1 files changed, 12 insertions, 3 deletions
diff --git a/compiler/vmdef.nim b/compiler/vmdef.nim
index cad48abea..d7cdafb69 100644
--- a/compiler/vmdef.nim
+++ b/compiler/vmdef.nim
@@ -1,6 +1,6 @@
 #
 #
-#           The Nimrod Compiler
+#           The Nim Compiler
 #        (c) Copyright 2013 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
@@ -170,7 +170,12 @@ type
     sym*: PSym
     slots*: array[TRegister, tuple[inUse: bool, kind: TSlotKind]]
     maxSlots*: int
-    
+
+  VmArgs* = object
+    ra*, rb*, rc*: Natural
+    slots*: pointer
+  VmCallback* = proc (args: VmArgs) {.closure.}
+  
   PCtx* = ref TCtx
   TCtx* = object of passes.TPassContext # code gen context
     code*: seq[TInstr]
@@ -189,6 +194,7 @@ type
     traceActive*: bool
     loopIterations*: int
     comesFromHeuristic*: TLineInfo # Heuristic for better macro stack traces
+    callbacks*: seq[tuple[key: string, value: VmCallback]]
 
   TPosition* = distinct int
 
@@ -198,12 +204,15 @@ proc newCtx*(module: PSym): PCtx =
   PCtx(code: @[], debug: @[],
     globals: newNode(nkStmtListExpr), constants: newNode(nkStmtList), types: @[],
     prc: PProc(blocks: @[]), module: module, loopIterations: MaxLoopIterations,
-    comesFromHeuristic: unknownLineInfo())
+    comesFromHeuristic: unknownLineInfo(), callbacks: @[])
 
 proc refresh*(c: PCtx, module: PSym) =
   c.module = module
   c.prc = PProc(blocks: @[])
 
+proc registerCallback*(c: PCtx; name: string; callback: VmCallback) =
+  c.callbacks.add((name, callback))
+
 const
   firstABxInstr* = opcTJmp
   largeInstrs* = { # instructions which use 2 int32s instead of 1: