Rollup merge of #136336 - nnethercote:overhaul-rustc_middle-util, r=jieyouxu

Overhaul `rustc_middle::util`

It's an odd module with some odd stuff in it.

r? `@Noratrieb`

8 files changed, 54 insertions, 115 deletions

diff --git a/compiler/rustc_middle/src/macros.rs b/compiler/rustc_middle/src/macros.rs
index 39816c17b98..b3064d8fe25 100644
--- a/compiler/rustc_middle/src/macros.rs
+++ b/compiler/rustc_middle/src/macros.rs
@@ -4,8 +4,8 @@
 ///
 /// If you have a span available, you should use [`span_bug`] instead.
 ///
-/// If the bug should only be emitted when compilation didn't fail, [`DiagCtxtHandle::span_delayed_bug`]
-/// may be useful.
+/// If the bug should only be emitted when compilation didn't fail,
+/// [`DiagCtxtHandle::span_delayed_bug`] may be useful.
 ///
 /// [`DiagCtxtHandle::span_delayed_bug`]: rustc_errors::DiagCtxtHandle::span_delayed_bug
 /// [`span_bug`]: crate::span_bug
@@ -14,14 +14,8 @@ macro_rules! bug {
     () => (
         $crate::bug!("impossible case reached")
     );
-    ($msg:expr) => (
-        $crate::util::bug::bug_fmt(::std::format_args!($msg))
-    );
-    ($msg:expr,) => (
-        $crate::bug!($msg)
-    );
-    ($fmt:expr, $($arg:tt)+) => (
-        $crate::util::bug::bug_fmt(::std::format_args!($fmt, $($arg)+))
+    ($($arg:tt)+) => (
+        $crate::util::bug::bug_fmt(::std::format_args!($($arg)+))
     );
 }
 
@@ -30,20 +24,14 @@ macro_rules! bug {
 /// at the code the compiler was compiling when it ICEd. This is the preferred way to trigger
 /// ICEs.
 ///
-/// If the bug should only be emitted when compilation didn't fail, [`DiagCtxtHandle::span_delayed_bug`]
-/// may be useful.
+/// If the bug should only be emitted when compilation didn't fail,
+/// [`DiagCtxtHandle::span_delayed_bug`] may be useful.
 ///
 /// [`DiagCtxtHandle::span_delayed_bug`]: rustc_errors::DiagCtxtHandle::span_delayed_bug
 #[macro_export]
 macro_rules! span_bug {
-    ($span:expr, $msg:expr) => (
-        $crate::util::bug::span_bug_fmt($span, ::std::format_args!($msg))
-    );
-    ($span:expr, $msg:expr,) => (
-        $crate::span_bug!($span, $msg)
-    );
-    ($span:expr, $fmt:expr, $($arg:tt)+) => (
-        $crate::util::bug::span_bug_fmt($span, ::std::format_args!($fmt, $($arg)+))
+    ($span:expr, $($arg:tt)+) => (
+        $crate::util::bug::span_bug_fmt($span, ::std::format_args!($($arg)+))
     );
 }
 
@@ -53,7 +41,6 @@ macro_rules! span_bug {
 // When possible, use one of these (relatively) convenient macros to write
 // the impls for you.
 
-#[macro_export]
 macro_rules! TrivialLiftImpls {
     ($($ty:ty),+ $(,)?) => {
         $(
@@ -69,7 +56,6 @@ macro_rules! TrivialLiftImpls {
 
 /// Used for types that are `Copy` and which **do not care about arena
 /// allocated data** (i.e., don't need to be folded).
-#[macro_export]
 macro_rules! TrivialTypeTraversalImpls {
     ($($ty:ty),+ $(,)?) => {
         $(
@@ -104,7 +90,6 @@ macro_rules! TrivialTypeTraversalImpls {
     };
 }
 
-#[macro_export]
 macro_rules! TrivialTypeTraversalAndLiftImpls {
     ($($t:tt)*) => {
         TrivialTypeTraversalImpls! { $($t)* }
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 0f3fca434ee..cfb78e5dddf 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -27,7 +27,7 @@ use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisit
 use rustc_serialize::{Decodable, Encodable};
 use rustc_span::source_map::Spanned;
 use rustc_span::{DUMMY_SP, Span, Symbol};
-use tracing::trace;
+use tracing::{debug, trace};
 
 pub use self::query::*;
 use self::visit::TyContext;
@@ -1796,6 +1796,47 @@ impl DefLocation {
     }
 }
 
