Skip to content

Commit

Permalink
Rollup merge of rust-lang#85254 - cjgillot:reveal-mir, r=lcnr
Browse files Browse the repository at this point in the history
Normalize MIR with RevealAll before optimizations.

Fixes rust-lang#78442
  • Loading branch information
matthiaskrgr authored Oct 24, 2021
2 parents a99c9d6 + 70aeced commit 433ecd1
Show file tree
Hide file tree
Showing 7 changed files with 207 additions and 5 deletions.
2 changes: 2 additions & 0 deletions compiler/rustc_mir_transform/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -66,6 +66,7 @@ mod remove_storage_markers;
mod remove_unneeded_drops;
mod remove_zsts;
mod required_consts;
mod reveal_all;
mod separate_const_switch;
mod shim;
mod simplify;
Expand Down Expand Up @@ -490,6 +491,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
// to them. We run some optimizations before that, because they may be harder to do on the state
// machine than on MIR with async primitives.
let optimizations_with_generators: &[&dyn MirPass<'tcx>] = &[
&reveal_all::RevealAll, // has to be done before inlining, since inlined code is in RevealAll mode.
&lower_slice_len::LowerSliceLenCalls, // has to be done before inlining, otherwise actual call will be almost always inlined. Also simple, so can just do first
&normalize_array_len::NormalizeArrayLen, // has to run after `slice::len` lowering
&unreachable_prop::UnreachablePropagation,
Expand Down
2 changes: 1 addition & 1 deletion compiler/rustc_mir_transform/src/remove_unneeded_drops.rs
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ impl<'tcx> MirPass<'tcx> for RemoveUnneededDrops {
trace!("Running RemoveUnneededDrops on {:?}", body.source);

let did = body.source.def_id();
let param_env = tcx.param_env(did);
let param_env = tcx.param_env_reveal_all_normalized(did);
let mut should_simplify = false;

let (basic_blocks, local_decls) = body.basic_blocks_and_local_decls_mut();
Expand Down
58 changes: 58 additions & 0 deletions compiler/rustc_mir_transform/src/reveal_all.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,58 @@
//! Normalizes MIR in RevealAll mode.

use crate::MirPass;
use rustc_middle::mir::visit::*;
use rustc_middle::mir::*;
use rustc_middle::ty::{self, Ty, TyCtxt};

pub struct RevealAll;

impl<'tcx> MirPass<'tcx> for RevealAll {
fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
// This pass must run before inlining, since we insert callee bodies in RevealAll mode.
// Do not apply this transformation to generators.
if (tcx.sess.mir_opt_level() >= 3 || !super::inline::is_enabled(tcx))
&& body.generator.is_none()
{
let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id());
RevealAllVisitor { tcx, param_env }.visit_body(body);
}
}
}

struct RevealAllVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
}

impl<'tcx> MutVisitor<'tcx> for RevealAllVisitor<'tcx> {
#[inline]
fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx
}

#[inline]
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _: TyContext) {
*ty = self.tcx.normalize_erasing_regions(self.param_env, ty);
}

#[inline]
fn process_projection_elem(
&mut self,
elem: PlaceElem<'tcx>,
_: Location,
) -> Option<PlaceElem<'tcx>> {
match elem {
PlaceElem::Field(field, ty) => {
let new_ty = self.tcx.normalize_erasing_regions(self.param_env, ty);
if ty != new_ty { Some(PlaceElem::Field(field, new_ty)) } else { None }
}
// None of those contain a Ty.
PlaceElem::Index(..)
| PlaceElem::Deref
| PlaceElem::ConstantIndex { .. }
| PlaceElem::Subslice { .. }
| PlaceElem::Downcast(..) => None,
}
}
}
8 changes: 4 additions & 4 deletions src/test/mir-opt/inline/inline_generator.main.Inline.diff
Original file line number Diff line number Diff line change
Expand Up @@ -3,10 +3,10 @@

