rust/src/libsyntax/errors/emitter.rs
Niko Matsakis 11dc974a38 refactor to use new snippet code and model
Major changes:
- Remove old snippet rendering code and use the new stuff.
- Introduce `span_label` method to add a label
- Remove EndSpan mode and replace with a fn to get the last
  character of a span.
- Stop using `Option<MultiSpan>` and just use an empty `MultiSpan`
- and probably a bunch of other stuff :)
2016-05-02 11:47:10 -04:00

744 lines
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Rust
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// Copyright 2012-2015 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.
use self::Destination::*;
use codemap::{self, COMMAND_LINE_SP, DUMMY_SP, Pos, Span, MultiSpan};
use diagnostics;
use errors::{Level, RenderSpan, CodeSuggestion, DiagnosticBuilder};
use errors::RenderSpan::*;
use errors::Level::*;
use errors::snippet::{RenderedLineKind, SnippetData, Style};
use std::{cmp, fmt};
use std::io::prelude::*;
use std::io;
use std::rc::Rc;
use term;
pub trait Emitter {
fn emit(&mut self, span: &MultiSpan, msg: &str, code: Option<&str>, lvl: Level);
/// Emit a structured diagnostic.
fn emit_struct(&mut self, db: &DiagnosticBuilder);
}
/// maximum number of lines we will print for each error; arbitrary.
pub const MAX_HIGHLIGHT_LINES: usize = 6;
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum ColorConfig {
Auto,
Always,
Never,
}
impl ColorConfig {
fn use_color(&self) -> bool {
match *self {
ColorConfig::Always => true,
ColorConfig::Never => false,
ColorConfig::Auto => stderr_isatty(),
}
}
}
/// A basic emitter for when we don't have access to a codemap or registry. Used
/// for reporting very early errors, etc.
pub struct BasicEmitter {
dst: Destination,
}
impl Emitter for BasicEmitter {
fn emit(&mut self,
msp: &MultiSpan,
msg: &str,
code: Option<&str>,
lvl: Level) {
assert!(msp.primary_span().is_none(), "BasicEmitter can't handle spans");
if let Err(e) = print_diagnostic(&mut self.dst, "", lvl, msg, code) {
panic!("failed to print diagnostics: {:?}", e);
}
}
fn emit_struct(&mut self, db: &DiagnosticBuilder) {
self.emit(&db.span, &db.message, db.code.as_ref().map(|s| &**s), db.level);
for child in &db.children {
assert!(child.render_span.is_none(), "BasicEmitter can't handle spans");
self.emit(&child.span, &child.message, None, child.level);
}
}
}
impl BasicEmitter {
pub fn stderr(color_config: ColorConfig) -> BasicEmitter {
if color_config.use_color() {
let dst = Destination::from_stderr();
BasicEmitter { dst: dst }
} else {
BasicEmitter { dst: Raw(Box::new(io::stderr())) }
}
}
}
pub struct EmitterWriter {
dst: Destination,
registry: Option<diagnostics::registry::Registry>,
cm: Rc<codemap::CodeMap>,
first: bool,
}
impl Emitter for EmitterWriter {
fn emit(&mut self,
msp: &MultiSpan,
msg: &str,
code: Option<&str>,
lvl: Level) {
self.emit_multispan(msp, msg, code, lvl, true);
}
fn emit_struct(&mut self, db: &DiagnosticBuilder) {
self.emit_multispan(&db.span, &db.message,
db.code.as_ref().map(|s| &**s), db.level, true);
for child in &db.children {
match child.render_span {
Some(ref sp) =>
self.emit_renderspan(sp, &child.message,
child.level),
None =>
self.emit_multispan(&child.span,
&child.message, None, child.level, false),
}
}
}
}
/// Do not use this for messages that end in `\n` use `println_maybe_styled` instead. See
/// `EmitterWriter::print_maybe_styled` for details.
