v/compiler/compile_errors.v

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module main
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 := os.realpath( s.file_path )
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}: $final_message')
}
fn (s &Scanner) error_with_col(msg string, col int) {
fullpath := os.realpath( s.file_path )
color_on := s.is_color_output_on()
final_message := if color_on { term.red( term.bold( msg ) ) } else { msg }
// The filepath:line:col: format is the default C compiler
// error output format. It allows editors and IDE's like
// emacs to quickly find the errors in the output
// and jump to their source with a keyboard shortcut.
// Using only the filename leads to inability of IDE/editors
// to find the source file, when it is in another folder.
eprintln('${fullpath}:${s.line_nr + 1}:${col}: $final_message')
if s.should_print_line_on_error && s.file_lines.len > 0 {
context_start_line := imax(0, (s.line_nr - error_context_before + 1 ))
context_end_line := imin(s.file_lines.len, (s.line_nr + error_context_after + 1 ))
for cline := context_start_line; cline < context_end_line; cline++ {
line := '${(cline+1):5d}| ' + s.file_lines[ 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) 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 &Tok) 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. Continue scanning for some more lines of context too.
s.goto_scanner_position(ScannerPos{})
s.file_lines = []string
mut prevlinepos := 0
for {
prevlinepos = s.pos
if s.pos >= s.text.len { break }
if s.line_nr > tline + 10 { break }
////////////////////////////////////////
if tline == s.line_nr {
sptoken = s.get_scanner_pos()
sptoken.pos += tcol
}
s.ignore_line() s.eat_single_newline()
sline := s.text.substr( prevlinepos, s.pos ).trim_right('\r\n')
s.file_lines << sline
}
//////////////////////////////////////////////////
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 }
}