Move MirPatch from rustc_middle to rustc_mir_transform.

Because it's only used in `rustc_mir_transform`. (Presumably it is
currently in `rustc_middle` because lots of other MIR-related stuff is,
but that's not a hard requirement.) And because `rustc_middle` is huge
and it's always good to make it smaller.

Author: nnethercote

compiler/rustc_middle/src/mir/mod.rs

@@ -49,7 +49,6 @@ pub mod generic_graphviz;
 pub mod graphviz;
 pub mod interpret;
 pub mod mono;
-pub mod patch;
 pub mod pretty;
 mod query;
 mod statement;

compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs

@@ -1,8 +1,8 @@
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, TyCtxt};
 use tracing::debug;
 
+use crate::patch::MirPatch;
 use crate::util;
 
 /// This pass moves values being dropped that are within a packed

compiler/rustc_mir_transform/src/add_subtyping_projections.rs

@@ -1,8 +1,9 @@
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::visit::MutVisitor;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 
+use crate::patch::MirPatch;
+
 pub(super) struct Subtyper;
 
 struct SubTypeChecker<'a, 'tcx> {

compiler/rustc_mir_transform/src/coroutine.rs

@@ -1061,9 +1061,8 @@ fn insert_switch<'tcx>(
 }
 
 fn elaborate_coroutine_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-    use rustc_middle::mir::patch::MirPatch;
-
     use crate::elaborate_drop::{Unwind, elaborate_drop};
+    use crate::patch::MirPatch;
     use crate::shim::DropShimElaborator;
 
     // Note that `elaborate_drops` only drops the upvars of a coroutine, and

compiler/rustc_mir_transform/src/deref_separator.rs

@@ -1,9 +1,10 @@
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::visit::NonUseContext::VarDebugInfo;
 use rustc_middle::mir::visit::{MutVisitor, PlaceContext};
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 
+use crate::patch::MirPatch;
+
 pub(super) struct Derefer;
 
 struct DerefChecker<'a, 'tcx> {

compiler/rustc_mir_transform/src/early_otherwise_branch.rs

@@ -1,11 +1,11 @@
 use std::fmt::Debug;
 
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{Ty, TyCtxt};
 use tracing::trace;
 
 use super::simplify::simplify_cfg;
+use crate::patch::MirPatch;
 
 /// This pass optimizes something like
 /// ```ignore (syntax-highlighting-only)

compiler/rustc_mir_transform/src/elaborate_box_derefs.rs

@@ -4,12 +4,13 @@
 
 use rustc_abi::FieldIdx;
 use rustc_hir::def_id::DefId;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::visit::MutVisitor;
 use rustc_middle::mir::*;
 use rustc_middle::span_bug;
 use rustc_middle::ty::{Ty, TyCtxt};
 
+use crate::patch::MirPatch;
+
 /// Constructs the types used when accessing a Box's pointer
 fn build_ptr_tys<'tcx>(
     tcx: TyCtxt<'tcx>,

compiler/rustc_mir_transform/src/elaborate_drop.rs

@@ -3,7 +3,6 @@ use std::{fmt, iter, mem};
 use rustc_abi::{FIRST_VARIANT, FieldIdx, VariantIdx};
 use rustc_hir::lang_items::LangItem;
 use rustc_index::Idx;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::span_bug;
 use rustc_middle::ty::adjustment::PointerCoercion;
@@ -13,6 +12,8 @@ use rustc_span::DUMMY_SP;
 use rustc_span::source_map::Spanned;
 use tracing::{debug, instrument};
 
+use crate::patch::MirPatch;
+
 /// Describes how/if a value should be dropped.
 #[derive(Debug)]
 pub(crate) enum DropStyle {

compiler/rustc_mir_transform/src/elaborate_drops.rs

@@ -3,7 +3,6 @@ use std::fmt;
 use rustc_abi::{FieldIdx, VariantIdx};
 use rustc_index::IndexVec;
 use rustc_index::bit_set::DenseBitSet;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_mir_dataflow::impls::{MaybeInitializedPlaces, MaybeUninitializedPlaces};
@@ -17,6 +16,7 @@ use tracing::{debug, instrument};
 
 use crate::deref_separator::deref_finder;
 use crate::elaborate_drop::{DropElaborator, DropFlagMode, DropStyle, Unwind, elaborate_drop};
+use crate::patch::MirPatch;
 
