1 files changed, 507 insertions, 0 deletions
diff --git a/src/tools/rustfmt/src/parse/session.rs b/src/tools/rustfmt/src/parse/session.rs
new file mode 100644
index 000000000..23db54219
--- /dev/null
+++ b/src/tools/rustfmt/src/parse/session.rs
@@ -0,0 +1,507 @@
+use std::path::Path;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use rustc_data_structures::sync::{Lrc, Send};
+use rustc_errors::emitter::{Emitter, EmitterWriter};
+use rustc_errors::{ColorConfig, Diagnostic, Handler, Level as DiagnosticLevel};
+use rustc_session::parse::ParseSess as RawParseSess;
+use rustc_span::{
+    source_map::{FilePathMapping, SourceMap},
+    symbol, BytePos, Span,
+};
+
+use crate::config::file_lines::LineRange;
+use crate::ignore_path::IgnorePathSet;
+use crate::parse::parser::{ModError, ModulePathSuccess};
+use crate::source_map::LineRangeUtils;
+use crate::utils::starts_with_newline;
+use crate::visitor::SnippetProvider;
+use crate::{Config, ErrorKind, FileName};
+
+/// ParseSess holds structs necessary for constructing a parser.
+pub(crate) struct ParseSess {
+    parse_sess: RawParseSess,
+    ignore_path_set: Lrc<IgnorePathSet>,
+    can_reset_errors: Lrc<AtomicBool>,
+}
+
+/// Emitter which discards every error.
+struct SilentEmitter;
+
+impl Emitter for SilentEmitter {
+    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+        None
+    }
+    fn emit_diagnostic(&mut self, _db: &Diagnostic) {}
+    fn fluent_bundle(&self) -> Option<&Lrc<rustc_errors::FluentBundle>> {
+        None
+    }
+    fn fallback_fluent_bundle(&self) -> &rustc_errors::FluentBundle {
+        panic!("silent emitter attempted to translate a diagnostic");
+    }
+}
+
+fn silent_emitter() -> Box<dyn Emitter + Send> {
+    Box::new(SilentEmitter {})
+}
+
+/// Emit errors against every files expect ones specified in the `ignore_path_set`.
+struct SilentOnIgnoredFilesEmitter {
+    ignore_path_set: Lrc<IgnorePathSet>,
+    source_map: Lrc<SourceMap>,
+    emitter: Box<dyn Emitter + Send>,
+    has_non_ignorable_parser_errors: bool,
+    can_reset: Lrc<AtomicBool>,
+}
+
+impl SilentOnIgnoredFilesEmitter {
+    fn handle_non_ignoreable_error(&mut self, db: &Diagnostic) {
+        self.has_non_ignorable_parser_errors = true;
+        self.can_reset.store(false, Ordering::Release);
+        self.emitter.emit_diagnostic(db);
+    }
+}
+
+impl Emitter for SilentOnIgnoredFilesEmitter {
+    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+        None
+    }
+    fn emit_diagnostic(&mut self, db: &Diagnostic) {
+        if db.level() == DiagnosticLevel::Fatal {
+            return self.handle_non_ignoreable_error(db);
+        }
+        if let Some(primary_span) = &db.span.primary_span() {
+            let file_name = self.source_map.span_to_filename(*primary_span);
+            if let rustc_span::FileName::Real(rustc_span::RealFileName::LocalPath(ref path)) =
+                file_name
+            {
+                if self
+                    .ignore_path_set
+                    .is_match(&FileName::Real(path.to_path_buf()))
+                {
+                    if !self.has_non_ignorable_parser_errors {
+                        self.can_reset.store(true, Ordering::Release);
+                    }
+                    return;
+                }
+            };
+        }
+        self.handle_non_ignoreable_error(db);
+    }
+
+    fn fluent_bundle(&self) -> Option<&Lrc<rustc_errors::FluentBundle>> {
+        self.emitter.fluent_bundle()
+    }
+
+    fn fallback_fluent_bundle(&self) -> &rustc_errors::FluentBundle {
+        self.emitter.fallback_fluent_bundle()
+    }
+}
+
+fn default_handler(
+    source_map: Lrc<SourceMap>,
+    ignore_path_set: Lrc<IgnorePathSet>,
+    can_reset: Lrc<AtomicBool>,
+    hide_parse_errors: bool,
+) -> Handler {
+    let supports_color = term::stderr().map_or(false, |term| term.supports_color());
+    let color_cfg = if supports_color {
+        ColorConfig::Auto
+    } else {
+        ColorConfig::Never
+    };
+
+    let emitter = if hide_parse_errors {
+        silent_emitter()
+    } else {
+        let fallback_bundle =
+            rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
+        Box::new(EmitterWriter::stderr(
+            color_cfg,
+            Some(source_map.clone()),
+            None,
+            fallback_bundle,
+            false,
+            false,
+            None,
+            false,
