Rollup merge of rust-lang#129929 - nnethercote:rustc_mir_transform-cleanups-2, r=cjgillot

`rustc_mir_transform` cleanups, round 2

More cleanups in the style of rust-lang#129738.

r? `@cjgillot`

Author: matthiaskrgr

compiler/rustc_mir_transform/src/abort_unwinding_calls.rs

@@ -20,7 +20,7 @@ use rustc_target::spec::PanicStrategy;
 /// This forces all unwinds, in panic=abort mode happening in foreign code, to
 /// trigger a process abort.
 #[derive(PartialEq)]
-pub struct AbortUnwindingCalls;
+pub(super) struct AbortUnwindingCalls;
 
 impl<'tcx> crate::MirPass<'tcx> for AbortUnwindingCalls {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
@@ -50,9 +50,7 @@ impl<'tcx> crate::MirPass<'tcx> for AbortUnwindingCalls {
         // with a function call, and whose function we're calling may unwind.
         // This will filter to functions with `extern "C-unwind"` ABIs, for
         // example.
-        let mut calls_to_terminate = Vec::new();
-        let mut cleanups_to_remove = Vec::new();
-        for (id, block) in body.basic_blocks.iter_enumerated() {
+        for block in body.basic_blocks.as_mut() {
             if block.is_cleanup {
                 continue;
             }
@@ -61,7 +59,7 @@ impl<'tcx> crate::MirPass<'tcx> for AbortUnwindingCalls {
 
             let call_can_unwind = match &terminator.kind {
                 TerminatorKind::Call { func, .. } => {
-                    let ty = func.ty(body, tcx);
+                    let ty = func.ty(&body.local_decls, tcx);
                     let sig = ty.fn_sig(tcx);
                     let fn_def_id = match ty.kind() {
                         ty::FnPtr(..) => None,
@@ -86,33 +84,22 @@ impl<'tcx> crate::MirPass<'tcx> for AbortUnwindingCalls {
                 _ => continue,
             };
 
-            // If this function call can't unwind, then there's no need for it
-            // to have a landing pad. This means that we can remove any cleanup
-            // registered for it.
             if !call_can_unwind {
-                cleanups_to_remove.push(id);
-                continue;
-            }
-
-            // Otherwise if this function can unwind, then if the outer function
-            // can also unwind there's nothing to do. If the outer function
-            // can't unwind, however, we need to change the landing pad for this
-            // function call to one that aborts.
-            if !body_can_unwind {
-                calls_to_terminate.push(id);
+                // If this function call can't unwind, then there's no need for it
+                // to have a landing pad. This means that we can remove any cleanup
+                // registered for it.
+                let cleanup = block.terminator_mut().unwind_mut().unwrap();
+                *cleanup = UnwindAction::Unreachable;
+            } else if !body_can_unwind {
+                // Otherwise if this function can unwind, then if the outer function
+                // can also unwind there's nothing to do. If the outer function
+                // can't unwind, however, we need to change the landing pad for this
+                // function call to one that aborts.
+                let cleanup = block.terminator_mut().unwind_mut().unwrap();
+                *cleanup = UnwindAction::Terminate(UnwindTerminateReason::Abi);
             }
         }
 
-        for id in calls_to_terminate {
-            let cleanup = body.basic_blocks_mut()[id].terminator_mut().unwind_mut().unwrap();
-            *cleanup = UnwindAction::Terminate(UnwindTerminateReason::Abi);
-        }
-
-        for id in cleanups_to_remove {
-            let cleanup = body.basic_blocks_mut()[id].terminator_mut().unwind_mut().unwrap();
-            *cleanup = UnwindAction::Unreachable;
-        }
-
         // We may have invalidated some `cleanup` blocks so clean those up now.
         super::simplify::remove_dead_blocks(body);
     }

compiler/rustc_mir_transform/src/add_call_guards.rs

@@ -4,11 +4,11 @@ use rustc_middle::ty::TyCtxt;
 use tracing::debug;
 
 #[derive(PartialEq)]
-pub enum AddCallGuards {
+pub(super) enum AddCallGuards {
     AllCallEdges,
     CriticalCallEdges,
 }
-pub use self::AddCallGuards::*;
+pub(super) use self::AddCallGuards::*;
 
