Support tail calls in mir via `TerminatorKind::TailCall` #113128

WaffleLapkin · 2023-06-28T17:02:34Z

This is one of the interesting bits in tail call implementation — MIR support.

This adds a new TerminatorKind which represents a tail call:

    TailCall {
        func: Operand<'tcx>,
        args: Vec<Operand<'tcx>>,
        fn_span: Span,
    },

Structurally this is very similar to a normal Call but is missing a few fields:

destination — tail calls don't write to destination, instead they pass caller's destination to the callee (such that eventual return will write to the caller of the function that used tail call)
target — similarly to destination tail calls pass the caller's return address to the callee, so there is nothing to do
unwind — I think this is applicable too, although it's a bit confusing
call_source — become forbids operators and is not created as a lowering of something else; tail calls always come from HIR (at least for now)

It might be helpful to read the interpreter implementation to understand what TailCall means exactly, although I've tried documenting it too.

There are a few FIXME-questions still left, ideally we'd be able to answer them during review ':)

r? @oli-obk
cc @scottmcm @drmeepster @JakobDegen

rustbot · 2023-06-28T17:02:42Z

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

This PR changes Stable MIR

cc @oli-obk, @celinval

This PR changes MIR

cc @oli-obk, @RalfJung, @JakobDegen, @davidtwco, @celinval, @vakaras

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

matthewjasper · 2023-06-28T20:07:09Z

compiler/rustc_mir_build/src/build/scope.rs

+                        let target = self.cfg.start_new_block();
+                        let terminator = TerminatorKind::Drop {
+                            target,
+                            // The caller will handle this if needed.


I don't think this is true here (looking at the MIR opt tests)

I think actually the inner loop should be replaced with build_scope_drops. That should handle the unwinds correctly and reduce code duplication.

I've picked @drmeepster's fix commit (beepster4096@f79affd) as af3f2f8.

@matthewjasper does the code look correct now?

compiler/rustc_borrowck/src/lib.rs

oli-obk · 2023-06-29T14:32:51Z

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -129,6 +129,8 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
        ccx: &'mir ConstCx<'mir, 'tcx>,
        tainted_by_errors: Option<ErrorGuaranteed>,
    ) -> ConstQualifs {
+        // FIXME(explicit_tail_calls): uhhhh I think we can return without return now, does it change anything


Afaict we don't run mir_const_qualif on const fn anymore (we should change it to assert that instead of silently returning the Default for functions and actually running on const fn were it called for them), so you'd only encounter this situation in constants. 😆 do you have tests for const FOO: u32 = 42; const BAR: u32 = become FOO;?

I don't have a test for it, yet, will add.

To be clear, the following makes an error like "become outside of function body" (similarly to how return) works:

const FOO: u32 = 42; const BAR: u32 = become FOO;

And this ICEs in this PR, but will produce "become requires a function call" once we have the checks (I'll make a PR with them soon in parallel with this one):

const FOO: u32 = 42; fn bar() -> u32 { become FOO; }

oli-obk · 2023-06-29T14:34:57Z

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -695,7 +697,14 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
        self.super_terminator(terminator, location);

        match &terminator.kind {
-            TerminatorKind::Call { func, args, fn_span, call_source, .. } => {
+            TerminatorKind::Call { func, args, fn_span, .. }
+            | TerminatorKind::TailCall { func, args, fn_span, .. } => {


Same situation as above, is this even reachable?

compiler/rustc_const_eval/src/transform/validate.rs

compiler/rustc_middle/src/mir/syntax.rs

compiler/rustc_mir_build/src/lints.rs

oli-obk · 2023-06-29T14:42:53Z

compiler/rustc_mir_dataflow/src/value_analysis.rs

@@ -258,6 +258,9 @@ pub trait ValueAnalysis<'tcx> {
                // They would have an effect, but are not allowed in this phase.
                bug!("encountered disallowed terminator");
            }
+            TerminatorKind::TailCall { .. } => {
+                // FIXME(explicit_tail_calls): determine if we need to do something here (probably not)


oof, we'll need to investigate the users of handle_call_return to see how to best handle these, but I presume we'll want to treat it similar to a return.

compiler/rustc_mir_transform/src/const_prop.rs

compiler/rustc_mir_transform/src/inline.rs

compiler/rustc_const_eval/src/interpret/terminator.rs

nbdd0121 · 2023-06-29T16:45:52Z

unwind — I think this is applicable too, although it's a bit confusing

I feel this is a fast track to UB, unless we have MIR validations to ensure become unwindable_function() in non-unwindable function is prohibited.

