src/librustc_errors/lib.rs - third_party/rust - Git at Google

 // 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.

 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
       html_root_url = "https://doc.rust-lang.org/nightly/")]
 #![deny(warnings)]

 #![feature(custom_attribute)]
 #![allow(unused_attributes)]
 #![feature(range_contains)]
 #![cfg_attr(unix, feature(libc))]
 #![feature(conservative_impl_trait)]
 #![feature(i128_type)]

 extern crate term;
 #[cfg(unix)]
 extern crate libc;
 extern crate rustc_data_structures;
 extern crate serialize as rustc_serialize;
 extern crate syntax_pos;
 extern crate unicode_width;

 pub use emitter::ColorConfig;

 use self::Level::*;

 use emitter::{Emitter, EmitterWriter};

 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::stable_hasher::StableHasher;

 use std::borrow::Cow;
 use std::cell::{RefCell, Cell};
 use std::mem;
 use std::rc::Rc;
 use std::{error, fmt};
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering::SeqCst;

 mod diagnostic;
 mod diagnostic_builder;
 pub mod emitter;
 mod snippet;
 pub mod registry;
 mod styled_buffer;
 mod lock;

 use syntax_pos::{BytePos, Loc, FileLinesResult, FileMap, FileName, MultiSpan, Span, NO_EXPANSION};

 #[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
 pub struct CodeSuggestion {
     /// Each substitute can have multiple variants due to multiple
     /// applicable suggestions
     ///
     /// `foo.bar` might be replaced with `a.b` or `x.y` by replacing
     /// `foo` and `bar` on their own:
     ///
     /// ```
     /// vec![
     ///     Substitution { parts: vec![(0..3, "a"), (4..7, "b")] },
     ///     Substitution { parts: vec![(0..3, "x"), (4..7, "y")] },
     /// ]
     /// ```
     ///
     /// or by replacing the entire span:
     ///
     /// ```
     /// vec![
     ///     Substitution { parts: vec![(0..7, "a.b")] },
     ///     Substitution { parts: vec![(0..7, "x.y")] },
     /// ]
     /// ```
     pub substitutions: Vec<Substitution>,
     pub msg: String,
     pub show_code_when_inline: bool,
 }

 #[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
 /// See the docs on `CodeSuggestion::substitutions`
 pub struct Substitution {
     pub parts: Vec<SubstitutionPart>,
 }

 #[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
 pub struct SubstitutionPart {
     pub span: Span,
     pub snippet: String,
 }

 pub trait CodeMapper {
     fn lookup_char_pos(&self, pos: BytePos) -> Loc;
     fn span_to_lines(&self, sp: Span) -> FileLinesResult;
     fn span_to_string(&self, sp: Span) -> String;
     fn span_to_filename(&self, sp: Span) -> FileName;
     fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span>;
     fn call_span_if_macro(&self, sp: Span) -> Span;
     fn ensure_filemap_source_present(&self, file_map: Rc<FileMap>) -> bool;
     fn doctest_offset_line(&self, line: usize) -> usize;
 }

 impl CodeSuggestion {
     /// Returns the assembled code suggestions and whether they should be shown with an underline.
     pub fn splice_lines(&self, cm: &CodeMapper) -> Vec<(String, Vec<SubstitutionPart>)> {
         use syntax_pos::{CharPos, Loc, Pos};

         fn push_trailing(buf: &mut String,
                          line_opt: Option<&Cow<str>>,
                          lo: &Loc,
                          hi_opt: Option<&Loc>) {
             let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(|hi| hi.col.to_usize()));
             if let Some(line) = line_opt {
                 if let Some(lo) = line.char_indices().map(|(i, _)| i).nth(lo) {
                     let hi_opt = hi_opt.and_then(|hi| line.char_indices().map(|(i, _)| i).nth(hi));
                     buf.push_str(match hi_opt {
                         Some(hi) => &line[lo..hi],
                         None => &line[lo..],
                     });
                 }
                 if let None = hi_opt {
                     buf.push('\n');
                 }
             }
         }

         assert!(!self.substitutions.is_empty());

         self.substitutions.iter().cloned().map(|mut substitution| {
             // Assumption: all spans are in the same file, and all spans
             // are disjoint. Sort in ascending order.
             substitution.parts.sort_by_key(|part| part.span.lo());

             // Find the bounding span.
             let lo = substitution.parts.iter().map(|part| part.span.lo()).min().unwrap();
             let hi = substitution.parts.iter().map(|part| part.span.hi()).min().unwrap();
             let bounding_span = Span::new(lo, hi, NO_EXPANSION);
             let lines = cm.span_to_lines(bounding_span).unwrap();
             assert!(!lines.lines.is_empty());