fn main() -> () {
let mut _0: (); // return place in scope 0 at $DIR/inline-generator.rs:8:11: 8:11
let _1: std::ops::GeneratorState<<impl std::ops::Generator<bool> as std::ops::Generator<bool>>::Yield, <impl std::ops::Generator<bool> as std::ops::Generator<bool>>::Return>; // in scope 0 at $DIR/inline-generator.rs:9:9: 9:11
let mut _2: std::pin::Pin<&mut impl std::ops::Generator<bool>>; // in scope 0 at $DIR/inline-generator.rs:9:14: 9:32
let mut _3: &mut impl std::ops::Generator<bool>; // in scope 0 at $DIR/inline-generator.rs:9:23: 9:31
let mut _4: impl std::ops::Generator<bool>; // in scope 0 at $DIR/inline-generator.rs:9:28: 9:31
let _1: std::ops::GeneratorState<i32, bool>; // in scope 0 at $DIR/inline-generator.rs:9:9: 9:11
let mut _2: std::pin::Pin<&mut [generator@$DIR/inline-generator.rs:15:5: 15:41]>; // in scope 0 at $DIR/inline-generator.rs:9:14: 9:32
let mut _3: &mut [generator@$DIR/inline-generator.rs:15:5: 15:41]; // in scope 0 at $DIR/inline-generator.rs:9:23: 9:31
let mut _4: [generator@$DIR/inline-generator.rs:15:5: 15:41]; // in scope 0 at $DIR/inline-generator.rs:9:28: 9:31
+ let mut _7: bool; // in scope 0 at $DIR/inline-generator.rs:9:14: 9:46
scope 1 {
debug _r => _1; // in scope 1 at $DIR/inline-generator.rs:9:9: 9:11
Expand Down
20 changes: 20 additions & 0 deletions src/test/mir-opt/inline/issue-78442.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
// compile-flags: -Z mir-opt-level=3 -Z inline-mir
// ignore-wasm32-bare compiled with panic=abort by default
#![crate_type = "lib"]

// EMIT_MIR issue_78442.bar.RevealAll.diff
// EMIT_MIR issue_78442.bar.Inline.diff
pub fn bar<P>(
// Error won't happen if "bar" is not generic
_baz: P,
) {
hide_foo()();
}

fn hide_foo() -> impl Fn() {
// Error won't happen if "iterate" hasn't impl Trait or has generics
foo
}

fn foo() { // Error won't happen if "foo" isn't used in "iterate" or has generics
}
67 changes: 67 additions & 0 deletions src/test/mir-opt/inline/issue_78442.bar.Inline.diff
Original file line number Diff line number Diff line change
@@ -0,0 +1,67 @@
- // MIR for `bar` before Inline
+ // MIR for `bar` after Inline

fn bar(_1: P) -> () {
debug _baz => _1; // in scope 0 at $DIR/issue-78442.rs:9:5: 9:9
let mut _0: (); // return place in scope 0 at $DIR/issue-78442.rs:10:3: 10:3
let _2: (); // in scope 0 at $DIR/issue-78442.rs:11:5: 11:17
let mut _3: &fn() {foo}; // in scope 0 at $DIR/issue-78442.rs:11:5: 11:15
let _4: fn() {foo}; // in scope 0 at $DIR/issue-78442.rs:11:5: 11:15
let mut _5: (); // in scope 0 at $DIR/issue-78442.rs:11:5: 11:17
+ scope 1 (inlined <fn() {foo} as Fn<()>>::call - shim(fn() {foo})) { // at $DIR/issue-78442.rs:11:5: 11:17
+ }

bb0: {
StorageLive(_2); // scope 0 at $DIR/issue-78442.rs:11:5: 11:17
StorageLive(_3); // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
StorageLive(_4); // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
- _4 = hide_foo() -> [return: bb1, unwind: bb4]; // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
+ _4 = hide_foo() -> [return: bb1, unwind: bb3]; // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
// mir::Constant
// + span: $DIR/issue-78442.rs:11:5: 11:13
// + literal: Const { ty: fn() -> impl std::ops::Fn<()> {hide_foo}, val: Value(Scalar(<ZST>)) }
}

bb1: {
_3 = &_4; // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
StorageLive(_5); // scope 0 at $DIR/issue-78442.rs:11:5: 11:17
- _2 = <impl Fn<()> as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb4]; // scope 0 at $DIR/issue-78442.rs:11:5: 11:17
- // mir::Constant
- // + span: $DIR/issue-78442.rs:11:5: 11:15
- // + literal: Const { ty: for<'r> extern "rust-call" fn(&'r impl std::ops::Fn<()>, ()) -> <impl std::ops::Fn<()> as std::ops::FnOnce<()>>::Output {<impl std::ops::Fn<()> as std::ops::Fn<()>>::call}, val: Value(Scalar(<ZST>)) }
+ _2 = move (*_3)() -> [return: bb5, unwind: bb3]; // scope 1 at $DIR/issue-78442.rs:11:5: 11:17
}

bb2: {
- StorageDead(_5); // scope 0 at $DIR/issue-78442.rs:11:16: 11:17
- StorageDead(_3); // scope 0 at $DIR/issue-78442.rs:11:16: 11:17
- StorageDead(_4); // scope 0 at $DIR/issue-78442.rs:11:17: 11:18
- StorageDead(_2); // scope 0 at $DIR/issue-78442.rs:11:17: 11:18
- _0 = const (); // scope 0 at $DIR/issue-78442.rs:10:3: 12:2
- drop(_1) -> [return: bb3, unwind: bb5]; // scope 0 at $DIR/issue-78442.rs:12:1: 12:2
+ return; // scope 0 at $DIR/issue-78442.rs:12:2: 12:2
}