+        ))
+    };
+    Handler::with_emitter(
+        true,
+        None,
+        Box::new(SilentOnIgnoredFilesEmitter {
+            has_non_ignorable_parser_errors: false,
+            source_map,
+            emitter,
+            ignore_path_set,
+            can_reset,
+        }),
+    )
+}
+
+impl ParseSess {
+    pub(crate) fn new(config: &Config) -> Result<ParseSess, ErrorKind> {
+        let ignore_path_set = match IgnorePathSet::from_ignore_list(&config.ignore()) {
+            Ok(ignore_path_set) => Lrc::new(ignore_path_set),
+            Err(e) => return Err(ErrorKind::InvalidGlobPattern(e)),
+        };
+        let source_map = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+        let can_reset_errors = Lrc::new(AtomicBool::new(false));
+
+        let handler = default_handler(
+            Lrc::clone(&source_map),
+            Lrc::clone(&ignore_path_set),
+            Lrc::clone(&can_reset_errors),
+            config.hide_parse_errors(),
+        );
+        let parse_sess = RawParseSess::with_span_handler(handler, source_map);
+
+        Ok(ParseSess {
+            parse_sess,
+            ignore_path_set,
+            can_reset_errors,
+        })
+    }
+
+    /// Determine the submodule path for the given module identifier.
+    ///
+    /// * `id` - The name of the module
+    /// * `relative` - If Some(symbol), the symbol name is a directory relative to the dir_path.
+    ///   If relative is Some, resolve the submodle at {dir_path}/{symbol}/{id}.rs
+    ///   or {dir_path}/{symbol}/{id}/mod.rs. if None, resolve the module at {dir_path}/{id}.rs.
+    /// *  `dir_path` - Module resolution will occur relative to this directory.
+    pub(crate) fn default_submod_path(
+        &self,
+        id: symbol::Ident,
+        relative: Option<symbol::Ident>,
+        dir_path: &Path,
+    ) -> Result<ModulePathSuccess, ModError<'_>> {
+        rustc_expand::module::default_submod_path(&self.parse_sess, id, relative, dir_path).or_else(
+            |e| {
+                // If resloving a module relative to {dir_path}/{symbol} fails because a file
+                // could not be found, then try to resolve the module relative to {dir_path}.
+                // If we still can't find the module after searching for it in {dir_path},
+                // surface the original error.
+                if matches!(e, ModError::FileNotFound(..)) && relative.is_some() {
+                    rustc_expand::module::default_submod_path(&self.parse_sess, id, None, dir_path)
+                        .map_err(|_| e)
+                } else {
+                    Err(e)
+                }
+            },
+        )
+    }
+
+    pub(crate) fn is_file_parsed(&self, path: &Path) -> bool {
+        self.parse_sess
+            .source_map()
+            .get_source_file(&rustc_span::FileName::Real(
+                rustc_span::RealFileName::LocalPath(path.to_path_buf()),
+            ))
+            .is_some()
+    }
+
+    pub(crate) fn ignore_file(&self, path: &FileName) -> bool {
+        self.ignore_path_set.as_ref().is_match(path)
+    }
+
+    pub(crate) fn set_silent_emitter(&mut self) {
+        self.parse_sess.span_diagnostic = Handler::with_emitter(true, None, silent_emitter());
+    }
+
+    pub(crate) fn span_to_filename(&self, span: Span) -> FileName {
+        self.parse_sess.source_map().span_to_filename(span).into()
+    }
+
+    pub(crate) fn span_to_file_contents(&self, span: Span) -> Lrc<rustc_span::SourceFile> {
+        self.parse_sess
+            .source_map()
+            .lookup_source_file(span.data().lo)
+    }
+
+    pub(crate) fn span_to_first_line_string(&self, span: Span) -> String {
+        let file_lines = self.parse_sess.source_map().span_to_lines(span).ok();
+
+        match file_lines {
+            Some(fl) => fl
+                .file
+                .get_line(fl.lines[0].line_index)
+                .map_or_else(String::new, |s| s.to_string()),
+            None => String::new(),
+        }
+    }
+
+    pub(crate) fn line_of_byte_pos(&self, pos: BytePos) -> usize {
+        self.parse_sess.source_map().lookup_char_pos(pos).line
+    }
+
+    // TODO(calebcartwright): Preemptive, currently unused addition
+    // that will be used to support formatting scenarios that take original
+    // positions into account
+    /// Determines whether two byte positions are in the same source line.