             // To build up the result, we do this for each span:
             // - push the line segment trailing the previous span
             //   (at the beginning a "phantom" span pointing at the start of the line)
             // - push lines between the previous and current span (if any)
             // - if the previous and current span are not on the same line
             //   push the line segment leading up to the current span
             // - splice in the span substitution
             //
             // Finally push the trailing line segment of the last span
             let fm = &lines.file;
             let mut prev_hi = cm.lookup_char_pos(bounding_span.lo());
             prev_hi.col = CharPos::from_usize(0);

             let mut prev_line = fm.get_line(lines.lines[0].line_index);
             let mut buf = String::new();

             for part in &substitution.parts {
                 let cur_lo = cm.lookup_char_pos(part.span.lo());
                 if prev_hi.line == cur_lo.line {
                     push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo));
                 } else {
                     push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
                     // push lines between the previous and current span (if any)
                     for idx in prev_hi.line..(cur_lo.line - 1) {
                         if let Some(line) = fm.get_line(idx) {
                             buf.push_str(line.as_ref());
                             buf.push('\n');
                         }
                     }
                     if let Some(cur_line) = fm.get_line(cur_lo.line - 1) {
                         buf.push_str(&cur_line[..cur_lo.col.to_usize()]);
                     }
                 }
                 buf.push_str(&part.snippet);
                 prev_hi = cm.lookup_char_pos(part.span.hi());
                 prev_line = fm.get_line(prev_hi.line - 1);
             }
             // if the replacement already ends with a newline, don't print the next line
             if !buf.ends_with('\n') {
                 push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
             }
             // remove trailing newlines
             while buf.ends_with('\n') {
                 buf.pop();
             }
             (buf, substitution.parts)
         }).collect()
     }
 }

 /// Used as a return value to signify a fatal error occurred. (It is also
 /// used as the argument to panic at the moment, but that will eventually
 /// not be true.)
 #[derive(Copy, Clone, Debug)]
 #[must_use]
 pub struct FatalError;

 impl fmt::Display for FatalError {
     fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         write!(f, "parser fatal error")
     }
 }

 impl error::Error for FatalError {
     fn description(&self) -> &str {
         "The parser has encountered a fatal error"
     }
 }

 /// Signifies that the compiler died with an explicit call to `.bug`
 /// or `.span_bug` rather than a failed assertion, etc.
 #[derive(Copy, Clone, Debug)]
 pub struct ExplicitBug;

 impl fmt::Display for ExplicitBug {
     fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         write!(f, "parser internal bug")
     }
 }

 impl error::Error for ExplicitBug {
     fn description(&self) -> &str {
         "The parser has encountered an internal bug"
     }
 }

 pub use diagnostic::{Diagnostic, SubDiagnostic, DiagnosticStyledString, DiagnosticId};
 pub use diagnostic_builder::DiagnosticBuilder;

 /// A handler deals with errors; certain errors
 /// (fatal, bug, unimpl) may cause immediate exit,
 /// others log errors for later reporting.
 pub struct Handler {
     pub flags: HandlerFlags,

     err_count: AtomicUsize,
     emitter: RefCell<Box<Emitter>>,
     continue_after_error: Cell<bool>,
     delayed_span_bug: RefCell<Option<Diagnostic>>,
     tracked_diagnostics: RefCell<Option<Vec<Diagnostic>>>,

     // This set contains a hash of every diagnostic that has been emitted by
     // this handler. These hashes is used to avoid emitting the same error
     // twice.
     emitted_diagnostics: RefCell<FxHashSet<u128>>,
 }

 #[derive(Default)]
 pub struct HandlerFlags {
     pub can_emit_warnings: bool,
     pub treat_err_as_bug: bool,
     pub external_macro_backtrace: bool,
 }

 impl Handler {
     pub fn with_tty_emitter(color_config: ColorConfig,
                             can_emit_warnings: bool,
                             treat_err_as_bug: bool,
                             cm: Option<Rc<CodeMapper>>)
                             -> Handler {
         Handler::with_tty_emitter_and_flags(
             color_config,
             cm,
             HandlerFlags {
                 can_emit_warnings,
                 treat_err_as_bug,
                 .. Default::default()
             })
     }

     pub fn with_tty_emitter_and_flags(color_config: ColorConfig,
                                       cm: Option<Rc<CodeMapper>>,
                                       flags: HandlerFlags)
                                       -> Handler {
         let emitter = Box::new(EmitterWriter::stderr(color_config, cm, false));
         Handler::with_emitter_and_flags(emitter, flags)
     }

     pub fn with_emitter(can_emit_warnings: bool,
                         treat_err_as_bug: bool,
                         e: Box<Emitter>)
                         -> Handler {
         Handler::with_emitter_and_flags(
             e,
             HandlerFlags {
                 can_emit_warnings,
                 treat_err_as_bug,
                 .. Default::default()
             })
     }

     pub fn with_emitter_and_flags(e: Box<Emitter>, flags: HandlerFlags) -> Handler {
         Handler {
             flags,
             err_count: AtomicUsize::new(0),
             emitter: RefCell::new(e),
             continue_after_error: Cell::new(true),
             delayed_span_bug: RefCell::new(None),
             tracked_diagnostics: RefCell::new(None),
             emitted_diagnostics: RefCell::new(FxHashSet()),
         }
     }

     pub fn set_continue_after_error(&self, continue_after_error: bool) {
         self.continue_after_error.set(continue_after_error);
     }