It might make more sense to have an unwind field but limited to UnwindAction::Continue and UnwindAction::Unreachable?

WaffleLapkin · 2023-06-30T16:39:43Z

@nbdd0121 but the thing is: tail call can't actually do anything about unwinding since it replaces the current function with the callee. See the interpreter impl where unwind is copied from the current stack frame. I'm not sure what effect could TailCall::unwind have, although I'm probably missing something.

oli-obk · 2023-06-30T16:48:16Z

I think we need to guarantee at the tail call site, that no things with a destructor are still in scope.

nbdd0121 · 2023-06-30T16:51:26Z

If we have nounwind_fn() is the previous frame, then the MIR will be call nounwind_fn() -> [return ..., unwind unreachable], which means the unwind in the code you pointed to will be UnwindAction::Unreachable. If the replacing stack frame can actually unwind, then we can run into UB.

We will need to have checks somewhere to prevent this from happening.

WaffleLapkin · 2023-06-30T17:03:48Z

@oli-obk this is trivially guaranteed by the drop order (drops are run before the tail call), or did I misunderstood your question?

WaffleLapkin · 2023-06-30T17:10:03Z

@nbdd0121 right, I see. When can we generate call nounwind_fn() -> [return ..., unwind unreachable]? I.e. where should we account for the fact that tail calls can potentially unwind?

I'll try adding a mir validator check, but it will only allow us to catch problems, not prevent them.

nbdd0121 · 2023-06-30T17:47:33Z

When can we generate call nounwind_fn() -> [return ..., unwind unreachable]? I.e. where should we account for the fact that tail calls can potentially unwind?

The unwindability is part of the function's ABI or codegen attr that is computed by fn_can_unwind function (this couldn't be changed).

To account for this I think we need to prevent a no-unwind function from tail calling an unwindable function. That is, we have to reject:

fn bar() {}

#[rustc_nounwind]
fn foo() {
    become bar();
}

and

// When compiled with `-C panic=abort`

extern "C-unwind" {
    fn bar();
}

extern "C-unwind" unsafe fn foo() {
    become bar();
}

RalfJung · 2023-07-01T09:28:36Z

The interpreter also needs to be able to catch potential UB here (and we should probably have a Miri test), e.g. when a nounwind function becomes a function pointer and unsafe shenanigans were used to make the function called via that pointer actually unwind.

bors · 2023-07-02T18:43:57Z

☔ The latest upstream changes (presumably #113260) made this pull request unmergeable. Please resolve the merge conflicts.

RalfJung · 2023-07-07T13:20:44Z

compiler/rustc_const_eval/src/interpret/terminator.rs

+                // Note that we can't use `pop_stack_frame` as it "executes"
+                // the goto to the return block, but we don't want to,
+                // only the tail called function should return to the current
+                // return block.


pop_stack_frame does a bunch of other stuff as well though that seems relevant, such as calling after_stack_pop.

What if the old function has return type bool, but the callee has return type u8 and returns 2 -- is that UB? I would think so but currently I think that would be missed. (Even if the static checks ensure this can't usually happen, we can always transmute a fn() -> bool to fn() -> u8 to circumvent those checks.)

pop_stack_frame does a bunch of other stuff as well though that seems relevant, such as calling after_stack_pop.

In particular this is relevant for the aliasing model, where protectors are active until the stack frame pops.

This is actually an interesting question for the aliasing model... should protector remain active until before or after the tail call?

What if the old function has return type bool, but the callee has return type u8 and returns 2 -- is that UB? I would think so but currently I think that would be missed.

