// 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 Diagnostic;
use DiagnosticId;
use DiagnosticStyledString;
use Applicability;
use Level;
use Handler;
use std::fmt::{self, Debug};
use std::ops::{Deref, DerefMut};
use std::thread::panicking;
use syntax_pos::{MultiSpan, Span};
/// Used for emitting structured error messages and other diagnostic information.
#[must_use]
#[derive(Clone)]
pub struct DiagnosticBuilder<'a> {
pub handler: &'a Handler,
diagnostic: Diagnostic,
allow_suggestions: bool,
}
/// In general, the `DiagnosticBuilder` uses deref to allow access to
/// the fields and methods of the embedded `diagnostic` in a
/// transparent way. *However,* many of the methods are intended to
/// be used in a chained way, and hence ought to return `self`. In
/// that case, we can't just naively forward to the method on the
/// `diagnostic`, because the return type would be a `&Diagnostic`
/// instead of a `&DiagnosticBuilder<'a>`. This `forward!` macro makes
/// it easy to declare such methods on the builder.
macro_rules! forward {
// Forward pattern for &self -> &Self
(pub fn $n:ident(&self, $($name:ident: $ty:ty),*) -> &Self) => {
pub fn $n(&self, $($name: $ty),*) -> &Self {
self.diagnostic.$n($($name),*);
self
}
};
// Forward pattern for &mut self -> &mut Self
(pub fn $n:ident(&mut self, $($name:ident: $ty:ty),*) -> &mut Self) => {
pub fn $n(&mut self, $($name: $ty),*) -> &mut Self {
self.diagnostic.$n($($name),*);
self
}
};
// Forward pattern for &mut self -> &mut Self, with S: Into<MultiSpan>
// type parameter. No obvious way to make this more generic.
(pub fn $n:ident<S: Into<MultiSpan>>(&mut self, $($name:ident: $ty:ty),*) -> &mut Self) => {
pub fn $n<S: Into<MultiSpan>>(&mut self, $($name: $ty),*) -> &mut Self {
self.diagnostic.$n($($name),*);
self
}
};
}
impl<'a> Deref for DiagnosticBuilder<'a> {
type Target = Diagnostic;
fn deref(&self) -> &Diagnostic {
&self.diagnostic
}
}
impl<'a> DerefMut for DiagnosticBuilder<'a> {
fn deref_mut(&mut self) -> &mut Diagnostic {
&mut self.diagnostic
}
}
impl<'a> DiagnosticBuilder<'a> {
/// Emit the diagnostic.
pub fn emit(&mut self) {
if self.cancelled() {
return;
}
self.handler.emit_db(&self);
self.cancel();
}
/// Buffers the diagnostic for later emission.
pub fn buffer(self, buffered_diagnostics: &mut Vec<Diagnostic>) {
// We need to use `ptr::read` because `DiagnosticBuilder`
// implements `Drop`.
let diagnostic;
unsafe {
diagnostic = ::std::ptr::read(&self.diagnostic);
::std::mem::forget(self);
};
buffered_diagnostics.push(diagnostic);
}
/// Convenience function for internal use, clients should use one of the
/// span_* methods instead.
pub fn sub<S: Into<MultiSpan>>(
&mut self,
level: Level,
message: &str,
span: Option<S>,
) -> &mut Self {
let span = span.map(|s| s.into()).unwrap_or(MultiSpan::new());
self.diagnostic.sub(level, message, span, None);
self
}
/// Delay emission of this diagnostic as a bug.
///
/// This can be useful in contexts where an error indicates a bug but
/// typically this only happens when other compilation errors have already
/// happened. In those cases this can be used to defer emission of this
/// diagnostic as a bug in the compiler only if no other errors have been
/// emitted.
///
/// In the meantime, though, callsites are required to deal with the "bug"
/// locally in whichever way makes the most sense.
pub fn delay_as_bug(&mut self) {
self.level = Level::Bug;
self.handler.delay_as_bug(self.diagnostic.clone());
self.cancel();
}
/// Add a span/label to be included in the resulting snippet.
