swc_common/errors/
diagnostic_builder.rs

1// Copyright 2012-2015 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.
4//
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.
10
11use std::{
12    fmt::{self, Debug},
13    ops::{Deref, DerefMut},
14    thread::panicking,
15};
16
17use tracing::debug;
18
19use super::{Applicability, Diagnostic, DiagnosticId, DiagnosticStyledString, Handler, Level};
20use crate::syntax_pos::{MultiSpan, Span};
21
22/// Used for emitting structured error messages and other diagnostic
23/// information.
24///
25/// If there is some state in a downstream crate you would like to
26/// access in the methods of `DiagnosticBuilder` here, consider
27/// extending `HandlerFlags`, accessed via `self.handler.flags`.
28#[must_use]
29#[derive(Clone)]
30pub struct DiagnosticBuilder<'a> {
31    pub handler: &'a Handler,
32    #[cfg(not(feature = "__plugin_mode"))]
33    pub(crate) diagnostic: Box<Diagnostic>,
34    #[cfg(feature = "__plugin_mode")]
35    pub diagnostic: Box<Diagnostic>,
36    allow_suggestions: bool,
37}
38
39/// In general, the `DiagnosticBuilder` uses deref to allow access to
40/// the fields and methods of the embedded `diagnostic` in a
41/// transparent way.  *However,* many of the methods are intended to
42/// be used in a chained way, and hence ought to return `self`. In
43/// that case, we can't just naively forward to the method on the
44/// `diagnostic`, because the return type would be a `&Diagnostic`
45/// instead of a `&DiagnosticBuilder<'a>`. This `forward!` macro makes
46/// it easy to declare such methods on the builder.
47#[allow(unused)]
48macro_rules! forward {
49    // Forward pattern for &self -> &Self
50    (pub fn $n:ident(&self, $($name:ident: $ty:ty),* $(,)*) -> &Self) => {
51        pub fn $n(&self, $($name: $ty),*) -> &Self {
52            #[allow(deprecated)]
53            self.diagnostic.$n($($name),*);
54            self
55        }
56    };
57
58    // Forward pattern for &mut self -> &mut Self
59    (pub fn $n:ident(&mut self, $($name:ident: $ty:ty),* $(,)*) -> &mut Self) => {
60        pub fn $n(&mut self, $($name: $ty),*) -> &mut Self {
61            #[allow(deprecated)]
62            self.diagnostic.$n($($name),*);
63            self
64        }
65    };
66
67    // Forward pattern for &mut self -> &mut Self, with S: Into<MultiSpan>
68    // type parameter. No obvious way to make this more generic.
69    (pub fn $n:ident<S: Into<MultiSpan>>(
70                    &mut self,
71                    $($name:ident: $ty:ty),*
72                    $(,)*) -> &mut Self) => {
73        pub fn $n<S: Into<MultiSpan>>(&mut self, $($name: $ty),*) -> &mut Self {
74            #[allow(deprecated)]
75            self.diagnostic.$n($($name),*);
76            self
77        }
78    };
79}
80
81impl Deref for DiagnosticBuilder<'_> {
82    type Target = Diagnostic;
83
84    fn deref(&self) -> &Diagnostic {
85        &self.diagnostic
86    }
87}
88
89impl DerefMut for DiagnosticBuilder<'_> {
90    fn deref_mut(&mut self) -> &mut Diagnostic {
91        &mut self.diagnostic
92    }
93}
94
95impl<'a> DiagnosticBuilder<'a> {
96    forward!(pub fn note_expected_found(&mut self,
97                                        label: &dyn fmt::Display,
98                                        expected: DiagnosticStyledString,
99                                        found: DiagnosticStyledString,
100                                        ) -> &mut Self);
101
102    forward!(pub fn note_expected_found_extra(&mut self,
103                                              label: &dyn fmt::Display,
104                                              expected: DiagnosticStyledString,
105                                              found: DiagnosticStyledString,
106                                              expected_extra: &dyn fmt::Display,
107                                              found_extra: &dyn fmt::Display,
108                                              ) -> &mut Self);
109
110    forward!(pub fn note(&mut self, msg: &str) -> &mut Self);
111
112    forward!(pub fn span_note<S: Into<MultiSpan>>(&mut self,
113                                                  sp: S,
114                                                  msg: &str,
115                                                  ) -> &mut Self);
116
117    forward!(pub fn warn(&mut self, msg: &str) -> &mut Self);
