Remove SourceMapper trait

SourceMap is now in the root of all rustc-specific crates, syntax_pos,
so there's no need for the trait object to decouple the dependencies
between librustc_errors and libsyntax as was needed previously.

Author: Mark-Simulacrum

src/librustc_codegen_ssa/back/write.rs

@@ -23,7 +23,8 @@ use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_fs_util::link_or_copy;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::Lrc;
-use rustc_errors::{Handler, Level, FatalError, DiagnosticId, SourceMapperDyn};
+use rustc_errors::{Handler, Level, FatalError, DiagnosticId};
+use syntax_pos::source_map::SourceMap;
 use rustc_errors::emitter::{Emitter};
 use rustc_target::spec::MergeFunctions;
 use syntax::attr;
@@ -1679,7 +1680,7 @@ impl Emitter for SharedEmitter {
         }
         drop(self.sender.send(SharedEmitterMessage::AbortIfErrors));
     }
-    fn source_map(&self) -> Option<&Lrc<SourceMapperDyn>> {
+    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
         None
     }
 }

src/librustc_errors/annotate_snippet_emitter_writer.rs

@@ -6,9 +6,10 @@
 //! [annotate_snippets]: https://docs.rs/crate/annotate-snippets/
 
 use syntax_pos::{SourceFile, MultiSpan, Loc};
+use syntax_pos::source_map::SourceMap;
 use crate::{
     Level, CodeSuggestion, Diagnostic, Emitter,
-    SourceMapperDyn, SubDiagnostic, DiagnosticId
+    SubDiagnostic, DiagnosticId
 };
 use crate::emitter::FileWithAnnotatedLines;
 use rustc_data_structures::sync::Lrc;
@@ -20,7 +21,7 @@ use annotate_snippets::formatter::DisplayListFormatter;
 
 /// Generates diagnostics using annotate-snippet
 pub struct AnnotateSnippetEmitterWriter {
-    source_map: Option<Lrc<SourceMapperDyn>>,
+    source_map: Option<Lrc<SourceMap>>,
     /// If true, hides the longer explanation text
     short_message: bool,
     /// If true, will normalize line numbers with `LL` to prevent noise in UI test diffs.
@@ -49,7 +50,7 @@ impl Emitter for AnnotateSnippetEmitterWriter {
                                    &suggestions);
     }
 
-    fn source_map(&self) -> Option<&Lrc<SourceMapperDyn>> {
+    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
         self.source_map.as_ref()
     }
 
@@ -61,7 +62,7 @@ impl Emitter for AnnotateSnippetEmitterWriter {
 /// Collects all the data needed to generate the data structures needed for the
 /// `annotate-snippets` library.
 struct DiagnosticConverter<'a> {
-    source_map: Option<Lrc<SourceMapperDyn>>,
+    source_map: Option<Lrc<SourceMap>>,
     level: Level,
     message: String,
     code: Option<DiagnosticId>,
@@ -168,7 +169,7 @@ impl<'a>  DiagnosticConverter<'a> {
 
 impl AnnotateSnippetEmitterWriter {
     pub fn new(
-        source_map: Option<Lrc<SourceMapperDyn>>,
+        source_map: Option<Lrc<SourceMap>>,
         short_message: bool,
         external_macro_backtrace: bool,
     ) -> Self {

src/librustc_errors/emitter.rs

@@ -10,10 +10,11 @@
 use Destination::*;
 
 use syntax_pos::{SourceFile, Span, MultiSpan};
+use syntax_pos::source_map::SourceMap;
 
 use crate::{
     Level, CodeSuggestion, Diagnostic, SubDiagnostic, pluralize,
-    SuggestionStyle, SourceMapper, SourceMapperDyn, DiagnosticId,
+    SuggestionStyle, DiagnosticId,
 };
 use crate::Level::Error;
 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, StyledString, Style};
@@ -49,7 +50,7 @@ impl HumanReadableErrorType {
     pub fn new_emitter(
         self,
         dst: Box<dyn Write + Send>,
-        source_map: Option<Lrc<SourceMapperDyn>>,
+        source_map: Option<Lrc<SourceMap>>,
         teach: bool,
         terminal_width: Option<usize>,
         external_macro_backtrace: bool,
@@ -192,7 +193,7 @@ pub trait Emitter {
         true
     }
 
-    fn source_map(&self) -> Option<&Lrc<SourceMapperDyn>>;
+    fn source_map(&self) -> Option<&Lrc<SourceMap>>;
 