+/// Checks if the specified `local` is used as the `self` parameter of a method call
+/// in the provided `BasicBlock`. If it is, then the `DefId` of the called method is
+/// returned.
+pub fn find_self_call<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    body: &Body<'tcx>,
+    local: Local,
+    block: BasicBlock,
+) -> Option<(DefId, GenericArgsRef<'tcx>)> {
+    debug!("find_self_call(local={:?}): terminator={:?}", local, body[block].terminator);
+    if let Some(Terminator { kind: TerminatorKind::Call { func, args, .. }, .. }) =
+        &body[block].terminator
+        && let Operand::Constant(box ConstOperand { const_, .. }) = func
+        && let ty::FnDef(def_id, fn_args) = *const_.ty().kind()
+        && let Some(ty::AssocItem { fn_has_self_parameter: true, .. }) =
+            tcx.opt_associated_item(def_id)
+        && let [Spanned { node: Operand::Move(self_place) | Operand::Copy(self_place), .. }, ..] =
+            **args
+    {
+        if self_place.as_local() == Some(local) {
+            return Some((def_id, fn_args));
+        }
+
+        // Handle the case where `self_place` gets reborrowed.
+        // This happens when the receiver is `&T`.
+        for stmt in &body[block].statements {
+            if let StatementKind::Assign(box (place, rvalue)) = &stmt.kind
+                && let Some(reborrow_local) = place.as_local()
+                && self_place.as_local() == Some(reborrow_local)
+                && let Rvalue::Ref(_, _, deref_place) = rvalue
+                && let PlaceRef { local: deref_local, projection: [ProjectionElem::Deref] } =
+                    deref_place.as_ref()
+                && deref_local == local
+            {
+                return Some((def_id, fn_args));
+            }
+        }
+    }
+    None
+}
+
 // Some nodes are used a lot. Make sure they don't unintentionally get bigger.
 #[cfg(target_pointer_width = "64")]
 mod size_asserts {
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 8a9110f842a..28a6eba75aa 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -428,7 +428,7 @@ pub enum IsConstable {
     Ctor,
 }
 
-crate::TrivialTypeTraversalAndLiftImpls! {
+TrivialTypeTraversalAndLiftImpls! {
     IsConstable,
 }
 
diff --git a/compiler/rustc_middle/src/util/bug.rs b/compiler/rustc_middle/src/util/bug.rs
index b99336c2c85..7dda68b8393 100644
--- a/compiler/rustc_middle/src/util/bug.rs
+++ b/compiler/rustc_middle/src/util/bug.rs
@@ -1,4 +1,4 @@
-// These functions are used by macro expansion for bug! and span_bug!
+// These functions are used by macro expansion for `bug!` and `span_bug!`.
 
 use std::fmt;
 use std::panic::{Location, panic_any};
@@ -8,15 +8,15 @@ use rustc_span::Span;
 
 use crate::ty::{TyCtxt, tls};
 
+// This wrapper makes for more compact code at callsites than calling `opt_span_buf_fmt` directly.
 #[cold]
 #[inline(never)]
 #[track_caller]
 pub fn bug_fmt(args: fmt::Arguments<'_>) -> ! {
-    // this wrapper mostly exists so I don't have to write a fully
-    // qualified path of None::<Span> inside the bug!() macro definition
     opt_span_bug_fmt(None::<Span>, args, Location::caller());
 }
 
