Add some track_caller info to precondition panics by saethlin · Pull Request #129658 · rust-lang/rust (original) (raw)
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Currently, when you encounter a precondition check, you'll always get the caller location of the implementation of the precondition checks. But with this PR, you'll be told the location of the invalid call. Which is useful.
I thought of this while looking at #129642 (comment).
The changes to tests/ui/const* happen because the const-eval interpreter skips #[track_caller] frames in its backtraces.
The perf implications of this are:
- Increased debug binary sizes. The caller_location implementation requires that the additional data we want to display here be stored in const allocations, which are deduplicated but not across crates. There is no impact on optimized build sizes. The panic path and the caller location data get optimized out.
- The compile time hit to opt-incr-patched bitmaps happens because the patch changes the line number of some function calls with precondition checks, causing us to go from 0 dirty CGUs to 1 dirty CGU.
- The other compile time hits are marginal but real, and due to doing a handful of new queries. Adding more useful data isn't completely free.
Status: Awaiting review from the assignee but also interested parties.
Relevant to the compiler team, which will review and decide on the PR/issue.
Relevant to the library team, which will review and decide on the PR/issue.
labels
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bors added a commit to rust-lang-ci/rust that referenced this pull request
☀️ Try build successful - checks-actions
Build commit: 7798f9b (7798f9b35d0cd727f26631c015620e3dfe62e1f6)
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Finished benchmarking commit (7798f9b): comparison URL.
Overall result: no relevant changes - no action needed
Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.
@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression
Instruction count
This benchmark run did not return any relevant results for this metric.
Max RSS (memory usage)
Results (secondary -2.7%)
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) | - | - | 0 |
| Regressions ❌ (secondary) | - | - | 0 |
| Improvements ✅ (primary) | - | - | 0 |
| Improvements ✅ (secondary) | -2.7% | [-3.1%, -2.3%] | 2 |
| All ❌✅ (primary) | - | - | 0 |
Cycles
This benchmark run did not return any relevant results for this metric.
Binary size
Results (primary 0.1%, secondary 0.1%)
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) | 0.1% | [0.0%, 0.6%] | 47 |
| Regressions ❌ (secondary) | 0.1% | [0.0%, 0.4%] | 35 |
| Improvements ✅ (primary) | - | - | 0 |
| Improvements ✅ (secondary) | - | - | 0 |
| All ❌✅ (primary) | 0.1% | [0.0%, 0.6%] | 47 |
Bootstrap: 749.925s -> 752.783s (0.38%)
Artifact size: 338.74 MiB -> 338.79 MiB (0.02%)
That looks possibly acceptable. Let's just see how bad this becomes?
@bors try @rust-timer queue
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bors added a commit to rust-lang-ci/rust that referenced this pull request
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☀️ Try build successful - checks-actions
Build commit: 0e77a71 (0e77a71199b6b2f7fac064cdf0b55e84d7ccca61)
This comment has been minimized.
Finished benchmarking commit (0e77a71): comparison URL.
Overall result: ❌✅ regressions and improvements - ACTION NEEDED
Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.
Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.
@bors rollup=never
@rustbot label: -S-waiting-on-perf +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) | 0.2% | [0.2%, 0.2%] | 1 |
| Regressions ❌ (secondary) | - | - | 0 |
| Improvements ✅ (primary) | - | - | 0 |
| Improvements ✅ (secondary) | -0.3% | [-0.3%, -0.3%] | 6 |
| All ❌✅ (primary) | 0.2% | [0.2%, 0.2%] | 1 |
Max RSS (memory usage)
This benchmark run did not return any relevant results for this metric.
Cycles
This benchmark run did not return any relevant results for this metric.
Binary size
Results (primary 0.3%, secondary 0.1%)
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) | 0.3% | [0.0%, 1.4%] | 65 |
| Regressions ❌ (secondary) | 0.1% | [0.0%, 0.5%] | 35 |
| Improvements ✅ (primary) | - | - | 0 |
| Improvements ✅ (secondary) | - | - | 0 |
| All ❌✅ (primary) | 0.3% | [0.0%, 1.4%] | 65 |
Bootstrap: 749.925s -> 751.312s (0.18%)
Artifact size: 338.74 MiB -> 338.81 MiB (0.02%)
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Status: Waiting on bors to run and complete tests. Bors will change the label on completion.
label
bors added a commit that referenced this pull request
Add some track_caller info to precondition panics
Currently, when you encounter a precondition check, you'll always get the caller location of the implementation of the precondition checks. But with this PR, you'll be told the location of the invalid call. Which is useful.
I thought of this while looking at #129642 (comment).
The changes to tests/ui/const* happen because the const-eval interpreter skips #[track_caller] frames in its backtraces.
The perf implications of this are:
- Increased debug binary sizes. The caller_location implementation requires that the additional data we want to display here be stored in const allocations, which are deduplicated but not across crates. There is no impact on optimized build sizes. The panic path and the caller location data get optimized out.
