syntax: extract sess.rs for ParseSess

src/libsyntax/parse/mod.rs

@@ -1,26 +1,19 @@
 //! The main parser interface.
 
-use crate::ast::{self, CrateConfig, NodeId};
-use crate::early_buffered_lints::{BufferedEarlyLint, BufferedEarlyLintId};
-use crate::source_map::{SourceMap, FilePathMapping};
-use crate::feature_gate::UnstableFeatures;
+use crate::ast;
 use crate::parse::parser::{Parser, emit_unclosed_delims};
 use crate::parse::token::{Nonterminal, TokenKind};
 use crate::tokenstream::{self, TokenStream, TokenTree};
 use crate::print::pprust;
-use crate::symbol::Symbol;
 
-use errors::{Applicability, FatalError, Level, Handler, ColorConfig, Diagnostic, DiagnosticBuilder};
-use rustc_data_structures::fx::{FxHashSet, FxHashMap};
+use errors::{FatalError, Level, Diagnostic, DiagnosticBuilder};
 #[cfg(target_arch = "x86_64")]
 use rustc_data_structures::static_assert_size;
-use rustc_data_structures::sync::{Lrc, Lock, Once};
-use syntax_pos::{Span, SourceFile, FileName, MultiSpan};
-use syntax_pos::edition::Edition;
-use syntax_pos::hygiene::ExpnId;
+use rustc_data_structures::sync::Lrc;
+use syntax_pos::{Span, SourceFile, FileName};
 
 use std::borrow::Cow;
-use std::path::{Path, PathBuf};
+use std::path::Path;
 use std::str;
 
 use log::info;
@@ -33,6 +26,8 @@ pub mod parser;
 pub mod attr;
 pub mod lexer;
 pub mod token;
+mod sess;
+pub use sess::ParseSess;
 
 crate mod classify;
 crate mod diagnostics;
@@ -46,112 +41,6 @@ pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
 #[cfg(target_arch = "x86_64")]
 static_assert_size!(PResult<'_, bool>, 16);
 