+// This wrapper makes for more compact code at callsites than calling `opt_span_buf_fmt` directly.
 #[cold]
 #[inline(never)]
 #[track_caller]
diff --git a/compiler/rustc_middle/src/util/common.rs b/compiler/rustc_middle/src/util/common.rs
deleted file mode 100644
index 223b2b3bfe4..00000000000
--- a/compiler/rustc_middle/src/util/common.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-#[cfg(test)]
-mod tests;
-
-pub fn to_readable_str(mut val: usize) -> String {
-    let mut groups = vec![];
-    loop {
-        let group = val % 1000;
-
-        val /= 1000;
-
-        if val == 0 {
-            groups.push(group.to_string());
-            break;
-        } else {
-            groups.push(format!("{group:03}"));
-        }
-    }
-
-    groups.reverse();
-
-    groups.join("_")
-}
diff --git a/compiler/rustc_middle/src/util/common/tests.rs b/compiler/rustc_middle/src/util/common/tests.rs
deleted file mode 100644
index 9a9fb203c62..00000000000
--- a/compiler/rustc_middle/src/util/common/tests.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-use super::*;
-
-#[test]
-fn test_to_readable_str() {
-    assert_eq!("0", to_readable_str(0));
-    assert_eq!("1", to_readable_str(1));
-    assert_eq!("99", to_readable_str(99));
-    assert_eq!("999", to_readable_str(999));
-    assert_eq!("1_000", to_readable_str(1_000));
-    assert_eq!("1_001", to_readable_str(1_001));
-    assert_eq!("999_999", to_readable_str(999_999));
-    assert_eq!("1_000_000", to_readable_str(1_000_000));
-    assert_eq!("1_234_567", to_readable_str(1_234_567));
-}
diff --git a/compiler/rustc_middle/src/util/find_self_call.rs b/compiler/rustc_middle/src/util/find_self_call.rs
deleted file mode 100644
index 0fdd3520738..00000000000
--- a/compiler/rustc_middle/src/util/find_self_call.rs
+++ /dev/null
@@ -1,47 +0,0 @@
-use rustc_span::def_id::DefId;
-use rustc_span::source_map::Spanned;
-use tracing::debug;
-
-use crate::mir::*;
-use crate::ty::{self, GenericArgsRef, TyCtxt};
-
-/// Checks if the specified `local` is used as the `self` parameter of a method call
-/// in the provided `BasicBlock`. If it is, then the `DefId` of the called method is
-/// returned.
-pub fn find_self_call<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    body: &Body<'tcx>,
-    local: Local,
-    block: BasicBlock,
-) -> Option<(DefId, GenericArgsRef<'tcx>)> {
-    debug!("find_self_call(local={:?}): terminator={:?}", local, body[block].terminator);
-    if let Some(Terminator { kind: TerminatorKind::Call { func, args, .. }, .. }) =
-        &body[block].terminator
-        && let Operand::Constant(box ConstOperand { const_, .. }) = func
-        && let ty::FnDef(def_id, fn_args) = *const_.ty().kind()
-        && let Some(ty::AssocItem { fn_has_self_parameter: true, .. }) =
-            tcx.opt_associated_item(def_id)
-        && let [Spanned { node: Operand::Move(self_place) | Operand::Copy(self_place), .. }, ..] =
-            **args
-    {
-        if self_place.as_local() == Some(local) {
-            return Some((def_id, fn_args));
-        }
-
-        // Handle the case where `self_place` gets reborrowed.
-        // This happens when the receiver is `&T`.
-        for stmt in &body[block].statements {
-            if let StatementKind::Assign(box (place, rvalue)) = &stmt.kind
-                && let Some(reborrow_local) = place.as_local()
-                && self_place.as_local() == Some(reborrow_local)
-                && let Rvalue::Ref(_, _, deref_place) = rvalue
-                && let PlaceRef { local: deref_local, projection: [ProjectionElem::Deref] } =
-                    deref_place.as_ref()
-                && deref_local == local
-            {
-                return Some((def_id, fn_args));
-            }
-        }
-    }
-    None
-}
diff --git a/compiler/rustc_middle/src/util/mod.rs b/compiler/rustc_middle/src/util/mod.rs
index 097a868191c..8c875007b7f 100644
--- a/compiler/rustc_middle/src/util/mod.rs
+++ b/compiler/rustc_middle/src/util/mod.rs
@@ -1,8 +1,4 @@
 pub mod bug;
-pub mod common;
-pub mod find_self_call;
-
-pub use find_self_call::find_self_call;
 
 #[derive(Default, Copy, Clone)]
 pub struct Providers {