     /// Formats the substitutions of the primary_span
     ///
@@ -271,7 +272,7 @@ pub trait Emitter {
     // point directly at <*macros>. Since these are often difficult to read, this
     // will change the span to point at the use site.
     fn fix_multispans_in_std_macros(&self,
-                                    source_map: &Option<Lrc<SourceMapperDyn>>,
+                                    source_map: &Option<Lrc<SourceMap>>,
                                     span: &mut MultiSpan,
                                     children: &mut Vec<SubDiagnostic>,
                                     level: &Level,
@@ -311,7 +312,7 @@ pub trait Emitter {
     // <*macros>. Since these locations are often difficult to read, we move these Spans from
     // <*macros> to their corresponding use site.
     fn fix_multispan_in_std_macros(&self,
-                                   source_map: &Option<Lrc<SourceMapperDyn>>,
+                                   source_map: &Option<Lrc<SourceMap>>,
                                    span: &mut MultiSpan,
                                    always_backtrace: bool) -> bool {
         let sm = match source_map {
@@ -397,7 +398,7 @@ pub trait Emitter {
 }
 
 impl Emitter for EmitterWriter {
-    fn source_map(&self) -> Option<&Lrc<SourceMapperDyn>> {
+    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
         self.sm.as_ref()
     }
 
@@ -428,7 +429,7 @@ impl Emitter for EmitterWriter {
 pub struct SilentEmitter;
 
 impl Emitter for SilentEmitter {
-    fn source_map(&self) -> Option<&Lrc<SourceMapperDyn>> { None }
+    fn source_map(&self) -> Option<&Lrc<SourceMap>> { None }
     fn emit_diagnostic(&mut self, _: &Diagnostic) {}
 }
 
@@ -476,7 +477,7 @@ impl ColorConfig {
 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
 pub struct EmitterWriter {
     dst: Destination,
-    sm: Option<Lrc<SourceMapperDyn>>,
+    sm: Option<Lrc<SourceMap>>,
     short_message: bool,
     teach: bool,
     ui_testing: bool,
@@ -495,7 +496,7 @@ pub struct FileWithAnnotatedLines {
 impl EmitterWriter {
     pub fn stderr(
         color_config: ColorConfig,
-        source_map: Option<Lrc<SourceMapperDyn>>,
+        source_map: Option<Lrc<SourceMap>>,
         short_message: bool,
         teach: bool,
         terminal_width: Option<usize>,
@@ -515,7 +516,7 @@ impl EmitterWriter {
 
     pub fn new(
         dst: Box<dyn Write + Send>,
-        source_map: Option<Lrc<SourceMapperDyn>>,
+        source_map: Option<Lrc<SourceMap>>,
         short_message: bool,
         teach: bool,
         colored: bool,
@@ -1685,7 +1686,7 @@ impl FileWithAnnotatedLines {
     /// This helps us quickly iterate over the whole message (including secondary file spans)
     pub fn collect_annotations(
         msp: &MultiSpan,
-        source_map: &Option<Lrc<SourceMapperDyn>>
+        source_map: &Option<Lrc<SourceMap>>
     ) -> Vec<FileWithAnnotatedLines> {
         fn add_annotation_to_file(file_vec: &mut Vec<FileWithAnnotatedLines>,
                                   file: Lrc<SourceFile>,
@@ -2067,7 +2068,7 @@ impl<'a> Drop for WritableDst<'a> {
 }
 
 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
-pub fn is_case_difference(sm: &dyn SourceMapper, suggested: &str, sp: Span) -> bool {
+pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
     // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
     let found = sm.span_to_snippet(sp).unwrap();
     let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];

src/librustc_errors/lib.rs

@@ -18,6 +18,8 @@ use registry::Registry;
 use rustc_data_structures::sync::{self, Lrc, Lock};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_data_structures::stable_hasher::StableHasher;
+use syntax_pos::source_map::SourceMap;
+use syntax_pos::{Loc, Span, MultiSpan};
 
 use std::borrow::Cow;
 use std::cell::Cell;
@@ -36,17 +38,6 @@ pub mod registry;
 mod styled_buffer;
 mod lock;
 
-use syntax_pos::{
-    BytePos,
-    FileLinesResult,
-    FileName,
-    Loc,
-    MultiSpan,
-    SourceFile,
-    Span,
-    SpanSnippetError,
-};
-
 pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
 
 // `PResult` is used a lot. Make sure it doesn't unintentionally get bigger.
@@ -150,26 +141,12 @@ pub struct SubstitutionPart {
     pub snippet: String,
 }
 
