improve diagnostics for tests with custom return values
This is an attempt at getting the ball rolling to improve the diagnostics for test functions that return custom `impl Termination` values (see #52436).
An alternative could be to use `eprintln!`, but including this in the panic message felt nicely consistent with how failing test assertions would be reported.
Let me know what you think!
Don't format!() string literals
Prefer `to_string()` to `format!()` take 2, this time targetting string literals. In some cases (`&format!("...")` -> `"..."`) also removes allocations. Occurences of `format!("")` are changed to `String::new()`.
libtest: Split HumanFormatter into {Pretty,Terse}
libtest: Fixed padding of benchmarks when not benchmarking
libtest: Fixed benchmarks' names not showing in terse-mode
libtest: Formatting
libtest: Json format now outputs failed tests' stdouts.
libtest: Json format now outputs failed tests' stdouts.
libtest: Json formatter now spews individiual events, not as an array
libtest: JSON fixes
libtest: Better JSON escaping
libtest: Test start event is printed on time
CloudABI doesn't make any distinction between TTYs and ordinary pipes.
While there, remove the redundant implementation used by Redox. It can
use the same stub function.
Tiny fixes to make compiletest work for CloudABI cross builds
I'm currently working toward getting a `src/ci/docker` container working to do isolated/automated builds and testing of `x86_64-unknown-cloudabi`. This is working pretty well, but still requires some fixes to `libtest` and `compiletest`. Here is the first set of fixes that I had to apply.
This structure doesn't seem to be used by libtest itself. It is used by
compiletest, but never passed on to anything externally. This makes it
easier to get the testing framework to work for CloudABI crossbuilds, as
CloudABI currently lacks PathBuf, which is used by TestPaths.
This commit adds a new target to the compiler: wasm32-unknown-unknown. This
target is a reimagining of what it looks like to generate WebAssembly code from
Rust. Instead of using Emscripten which can bring with it a weighty runtime this
instead is a target which uses only the LLVM backend for WebAssembly and a
"custom linker" for now which will hopefully one day be direct calls to lld.
Notable features of this target include:
* There is zero runtime footprint. The target assumes nothing exists other than
the wasm32 instruction set.
* There is zero toolchain footprint beyond adding the target. No custom linker
is needed, rustc contains everything.
* Very small wasm modules can be generated directly from Rust code using this
target.
* Most of the standard library is stubbed out to return an error, but anything
related to allocation works (aka `HashMap`, `Vec`, etc).
* Naturally, any `#[no_std]` crate should be 100% compatible with this new
target.
This target is currently somewhat janky due to how linking works. The "linking"
is currently unconditional whole program LTO (aka LLVM is being used as a
linker). Naturally that means compiling programs is pretty slow! Eventually
though this target should have a linker.
This target is also intended to be quite experimental. I'm hoping that this can
act as a catalyst for further experimentation in Rust with WebAssembly. Breaking
changes are very likely to land to this target, so it's not recommended to rely
on it in any critical capacity yet. We'll let you know when it's "production
ready".
---
Currently testing-wise this target is looking pretty good but isn't complete.
I've got almost the entire `run-pass` test suite working with this target (lots
of tests ignored, but many passing as well). The `core` test suite is still
getting LLVM bugs fixed to get that working and will take some time. Relatively
simple programs all seem to work though!
---
It's worth nothing that you may not immediately see the "smallest possible wasm
module" for the input you feed to rustc. For various reasons it's very difficult
to get rid of the final "bloat" in vanilla rustc (again, a real linker should
fix all this). For now what you'll have to do is:
cargo install --git https://github.com/alexcrichton/wasm-gc
wasm-gc foo.wasm bar.wasm
And then `bar.wasm` should be the smallest we can get it!
---
In any case for now I'd love feedback on this, particularly on the various
integration points if you've got better ideas of how to approach them!
Rationale:
We use --quiet mode when testing a PR in the CI. Also, we use `stamp` to
prefix every line with a timestamp. Previously, when testing in --quiet
mode, we will only print a dot for each test without any line breaks.
Combined with `stamp`, this means we'd need to wait for all tests to
complete before writing the output. On Travis CI, if we don't print
anything within 30 minutes, the job will be forcefully canceled. This
makes it very easy to spuriously-timeout when testing non-default images
like arm-android using the CI. This commit tries to workaround the issue
by printing a new line every 100 dots, forcing `stamp` to emit something
to reset Travis's countdown.