 /**
  * Breaks outgoing critical edges for call terminators in the MIR.
@@ -37,7 +37,7 @@ impl<'tcx> crate::MirPass<'tcx> for AddCallGuards {
 }
 
 impl AddCallGuards {
-    pub fn add_call_guards(&self, body: &mut Body<'_>) {
+    pub(super) fn add_call_guards(&self, body: &mut Body<'_>) {
         let mut pred_count: IndexVec<_, _> =
             body.basic_blocks.predecessors().iter().map(|ps| ps.len()).collect();
         pred_count[START_BLOCK] += 1;

compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs

@@ -35,7 +35,7 @@ use crate::util;
 ///
 /// The storage instructions are required to avoid stack space
 /// blowup.
-pub struct AddMovesForPackedDrops;
+pub(super) struct AddMovesForPackedDrops;
 
 impl<'tcx> crate::MirPass<'tcx> for AddMovesForPackedDrops {
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
@@ -44,7 +44,7 @@ impl<'tcx> crate::MirPass<'tcx> for AddMovesForPackedDrops {
     }
 }
 
-pub fn add_moves_for_packed_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+fn add_moves_for_packed_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
     let patch = add_moves_for_packed_drops_patch(tcx, body);
     patch.apply(body);
 }

compiler/rustc_mir_transform/src/add_retag.rs

@@ -8,7 +8,7 @@ use rustc_hir::LangItem;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 
-pub struct AddRetag;
+pub(super) struct AddRetag;
 
 /// Determine whether this type may contain a reference (or box), and thus needs retagging.
 /// We will only recurse `depth` times into Tuples/ADTs to bound the cost of this.

compiler/rustc_mir_transform/src/add_subtyping_projections.rs

@@ -1,15 +1,14 @@
-use rustc_index::IndexVec;
 use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::visit::MutVisitor;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 
-pub struct Subtyper;
+pub(super) struct Subtyper;
 
-pub struct SubTypeChecker<'a, 'tcx> {
+struct SubTypeChecker<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     patcher: MirPatch<'tcx>,
-    local_decls: &'a IndexVec<Local, LocalDecl<'tcx>>,
+    local_decls: &'a LocalDecls<'tcx>,
 }
 
 impl<'a, 'tcx> MutVisitor<'tcx> for SubTypeChecker<'a, 'tcx> {
@@ -52,7 +51,7 @@ impl<'a, 'tcx> MutVisitor<'tcx> for SubTypeChecker<'a, 'tcx> {
 // // gets transformed to
 // let temp: rval_ty = rval;
 // let place: place_ty = temp as place_ty;
-pub fn subtype_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+fn subtype_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
     let patch = MirPatch::new(body);
     let mut checker = SubTypeChecker { tcx, patcher: patch, local_decls: &body.local_decls };
 

compiler/rustc_mir_transform/src/check_alignment.rs

@@ -7,7 +7,7 @@ use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
 use rustc_session::Session;
 use tracing::{debug, trace};
 
-pub struct CheckAlignment;
+pub(super) struct CheckAlignment;
 
 impl<'tcx> crate::MirPass<'tcx> for CheckAlignment {
     fn is_enabled(&self, sess: &Session) -> bool {

compiler/rustc_mir_transform/src/check_const_item_mutation.rs

@@ -8,7 +8,7 @@ use rustc_span::Span;
 
 use crate::errors;
 
-pub struct CheckConstItemMutation;
+pub(super) struct CheckConstItemMutation;
 
 impl<'tcx> crate::MirLint<'tcx> for CheckConstItemMutation {
     fn run_lint(&self, tcx: TyCtxt<'tcx>, body: &Body<'tcx>) {

compiler/rustc_mir_transform/src/check_packed_ref.rs

@@ -5,7 +5,7 @@ use rustc_middle::ty::{self, TyCtxt};
 
 use crate::{errors, util};
 
-pub struct CheckPackedRef;
+pub(super) struct CheckPackedRef;
 
 impl<'tcx> crate::MirLint<'tcx> for CheckPackedRef {
     fn run_lint(&self, tcx: TyCtxt<'tcx>, body: &Body<'tcx>) {

compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs

@@ -21,7 +21,7 @@ use rustc_middle::mir::{Body, BorrowKind, CastKind, Rvalue, StatementKind, Termi
 use rustc_middle::ty::adjustment::PointerCoercion;
 use rustc_middle::ty::TyCtxt;
 
