1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 pub use self::Level::*;
12 pub use self::RenderSpan::*;
13 pub use self::ColorConfig::*;
14 use self::Destination::*;
16 use codemap::{COMMAND_LINE_SP, COMMAND_LINE_EXPN, Pos, Span};
20 use std::cell::{RefCell, Cell};
24 use std::string::String;
25 use term::WriterWrapper;
28 /// maximum number of lines we will print for each error; arbitrary.
29 static MAX_LINES: usize = 6us;
31 #[derive(Clone, Copy)]
33 /// A FullSpan renders with both with an initial line for the
34 /// message, prefixed by file:linenum, followed by a summary of
35 /// the source code covered by the span.
38 /// A FileLine renders with just a line for the message prefixed
44 fn span(self) -> Span {
46 FullSpan(s) | FileLine(s) => s
49 fn is_full_span(&self) -> bool {
51 &FullSpan(..) => true,
52 &FileLine(..) => false,
57 #[derive(Clone, Copy)]
58 pub enum ColorConfig {
65 fn emit(&mut self, cmsp: Option<(&codemap::CodeMap, Span)>,
66 msg: &str, code: Option<&str>, lvl: Level);
67 fn custom_emit(&mut self, cm: &codemap::CodeMap,
68 sp: RenderSpan, msg: &str, lvl: Level);
71 /// This structure is used to signify that a task has panicked with a fatal error
72 /// from the diagnostics. You can use this with the `Any` trait to figure out
73 /// how a rustc task died (if so desired).
75 pub struct FatalError;
77 /// Signifies that the compiler died with an explicit call to `.bug`
78 /// or `.span_bug` rather than a failed assertion, etc.
80 pub struct ExplicitBug;
82 /// A span-handler is like a handler but also
83 /// accepts span information for source-location
85 pub struct SpanHandler {
87 pub cm: codemap::CodeMap,
91 pub fn span_fatal(&self, sp: Span, msg: &str) -> ! {
92 self.handler.emit(Some((&self.cm, sp)), msg, Fatal);
95 pub fn span_fatal_with_code(&self, sp: Span, msg: &str, code: &str) -> ! {
96 self.handler.emit_with_code(Some((&self.cm, sp)), msg, code, Fatal);
99 pub fn span_err(&self, sp: Span, msg: &str) {
100 self.handler.emit(Some((&self.cm, sp)), msg, Error);
101 self.handler.bump_err_count();
103 pub fn span_err_with_code(&self, sp: Span, msg: &str, code: &str) {
104 self.handler.emit_with_code(Some((&self.cm, sp)), msg, code, Error);
105 self.handler.bump_err_count();
107 pub fn span_warn(&self, sp: Span, msg: &str) {
108 self.handler.emit(Some((&self.cm, sp)), msg, Warning);
110 pub fn span_warn_with_code(&self, sp: Span, msg: &str, code: &str) {
111 self.handler.emit_with_code(Some((&self.cm, sp)), msg, code, Warning);
113 pub fn span_note(&self, sp: Span, msg: &str) {
114 self.handler.emit(Some((&self.cm, sp)), msg, Note);
116 pub fn span_end_note(&self, sp: Span, msg: &str) {
117 self.handler.custom_emit(&self.cm, FullSpan(sp), msg, Note);
119 pub fn span_help(&self, sp: Span, msg: &str) {
120 self.handler.emit(Some((&self.cm, sp)), msg, Help);
122 pub fn fileline_note(&self, sp: Span, msg: &str) {
123 self.handler.custom_emit(&self.cm, FileLine(sp), msg, Note);
125 pub fn fileline_help(&self, sp: Span, msg: &str) {
126 self.handler.custom_emit(&self.cm, FileLine(sp), msg, Help);
128 pub fn span_bug(&self, sp: Span, msg: &str) -> ! {
129 self.handler.emit(Some((&self.cm, sp)), msg, Bug);
132 pub fn span_unimpl(&self, sp: Span, msg: &str) -> ! {
133 self.span_bug(sp, &format!("unimplemented {}", msg)[]);
135 pub fn handler<'a>(&'a self) -> &'a Handler {
140 /// A handler deals with errors; certain errors
141 /// (fatal, bug, unimpl) may cause immediate exit,
142 /// others log errors for later reporting.
144 err_count: Cell<usize>,
145 emit: RefCell<Box<Emitter + Send>>,
149 pub fn fatal(&self, msg: &str) -> ! {
150 self.emit.borrow_mut().emit(None, msg, None, Fatal);
153 pub fn err(&self, msg: &str) {
154 self.emit.borrow_mut().emit(None, msg, None, Error);
155 self.bump_err_count();
157 pub fn bump_err_count(&self) {
158 self.err_count.set(self.err_count.get() + 1us);
160 pub fn err_count(&self) -> usize {
163 pub fn has_errors(&self) -> bool {
164 self.err_count.get() > 0us
166 pub fn abort_if_errors(&self) {
168 match self.err_count.get() {
170 1us => s = "aborting due to previous error".to_string(),
172 s = format!("aborting due to {} previous errors",
173 self.err_count.get());
178 pub fn warn(&self, msg: &str) {
179 self.emit.borrow_mut().emit(None, msg, None, Warning);
181 pub fn note(&self, msg: &str) {
182 self.emit.borrow_mut().emit(None, msg, None, Note);
184 pub fn help(&self, msg: &str) {
185 self.emit.borrow_mut().emit(None, msg, None, Help);
187 pub fn bug(&self, msg: &str) -> ! {
188 self.emit.borrow_mut().emit(None, msg, None, Bug);
191 pub fn unimpl(&self, msg: &str) -> ! {
192 self.bug(&format!("unimplemented {}", msg)[]);
195 cmsp: Option<(&codemap::CodeMap, Span)>,
198 self.emit.borrow_mut().emit(cmsp, msg, None, lvl);
200 pub fn emit_with_code(&self,
201 cmsp: Option<(&codemap::CodeMap, Span)>,
205 self.emit.borrow_mut().emit(cmsp, msg, Some(code), lvl);
207 pub fn custom_emit(&self, cm: &codemap::CodeMap,
208 sp: RenderSpan, msg: &str, lvl: Level) {
209 self.emit.borrow_mut().custom_emit(cm, sp, msg, lvl);
213 pub fn mk_span_handler(handler: Handler, cm: codemap::CodeMap) -> SpanHandler {
220 pub fn default_handler(color_config: ColorConfig,
221 registry: Option<diagnostics::registry::Registry>) -> Handler {
222 mk_handler(box EmitterWriter::stderr(color_config, registry))
225 pub fn mk_handler(e: Box<Emitter + Send>) -> Handler {
227 err_count: Cell::new(0),
228 emit: RefCell::new(e),
232 #[derive(Copy, PartialEq, Clone, Show)]
242 impl fmt::String for Level {
243 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
244 use std::fmt::String;
247 Bug => "error: internal compiler error".fmt(f),
248 Fatal | Error => "error".fmt(f),
249 Warning => "warning".fmt(f),
250 Note => "note".fmt(f),
251 Help => "help".fmt(f),
257 fn color(self) -> term::color::Color {
259 Bug | Fatal | Error => term::color::BRIGHT_RED,
260 Warning => term::color::BRIGHT_YELLOW,
261 Note => term::color::BRIGHT_GREEN,
262 Help => term::color::BRIGHT_CYAN,
267 fn print_maybe_styled(w: &mut EmitterWriter,
269 color: term::attr::Attr) -> io::IoResult<()> {
271 Terminal(ref mut t) => {
273 // If `msg` ends in a newline, we need to reset the color before
274 // the newline. We're making the assumption that we end up writing
275 // to a `LineBufferedWriter`, which means that emitting the reset
276 // after the newline ends up buffering the reset until we print
277 // another line or exit. Buffering the reset is a problem if we're
278 // sharing the terminal with any other programs (e.g. other rustc
279 // instances via `make -jN`).
281 // Note that if `msg` contains any internal newlines, this will
282 // result in the `LineBufferedWriter` flushing twice instead of
283 // once, which still leaves the opportunity for interleaved output
284 // to be miscolored. We assume this is rare enough that we don't
285 // have to worry about it.
