diff --git a/vlib/os/process_nix.c.v b/vlib/os/process_nix.c.v
index 150e0c830d1e1f..72806ad5956f98 100644
--- a/vlib/os/process_nix.c.v
+++ b/vlib/os/process_nix.c.v
@@ -147,13 +147,13 @@ fn (mut p Process) win_is_alive() bool {
 	return false
 }
 
-fn (mut p Process) win_write_string(idx int, s string) {
+fn (mut p Process) win_write_string(_idx int, _s string) {
 }
 
-fn (mut p Process) win_read_string(idx int, maxbytes int) (string, int) {
+fn (mut p Process) win_read_string(_idx int, _maxbytes int) (string, int) {
 	return '', 0
 }
 
-fn (mut p Process) win_slurp(idx int) string {
+fn (mut p Process) win_slurp(_idx int) string {
 	return ''
 }
diff --git a/vlib/os/process_windows.c.v b/vlib/os/process_windows.c.v
index f55cb09e395b3e..8cb003b2ff16dc 100644
--- a/vlib/os/process_windows.c.v
+++ b/vlib/os/process_windows.c.v
@@ -197,11 +197,11 @@ fn (mut p Process) win_is_alive() bool {
 
 ///////////////
 
-fn (mut p Process) win_write_string(idx int, s string) {
+fn (mut p Process) win_write_string(idx int, _s string) {
 	panic('Process.write_string ${idx} is not implemented yet')
 }
 
-fn (mut p Process) win_read_string(idx int, maxbytes int) (string, int) {
+fn (mut p Process) win_read_string(idx int, _maxbytes int) (string, int) {
 	mut wdata := unsafe { &WProcess(p.wdata) }
 	if unsafe { wdata == 0 } {
 		return '', 0
diff --git a/vlib/os/signal.c.v b/vlib/os/signal.c.v
index 3278489e069030..286cb6654f24ee 100644
--- a/vlib/os/signal.c.v
+++ b/vlib/os/signal.c.v
@@ -21,7 +21,7 @@ pub fn signal_opt(signum Signal, handler SignalHandler) !SignalHandler {
 // So a global variable is introduced to make the distinction.
 
 // An empty system signal handler (callback function) used to mask the specified system signal.
-fn ignore_signal_handler(signal Signal) {
+fn ignore_signal_handler(_signal Signal) {
 }
 
 // signal_ignore to mask system signals, e.g.: signal_ignore(.pipe, .urg, ...)
diff --git a/vlib/os/signal_windows.c.v b/vlib/os/signal_windows.c.v
index 9d9603d1bec87b..d3049ee2583da1 100644
--- a/vlib/os/signal_windows.c.v
+++ b/vlib/os/signal_windows.c.v
@@ -14,5 +14,5 @@ pub fn is_main_thread() bool {
 }
 
 // The windows platform does not need to be handled.
-fn signal_ignore_internal(args ...Signal) {
+fn signal_ignore_internal(_args ...Signal) {
 }
diff --git a/vlib/sync/pool/pool.c.v b/vlib/sync/pool/pool.c.v
index 5958daa2f4af2f..0d4562fd267a69 100644
--- a/vlib/sync/pool/pool.c.v
+++ b/vlib/sync/pool/pool.c.v
@@ -22,7 +22,7 @@ mut:
 
 pub type ThreadCB = fn (mut p PoolProcessor, idx int, task_id int) voidptr
 
-fn empty_cb(mut p PoolProcessor, idx int, task_id int) voidptr {
+fn empty_cb(mut _p PoolProcessor, _idx int, _task_id int) voidptr {
 	unsafe {
 		return nil
 	}
diff --git a/vlib/v/ast/table.v b/vlib/v/ast/table.v
index ed94ea826c87cb..eea4f99582722a 100644
--- a/vlib/v/ast/table.v
+++ b/vlib/v/ast/table.v
@@ -106,7 +106,7 @@ pub const map_cname_escape_seq = ['[', '_T_', ', ', '_', ']', '']
 
 pub type FnPanicHandler = fn (&Table, string)
 