-pub struct CleanupPostBorrowck;
+pub(super) struct CleanupPostBorrowck;
 
 impl<'tcx> crate::MirPass<'tcx> for CleanupPostBorrowck {
     fn run_pass(&self, _tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {

compiler/rustc_mir_transform/src/copy_prop.rs

@@ -17,7 +17,7 @@ use crate::ssa::SsaLocals;
 /// where each of the locals is only assigned once.
 ///
 /// We want to replace all those locals by `_a`, either copied or moved.
-pub struct CopyProp;
+pub(super) struct CopyProp;
 
 impl<'tcx> crate::MirPass<'tcx> for CopyProp {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {

compiler/rustc_mir_transform/src/coroutine.rs

@@ -53,7 +53,7 @@
 mod by_move_body;
 use std::{iter, ops};
 
-pub use by_move_body::coroutine_by_move_body_def_id;
+pub(super) use by_move_body::coroutine_by_move_body_def_id;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::pluralize;
 use rustc_hir as hir;
@@ -85,7 +85,7 @@ use tracing::{debug, instrument, trace};
 use crate::deref_separator::deref_finder;
 use crate::{abort_unwinding_calls, errors, pass_manager as pm, simplify};
 
-pub struct StateTransform;
+pub(super) struct StateTransform;
 
 struct RenameLocalVisitor<'tcx> {
     from: Local,
@@ -1199,7 +1199,7 @@ fn insert_panic_block<'tcx>(
     message: AssertMessage<'tcx>,
 ) -> BasicBlock {
     let assert_block = BasicBlock::new(body.basic_blocks.len());
-    let term = TerminatorKind::Assert {
+    let kind = TerminatorKind::Assert {
         cond: Operand::Constant(Box::new(ConstOperand {
             span: body.span,
             user_ty: None,
@@ -1211,14 +1211,7 @@ fn insert_panic_block<'tcx>(
         unwind: UnwindAction::Continue,
     };
 
-    let source_info = SourceInfo::outermost(body.span);
-    body.basic_blocks_mut().push(BasicBlockData {
-        statements: Vec::new(),
-        terminator: Some(Terminator { source_info, kind: term }),
-        is_cleanup: false,
-    });
-
-    assert_block
+    insert_term_block(body, kind)
 }
 
 fn can_return<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {

compiler/rustc_mir_transform/src/coroutine/by_move_body.rs

@@ -82,7 +82,7 @@ use rustc_middle::ty::{self, InstanceKind, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::symbol::kw;
 use rustc_target::abi::{FieldIdx, VariantIdx};
 
-pub fn coroutine_by_move_body_def_id<'tcx>(
+pub(crate) fn coroutine_by_move_body_def_id<'tcx>(
     tcx: TyCtxt<'tcx>,
     coroutine_def_id: LocalDefId,
 ) -> DefId {

compiler/rustc_mir_transform/src/cost_checker.rs

@@ -12,7 +12,7 @@ const CONST_SWITCH_BONUS: usize = 10;
 
 /// Verify that the callee body is compatible with the caller.
 #[derive(Clone)]
-pub(crate) struct CostChecker<'b, 'tcx> {
+pub(super) struct CostChecker<'b, 'tcx> {
     tcx: TyCtxt<'tcx>,
     param_env: ParamEnv<'tcx>,
     penalty: usize,
@@ -22,7 +22,7 @@ pub(crate) struct CostChecker<'b, 'tcx> {
 }
 
 impl<'b, 'tcx> CostChecker<'b, 'tcx> {
-    pub fn new(
+    pub(super) fn new(
         tcx: TyCtxt<'tcx>,
         param_env: ParamEnv<'tcx>,
         instance: Option<ty::Instance<'tcx>>,
@@ -36,7 +36,7 @@ impl<'b, 'tcx> CostChecker<'b, 'tcx> {
     /// Needed because the `CostChecker` is used sometimes for just blocks,
     /// and even the full `Inline` doesn't call `visit_body`, so there's nowhere
     /// to put this logic in the visitor.
-    pub fn add_function_level_costs(&mut self) {
+    pub(super) fn add_function_level_costs(&mut self) {
         fn is_call_like(bbd: &BasicBlockData<'_>) -> bool {
             use TerminatorKind::*;
             match bbd.terminator().kind {
@@ -64,7 +64,7 @@ impl<'b, 'tcx> CostChecker<'b, 'tcx> {
         }
     }
 