     /// Resets the diagnostic error count as well as the cached emitted diagnostics.
     ///
     /// NOTE: DO NOT call this function from rustc. It is only meant to be called from external
     /// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as
     /// the overall count of emitted error diagnostics.
     pub fn reset_err_count(&self) {
         self.emitted_diagnostics.replace(FxHashSet());
         self.err_count.store(0, SeqCst);
     }

     pub fn struct_dummy<'a>(&'a self) -> DiagnosticBuilder<'a> {
         DiagnosticBuilder::new(self, Level::Cancelled, "")
     }

     pub fn struct_span_warn<'a, S: Into<MultiSpan>>(&'a self,
                                                     sp: S,
                                                     msg: &str)
                                                     -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
         result.set_span(sp);
         if !self.flags.can_emit_warnings {
             result.cancel();
         }
         result
     }
     pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(&'a self,
                                                               sp: S,
                                                               msg: &str,
                                                               code: DiagnosticId)
                                                               -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
         result.set_span(sp);
         result.code(code);
         if !self.flags.can_emit_warnings {
             result.cancel();
         }
         result
     }
     pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
         if !self.flags.can_emit_warnings {
             result.cancel();
         }
         result
     }
     pub fn struct_span_err<'a, S: Into<MultiSpan>>(&'a self,
                                                    sp: S,
                                                    msg: &str)
                                                    -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
         result.set_span(sp);
         result
     }
     pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(&'a self,
                                                              sp: S,
                                                              msg: &str,
                                                              code: DiagnosticId)
                                                              -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
         result.set_span(sp);
         result.code(code);
         result
     }
     // FIXME: This method should be removed (every error should have an associated error code).
     pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
         DiagnosticBuilder::new(self, Level::Error, msg)
     }
     pub fn struct_err_with_code<'a>(
         &'a self,
         msg: &str,
         code: DiagnosticId,
     ) -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
         result.code(code);
         result
     }
     pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(&'a self,
                                                      sp: S,
                                                      msg: &str)
                                                      -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Fatal, msg);
         result.set_span(sp);
         result
     }
     pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(&'a self,
                                                                sp: S,
                                                                msg: &str,
                                                                code: DiagnosticId)
                                                                -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Fatal, msg);
         result.set_span(sp);
         result.code(code);
         result
     }
     pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
         DiagnosticBuilder::new(self, Level::Fatal, msg)
     }

     pub fn cancel(&self, err: &mut DiagnosticBuilder) {
         err.cancel();
     }

     fn panic_if_treat_err_as_bug(&self) {
         if self.flags.treat_err_as_bug {
             panic!("encountered error with `-Z treat_err_as_bug");
         }
     }

     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> FatalError {
         self.emit(&sp.into(), msg, Fatal);
         FatalError
     }
     pub fn span_fatal_with_code<S: Into<MultiSpan>>(&self,
                                                     sp: S,
                                                     msg: &str,
                                                     code: DiagnosticId)
                                                     -> FatalError {
         self.emit_with_code(&sp.into(), msg, code, Fatal);
         FatalError
     }
     pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
         self.emit(&sp.into(), msg, Error);
     }
     pub fn mut_span_err<'a, S: Into<MultiSpan>>(&'a self,
                                                 sp: S,
                                                 msg: &str)
                                                 -> DiagnosticBuilder<'a> {
         let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
         result.set_span(sp);
         result
     }
     pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
         self.emit_with_code(&sp.into(), msg, code, Error);
     }
     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
         self.emit(&sp.into(), msg, Warning);
     }
     pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
         self.emit_with_code(&sp.into(), msg, code, Warning);
     }
     pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
         self.emit(&sp.into(), msg, Bug);
         panic!(ExplicitBug);
     }
     pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
         if self.flags.treat_err_as_bug {
             self.span_bug(sp, msg);
         }
         let mut diagnostic = Diagnostic::new(Level::Bug, msg);
         diagnostic.set_span(sp.into());
         *self.delayed_span_bug.borrow_mut() = Some(diagnostic);
     }
     pub fn span_bug_no_panic<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
         self.emit(&sp.into(), msg, Bug);
     }
     pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
         self.emit(&sp.into(), msg, Note);
     }
     pub fn span_note_diag<'a>(&'a self,
                               sp: Span,
                               msg: &str)
                               -> DiagnosticBuilder<'a> {
         let mut db = DiagnosticBuilder::new(self, Note, msg);
         db.set_span(sp);
         db
     }
     pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
         self.span_bug(sp, &format!("unimplemented {}", msg));
     }
     pub fn fatal(&self, msg: &str) -> FatalError {
         if self.flags.treat_err_as_bug {
             self.bug(msg);
         }
         let mut db = DiagnosticBuilder::new(self, Fatal, msg);
         db.emit();
         FatalError
     }
     pub fn err(&self, msg: &str) {
         if self.flags.treat_err_as_bug {
             self.bug(msg);
         }
         let mut db = DiagnosticBuilder::new(self, Error, msg);
         db.emit();
     }
     pub fn warn(&self, msg: &str) {
         let mut db = DiagnosticBuilder::new(self, Warning, msg);
         db.emit();
     }
     pub fn note_without_error(&self, msg: &str) {
         let mut db = DiagnosticBuilder::new(self, Note, msg);
         db.emit();
     }
     pub fn bug(&self, msg: &str) -> ! {
         let mut db = DiagnosticBuilder::new(self, Bug, msg);
         db.emit();
         panic!(ExplicitBug);
     }
     pub fn unimpl(&self, msg: &str) -> ! {
         self.bug(&format!("unimplemented {}", msg));
     }