-fn default_table_panic_handler(t &Table, message string) {
+fn default_table_panic_handler(_t &Table, message string) {
 	panic(message)
 }
 
diff --git a/vlib/v/ast/walker/walker.v b/vlib/v/ast/walker/walker.v
index 93e3aff2953460..f55382eaebd5de 100644
--- a/vlib/v/ast/walker/walker.v
+++ b/vlib/v/ast/walker/walker.v
@@ -11,7 +11,7 @@ mut:
 pub type InspectorFn = fn (node &ast.Node, data voidptr) bool
 
 fn empty_callback(node &ast.Node, data voidptr) bool {
-	panic('empty ast.walker')
+	panic('empty ast.walker, node: ${voidptr(node)}, data: ${voidptr(data)}')
 }
 
 struct Inspector {
diff --git a/vlib/v/builder/cbuilder/parallel_cc.v b/vlib/v/builder/cbuilder/parallel_cc.v
index 271522783ef247..264b8b37d37e15 100644
--- a/vlib/v/builder/cbuilder/parallel_cc.v
+++ b/vlib/v/builder/cbuilder/parallel_cc.v
@@ -6,7 +6,7 @@ import v.util
 import v.builder
 import sync.pool
 
-fn parallel_cc(mut b builder.Builder, header string, res string, out_str string, out_fn_start_pos []int) {
+fn parallel_cc(mut b builder.Builder, header string, _res string, out_str string, out_fn_start_pos []int) {
 	c_files := util.nr_jobs
 	println('> c_files: ${c_files} | util.nr_jobs: ${util.nr_jobs}')
 	out_h := header.replace_once('static char * v_typeof_interface_IError', 'char * v_typeof_interface_IError')
@@ -67,7 +67,7 @@ fn parallel_cc(mut b builder.Builder, header string, res string, out_str string,
 	eprint_time('link_cmd', link_cmd, link_res, sw_link)
 }
 
-fn build_parallel_o_cb(mut p pool.PoolProcessor, idx int, wid int) voidptr {
+fn build_parallel_o_cb(mut p pool.PoolProcessor, idx int, _wid int) voidptr {
 	postfix := p.get_item[string](idx)
 	sw := time.new_stopwatch()
 	cmd := '${os.quoted_path(cc_compiler)} ${cc_cflags} -c -w -o out_${postfix}.o out_${postfix}.c'
diff --git a/vlib/v/builder/msvc_windows.v b/vlib/v/builder/msvc_windows.v
index 8b1dda0570ba6f..77e687d8491ca1 100644
--- a/vlib/v/builder/msvc_windows.v
+++ b/vlib/v/builder/msvc_windows.v
@@ -386,7 +386,7 @@ pub fn (mut v Builder) cc_msvc() {
 	// println('C OUTPUT:')
 }
 
-fn (mut v Builder) build_thirdparty_obj_file_with_msvc(mod string, path string, moduleflags []cflag.CFlag) {
+fn (mut v Builder) build_thirdparty_obj_file_with_msvc(_mod string, path string, moduleflags []cflag.CFlag) {
 	msvc := v.cached_msvc
 	if msvc.valid == false {
 		verror('cannot find MSVC on this OS')
diff --git a/vlib/v/checker/orm.v b/vlib/v/checker/orm.v
index 06b6f44fceae14..358a854ca73540 100644
--- a/vlib/v/checker/orm.v
+++ b/vlib/v/checker/orm.v
@@ -36,8 +36,7 @@ fn (mut c Checker) sql_expr(mut node ast.SqlExpr) ast.Type {
 	}
 
 	info := table_sym.info as ast.Struct
-	mut fields := c.fetch_and_check_orm_fields(info, node.table_expr.pos, table_sym.name,
-		node)
+	mut fields := c.fetch_and_check_orm_fields(info, node.table_expr.pos, table_sym.name)
 	non_primitive_fields := c.get_orm_non_primitive_fields(fields)
 	mut sub_structs := map[int]ast.SqlExpr{}
 
