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v/vlib/compiler/compile_errors.v
2019-11-11 04:56:13 +03:00

299 lines
10 KiB
V

module compiler
import (
os
term
)
//////////////////////////////////////////////////////////////////////////////////////////////////
// NB: The code in this file is organized in layers (between the ///// lines).
// This allows for easier keeping in sync of error/warn functions.
// The functions in each of the layers, call the functions from the layers *below*.
// The functions in each of the layers, also have more details about the warn/error situation,
// so they can display more informative message, so please call the lowest level variant you can.
//////////////////////////////////////////////////////////////////////////////////////////////////
// TLDR: If you have a token index, call:
// p.error_with_token_index(msg, token_index)
// ... not just :
// p.error(msg)
//////////////////////////////////////////////////////////////////////////////////////////////////
fn (p mut Parser) error(s string) {
// no positioning info, so just assume that the last token was the culprit:
p.error_with_token_index(s, p.token_idx-1 )
}
fn (p mut Parser) warn(s string) {
p.warn_with_token_index(s, p.token_idx-1 )
}
fn (p mut Parser) production_error_with_token_index(e string, tokenindex int) {
if p.pref.is_prod {
p.error_with_token_index( e, tokenindex )
}else {
p.warn_with_token_index( e, tokenindex )
}
}
fn (p mut Parser) error_with_token_index(s string, tokenindex int) {
p.error_with_position(s, p.scanner.get_scanner_pos_of_token( p.tokens[ tokenindex ] ) )
}
fn (p mut Parser) warn_with_token_index(s string, tokenindex int) {
p.warn_with_position(s, p.scanner.get_scanner_pos_of_token( p.tokens[ tokenindex ] ) )
}
fn (p mut Parser) error_with_position(s string, sp ScannerPos) {
p.print_error_context()
e := normalized_error( s )
p.scanner.goto_scanner_position( sp )
p.scanner.error_with_col(e, sp.pos - sp.last_nl_pos)
}
fn (p mut Parser) warn_with_position(s string, sp ScannerPos) {
// on a warning, restore the scanner state after printing the warning:
cpos := p.scanner.get_scanner_pos()
e := normalized_error( s )
p.scanner.goto_scanner_position( sp )
p.scanner.warn_with_col(e, sp.pos - sp.last_nl_pos)
p.scanner.goto_scanner_position( cpos )
}
fn (s &Scanner) error(msg string) {
s.error_with_col(msg, 0)
}
fn (s &Scanner) warn(msg string) {
s.warn_with_col(msg, 0)
}
fn (s &Scanner) warn_with_col(msg string, col int) {
fullpath := s.get_error_filepath()
color_on := s.is_color_output_on()
final_message := if color_on { term.bold(term.bright_blue( msg )) } else { msg }
eprintln('warning: ${fullpath}:${s.line_nr+1}:${col}: $final_message')
}
fn (s &Scanner) error_with_col(msg string, col int) {
fullpath := s.get_error_filepath()
color_on := s.is_color_output_on()
final_message := if color_on { term.red( term.bold( msg ) ) } else { msg }
// The filepath:line:col: format is the default C compiler
// error output format. It allows editors and IDE's like
// emacs to quickly find the errors in the output
// and jump to their source with a keyboard shortcut.
// NB: using only the filename may lead to inability of IDE/editors
// to find the source file, when the IDE has a different working folder than v itself.
eprintln('${fullpath}:${s.line_nr + 1}:${col}: $final_message')
if s.should_print_line_on_error && s.nlines > 0 {
context_start_line := imax(0, (s.line_nr - error_context_before ))
context_end_line := imin(s.nlines-1, (s.line_nr + error_context_after + 1 ))
for cline := context_start_line; cline < context_end_line; cline++ {
line := '${(cline+1):5d}| ' + s.line( cline )
coloredline := if cline == s.line_nr && color_on { term.red(line) } else { line }
eprintln( coloredline )
if cline != s.line_nr { continue }
// The pointerline should have the same spaces/tabs as the offending
// line, so that it prints the ^ character exactly on the *same spot*
// where it is needed. That is the reason we can not just
// use strings.repeat(` `, col) to form it.
mut pointerline := []string
for i , c in line {
if i < col {
x := if c.is_space() { c } else { ` ` }
pointerline << x.str()
continue
}
pointerline << if color_on { term.bold( term.blue('^') ) } else { '^' }
break
}
eprintln( ' ' + pointerline.join('') )
}
}
exit(1)
}
//////////////////////////////////////////////////////////////////////////////////////////////////
/// Misc error helper functions, can be called by any of the functions above
[inline] fn (p &Parser) cur_tok_index() int { return p.token_idx - 1 }
[inline] fn imax(a,b int) int { return if a > b { a } else { b } }
[inline] fn imin(a,b int) int { return if a < b { a } else { b } }
fn (s &Scanner) get_error_filepath() string {
verror_paths_override := os.getenv('VERROR_PATHS')
use_relative_paths := match verror_paths_override {
'relative' { true }
'absolute' { false }
else { s.should_print_relative_paths_on_error }
}
if use_relative_paths {
workdir := os.getwd() + os.path_separator
if s.file_path.starts_with(workdir) {
return s.file_path.replace( workdir, '')
}
return s.file_path
}
return os.realpath( s.file_path )
}
fn (s &Scanner) is_color_output_on() bool {
return s.should_print_errors_in_color && term.can_show_color_on_stderr()
}
fn (p mut Parser) print_error_context(){
// Dump all vars and types for debugging
if p.pref.is_debug {
// os.write_to_file('/var/tmp/lang.types', '')//pes(p.table.types))
os.write_file('fns.txt', p.table.debug_fns())
}
if p.pref.is_verbose || p.pref.is_debug {
println('pass=$p.pass fn=`$p.cur_fn.name`\n')
}
p.cgen.save()
// V up hint
cur_path := os.getwd()
if !p.pref.is_repl && !p.pref.is_test && ( p.file_path.contains('v/compiler') || cur_path.contains('v/compiler') ){
println('\n=========================')
println('It looks like you are building V. It is being frequently updated every day.')
println('If you didn\'t modify V\'s code, most likely there was a change that ')
println('lead to this error.')
println('\nRun `v up`, that will most likely fix it.')