-pub type SourceMapperDyn = dyn SourceMapper + sync::Send + sync::Sync;
-
-pub trait SourceMapper {
-    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_snippet(&self, sp: Span) -> Result<String, SpanSnippetError>;
-    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_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool;
-    fn doctest_offset_line(&self, file: &FileName, line: usize) -> usize;
-}
-
 impl CodeSuggestion {
     /// Returns the assembled code suggestions, whether they should be shown with an underline
     /// and whether the substitution only differs in capitalization.
     pub fn splice_lines(
         &self,
-        cm: &SourceMapperDyn,
+        cm: &SourceMap,
     ) -> Vec<(String, Vec<SubstitutionPart>, bool)> {
         use syntax_pos::{CharPos, Pos};
 
@@ -376,7 +353,7 @@ impl Handler {
         color_config: ColorConfig,
         can_emit_warnings: bool,
         treat_err_as_bug: Option<usize>,
-        cm: Option<Lrc<SourceMapperDyn>>,
+        cm: Option<Lrc<SourceMap>>,
     ) -> Self {
         Self::with_tty_emitter_and_flags(
             color_config,
@@ -391,7 +368,7 @@ impl Handler {
 
     pub fn with_tty_emitter_and_flags(
         color_config: ColorConfig,
-        cm: Option<Lrc<SourceMapperDyn>>,
+        cm: Option<Lrc<SourceMap>>,
         flags: HandlerFlags,
     ) -> Self {
         let emitter = Box::new(EmitterWriter::stderr(

src/libsyntax/json.rs

@@ -12,7 +12,7 @@
 use crate::source_map::{SourceMap, FilePathMapping};
 
 use errors::registry::Registry;
-use errors::{SubDiagnostic, CodeSuggestion, SourceMapper, SourceMapperDyn};
+use errors::{SubDiagnostic, CodeSuggestion};
 use errors::{DiagnosticId, Applicability};
 use errors::emitter::{Emitter, HumanReadableErrorType};
 
@@ -31,7 +31,7 @@ mod tests;
 pub struct JsonEmitter {
     dst: Box<dyn Write + Send>,
     registry: Option<Registry>,
-    sm: Lrc<dyn SourceMapper + sync::Send + sync::Sync>,
+    sm: Lrc<SourceMap>,
     pretty: bool,
     ui_testing: bool,
     json_rendered: HumanReadableErrorType,
@@ -116,7 +116,7 @@ impl Emitter for JsonEmitter {
         }
     }
 
-    fn source_map(&self) -> Option<&Lrc<SourceMapperDyn>> {
+    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
         Some(&self.sm)
     }
 

src/libsyntax_pos/source_map.rs

@@ -22,8 +22,6 @@ use std::fs;
 use std::io;
 use log::debug;
 
-use errors::SourceMapper;
-
 #[cfg(test)]
 mod tests;
 
@@ -956,28 +954,15 @@ impl SourceMap {
 
         None
     }
-}
-
-impl SourceMapper for SourceMap {
-    fn lookup_char_pos(&self, pos: BytePos) -> Loc {
-        self.lookup_char_pos(pos)
-    }
-    fn span_to_lines(&self, sp: Span) -> FileLinesResult {
-        self.span_to_lines(sp)
-    }
-    fn span_to_string(&self, sp: Span) -> String {
-        self.span_to_string(sp)
-    }
-    fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
-        self.span_to_snippet(sp)
-    }
-    fn span_to_filename(&self, sp: Span) -> FileName {
-        self.span_to_filename(sp)
-    }
-    fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
-        self.merge_spans(sp_lhs, sp_rhs)
+    pub fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool {
+        source_file.add_external_src(
+            || match source_file.name {
+                FileName::Real(ref name) => self.file_loader.read_file(name).ok(),
+                _ => None,
+            }
+        )
     }
-    fn call_span_if_macro(&self, sp: Span) -> Span {
+    pub fn call_span_if_macro(&self, sp: Span) -> Span {
         if self.span_to_filename(sp.clone()).is_macros() {
             let v = sp.macro_backtrace();
             if let Some(use_site) = v.last() {
@@ -986,17 +971,6 @@ impl SourceMapper for SourceMap {
         }
         sp
     }
-    fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool {
-        source_file.add_external_src(
-            || match source_file.name {
-                FileName::Real(ref name) => self.file_loader.read_file(name).ok(),
-                _ => None,
-            }
-        )
-    }
-    fn doctest_offset_line(&self, file: &FileName, line: usize) -> usize {
-        self.doctest_offset_line(file, line)
-    }
 }
 
 #[derive(Clone)]