- The compile time hit to opt-incr-patched bitmaps happens because the patch changes the line number of some function calls with precondition checks, causing us to go from 0 dirty CGUs to 1 dirty CGU.
- The other compile time hits are marginal but real, and due to doing a handful of new queries. Adding more useful data isn't completely free.
This comment has been minimized.
Status: Awaiting review from the assignee but also interested parties.
and removed S-waiting-on-bors
Status: Waiting on bors to run and complete tests. Bors will change the label on completion.
labels
This comment has been minimized.
bors added a commit that referenced this pull request
Add some track_caller info to precondition panics
Currently, when you encounter a precondition check, you'll always get the caller location of the implementation of the precondition checks. But with this PR, you'll be told the location of the invalid call. Which is useful.
I thought of this while looking at #129642 (comment).
The changes to tests/ui/const* happen because the const-eval interpreter skips #[track_caller] frames in its backtraces.
The perf implications of this are:
- Increased debug binary sizes. The caller_location implementation requires that the additional data we want to display here be stored in const allocations, which are deduplicated but not across crates. There is no impact on optimized build sizes. The panic path and the caller location data get optimized out.
- The compile time hit to opt-incr-patched bitmaps happens because the patch changes the line number of some function calls with precondition checks, causing us to go from 0 dirty CGUs to 1 dirty CGU.
- The other compile time hits are marginal but real, and due to doing a handful of new queries. Adding more useful data isn't completely free.
try-job: test-various
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
☀️ Try build successful - checks-actions
Build commit: 1cd73d5 (1cd73d518b9babf013044d90e9d757a210a41214)
📌 Commit 6d0e04d has been approved by jhpratt
It is now in the queue for this repository.
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
What is this?This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.
Comparing 45f256d (parent) -> be42293 (this PR)
Test differences
Show 2448 test diffs
2448 doctest diffs were found. These are ignored, as they are noisy.
Test dashboard
Run
cargo run --manifest-path src/ci/citool/Cargo.toml --
test-dashboard be422939446d7c5b27ba98debb6b4b8d6a261f1a --output-dir test-dashboard
And then open test-dashboard/index.html in your browser to see an overview of all executed tests.
Job duration changes
- aarch64-gnu: 6386.1s -> 8098.2s (26.8%)
- aarch64-gnu-debug: 4005.6s -> 4950.7s (23.6%)
- dist-aarch64-apple: 6589.2s -> 5537.3s (-16.0%)
- dist-apple-various: 8252.1s -> 7289.1s (-11.7%)
- x86_64-mingw-2: 7027.3s -> 7622.8s (8.5%)
- dist-i686-mingw: 8764.8s -> 8117.7s (-7.4%)
- x86_64-msvc-ext1: 7718.6s -> 7204.1s (-6.7%)
- x86_64-apple-2: 5063.5s -> 4730.0s (-6.6%)
- dist-x86_64-mingw: 7534.3s -> 7967.5s (5.7%)
- x86_64-gnu-llvm-20-2: 5942.4s -> 6279.6s (5.7%) How to interpret the job duration changes?
Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.
Finished benchmarking commit (be42293): comparison URL.
Overall result: ❌ regressions - please read the text below
Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.
Next Steps:
- If the regression was expected or you think it can be justified,
please write a comment with sufficient written justification, and add@rustbot label: +perf-regression-triagedto it, to mark the regression as triaged. - If you think that you know of a way to resolve the regression, try to create
a new PR with a fix for the regression. - If you do not understand the regression or you think that it is just noise,
you can ask the@rust-lang/wg-compiler-performanceworking group for help (members of this group
were already notified of this PR).
@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance
Instruction count
This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.
| mean | range | count | |
|---|---|---|---|
| Regressions ❌ (primary) | 1.0% | [0.1%, 6.2%] | 14 |
| Regressions ❌ (secondary) | 0.8% | [0.4%, 1.2%] | 4 |
| Improvements ✅ (primary) | -0.5% | [-0.5%, -0.5%] | 1 |
| Improvements ✅ (secondary) | - | - | 0 |
| All ❌✅ (primary) | 0.9% | [-0.5%, 6.2%] | 15 |
Max RSS (memory usage)
Results (primary 1.0%, secondary 3.6%)
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) | 2.9% | [0.9%, 6.7%] | 6 |
| Regressions ❌ (secondary) | 3.6% | [2.2%, 5.1%] | 2 |
| Improvements ✅ (primary) | -4.7% | [-5.7%, -3.7%] | 2 |
| Improvements ✅ (secondary) | - | - | 0 |
| All ❌✅ (primary) | 1.0% | [-5.7%, 6.7%] | 8 |
Cycles
Results (primary 5.7%)
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) | 5.7% | [3.3%, 8.2%] | 2 |
| Regressions ❌ (secondary) | - | - | 0 |
| Improvements ✅ (primary) | - | - | 0 |
| Improvements ✅ (secondary) | - | - | 0 |
| All ❌✅ (primary) | 5.7% | [3.3%, 8.2%] | 2 |
Binary size
Results (primary 0.6%, secondary 1.3%)
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) | 0.6% | [0.0%, 2.8%] | 66 |
| Regressions ❌ (secondary) | 1.3% | [0.1%, 2.9%] | 25 |
| Improvements ✅ (primary) | - | - | 0 |
| Improvements ✅ (secondary) | - | - | 0 |
| All ❌✅ (primary) | 0.6% | [0.0%, 2.8%] | 66 |
Bootstrap: 779.523s -> 779.377s (-0.02%)
Artifact size: 366.37 MiB -> 366.47 MiB (0.03%)
github-actions bot pushed a commit to model-checking/verify-rust-std that referenced this pull request
Add some track_caller info to precondition panics
Currently, when you encounter a precondition check, you'll always get the caller location of the implementation of the precondition checks. But with this PR, you'll be told the location of the invalid call. Which is useful.