I haven't tested it yet, but I actually think this won't be missed, because the check is in the eval_fn_call:

rust/compiler/rustc_const_eval/src/interpret/terminator.rs

Lines 578 to 587 in af3f2f8

// Don't forget to check the return type!

if !Self::check_argument_compat(&caller_fn_abi.ret, &callee_fn_abi.ret) {

let callee_ty = format!("{}", callee_fn_abi.ret.layout.ty);

let caller_ty = format!("{}", caller_fn_abi.ret.layout.ty);

throw_ub_custom!(

fluent::const_eval_incompatible_return_types,

callee_ty = callee_ty,

caller_ty = caller_ty,

)

}

But pop_stack_frame indeed does a lot more (like deallocating locals). @RalfJung what do you think would be the best to implement necessary things for tail calls here? Just copy all the necessary bits into eval_terminator (in the TailCall arm)? Should we try sharing similar bits between pop_stack_frame and tail calls (that potentially seems annoying...)? Should we introduce a new hook (M::before_tail_call) (should it default to M::after_stack_pop?)?

In particular this is relevant for the aliasing model, where protectors are active until the stack frame pops.

This is actually an interesting question for the aliasing model... should protector remain active until before or after the tail call?

This is indeed an interesting question... I'd assume protectors remain active until before the tail call, since we basically replace the current stack frame with a new one.

I haven't tested it yet, but I actually think this won't be missed, because the check is in the eval_fn_call:

That check will treat bool and u8 as being compatible, so it won't catch this problem.

Given that the caller basically delegates its return place to the callee, I think it would be reasonable to say that the caller's type no longer matters. However this means we cannot easily turn a tail call into a regular call as the validity requirements may change then.

I'd assume protectors remain active until before the tail call, since we basically replace the current stack frame with a new one.

This depends on whether we allow the compiler to turn tail calls into regular calls, assuming it can know that this won't lead to exploding stack usage.

I'm okay with punting on the aliasing question for now, we should just make sure to track it somewhere.

More interesting is the unwinding question. If a nounwind function tailcalls to a mayunwind function, and then unwinds, that must still be UB. However that might already be taken care of? The new stack frame will inherit the return_to_block info from the old one, in particular the unwind action, so if that says Unreachable we'll still trigger UB as desired. I assume a tail call itself doesn't have an unwind action, it just gets inherited from the current stack frame?

what do you think would be the best to implement necessary things for tail calls here? Just copy all the necessary bits into eval_terminator (in the TailCall arm)? Should we try sharing similar bits between pop_stack_frame and tail calls (that potentially seems annoying...)? Should we introduce a new hook (M::before_tail_call) (should it default to M::after_stack_pop?)?

I think we want a replace_stack_frame function in eval_context.rs right besides push/pop_stack_frame, so all this code is reasonably close to each other. (Maybe we should move all this to a new stack.rs file or so.) And if there are significant parts that are shared with push_stack_frame and pop_stack_frame, that should probably move into helper functions.

Given that the caller basically delegates its return place to the callee, I think it would be reasonable to say that the caller's type no longer matters. However this means we cannot easily turn a tail call into a regular call as the validity requirements may change then.

By "caller's type no longer matters" do you mean that in this scenario c is sound? (b definitely isn't though)

fn a() -> u8 { 2 } fn b() -> bool { become transmute::<fn() -> u8, fn() -> bool>(a)(); } fn c() { let _x: u8 = transmute::<fn() -> bool, fn() -> u8>(b)(); }

I'm okay with punting on the aliasing question for now, we should just make sure to track it somewhere.

Can you open an issue to track this?

More interesting is the unwinding question. If a nounwind function tailcalls to a mayunwind function, and then unwinds, that must still be UB. However that might already be taken care of? The new stack frame will inherit the return_to_block info from the old one, in particular the unwind action, so if that says Unreachable we'll still trigger UB as desired. I assume a tail call itself doesn't have an unwind action, it just gets inherited from the current stack frame?

Yes, this sounds correct to me.

I think we want a replace_stack_frame function in eval_context.rs right besides push/pop_stack_frame, so all this code is reasonably close to each other. (Maybe we should move all this to a new stack.rs file or so.) And if there are significant parts that are shared with push_stack_frame and pop_stack_frame, that should probably move into helper functions.

Ok. I will look into implementing this

Opened an issue: rust-lang/unsafe-code-guidelines#491.