+    #[allow(dead_code)]
+    pub(crate) fn byte_pos_same_line(&self, a: BytePos, b: BytePos) -> bool {
+        self.line_of_byte_pos(a) == self.line_of_byte_pos(b)
+    }
+
+    pub(crate) fn span_to_debug_info(&self, span: Span) -> String {
+        self.parse_sess.source_map().span_to_diagnostic_string(span)
+    }
+
+    pub(crate) fn inner(&self) -> &RawParseSess {
+        &self.parse_sess
+    }
+
+    pub(crate) fn snippet_provider(&self, span: Span) -> SnippetProvider {
+        let source_file = self.parse_sess.source_map().lookup_char_pos(span.lo()).file;
+        SnippetProvider::new(
+            source_file.start_pos,
+            source_file.end_pos,
+            Lrc::clone(source_file.src.as_ref().unwrap()),
+        )
+    }
+
+    pub(crate) fn get_original_snippet(&self, file_name: &FileName) -> Option<Lrc<String>> {
+        self.parse_sess
+            .source_map()
+            .get_source_file(&file_name.into())
+            .and_then(|source_file| source_file.src.clone())
+    }
+}
+
+// Methods that should be restricted within the parse module.
+impl ParseSess {
+    pub(super) fn emit_diagnostics(&self, diagnostics: Vec<Diagnostic>) {
+        for mut diagnostic in diagnostics {
+            self.parse_sess
+                .span_diagnostic
+                .emit_diagnostic(&mut diagnostic);
+        }
+    }
+
+    pub(super) fn can_reset_errors(&self) -> bool {
+        self.can_reset_errors.load(Ordering::Acquire)
+    }
+
+    pub(super) fn has_errors(&self) -> bool {
+        self.parse_sess.span_diagnostic.has_errors().is_some()
+    }
+
+    pub(super) fn reset_errors(&self) {
+        self.parse_sess.span_diagnostic.reset_err_count();
+    }
+}
+
+impl LineRangeUtils for ParseSess {
+    fn lookup_line_range(&self, span: Span) -> LineRange {
+        let snippet = self
+            .parse_sess
+            .source_map()
+            .span_to_snippet(span)
+            .unwrap_or_default();
+        let lo = self.parse_sess.source_map().lookup_line(span.lo()).unwrap();
+        let hi = self.parse_sess.source_map().lookup_line(span.hi()).unwrap();
+
+        debug_assert_eq!(
+            lo.sf.name, hi.sf.name,
+            "span crossed file boundary: lo: {:?}, hi: {:?}",
+            lo, hi
+        );
+
+        // in case the span starts with a newline, the line range is off by 1 without the
+        // adjustment below
+        let offset = 1 + if starts_with_newline(&snippet) { 1 } else { 0 };
+        // Line numbers start at 1
+        LineRange {
+            file: lo.sf.clone(),
+            lo: lo.line + offset,
+            hi: hi.line + offset,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use rustfmt_config_proc_macro::nightly_only_test;
+
+    mod emitter {
+        use super::*;
+        use crate::config::IgnoreList;
+        use crate::utils::mk_sp;
+        use rustc_errors::MultiSpan;
+        use rustc_span::{FileName as SourceMapFileName, RealFileName};
+        use std::path::PathBuf;
+        use std::sync::atomic::AtomicU32;
+
+        struct TestEmitter {
+            num_emitted_errors: Lrc<AtomicU32>,
+        }
+
+        impl Emitter for TestEmitter {
+            fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+                None
+            }
+            fn emit_diagnostic(&mut self, _db: &Diagnostic) {
+                self.num_emitted_errors.fetch_add(1, Ordering::Release);
+            }
+            fn fluent_bundle(&self) -> Option<&Lrc<rustc_errors::FluentBundle>> {
+                None
+            }
+            fn fallback_fluent_bundle(&self) -> &rustc_errors::FluentBundle {
+                panic!("test emitter attempted to translate a diagnostic");