     fn bump_err_count(&self) {
         self.panic_if_treat_err_as_bug();
         self.err_count.fetch_add(1, SeqCst);
     }

     pub fn err_count(&self) -> usize {
         self.err_count.load(SeqCst)
     }

     pub fn has_errors(&self) -> bool {
         self.err_count() > 0
     }
     pub fn abort_if_errors(&self) {
         let s;
         match self.err_count() {
             0 => {
                 if let Some(bug) = self.delayed_span_bug.borrow_mut().take() {
                     DiagnosticBuilder::new_diagnostic(self, bug).emit();
                 }
                 return;
             }
             1 => s = "aborting due to previous error".to_string(),
             _ => {
                 s = format!("aborting due to {} previous errors", self.err_count());
             }
         }

         panic!(self.fatal(&s));
     }
     pub fn emit(&self, msp: &MultiSpan, msg: &str, lvl: Level) {
         if lvl == Warning && !self.flags.can_emit_warnings {
             return;
         }
         let mut db = DiagnosticBuilder::new(self, lvl, msg);
         db.set_span(msp.clone());
         db.emit();
         if !self.continue_after_error.get() {
             self.abort_if_errors();
         }
     }
     pub fn emit_with_code(&self, msp: &MultiSpan, msg: &str, code: DiagnosticId, lvl: Level) {
         if lvl == Warning && !self.flags.can_emit_warnings {
             return;
         }
         let mut db = DiagnosticBuilder::new_with_code(self, lvl, Some(code), msg);
         db.set_span(msp.clone());
         db.emit();
         if !self.continue_after_error.get() {
             self.abort_if_errors();
         }
     }

     pub fn track_diagnostics<F, R>(&self, f: F) -> (R, Vec<Diagnostic>)
         where F: FnOnce() -> R
     {
         let prev = mem::replace(&mut *self.tracked_diagnostics.borrow_mut(),
                                 Some(Vec::new()));
         let ret = f();
         let diagnostics = mem::replace(&mut *self.tracked_diagnostics.borrow_mut(), prev)
             .unwrap();
         (ret, diagnostics)
     }

     fn emit_db(&self, db: &DiagnosticBuilder) {
         let diagnostic = &**db;

         if let Some(ref mut list) = *self.tracked_diagnostics.borrow_mut() {
             list.push(diagnostic.clone());
         }

         let diagnostic_hash = {
             use std::hash::Hash;
             let mut hasher = StableHasher::new();
             diagnostic.hash(&mut hasher);
             hasher.finish()
         };

         // Only emit the diagnostic if we haven't already emitted an equivalent
         // one:
         if self.emitted_diagnostics.borrow_mut().insert(diagnostic_hash) {
             self.emitter.borrow_mut().emit(db);
             if db.is_error() {
                 self.bump_err_count();
             }
         }
     }
 }


 #[derive(Copy, PartialEq, Clone, Hash, Debug, RustcEncodable, RustcDecodable)]
 pub enum Level {
     Bug,
     Fatal,
     // An error which while not immediately fatal, should stop the compiler
     // progressing beyond the current phase.
     PhaseFatal,
     Error,
     Warning,
     Note,
     Help,
     Cancelled,
 }

 impl fmt::Display for Level {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.to_str().fmt(f)
     }
 }

 impl Level {
     fn color(self) -> term::color::Color {
         match self {
             Bug | Fatal | PhaseFatal | Error => term::color::BRIGHT_RED,
             Warning => {
                 if cfg!(windows) {
                     term::color::BRIGHT_YELLOW
                 } else {
                     term::color::YELLOW
                 }
             }
             Note => term::color::BRIGHT_GREEN,
             Help => term::color::BRIGHT_CYAN,
             Cancelled => unreachable!(),
         }
     }

     pub fn to_str(self) -> &'static str {
         match self {
             Bug => "error: internal compiler error",
             Fatal | PhaseFatal | Error => "error",
             Warning => "warning",
             Note => "note",
             Help => "help",
             Cancelled => panic!("Shouldn't call on cancelled error"),
         }
     }
 }
	// 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.