macro_rules! print_maybe_styled {
($dst: expr, $style: expr, $($arg: tt)*) => {
$dst.print_maybe_styled(format_args!($($arg)*), $style, false)
}
}
macro_rules! println_maybe_styled {
($dst: expr, $style: expr, $($arg: tt)*) => {
$dst.print_maybe_styled(format_args!($($arg)*), $style, true)
}
}
impl EmitterWriter {
pub fn stderr(color_config: ColorConfig,
registry: Option<diagnostics::registry::Registry>,
code_map: Rc<codemap::CodeMap>)
-> EmitterWriter {
if color_config.use_color() {
let dst = Destination::from_stderr();
EmitterWriter { dst: dst, registry: registry, cm: code_map, first: true }
} else {
EmitterWriter { dst: Raw(Box::new(io::stderr())),
registry: registry, cm: code_map, first: true }
}
}
pub fn new(dst: Box<Write + Send>,
registry: Option<diagnostics::registry::Registry>,
code_map: Rc<codemap::CodeMap>)
-> EmitterWriter {
EmitterWriter { dst: Raw(dst), registry: registry, cm: code_map, first: true }
}
fn emit_multispan(&mut self,
span: &MultiSpan,
msg: &str,
code: Option<&str>,
lvl: Level,
is_header: bool) {
if is_header {
if self.first {
self.first = false;
} else {
match write!(self.dst, "\n") {
Ok(_) => { }
Err(e) => {
panic!("failed to print diagnostics: {:?}", e)
}
}
}
}
let error = match span.primary_span() {
Some(COMMAND_LINE_SP) => {
self.emit_(&FileLine(span.clone()), msg, code, lvl)
}
Some(DUMMY_SP) | None => {
print_diagnostic(&mut self.dst, "", lvl, msg, code)
}
Some(_) => {
self.emit_(&FullSpan(span.clone()), msg, code, lvl)
}
};
if let Err(e) = error {
panic!("failed to print diagnostics: {:?}", e);
}
}
fn emit_renderspan(&mut self, sp: &RenderSpan, msg: &str, lvl: Level) {
if let Err(e) = self.emit_(sp, msg, None, lvl) {
panic!("failed to print diagnostics: {:?}", e);
}
}
fn emit_(&mut self,
rsp: &RenderSpan,
msg: &str,
code: Option<&str>,
lvl: Level)
-> io::Result<()> {
let msp = rsp.span();
let primary_span = msp.primary_span();
match code {
Some(code) if self.registry.as_ref()
.and_then(|registry| registry.find_description(code)).is_some() =>
{
let code_with_explain = String::from("--explain ") + code;
print_diagnostic(&mut self.dst, "", lvl, msg, Some(&code_with_explain))?
}
_ => print_diagnostic(&mut self.dst, "", lvl, msg, code)?
}
match *rsp {
FullSpan(_) => {
self.highlight_lines(msp, lvl)?;
if let Some(primary_span) = primary_span {
self.print_macro_backtrace(primary_span)?;
}
}
Suggestion(ref suggestion) => {
self.highlight_suggestion(suggestion)?;
if let Some(primary_span) = primary_span {
self.print_macro_backtrace(primary_span)?;
}
}
FileLine(..) => {
// no source text in this case!
}
}
Ok(())
}
fn highlight_suggestion(&mut self, suggestion: &CodeSuggestion) -> io::Result<()>
{
let primary_span = suggestion.msp.primary_span().unwrap();
let lines = self.cm.span_to_lines(primary_span).unwrap();
assert!(!lines.lines.is_empty());
let complete = suggestion.splice_lines(&self.cm);
let line_count = cmp::min(lines.lines.len(), MAX_HIGHLIGHT_LINES);
let display_lines = &lines.lines[..line_count];
let fm = &*lines.file;
// Calculate the widest number to format evenly
let max_digits = line_num_max_digits(display_lines.last().unwrap());
// print the suggestion without any line numbers, but leave
// space for them. This helps with lining up with previous
// snippets from the actual error being reported.
