Use one statement preprocessor per function.

src/main/scala/millfork/compiler/AbstractStatementCompiler.scala

@@ -12,11 +12,9 @@ import millfork.node._
 abstract class AbstractStatementCompiler[T <: AbstractCode] {
 
   def compile(ctx: CompilationContext, statements: List[ExecutableStatement]): List[T] = {
-    getStatementPreprocessor(ctx, statements)().flatMap(s => compile(ctx, s))
+    statements.flatMap(s => compile(ctx, s))
   }
 
-  def getStatementPreprocessor(ctx: CompilationContext, statements: List[ExecutableStatement]): AbstractStatementPreprocessor
-
   def compile(ctx: CompilationContext, statement: ExecutableStatement): List[T]
 
   def labelChunk(labelName: String): List[T]

src/main/scala/millfork/compiler/mos/MosCompiler.scala

@@ -15,7 +15,7 @@ object MosCompiler extends AbstractCompiler[AssemblyLine] {
 
   override def compile(ctx: CompilationContext): List[AssemblyLine] = {
     ctx.env.nameCheck(ctx.function.code)
-    val chunk = MosStatementCompiler.compile(ctx, ctx.function.code)
+    val chunk = MosStatementCompiler.compile(ctx, new MosStatementPreprocessor(ctx, ctx.function.code)())
     val zpRegisterSize = ctx.options.zpRegisterSize
 
     val storeParamsFromRegisters = ctx.function.params match {

src/main/scala/millfork/compiler/mos/MosStatementCompiler.scala

@@ -307,7 +307,4 @@ object MosStatementCompiler extends AbstractStatementCompiler[AssemblyLine] {
     }
     AssemblyLine.implied(TSX) :: (List.fill(m.stackVariablesSize)(AssemblyLine.implied(INX)) :+ AssemblyLine.implied(TXS)) // this TXS is fine, it won't appear in 65816 code
   }
-
-  override def getStatementPreprocessor(ctx: CompilationContext, statements: List[ExecutableStatement]): AbstractStatementPreprocessor =
-    new MosStatementPreprocessor(ctx, statements)
 }

src/main/scala/millfork/compiler/z80/Z80Compiler.scala

@@ -13,7 +13,7 @@ object Z80Compiler extends AbstractCompiler[ZLine] {
 
   override def compile(ctx: CompilationContext): List[ZLine] = {
     ctx.env.nameCheck(ctx.function.code)
-    val chunk = Z80StatementCompiler.compile(ctx, ctx.function.code)
+    val chunk = Z80StatementCompiler.compile(ctx, new Z80StatementPreprocessor(ctx, ctx.function.code)())
     val label = ZLine.label(Label(ctx.function.name)).copy(elidable = false)
     val storeParamsFromRegisters = ctx.function.params match {
       case NormalParamSignature(List(param)) if param.typ.size == 1 =>

src/main/scala/millfork/compiler/z80/Z80StatementCompiler.scala

@@ -265,7 +265,4 @@ object Z80StatementCompiler extends AbstractStatementCompiler[ZLine] {
 
   override def compileExpressionForBranching(ctx: CompilationContext, expr: Expression, branching: BranchSpec): List[ZLine] =
     Z80ExpressionCompiler.compile(ctx, expr, ZExpressionTarget.NOTHING, branching)
-
-  override def getStatementPreprocessor(ctx: CompilationContext, statements: List[ExecutableStatement]): AbstractStatementPreprocessor =
-    new Z80StatementPreprocessor(ctx, statements)
 }