	#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
	html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
	html_root_url = "https://doc.rust-lang.org/nightly/")]
	#![deny(warnings)]

	#![feature(custom_attribute)]
	#![allow(unused_attributes)]
	#![feature(range_contains)]
	#![cfg_attr(unix, feature(libc))]
	#![feature(conservative_impl_trait)]
	#![feature(i128_type)]

	extern crate term;
	#[cfg(unix)]
	extern crate libc;
	extern crate rustc_data_structures;
	extern crate serialize as rustc_serialize;
	extern crate syntax_pos;
	extern crate unicode_width;

	pub use emitter::ColorConfig;

	use self::Level::*;

	use emitter::{Emitter, EmitterWriter};

	use rustc_data_structures::fx::FxHashSet;
	use rustc_data_structures::stable_hasher::StableHasher;

	use std::borrow::Cow;
	use std::cell::{RefCell, Cell};
	use std::mem;
	use std::rc::Rc;
	use std::{error, fmt};
	use std::sync::atomic::AtomicUsize;
	use std::sync::atomic::Ordering::SeqCst;

	mod diagnostic;
	mod diagnostic_builder;
	pub mod emitter;
	mod snippet;
	pub mod registry;
	mod styled_buffer;
	mod lock;

	use syntax_pos::{BytePos, Loc, FileLinesResult, FileMap, FileName, MultiSpan, Span, NO_EXPANSION};

	#[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
	pub struct CodeSuggestion {
	/// Each substitute can have multiple variants due to multiple
	/// applicable suggestions
	///
	/// `foo.bar` might be replaced with `a.b` or `x.y` by replacing
	/// `foo` and `bar` on their own:
	///
	/// ```
	/// vec![
	/// Substitution { parts: vec![(0..3, "a"), (4..7, "b")] },
	/// Substitution { parts: vec![(0..3, "x"), (4..7, "y")] },
	/// ]
	/// ```
	///
	/// or by replacing the entire span:
	///
	/// ```
	/// vec![
	/// Substitution { parts: vec![(0..7, "a.b")] },
	/// Substitution { parts: vec![(0..7, "x.y")] },
	/// ]
	/// ```
	pub substitutions: Vec<Substitution>,
	pub msg: String,
	pub show_code_when_inline: bool,
	}

	#[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
	/// See the docs on `CodeSuggestion::substitutions`
	pub struct Substitution {
	pub parts: Vec<SubstitutionPart>,
	}

	#[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
	pub struct SubstitutionPart {
	pub span: Span,
	pub snippet: String,
	}

	pub trait CodeMapper {
	fn lookup_char_pos(&self, pos: BytePos) -> Loc;
	fn span_to_lines(&self, sp: Span) -> FileLinesResult;
	fn span_to_string(&self, sp: Span) -> String;
	fn span_to_filename(&self, sp: Span) -> FileName;
	fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span>;
	fn call_span_if_macro(&self, sp: Span) -> Span;
	fn ensure_filemap_source_present(&self, file_map: Rc<FileMap>) -> bool;
	fn doctest_offset_line(&self, line: usize) -> usize;
	}

	impl CodeSuggestion {
	/// Returns the assembled code suggestions and whether they should be shown with an underline.
	pub fn splice_lines(&self, cm: &CodeMapper) -> Vec<(String, Vec<SubstitutionPart>)> {
	use syntax_pos::{CharPos, Loc, Pos};

	fn push_trailing(buf: &mut String,
	line_opt: Option<&Cow<str>>,
	lo: &Loc,
	hi_opt: Option<&Loc>) {
	let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(\|hi\| hi.col.to_usize()));
	if let Some(line) = line_opt {
	if let Some(lo) = line.char_indices().map(\|(i, _)\| i).nth(lo) {
	let hi_opt = hi_opt.and_then(\|hi\| line.char_indices().map(\|(i, _)\| i).nth(hi));
	buf.push_str(match hi_opt {
	Some(hi) => &line[lo..hi],
	None => &line[lo..],
	});
	}
	if let None = hi_opt {
	buf.push('\n');
	}
	}
	}

	assert!(!self.substitutions.is_empty());

	self.substitutions.iter().cloned().map(\|mut substitution\| {
	// Assumption: all spans are in the same file, and all spans
	// are disjoint. Sort in ascending order.
	substitution.parts.sort_by_key(\|part\| part.span.lo());

	// Find the bounding span.
	let lo = substitution.parts.iter().map(\|part\| part.span.lo()).min().unwrap();
	let hi = substitution.parts.iter().map(\|part\| part.span.hi()).min().unwrap();
	let bounding_span = Span::new(lo, hi, NO_EXPANSION);
	let lines = cm.span_to_lines(bounding_span).unwrap();
	assert!(!lines.lines.is_empty());