 /// During MIR building, Drop terminators are inserted in every place where a drop may occur.
 /// However, in this phase, the presence of these terminators does not guarantee that a destructor

compiler/rustc_mir_transform/src/lib.rs

@@ -54,6 +54,7 @@ mod errors;
 mod ffi_unwind_calls;
 mod lint;
 mod lint_tail_expr_drop_order;
+mod patch;
 mod shim;
 mod ssa;
 

compiler/rustc_mir_transform/src/match_branches.rs

@@ -2,14 +2,14 @@ use std::iter;
 
 use rustc_abi::Integer;
 use rustc_index::IndexSlice;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::ty::layout::{IntegerExt, TyAndLayout};
 use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt};
 use rustc_type_ir::TyKind::*;
 use tracing::instrument;
 
 use super::simplify::simplify_cfg;
+use crate::patch::MirPatch;
 
 pub(super) struct MatchBranchSimplification;
 

compiler/rustc_middle/src/mir/patch.rs compiler/rustc_mir_transform/src/patch.rs

@@ -1,11 +1,13 @@
+use rustc_index::{Idx, IndexVec};
+use rustc_middle::mir::*;
+use rustc_middle::ty::Ty;
+use rustc_span::Span;
 use tracing::debug;
 
-use crate::mir::*;
-
 /// This struct represents a patch to MIR, which can add
 /// new statements and basic blocks and patch over block
 /// terminators.
-pub struct MirPatch<'tcx> {
+pub(crate) struct MirPatch<'tcx> {
     patch_map: IndexVec<BasicBlock, Option<TerminatorKind<'tcx>>>,
     new_blocks: Vec<BasicBlockData<'tcx>>,
     new_statements: Vec<(Location, StatementKind<'tcx>)>,
@@ -22,7 +24,7 @@ pub struct MirPatch<'tcx> {
 }
 
 impl<'tcx> MirPatch<'tcx> {
-    pub fn new(body: &Body<'tcx>) -> Self {
+    pub(crate) fn new(body: &Body<'tcx>) -> Self {
         let mut result = MirPatch {
             patch_map: IndexVec::from_elem(None, &body.basic_blocks),
             new_blocks: vec![],
@@ -69,7 +71,7 @@ impl<'tcx> MirPatch<'tcx> {
         result
     }
 
-    pub fn resume_block(&mut self) -> BasicBlock {
+    pub(crate) fn resume_block(&mut self) -> BasicBlock {
         if let Some(bb) = self.resume_block {
             return bb;
         }
@@ -86,7 +88,7 @@ impl<'tcx> MirPatch<'tcx> {
         bb
     }
 
-    pub fn unreachable_cleanup_block(&mut self) -> BasicBlock {
+    pub(crate) fn unreachable_cleanup_block(&mut self) -> BasicBlock {
         if let Some(bb) = self.unreachable_cleanup_block {
             return bb;
         }
@@ -103,7 +105,7 @@ impl<'tcx> MirPatch<'tcx> {
         bb
     }
 
-    pub fn unreachable_no_cleanup_block(&mut self) -> BasicBlock {
+    pub(crate) fn unreachable_no_cleanup_block(&mut self) -> BasicBlock {
         if let Some(bb) = self.unreachable_no_cleanup_block {
             return bb;
         }
@@ -120,7 +122,7 @@ impl<'tcx> MirPatch<'tcx> {
         bb
     }
 
-    pub fn terminate_block(&mut self, reason: UnwindTerminateReason) -> BasicBlock {
+    pub(crate) fn terminate_block(&mut self, reason: UnwindTerminateReason) -> BasicBlock {
         if let Some((cached_bb, cached_reason)) = self.terminate_block
             && reason == cached_reason
         {
@@ -139,19 +141,11 @@ impl<'tcx> MirPatch<'tcx> {
         bb
     }
 
-    pub fn is_patched(&self, bb: BasicBlock) -> bool {
+    pub(crate) fn is_patched(&self, bb: BasicBlock) -> bool {
         self.patch_map[bb].is_some()
     }
 
-    pub fn terminator_loc(&self, body: &Body<'tcx>, bb: BasicBlock) -> Location {
-        let offset = match bb.index().checked_sub(body.basic_blocks.len()) {
-            Some(index) => self.new_blocks[index].statements.len(),
-            None => body[bb].statements.len(),
-        };
-        Location { block: bb, statement_index: offset }
-    }
-
-    pub fn new_local_with_info(
+    pub(crate) fn new_local_with_info(
         &mut self,
         ty: Ty<'tcx>,
         span: Span,
@@ -165,37 +159,37 @@ impl<'tcx> MirPatch<'tcx> {
         Local::new(index)
     }
 
-    pub fn new_temp(&mut self, ty: Ty<'tcx>, span: Span) -> Local {
+    pub(crate) fn new_temp(&mut self, ty: Ty<'tcx>, span: Span) -> Local {
         let index = self.next_local;
         self.next_local += 1;
         self.new_locals.push(LocalDecl::new(ty, span));
         Local::new(index)
     }
 
-    pub fn new_block(&mut self, data: BasicBlockData<'tcx>) -> BasicBlock {
+    pub(crate) fn new_block(&mut self, data: BasicBlockData<'tcx>) -> BasicBlock {
         let block = BasicBlock::new(self.patch_map.len());
         debug!("MirPatch: new_block: {:?}: {:?}", block, data);
         self.new_blocks.push(data);
         self.patch_map.push(None);
         block
     }
 
