Test benchmarks with `-Z panic-abort-tests`
During test execution, when a `#[bench]` benchmark is encountered it's executed once to check whether it works. Unfortunately that was not compatible with `-Z panic-abort-tests`: the feature works by spawning a subprocess for each test, which prevents the use of dynamic tests as we cannot pass closures to child processes, and before this PR the conversion from benchmark to test was done by turning benchmarks into dynamic tests whose closures execute the benchmark once.
The approach this PR took was to add two new kinds of `TestFn`s: `StaticBenchAsTestFn` and `DynBenchAsTestFn` (⚠️ **this is a breaking change** ⚠️). With that change, a `StaticBenchFn` can be converted into a `StaticBenchAsTestFn` without creating dynamic tests, and making it possible to test `#[bench]` functions with `-Z panic-abort-tests`. The subprocess test runner also had to be updated to perform the conversion from benchmark to test when appropriate.
Along with the bug fix, in the first commit I refactored how tests are executed: rather than executing the test function in multiple places across `libtest`, there is now a private `TestFn::into_runnable()` method, which returns either a `RunnableTest` or `RunnableBench`, on which you can call the `run()` method. This simplified the rest of the changes in the PR.
This PR is best reviewed commit-by-commit.
Fixes https://github.com/rust-lang/rust/issues/73509
Before this commit, both static and dynamic benches were converted to a
DynTestFn, with a boxed closure that ran the benchmarks exactly once.
While this worked, it conflicted with -Z panic-abort-tests as the flag
does not support dynamic tests. With this change, a StaticBenchFn is
converted to a StaticBenchAsTestFn, avoiding any dynamic test creation.
DynBenchFn is also converted to DynBenchAsTestFn for completeness.
Before this commit, tests were invoked in multiple places, especially
due to `-Z panic-abort-tests`, and adding a new test kind meant having
to chase down and update all these places.
This commit creates a new Runnable enum, and its children RunnableTest
and RunnableBench. The rest of the harness will now pass around the enum
rather than constructing and passing around boxed functions. The enum
has two children enums because invoking tests and invoking benchmarks
requires different parameters.
Add a `sysroot` crate to represent the standard library crates
This adds a dummy crate named `sysroot` to represent the standard library target instead of using the `test` crate. This allows the removal of `proc_macro` as a dependency of `test` allowing these 2 crates to build in parallel saving around 9 seconds locally.
By placing the stdout in a CDATA block we avoid almost all escaping, as
there's only two byte sequences you can't sneak into a CDATA and you can
handle that with some only slightly regrettable CDATA-splitting. I've
done this in at least two other implementations of the junit xml format
over the years and it's always worked out. The only quirk new to this
(for me) is smuggling newlines as 
 to avoid literal newlines in the
output.
Allow setting CFG_DISABLE_UNSTABLE_FEATURES to 0
Two locations check whether this build-time environment variable is defined. Allowing it to be explicitly disabled with a "0" value is useful, especially for integrating with external build systems.
Two locations check whether this build-time environment variable is
defined. Allowing it to be explicitly disabled with a "0" value is
useful, especially for integrating with external build systems.
- Remove unnecessary references and dereferences
- Use `.contains` instead of `a <= x && x <= b`
- Use `mem::take` instead of `mem::replace` where possible
libtest: run all tests in their own thread, if supported by the host
This reverts the threading changes of https://github.com/rust-lang/rust/pull/56243, which made it so that with `-j1`, the test harness does not spawn any threads. Those changes were done to enable Miri to run the test harness, but Miri supports threads nowadays, so this is no longer needed. Using a thread for each test is useful because the thread's name can be set to the test's name which makes panic messages consistent between `-j1` and `-j2` runs and also a bit more readable.
I did not revert the HashMap changes of https://github.com/rust-lang/rust/pull/56243; using a deterministic map seems fine for the test harness and the more deterministic testing is the better.