-    pub fn cost(&self) -> usize {
+    pub(super) fn cost(&self) -> usize {
         usize::saturating_sub(self.penalty, self.bonus)
     }
 

compiler/rustc_mir_transform/src/coverage/mod.rs

@@ -1,4 +1,4 @@
-pub mod query;
+pub(super) mod query;
 
 mod counters;
 mod graph;
@@ -32,7 +32,7 @@ use crate::coverage::mappings::ExtractedMappings;
 /// Inserts `StatementKind::Coverage` statements that either instrument the binary with injected
 /// counters, via intrinsic `llvm.instrprof.increment`, and/or inject metadata used during codegen
 /// to construct the coverage map.
-pub struct InstrumentCoverage;
+pub(super) struct InstrumentCoverage;
 
 impl<'tcx> crate::MirPass<'tcx> for InstrumentCoverage {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {

compiler/rustc_mir_transform/src/cross_crate_inline.rs

@@ -10,7 +10,7 @@ use rustc_span::sym;
 
 use crate::{inline, pass_manager as pm};
 
-pub fn provide(providers: &mut Providers) {
+pub(super) fn provide(providers: &mut Providers) {
     providers.cross_crate_inlinable = cross_crate_inlinable;
 }
 

compiler/rustc_mir_transform/src/ctfe_limit.rs

@@ -8,7 +8,7 @@ use rustc_middle::mir::{
 use rustc_middle::ty::TyCtxt;
 use tracing::instrument;
 
-pub struct CtfeLimit;
+pub(super) struct CtfeLimit;
 
 impl<'tcx> crate::MirPass<'tcx> for CtfeLimit {
     #[instrument(skip(self, _tcx, body))]

compiler/rustc_mir_transform/src/dataflow_const_prop.rs

@@ -26,7 +26,7 @@ use tracing::{debug, debug_span, instrument};
 const BLOCK_LIMIT: usize = 100;
 const PLACE_LIMIT: usize = 100;
 
-pub struct DataflowConstProp;
+pub(super) struct DataflowConstProp;
 
 impl<'tcx> crate::MirPass<'tcx> for DataflowConstProp {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
@@ -332,7 +332,7 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> {
 }
 
 impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, map: Map<'tcx>) -> Self {
+    fn new(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, map: Map<'tcx>) -> Self {
         let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
         Self {
             map,

compiler/rustc_mir_transform/src/dead_store_elimination.rs

@@ -28,7 +28,7 @@ use crate::util::is_within_packed;
 ///
 /// The `borrowed` set must be a `BitSet` of all the locals that are ever borrowed in this body. It
 /// can be generated via the [`borrowed_locals`] function.
-pub fn eliminate<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+fn eliminate<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
     let borrowed_locals = borrowed_locals(body);
 
     // If the user requests complete debuginfo, mark the locals that appear in it as live, so
@@ -127,7 +127,7 @@ pub fn eliminate<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
     }
 }
 
-pub enum DeadStoreElimination {
+pub(super) enum DeadStoreElimination {
     Initial,
     Final,
 }

compiler/rustc_mir_transform/src/deduce_param_attrs.rs

@@ -150,7 +150,7 @@ fn type_will_always_be_passed_directly(ty: Ty<'_>) -> bool {
 /// body of the function instead of just the signature. These can be useful for optimization
 /// purposes on a best-effort basis. We compute them here and store them into the crate metadata so
 /// dependent crates can use them.
-pub fn deduced_param_attrs<'tcx>(
+pub(super) fn deduced_param_attrs<'tcx>(
     tcx: TyCtxt<'tcx>,
     def_id: LocalDefId,
 ) -> &'tcx [DeducedParamAttrs] {

compiler/rustc_mir_transform/src/deduplicate_blocks.rs

@@ -13,7 +13,7 @@ use tracing::debug;
 
 use super::simplify::simplify_cfg;
 
-pub struct DeduplicateBlocks;
+pub(super) struct DeduplicateBlocks;
 
 impl<'tcx> crate::MirPass<'tcx> for DeduplicateBlocks {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {