Make compiletest output truncation less disruptive
When the test output becomes too large, compiletest stops recording all of it. However:
- this can lead to invalid JSON, which then causes compiletest itself to throw further errors
- the note that output was truncated is in the middle of the output, with >100kb of text on each side; that makes it almost impossible to actually see that note in the terminal
So assuming that we do need to keep the output truncation, I propose that we only ever do a cut at the end, so that it is very clear by looking at the end of the log that truncation happened. I added a message at the beginning of the output as well. Also I added some logic to make it less likely that we'll cut things off in the middle of a JSON record. (I tested that successfully by reducing the output limit to something very low and running a few ui tests.) Furthermore I increased the max buffer size to 512KB; that's really not a lot of memory compared to how much RAM it takes to build rustc (it's ~25% more than the previous maximum HEAD+TAIL length). And finally, the information that things got truncated is now propagated to the higher levels, so that we can fail the test instead of comparing the truncated output with the reference.
Fixes https://github.com/rust-lang/rust/issues/115675
Fixes https://github.com/rust-lang/rust/issues/96229
Fixes https://github.com/rust-lang/rust/issues/94322
Fixes https://github.com/rust-lang/rust/issues/92211
tests: re-enable pretty-std-collections on macOS
Fixes#78665.
I made some small modifications to this test so that it would pass for me locally (though I was only able to test using lldb without built-in Rust support, but that seems to be the mode in which it would fail). I ran it a few hundred times with stage one and stage two to see if I could re-produce the spurious failures that were being reported in #78665 and couldn't. From the discussion in #78665, it seemed like this was related to Xcode versions and could be reproduced locally fairly easily. It's been a couple years since this was disabled so a lot has changed. If this starts failing spuriously again then we can disable it and I can look into that.
r? `@wesleywiser` (discussed in wg-debugging's triage meeting)
Implement some `llvm.x86.sse2.*` intrinsics and add tests
Continuation of https://github.com/rust-lang/miri/pull/2989 with SSE2 intrinsics.
Thankfully, a significant amount of SSE2 functions use `simd_*` intrinsics, which are already implemented in Miri.
Implements LLVM intrisics needed to run most SSE2 functions from `core::arch::x86{,_64}`.
Also adds miri tests for those functions (mostly copied from core_arch tests).
Read from non-scalar constants and statics in dataflow const-prop
DataflowConstProp is designed to handle scalar values. When MIR features an assignment from a non-scalar constant, we need to manually decompose it into the custom state space.
This PR tweaks interpreter callbacks to allow reusing `eval_mir_constant` without having a stack frame to get a span from.
r? `@oli-obk`
cc `@jachris`
test ABI compatibility for some unsized types as well
and test for what `DispatchFromDyn` needs.
Also I ran this on a whole bunch of targets via Miri and added enough `cfg` to make it all work, as documentation for what does and doesn't currently work. (Most of those targets do not have their tests run on CI anyway.)
Here's the shell rune I used for that:
```
for TARGET in x86_64-unknown-linux-gnu x86_64-pc-windows-gnu aarch64-unknown-linux-gnu s390x-unknown-linux-gnu mips64-unknown-linux-gnuabi64 sparc64-unknown-linux-gnu powerpc64-unknown-linux-gnu powerpc64le-unknown-linux-gnu riscv64gc-unknown-linux-gnu loongarch64-unknown-linux-gnu wasm32-unknown-unknown; do
BOOTSTRAP_SKIP_TARGET_SANITY=1 ./x.py run miri --stage 0 --args tests/ui/abi/compatibility.rs --target $TARGET;
done
```
Add `i686-pc-windows-gnullvm` triple
With various fixes that are already present in the code, a fully working i686 target can join other targets in `*-windows-gnullvm` family. Again this will be mostly useful for MSYS2 right now but I plan to open MCP for providing at least prebuilt std for `windows-gnullvm` as the next step which will expand usability of these targets.
Tier 3 policy:
> A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
I pledge to do my best maintaining it, MSYS2 is one of interested consumers. Previously added `gnullvm` triples proved there is not much maintenance required.
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
This triple name is consistent with other targets and was discussed at [`t-compiler/LLVM+mingw-w64 Windows targets`](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/LLVM.2Bmingw-w64.20Windows.20targets)
> Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
I think the explanation in platform support doc is enough to make this aspect clear.
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
It's using open source tools only.
> The target must not introduce license incompatibilities.
It's even more liberal than already existing `*-pc-windows-gnu`.
> Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
Understood.
> The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
There are no new dependencies/features required.
> Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
As previously said it's using open source tools only.
> "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
There are no such terms present.
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
I'm not the reviewer here.
> This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
Again I'm not the reviewer here.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
It seems to work, at least for cross compilation.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
Building is described in platform support doc, running tests doesn't work right now (without hacks) because Rust's build system doesn't seem to support testing targets built from `.json`.
Docs will be updated once this lands in beta allowing master branch to build and run tests without `.json` files.
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
Understood.
> Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
Understood.
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
I believe I didn't break any other target.
> In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
I think there are no such problems in this PR.
interpret: change ABI-compat test to be type-based
This makes the test consistent across targets. Otherwise the chances are very high that ABI mismatches get accepted on x86_64 but still fail on many other targets with more complicated ABIs.
This implements (most of) the rules described in https://github.com/rust-lang/rust/pull/115476.
coverage: Clean up encoding of per-function coverage mapping payloads
This PR contains several small improvements to the code in `rustc_codegen_llvm::coverageinfo::mapgen` that prepares a function's coverage mappings for FFI, and passes them over to LLVM to be encoded into a vector of bytes.
These changes are in preparation for some future changes to the coverage implementation, but they should all stand on their own as worthwhile.
There shouldn't be any changes to the resulting coverage mappings, as verified by the existing `tests/coverage-map` and `tests/run-coverage` suites.
The changes are mostly independent of each other, though they are indirectly affected by the indentation changes made when introducing `GlobalFileTable`.
