved_path, sizeof (resolved_path)))
+        return false;
+
+#ifdef _WIN32
+    auto attrs = ::GetFileAttributes (resolved_path);
+    if (attrs == INVALID_FILE_ATTRIBUTES)
+        return false;
+
+    return (attrs & FILE_ATTRIBUTE_REPARSE_POINT);
+#else
+    struct stat file_stats;
+    if (::lstat (resolved_path, &file_stats) != 0)
+        return false;
+
+    return (file_stats.st_mode & S_IFMT) == S_IFLNK;
+#endif
+}
+
 uint32_t
 FileSpec::GetPermissions () const
 {
     uint32_t file_permissions = 0;
     if (*this)
         FileSystem::GetFilePermissions(*this, file_permissions);
     return file_permissions;
 }