+            }
+        }
+
+        fn build_diagnostic(level: DiagnosticLevel, span: Option<MultiSpan>) -> Diagnostic {
+            let mut diag = Diagnostic::new(level, "");
+            diag.message.clear();
+            if let Some(span) = span {
+                diag.span = span;
+            }
+            diag
+        }
+
+        fn build_emitter(
+            num_emitted_errors: Lrc<AtomicU32>,
+            can_reset: Lrc<AtomicBool>,
+            source_map: Option<Lrc<SourceMap>>,
+            ignore_list: Option<IgnoreList>,
+        ) -> SilentOnIgnoredFilesEmitter {
+            let emitter_writer = TestEmitter { num_emitted_errors };
+            let source_map =
+                source_map.unwrap_or_else(|| Lrc::new(SourceMap::new(FilePathMapping::empty())));
+            let ignore_path_set = Lrc::new(
+                IgnorePathSet::from_ignore_list(&ignore_list.unwrap_or_default()).unwrap(),
+            );
+            SilentOnIgnoredFilesEmitter {
+                has_non_ignorable_parser_errors: false,
+                source_map,
+                emitter: Box::new(emitter_writer),
+                ignore_path_set,
+                can_reset,
+            }
+        }
+
+        fn get_ignore_list(config: &str) -> IgnoreList {
+            Config::from_toml(config, Path::new("")).unwrap().ignore()
+        }
+
+        #[test]
+        fn handles_fatal_parse_error_in_ignored_file() {
+            let num_emitted_errors = Lrc::new(AtomicU32::new(0));
+            let can_reset_errors = Lrc::new(AtomicBool::new(false));
+            let ignore_list = get_ignore_list(r#"ignore = ["foo.rs"]"#);
+            let source_map = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+            let source =
+                String::from(r#"extern "system" fn jni_symbol!( funcName ) ( ... ) -> {} "#);
+            source_map.new_source_file(
+                SourceMapFileName::Real(RealFileName::LocalPath(PathBuf::from("foo.rs"))),
+                source,
+            );
+            let mut emitter = build_emitter(
+                Lrc::clone(&num_emitted_errors),
+                Lrc::clone(&can_reset_errors),
+                Some(Lrc::clone(&source_map)),
+                Some(ignore_list),
+            );
+            let span = MultiSpan::from_span(mk_sp(BytePos(0), BytePos(1)));
+            let fatal_diagnostic = build_diagnostic(DiagnosticLevel::Fatal, Some(span));
+            emitter.emit_diagnostic(&fatal_diagnostic);
+            assert_eq!(num_emitted_errors.load(Ordering::Acquire), 1);
+            assert_eq!(can_reset_errors.load(Ordering::Acquire), false);
+        }
+
+        #[nightly_only_test]
+        #[test]
+        fn handles_recoverable_parse_error_in_ignored_file() {
+            let num_emitted_errors = Lrc::new(AtomicU32::new(0));
+            let can_reset_errors = Lrc::new(AtomicBool::new(false));
+            let ignore_list = get_ignore_list(r#"ignore = ["foo.rs"]"#);
+            let source_map = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+            let source = String::from(r#"pub fn bar() { 1x; }"#);
+            source_map.new_source_file(
+                SourceMapFileName::Real(RealFileName::LocalPath(PathBuf::from("foo.rs"))),
+                source,
+            );
+            let mut emitter = build_emitter(
+                Lrc::clone(&num_emitted_errors),
+                Lrc::clone(&can_reset_errors),
+                Some(Lrc::clone(&source_map)),
+                Some(ignore_list),
+            );
+            let span = MultiSpan::from_span(mk_sp(BytePos(0), BytePos(1)));
+            let non_fatal_diagnostic = build_diagnostic(DiagnosticLevel::Warning(None), Some(span));