let mut lines = complete.lines();
for line in lines.by_ref().take(MAX_HIGHLIGHT_LINES) {
write!(&mut self.dst, "{0}:{1:2$} {3}\n",
fm.name, "", max_digits, line)?;
}
// if we elided some lines, add an ellipsis
if let Some(_) = lines.next() {
write!(&mut self.dst, "{0:1$} {0:2$} ...\n",
"", fm.name.len(), max_digits)?;
}
Ok(())
}
fn highlight_lines(&mut self,
msp: &MultiSpan,
lvl: Level)
-> io::Result<()>
{
let mut snippet_data = SnippetData::new(self.cm.clone(),
msp.primary_span());
for span_label in msp.span_labels() {
snippet_data.push(span_label.span,
span_label.is_primary,
span_label.label);
}
let rendered_lines = snippet_data.render_lines();
for rendered_line in &rendered_lines {
for styled_string in &rendered_line.text {
self.dst.apply_style(lvl, &rendered_line.kind, styled_string.style)?;
write!(&mut self.dst, "{}", styled_string.text)?;
self.dst.reset_attrs()?;
}
write!(&mut self.dst, "\n")?;
}
Ok(())
}
fn print_macro_backtrace(&mut self,
sp: Span)
-> io::Result<()> {
for trace in self.cm.macro_backtrace(sp) {
let mut diag_string =
format!("in this expansion of {}", trace.macro_decl_name);
if let Some(def_site_span) = trace.def_site_span {
diag_string.push_str(
&format!(" (defined in {})",
self.cm.span_to_filename(def_site_span)));
}
let snippet = self.cm.span_to_string(sp);
print_diagnostic(&mut self.dst, &snippet, Note, &diag_string, None)?;
}
Ok(())
}
}
fn line_num_max_digits(line: &codemap::LineInfo) -> usize {
let mut max_line_num = line.line_index + 1;
let mut digits = 0;
while max_line_num > 0 {
max_line_num /= 10;
digits += 1;
}
digits
}
fn print_diagnostic(dst: &mut Destination,
topic: &str,
lvl: Level,
msg: &str,
code: Option<&str>)
-> io::Result<()> {
if !topic.is_empty() {
dst.start_attr(term::Attr::ForegroundColor(lvl.color()))?;
write!(dst, "{}: ", topic)?;
dst.reset_attrs()?;
}
dst.start_attr(term::Attr::Bold)?;
dst.start_attr(term::Attr::ForegroundColor(lvl.color()))?;
write!(dst, "{}", lvl.to_string())?;
dst.reset_attrs()?;
write!(dst, ": ")?;
dst.start_attr(term::Attr::Bold)?;
write!(dst, "{}", msg)?;
if let Some(code) = code {
let style = term::Attr::ForegroundColor(term::color::BRIGHT_MAGENTA);
print_maybe_styled!(dst, style, " [{}]", code.clone())?;
}
dst.reset_attrs()?;
write!(dst, "\n")?;
Ok(())
}
#[cfg(unix)]
fn stderr_isatty() -> bool {
use libc;
unsafe { libc::isatty(libc::STDERR_FILENO) != 0 }
}
#[cfg(windows)]
fn stderr_isatty() -> bool {
type DWORD = u32;
type BOOL = i32;
type HANDLE = *mut u8;
const STD_ERROR_HANDLE: DWORD = -12i32 as DWORD;
extern "system" {
fn GetStdHandle(which: DWORD) -> HANDLE;
fn GetConsoleMode(hConsoleHandle: HANDLE,
lpMode: *mut DWORD) -> BOOL;
}
unsafe {
let handle = GetStdHandle(STD_ERROR_HANDLE);
let mut out = 0;
GetConsoleMode(handle, &mut out) != 0
}
}
enum Destination {
Terminal(Box<term::StderrTerminal>),
Raw(Box<Write + Send>),
}
impl Destination {
fn from_stderr() -> Destination {
match term::stderr() {
Some(t) => Terminal(t),
None => Raw(Box::new(io::stderr())),
}
}
fn apply_style(&mut self,
lvl: Level,
_kind: &RenderedLineKind,
style: Style)
-> io::Result<()> {
match style {
Style::FileNameStyle => {
}
Style::LineAndColumn => {
}
Style::LineNumber => {
self.start_attr(term::Attr::Bold)?;
self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_BLUE))?;
}
Style::Quotation => {
}
Style::UnderlinePrimary | Style::LabelPrimary => {
self.start_attr(term::Attr::Bold)?;
self.start_attr(term::Attr::ForegroundColor(lvl.color()))?;
}
Style::UnderlineSecondary | Style::LabelSecondary => {
self.start_attr(term::Attr::Bold)?;
self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_BLUE))?;
}
Style::NoStyle => {
}
}
Ok(())
}
fn start_attr(&mut self, attr: term::Attr) -> io::Result<()> {
match *self {
Terminal(ref mut t) => { t.attr(attr)?; }
Raw(_) => { }
}
Ok(())
}
fn reset_attrs(&mut self) -> io::Result<()> {
match *self {
Terminal(ref mut t) => { t.reset()?; }
Raw(_) => { }
}
Ok(())
}
fn print_maybe_styled(&mut self,
args: fmt::Arguments,
color: term::Attr,
print_newline_at_end: bool)
-> io::Result<()> {
match *self {
Terminal(ref mut t) => {
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.
