1 files changed, 46 insertions, 39 deletions
diff --git a/compiler/vmhooks.nim b/compiler/vmhooks.nim
index 548a3af97..2d7ad63e7 100644
--- a/compiler/vmhooks.nim
+++ b/compiler/vmhooks.nim
@@ -7,13 +7,14 @@
 #    distribution, for details about the copyright.
 #
 
+import pathutils
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 template setX(k, field) {.dirty.} =
-  var s: seq[TFullReg]
-  move(s, cast[seq[TFullReg]](a.slots))
-  if s[a.ra].kind != k:
-    myreset(s[a.ra])
-    s[a.ra].kind = k
-  s[a.ra].field = v
+  a.slots[a.ra].ensureKind(k)
+  a.slots[a.ra].field = v
 
 proc setResult*(a: VmArgs; v: BiggestInt) = setX(rkInt, intVal)
 proc setResult*(a: VmArgs; v: BiggestFloat) = setX(rkFloat, floatVal)
@@ -22,49 +23,55 @@ proc setResult*(a: VmArgs; v: bool) =
   setX(rkInt, intVal)
 
 proc setResult*(a: VmArgs; v: string) =
-  var s: seq[TFullReg]
-  move(s, cast[seq[TFullReg]](a.slots))
-  if s[a.ra].kind != rkNode:
-    myreset(s[a.ra])
-    s[a.ra].kind = rkNode
-  s[a.ra].node = newNode(nkStrLit)
-  s[a.ra].node.strVal = v
+  a.slots[a.ra].ensureKind(rkNode)
+  a.slots[a.ra].node = newNode(nkStrLit)
+  a.slots[a.ra].node.strVal = v
 
 proc setResult*(a: VmArgs; n: PNode) =
-  var s: seq[TFullReg]
-  move(s, cast[seq[TFullReg]](a.slots))
-  if s[a.ra].kind != rkNode:
-    myreset(s[a.ra])
-    s[a.ra].kind = rkNode
-  s[a.ra].node = n
+  a.slots[a.ra].ensureKind(rkNode)
+  a.slots[a.ra].node = n
+
+proc setResult*(a: VmArgs; v: AbsoluteDir) = setResult(a, v.string)
 
 proc setResult*(a: VmArgs; v: seq[string]) =
-  var s: seq[TFullReg]
-  move(s, cast[seq[TFullReg]](a.slots))
-  if s[a.ra].kind != rkNode:
-    myreset(s[a.ra])
-    s[a.ra].kind = rkNode
+  a.slots[a.ra].ensureKind(rkNode)
   var n = newNode(nkBracket)
   for x in v: n.add newStrNode(nkStrLit, x)
-  s[a.ra].node = n
+  a.slots[a.ra].node = n
+
+proc setResult*(a: VmArgs; v: (BiggestInt, BiggestInt)) =
+  a.slots[a.ra].ensureKind(rkNode)
+  var tuplen = newNode(nkTupleConstr)
+  tuplen.add newIntNode(nkIntLit, v[0])
+  tuplen.add newIntNode(nkIntLit, v[1]) 
+  a.slots[a.ra].node = tuplen
 
-template getX(k, field) {.dirty.} =
+template getReg(a, i): untyped =
   doAssert i < a.rc-1
-  let s = cast[seq[TFullReg]](a.slots)
-  doAssert s[i+a.rb+1].kind == k
-  result = s[i+a.rb+1].field
+  a.slots[i+a.rb+1].unsafeAddr
+
+template getX(k, field): untyped {.dirty.} =
+  let p = getReg(a, i)
+  doAssert p.kind == k, $p.kind
+  p.field
+
+proc numArgs*(a: VmArgs): int =
+  result = a.rc-1
 
 proc getInt*(a: VmArgs; i: Natural): BiggestInt = getX(rkInt, intVal)
 proc getBool*(a: VmArgs; i: Natural): bool = getInt(a, i) != 0
 proc getFloat*(a: VmArgs; i: Natural): BiggestFloat = getX(rkFloat, floatVal)
-proc getString*(a: VmArgs; i: Natural): string =
-  doAssert i < a.rc-1
-  let s = cast[seq[TFullReg]](a.slots)
-  doAssert s[i+a.rb+1].kind == rkNode
-  result = s[i+a.rb+1].node.strVal
+proc getNode*(a: VmArgs; i: Natural): PNode = getX(rkNode, node)
+proc getString*(a: VmArgs; i: Natural): string = getX(rkNode, node).strVal
+proc getVar*(a: VmArgs; i: Natural): PNode =
+  let p = getReg(a, i)
+  # depending on whether we come from top-level or proc scope, we need to consider 2 cases
+  case p.kind
+  of rkRegisterAddr: result = p.regAddr.node
+  of rkNodeAddr: result = p.nodeAddr[]
+  else: raiseAssert $p.kind
 
-proc getNode*(a: VmArgs; i: Natural): PNode =
-  doAssert i < a.rc-1
-  let s = cast[seq[TFullReg]](a.slots)
-  doAssert s[i+a.rb+1].kind == rkNode
-  result = s[i+a.rb+1].node
+proc getNodeAddr*(a: VmArgs; i: Natural): PNode =
+  let nodeAddr = getX(rkNodeAddr, nodeAddr)
+  doAssert nodeAddr != nil
+  result = nodeAddr[]