-    pub fn patch_terminator(&mut self, block: BasicBlock, new: TerminatorKind<'tcx>) {
+    pub(crate) fn patch_terminator(&mut self, block: BasicBlock, new: TerminatorKind<'tcx>) {
         assert!(self.patch_map[block].is_none());
         debug!("MirPatch: patch_terminator({:?}, {:?})", block, new);
         self.patch_map[block] = Some(new);
     }
 
-    pub fn add_statement(&mut self, loc: Location, stmt: StatementKind<'tcx>) {
+    pub(crate) fn add_statement(&mut self, loc: Location, stmt: StatementKind<'tcx>) {
         debug!("MirPatch: add_statement({:?}, {:?})", loc, stmt);
         self.new_statements.push((loc, stmt));
     }
 
-    pub fn add_assign(&mut self, loc: Location, place: Place<'tcx>, rv: Rvalue<'tcx>) {
+    pub(crate) fn add_assign(&mut self, loc: Location, place: Place<'tcx>, rv: Rvalue<'tcx>) {
         self.add_statement(loc, StatementKind::Assign(Box::new((place, rv))));
     }
 
-    pub fn apply(self, body: &mut Body<'tcx>) {
+    pub(crate) fn apply(self, body: &mut Body<'tcx>) {
         debug!(
             "MirPatch: {:?} new temps, starting from index {}: {:?}",
             self.new_locals.len(),
@@ -241,14 +235,14 @@ impl<'tcx> MirPatch<'tcx> {
         }
     }
 
-    pub fn source_info_for_index(data: &BasicBlockData<'_>, loc: Location) -> SourceInfo {
+    fn source_info_for_index(data: &BasicBlockData<'_>, loc: Location) -> SourceInfo {
         match data.statements.get(loc.statement_index) {
             Some(stmt) => stmt.source_info,
             None => data.terminator().source_info,
         }
     }
 
-    pub fn source_info_for_location(&self, body: &Body<'tcx>, loc: Location) -> SourceInfo {
+    pub(crate) fn source_info_for_location(&self, body: &Body<'tcx>, loc: Location) -> SourceInfo {
         let data = match loc.block.index().checked_sub(body.basic_blocks.len()) {
             Some(new) => &self.new_blocks[new],
             None => &body[loc.block],

compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs

@@ -1,10 +1,11 @@
 use rustc_index::bit_set::DenseBitSet;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 use rustc_target::spec::PanicStrategy;
 use tracing::debug;
 
+use crate::patch::MirPatch;
+
 /// A pass that removes noop landing pads and replaces jumps to them with
 /// `UnwindAction::Continue`. This is important because otherwise LLVM generates
 /// terrible code for these.

compiler/rustc_mir_transform/src/shim.rs

@@ -6,7 +6,6 @@ use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_index::{Idx, IndexVec};
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::adjustment::PointerCoercion;
@@ -19,6 +18,7 @@ use rustc_span::{DUMMY_SP, Span};
 use tracing::{debug, instrument};
 
 use crate::elaborate_drop::{DropElaborator, DropFlagMode, DropStyle, Unwind, elaborate_drop};
+use crate::patch::MirPatch;
 use crate::{
     abort_unwinding_calls, add_call_guards, add_moves_for_packed_drops, deref_separator, inline,
     instsimplify, mentioned_items, pass_manager as pm, remove_noop_landing_pads, simplify,

compiler/rustc_mir_transform/src/sroa.rs

@@ -4,13 +4,14 @@ use rustc_hir::LangItem;
 use rustc_index::IndexVec;
 use rustc_index::bit_set::{DenseBitSet, GrowableBitSet};
 use rustc_middle::bug;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_mir_dataflow::value_analysis::{excluded_locals, iter_fields};
 use tracing::{debug, instrument};
 
+use crate::patch::MirPatch;
+
 pub(super) struct ScalarReplacementOfAggregates;
 
 impl<'tcx> crate::MirPass<'tcx> for ScalarReplacementOfAggregates {

compiler/rustc_mir_transform/src/unreachable_enum_branching.rs

@@ -3,7 +3,6 @@
 use rustc_abi::Variants;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::bug;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::{
     BasicBlock, BasicBlockData, BasicBlocks, Body, Local, Operand, Rvalue, StatementKind,
     TerminatorKind,
@@ -12,6 +11,8 @@ use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{Ty, TyCtxt};
 use tracing::trace;
 
+use crate::patch::MirPatch;
+
 pub(super) struct UnreachableEnumBranching;
 
 fn get_discriminant_local(terminator: &TerminatorKind<'_>) -> Option<Local> {

compiler/rustc_mir_transform/src/unreachable_prop.rs

@@ -6,10 +6,11 @@ use rustc_abi::Size;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::bug;
 use rustc_middle::mir::interpret::Scalar;
-use rustc_middle::mir::patch::MirPatch;
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, TyCtxt};
 
+use crate::patch::MirPatch;
+
 pub(super) struct UnreachablePropagation;
 
 impl crate::MirPass<'_> for UnreachablePropagation {