Move pretty-printer FixupContext to a module

Required for being able to make the fields private and force the use of
accessor methods, which will be added in the next commit.

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -3,11 +3,12 @@
 //! Note that HIR pretty printing is layered on top of this crate.
 
 mod expr;
+mod fixup;
 mod item;
 
 use crate::pp::Breaks::{Consistent, Inconsistent};
 use crate::pp::{self, Breaks};
-use crate::pprust::state::expr::FixupContext;
+use crate::pprust::state::fixup::FixupContext;
 use ast::TraitBoundModifiers;
 use rustc_ast::attr::AttrIdGenerator;
 use rustc_ast::ptr::P;

compiler/rustc_ast_pretty/src/pprust/state/expr.rs

@@ -1,4 +1,5 @@
 use crate::pp::Breaks::Inconsistent;
+use crate::pprust::state::fixup::FixupContext;
 use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
 use ast::{ForLoopKind, MatchKind};
 use itertools::{Itertools, Position};
@@ -14,78 +15,6 @@ use rustc_ast::{
 };
 use std::fmt::Write;
 
-#[derive(Copy, Clone, Debug)]
-pub(crate) struct FixupContext {
-    /// Print expression such that it can be parsed back as a statement
-    /// consisting of the original expression.
-    ///
-    /// The effect of this is for binary operators in statement position to set
-    /// `leftmost_subexpression_in_stmt` when printing their left-hand operand.
-    ///
-    /// ```ignore (illustrative)
-    /// (match x {}) - 1;  // match needs parens when LHS of binary operator
-    ///
-    /// match x {};  // not when its own statement
-    /// ```
-    pub stmt: bool,
-
-    /// This is the difference between:
-    ///
-    /// ```ignore (illustrative)
-    /// (match x {}) - 1;  // subexpression needs parens
-    ///
-    /// let _ = match x {} - 1;  // no parens
-    /// ```
-    ///
-    /// There are 3 distinguishable contexts in which `print_expr` might be
-    /// called with the expression `$match` as its argument, where `$match`
-    /// represents an expression of kind `ExprKind::Match`:
-    ///
-    ///   - stmt=false leftmost_subexpression_in_stmt=false
-    ///
-    ///     Example: `let _ = $match - 1;`
-    ///
-    ///     No parentheses required.
-    ///
-    ///   - stmt=false leftmost_subexpression_in_stmt=true
-    ///
-    ///     Example: `$match - 1;`
-    ///
-    ///     Must parenthesize `($match)`, otherwise parsing back the output as a
-    ///     statement would terminate the statement after the closing brace of
-    ///     the match, parsing `-1;` as a separate statement.
-    ///
-    ///   - stmt=true leftmost_subexpression_in_stmt=false
-    ///
-    ///     Example: `$match;`
-    ///
-    ///     No parentheses required.
-    pub leftmost_subexpression_in_stmt: bool,
-
-    /// This is the difference between:
-    ///
-    /// ```ignore (illustrative)
-    /// if let _ = (Struct {}) {}  // needs parens
-    ///
-    /// match () {
-    ///     () if let _ = Struct {} => {}  // no parens
-    /// }
-    /// ```
-    pub parenthesize_exterior_struct_lit: bool,
-}
-
-/// The default amount of fixing is minimal fixing. Fixups should be turned on
-/// in a targeted fashion where needed.
-impl Default for FixupContext {
-    fn default() -> Self {
-        FixupContext {
-            stmt: false,
-            leftmost_subexpression_in_stmt: false,
-            parenthesize_exterior_struct_lit: false,
-        }
-    }
-}
-
 impl<'a> State<'a> {
     fn print_else(&mut self, els: Option<&ast::Expr>) {
         if let Some(_else) = els {

compiler/rustc_ast_pretty/src/pprust/state/fixup.rs

@@ -0,0 +1,71 @@
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct FixupContext {
+    /// Print expression such that it can be parsed back as a statement
+    /// consisting of the original expression.
+    ///
+    /// The effect of this is for binary operators in statement position to set
+    /// `leftmost_subexpression_in_stmt` when printing their left-hand operand.
+    ///
+    /// ```ignore (illustrative)
+    /// (match x {}) - 1;  // match needs parens when LHS of binary operator
+    ///
+    /// match x {};  // not when its own statement
+    /// ```
+    pub stmt: bool,
+
+    /// This is the difference between:
+    ///
+    /// ```ignore (illustrative)
+    /// (match x {}) - 1;  // subexpression needs parens
+    ///
+    /// let _ = match x {} - 1;  // no parens
+    /// ```
+    ///
+    /// There are 3 distinguishable contexts in which `print_expr` might be
+    /// called with the expression `$match` as its argument, where `$match`
+    /// represents an expression of kind `ExprKind::Match`:
+    ///
+    ///   - stmt=false leftmost_subexpression_in_stmt=false
+    ///
+    ///     Example: `let _ = $match - 1;`
+    ///
+    ///     No parentheses required.
+    ///
+    ///   - stmt=false leftmost_subexpression_in_stmt=true
+    ///
+    ///     Example: `$match - 1;`
+    ///
+    ///     Must parenthesize `($match)`, otherwise parsing back the output as a
+    ///     statement would terminate the statement after the closing brace of
+    ///     the match, parsing `-1;` as a separate statement.
+    ///
+    ///   - stmt=true leftmost_subexpression_in_stmt=false
+    ///
+    ///     Example: `$match;`
+    ///
+    ///     No parentheses required.
+    pub leftmost_subexpression_in_stmt: bool,
+
+    /// This is the difference between:
+    ///
+    /// ```ignore (illustrative)
+    /// if let _ = (Struct {}) {}  // needs parens
+    ///
+    /// match () {
+    ///     () if let _ = Struct {} => {}  // no parens
+    /// }
+    /// ```
+    pub parenthesize_exterior_struct_lit: bool,
+}
+
+/// The default amount of fixing is minimal fixing. Fixups should be turned on
+/// in a targeted fashion where needed.
+impl Default for FixupContext {
+    fn default() -> Self {
+        FixupContext {
+            stmt: false,
+            leftmost_subexpression_in_stmt: false,
+            parenthesize_exterior_struct_lit: false,
+        }
+    }
+}

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -1,5 +1,5 @@
 use crate::pp::Breaks::Inconsistent;
-use crate::pprust::state::expr::FixupContext;
+use crate::pprust::state::fixup::FixupContext;
 use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
 
 use ast::StaticItem;