286 if msg.ends_with("\n") {
287 try!(t.write_str(&msg[..(msg.len()-1)]));
289 try!(t.write_str("\n"));
291 try!(t.write_str(msg));
302 fn print_diagnostic(dst: &mut EmitterWriter, topic: &str, lvl: Level,
303 msg: &str, code: Option<&str>) -> io::IoResult<()> {
304 if !topic.is_empty() {
305 try!(write!(&mut dst.dst, "{} ", topic));
308 try!(print_maybe_styled(dst,
309 &format!("{}: ", lvl.to_string())[],
310 term::attr::ForegroundColor(lvl.color())));
311 try!(print_maybe_styled(dst,
312 &format!("{}", msg)[],
317 let style = term::attr::ForegroundColor(term::color::BRIGHT_MAGENTA);
318 try!(print_maybe_styled(dst, &format!(" [{}]", code.clone())[], style));
322 try!(dst.dst.write_char('\n'));
326 pub struct EmitterWriter {
328 registry: Option<diagnostics::registry::Registry>
332 Terminal(Box<term::Terminal<WriterWrapper> + Send>),
333 Raw(Box<Writer + Send>),
337 pub fn stderr(color_config: ColorConfig,
338 registry: Option<diagnostics::registry::Registry>) -> EmitterWriter {
339 let stderr = io::stderr();
341 let use_color = match color_config {
344 Auto => stderr.get_ref().isatty()
348 let dst = match term::stderr() {
349 Some(t) => Terminal(t),
350 None => Raw(box stderr),
352 EmitterWriter { dst: dst, registry: registry }
354 EmitterWriter { dst: Raw(box stderr), registry: registry }
358 pub fn new(dst: Box<Writer + Send>,
359 registry: Option<diagnostics::registry::Registry>) -> EmitterWriter {
360 EmitterWriter { dst: Raw(dst), registry: registry }
364 impl Writer for Destination {
365 fn write(&mut self, bytes: &[u8]) -> io::IoResult<()> {
367 Terminal(ref mut t) => t.write(bytes),
368 Raw(ref mut w) => w.write(bytes),
373 impl Emitter for EmitterWriter {
375 cmsp: Option<(&codemap::CodeMap, Span)>,
376 msg: &str, code: Option<&str>, lvl: Level) {
377 let error = match cmsp {
378 Some((cm, COMMAND_LINE_SP)) => emit(self, cm,
379 FileLine(COMMAND_LINE_SP),
380 msg, code, lvl, false),
381 Some((cm, sp)) => emit(self, cm, FullSpan(sp), msg, code, lvl, false),
382 None => print_diagnostic(self, "", lvl, msg, code),
387 Err(e) => panic!("failed to print diagnostics: {:?}", e),
391 fn custom_emit(&mut self, cm: &codemap::CodeMap,
392 sp: RenderSpan, msg: &str, lvl: Level) {
393 match emit(self, cm, sp, msg, None, lvl, true) {
395 Err(e) => panic!("failed to print diagnostics: {:?}", e),
400 fn emit(dst: &mut EmitterWriter, cm: &codemap::CodeMap, rsp: RenderSpan,
401 msg: &str, code: Option<&str>, lvl: Level, custom: bool) -> io::IoResult<()> {
404 // We cannot check equality directly with COMMAND_LINE_SP
405 // since PartialEq is manually implemented to ignore the ExpnId
406 let ss = if sp.expn_id == COMMAND_LINE_EXPN {
407 "<command line option>".to_string()
409 cm.span_to_string(sp)
412 // we want to tell compiletest/runtest to look at the last line of the
413 // span (since `custom_highlight_lines` displays an arrow to the end of
415 let span_end = Span { lo: sp.hi, hi: sp.hi, expn_id: sp.expn_id};
416 let ses = cm.span_to_string(span_end);
417 try!(print_diagnostic(dst, &ses[], lvl, msg, code));
418 if rsp.is_full_span() {
419 try!(custom_highlight_lines(dst, cm, sp, lvl, cm.span_to_lines(sp)));
422 try!(print_diagnostic(dst, &ss[], lvl, msg, code));
423 if rsp.is_full_span() {
424 try!(highlight_lines(dst, cm, sp, lvl, cm.span_to_lines(sp)));
427 if sp != COMMAND_LINE_SP {
428 try!(print_macro_backtrace(dst, cm, sp));
432 match dst.registry.as_ref().and_then(|registry| registry.find_description(code)) {
434 try!(print_diagnostic(dst, &ss[], Help,
435 &format!("pass `--explain {}` to see a detailed \
436 explanation", code)[], None));
445 fn highlight_lines(err: &mut EmitterWriter,
446 cm: &codemap::CodeMap,
449 lines: codemap::FileLines) -> io::IoResult<()> {
450 let fm = &*lines.file;
452 let mut elided = false;
453 let mut display_lines = &lines.lines[];
454 if display_lines.len() > MAX_LINES {
455 display_lines = &display_lines[0us..MAX_LINES];
458 // Print the offending lines
459 for &line_number in display_lines.iter() {
460 if let Some(line) = fm.get_line(line_number) {
461 try!(write!(&mut err.dst, "{}:{} {}\n", fm.name,
462 line_number + 1, line));
466 let last_line = display_lines[display_lines.len() - 1us];
467 let s = format!("{}:{} ", fm.name, last_line + 1us);
468 try!(write!(&mut err.dst, "{0:1$}...\n", "", s.len()));
472 // If there's one line at fault we can easily point to the problem
473 if lines.lines.len() == 1us {
474 let lo = cm.lookup_char_pos(sp.lo);
475 let mut digits = 0us;
476 let mut num = (lines.lines[0] + 1us) / 10us;
478 // how many digits must be indent past?