//println('\nIf this doesn\'t help, re-install V from source or download a precompiled' + ' binary from\nhttps://vlang.io.')
println('\nIf this doesn\'t help, please create a GitHub issue.')
println('=========================\n')
}
if p.pref.is_debug {
print_backtrace()
}
// p.scanner.debug_tokens()
}
fn normalized_error( s string ) string {
// Print `[]int` instead of `array_int` in errors
return s.replace('array_', '[]')
.replace('__', '.')
.replace('Option_', '?')
.replace('main.', '')
}
//////////////////////////////////////////////////////////////////////////////////////////////////
// The goal of ScannerPos is to track the current scanning position,
// so that if there is an error found later, v could show a more accurate
// position about where the error initially was.
// NB: The fields of ScannerPos *should be kept synchronized* with the
// corresponding fields in Scanner.
struct ScannerPos {
mut:
pos int
line_nr int
last_nl_pos int
}
fn (s ScannerPos) str() string {
return 'ScannerPos{ ${s.pos:5d} , ${s.line_nr:5d} , ${s.last_nl_pos:5d} }'
}
fn (s &Scanner) get_scanner_pos() ScannerPos {
return ScannerPos{ pos: s.pos line_nr: s.line_nr last_nl_pos: s.last_nl_pos }
}
fn (s mut Scanner) goto_scanner_position(scp ScannerPos) {
s.pos = scp.pos
s.line_nr = scp.line_nr
s.last_nl_pos = scp.last_nl_pos
}
// get_scanner_pos_of_token rescans *the whole source* till it reaches {t.line_nr, t.col} .
fn (s mut Scanner) get_scanner_pos_of_token(t &Token) ScannerPos {
// This rescanning is done just once on error, so it is fine for now.
// Be careful for the performance implications, if you want to
// do it more frequently. The alternative would be to store
// the scanpos (12 bytes) for each token, and there are potentially many tokens.
tline := t.line_nr
tcol := if t.line_nr == 0 { t.col + 1 } else { t.col - 1 }
// save the current scanner position, it will be restored later
cpos := s.get_scanner_pos()
mut sptoken := ScannerPos{}
// Starting from the start, scan the source lines
// till the desired tline is reached, then
// s.pos + tcol would be the proper position
// of the token.
s.goto_scanner_position(ScannerPos{})
mut prevlinepos := 0
// NB: TCC BUG workaround: removing the `mut ate:=0 ate++` line
// below causes a bug in v, when v is compiled with tcc, and v
// wants to report the error: 'the following imports were never used:'
//
// This can be reproduced, if you follow the steps:
// a) ./v -cc tcc -o v compiler ;
// b) ./v vlib/builtin/hashmap_test.v'
//
// In this case, prevlinepos gets a random value on each run.
// Any kind of operation may be used seemingly, as long as
// there is a new stack allocation that will 'protect' prevlinepos.
//////////////////////////////////////////////////////////////////
mut ate:=0 ate++ // This var will be smashed by TCC, instead of
/////////////////// prevlinepos. The cause is the call to
/////////////////// s.get_scanner_pos()
/////////////////// which just returns a struct, and that works
/////////////////// in gcc and clang, but causes the TCC problem.
maxline := imin( s.nlines, tline + 2 * error_context_after)
for {
prevlinepos = s.pos
if s.pos >= s.text.len { break }
if s.line_nr > maxline { break }
////////////////////////////////////////
if tline == s.line_nr {
sptoken = s.get_scanner_pos()
sptoken.pos += tcol
}
s.ignore_line() s.eat_single_newline()
}
//////////////////////////////////////////////////
s.goto_scanner_position(cpos)
return sptoken
}
fn (s mut Scanner) eat_single_newline(){
if s.pos >= s.text.len { return }
if s.expect('\r\n', s.pos) { s.pos += 2 return }
if s.text[ s.pos ] == `\n` { s.pos ++ return }
if s.text[ s.pos ] == `\r` { s.pos ++ return }
}
///////////////////////////////
fn (p mut Parser) mutable_arg_error(i int, arg Var, f Fn) {
mut dots_example := 'mut $p.lit'
if i > 0 {
dots_example = '.., ' + dots_example
}
if i < f.args.len - 1 {
dots_example = dots_example + ',..'
}
p.error('`$arg.name` is a mutable argument, you need to provide `mut`: ' +
'`$f.name($dots_example)`')
}
const (
warn_match_arrow = '=> is no longer needed in match statements, use\n' +
'match foo {
1 { bar }
2 { baz }
else { ... }
}'
//make_receiver_mutable =
err_used_as_value = 'used as value'
and_or_error = 'use `()` to make the boolean expression clear\n' +
'for example: `(a && b) || c` instead of `a && b || c`'
)