	// To build up the result, we do this for each span:
	// - push the line segment trailing the previous span
	// (at the beginning a "phantom" span pointing at the start of the line)
	// - push lines between the previous and current span (if any)
	// - if the previous and current span are not on the same line
	// push the line segment leading up to the current span
	// - splice in the span substitution
	//
	// Finally push the trailing line segment of the last span
	let fm = &lines.file;
	let mut prev_hi = cm.lookup_char_pos(bounding_span.lo());
	prev_hi.col = CharPos::from_usize(0);

	let mut prev_line = fm.get_line(lines.lines[0].line_index);
	let mut buf = String::new();

	for part in &substitution.parts {
	let cur_lo = cm.lookup_char_pos(part.span.lo());
	if prev_hi.line == cur_lo.line {
	push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo));
	} else {
	push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
	// push lines between the previous and current span (if any)
	for idx in prev_hi.line..(cur_lo.line - 1) {
	if let Some(line) = fm.get_line(idx) {
	buf.push_str(line.as_ref());
	buf.push('\n');
	}
	}
	if let Some(cur_line) = fm.get_line(cur_lo.line - 1) {
	buf.push_str(&cur_line[..cur_lo.col.to_usize()]);
	}
	}
	buf.push_str(&part.snippet);
	prev_hi = cm.lookup_char_pos(part.span.hi());
	prev_line = fm.get_line(prev_hi.line - 1);
	}
	// if the replacement already ends with a newline, don't print the next line
	if !buf.ends_with('\n') {
	push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
	}
	// remove trailing newlines
	while buf.ends_with('\n') {
	buf.pop();
	}
	(buf, substitution.parts)
	}).collect()
	}
	}

	/// Used as a return value to signify a fatal error occurred. (It is also
	/// used as the argument to panic at the moment, but that will eventually
	/// not be true.)
	#[derive(Copy, Clone, Debug)]
	#[must_use]
	pub struct FatalError;

	impl fmt::Display for FatalError {
	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
	write!(f, "parser fatal error")
	}
	}

	impl error::Error for FatalError {
	fn description(&self) -> &str {
	"The parser has encountered a fatal error"
	}
	}

	/// Signifies that the compiler died with an explicit call to `.bug`
	/// or `.span_bug` rather than a failed assertion, etc.
	#[derive(Copy, Clone, Debug)]
	pub struct ExplicitBug;

	impl fmt::Display for ExplicitBug {
	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
	write!(f, "parser internal bug")
	}
	}

	impl error::Error for ExplicitBug {
	fn description(&self) -> &str {
	"The parser has encountered an internal bug"
	}
	}

	pub use diagnostic::{Diagnostic, SubDiagnostic, DiagnosticStyledString, DiagnosticId};
	pub use diagnostic_builder::DiagnosticBuilder;

	/// A handler deals with errors; certain errors
	/// (fatal, bug, unimpl) may cause immediate exit,
	/// others log errors for later reporting.
	pub struct Handler {
	pub flags: HandlerFlags,

	err_count: AtomicUsize,
	emitter: RefCell<Box<Emitter>>,
	continue_after_error: Cell<bool>,
	delayed_span_bug: RefCell<Option<Diagnostic>>,
	tracked_diagnostics: RefCell<Option<Vec<Diagnostic>>>,

	// This set contains a hash of every diagnostic that has been emitted by
	// this handler. These hashes is used to avoid emitting the same error
	// twice.
	emitted_diagnostics: RefCell<FxHashSet<u128>>,
	}

	#[derive(Default)]
	pub struct HandlerFlags {
	pub can_emit_warnings: bool,
	pub treat_err_as_bug: bool,
	pub external_macro_backtrace: bool,
	}

	impl Handler {
	pub fn with_tty_emitter(color_config: ColorConfig,
	can_emit_warnings: bool,
	treat_err_as_bug: bool,
	cm: Option<Rc<CodeMapper>>)
	-> Handler {
	Handler::with_tty_emitter_and_flags(
	color_config,
	cm,
	HandlerFlags {
	can_emit_warnings,
	treat_err_as_bug,
	.. Default::default()
	})
	}

	pub fn with_tty_emitter_and_flags(color_config: ColorConfig,
	cm: Option<Rc<CodeMapper>>,
	flags: HandlerFlags)
	-> Handler {
	let emitter = Box::new(EmitterWriter::stderr(color_config, cm, false));
	Handler::with_emitter_and_flags(emitter, flags)
	}

	pub fn with_emitter(can_emit_warnings: bool,
	treat_err_as_bug: bool,
	e: Box<Emitter>)
	-> Handler {
	Handler::with_emitter_and_flags(
	e,
	HandlerFlags {
	can_emit_warnings,
	treat_err_as_bug,
	.. Default::default()
	})
	}

	pub fn with_emitter_and_flags(e: Box<Emitter>, flags: HandlerFlags) -> Handler {
	Handler {
	flags,
	err_count: AtomicUsize::new(0),
	emitter: RefCell::new(e),
	continue_after_error: Cell::new(true),
	delayed_span_bug: RefCell::new(None),
	tracked_diagnostics: RefCell::new(None),
	emitted_diagnostics: RefCell::new(FxHashSet()),
	}
	}

	pub fn set_continue_after_error(&self, continue_after_error: bool) {
	self.continue_after_error.set(continue_after_error);
	}