Fixes https://github.com/rust-lang/rust/issues/59122
Fixes https://github.com/rust-lang/rust/issues/70492
Sort tests at compile time, not at startup
Recently, another Miri user was trying to run `cargo miri test` on the crate `iced-x86` with `--features=code_asm,mvex`. This configuration has a startup time of ~18 minutes. That's ~18 minutes before any tests even start to run. The fact that this crate has over 26,000 tests and Miri is slow makes a lot of code which is otherwise a bit sloppy but fine into a huge runtime issue.
Sorting the tests when the test harness is created instead of at startup time knocks just under 4 minutes out of those ~18 minutes. I have ways to remove most of the rest of the startup time, but this change requires coordinating changes of both the compiler and libtest, so I'm sending it separately.
(except for doctests, because there is no compile-time harness)
The UNIX and WASI implementations use `isatty`. The Windows
implementation uses the same logic the `atty` crate uses, including the
hack needed to detect msys terminals.
Implement this trait for `File` and for `Stdin`/`Stdout`/`Stderr` and
their locked counterparts on all platforms. On UNIX and WASI, implement
it for `BorrowedFd`/`OwnedFd`. On Windows, implement it for
`BorrowedHandle`/`OwnedHandle`.
Based on https://github.com/rust-lang/rust/pull/91121
Co-authored-by: Matt Wilkinson <mattwilki17@gmail.com>
Do not panic when a test function returns Result::Err.
Rust's test library allows test functions to return a `Result`, so that the test is deemed to have failed if the function returns a `Result::Err` variant. Currently, this works by having `Result` implement the `Termination` trait and asserting in assert_test_result that `Termination::report()` indicates successful completion. This turns a `Result::Err` into a panic, which is caught and unwound in the test library.
This approach is problematic in certain environments where one wishes to save on both binary size and compute resources when running tests by:
* Compiling all code with `--panic=abort` to avoid having to generate unwinding tables, and
* Running most tests in-process to avoid the overhead of spawning new processes.
This change removes the intermediate panic step and passes a `Result::Err` directly through to the test runner.
To do this, it modifies `assert_test_result` to return a `Result<(), String>` where the `Err` variant holds what was previously the panic message. It changes the types in the `TestFn` enum to return `Result<(), String>`.
This tries to minimise the changes to benchmark tests, so it calls `unwrap()` on the `Result` returned by `assert_test_result`, effectively keeping the same behaviour as before.
Some questions for reviewers:
* Does the change to the return types in the enum `TestFn` constitute a breaking change for the library API? Namely, the enum definition is public but the test library indicates that "Currently, not much of this is meant for users" and most of the library API appears to be marked unstable.
* Is there a way to test this change, i.e., to test that no panic occurs if a test returns `Result::Err`?
* Is there a shorter, more idiomatic way to fold `Result<Result<T,E>,E>` into a `Result<T,E>` than the `fold_err` function I added?
Rust's test library allows test functions to return a Result, so that the test is deemed to have failed if the function returns a Result::Err variant. Currently, this works by having Result implement the Termination trait and asserting in assert_test_result that Termination::report() indicates successful completion. This turns a Result::Err into a panic, which is caught and unwound in the test library.
This approach is problematic in certain environments where one wishes to save on both binary size and compute resources when running tests by:
* Compiling all code with --panic=abort to avoid having to generate unwinding tables, and
* Running most tests in-process to avoid the overhead of spawning new processes.
This change removes the intermediate panic step and passes a Result::Err directly through to the test runner.
To do this, it modifies assert_test_result to return a Result<(), String> where the Err variant holds what was previously the panic message. It changes the types in the TestFn enum to return Result<(), String>.
This tries to minimise the changes to benchmark tests, so it calls unwrap() on the Result returned by assert_test_result, effectively keeping the same behaviour as before.
Currently the documentation of f64::min refers to "IEEE-754 2008" while the documentation of
f64::minimum refers to "IEEE 754-2019".
Note that one has the format IEEE,hyphen,number,space,year while the other is
IEEE,space,number,hyphen,year. The official IEEE site [1] uses the later format and it is also the
one most commonly used throughout the codebase.
Update all comments and - more importantly - documentation to consistently use the official format.