@@ -269,8 +268,7 @@ fn (mut c Checker) sql_stmt_line(mut node ast.SqlStmtLine) ast.Type {
 	}
 
 	info := table_sym.info as ast.Struct
-	mut fields := c.fetch_and_check_orm_fields(info, node.table_expr.pos, table_sym.name,
-		ast.SqlExpr{})
+	mut fields := c.fetch_and_check_orm_fields(info, node.table_expr.pos, table_sym.name)
 
 	for field in fields {
 		c.check_orm_struct_field_attrs(node, field)
@@ -397,7 +395,7 @@ fn (mut c Checker) check_orm_non_primitive_struct_field_attrs(field ast.StructFi
 	}
 }
 
-fn (mut c Checker) fetch_and_check_orm_fields(info ast.Struct, pos token.Pos, table_name string, sql_expr ast.SqlExpr) []ast.StructField {
+fn (mut c Checker) fetch_and_check_orm_fields(info ast.Struct, pos token.Pos, table_name string) []ast.StructField {
 	if cache := c.orm_table_fields[table_name] {
 		return cache
 	}
diff --git a/vlib/v/gen/c/array.v b/vlib/v/gen/c/array.v
index f8dabfc1e9a884..4eff6bc9a2dc6a 100644
--- a/vlib/v/gen/c/array.v
+++ b/vlib/v/gen/c/array.v
@@ -158,7 +158,7 @@ fn (mut g Gen) fixed_array_init(node ast.ArrayInit, array_type Type, var_name st
 			} else if elem_sym.kind == .array_fixed && expr is ast.CallExpr
 				&& g.table.final_sym(expr.return_type).kind == .array_fixed {
 				elem_info := elem_sym.array_fixed_info()
-				tmp_var := g.expr_with_var(expr, node.expr_types[i], node.expr_types[i])
+				tmp_var := g.expr_with_var(expr, node.expr_types[i])
 				g.fixed_array_var_init(tmp_var, false, elem_info.elem_type, elem_info.size)
 			} else {
 				if expr.is_auto_deref_var() {
diff --git a/vlib/v/gen/c/assign.v b/vlib/v/gen/c/assign.v
index a9b32eef5de567..80fb746ab49684 100644
--- a/vlib/v/gen/c/assign.v
+++ b/vlib/v/gen/c/assign.v
@@ -195,7 +195,7 @@ fn (mut g Gen) assign_stmt(node_ ast.AssignStmt) {
 			af = false
 		}
 	}
-	g.gen_assign_vars_autofree(node)
+	// TODO: g.gen_assign_vars_autofree(node)
 	// json_test failed w/o this check
 	if return_type != ast.void_type && return_type != 0 {
 		sym := g.table.sym(return_type)
@@ -959,48 +959,6 @@ fn (mut g Gen) gen_multi_return_assign(node &ast.AssignStmt, return_type ast.Typ
 	}
 }
 