RalfJung · 2023-07-07T13:21:28Z

compiler/rustc_const_eval/src/interpret/terminator.rs

+                    &prev_frame.return_place,
+                    ret,
+                    unwind,
+                )?;


Please add tests in src/tools/miri/tests to ensure tail calls work in Miri. You can run those tests with ./x.py test miri --stage 0.

Well, the test shows that tail calls in fact don't work in miri 😅

Tail calls trip this assertion:

rust/src/tools/miri/src/concurrency/thread.rs

Line 186 in 8d361cb

debug_assert_eq!(self.top_user_relevant_frame, self.compute_top_user_relevant_frame());

I guess this is to be expected since we do not call after_stack_pop which maintains this cache...

bors · 2023-07-12T12:17:30Z

☔ The latest upstream changes (presumably #113569) made this pull request unmergeable. Please resolve the merge conflicts.

Dylan-DPC · 2023-08-18T06:08:07Z

@WaffleLapkin any updates on this? thanks

WaffleLapkin · 2023-08-22T16:38:34Z

@Dylan-DPC the labels are accurate: this is waiting on me resolving conflicts and addressing review comments.

src/tools/miri/tests/fail/tail_calls/signature-mismatch-arg.rs

WaffleLapkin · 2024-07-07T20:06:39Z

@bors r=oli-obk,RalfJung

WaffleLapkin · 2024-07-07T20:07:45Z

@bors r=oli-obk,RalfJung

bors · 2024-07-07T20:07:47Z

📌 Commit 14e5d5f has been approved by oli-obk,RalfJung

It is now in the queue for this repository.

…le, r=oli-obk,RalfJung Support tail calls in mir via `TerminatorKind::TailCall` This is one of the interesting bits in tail call implementation — MIR support. This adds a new `TerminatorKind` which represents a tail call: ```rust TailCall { func: Operand<'tcx>, args: Vec<Operand<'tcx>>, fn_span: Span, }, ``` *Structurally* this is very similar to a normal `Call` but is missing a few fields: - `destination` — tail calls don't write to destination, instead they pass caller's destination to the callee (such that eventual `return` will write to the caller of the function that used tail call) - `target` — similarly to `destination` tail calls pass the caller's return address to the callee, so there is nothing to do - `unwind` — I _think_ this is applicable too, although it's a bit confusing - `call_source` — `become` forbids operators and is not created as a lowering of something else; tail calls always come from HIR (at least for now) It might be helpful to read the interpreter implementation to understand what `TailCall` means exactly, although I've tried documenting it too. ----- There are a few `FIXME`-questions still left, ideally we'd be able to answer them during review ':) ----- r? `@oli-obk` cc `@scottmcm` `@DrMeepster` `@JakobDegen`

Rollup of 12 pull requests Successful merges: - rust-lang#113128 (Support tail calls in mir via `TerminatorKind::TailCall`) - rust-lang#126841 ([`macro_metavar_expr_concat`] Add support for literals) - rust-lang#126881 (Make `NEVER_TYPE_FALLBACK_FLOWING_INTO_UNSAFE` a deny-by-default lint in edition 2024) - rust-lang#126921 (Give VaList its own home) - rust-lang#127276 (rustdoc: Remove OpaqueTy) - rust-lang#127367 (Run alloc sync tests) - rust-lang#127431 (Use field ident spans directly instead of the full field span in diagnostics on local fields) - rust-lang#127437 (Uplift trait ref is knowable into `rustc_next_trait_solver`) - rust-lang#127439 (Uplift elaboration into `rustc_type_ir`) - rust-lang#127451 (Improve `run-make/output-type-permutations` code and improve `filename_not_in_denylist` API) - rust-lang#127452 (Fix intrinsic const parameter counting with `effects`) - rust-lang#127459 (rustdoc-json: add type/trait alias tests) r? `@ghost` `@rustbot` modify labels: rollup

bors · 2024-07-08T04:35:07Z

⌛ Testing commit 14e5d5f with merge 9af6fee...

bors · 2024-07-08T06:46:04Z

☀️ Test successful - checks-actions
Approved by: oli-obk,RalfJung
Pushing 9af6fee to master...

rust-timer · 2024-07-08T08:03:46Z

Finished benchmarking commit (9af6fee): comparison URL.