- bb3: {
- return; // scope 0 at $DIR/issue-78442.rs:12:2: 12:2
+ bb3 (cleanup): {
+ drop(_1) -> bb4; // scope 0 at $DIR/issue-78442.rs:12:1: 12:2
}

bb4 (cleanup): {
- drop(_1) -> bb5; // scope 0 at $DIR/issue-78442.rs:12:1: 12:2
+ resume; // scope 0 at $DIR/issue-78442.rs:7:1: 12:2
}

- bb5 (cleanup): {
- resume; // scope 0 at $DIR/issue-78442.rs:7:1: 12:2
+ bb5: {
+ StorageDead(_5); // scope 0 at $DIR/issue-78442.rs:11:16: 11:17
+ StorageDead(_3); // scope 0 at $DIR/issue-78442.rs:11:16: 11:17
+ StorageDead(_4); // scope 0 at $DIR/issue-78442.rs:11:17: 11:18
+ StorageDead(_2); // scope 0 at $DIR/issue-78442.rs:11:17: 11:18
+ _0 = const (); // scope 0 at $DIR/issue-78442.rs:10:3: 12:2
+ drop(_1) -> [return: bb2, unwind: bb4]; // scope 0 at $DIR/issue-78442.rs:12:1: 12:2
}
}

55 changes: 55 additions & 0 deletions src/test/mir-opt/inline/issue_78442.bar.RevealAll.diff
Original file line number Diff line number Diff line change
@@ -0,0 +1,55 @@
- // MIR for `bar` before RevealAll
+ // MIR for `bar` after RevealAll

fn bar(_1: P) -> () {
debug _baz => _1; // in scope 0 at $DIR/issue-78442.rs:9:5: 9:9
let mut _0: (); // return place in scope 0 at $DIR/issue-78442.rs:10:3: 10:3
let _2: (); // in scope 0 at $DIR/issue-78442.rs:11:5: 11:17
- let mut _3: &impl std::ops::Fn<()>; // in scope 0 at $DIR/issue-78442.rs:11:5: 11:15
- let _4: impl std::ops::Fn<()>; // in scope 0 at $DIR/issue-78442.rs:11:5: 11:15
+ let mut _3: &fn() {foo}; // in scope 0 at $DIR/issue-78442.rs:11:5: 11:15
+ let _4: fn() {foo}; // in scope 0 at $DIR/issue-78442.rs:11:5: 11:15
let mut _5: (); // in scope 0 at $DIR/issue-78442.rs:11:5: 11:17

bb0: {
StorageLive(_2); // scope 0 at $DIR/issue-78442.rs:11:5: 11:17
StorageLive(_3); // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
StorageLive(_4); // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
_4 = hide_foo() -> [return: bb1, unwind: bb4]; // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
// mir::Constant
// + span: $DIR/issue-78442.rs:11:5: 11:13
// + literal: Const { ty: fn() -> impl std::ops::Fn<()> {hide_foo}, val: Value(Scalar(<ZST>)) }
}

bb1: {
_3 = &_4; // scope 0 at $DIR/issue-78442.rs:11:5: 11:15
StorageLive(_5); // scope 0 at $DIR/issue-78442.rs:11:5: 11:17
nop; // scope 0 at $DIR/issue-78442.rs:11:5: 11:17
_2 = <impl Fn<()> as Fn<()>>::call(move _3, move _5) -> [return: bb2, unwind: bb4]; // scope 0 at $DIR/issue-78442.rs:11:5: 11:17
// mir::Constant
// + span: $DIR/issue-78442.rs:11:5: 11:15
// + literal: Const { ty: for<'r> extern "rust-call" fn(&'r impl std::ops::Fn<()>, ()) -> <impl std::ops::Fn<()> as std::ops::FnOnce<()>>::Output {<impl std::ops::Fn<()> as std::ops::Fn<()>>::call}, val: Value(Scalar(<ZST>)) }
}

bb2: {
StorageDead(_5); // scope 0 at $DIR/issue-78442.rs:11:16: 11:17
StorageDead(_3); // scope 0 at $DIR/issue-78442.rs:11:16: 11:17
StorageDead(_4); // scope 0 at $DIR/issue-78442.rs:11:17: 11:18
StorageDead(_2); // scope 0 at $DIR/issue-78442.rs:11:17: 11:18
_0 = const (); // scope 0 at $DIR/issue-78442.rs:10:3: 12:2
drop(_1) -> [return: bb3, unwind: bb5]; // scope 0 at $DIR/issue-78442.rs:12:1: 12:2
}

bb3: {
return; // scope 0 at $DIR/issue-78442.rs:12:2: 12:2
}

bb4 (cleanup): {
drop(_1) -> bb5; // scope 0 at $DIR/issue-78442.rs:12:1: 12:2
}

bb5 (cleanup): {
resume; // scope 0 at $DIR/issue-78442.rs:7:1: 12:2
}
}

0 comments on commit 433ecd1

Please sign in to comment.