-fn (mut g Gen) gen_assign_vars_autofree(node &ast.AssignStmt) {
-	// Autofree tmp arg vars
-	// first_right := node.right[0]
-	// af := g.autofree && first_right is ast.CallExpr && !g.is_builtin_mod
-	// if af {
-	// g.autofree_call_pregen(first_right as ast.CallExpr)
-	// }
-	//
-	//
-	// Handle options. We need to declare a temp variable for them, that's why they are handled
-	// here, not in call_expr().
-	// `pos := s.index('x') or { return }`
-	// ==========>
-	// Option_int _t190 = string_index(s, _STR("x")); // _STR() no more used!!
-	// if (_t190.state != 2) {
-	// Error err = _t190.err;
-	// return;
-	// }
-	// int pos = *(int*)_t190.data;
-	// mut tmp_opt := ''
-	/*
-	is_option := false && g.is_autofree && (node.op in [.decl_assign, .assign])
-		&& node.left_types.len == 1 && node.right[0] is ast.CallExpr
-	if is_option {
-		// g.write('/* option assignment */')
-		call_expr := node.right[0] as ast.CallExpr
-		if call_expr.or_block.kind != .absent {
-			styp := g.styp(call_expr.return_type.set_flag(.option))
-			tmp_opt = g.new_tmp_var()
-			g.write('/*AF opt*/$styp $tmp_opt = ')
-			g.expr(node.right[0])
-			g.or_block(tmp_opt, call_expr.or_block, call_expr.return_type)
-			g.writeln('/*=============ret*/')
-			// if af && is_option {
-			// g.autofree_call_postgen()
-			// }
-			// return
-		}
-	}
-	*/
-}
-
 fn (mut g Gen) gen_cross_var_assign(node &ast.AssignStmt) {
 	for i, left in node.left {
 		left_is_auto_deref_var := left.is_auto_deref_var()
diff --git a/vlib/v/gen/c/auto_free_methods.v b/vlib/v/gen/c/auto_free_methods.v
index b1c2fc81deab74..eca80bd4f11c36 100644
--- a/vlib/v/gen/c/auto_free_methods.v
+++ b/vlib/v/gen/c/auto_free_methods.v
@@ -68,7 +68,7 @@ fn (mut g Gen) gen_free_method(typ ast.Type) string {
 			g.gen_free_for_array(sym.info, styp, fn_name)
 		}
 		ast.Map {
-			g.gen_free_for_map(objtyp, sym.info, styp, fn_name)
+			g.gen_free_for_map(objtyp, styp, fn_name)
 		}
 		ast.Interface {
 			g.gen_free_for_interface(sym, sym.info, styp, fn_name)
@@ -200,7 +200,7 @@ fn (mut g Gen) gen_free_for_array(info ast.Array, styp string, fn_name string) {
 	fn_builder.writeln('}')
 }
 
-fn (mut g Gen) gen_free_for_map(typ ast.Type, info ast.Map, styp string, fn_name string) {
+fn (mut g Gen) gen_free_for_map(typ ast.Type, styp string, fn_name string) {
 	g.definitions.writeln('${g.static_modifier} void ${fn_name}(${styp}* it); // auto')
 	mut fn_builder := strings.new_builder(128)
 	defer {
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index f01dd7358a2aa4..d5c90c9f6bc0a0 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -2554,7 +2554,7 @@ fn (mut g Gen) call_cfn_for_casting_expr(fname string, expr ast.Expr, exp_is_ptr
 }
 
 // use instead of expr() when you need a var to use as reference
-fn (mut g Gen) expr_with_var(expr ast.Expr, got_type_raw ast.Type, expected_type ast.Type) string {
+fn (mut g Gen) expr_with_var(expr ast.Expr, expected_type ast.Type) string {
 	stmt_str := g.go_before_last_stmt().trim_space()
 	g.empty_line = true
 	tmp_var := g.new_tmp_var()
@@ -3201,8 +3201,7 @@ fn (mut g Gen) autofree_scope_vars2(scope &ast.Scope, start_pos int, end_pos int
 					// Do not free vars that were declared after this scope
 					continue
 				}
-				is_option := obj.typ.has_flag(.option)
-				g.autofree_variable(obj, is_option)
+				g.autofree_variable(obj)
 			}
 			else {}
 		}
@@ -3226,7 +3225,7 @@ fn (mut g Gen) autofree_scope_vars2(scope &ast.Scope, start_pos int, end_pos int
 	}
 }
 
-fn (mut g Gen) autofree_variable(v ast.Var, is_option bool) {
+fn (mut g Gen) autofree_variable(v ast.Var) {
 	// filter out invalid variables
 	if v.typ == 0 {
 		return
diff --git a/vlib/v/gen/c/fn.v b/vlib/v/gen/c/fn.v
index 6616a8f6cd6989..7a405f10827b42 100644
--- a/vlib/v/gen/c/fn.v
+++ b/vlib/v/gen/c/fn.v
@@ -1223,7 +1223,7 @@ fn (mut g Gen) gen_array_method_call(node ast.CallExpr, left_type ast.Type, left
 	return true
 }
 