	/// Resets the diagnostic error count as well as the cached emitted diagnostics.
	///
	/// NOTE: DO NOT call this function from rustc. It is only meant to be called from external
	/// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as
	/// the overall count of emitted error diagnostics.
	pub fn reset_err_count(&self) {
	self.emitted_diagnostics.replace(FxHashSet());
	self.err_count.store(0, SeqCst);
	}

	pub fn struct_dummy<'a>(&'a self) -> DiagnosticBuilder<'a> {
	DiagnosticBuilder::new(self, Level::Cancelled, "")
	}

	pub fn struct_span_warn<'a, S: Into<MultiSpan>>(&'a self,
	sp: S,
	msg: &str)
	-> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
	result.set_span(sp);
	if !self.flags.can_emit_warnings {
	result.cancel();
	}
	result
	}
	pub fn struct_span_warn_with_code<'a, S: Into<MultiSpan>>(&'a self,
	sp: S,
	msg: &str,
	code: DiagnosticId)
	-> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
	result.set_span(sp);
	result.code(code);
	if !self.flags.can_emit_warnings {
	result.cancel();
	}
	result
	}
	pub fn struct_warn<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
	if !self.flags.can_emit_warnings {
	result.cancel();
	}
	result
	}
	pub fn struct_span_err<'a, S: Into<MultiSpan>>(&'a self,
	sp: S,
	msg: &str)
	-> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
	result.set_span(sp);
	result
	}
	pub fn struct_span_err_with_code<'a, S: Into<MultiSpan>>(&'a self,
	sp: S,
	msg: &str,
	code: DiagnosticId)
	-> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
	result.set_span(sp);
	result.code(code);
	result
	}
	// FIXME: This method should be removed (every error should have an associated error code).
	pub fn struct_err<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
	DiagnosticBuilder::new(self, Level::Error, msg)
	}
	pub fn struct_err_with_code<'a>(
	&'a self,
	msg: &str,
	code: DiagnosticId,
	) -> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
	result.code(code);
	result
	}
	pub fn struct_span_fatal<'a, S: Into<MultiSpan>>(&'a self,
	sp: S,
	msg: &str)
	-> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Fatal, msg);
	result.set_span(sp);
	result
	}
	pub fn struct_span_fatal_with_code<'a, S: Into<MultiSpan>>(&'a self,
	sp: S,
	msg: &str,
	code: DiagnosticId)
	-> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Fatal, msg);
	result.set_span(sp);
	result.code(code);
	result
	}
	pub fn struct_fatal<'a>(&'a self, msg: &str) -> DiagnosticBuilder<'a> {
	DiagnosticBuilder::new(self, Level::Fatal, msg)
	}

	pub fn cancel(&self, err: &mut DiagnosticBuilder) {
	err.cancel();
	}

	fn panic_if_treat_err_as_bug(&self) {
	if self.flags.treat_err_as_bug {
	panic!("encountered error with `-Z treat_err_as_bug");
	}
	}

	pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> FatalError {
	self.emit(&sp.into(), msg, Fatal);
	FatalError
	}
	pub fn span_fatal_with_code<S: Into<MultiSpan>>(&self,
	sp: S,
	msg: &str,
	code: DiagnosticId)
	-> FatalError {
	self.emit_with_code(&sp.into(), msg, code, Fatal);
	FatalError
	}
	pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
	self.emit(&sp.into(), msg, Error);
	}
	pub fn mut_span_err<'a, S: Into<MultiSpan>>(&'a self,
	sp: S,
	msg: &str)
	-> DiagnosticBuilder<'a> {
	let mut result = DiagnosticBuilder::new(self, Level::Error, msg);
	result.set_span(sp);
	result
	}
	pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
	self.emit_with_code(&sp.into(), msg, code, Error);
	}
	pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
	self.emit(&sp.into(), msg, Warning);
	}
	pub fn span_warn_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
	self.emit_with_code(&sp.into(), msg, code, Warning);
	}
	pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
	self.emit(&sp.into(), msg, Bug);
	panic!(ExplicitBug);
	}
	pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
	if self.flags.treat_err_as_bug {
	self.span_bug(sp, msg);
	}
	let mut diagnostic = Diagnostic::new(Level::Bug, msg);
	diagnostic.set_span(sp.into());
	*self.delayed_span_bug.borrow_mut() = Some(diagnostic);
	}
	pub fn span_bug_no_panic<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
	self.emit(&sp.into(), msg, Bug);
	}
	pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
	self.emit(&sp.into(), msg, Note);
	}
	pub fn span_note_diag<'a>(&'a self,
	sp: Span,
	msg: &str)
	-> DiagnosticBuilder<'a> {
	let mut db = DiagnosticBuilder::new(self, Note, msg);
	db.set_span(sp);
	db
	}
	pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
	self.span_bug(sp, &format!("unimplemented {}", msg));
	}
	pub fn fatal(&self, msg: &str) -> FatalError {
	if self.flags.treat_err_as_bug {
	self.bug(msg);
	}
	let mut db = DiagnosticBuilder::new(self, Fatal, msg);
	db.emit();
	FatalError
	}
	pub fn err(&self, msg: &str) {
	if self.flags.treat_err_as_bug {
	self.bug(msg);
	}
	let mut db = DiagnosticBuilder::new(self, Error, msg);
	db.emit();
	}
	pub fn warn(&self, msg: &str) {
	let mut db = DiagnosticBuilder::new(self, Warning, msg);
	db.emit();
	}
	pub fn note_without_error(&self, msg: &str) {
	let mut db = DiagnosticBuilder::new(self, Note, msg);
	db.emit();
	}
	pub fn bug(&self, msg: &str) -> ! {
	let mut db = DiagnosticBuilder::new(self, Bug, msg);
	db.emit();
	panic!(ExplicitBug);
	}
	pub fn unimpl(&self, msg: &str) -> ! {
	self.bug(&format!("unimplemented {}", msg));
	}