118
119    forward!(pub fn span_warn<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self);
120
121    forward!(pub fn help(&mut self , msg: &str) -> &mut Self);
122
123    forward!(pub fn span_help<S: Into<MultiSpan>>(&mut self,
124                                                  sp: S,
125                                                  msg: &str,
126                                                  ) -> &mut Self);
127
128    forward!(pub fn span_suggestion_short(
129                                      &mut self,
130                                      sp: Span,
131                                      msg: &str,
132                                      suggestion: String,
133                                      ) -> &mut Self);
134
135    forward!(pub fn multipart_suggestion(
136        &mut self,
137        msg: &str,
138        suggestion: Vec<(Span, String)>,
139    ) -> &mut Self);
140
141    forward!(pub fn span_suggestion(&mut self,
142                                    sp: Span,
143                                    msg: &str,
144                                    suggestion: String,
145                                    ) -> &mut Self);
146
147    forward!(pub fn span_suggestions(&mut self,
148                                     sp: Span,
149                                     msg: &str,
150                                     suggestions: Vec<String>,
151                                     ) -> &mut Self);
152
153    forward!(pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self);
154
155    forward!(pub fn code(&mut self, s: DiagnosticId) -> &mut Self);
156
157    /// Emit the diagnostic.
158    pub fn emit(&mut self) {
159        if self.cancelled() {
160            return;
161        }
162
163        self.handler.emit_db(self);
164        self.cancel();
165    }
166
167    /// Buffers the diagnostic for later emission, unless handler
168    /// has disabled such buffering.
169    pub fn buffer(mut self, buffered_diagnostics: &mut Vec<Diagnostic>) {
170        if self.handler.flags.dont_buffer_diagnostics || self.handler.flags.treat_err_as_bug {
171            self.emit();
172            return;
173        }
174
175        // We need to use `ptr::read` because `DiagnosticBuilder`
176        // implements `Drop`.
177        let diagnostic;
178        unsafe {
179            diagnostic = ::std::ptr::read(&self.diagnostic);
180            ::std::mem::forget(self);
181        };
182        // Logging here is useful to help track down where in logs an error was
183        // actually emitted.
184        if cfg!(feature = "debug") {
185            #[cfg(debug_assertions)]
186            debug!("buffer: diagnostic={:?}", diagnostic);
187        }
188        buffered_diagnostics.push(*diagnostic);
189    }
190
191    /// Convenience function for internal use, clients should use one of the
192    /// span_* methods instead.
193    pub fn sub<S: Into<MultiSpan>>(
194        &mut self,
195        level: Level,
196        message: &str,
197        span: Option<S>,
198    ) -> &mut Self {
199        let span = span.map(|s| s.into()).unwrap_or_default();
200        self.diagnostic.sub(level, message, span, None);
201        self
202    }
203
204    /// Delay emission of this diagnostic as a bug.
205    ///
206    /// This can be useful in contexts where an error indicates a bug but
207    /// typically this only happens when other compilation errors have already
208    /// happened. In those cases this can be used to defer emission of this
209    /// diagnostic as a bug in the compiler only if no other errors have been
210    /// emitted.
211    ///
212    /// In the meantime, though, callsites are required to deal with the "bug"
213    /// locally in whichever way makes the most sense.
214    pub fn delay_as_bug(&mut self) {
215        self.level = Level::Bug;
216        self.handler.delay_as_bug(*self.diagnostic.clone());
217        self.cancel();
218    }
219
220    /// Add a span/label to be included in the resulting snippet.
221    /// This is pushed onto the `MultiSpan` that was created when the
222    /// diagnostic was first built. If you don't call this function at
223    /// all, and you just supplied a `Span` to create the diagnostic,
224    /// then the snippet will just include that `Span`, which is
225    /// called the primary span.
