Moved register state to scopes

src/build/core/CompileDefinition.go

@@ -16,7 +16,7 @@ func (f *Function) CompileDefinition(node *ast.Define) error {
 		return errors.New(&errors.VariableAlreadyExists{Name: name}, f.File, node.Name.Position)
 	}
 
-	uses := CountIdentifier(f.Body, name) - 1
+	uses := token.Count(f.Body, token.Identifier, name) - 1
 
 	if uses == 0 {
 		return errors.New(&errors.UnusedVariable{Name: name}, f.File, node.Name.Position)
@@ -44,24 +44,30 @@ func (f *Function) AddVariable(variable *Variable) {
 		f.Comment("%s = %s (%s, %d uses)", variable.Name, variable.Value, variable.Register, variable.Alive)
 	}
 
-	f.Scope()[variable.Name] = variable
-	f.cpu.Reserve(variable.Register)
-	f.cpu.Use(variable.Register)
+	f.Scope().variables[variable.Name] = variable
+	f.Scope().Reserve(variable.Register)
+	f.Scope().Use(variable.Register)
 }
 
 func (f *Function) useVariable(variable *Variable) {
-	variable.Alive--
+	for _, scope := range f.scopes {
+		local := scope.variables[variable.Name]
 
-	if variable.Alive < 0 {
-		panic("incorrect number of variable use calls")
-	}
-
-	if variable.Alive == 0 {
-		if config.Comments {
-			f.Comment("%s died (%s)", variable.Name, variable.Register)
+		if local != nil {
+			local.Alive--
 		}
 
-		f.cpu.Free(variable.Register)
+		if local.Alive < 0 {
+			panic("incorrect number of variable use calls")
+		}
+
+		if local.Alive == 0 {
+			if config.Comments {
+				f.Comment("%s died (%s)", local.Name, local.Register)
+			}
+
+			scope.Free(local.Register)
+		}
 	}
 }
 
@@ -78,13 +84,13 @@ func (f *Function) identifierExists(name string) bool {
 }
 
 func (f *Function) storeVariableInRegister(name string, value *expression.Expression, uses int) error {
-	reg, exists := f.cpu.FindFree(f.cpu.General)
+	reg, exists := f.Scope().FindFree(f.cpu.General)
 
 	if !exists {
 		panic("no free registers")
 	}
 
-	f.cpu.Reserve(reg)
+	f.Scope().Reserve(reg)
 	err := f.ExpressionToRegister(value, reg)
 
 	f.AddVariable(&Variable{
@@ -95,15 +101,3 @@ func (f *Function) storeVariableInRegister(name string, value *expression.Expres
 
 	return err
 }
-
-func CountIdentifier(tokens token.List, name string) int {
-	count := 0
-
-	for _, t := range tokens {
-		if t.Kind == token.Identifier && t.Text() == name {
-			count++
-		}
-	}
-
-	return count
-}