compiler: check if mutable receivers are modified

compiler/cgen.v

@@ -120,7 +120,7 @@ fn (g mut CGen) end_tmp() string {
 	return res
 }
 
-fn (g mut CGen) add_placeholder() int {
+fn (g &CGen) add_placeholder() int {
 	if g.is_tmp {
 		return g.tmp_line.len
 	}
@@ -176,7 +176,7 @@ fn (g mut CGen) register_thread_fn(wrapper_name, wrapper_text, struct_text strin
 	g.thread_args << wrapper_text
 }
 
-fn (c mut V) prof_counters() string {
+fn (v &V) prof_counters() string {
 	mut res := []string
 	// Global fns
 	//for f in c.table.fns {
@@ -196,7 +196,7 @@ fn (c mut V) prof_counters() string {
 	return res.join(';\n')
 }
 
-fn (p mut Parser) print_prof_counters() string {
+fn (p &Parser) print_prof_counters() string {
 	mut res := []string
 	// Global fns
 	//for f in p.table.fns {
@@ -296,7 +296,7 @@ fn platform_postfix_to_ifdefguard(name string) string {
 // C struct definitions, ordered
 // Sort the types, make sure types that are referenced by other types
 // are added before them.
-fn (v mut V) type_definitions() string {
+fn (v &V) type_definitions() string {
 	mut types := []Type // structs that need to be sorted
 	mut builtin_types := []Type // builtin types
 	// builtin types need to be on top

compiler/comptime.v

@@ -263,9 +263,6 @@ return strings__Builder_str(sb);
 } '
 }
 
-fn (p mut Parser) parse_t() {
-
-}
 
 
 

compiler/fn.v

@@ -510,7 +510,8 @@ fn (p mut Parser) check_unused_variables() {
 			p.scanner.line_nr = var.line_nr - 1
 			p.error('`$var.name` declared and not used')
 		}
-		if !var.is_changed && var.is_mut && !p.pref.is_repl && !var.is_arg && !p.pref.translated && var.name != '_' {
+	if !var.is_changed && var.is_mut && !p.pref.is_repl &&
+ !p.pref.translated && var.name != '_' {
 			p.scanner.line_nr = var.line_nr - 1
 			p.error('`$var.name` is declared as mutable, but it was never changed')
 		}

compiler/live.v

@@ -2,7 +2,7 @@ module main
 
 import os
 
-fn (v mut V) generate_hotcode_reloading_compiler_flags() []string {
+fn (v &V) generate_hotcode_reloading_compiler_flags() []string {
   mut a := []string
 	if v.pref.is_live || v.pref.is_so {
 		// See 'man dlopen', and test running a GUI program compiled with -live
@@ -16,7 +16,7 @@ fn (v mut V) generate_hotcode_reloading_compiler_flags() []string {
   return a
 }
 
-fn (v mut V) generate_hotcode_reloading_declarations() {
+fn (v &V) generate_hotcode_reloading_declarations() {
   mut cgen := v.cgen
 	if v.os != .windows && v.os != .msvc {
 		if v.pref.is_so {

compiler/parser.v

@@ -770,7 +770,7 @@ if p.scanner.line_comment != '' {
 }
 }
 
-fn (p mut Parser) warn(s string) {
+fn (p &Parser) warn(s string) {
 	println('warning: $p.scanner.file_path:${p.scanner.line_nr+1}: $s')
 }
 

compiler/repl.v

@@ -41,7 +41,7 @@ fn (r mut Repl) checks(line string) bool {
 	return r.in_func || (was_indent && r.indent <= 0) || r.indent > 0
 }
 
-fn (r mut Repl) function_call(line string) bool {
+fn (r &Repl) function_call(line string) bool {
 	for function in r.functions_name {
 		if line.starts_with(function) {
 			return true

compiler/scanner.v

@@ -752,6 +752,9 @@ fn (s mut Scanner) ident_char() string {
 			s.error('invalid character literal (more than one character: $len)')
 		}
 	}
+	if c == '\\`' {
+		return '`'
+	}	
 	// Escapes a `'` character
 	return if c == '\'' { '\\' + c } else { c }
 }
@@ -776,7 +779,7 @@ fn (s mut Scanner) peek() Token {
 	return tok
 }
 
-fn (s mut Scanner) expect(want string, start_pos int) bool {
+fn (s &Scanner) expect(want string, start_pos int) bool {
 	end_pos := start_pos + want.len
 	if start_pos < 0 || start_pos >= s.text.len {
 		return false
@@ -825,7 +828,7 @@ fn is_nl(c byte) bool {
 	return c == `\r` || c == `\n`
 }
 
-fn (s mut Scanner) get_opening_bracket() int {
+fn (s &Scanner) get_opening_bracket() int {
 	mut pos := s.pos
 	mut parentheses := 0
 	mut inside_string := false

compiler/table.v

@@ -236,7 +236,7 @@ fn new_table(obfuscate bool) &Table {
 }
 
 // If `name` is a reserved C keyword, returns `v_name` instead.
-fn (t mut Table) var_cgen_name(name string) string {
+fn (t &Table) var_cgen_name(name string) string {
 	if name in CReserved {
 		return 'v_$name'
 	}
@@ -707,7 +707,7 @@ fn (t mut Table) register_generic_fn(fn_name string) {
 	t.generic_fns << GenTable{fn_name, []string}
 }
 
-fn (t mut Table) fn_gen_types(fn_name string) []string {
+fn (t &Table) fn_gen_types(fn_name string) []string {
 	for _, f in t.generic_fns {
 		if f.fn_name == fn_name {
 			return f.types

vlib/builtin/array_test.v

@@ -166,7 +166,6 @@ const (
 )
 
 fn test_fixed() {
-	/*
 	mut nums := [4]int
 	assert nums[0] == 0
 	assert nums[1] == 0
@@ -177,7 +176,6 @@ fn test_fixed() {
 	///////
 	nums2 := [N]int
 	assert nums2[N - 1] == 0
-	*/
 }
 
 fn modify (numbers mut []int) {