test conditional compilation

compiler/layeredtable.nim

@@ -2,11 +2,18 @@ import std/tables
 import ast
 
 type
-  LayeredIdTable* {.acyclic.} = ref object
+  LayeredIdTableObj* {.acyclic.} = object
     topLayer*: TypeMapping
-    nextLayer*: LayeredIdTable
+    nextLayer*: ref LayeredIdTableObj
     previousLen*: int # used to track if bindings were added
 
+const useRef = defined(gcMarkAndSweep)
+
+when useRef:
+  type LayeredIdTable* = ref LayeredIdTableObj
+else:
+  type LayeredIdTable* = LayeredIdTableObj
+
 proc initLayeredTypeMap*(pt: sink TypeMapping = initTypeMapping()): LayeredIdTable =
   result = LayeredIdTable(topLayer: pt, nextLayer: nil)
 
@@ -17,21 +24,41 @@ proc currentLen*(pt: LayeredIdTable): int =
   pt.previousLen + pt.topLayer.len
 
 proc newTypeMapLayer*(pt: LayeredIdTable): LayeredIdTable =
-  result = LayeredIdTable(topLayer: initTable[ItemId, PType](), nextLayer: pt, previousLen: pt.currentLen)
+  result = LayeredIdTable(topLayer: initTable[ItemId, PType](), previousLen: pt.currentLen)
+  when useRef:
+    result.nextLayer = pt
+  else:
+    new(result.nextLayer)
+    result.nextLayer[] = pt
 
 proc setToPreviousLayer*(pt: var LayeredIdTable) {.inline.} =
-  pt = pt.nextLayer
+  when useRef:
+    pt = pt.nextLayer
+  else:
+    when defined(gcDestructors):
+      pt = pt.nextLayer[]
+    else:
+      pt = shallowCopy(pt.nextLayer[])
 
-proc lookup(typeMap: LayeredIdTable, key: ItemId): PType =
+proc lookup(typeMap: ref LayeredIdTableObj, key: ItemId): PType =
   result = nil
   var tm = typeMap
   while tm != nil:
     result = getOrDefault(tm.topLayer, key)
     if result != nil: return
     tm = tm.nextLayer
 
-template lookup*(typeMap: LayeredIdTable, key: PType): PType =
+template lookup*(typeMap: ref LayeredIdTableObj, key: PType): PType =
   lookup(typeMap, key.itemId)
 
-proc put*(typeMap: LayeredIdTable, key, value: PType) {.inline.} =
+when not useRef:
+  proc lookup(typeMap: LayeredIdTableObj, key: ItemId): PType {.inline.} =
+    result = getOrDefault(typeMap.topLayer, key)
+    if result == nil and typeMap.nextLayer != nil:
+      result = lookup(typeMap.nextLayer, key)
+
+  template lookup*(typeMap: LayeredIdTableObj, key: PType): PType =
+    lookup(typeMap, key.itemId)
+
+proc put*(typeMap: var LayeredIdTable, key, value: PType) {.inline.} =
   typeMap.topLayer[key.itemId] = value