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compiler: more precise 'declared and not used' error positioning

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* compiler: extract and cleanup error handling functionality into its own file compiler/compile_errors.v

* compiler: implement p.error_with_token_index and p.warn_with_token_index and use them. Fix tests.

* tools/performance_compare: add a 'Source lines in compiler/' line

* MSVC does not have STDOUT_FILENO nor STDERR_FILENO ...
This commit is contained in:
Delyan Angelov 2019-09-29 20:37:39 +03:00 • committed by Alexander Medvednikov
parent 6d483c0a56
commit e72fe25224
9 changed files with 303 additions and 241 deletions
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113
compiler/scanner.v
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@ -7,7 +7,6 @@ module main
import (
os
strings
term
)
const (
@ -81,72 +80,6 @@ fn new_scanner(text string) &Scanner {
}
// 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 }
}
// TODO remove once multiple return values are implemented
struct ScanRes {
tok Token
@ -652,52 +585,6 @@ fn (s &Scanner) current_column() int {
return s.pos - s.last_nl_pos
}
fn imax(a,b int) int { return if a > b { a } else { b } }
fn imin(a,b int) int { return if a < b { a } else { b } }
fn (s &Scanner) error(msg string) {
s.error_with_col(msg, 0)
}
fn (s &Scanner) error_with_col(msg string, col int) {
fullpath := os.realpath( s.file_path )
color_on := s.should_print_errors_in_color && term.can_show_color()
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 }
println( 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
}
println( ' ' + pointerline.join('') )
}
}
exit(1)
}
fn (s Scanner) count_symbol_before(p int, sym byte) int {
mut count := 0
for i:=p; i>=0; i-- {