rust/src/libsyntax/diagnostic.rs

555 lines
18 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
extern crate libc;
use codemap::{Pos, Span};
use codemap;
use diagnostics;
use std::cell::{RefCell, Cell};
use std::fmt;
use std::io;
use std::iter::range;
use std::string::String;
use term::WriterWrapper;
use term;
/// maximum number of lines we will print for each error; arbitrary.
static MAX_LINES: uint = 6u;
#[deriving(Clone)]
pub enum RenderSpan {
/// A FullSpan renders with both with an initial line for the
/// message, prefixed by file:linenum, followed by a summary of
/// the source code covered by the span.
FullSpan(Span),
/// A FileLine renders with just a line for the message prefixed
/// by file:linenum.
FileLine(Span),
}
impl RenderSpan {
fn span(self) -> Span {
match self {
FullSpan(s) | FileLine(s) => s
}
}
fn is_full_span(&self) -> bool {
match self {
&FullSpan(..) => true,
&FileLine(..) => false,
}
}
}
#[deriving(Clone)]
pub enum ColorConfig {
Auto,
Always,
Never
}
pub trait Emitter {
fn emit(&mut self, cmsp: Option<(&codemap::CodeMap, Span)>,
msg: &str, code: Option<&str>, lvl: Level);
fn custom_emit(&mut self, cm: &codemap::CodeMap,
sp: RenderSpan, msg: &str, lvl: Level);
}
/// This structure is used to signify that a task has failed with a fatal error
/// from the diagnostics. You can use this with the `Any` trait to figure out
/// how a rustc task died (if so desired).
pub struct FatalError;
/// Signifies that the compiler died with an explicit call to `.bug`
/// or `.span_bug` rather than a failed assertion, etc.
pub struct ExplicitBug;
/// A span-handler is like a handler but also
/// accepts span information for source-location
/// reporting.
pub struct SpanHandler {
pub handler: Handler,
pub cm: codemap::CodeMap,
}
impl SpanHandler {
pub fn span_fatal(&self, sp: Span, msg: &str) -> ! {
self.handler.emit(Some((&self.cm, sp)), msg, Fatal);
fail!(FatalError);
}
pub fn span_err(&self, sp: Span, msg: &str) {
self.handler.emit(Some((&self.cm, sp)), msg, Error);
self.handler.bump_err_count();
}
pub fn span_err_with_code(&self, sp: Span, msg: &str, code: &str) {
self.handler.emit_with_code(Some((&self.cm, sp)), msg, code, Error);
self.handler.bump_err_count();
}
pub fn span_warn(&self, sp: Span, msg: &str) {
self.handler.emit(Some((&self.cm, sp)), msg, Warning);
}
pub fn span_warn_with_code(&self, sp: Span, msg: &str, code: &str) {
self.handler.emit_with_code(Some((&self.cm, sp)), msg, code, Warning);
}
pub fn span_note(&self, sp: Span, msg: &str) {
self.handler.emit(Some((&self.cm, sp)), msg, Note);
}
pub fn span_end_note(&self, sp: Span, msg: &str) {
self.handler.custom_emit(&self.cm, FullSpan(sp), msg, Note);
}
pub fn fileline_note(&self, sp: Span, msg: &str) {
self.handler.custom_emit(&self.cm, FileLine(sp), msg, Note);
}
pub fn span_bug(&self, sp: Span, msg: &str) -> ! {
self.handler.emit(Some((&self.cm, sp)), msg, Bug);
fail!(ExplicitBug);
}
pub fn span_unimpl(&self, sp: Span, msg: &str) -> ! {
self.span_bug(sp, format!("unimplemented {}", msg).as_slice());
}
pub fn handler<'a>(&'a self) -> &'a Handler {
&self.handler
}
}
/// A handler deals with errors; certain errors
/// (fatal, bug, unimpl) may cause immediate exit,
/// others log errors for later reporting.
