Rollup merge of #66427 - Mark-Simulacrum:errors-json, r=Centril

Move the JSON error emitter to librustc_errors

This is done both as a cleanup (it makes little sense for this emitter to be in libsyntax), but also as part of broader work to decouple Session from librustc itself.

Along the way, this also moves SourceMap to syntax_pos, which is also nice for the above reasons, as well as allowing dropping the SourceMapper trait from code. This had the unfortunate side-effect of moving `FatalError` to rustc_data_structures (it's needed in syntax_pos, due to SourceMap, but putting it there feels somehow worse).

16 files changed, 99 insertions, 134 deletions

diff --git a/Cargo.lock b/Cargo.lock
index bb2bd3c314c..d3bc70c666f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4439,6 +4439,7 @@ version = "0.0.0"
 dependencies = [
  "arena",
  "cfg-if",
+ "log",
  "rustc_data_structures",
  "rustc_index",
  "rustc_macros",
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index a69584cb90a..4fbc8da9cbf 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -22,7 +22,7 @@ use errors::emitter::HumanReadableErrorType;
 use errors::annotate_snippet_emitter_writer::{AnnotateSnippetEmitterWriter};
 use syntax::edition::Edition;
 use syntax::feature_gate::{self, AttributeType};
-use syntax::json::JsonEmitter;
+use errors::json::JsonEmitter;
 use syntax::source_map;
 use syntax::sess::{ParseSess, ProcessCfgMod};
 use syntax::symbol::Symbol;
diff --git a/src/librustc_codegen_ssa/back/write.rs b/src/librustc_codegen_ssa/back/write.rs
index ed901fa064a..f35a31d59fe 100644
--- a/src/librustc_codegen_ssa/back/write.rs
+++ b/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
     }
 }
diff --git a/src/librustc_errors/annotate_snippet_emitter_writer.rs b/src/librustc_errors/annotate_snippet_emitter_writer.rs
index 491bc2aa6a2..4c5d0178b2c 100644
--- a/src/librustc_errors/annotate_snippet_emitter_writer.rs
+++ b/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 {
diff --git a/src/librustc_errors/emitter.rs b/src/librustc_errors/emitter.rs
index 291920f17f6..ea779982ba9 100644
--- a/src/librustc_errors/emitter.rs
+++ b/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'];
diff --git a/src/libsyntax/json.rs b/src/librustc_errors/json.rs
index 0b157938375..ebbd49bd84a 100644
--- a/src/libsyntax/json.rs
+++ b/src/librustc_errors/json.rs
@@ -9,15 +9,15 @@
 
 // FIXME: spec the JSON output properly.
 
-use crate::source_map::{SourceMap, FilePathMapping};
+use syntax_pos::source_map::{SourceMap, FilePathMapping};
 
-use errors::registry::Registry;
-use errors::{SubDiagnostic, CodeSuggestion, SourceMapper, SourceMapperDyn};
-use errors::{DiagnosticId, Applicability};
-use errors::emitter::{Emitter, HumanReadableErrorType};
+use crate::registry::Registry;
+use crate::{SubDiagnostic, CodeSuggestion};
+use crate::{DiagnosticId, Applicability};
+use crate::emitter::{Emitter, HumanReadableErrorType};
 
 use syntax_pos::{MacroBacktrace, Span, SpanLabel, MultiSpan};
-use rustc_data_structures::sync::{self, Lrc};
+use rustc_data_structures::sync::Lrc;
 use std::io::{self, Write};
 use std::path::Path;
 use std::vec;
@@ -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,
@@ -92,7 +92,7 @@ impl JsonEmitter {
 }
 
 impl Emitter for JsonEmitter {
-    fn emit_diagnostic(&mut self, diag: &errors::Diagnostic) {
+    fn emit_diagnostic(&mut self, diag: &crate::Diagnostic) {
         let data = Diagnostic::from_errors_diagnostic(diag, self);
         let result = if self.pretty {
             writeln!(&mut self.dst, "{}", as_pretty_json(&data))
@@ -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)
     }
 
