Rename thir::cx::Cx to ThirBuildCx

Author: Zalathar

compiler/rustc_mir_build/src/thir/cx/block.rs

@@ -6,9 +6,9 @@ use rustc_middle::ty;
 use rustc_middle::ty::CanonicalUserTypeAnnotation;
 use tracing::debug;
 
-use crate::thir::cx::Cx;
+use crate::thir::cx::ThirBuildCx;
 
-impl<'tcx> Cx<'tcx> {
+impl<'tcx> ThirBuildCx<'tcx> {
     pub(crate) fn mirror_block(&mut self, block: &'tcx hir::Block<'tcx>) -> BlockId {
         // We have to eagerly lower the "spine" of the statements
         // in order to get the lexical scoping correctly.

compiler/rustc_mir_build/src/thir/cx/expr.rs

@@ -21,9 +21,9 @@ use rustc_middle::{bug, span_bug};
 use rustc_span::{Span, sym};
 use tracing::{debug, info, instrument, trace};
 
-use crate::thir::cx::Cx;
+use crate::thir::cx::ThirBuildCx;
 
-impl<'tcx> Cx<'tcx> {
+impl<'tcx> ThirBuildCx<'tcx> {
     /// Create a THIR expression for the given HIR expression. This expands all
     /// adjustments and directly adds the type information from the
     /// `typeck_results`. See the [dev-guide] for more details.

compiler/rustc_mir_build/src/thir/cx/mod.rs

@@ -17,13 +17,14 @@ use tracing::instrument;
 
 use crate::thir::pattern::pat_from_hir;
 
+/// Query implementation for [`TyCtxt::thir_body`].
 pub(crate) fn thir_body(
     tcx: TyCtxt<'_>,
     owner_def: LocalDefId,
 ) -> Result<(&Steal<Thir<'_>>, ExprId), ErrorGuaranteed> {
     let hir = tcx.hir();
     let body = hir.body_owned_by(owner_def);
-    let mut cx = Cx::new(tcx, owner_def);
+    let mut cx = ThirBuildCx::new(tcx, owner_def);
     if let Some(reported) = cx.typeck_results.tainted_by_errors {
         return Err(reported);
     }
@@ -51,8 +52,10 @@ pub(crate) fn thir_body(
     Ok((tcx.alloc_steal_thir(cx.thir), expr))
 }
 
-struct Cx<'tcx> {
+/// Context for lowering HIR to THIR for a single function body (or other kind of body).
+struct ThirBuildCx<'tcx> {
     tcx: TyCtxt<'tcx>,
+    /// The THIR data that this context is building.
     thir: Thir<'tcx>,
 
     typing_env: ty::TypingEnv<'tcx>,
@@ -68,8 +71,8 @@ struct Cx<'tcx> {
     body_owner: DefId,
 }
 
-impl<'tcx> Cx<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>, def: LocalDefId) -> Cx<'tcx> {
+impl<'tcx> ThirBuildCx<'tcx> {
+    fn new(tcx: TyCtxt<'tcx>, def: LocalDefId) -> Self {
         let typeck_results = tcx.typeck(def);
         let hir = tcx.hir();
         let hir_id = tcx.local_def_id_to_hir_id(def);
@@ -93,7 +96,7 @@ impl<'tcx> Cx<'tcx> {
             BodyTy::Const(typeck_results.node_type(hir_id))
         };
 
-        Cx {
+        Self {
             tcx,
             thir: Thir::new(body_type),
             // FIXME(#132279): We're in a body, we should use a typing