Overall result: ❌✅ regressions and improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.3%	[0.2%, 0.3%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

Results (primary 2.2%, secondary 8.8%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.2%	[0.8%, 3.8%]	7
Regressions ❌ (secondary)	10.0%	[5.3%, 15.1%]	10
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.7%	[-2.7%, -2.7%]	1
All ❌✅ (primary)	2.2%	[0.8%, 3.8%]	7

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 700.046s -> 699.651s (-0.06%)
Artifact size: 328.35 MiB -> 328.40 MiB (0.02%)

…, r=oli-obk,RalfJung Support tail calls in mir via `TerminatorKind::TailCall` This is one of the interesting bits in tail call implementation — MIR support. This adds a new `TerminatorKind` which represents a tail call: ```rust TailCall { func: Operand<'tcx>, args: Vec<Operand<'tcx>>, fn_span: Span, }, ``` *Structurally* this is very similar to a normal `Call` but is missing a few fields: - `destination` — tail calls don't write to destination, instead they pass caller's destination to the callee (such that eventual `return` will write to the caller of the function that used tail call) - `target` — similarly to `destination` tail calls pass the caller's return address to the callee, so there is nothing to do - `unwind` — I _think_ this is applicable too, although it's a bit confusing - `call_source` — `become` forbids operators and is not created as a lowering of something else; tail calls always come from HIR (at least for now) It might be helpful to read the interpreter implementation to understand what `TailCall` means exactly, although I've tried documenting it too. ----- There are a few `FIXME`-questions still left, ideally we'd be able to answer them during review ':) ----- r? `@oli-obk` cc `@scottmcm` `@DrMeepster` `@JakobDegen`

compiler/rustc_borrowck/src/lib.rs

… r=workingjubilee Revert accidental comment deletion This reverts an accidental comment deletion made in rust-lang#113128 See also rust-lang#113128 (comment)

Rollup merge of rust-lang#127625 - SkiFire13:revert-comment-deletion, r=workingjubilee Revert accidental comment deletion This reverts an accidental comment deletion made in rust-lang#113128 See also rust-lang#113128 (comment)

…, r=oli-obk,RalfJung Support tail calls in mir via `TerminatorKind::TailCall` This is one of the interesting bits in tail call implementation — MIR support. This adds a new `TerminatorKind` which represents a tail call: ```rust TailCall { func: Operand<'tcx>, args: Vec<Operand<'tcx>>, fn_span: Span, }, ``` *Structurally* this is very similar to a normal `Call` but is missing a few fields: - `destination` — tail calls don't write to destination, instead they pass caller's destination to the callee (such that eventual `return` will write to the caller of the function that used tail call) - `target` — similarly to `destination` tail calls pass the caller's return address to the callee, so there is nothing to do - `unwind` — I _think_ this is applicable too, although it's a bit confusing - `call_source` — `become` forbids operators and is not created as a lowering of something else; tail calls always come from HIR (at least for now) It might be helpful to read the interpreter implementation to understand what `TailCall` means exactly, although I've tried documenting it too. ----- There are a few `FIXME`-questions still left, ideally we'd be able to answer them during review ':) ----- r? `@oli-obk` cc `@scottmcm` `@DrMeepster` `@JakobDegen`

WaffleLapkin added the F-explicit_tail_calls `#![feature(explicit_tail_calls)]` label Jun 28, 2023

rustbot assigned oli-obk Jun 28, 2023

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jun 28, 2023

This comment has been minimized.

Sign in to view

rust-cloud-vms bot force-pushed the become_trully_unuwuable branch from 574d9a5 to 7ba9e99 Compare June 28, 2023 17:22

WaffleLapkin mentioned this pull request Jun 28, 2023

Tracking Issue for Explicit Tail Calls #112788

Open

6 tasks

matthewjasper reviewed Jun 28, 2023

View reviewed changes

oli-obk reviewed Jun 29, 2023

View reviewed changes

RalfJung reviewed Jul 7, 2023

View reviewed changes

RalfJung mentioned this pull request Jul 7, 2023

Can we require bounded stack consumption? rust-lang/unsafe-code-guidelines#427

Open

WaffleLapkin added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 10, 2023

rust-cloud-vms bot force-pushed the become_trully_unuwuable branch from 119cb0d to 406bd6b Compare July 11, 2023 18:04