-/// Collected spans during parsing for places where a certain feature was
-/// used and should be feature gated accordingly in `check_crate`.
-#[derive(Default)]
-pub struct GatedSpans {
-    /// Spans collected for gating `let_chains`, e.g. `if a && let b = c {}`.
-    pub let_chains: Lock<Vec<Span>>,
-    /// Spans collected for gating `async_closure`, e.g. `async || ..`.
-    pub async_closure: Lock<Vec<Span>>,
-    /// Spans collected for gating `yield e?` expressions (`generators` gate).
-    pub yields: Lock<Vec<Span>>,
-    /// Spans collected for gating `or_patterns`, e.g. `Some(Foo | Bar)`.
-    pub or_patterns: Lock<Vec<Span>>,
-    /// Spans collected for gating `const_extern_fn`, e.g. `const extern fn foo`.
-    pub const_extern_fn: Lock<Vec<Span>>,
-}
-
-/// Info about a parsing session.
-pub struct ParseSess {
-    pub span_diagnostic: Handler,
-    pub unstable_features: UnstableFeatures,
-    pub config: CrateConfig,
-    pub edition: Edition,
-    pub missing_fragment_specifiers: Lock<FxHashSet<Span>>,
-    /// Places where raw identifiers were used. This is used for feature-gating raw identifiers.
-    pub raw_identifier_spans: Lock<Vec<Span>>,
-    /// Used to determine and report recursive module inclusions.
-    included_mod_stack: Lock<Vec<PathBuf>>,
-    source_map: Lrc<SourceMap>,
-    pub buffered_lints: Lock<Vec<BufferedEarlyLint>>,
-    /// Contains the spans of block expressions that could have been incomplete based on the
-    /// operation token that followed it, but that the parser cannot identify without further
-    /// analysis.
-    pub ambiguous_block_expr_parse: Lock<FxHashMap<Span, Span>>,
-    pub injected_crate_name: Once<Symbol>,
-    pub gated_spans: GatedSpans,
-}
-
-impl ParseSess {
-    pub fn new(file_path_mapping: FilePathMapping) -> Self {
-        let cm = Lrc::new(SourceMap::new(file_path_mapping));
-        let handler = Handler::with_tty_emitter(
-            ColorConfig::Auto,
-            true,
-            None,
-            Some(cm.clone()),
-        );
-        ParseSess::with_span_handler(handler, cm)
-    }
-
-    pub fn with_span_handler(handler: Handler, source_map: Lrc<SourceMap>) -> Self {
-        Self {
-            span_diagnostic: handler,
-            unstable_features: UnstableFeatures::from_environment(),
-            config: FxHashSet::default(),
-            edition: ExpnId::root().expn_data().edition,
-            missing_fragment_specifiers: Lock::new(FxHashSet::default()),
-            raw_identifier_spans: Lock::new(Vec::new()),
-            included_mod_stack: Lock::new(vec![]),
-            source_map,
-            buffered_lints: Lock::new(vec![]),
-            ambiguous_block_expr_parse: Lock::new(FxHashMap::default()),
-            injected_crate_name: Once::new(),
-            gated_spans: GatedSpans::default(),
-        }
-    }
-
-    #[inline]
-    pub fn source_map(&self) -> &SourceMap {
-        &self.source_map
-    }
-
-    pub fn buffer_lint<S: Into<MultiSpan>>(&self,
-        lint_id: BufferedEarlyLintId,
-        span: S,
-        id: NodeId,
-        msg: &str,
-    ) {
-        self.buffered_lints.with_lock(|buffered_lints| {
-            buffered_lints.push(BufferedEarlyLint{
-                span: span.into(),
-                id,
-                msg: msg.into(),
-                lint_id,
-            });
-        });
-    }
-
-    /// Extend an error with a suggestion to wrap an expression with parentheses to allow the
-    /// parser to continue parsing the following operation as part of the same expression.
-    pub fn expr_parentheses_needed(
-        &self,
-        err: &mut DiagnosticBuilder<'_>,
-        span: Span,
-        alt_snippet: Option<String>,
-    ) {
-        if let Some(snippet) = self.source_map().span_to_snippet(span).ok().or(alt_snippet) {
-            err.span_suggestion(
-                span,
-                "parentheses are required to parse this as an expression",
-                format!("({})", snippet),
-                Applicability::MachineApplicable,
-            );
-        }
-    }
-}
-
 #[derive(Clone)]
 pub struct Directory<'a> {
     pub path: Cow<'a, Path>,

src/libsyntax/parse/parser.rs

@@ -1366,7 +1366,7 @@ impl<'a> Parser<'a> {
             ],
             Applicability::MaybeIncorrect,
         ).span_suggestion(
-            self.sess.source_map.next_point(self.prev_span),
+            self.sess.source_map().next_point(self.prev_span),
             "add a semicolon",
             ';'.to_string(),
             Applicability::MaybeIncorrect,