-fn (mut g Gen) gen_fixed_array_method_call(node ast.CallExpr, left_type ast.Type, left_sym ast.TypeSymbol) bool {
+fn (mut g Gen) gen_fixed_array_method_call(node ast.CallExpr, left_type ast.Type) bool {
 	match node.name {
 		'index' {
 			g.gen_array_index(node)
@@ -1773,7 +1773,7 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 	}
 	if final_left_sym.kind == .array_fixed && !(left_sym.kind == .alias
 		&& left_sym.has_method(node.name)) {
-		if g.gen_fixed_array_method_call(node, left_type, final_left_sym) {
+		if g.gen_fixed_array_method_call(node, left_type) {
 			return
 		}
 	}
@@ -2504,11 +2504,6 @@ fn (mut g Gen) autofree_call_postgen(node_pos int) {
 	for _, mut obj in scope.objects {
 		match mut obj {
 			ast.Var {
-				// if var.typ == 0 {
-				// // TODO: why 0?
-				// continue
-				// }
-				is_option := obj.typ.has_flag(.option)
 				is_result := obj.typ.has_flag(.result)
 				if is_result {
 					// TODO: free results
@@ -2522,7 +2517,7 @@ fn (mut g Gen) autofree_call_postgen(node_pos int) {
 					continue
 				}
 				obj.is_used = true // TODO: bug? sets all vars is_used to true
-				g.autofree_variable(obj, is_option)
+				g.autofree_variable(obj)
 				// g.nr_vars_to_free--
 			}
 			else {}
diff --git a/vlib/v/gen/c/struct.v b/vlib/v/gen/c/struct.v
index 97ee42d04b2bbb..d85666c7baa9e1 100644
--- a/vlib/v/gen/c/struct.v
+++ b/vlib/v/gen/c/struct.v
@@ -688,13 +688,13 @@ fn (mut g Gen) struct_init_field(sfield ast.StructInitField, language ast.Langua
 						field_unwrap_sym.info.elem_type, field_unwrap_sym.info.size)
 				}
 				ast.CallExpr {
-					tmp_var := g.expr_with_var(sfield.expr, sfield.typ, sfield.expected_type)
+					tmp_var := g.expr_with_var(sfield.expr, sfield.expected_type)
 					g.fixed_array_var_init(tmp_var, false, field_unwrap_sym.info.elem_type,
 						field_unwrap_sym.info.size)
 				}
 				ast.ArrayInit {
 					if sfield.expr.has_index {
-						tmp_var := g.expr_with_var(sfield.expr, sfield.typ, sfield.expected_type)
+						tmp_var := g.expr_with_var(sfield.expr, sfield.expected_type)
 						g.fixed_array_var_init(tmp_var, false, field_unwrap_sym.info.elem_type,
 							field_unwrap_sym.info.size)
 					} else if sfield.expr.has_callexpr {
diff --git a/vlib/v/vmod/vmod.v b/vlib/v/vmod/vmod.v
index f62e8a8e5caec7..e8c7a652823ce3 100644
--- a/vlib/v/vmod/vmod.v
+++ b/vlib/v/vmod/vmod.v
@@ -115,7 +115,7 @@ fn (mut mcache ModFileCacher) traverse(mfolder string) ([]string, ModFileAndFold
 			}
 			return folders_so_far, res
 		}
-		if mcache.check_for_stop(cfolder, files) {
+		if mcache.check_for_stop(files) {
 			break
 		}
 		cfolder = os.dir(cfolder)
@@ -143,7 +143,7 @@ fn (mut mcache ModFileCacher) mark_folders_as_vmod_free(folders_so_far []string)
 	}
 }
 
-fn (mcache &ModFileCacher) check_for_stop(cfolder string, files []string) bool {
+fn (mcache &ModFileCacher) check_for_stop(files []string) bool {
 	for i in mod_file_stop_paths {
 		if i in files {
 			return true