[1] https://standards.ieee.org/ieee/754/4211/
Recently, another Miri user was trying to run `cargo miri test` on the
crate `iced-x86` with `--features=code_asm,mvex`. This configuration has
a startup time of ~18 minutes. That's ~18 minutes before any tests even
start to run. The fact that this crate has over 26,000 tests and Miri is
slow makes a lot of code which is otherwise a bit sloppy but fine into a
huge runtime issue.
Sorting the tests when the test harness is created instead of at startup
time knocks just under 4 minutes out of those ~18 minutes. I have ways
to remove most of the rest of the startup time, but this change requires
coordinating changes of both the compiler and libtest, so I'm sending it
separately.
Bump bootstrap compiler to 1.61.0 beta
This PR bumps the bootstrap compiler to the 1.61.0 beta. The first commit changes the stage0 compiler, the second commit applies the "mechanical" changes and the third and fourth commits apply changes explained in the relevant comments.
r? `@Mark-Simulacrum`
Improve terse test output.
The current terse output gives 112 chars per line, which causes
wraparound for people using 100 char wide terminals, which is very
common.
This commit changes it to be exactly 100 wide, which makes the output
look much nicer.
The current terse output gives 112 chars per line, which causes
wraparound for people using 100 char wide terminals, which is very
common.
This commit changes it to be exactly 100 wide, which makes the output
look much nicer.
Stabilize Termination and ExitCode
From https://github.com/rust-lang/rust/issues/43301
This PR stabilizes the Termination trait and associated ExitCode type. It also adjusts the ExitCode feature flag to replace the placeholder flag with a more permanent name, as well as splitting off the `to_i32` method behind its own permanently unstable feature flag.
This PR stabilizes the termination trait with the following signature:
```rust
pub trait Termination {
fn report(self) -> ExitCode;
}
```
The existing impls of `Termination` are effectively already stable due to the prior stabilization of `?` in main.
This PR also stabilizes the following APIs on exit code
```rust
#[derive(Clone, Copy, Debug)]
pub struct ExitCode(_);
impl ExitCode {
pub const SUCCESS: ExitCode;
pub const FAILURE: ExitCode;
}
impl From<u8> for ExitCode { /* ... */ }
```
---
All of the previous blockers have been resolved. The main ones that were resolved recently are:
* The trait's name: We decided against changing this since none of the alternatives seemed particularly compelling. Instead we decided to end the bikeshedding and stick with the current name. ([link to the discussion](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Termination.2FExit.20Status.20Stabilization/near/269793887))
* Issues around platform specific representations: We resolved this issue by changing the return type of `report` from `i32` to the opaque type `ExitCode`. That way we can change the underlying representation without affecting the API, letting us offer full support for platform specific exit code APIs in the future.
* Custom exit codes: We resolved this by adding `From<u8> for ExitCode`. We choose to only support u8 initially because it is the least common denominator between the sets of exit codes supported by our current platforms. In the future we anticipate adding platform specific extension traits to ExitCode for constructors from larger or negative numbers, as needed.
This updates the standard library's documentation to use the new syntax. The
documentation is worthwhile to update as it should be more idiomatic
(particularly for features like this, which are nice for users to get acquainted
with). The general codebase is likely more hassle than benefit to update: it'll
hurt git blame, and generally updates can be done by folks updating the code if
(and when) that makes things more readable with the new format.
A few places in the compiler and library code are updated (mostly just due to
already having been done when this commit was first authored).
As an example:
#[test]
#[ignore = "not yet implemented"]
fn test_ignored() {
...
}
Will now render as:
running 2 tests
test tests::test_ignored ... ignored, not yet implemented
test result: ok. 1 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out; finished in 0.00s
Use `optflag` for `--report-time`
Essentially, what is described here:
https://github.com/rust-lang/rust/issues/64888#issuecomment-1008047228
There is one difference. The comment proposes to add a
`--report-time-color` option. This change instead uses libtest's
existing `--color` option for that purpose.
The crate name is already set in Cargo.toml. The comment says there is
some logic in the compiler that reads #![crate_name] and not
--crate-name, but I can't find it. Removing it seems to work fine.