src/libsyntax/parse/sess.rs

@@ -0,0 +1,124 @@
+//! Contains `ParseSess` which holds state living beyond what one `Parser` might.
+//! It also serves as an input to the parser itself.
+
+use crate::ast::{CrateConfig, NodeId};
+use crate::early_buffered_lints::{BufferedEarlyLint, BufferedEarlyLintId};
+use crate::source_map::{SourceMap, FilePathMapping};
+use crate::feature_gate::UnstableFeatures;
+
+use errors::{Applicability, Handler, ColorConfig, DiagnosticBuilder};
+use rustc_data_structures::fx::{FxHashSet, FxHashMap};
+use rustc_data_structures::sync::{Lrc, Lock, Once};
+use syntax_pos::{Symbol, Span, MultiSpan};
+use syntax_pos::edition::Edition;
+use syntax_pos::hygiene::ExpnId;
+
+use std::path::PathBuf;
+use std::str;
+
+/// Collected spans during parsing for places where a certain feature was
+/// used and should be feature gated accordingly in `check_crate`.
+#[derive(Default)]
+crate struct GatedSpans {
+    /// Spans collected for gating `let_chains`, e.g. `if a && let b = c {}`.
+    crate let_chains: Lock<Vec<Span>>,
+    /// Spans collected for gating `async_closure`, e.g. `async || ..`.
+    crate async_closure: Lock<Vec<Span>>,
+    /// Spans collected for gating `yield e?` expressions (`generators` gate).
+    crate yields: Lock<Vec<Span>>,
+    /// Spans collected for gating `or_patterns`, e.g. `Some(Foo | Bar)`.
+    crate or_patterns: Lock<Vec<Span>>,
+    /// Spans collected for gating `const_extern_fn`, e.g. `const extern fn foo`.
+    crate const_extern_fn: Lock<Vec<Span>>,
+}
+
+/// Info about a parsing session.
+pub struct ParseSess {
+    pub span_diagnostic: Handler,
+    crate unstable_features: UnstableFeatures,
+    pub config: CrateConfig,
+    pub edition: Edition,
+    pub missing_fragment_specifiers: Lock<FxHashSet<Span>>,
+    /// Places where raw identifiers were used. This is used for feature-gating raw identifiers.
+    pub raw_identifier_spans: Lock<Vec<Span>>,
+    /// Used to determine and report recursive module inclusions.
+    pub(super) included_mod_stack: Lock<Vec<PathBuf>>,
+    source_map: Lrc<SourceMap>,
+    pub buffered_lints: Lock<Vec<BufferedEarlyLint>>,
+    /// Contains the spans of block expressions that could have been incomplete based on the
+    /// operation token that followed it, but that the parser cannot identify without further
+    /// analysis.
+    pub ambiguous_block_expr_parse: Lock<FxHashMap<Span, Span>>,
+    pub injected_crate_name: Once<Symbol>,
+    crate gated_spans: GatedSpans,
+}
+
+impl ParseSess {
+    pub fn new(file_path_mapping: FilePathMapping) -> Self {
+        let cm = Lrc::new(SourceMap::new(file_path_mapping));
+        let handler = Handler::with_tty_emitter(
+            ColorConfig::Auto,
+            true,
+            None,
+            Some(cm.clone()),
+        );
+        ParseSess::with_span_handler(handler, cm)
+    }
+
+    pub fn with_span_handler(handler: Handler, source_map: Lrc<SourceMap>) -> Self {
+        Self {
+            span_diagnostic: handler,
+            unstable_features: UnstableFeatures::from_environment(),
+            config: FxHashSet::default(),
+            edition: ExpnId::root().expn_data().edition,
+            missing_fragment_specifiers: Lock::new(FxHashSet::default()),
+            raw_identifier_spans: Lock::new(Vec::new()),
+            included_mod_stack: Lock::new(vec![]),
+            source_map,
+            buffered_lints: Lock::new(vec![]),
+            ambiguous_block_expr_parse: Lock::new(FxHashMap::default()),
+            injected_crate_name: Once::new(),
+            gated_spans: GatedSpans::default(),
+        }
+    }
+
+    #[inline]
+    pub fn source_map(&self) -> &SourceMap {
+        &self.source_map
+    }
+
+    pub fn buffer_lint(
+        &self,
+        lint_id: BufferedEarlyLintId,
+        span: impl Into<MultiSpan>,
+        id: NodeId,
+        msg: &str,
+    ) {
+        self.buffered_lints.with_lock(|buffered_lints| {
+            buffered_lints.push(BufferedEarlyLint{
+                span: span.into(),
+                id,
+                msg: msg.into(),
+                lint_id,
+            });
+        });
+    }
+
+    /// Extend an error with a suggestion to wrap an expression with parentheses to allow the
+    /// parser to continue parsing the following operation as part of the same expression.
+    pub fn expr_parentheses_needed(
+        &self,
+        err: &mut DiagnosticBuilder<'_>,
+        span: Span,
+        alt_snippet: Option<String>,
+    ) {
+        if let Some(snippet) = self.source_map().span_to_snippet(span).ok().or(alt_snippet) {
+            err.span_suggestion(
+                span,
+                "parentheses are required to parse this as an expression",
+                format!("({})", snippet),
+                Applicability::MachineApplicable,
+            );
+        }
+    }
+}