pub struct Handler {
err_count: Cell<uint>,
emit: RefCell<Box<Emitter + Send>>,
}
impl Handler {
pub fn fatal(&self, msg: &str) -> ! {
self.emit.borrow_mut().emit(None, msg, None, Fatal);
fail!(FatalError);
}
pub fn err(&self, msg: &str) {
self.emit.borrow_mut().emit(None, msg, None, Error);
self.bump_err_count();
}
pub fn bump_err_count(&self) {
self.err_count.set(self.err_count.get() + 1u);
}
pub fn err_count(&self) -> uint {
self.err_count.get()
}
pub fn has_errors(&self) -> bool {
self.err_count.get()> 0u
}
pub fn abort_if_errors(&self) {
let s;
match self.err_count.get() {
0u => return,
1u => s = "aborting due to previous error".to_string(),
_ => {
s = format!("aborting due to {} previous errors",
self.err_count.get());
}
}
self.fatal(s.as_slice());
}
pub fn warn(&self, msg: &str) {
self.emit.borrow_mut().emit(None, msg, None, Warning);
}
pub fn note(&self, msg: &str) {
self.emit.borrow_mut().emit(None, msg, None, Note);
}
pub fn bug(&self, msg: &str) -> ! {
self.emit.borrow_mut().emit(None, msg, None, Bug);
fail!(ExplicitBug);
}
pub fn unimpl(&self, msg: &str) -> ! {
self.bug(format!("unimplemented {}", msg).as_slice());
}
pub fn emit(&self,
cmsp: Option<(&codemap::CodeMap, Span)>,
msg: &str,
lvl: Level) {
self.emit.borrow_mut().emit(cmsp, msg, None, lvl);
}
pub fn emit_with_code(&self,
cmsp: Option<(&codemap::CodeMap, Span)>,
msg: &str,
code: &str,
lvl: Level) {
self.emit.borrow_mut().emit(cmsp, msg, Some(code), lvl);
}
pub fn custom_emit(&self, cm: &codemap::CodeMap,
sp: RenderSpan, msg: &str, lvl: Level) {
self.emit.borrow_mut().custom_emit(cm, sp, msg, lvl);
}
}
pub fn mk_span_handler(handler: Handler, cm: codemap::CodeMap) -> SpanHandler {
SpanHandler {
handler: handler,
cm: cm,
}
}
pub fn default_handler(color_config: ColorConfig,
registry: Option<diagnostics::registry::Registry>) -> Handler {
mk_handler(box EmitterWriter::stderr(color_config, registry))
}
pub fn mk_handler(e: Box<Emitter + Send>) -> Handler {
Handler {
err_count: Cell::new(0),
emit: RefCell::new(e),
}
}
#[deriving(PartialEq)]
pub enum Level {
Bug,
Fatal,
Error,
Warning,
Note,
}
impl fmt::Show for Level {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use std::fmt::Show;
match *self {
Bug => "error: internal compiler error".fmt(f),
Fatal | Error => "error".fmt(f),
Warning => "warning".fmt(f),
Note => "note".fmt(f),
}
}
}
impl Level {
fn color(self) -> term::color::Color {
match self {
Bug | Fatal | Error => term::color::BRIGHT_RED,
Warning => term::color::BRIGHT_YELLOW,
Note => term::color::BRIGHT_GREEN
}
}
}
fn print_maybe_styled(w: &mut EmitterWriter,
msg: &str,
color: term::attr::Attr) -> io::IoResult<()> {
match w.dst {
Terminal(ref mut t) => {
try!(t.attr(color));
// If `msg` ends in a newline, we need to reset the color before
// the newline. We're making the assumption that we end up writing
// to a `LineBufferedWriter`, which means that emitting the reset
// after the newline ends up buffering the reset until we print
// another line or exit. Buffering the reset is a problem if we're
// sharing the terminal with any other programs (e.g. other rustc
// instances via `make -jN`).
//
// Note that if `msg` contains any internal newlines, this will
// result in the `LineBufferedWriter` flushing twice instead of
// once, which still leaves the opportunity for interleaved output
// to be miscolored. We assume this is rare enough that we don't
// have to worry about it.