* Add wasm64 variants for inline assembly along the same lines as wasm32
* Update a few directives in libtest to check for `target_family`
instead of `target_arch`
* Update some rustc codegen and typechecks specialized for wasm32 to
also work for wasm64.
Implement #85440 (Random test ordering)
This PR adds `--shuffle` and `--shuffle-seed` options to `libtest`. The options are similar to the [`-shuffle` option](c894b442d1/src/testing/testing.go (L1482-L1499)) that was recently added to Go.
Here are the relevant parts of the help message:
```
--shuffle Run tests in random order
--shuffle-seed SEED
Run tests in random order; seed the random number
generator with SEED
...
By default, the tests are run in alphabetical order. Use --shuffle or set
RUST_TEST_SHUFFLE to run the tests in random order. Pass the generated
"shuffle seed" to --shuffle-seed (or set RUST_TEST_SHUFFLE_SEED) to run the
tests in the same order again. Note that --shuffle and --shuffle-seed do not
affect whether the tests are run in parallel.
```
Is an RFC needed for this?
Rename `std:🧵:available_conccurrency` to `std:🧵:available_parallelism`
_Tracking issue: https://github.com/rust-lang/rust/issues/74479_
This PR renames `std:🧵:available_conccurrency` to `std:🧵:available_parallelism`.
## Rationale
The API was initially named `std:🧵:hardware_concurrency`, mirroring the [C++ API of the same name](https://en.cppreference.com/w/cpp/thread/thread/hardware_concurrency). We eventually decided to omit any reference to the word "hardware" after [this comment](https://github.com/rust-lang/rust/pull/74480#issuecomment-662045841). And so we ended up with `available_concurrency` instead.
---
For a talk I was preparing this week I was reading through ["Understanding and expressing scalable concurrency" (A. Turon, 2013)](http://aturon.github.io/academic/turon-thesis.pdf), and the following passage stood out to me (emphasis mine):
> __Concurrency is a system-structuring mechanism.__ An interactive system that deals with disparate asynchronous events is naturally structured by division into concurrent threads with disparate responsibilities. Doing so creates a better fit between problem and solution, and can also decrease the average latency of the system by preventing long-running computations from obstructing quicker ones.
> __Parallelism is a resource.__ A given machine provides a certain capacity for parallelism, i.e., a bound on the number of computations it can perform simultaneously. The goal is to maximize throughput by intelligently using this resource. For interactive systems, parallelism can decrease latency as well.
_Chapter 2.1: Concurrency is not Parallelism. Page 30._
---
_"Concurrency is a system-structuring mechanism. Parallelism is a resource."_ — It feels like this accurately captures the way we should be thinking about these APIs. What this API returns is not "the amount of concurrency available to the program" which is a property of the program, and thus even with just a single thread is effectively unbounded. But instead it returns "the amount of _parallelism_ available to the program", which is a resource hard-constrained by the machine's capacity (and can be further restricted by e.g. operating systems).
That's why I'd like to propose we rename this API from `available_concurrency` to `available_parallelism`. This still meets the criteria we previously established of not attempting to define what exactly we mean by "hardware", "threads", and other such words. Instead we only talk about "concurrency" as an abstract resource available to our program.
r? `@joshtriplett`
make junit output more consistent with default format
The default format of libtest includes new-lines between each section to ensure the label output from cargo is on it's own line
<pre><font color="#A1B56C"><b>❯</b></font> <font color="#A1B56C">cargo</font><font color="#D8D8D8"> </font><font color="#A1B56C">test</font>
<font color="#A1B56C"><b> Compiling</b></font> test-test v0.1.0 (/home/jlusby/tmp/test-test)
<font color="#A1B56C"><b> Finished</b></font> test [unoptimized + debuginfo] target(s) in 0.59s
<font color="#A1B56C"><b> Running</b></font> unittests (target/debug/deps/test_test-639f369234319c09)
running 1 test
test tests::it_works ... <font color="#A1B56C">ok</font>
test result: <font color="#A1B56C">ok</font>. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
<font color="#A1B56C"><b> Doc-tests</b></font> test-test
running 0 tests
test result: <font color="#A1B56C">ok</font>. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
</pre>
But when the junit outputter was added to libtest these newlines were omitted, resulting in some "fun" output when run via cargo.