t.write_fmt(args)?;
t.reset()?;
if print_newline_at_end {
t.write_all(b"\n")
} else {
Ok(())
}
}
Raw(ref mut w) => {
w.write_fmt(args)?;
if print_newline_at_end {
w.write_all(b"\n")
} else {
Ok(())
}
}
}
}
}
impl Write for Destination {
fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
match *self {
Terminal(ref mut t) => t.write(bytes),
Raw(ref mut w) => w.write(bytes),
}
}
fn flush(&mut self) -> io::Result<()> {
match *self {
Terminal(ref mut t) => t.flush(),
Raw(ref mut w) => w.flush(),
}
}
}
#[cfg(test)]
mod test {
use errors::{Level, CodeSuggestion};
use super::EmitterWriter;
use codemap::{mk_sp, CodeMap, Span, MultiSpan, BytePos, NO_EXPANSION};
use std::sync::{Arc, Mutex};
use std::io::{self, Write};
use std::str::from_utf8;
use std::rc::Rc;
struct Sink(Arc<Mutex<Vec<u8>>>);
impl Write for Sink {
fn write(&mut self, data: &[u8]) -> io::Result<usize> {
Write::write(&mut *self.0.lock().unwrap(), data)
}
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
/// Given a string like " ^~~~~~~~~~~~ ", produces a span
/// coverting that range. The idea is that the string has the same
/// length as the input, and we uncover the byte positions. Note
/// that this can span lines and so on.
fn span_from_selection(input: &str, selection: &str) -> Span {
assert_eq!(input.len(), selection.len());
let left_index = selection.find('~').unwrap() as u32;
let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
Span { lo: BytePos(left_index), hi: BytePos(right_index + 1), expn_id: NO_EXPANSION }
}
// Diagnostic doesn't align properly in span where line number increases by one digit
#[test]
fn test_hilight_suggestion_issue_11715() {
let data = Arc::new(Mutex::new(Vec::new()));
let cm = Rc::new(CodeMap::new());
let mut ew = EmitterWriter::new(Box::new(Sink(data.clone())), None, cm.clone());
let content = "abcdefg
koksi
line3
line4
cinq
line6
line7
line8
line9
line10
e-lä-vän
tolv
dreizehn
";
let file = cm.new_filemap_and_lines("dummy.txt", content);
let start = file.lines.borrow()[7];
let end = file.lines.borrow()[11];
let sp = mk_sp(start, end);
let lvl = Level::Error;
println!("highlight_lines");
ew.highlight_lines(&sp.into(), lvl).unwrap();
println!("done");
let vec = data.lock().unwrap().clone();
let vec: &[u8] = &vec;
let str = from_utf8(vec).unwrap();
println!("r#\"\n{}\"#", str);
assert_eq!(str, &r#"
--> dummy.txt:8:1
8 |> line8
|> ^^^^^^^^^^^^^
...
11 |> e-lä-vän
|> ^^^^^^^^^^^^^^^^
"#[1..]);
}
#[test]
fn test_single_span_splice() {
// Test that a `MultiSpan` containing a single span splices a substition correctly
let cm = CodeMap::new();
let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
let selection = " \n ~~\n~~~\n~~~~~ \n \n";
cm.new_filemap_and_lines("blork.rs", inputtext);
let sp = span_from_selection(inputtext, selection);
let msp: MultiSpan = sp.into();
// check that we are extracting the text we thought we were extracting
assert_eq!(&cm.span_to_snippet(sp).unwrap(), "BB\nCCC\nDDDDD");
let substitute = "ZZZZZZ".to_owned();
let expected = "bbbbZZZZZZddddd";
let suggest = CodeSuggestion {
msp: msp,
substitutes: vec![substitute],
};
assert_eq!(suggest.splice_lines(&cm), expected);
}
#[test]
fn test_multi_span_splice() {
// Test that a `MultiSpan` containing multiple spans splices a substition correctly
let cm = CodeMap::new();
let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
let selection1 = " \n \n \n \n ~ \n"; // intentionally out of order