I thought of this while looking at rust-lang#129642 (comment).
The changes to tests/ui/const* happen because the const-eval interpreter skips #[track_caller] frames in its backtraces.
The perf implications of this are:
- Increased debug binary sizes. The caller_location implementation requires that the additional data we want to display here be stored in const allocations, which are deduplicated but not across crates. There is no impact on optimized build sizes. The panic path and the caller location data get optimized out.
- The compile time hit to opt-incr-patched bitmaps happens because the patch changes the line number of some function calls with precondition checks, causing us to go from 0 dirty CGUs to 1 dirty CGU.
- The other compile time hits are marginal but real, and due to doing a handful of new queries. Adding more useful data isn't completely free.
Comment on lines -68 to +72
| ::core::panicking::panic_nounwind(concat!("unsafe precondition(s) violated: ", $message, |
|---|
| let msg = concat!("unsafe precondition(s) violated: ", $message, |
| "\n\nThis indicates a bug in the program. \ |
| This Undefined Behavior check is optional, and cannot be relied on for safety.")); |
| This Undefined Behavior check is optional, and cannot be relied on for safety."); |
| ::core::panicking::panic_nounwind_fmt(::core::fmt::Arguments::new_const(&[msg]), false); |
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This might be a slight (unoptimized?) codegen regression, for things as simple as (godbolt):
#[unsafe(no_mangle)] pub fn r_next(mut r: std::ops::Range) -> Option { r.next() }
Before:
@alloc_3e1ebac14318b612ab4efabc52799932 = private unnamed_addr constant [186 x i8] c"unsafe precondition(s) violated: usize::unchecked_add cannot overflow\0A\0AThis indicates a bug in the program. This Undefined Behavior check is optional, and cannot be relied on for safety.", align 1
; ::unchecked_add::precondition_check define internal void @_RNvNvMs9_NtCs1p5UDGgVI4d_4core3numj13unchecked_add18precondition_checkCsb8r2Xq4BFYL_7example(i64 %lhs, i64 %rhs) unnamed_addr #0 { ; … (elided) … bb1: ; preds = %start ; call core::panicking::panic_nounwind call void @_ZN4core9panicking14panic_nounwind17h0c59dc9f7f043eadE(ptr align 1 @alloc_3e1ebac14318b612ab4efabc52799932, i64 186) #6
After:
@alloc_3e1ebac14318b612ab4efabc52799932 = private unnamed_addr constant [186 x i8] c"unsafe precondition(s) violated: usize::unchecked_add cannot overflow\0A\0AThis indicates a bug in the program. This Undefined Behavior check is optional, and cannot be relied on for safety.", align 1 ; … (elided) …
; ::unchecked_add::precondition_check ; Function Attrs: inlinehint nounwind nonlazybind uwtable define internal void @_RNvNvMs9_NtCs25W7cjsTkyH_4core3numj13unchecked_add18precondition_checkCsgRHkggJuglA_7example(i64 %lhs, i64 %rhs, ptr align 8 %0) unnamed_addr #0 { ; … (elided) … bb1: ; preds = %start %2 = getelementptr inbounds nuw { ptr, i64 }, ptr %_6, i64 0 store ptr @alloc_3e1ebac14318b612ab4efabc52799932, ptr %2, align 8 ; … (elided) … ; call core::panicking::panic_nounwind_fmt call void @_ZN4core9panicking18panic_nounwind_fmt17h42ee446b0f35d307E(ptr align 8 %_4, i1 zeroext false, ptr align 8 %0) #6
Notably, even if we ignore the extra IR needed to implement fmt::Arguments::new_const, the fact that &[msg] is pointing to a stack array (as opposed to e.g. const { &[concat!(...)] }) results in the constant string being stored on the stack at runtime.
(and unlike even &[concat!(...)], the let msg blocks even incidental promotion)
That all aside, I am a bit surprised there isn't "just" a copy of panic_nounwind that has #[track_caller], to avoid invoking panic_nounwind_fmt and have this extra codegen (assuming it matters at all, ofc, I just noticed this in passing for unrelated reasons).
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@saethlin , pinging so you can see this
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(To be clear, this is not that important or any kind of a blocker, I just found it slightly notable that runtime code is being unnecessarily generated, and arguably by mistake, even)