226    pub fn span_label<T: Into<String>>(&mut self, span: Span, label: T) -> &mut Self {
227        self.diagnostic.span_label(span, label);
228        self
229    }
230
231    pub fn multipart_suggestion_with_applicability(
232        &mut self,
233        msg: &str,
234        suggestion: Vec<(Span, String)>,
235        applicability: Applicability,
236    ) -> &mut Self {
237        if !self.allow_suggestions {
238            return self;
239        }
240        self.diagnostic
241            .multipart_suggestion_with_applicability(msg, suggestion, applicability);
242        self
243    }
244
245    pub fn span_suggestion_with_applicability(
246        &mut self,
247        sp: Span,
248        msg: &str,
249        suggestion: String,
250        applicability: Applicability,
251    ) -> &mut Self {
252        if !self.allow_suggestions {
253            return self;
254        }
255        self.diagnostic
256            .span_suggestion_with_applicability(sp, msg, suggestion, applicability);
257        self
258    }
259
260    pub fn span_suggestions_with_applicability(
261        &mut self,
262        sp: Span,
263        msg: &str,
264        suggestions: impl Iterator<Item = String>,
265        applicability: Applicability,
266    ) -> &mut Self {
267        if !self.allow_suggestions {
268            return self;
269        }
270        self.diagnostic
271            .span_suggestions_with_applicability(sp, msg, suggestions, applicability);
272        self
273    }
274
275    pub fn span_suggestion_short_with_applicability(
276        &mut self,
277        sp: Span,
278        msg: &str,
279        suggestion: String,
280        applicability: Applicability,
281    ) -> &mut Self {
282        if !self.allow_suggestions {
283            return self;
284        }
285        self.diagnostic.span_suggestion_short_with_applicability(
286            sp,
287            msg,
288            suggestion,
289            applicability,
290        );
291        self
292    }
293
294    pub fn allow_suggestions(&mut self, allow: bool) -> &mut Self {
295        self.allow_suggestions = allow;
296        self
297    }
298
299    /// Convenience function for internal use, clients should use one of the
300    /// struct_* methods on Handler.
301    pub fn new(handler: &'a Handler, level: Level, message: &str) -> DiagnosticBuilder<'a> {
302        DiagnosticBuilder::new_with_code(handler, level, None, message)
303    }
304
305    /// Convenience function for internal use, clients should use one of the
306    /// struct_* methods on Handler.
307    pub fn new_with_code(
308        handler: &'a Handler,
309        level: Level,
310        code: Option<DiagnosticId>,
311        message: &str,
312    ) -> DiagnosticBuilder<'a> {
313        let diagnostic = Diagnostic::new_with_code(level, code, message);
314        DiagnosticBuilder::new_diagnostic(handler, diagnostic)
315    }
316
317    /// Creates a new `DiagnosticBuilder` with an already constructed
318    /// diagnostic.
319    #[inline(always)] // box
320    pub fn new_diagnostic(handler: &'a Handler, diagnostic: Diagnostic) -> DiagnosticBuilder<'a> {
321        DiagnosticBuilder {
322            handler,
323            diagnostic: Box::new(diagnostic),
324            allow_suggestions: true,
325        }
326    }
327
328    pub fn take(&mut self) -> Diagnostic {
329        std::mem::take(&mut *self.diagnostic)
330    }
331}
332
333impl Debug for DiagnosticBuilder<'_> {
334    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
335        self.diagnostic.fmt(f)
336    }
337}
338
339/// Destructor bomb - a `DiagnosticBuilder` must be either emitted or canceled
340/// or we emit a bug.
341impl Drop for DiagnosticBuilder<'_> {
342    fn drop(&mut self) {
343        if !panicking() && !self.cancelled() {
344            let mut db = DiagnosticBuilder::new(
345                self.handler,
346                Level::Bug,
347                "Error constructed but not emitted",
348            );
349            db.emit();
350            panic!();
351        }
352    }
353}
swc_common/errors/diagnostic_builder.rs

swc_common/errors/
diagnostic_builder.rs