let selection2 = " \n ~~\n~~~\n~~~~~ \n \n";
cm.new_filemap_and_lines("blork.rs", inputtext);
let sp1 = span_from_selection(inputtext, selection1);
let sp2 = span_from_selection(inputtext, selection2);
let msp: MultiSpan = MultiSpan::from_spans(vec![sp1, sp2]);
let expected = "bbbbZZZZZZddddd\neXYZe";
let suggest = CodeSuggestion {
msp: msp,
substitutes: vec!["ZZZZZZ".to_owned(),
"XYZ".to_owned()]
};
assert_eq!(suggest.splice_lines(&cm), expected);
}
#[test]
fn test_multispan_highlight() {
let data = Arc::new(Mutex::new(Vec::new()));
let cm = Rc::new(CodeMap::new());
let mut diag = EmitterWriter::new(Box::new(Sink(data.clone())), None, cm.clone());
let inp = "_____aaaaaa____bbbbbb__cccccdd_";
let sp1 = " ~~~~~~ ";
let sp2 = " ~~~~~~ ";
let sp3 = " ~~~~~ ";
let sp4 = " ~~~~ ";
let sp34 = " ~~~~~~~ ";
let expect_start = &r#"
--> dummy.txt:1:6
1 |> _____aaaaaa____bbbbbb__cccccdd_
|> ^^^^^^ ^^^^^^ ^^^^^^^
"#[1..];
let span = |sp, expected| {
let sp = span_from_selection(inp, sp);
assert_eq!(&cm.span_to_snippet(sp).unwrap(), expected);
sp
};
cm.new_filemap_and_lines("dummy.txt", inp);
let sp1 = span(sp1, "aaaaaa");
let sp2 = span(sp2, "bbbbbb");
let sp3 = span(sp3, "ccccc");
let sp4 = span(sp4, "ccdd");
let sp34 = span(sp34, "cccccdd");
let spans = vec![sp1, sp2, sp3, sp4];
let test = |expected, highlight: &mut FnMut()| {
data.lock().unwrap().clear();
highlight();
let vec = data.lock().unwrap().clone();
let actual = from_utf8(&vec[..]).unwrap();
println!("actual=\n{}", actual);
assert_eq!(actual, expected);
};
let msp = MultiSpan::from_spans(vec![sp1, sp2, sp34]);
test(expect_start, &mut || {
diag.highlight_lines(&msp, Level::Error).unwrap();
});
test(expect_start, &mut || {
let msp = MultiSpan::from_spans(spans.clone());
diag.highlight_lines(&msp, Level::Error).unwrap();
});
}
#[test]
fn test_huge_multispan_highlight() {
let data = Arc::new(Mutex::new(Vec::new()));
let cm = Rc::new(CodeMap::new());
let mut diag = EmitterWriter::new(Box::new(Sink(data.clone())), None, cm.clone());
let inp = "aaaaa\n\
aaaaa\n\
aaaaa\n\
bbbbb\n\
ccccc\n\
xxxxx\n\
yyyyy\n\
_____\n\
ddd__eee_\n\
elided\n\
__f_gg";
let file = cm.new_filemap_and_lines("dummy.txt", inp);
let span = |lo, hi, (off_lo, off_hi)| {
let lines = file.lines.borrow();
let (mut lo, mut hi): (BytePos, BytePos) = (lines[lo], lines[hi]);
lo.0 += off_lo;
hi.0 += off_hi;
mk_sp(lo, hi)
};
let sp0 = span(4, 6, (0, 5));
let sp1 = span(0, 6, (0, 5));
let sp2 = span(8, 8, (0, 3));
let sp3 = span(8, 8, (5, 8));
let sp4 = span(10, 10, (2, 3));
let sp5 = span(10, 10, (4, 6));
let expect0 = &r#"
--> dummy.txt:5:1
5 |> ccccc
|> ^^^^^
...
8 |> _____
9 |> ddd__eee_
|> ^^^ ^^^
10 |> elided
11 |> __f_gg
|> ^ ^^
"#[1..];
let expect = &r#"
--> dummy.txt:1:1
1 |> aaaaa
|> ^^^^^
...
8 |> _____
9 |> ddd__eee_
|> ^^^ ^^^
10 |> elided
11 |> __f_gg
|> ^ ^^
"#[1..];
macro_rules! test {
($expected: expr, $highlight: expr) => ({
data.lock().unwrap().clear();
$highlight();
let vec = data.lock().unwrap().clone();
let actual = from_utf8(&vec[..]).unwrap();
println!("actual:");
println!("{}", actual);
println!("expected:");
println!("{}", $expected);
assert_eq!(&actual[..], &$expected[..]);
});
}
let msp0 = MultiSpan::from_spans(vec![sp0, sp2, sp3, sp4, sp5]);
let msp = MultiSpan::from_spans(vec![sp1, sp2, sp3, sp4, sp5]);
test!(expect0, || {
diag.highlight_lines(&msp0, Level::Error).unwrap();
});
test!(expect, || {
diag.highlight_lines(&msp, Level::Error).unwrap();
});
}
}