if msg.ends_with("\n") {
try!(t.write_str(msg.slice_to(msg.len()-1)));
try!(t.reset());
try!(t.write_str("\n"));
} else {
try!(t.write_str(msg));
try!(t.reset());
}
Ok(())
}
Raw(ref mut w) => {
w.write_str(msg)
}
}
}
fn print_diagnostic(dst: &mut EmitterWriter, topic: &str, lvl: Level,
msg: &str, code: Option<&str>) -> io::IoResult<()> {
if !topic.is_empty() {
try!(write!(&mut dst.dst, "{} ", topic));
}
try!(print_maybe_styled(dst,
format!("{}: ", lvl.to_string()).as_slice(),
term::attr::ForegroundColor(lvl.color())));
try!(print_maybe_styled(dst,
format!("{}", msg).as_slice(),
term::attr::Bold));
match code {
Some(code) => {
let style = term::attr::ForegroundColor(term::color::BRIGHT_MAGENTA);
try!(print_maybe_styled(dst, format!(" [{}]", code.clone()).as_slice(), style));
match dst.registry.as_ref().and_then(|registry| registry.find_description(code)) {
Some(_) => {
try!(write!(&mut dst.dst,
" (pass `--explain {}` to see a detailed explanation)",
code
));
}
None => ()
}
}
None => ()
}
try!(dst.dst.write_char('\n'));
Ok(())
}
pub struct EmitterWriter {
dst: Destination,
registry: Option<diagnostics::registry::Registry>
}
enum Destination {
Terminal(Box<term::Terminal<WriterWrapper> + Send>),
Raw(Box<Writer + Send>),
}
impl EmitterWriter {
pub fn stderr(color_config: ColorConfig,
registry: Option<diagnostics::registry::Registry>) -> EmitterWriter {
let stderr = io::stderr();
let use_color = match color_config {
Always => true,
Never => false,
Auto => stderr.get_ref().isatty()
};
if use_color {
let dst = match term::stderr() {
Some(t) => Terminal(t),
None => Raw(box stderr),
};
EmitterWriter { dst: dst, registry: registry }
} else {
EmitterWriter { dst: Raw(box stderr), registry: registry }
}
}
pub fn new(dst: Box<Writer + Send>,
registry: Option<diagnostics::registry::Registry>) -> EmitterWriter {
EmitterWriter { dst: Raw(dst), registry: registry }
}
}
impl Writer for Destination {
fn write(&mut self, bytes: &[u8]) -> io::IoResult<()> {
match *self {
Terminal(ref mut t) => t.write(bytes),
Raw(ref mut w) => w.write(bytes),
}
}
}
impl Emitter for EmitterWriter {
fn emit(&mut self,
cmsp: Option<(&codemap::CodeMap, Span)>,
msg: &str, code: Option<&str>, lvl: Level) {
let error = match cmsp {
Some((cm, sp)) => emit(self, cm, FullSpan(sp), msg, code, lvl, false),
None => print_diagnostic(self, "", lvl, msg, code),
};
match error {
Ok(()) => {}
Err(e) => fail!("failed to print diagnostics: {}", e),
}
}
fn custom_emit(&mut self, cm: &codemap::CodeMap,
sp: RenderSpan, msg: &str, lvl: Level) {
match emit(self, cm, sp, msg, None, lvl, true) {
Ok(()) => {}
Err(e) => fail!("failed to print diagnostics: {}", e),
}
}
}
fn emit(dst: &mut EmitterWriter, cm: &codemap::CodeMap, rsp: RenderSpan,
msg: &str, code: Option<&str>, lvl: Level, custom: bool) -> io::IoResult<()> {
let sp = rsp.span();
let ss = cm.span_to_string(sp);
let lines = cm.span_to_lines(sp);
if custom {
// we want to tell compiletest/runtest to look at the last line of the
// span (since `custom_highlight_lines` displays an arrow to the end of
// the span)
let span_end = Span { lo: sp.hi, hi: sp.hi, expn_info: sp.expn_info};
let ses = cm.span_to_string(span_end);
try!(print_diagnostic(dst, ses.as_slice(), lvl, msg, code));
if rsp.is_full_span() {
try!(custom_highlight_lines(dst, cm, sp, lvl, lines));
}
} else {
try!(print_diagnostic(dst, ss.as_slice(), lvl, msg, code));
if rsp.is_full_span() {
try!(highlight_lines(dst, cm, sp, lvl, lines));
}
}
print_macro_backtrace(dst, cm, sp)
}
fn highlight_lines(err: &mut EmitterWriter,
cm: &codemap::CodeMap,
sp: Span,
lvl: Level,
lines: codemap::FileLines) -> io::IoResult<()> {
let fm = &*lines.file;
let mut elided = false;
let mut display_lines = lines.lines.as_slice();
if display_lines.len() > MAX_LINES {
display_lines = display_lines.slice(0u, MAX_LINES);
elided = true;
}
// Print the offending lines
for line in display_lines.iter() {
try!(write!(&mut err.dst, "{}:{} {}\n", fm.name, *line + 1,
fm.get_line(*line as int)));
}
if elided {
let last_line = display_lines[display_lines.len() - 1u];
let s = format!("{}:{} ", fm.name, last_line + 1u);
try!(write!(&mut err.dst, "{0:1$}...\n", "", s.len()));
}
// FIXME (#3260)
// If there's one line at fault we can easily point to the problem
if lines.lines.len() == 1u {
let lo = cm.lookup_char_pos(sp.lo);
let mut digits = 0u;
let mut num = (*lines.lines.get(0) + 1u) / 10u;
// how many digits must be indent past?
