all: support -N, turning *all* notices into errors, to ease the process of finding places that may need attention/correction

vlib/v/checker/checker.v

@@ -4568,6 +4568,9 @@ fn (mut c Checker) note(message string, pos token.Pos) {
 	if c.is_generated {
 		return
 	}
+	if c.pref.notes_are_errors {
+		c.error(message, pos)
+	}
 	mut details := ''
 	if c.error_details.len > 0 {
 		details = c.error_details.join('\n')

vlib/v/parser/parser.v

@@ -2061,6 +2061,10 @@ fn (mut p Parser) note_with_pos(s string, pos token.Pos) {
 	if p.is_generated {
 		return
 	}
+	if p.pref.notes_are_errors {
+		p.error_with_pos(s, pos)
+		return
+	}
 	if p.pref.output_mode == .stdout && !p.pref.check_only {
 		util.show_compiler_message('notice:', pos: pos, file_path: p.file_name, message: s)
 	} else {

vlib/v/pref/pref.v

@@ -206,6 +206,7 @@ pub mut:
 	skip_warnings    bool // like C's "-w", forces warnings to be ignored.
 	warn_impure_v    bool // -Wimpure-v, force a warning for JS.fn()/C.fn(), outside of .js.v/.c.v files. TODO: turn to an error by default
 	warns_are_errors bool // -W, like C's "-Werror", treat *every* warning is an error
+	notes_are_errors bool // -N, treat *every* notice as an error
 	fatal_errors     bool // unconditionally exit after the first error with exit(1)
 	reuse_tmpc       bool // do not use random names for .tmp.c and .tmp.c.rsp files, and do not remove them
 	no_rsp           bool // when true, pass C backend options directly on the CLI (do not use `.rsp` files for them, some older C compilers do not support them)
@@ -665,6 +666,9 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 			'-W' {
 				res.warns_are_errors = true
 			}
+			'-N' {
+				res.notes_are_errors = true
+			}
 			'-no-rsp' {
 				res.no_rsp = true
 			}

vlib/v/scanner/scanner.v

@@ -1578,7 +1578,19 @@ fn (mut s Scanner) inc_line_number() {
 	}
 }
 
+pub fn (mut s Scanner) current_pos() token.Pos {
+	return token.Pos{
+		line_nr: s.line_nr
+		pos: s.pos
+		col: s.current_column() - 1
+	}
+}
+
 pub fn (mut s Scanner) note(msg string) {
+	if s.pref.notes_are_errors {
+		s.error_with_pos(msg, s.current_pos())
+		return
+	}
 	pos := token.Pos{
 		line_nr: s.line_nr
 		pos: s.pos
@@ -1614,12 +1626,7 @@ fn (mut s Scanner) eat_details() string {
 }
 
 pub fn (mut s Scanner) warn(msg string) {
-	pos := token.Pos{
-		line_nr: s.line_nr
-		pos: s.pos
-		col: s.current_column() - 1
-	}
-	s.warn_with_pos(msg, pos)
+	s.warn_with_pos(msg, s.current_pos())
 }
 
 pub fn (mut s Scanner) warn_with_pos(msg string, pos token.Pos) {
@@ -1651,12 +1658,7 @@ pub fn (mut s Scanner) warn_with_pos(msg string, pos token.Pos) {
 }
 
 pub fn (mut s Scanner) error(msg string) {
-	pos := token.Pos{
-		line_nr: s.line_nr
-		pos: s.pos
-		col: s.current_column() - 1
-	}
-	s.error_with_pos(msg, pos)
+	s.error_with_pos(msg, s.current_pos())
 }
 
 pub fn (mut s Scanner) error_with_pos(msg string, pos token.Pos) {
@@ -1697,10 +1699,7 @@ fn (mut s Scanner) vet_error(msg string, fix vet.FixKind) {
 	ve := vet.Error{
 		message: msg
 		file_path: s.file_path
-		pos: token.Pos{
-			line_nr: s.line_nr
-			col: s.current_column() - 1
-		}
+		pos: s.current_pos()
 		kind: .error
 		fix: fix
 		typ: .default