@@ -212,7 +212,7 @@ struct ArtifactNotification<'a> {
 }
 
 impl Diagnostic {
-    fn from_errors_diagnostic(diag: &errors::Diagnostic,
+    fn from_errors_diagnostic(diag: &crate::Diagnostic,
                                je: &JsonEmitter)
                                -> Diagnostic {
         let sugg = diag.suggestions.iter().map(|sugg| {
diff --git a/src/libsyntax/json/tests.rs b/src/librustc_errors/json/tests.rs
index 1edefd5bc4b..4ab5cd21b0b 100644
--- a/src/libsyntax/json/tests.rs
+++ b/src/librustc_errors/json/tests.rs
@@ -1,11 +1,10 @@
 use super::*;
 
 use crate::json::JsonEmitter;
-use crate::source_map::{FilePathMapping, SourceMap};
-use crate::with_default_globals;
+use syntax_pos::source_map::{FilePathMapping, SourceMap};
 
-use errors::emitter::{ColorConfig, HumanReadableErrorType};
-use errors::Handler;
+use crate::emitter::{ColorConfig, HumanReadableErrorType};
+use crate::Handler;
 use rustc_serialize::json::decode;
 use syntax_pos::{BytePos, Span};
 
@@ -40,6 +39,13 @@ impl<T: Write> Write for Shared<T> {
     }
 }
 
+fn with_default_globals(f: impl FnOnce()) {
+    let globals = syntax_pos::Globals::new(syntax_pos::edition::DEFAULT_EDITION);
+    syntax_pos::GLOBALS.set(&globals, || {
+        syntax_pos::GLOBALS.set(&globals, f)
+    })
+}
+
 /// Test the span yields correct positions in JSON.
 fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) {
     let expected_output = TestData { spans: vec![expected_output] };
diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index 8ee28875c62..17765ef9dee 100644
--- a/src/librustc_errors/lib.rs
+++ b/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;
@@ -35,17 +37,7 @@ mod snippet;
 pub mod registry;
 mod styled_buffer;
 mod lock;
-
-use syntax_pos::{
-    BytePos,
-    FileLinesResult,
-    FileName,
-    Loc,
-    MultiSpan,
-    SourceFile,
-    Span,
-    SpanSnippetError,
-};
+pub mod json;
 
 pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
 
@@ -150,26 +142,12 @@ 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};
 
@@ -259,36 +237,7 @@ impl CodeSuggestion {
     }
 }
 
-/// 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;
-
-pub struct FatalErrorMarker;
-
-// Don't implement Send on FatalError. This makes it impossible to panic!(FatalError).
-// We don't want to invoke the panic handler and print a backtrace for fatal errors.
-impl !Send for FatalError {}
-
-impl FatalError {
-    pub fn raise(self) -> ! {
-        panic::resume_unwind(Box::new(FatalErrorMarker))
-    }
-}
-
-impl fmt::Display for FatalError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "parser fatal error")
-    }
-}
-
-impl error::Error for FatalError {
-    fn description(&self) -> &str {
-        "The parser has encountered a fatal error"
-    }
-}
+pub use syntax_pos::fatal_error::{FatalError, FatalErrorMarker};
 
 /// Signifies that the compiler died with an explicit call to `.bug`
 /// or `.span_bug` rather than a failed assertion, etc.
@@ -405,7 +354,7 @@ 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,
@@ -420,7 +369,7 @@ 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(
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index a40325448b1..507732a9107 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -18,7 +18,7 @@ use syntax::ast::CRATE_NODE_ID;
 use syntax::source_map;
 use syntax::attr;
 use syntax::feature_gate::UnstableFeatures;
-use syntax::json::JsonEmitter;
+use errors::json::JsonEmitter;
 use syntax::symbol::sym;
 use syntax_pos::DUMMY_SP;
 use errors;
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index 6290b2137ea..e3eca75dfe7 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -87,12 +87,10 @@ pub mod util {
     pub mod map_in_place;
 }
 