while num > 0u { num /= 10u; digits += 1u; }
// indent past |name:## | and the 0-offset column location
let left = fm.name.len() + digits + lo.col.to_uint() + 3u;
let mut s = String::new();
// Skip is the number of characters we need to skip because they are
// part of the 'filename:line ' part of the previous line.
let skip = fm.name.len() + digits + 3u;
for _ in range(0, skip) {
s.push_char(' ');
}
let orig = fm.get_line(*lines.lines.get(0) as int);
for pos in range(0u, left-skip) {
let cur_char = orig.as_bytes()[pos] as char;
// Whenever a tab occurs on the previous line, we insert one on
// the error-point-squiggly-line as well (instead of a space).
// That way the squiggly line will usually appear in the correct
// position.
match cur_char {
'\t' => s.push_char('\t'),
_ => s.push_char(' '),
};
}
try!(write!(&mut err.dst, "{}", s));
let mut s = String::from_str("^");
let hi = cm.lookup_char_pos(sp.hi);
if hi.col != lo.col {
// the ^ already takes up one space
let num_squigglies = hi.col.to_uint()-lo.col.to_uint()-1u;
for _ in range(0, num_squigglies) {
s.push_char('~');
}
}
try!(print_maybe_styled(err,
format!("{}\n", s).as_slice(),
term::attr::ForegroundColor(lvl.color())));
}
Ok(())
}
/// Here are the differences between this and the normal `highlight_lines`:
/// `custom_highlight_lines` will always put arrow on the last byte of the
/// span (instead of the first byte). Also, when the span is too long (more
/// than 6 lines), `custom_highlight_lines` will print the first line, then
/// dot dot dot, then last line, whereas `highlight_lines` prints the first
/// six lines.
fn custom_highlight_lines(w: &mut EmitterWriter,
cm: &codemap::CodeMap,
sp: Span,
lvl: Level,
lines: codemap::FileLines)
-> io::IoResult<()> {
let fm = &*lines.file;
let lines = lines.lines.as_slice();
if lines.len() > MAX_LINES {
try!(write!(&mut w.dst, "{}:{} {}\n", fm.name,
lines[0] + 1, fm.get_line(lines[0] as int)));
try!(write!(&mut w.dst, "...\n"));
let last_line = lines[lines.len()-1];
try!(write!(&mut w.dst, "{}:{} {}\n", fm.name,
last_line + 1, fm.get_line(last_line as int)));
} else {
for line in lines.iter() {
try!(write!(&mut w.dst, "{}:{} {}\n", fm.name,
*line + 1, fm.get_line(*line as int)));
}
}
let last_line_start = format!("{}:{} ", fm.name, lines[lines.len()-1]+1);
let hi = cm.lookup_char_pos(sp.hi);
// Span seems to use half-opened interval, so subtract 1
let skip = last_line_start.len() + hi.col.to_uint() - 1;
let mut s = String::new();
for _ in range(0, skip) {
s.push_char(' ');
}
s.push_char('^');
s.push_char('\n');
print_maybe_styled(w,
s.as_slice(),
term::attr::ForegroundColor(lvl.color()))
}
fn print_macro_backtrace(w: &mut EmitterWriter,
cm: &codemap::CodeMap,
sp: Span)
-> io::IoResult<()> {
for ei in sp.expn_info.iter() {
let ss = ei.callee
.span
.as_ref()
.map_or("".to_string(), |span| cm.span_to_string(*span));
let (pre, post) = match ei.callee.format {
codemap::MacroAttribute => ("#[", "]"),
codemap::MacroBang => ("", "!")
};
try!(print_diagnostic(w, ss.as_slice(), Note,
format!("in expansion of {}{}{}", pre,
ei.callee.name,
post).as_slice(), None));
let ss = cm.span_to_string(ei.call_site);
try!(print_diagnostic(w, ss.as_slice(), Note, "expansion site", None));
try!(print_macro_backtrace(w, cm, ei.call_site));
}
Ok(())
}
pub fn expect<T:Clone>(diag: &SpanHandler, opt: Option<T>, msg: || -> String)
-> T {
match opt {
Some(ref t) => (*t).clone(),
None => diag.handler().bug(msg().as_slice()),
}
}