Note the `Doc-tests` text at the end of the first line of xml.
<pre><font color="#A1B56C"><b>❯</b></font> <font color="#A1B56C">cargo</font><font color="#D8D8D8"> </font><font color="#A1B56C">test</font><font color="#D8D8D8"> </font><font color="#A1B56C">--</font><font color="#D8D8D8"> </font><font color="#A1B56C">-Zunstable-options</font><font color="#D8D8D8"> </font><font color="#A1B56C">--format</font><font color="#D8D8D8"> </font><font color="#A1B56C">junit</font>
<font color="#A1B56C"><b> Finished</b></font> test [unoptimized + debuginfo] target(s) in 0.00s
<font color="#A1B56C"><b> Running</b></font> unittests (target/debug/deps/test_test-639f369234319c09)
<?xml version="1.0" encoding="UTF-8"?><testsuites><testsuite name="test" package="test" id="0" errors="0" failures="0" tests="1" skipped="0" ><testcase classname="tests" name="it_works" time="0"/><system-out/><system-err/></testsuite></testsuites><font color="#A1B56C"><b> Doc-tests</b></font> test-test
<?xml version="1.0" encoding="UTF-8"?><testsuites><testsuite name="test" package="test" id="0" errors="0" failures="0" tests="0" skipped="0" ><system-out/><system-err/></testsuite></testsuites>
</pre>
After this PR the junit output includes the same style of newlines as the pretty format
<pre><font color="#A1B56C"><b>❯</b></font> <font color="#A1B56C">cargo</font><font color="#D8D8D8"> </font><font color="#A1B56C">test</font><font color="#D8D8D8"> </font><font color="#A1B56C">--</font><font color="#D8D8D8"> </font><font color="#A1B56C">-Zunstable-options</font><font color="#D8D8D8"> </font><font color="#A1B56C">--format</font><font color="#D8D8D8"> </font><font color="#A1B56C">junit</font>
<font color="#A1B56C"><b> Compiling</b></font> test-test v0.1.0 (/home/jlusby/tmp/test-test)
<font color="#A1B56C"><b> Finished</b></font> test [unoptimized + debuginfo] target(s) in 0.39s
<font color="#A1B56C"><b> Running</b></font> unittests (target/debug/deps/test_test-42c2320bb9450c69)
<?xml version="1.0" encoding="UTF-8"?><testsuites><testsuite name="test" package="test" id="0" errors="0" failures="0" tests="1" skipped="0" ><testcase classname="tests" name="it_works" time="0"/><system-out/><system-err/></testsuite></testsuites>
<font color="#A1B56C"><b> Doc-tests</b></font> test-test
<?xml version="1.0" encoding="UTF-8"?><testsuites><testsuite name="test" package="test" id="0" errors="0" failures="0" tests="0" skipped="0" ><system-out/><system-err/></testsuite></testsuites>
</pre>
Since RFC 3052 soft deprecated the authors field anyway, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information, we should remove it from
crates in this repo.
Show test type during prints
Test output can sometimes be confusing. For example doctest with the no_run argument are displayed the same way than test that are run.
During #83857 I got the feedback that test output can be confusing.
For the moment test output is
```
test $DIR/test-type.rs - f (line 12) ... ignored
test $DIR/test-type.rs - f (line 15) ... ok
test $DIR/test-type.rs - f (line 21) ... ok
test $DIR/test-type.rs - f (line 6) ... ok
```
I propose to change output by indicating the test type as
```
test $DIR/test-type.rs - f (line 12) ... ignored
test $DIR/test-type.rs - f (line 15) - compile ... ok
test $DIR/test-type.rs - f (line 21) - compile fail ... ok
test $DIR/test-type.rs - f (line 6) ... ok
```
by indicating the test type after the test name (and in the case of doctest after the function name and line) and before the "...".
------------
Note: this is a proof of concept, the implementation is probably not optimal as the properties added in `TestDesc` are only use in the display and does not represent actual change of behavior, maybe `TestType::DocTest` could have fields