-pub mod json;
-
 pub mod ast;
 pub mod attr;
 pub mod expand;
-pub mod source_map;
+pub use syntax_pos::source_map;
 pub mod entry;
 pub mod feature_gate;
 pub mod mut_visit;
diff --git a/src/libsyntax_pos/Cargo.toml b/src/libsyntax_pos/Cargo.toml
index 378f7a955a3..2cac76085d2 100644
--- a/src/libsyntax_pos/Cargo.toml
+++ b/src/libsyntax_pos/Cargo.toml
@@ -18,3 +18,4 @@ arena = { path = "../libarena" }
 scoped-tls = "1.0"
 unicode-width = "0.1.4"
 cfg-if = "0.1.2"
+log = "0.4"
diff --git a/src/libsyntax_pos/fatal_error.rs b/src/libsyntax_pos/fatal_error.rs
new file mode 100644
index 00000000000..cf7c677d59d
--- /dev/null
+++ b/src/libsyntax_pos/fatal_error.rs
@@ -0,0 +1,30 @@
+/// 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;
+
+pub struct FatalErrorMarker;
+
+// Don't implement Send on FatalError. This makes it impossible to panic!(FatalError).
+// We don't want to invoke the panic handler and print a backtrace for fatal errors.
+impl !Send for FatalError {}
+
+impl FatalError {
+    pub fn raise(self) -> ! {
+        std::panic::resume_unwind(Box::new(FatalErrorMarker))
+    }
+}
+
+impl std::fmt::Display for FatalError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "parser fatal error")
+    }
+}
+
+impl std::error::Error for FatalError {
+    fn description(&self) -> &str {
+        "The parser has encountered a fatal error"
+    }
+}
diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs
index a762d8af49a..b88d6dbc3f3 100644
--- a/src/libsyntax_pos/lib.rs
+++ b/src/libsyntax_pos/lib.rs
@@ -16,6 +16,8 @@
 
 use rustc_serialize::{Encodable, Decodable, Encoder, Decoder};
 
+pub mod source_map;
+
 pub mod edition;
 use edition::Edition;
 pub mod hygiene;
@@ -29,6 +31,7 @@ pub mod symbol;
 pub use symbol::{Symbol, sym};
 
 mod analyze_source_file;
+pub mod fatal_error;
 
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::{Lrc, Lock};
diff --git a/src/libsyntax/source_map.rs b/src/libsyntax_pos/source_map.rs
index d9f618602a4..77d9807225e 100644
--- a/src/libsyntax/source_map.rs
+++ b/src/libsyntax_pos/source_map.rs
@@ -7,8 +7,8 @@
 //! within the `SourceMap`, which upon request can be converted to line and column
 //! information, source code snippets, etc.
 
-pub use syntax_pos::*;
-pub use syntax_pos::hygiene::{ExpnKind, ExpnData};
+pub use crate::*;
+pub use crate::hygiene::{ExpnKind, ExpnData};
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::StableHasher;
@@ -22,8 +22,6 @@ use std::fs;
 use std::io;
 use log::debug;
 
-use errors::SourceMapper;
-
 #[cfg(test)]
 mod tests;
 
@@ -216,7 +214,7 @@ impl SourceMap {
         self.try_new_source_file(filename, src)
             .unwrap_or_else(|OffsetOverflowError| {
                 eprintln!("fatal error: rustc does not support files larger than 4GB");
-                errors::FatalError.raise()
+                crate::fatal_error::FatalError.raise()
             })
     }
 
@@ -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)]
diff --git a/src/libsyntax/source_map/tests.rs b/src/libsyntax_pos/source_map/tests.rs
index 15254336bbf..15254336bbf 100644
--- a/src/libsyntax/source_map/tests.rs
+++ b/src/libsyntax_pos/source_map/tests.rs
diff --git a/src/tools/compiletest/src/json.rs b/src/tools/compiletest/src/json.rs
index 02b09e21ff0..7930d1249e7 100644
--- a/src/tools/compiletest/src/json.rs
+++ b/src/tools/compiletest/src/json.rs
@@ -1,4 +1,4 @@
-//! These structs are a subset of the ones found in `syntax::json`.
+//! These structs are a subset of the ones found in `rustc_errors::json`.
 //! They are only used for deserialization of JSON output provided by libtest.
 
 use crate::errors::{Error, ErrorKind};