/// This is pushed onto the `MultiSpan` that was created when the
/// diagnostic was first built. If you don't call this function at
/// all, and you just supplied a `Span` to create the diagnostic,
/// then the snippet will just include that `Span`, which is
/// called the primary span.
pub fn span_label<T: Into<String>>(&mut self, span: Span, label: T) -> &mut Self {
self.diagnostic.span_label(span, label);
self
}
forward!(pub fn note_expected_found(&mut self,
label: &dyn fmt::Display,
expected: DiagnosticStyledString,
found: DiagnosticStyledString)
-> &mut Self);
forward!(pub fn note_expected_found_extra(&mut self,
label: &dyn fmt::Display,
expected: DiagnosticStyledString,
found: DiagnosticStyledString,
expected_extra: &dyn fmt::Display,
found_extra: &dyn fmt::Display)
-> &mut Self);
forward!(pub fn note(&mut self, msg: &str) -> &mut Self);
forward!(pub fn span_note<S: Into<MultiSpan>>(&mut self,
sp: S,
msg: &str)
-> &mut Self);
forward!(pub fn warn(&mut self, msg: &str) -> &mut Self);
forward!(pub fn span_warn<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self);
forward!(pub fn help(&mut self , msg: &str) -> &mut Self);
forward!(pub fn span_help<S: Into<MultiSpan>>(&mut self,
sp: S,
msg: &str)
-> &mut Self);
forward!(pub fn span_suggestion_short(&mut self,
sp: Span,
msg: &str,
suggestion: String)
-> &mut Self);
forward!(pub fn multipart_suggestion(
&mut self,
msg: &str,
suggestion: Vec<(Span, String)>
) -> &mut Self);
forward!(pub fn span_suggestion(&mut self,
sp: Span,
msg: &str,
suggestion: String)
-> &mut Self);
forward!(pub fn span_suggestions(&mut self,
sp: Span,
msg: &str,
suggestions: Vec<String>)
-> &mut Self);
pub fn span_suggestion_with_applicability(&mut self,
sp: Span,
msg: &str,
suggestion: String,
applicability: Applicability)
-> &mut Self {
if !self.allow_suggestions {
return self
}
self.diagnostic.span_suggestion_with_applicability(
sp,
msg,
suggestion,
applicability,
);
self
}
pub fn span_suggestions_with_applicability(&mut self,
sp: Span,
msg: &str,
suggestions: Vec<String>,
applicability: Applicability)
-> &mut Self {
if !self.allow_suggestions {
return self
}
self.diagnostic.span_suggestions_with_applicability(
sp,
msg,
suggestions,
applicability,
);
self
}
pub fn span_suggestion_short_with_applicability(&mut self,
sp: Span,
msg: &str,
suggestion: String,
applicability: Applicability)
-> &mut Self {
if !self.allow_suggestions {
return self
}
self.diagnostic.span_suggestion_short_with_applicability(
sp,
msg,
suggestion,
applicability,
);
self
}
forward!(pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self);
forward!(pub fn code(&mut self, s: DiagnosticId) -> &mut Self);
pub fn allow_suggestions(&mut self, allow: bool) -> &mut Self {
self.allow_suggestions = allow;
self
}
/// Convenience function for internal use, clients should use one of the
/// struct_* methods on Handler.
pub fn new(handler: &'a Handler, level: Level, message: &str) -> DiagnosticBuilder<'a> {
DiagnosticBuilder::new_with_code(handler, level, None, message)
}
/// Convenience function for internal use, clients should use one of the
/// struct_* methods on Handler.
pub fn new_with_code(handler: &'a Handler,
level: Level,
code: Option<DiagnosticId>,
message: &str)
-> DiagnosticBuilder<'a> {
let diagnostic = Diagnostic::new_with_code(level, code, message);
DiagnosticBuilder::new_diagnostic(handler, diagnostic)
}
/// Creates a new `DiagnosticBuilder` with an already constructed
/// diagnostic.
pub fn new_diagnostic(handler: &'a Handler, diagnostic: Diagnostic)
-> DiagnosticBuilder<'a> {
DiagnosticBuilder {
handler,
diagnostic,
allow_suggestions: true,
}
}
}
impl<'a> Debug for DiagnosticBuilder<'a> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.diagnostic.fmt(f)
}
}
/// Destructor bomb - a `DiagnosticBuilder` must be either emitted or canceled
/// or we emit a bug.
impl<'a> Drop for DiagnosticBuilder<'a> {
fn drop(&mut self) {
if !panicking() && !self.cancelled() {
let mut db = DiagnosticBuilder::new(self.handler,
Level::Bug,
"Error constructed but not emitted");
db.emit();
panic!();
}
}
}