WaffleLapkin mentioned this pull request Nov 26, 2023

feature: Add basic support for become expr/tail calls rust-lang/rust-analyzer#15003

Merged

tranquillity-codes removed the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label Jan 15, 2024

WaffleLapkin force-pushed the become_trully_unuwuable branch from 2b9d091 to 7fd0c55 Compare July 7, 2024 16:16

RalfJung reviewed Jul 7, 2024

View reviewed changes

src/tools/miri/tests/fail/tail_calls/signature-mismatch-arg.rs Outdated Show resolved Hide resolved

This comment has been minimized.

Sign in to view

WaffleLapkin added 2 commits July 7, 2024 20:16

Fixup conflict with r-l/r/126567

39eaefc

Fixup a typo in a comment in a test

14e5d5f

WaffleLapkin closed this Jul 7, 2024

WaffleLapkin reopened this Jul 7, 2024

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Jul 7, 2024

jieyouxu mentioned this pull request Jul 8, 2024

Rollup of 12 pull requests #127475

Closed

bors added the merged-by-bors This PR was explicitly merged by bors. label Jul 8, 2024

bors merged commit 9af6fee into rust-lang:master Jul 8, 2024
13 checks passed

rustbot added this to the 1.81.0 milestone Jul 8, 2024

WaffleLapkin deleted the become_trully_unuwuable branch July 8, 2024 08:19

GrigorenkoPV mentioned this pull request Jul 10, 2024

ICE. thir_check_tail_calls should have disallowed this Expr #127530

Closed

SkiFire13 reviewed Jul 11, 2024

View reviewed changes

compiler/rustc_borrowck/src/lib.rs Show resolved Hide resolved

SkiFire13 mentioned this pull request Jul 11, 2024

Revert accidental comment deletion #127625

Merged

RalfJung mentioned this pull request Aug 5, 2024

interpret: refactor function call handling to be better-abstracted #128687

Merged

	// Don't forget to check the return type!
	if !Self::check_argument_compat(&caller_fn_abi.ret, &callee_fn_abi.ret) {
	let callee_ty = format!("{}", callee_fn_abi.ret.layout.ty);
	let caller_ty = format!("{}", caller_fn_abi.ret.layout.ty);
	throw_ub_custom!(
	fluent::const_eval_incompatible_return_types,
	callee_ty = callee_ty,
	caller_ty = caller_ty,
	)
	}

Support tail calls in mir via TerminatorKind::TailCall #113128

Support tail calls in mir via TerminatorKind::TailCall #113128

Conversation

WaffleLapkin commented Jun 28, 2023

rustbot commented Jun 28, 2023

This comment has been minimized.

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

nbdd0121 commented Jun 29, 2023

WaffleLapkin commented Jun 30, 2023

oli-obk commented Jun 30, 2023

nbdd0121 commented Jun 30, 2023

WaffleLapkin commented Jun 30, 2023

WaffleLapkin commented Jun 30, 2023

nbdd0121 commented Jun 30, 2023

RalfJung commented Jul 1, 2023 • edited Loading

bors commented Jul 2, 2023

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

RalfJung Aug 7, 2023 • edited Loading

Choose a reason for hiding this comment

WaffleLapkin Feb 15, 2024 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

bors commented Jul 12, 2023

Dylan-DPC commented Aug 18, 2023

WaffleLapkin commented Aug 22, 2023

This comment has been minimized.

WaffleLapkin commented Jul 7, 2024

WaffleLapkin commented Jul 7, 2024

bors commented Jul 7, 2024

bors commented Jul 8, 2024

bors commented Jul 8, 2024

rust-timer commented Jul 8, 2024

Overall result: ❌✅ regressions and improvements - no action needed

Support tail calls in mir via `TerminatorKind::TailCall` #113128

Support tail calls in mir via `TerminatorKind::TailCall` #113128

RalfJung commented Jul 1, 2023 •

edited

Loading

RalfJung Aug 7, 2023 •

edited

Loading

WaffleLapkin Feb 15, 2024 •

edited

Loading