	fn bump_err_count(&self) {
	self.panic_if_treat_err_as_bug();
	self.err_count.fetch_add(1, SeqCst);
	}

	pub fn err_count(&self) -> usize {
	self.err_count.load(SeqCst)
	}

	pub fn has_errors(&self) -> bool {
	self.err_count() > 0
	}
	pub fn abort_if_errors(&self) {
	let s;
	match self.err_count() {
	0 => {
	if let Some(bug) = self.delayed_span_bug.borrow_mut().take() {
	DiagnosticBuilder::new_diagnostic(self, bug).emit();
	}
	return;
	}
	1 => s = "aborting due to previous error".to_string(),
	_ => {
	s = format!("aborting due to {} previous errors", self.err_count());
	}
	}

	panic!(self.fatal(&s));
	}
	pub fn emit(&self, msp: &MultiSpan, msg: &str, lvl: Level) {
	if lvl == Warning && !self.flags.can_emit_warnings {
	return;
	}
	let mut db = DiagnosticBuilder::new(self, lvl, msg);
	db.set_span(msp.clone());
	db.emit();
	if !self.continue_after_error.get() {
	self.abort_if_errors();
	}
	}
	pub fn emit_with_code(&self, msp: &MultiSpan, msg: &str, code: DiagnosticId, lvl: Level) {
	if lvl == Warning && !self.flags.can_emit_warnings {
	return;
	}
	let mut db = DiagnosticBuilder::new_with_code(self, lvl, Some(code), msg);
	db.set_span(msp.clone());
	db.emit();
	if !self.continue_after_error.get() {
	self.abort_if_errors();
	}
	}

	pub fn track_diagnostics<F, R>(&self, f: F) -> (R, Vec<Diagnostic>)
	where F: FnOnce() -> R
	{
	let prev = mem::replace(&mut *self.tracked_diagnostics.borrow_mut(),
	Some(Vec::new()));
	let ret = f();
	let diagnostics = mem::replace(&mut *self.tracked_diagnostics.borrow_mut(), prev)
	.unwrap();
	(ret, diagnostics)
	}

	fn emit_db(&self, db: &DiagnosticBuilder) {
	let diagnostic = &**db;

	if let Some(ref mut list) = *self.tracked_diagnostics.borrow_mut() {
	list.push(diagnostic.clone());
	}

	let diagnostic_hash = {
	use std::hash::Hash;
	let mut hasher = StableHasher::new();
	diagnostic.hash(&mut hasher);
	hasher.finish()
	};

	// Only emit the diagnostic if we haven't already emitted an equivalent
	// one:
	if self.emitted_diagnostics.borrow_mut().insert(diagnostic_hash) {
	self.emitter.borrow_mut().emit(db);
	if db.is_error() {
	self.bump_err_count();
	}
	}
	}
	}


	#[derive(Copy, PartialEq, Clone, Hash, Debug, RustcEncodable, RustcDecodable)]
	pub enum Level {
	Bug,
	Fatal,
	// An error which while not immediately fatal, should stop the compiler
	// progressing beyond the current phase.
	PhaseFatal,
	Error,
	Warning,
	Note,
	Help,
	Cancelled,
	}

	impl fmt::Display for Level {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	self.to_str().fmt(f)
	}
	}

	impl Level {
	fn color(self) -> term::color::Color {
	match self {
	Bug \| Fatal \| PhaseFatal \| Error => term::color::BRIGHT_RED,
	Warning => {
	if cfg!(windows) {
	term::color::BRIGHT_YELLOW
	} else {
	term::color::YELLOW
	}
	}
	Note => term::color::BRIGHT_GREEN,
	Help => term::color::BRIGHT_CYAN,
	Cancelled => unreachable!(),
	}
	}

	pub fn to_str(self) -> &'static str {
	match self {
	Bug => "error: internal compiler error",
	Fatal \| PhaseFatal \| Error => "error",
	Warning => "warning",
	Note => "note",
	Help => "help",
	Cancelled => panic!("Shouldn't call on cancelled error"),
	}
	}
	}