Handler runtime improvements

hkmc2/shared/src/main/scala/hkmc2/codegen/StackSafeTransform.scala

@@ -9,19 +9,19 @@ import hkmc2.semantics.*
 import hkmc2.syntax.Tree
 
 class StackSafeTransform(depthLimit: Int)(using State):
-  private val STACK_LIMIT_IDENT: Tree.Ident = Tree.Ident("__stackLimit")
-  private val STACK_DEPTH_IDENT: Tree.Ident = Tree.Ident("__stackDepth")
-  private val STACK_OFFSET_IDENT: Tree.Ident = Tree.Ident("__stackOffset")
-  private val STACK_HANDLER_IDENT: Tree.Ident = Tree.Ident("__stackHandler")
-
-  private val predefPath: Path = State.globalThisSymbol.asPath.selN(Tree.Ident("Predef"))
-  private val checkDepthPath: Path = predefPath.selN(Tree.Ident("checkDepth"))
-  private val resetDepthPath: Path = predefPath.selN(Tree.Ident("resetDepth"))
-  private val stackDelayClsPath: Path = predefPath.selN(Tree.Ident("__StackDelay"))
-  private val stackLimitPath: Path = predefPath.selN(STACK_LIMIT_IDENT)
-  private val stackDepthPath: Path = predefPath.selN(STACK_DEPTH_IDENT)
-  private val stackOffsetPath: Path = predefPath.selN(STACK_OFFSET_IDENT)
-  private val stackHandlerPath: Path = predefPath.selN(STACK_HANDLER_IDENT)
+  private val STACK_LIMIT_IDENT: Tree.Ident = Tree.Ident("stackLimit")
+  private val STACK_DEPTH_IDENT: Tree.Ident = Tree.Ident("stackDepth")
+  private val STACK_OFFSET_IDENT: Tree.Ident = Tree.Ident("stackOffset")
+  private val STACK_HANDLER_IDENT: Tree.Ident = Tree.Ident("stackHandler")
+
+  private val runtimePath: Path = State.runtimeSymbol.asPath
+  private val checkDepthPath: Path = runtimePath.selN(Tree.Ident("checkDepth"))
+  private val resetDepthPath: Path = runtimePath.selN(Tree.Ident("resetDepth"))
+  private val stackDelayClsPath: Path = runtimePath.selN(Tree.Ident("StackDelay"))
+  private val stackLimitPath: Path = runtimePath.selN(STACK_LIMIT_IDENT)
+  private val stackDepthPath: Path = runtimePath.selN(STACK_DEPTH_IDENT)
+  private val stackOffsetPath: Path = runtimePath.selN(STACK_OFFSET_IDENT)
+  private val stackHandlerPath: Path = runtimePath.selN(STACK_HANDLER_IDENT)
 
   private def intLit(n: BigInt) = Value.Lit(Tree.IntLit(n))
 
@@ -33,13 +33,13 @@ class StackSafeTransform(depthLimit: Int)(using State):
   def extractRes(res: Result, isTailCall: Bool, f: Result => Block, sym: Option[Symbol], curDepth: => Symbol) =
     if isTailCall then
       blockBuilder
-        .assignFieldN(predefPath, STACK_DEPTH_IDENT, op("+", stackDepthPath, intLit(1)))
+        .assignFieldN(runtimePath, STACK_DEPTH_IDENT, op("+", stackDepthPath, intLit(1)))
         .ret(res)
     else
       val tmp = sym getOrElse TempSymbol(None, "tmp")
       val offsetGtDepth = TempSymbol(None, "offsetGtDepth")
       blockBuilder
-        .assignFieldN(predefPath, STACK_DEPTH_IDENT, op("+", stackDepthPath, intLit(1)))
+        .assignFieldN(runtimePath, STACK_DEPTH_IDENT, op("+", stackDepthPath, intLit(1)))
         .assign(tmp, res)
         .assign(tmp, Call(resetDepthPath, tmp.asPath.asArg :: curDepth.asPath.asArg :: Nil)(true, false))
         .rest(f(tmp.asPath))
@@ -48,7 +48,6 @@ class StackSafeTransform(depthLimit: Int)(using State):
     val resumeSym = VarSymbol(Tree.Ident("resume"))
     val handlerSym = TempSymbol(None, "stackHandler")
     val resSym = sym getOrElse TempSymbol(None, "res")
-    val handlerRes = TempSymbol(None, "res")
 
     val clsSym = ClassSymbol(
       Tree.TypeDef(syntax.Cls, Tree.Error(), N, N),
@@ -64,23 +63,21 @@ class StackSafeTransform(depthLimit: Int)(using State):
         /* 
           fun perform() =
             stackOffset = stackDepth
-            let ret = resume()
-            ret
+            resume()
         */
         blockBuilder
-          .assignFieldN(predefPath, STACK_OFFSET_IDENT, stackDepthPath)
-          .assign(handlerRes, Call(Value.Ref(resumeSym), Nil)(true, true))
-          .ret(handlerRes.asPath)
+          .assignFieldN(runtimePath, STACK_OFFSET_IDENT, stackDepthPath)
+          .ret(Call(Value.Ref(resumeSym), Nil)(true, true))
       ) :: Nil,
       blockBuilder
-        .assignFieldN(predefPath, STACK_LIMIT_IDENT, intLit(depthLimit)) // set stackLimit before call
-        .assignFieldN(predefPath, STACK_OFFSET_IDENT, intLit(0)) // set stackOffset = 0 before call
-        .assignFieldN(predefPath, STACK_DEPTH_IDENT, intLit(1)) // set stackDepth = 1 before call
-        .assignFieldN(predefPath, STACK_HANDLER_IDENT, handlerSym.asPath) // assign stack handler
+        .assignFieldN(runtimePath, STACK_LIMIT_IDENT, intLit(depthLimit)) // set stackLimit before call
+        .assignFieldN(runtimePath, STACK_OFFSET_IDENT, intLit(0)) // set stackOffset = 0 before call
+        .assignFieldN(runtimePath, STACK_DEPTH_IDENT, intLit(1)) // set stackDepth = 1 before call
+        .assignFieldN(runtimePath, STACK_HANDLER_IDENT, handlerSym.asPath) // assign stack handler
         .rest(HandleBlockReturn(res)),
       blockBuilder // reset the stack safety values
-        .assignFieldN(predefPath, STACK_DEPTH_IDENT, intLit(0)) // set stackDepth = 0 after call
-        .assignFieldN(predefPath, STACK_HANDLER_IDENT, Value.Lit(Tree.UnitLit(true))) // set stackHandler = null
+        .assignFieldN(runtimePath, STACK_DEPTH_IDENT, intLit(0)) // set stackDepth = 0 after call
+        .assignFieldN(runtimePath, STACK_HANDLER_IDENT, Value.Lit(Tree.UnitLit(true))) // set stackHandler = null
         .rest(f(resSym.asPath))
     )
 

hkmc2/shared/src/main/scala/hkmc2/semantics/Elaborator.scala

@@ -103,6 +103,7 @@ object Elaborator:
       val untyped = assumeBuiltinTpe("untyped")
       // println(s"Builtins: $Int, $Num, $Str, $untyped")
       val Predef = assumeBuiltinMod("Predef")
+      val Runtime = assumeBuiltinMod("Runtime")
       def getBuiltinOp(op: Str): Opt[Str] =
         if getBuiltin(op).isDefined then builtinBinOps.get(op) else N
       /** Classes that do not use `instanceof` in pattern matching. */