Remove the thir_{tree,flat} hooks.

They were downgraded from queries in rust-lang#123995 but they can just be
vanilla functions because they are not called in `rustc_middle`.

Author: nnethercote

compiler/rustc_driver_impl/src/pretty.rs

@@ -7,6 +7,7 @@ use rustc_ast_pretty::pprust as pprust_ast;
 use rustc_middle::bug;
 use rustc_middle::mir::{write_mir_graphviz, write_mir_pretty};
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_mir_build::thir::print::{thir_flat, thir_tree};
 use rustc_session::Session;
 use rustc_session::config::{OutFileName, PpHirMode, PpMode, PpSourceMode};
 use rustc_smir::rustc_internal::pretty::write_smir_pretty;
@@ -313,7 +314,7 @@ pub fn print<'tcx>(sess: &Session, ppm: PpMode, ex: PrintExtra<'tcx>) {
             tcx.dcx().abort_if_errors();
             debug!("pretty printing THIR tree");
             for did in tcx.hir().body_owners() {
-                let _ = writeln!(out, "{:?}:\n{}\n", did, tcx.thir_tree(did));
+                let _ = writeln!(out, "{:?}:\n{}\n", did, thir_tree(tcx, did));
             }
             out
         }
@@ -324,7 +325,7 @@ pub fn print<'tcx>(sess: &Session, ppm: PpMode, ex: PrintExtra<'tcx>) {
             tcx.dcx().abort_if_errors();
             debug!("pretty printing THIR flat");
             for did in tcx.hir().body_owners() {
-                let _ = writeln!(out, "{:?}:\n{}\n", did, tcx.thir_flat(did));
+                let _ = writeln!(out, "{:?}:\n{}\n", did, thir_flat(tcx, did));
             }
             out
         }

compiler/rustc_middle/src/hooks/mod.rs

@@ -99,12 +99,6 @@ declare_hooks! {
     /// Will fetch a DefId from a DefPathHash for a foreign crate.
     hook def_path_hash_to_def_id_extern(hash: DefPathHash, stable_crate_id: StableCrateId) -> DefId;
 
-    /// Create a THIR tree for debugging.
-    hook thir_tree(key: LocalDefId) -> String;
-
-    /// Create a list-like THIR representation for debugging.
-    hook thir_flat(key: LocalDefId) -> String;
-
     /// Returns `true` if we should codegen an instance in the local crate, or returns `false` if we
     /// can just link to the upstream crate and therefore don't need a mono item.
     ///

compiler/rustc_mir_build/src/lib.rs

@@ -18,7 +18,7 @@ mod builder;
 mod check_tail_calls;
 mod check_unsafety;
 mod errors;
-mod thir;
+pub mod thir;
 
 use rustc_middle::util::Providers;
 
@@ -33,6 +33,4 @@ pub fn provide(providers: &mut Providers) {
     providers.check_unsafety = check_unsafety::check_unsafety;
     providers.check_tail_calls = check_tail_calls::check_tail_calls;
     providers.thir_body = thir::cx::thir_body;
-    providers.hooks.thir_tree = thir::print::thir_tree;
-    providers.hooks.thir_flat = thir::print::thir_flat;
 }

compiler/rustc_mir_build/src/thir/mod.rs

@@ -7,5 +7,5 @@
 pub(crate) mod constant;
 pub(crate) mod cx;
 pub(crate) mod pattern;
-pub(crate) mod print;
+pub mod print;
 mod util;

compiler/rustc_mir_build/src/thir/print.rs

@@ -1,12 +1,13 @@
 use std::fmt::{self, Write};
 
-use rustc_middle::query::TyCtxtAt;
 use rustc_middle::thir::*;
 use rustc_middle::ty;
+use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::LocalDefId;
 
-pub(crate) fn thir_tree(tcx: TyCtxtAt<'_>, owner_def: LocalDefId) -> String {
-    match super::cx::thir_body(*tcx, owner_def) {
+/// Create a THIR tree for debugging.
+pub fn thir_tree(tcx: TyCtxt<'_>, owner_def: LocalDefId) -> String {
+    match super::cx::thir_body(tcx, owner_def) {
         Ok((thir, _)) => {
             let thir = thir.steal();
             let mut printer = ThirPrinter::new(&thir);
@@ -17,8 +18,9 @@ pub(crate) fn thir_tree(tcx: TyCtxtAt<'_>, owner_def: LocalDefId) -> String {
     }
 }
 
-pub(crate) fn thir_flat(tcx: TyCtxtAt<'_>, owner_def: LocalDefId) -> String {
-    match super::cx::thir_body(*tcx, owner_def) {
+/// Create a list-like THIR representation for debugging.
+pub fn thir_flat(tcx: TyCtxt<'_>, owner_def: LocalDefId) -> String {
+    match super::cx::thir_body(tcx, owner_def) {
         Ok((thir, _)) => format!("{:#?}", thir.steal()),
         Err(_) => "error".into(),
     }