479 while num > 0us { num /= 10us; digits += 1us; }
481 // indent past |name:## | and the 0-offset column location
482 let left = fm.name.len() + digits + lo.col.to_usize() + 3us;
483 let mut s = String::new();
484 // Skip is the number of characters we need to skip because they are
485 // part of the 'filename:line ' part of the previous line.
486 let skip = fm.name.len() + digits + 3us;
487 for _ in range(0, skip) {
490 if let Some(orig) = fm.get_line(lines.lines[0]) {
491 for pos in range(0us, left - skip) {
492 let cur_char = orig.as_bytes()[pos] as char;
493 // Whenever a tab occurs on the previous line, we insert one on
494 // the error-point-squiggly-line as well (instead of a space).
495 // That way the squiggly line will usually appear in the correct
498 '\t' => s.push('\t'),
504 try!(write!(&mut err.dst, "{}", s));
505 let mut s = String::from_str("^");
506 let hi = cm.lookup_char_pos(sp.hi);
507 if hi.col != lo.col {
508 // the ^ already takes up one space
509 let num_squigglies = hi.col.to_usize() - lo.col.to_usize() - 1us;
510 for _ in range(0, num_squigglies) {
514 try!(print_maybe_styled(err,
515 &format!("{}\n", s)[],
516 term::attr::ForegroundColor(lvl.color())));
521 /// Here are the differences between this and the normal `highlight_lines`:
522 /// `custom_highlight_lines` will always put arrow on the last byte of the
523 /// span (instead of the first byte). Also, when the span is too long (more
524 /// than 6 lines), `custom_highlight_lines` will print the first line, then
525 /// dot dot dot, then last line, whereas `highlight_lines` prints the first
527 fn custom_highlight_lines(w: &mut EmitterWriter,
528 cm: &codemap::CodeMap,
531 lines: codemap::FileLines)
532 -> io::IoResult<()> {
533 let fm = &*lines.file;
535 let lines = &lines.lines[];
536 if lines.len() > MAX_LINES {
537 if let Some(line) = fm.get_line(lines[0]) {
538 try!(write!(&mut w.dst, "{}:{} {}\n", fm.name,
539 lines[0] + 1, line));
541 try!(write!(&mut w.dst, "...\n"));
542 let last_line_number = lines[lines.len() - 1];
543 if let Some(last_line) = fm.get_line(last_line_number) {
544 try!(write!(&mut w.dst, "{}:{} {}\n", fm.name,
545 last_line_number + 1, last_line));
548 for &line_number in lines.iter() {
549 if let Some(line) = fm.get_line(line_number) {
550 try!(write!(&mut w.dst, "{}:{} {}\n", fm.name,
551 line_number + 1, line));
555 let last_line_start = format!("{}:{} ", fm.name, lines[lines.len()-1]+1);
556 let hi = cm.lookup_char_pos(sp.hi);
557 // Span seems to use half-opened interval, so subtract 1
558 let skip = last_line_start.len() + hi.col.to_usize() - 1;
559 let mut s = String::new();
560 for _ in range(0, skip) {
565 print_maybe_styled(w,
567 term::attr::ForegroundColor(lvl.color()))
570 fn print_macro_backtrace(w: &mut EmitterWriter,
571 cm: &codemap::CodeMap,
573 -> io::IoResult<()> {
574 let cs = try!(cm.with_expn_info(sp.expn_id, |expn_info| match expn_info {
576 let ss = ei.callee.span.map_or(String::new(), |span| cm.span_to_string(span));
577 let (pre, post) = match ei.callee.format {
578 codemap::MacroAttribute => ("#[", "]"),
579 codemap::MacroBang => ("", "!")
581 try!(print_diagnostic(w, &ss[], Note,
582 &format!("in expansion of {}{}{}", pre,
585 let ss = cm.span_to_string(ei.call_site);
586 try!(print_diagnostic(w, &ss[], Note, "expansion site", None));
587 Ok(Some(ei.call_site))
591 cs.map_or(Ok(()), |call_site| print_macro_backtrace(w, cm, call_site))
594 pub fn expect<T, M>(diag: &SpanHandler, opt: Option<T>, msg: M) -> T where
595 M: FnOnce() -> String,
599 None => diag.handler().bug(&msg()[]),