+            emitter.emit_diagnostic(&non_fatal_diagnostic);
+            assert_eq!(num_emitted_errors.load(Ordering::Acquire), 0);
+            assert_eq!(can_reset_errors.load(Ordering::Acquire), true);
+        }
+
+        #[nightly_only_test]
+        #[test]
+        fn handles_recoverable_parse_error_in_non_ignored_file() {
+            let num_emitted_errors = Lrc::new(AtomicU32::new(0));
+            let can_reset_errors = Lrc::new(AtomicBool::new(false));
+            let source_map = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+            let source = String::from(r#"pub fn bar() { 1x; }"#);
+            source_map.new_source_file(
+                SourceMapFileName::Real(RealFileName::LocalPath(PathBuf::from("foo.rs"))),
+                source,
+            );
+            let mut emitter = build_emitter(
+                Lrc::clone(&num_emitted_errors),
+                Lrc::clone(&can_reset_errors),
+                Some(Lrc::clone(&source_map)),
+                None,
+            );
+            let span = MultiSpan::from_span(mk_sp(BytePos(0), BytePos(1)));
+            let non_fatal_diagnostic = build_diagnostic(DiagnosticLevel::Warning(None), Some(span));
+            emitter.emit_diagnostic(&non_fatal_diagnostic);
+            assert_eq!(num_emitted_errors.load(Ordering::Acquire), 1);
+            assert_eq!(can_reset_errors.load(Ordering::Acquire), false);
+        }
+
+        #[nightly_only_test]
+        #[test]
+        fn handles_mix_of_recoverable_parse_error() {
+            let num_emitted_errors = Lrc::new(AtomicU32::new(0));
+            let can_reset_errors = Lrc::new(AtomicBool::new(false));
+            let source_map = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+            let ignore_list = get_ignore_list(r#"ignore = ["foo.rs"]"#);
+            let bar_source = String::from(r#"pub fn bar() { 1x; }"#);
+            let foo_source = String::from(r#"pub fn foo() { 1x; }"#);
+            let fatal_source =
+                String::from(r#"extern "system" fn jni_symbol!( funcName ) ( ... ) -> {} "#);
+            source_map.new_source_file(
+                SourceMapFileName::Real(RealFileName::LocalPath(PathBuf::from("bar.rs"))),
+                bar_source,
+            );
+            source_map.new_source_file(
+                SourceMapFileName::Real(RealFileName::LocalPath(PathBuf::from("foo.rs"))),
+                foo_source,
+            );
+            source_map.new_source_file(
+                SourceMapFileName::Real(RealFileName::LocalPath(PathBuf::from("fatal.rs"))),
+                fatal_source,
+            );
+            let mut emitter = build_emitter(
+                Lrc::clone(&num_emitted_errors),
+                Lrc::clone(&can_reset_errors),
+                Some(Lrc::clone(&source_map)),
+                Some(ignore_list),
+            );
+            let bar_span = MultiSpan::from_span(mk_sp(BytePos(0), BytePos(1)));
+            let foo_span = MultiSpan::from_span(mk_sp(BytePos(21), BytePos(22)));
+            let bar_diagnostic = build_diagnostic(DiagnosticLevel::Warning(None), Some(bar_span));
+            let foo_diagnostic = build_diagnostic(DiagnosticLevel::Warning(None), Some(foo_span));
+            let fatal_diagnostic = build_diagnostic(DiagnosticLevel::Fatal, None);
+            emitter.emit_diagnostic(&bar_diagnostic);
+            emitter.emit_diagnostic(&foo_diagnostic);
+            emitter.emit_diagnostic(&fatal_diagnostic);
+            assert_eq!(num_emitted_errors.load(Ordering::Acquire), 2);
+            assert_eq!(can_reset_errors.load(Ordering::Acquire), false);
+        }
+    }
+}