Add extension preprocessor directives to compiler (#13)

Author: dassjosh

src/CompilerService.cs

@@ -132,6 +132,27 @@ internal bool Precheck()
                 }
             }
 
+            foreach (Extension extension in Interface.Oxide.GetAllExtensions())
+            {
+                try
+                {
+                    string prefix = $"{extension.Name.ToUpper()}_EXT";
+                    foreach (string directive in extension.GetPreprocessorDirectives())
+                    {
+                        if (!extension.IsGameExtension && !extension.IsCoreExtension && !directive.StartsWith(prefix))
+                        {
+                            Interface.Oxide.LogWarning("Missing extension preprocessor prefix '{0}' for directive '{1}' (by extension '{2}')", prefix, directive, extension.Name);
+                        }
+
+                        preprocessorList.Add(EscapeSymbolName(directive));
+                    }
+                }
+                catch (Exception ex)
+                {
+                    Interface.Oxide.LogException($"An error occurred processing preprocessor directives for extension `{extension.Name}`", ex);
+                }
+            }
+
 #if DEBUG
             preprocessorList.Add("DEBUG");
 #endif