Rework upcasting confirmation to support upcasting to fewer projections in target bounds
This PR implements a modified trait upcasting algorithm that is resilient to changes in the number of associated types in the bounds of the source and target trait objects.
It does this by equating each bound of the target trait ref individually against the bounds of the source trait ref, rather than doing them all together by constructing a new trait object.
#### The new way we do trait upcasting confirmation
1. Equate the target trait object's principal trait ref with one of the supertraits of the source trait object's principal.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2509-L2525)
2. Make sure that every auto trait in the *target* trait object is present in the source trait ref's bounds.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2559-L2562)
3. For each projection in the *target* trait object, make sure there is exactly one projection that equates with it in the source trait ref's bound. If there is more than one, bail with ambiguity.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2526-L2557)
* Since there may be more than one that applies, we probe first to check that there is exactly one, then we equate it outside of a probe once we know that it's unique.
4. Make sure the lifetime of the source trait object outlives the lifetime of the target.
<details>
<summary>Meanwhile, this is how we used to do upcasting:</summary>
1. For each supertrait of the source trait object, take that supertrait, append the source object's projection bounds, and the *target* trait object's auto trait bounds, and make this into a new object type:
d12c6e947c/compiler/rustc_trait_selection/src/traits/select/confirmation.rs (L915-L929)
2. Then equate it with the target trait object:
d12c6e947c/compiler/rustc_trait_selection/src/traits/select/confirmation.rs (L936)
This will be a type mismatch if the target trait object has fewer projection bounds, since we compare the bounds structurally in relate:
d12c6e947c/compiler/rustc_middle/src/ty/relate.rs (L696-L698)
</details>
Fixes#114035
Also fixes#114113, because I added a normalize call in the old solver.
r? types
bootstrap: config: fix version comparison bug
Rust requires a previous version of Rust to build, such as the current version, or the previous version. However, the version comparison logic did not take patch releases into consideration when doing the version comparison for the current branch, e.g. Rust 1.71.1 could not be built by Rust 1.71.0 because it is neither an exact version match, or the previous version.
Adjust the version comparison logic to tolerate mismatches in the patch version.
resolve before canonicalization in new solver, ICE if unresolved
Fold the values with a resolver before canonicalization instead of making it happen within canonicalization.
This allows us to filter trivial region constraints from the external constraints.
r? ``@lcnr``
Perform OpaqueCast field projection on HIR, too.
fixes#105819
This is necessary for closure captures in 2021 edition, as they capture individual fields, not the full mentioned variables. So it may try to capture a field of an opaque (because the hidden type is known to be something with a field).
See https://github.com/rust-lang/rust/pull/99806 for when and why we added OpaqueCast to MIR.
cg_llvm: stop identifying ADTs in LLVM IR
This is an extension of https://github.com/rust-lang/rust/pull/94107. It may be a minor perf win.
Fixes#96242.
Now that we use opaque pointers, ADTs can no longer be recursive, so we
do not need to name them. Previously, this would be necessary if you had
a struct like
```rs
struct Foo(Box<Foo>, u64, u64);
```
which would be represented with something like
```ll
%Foo = type { %Foo*, i64, i64 }
```
which is now just
```ll
{ ptr, i64, i64 }
```
r? `@tmiasko`
Enable tests on rustc_codegen_ssa
This enables unittests in rustc_codegen_ssa. There are some tests, primarily in [`back/rpath/tests.rs`](https://github.com/rust-lang/rust/blob/HEAD/compiler/rustc_codegen_ssa/src/back/rpath/tests.rs) that haven't ever been running since the unittests are disabled. From what I can tell, this was just a consequence of how things evolved. When testing was initially added in https://github.com/rust-lang/rust/pull/33282, `librustc_trans` had test=false because it didn't have any tests. `rustc_codegen_ssa` eventually split off from that (https://github.com/rust-lang/rust/pull/55627), and the rpath module eventually got merged in too (from `librustc_back` where it used to live). That migration didn't enable the tests.
This also includes some fluent diagnostic tests, though I'm not sure what exactly they are testing.
compiletest: Handle non-utf8 paths (fix FIXME)
Removes the last FIXME in the code for #9639🎉 (which was closed 8 years ago)
Part of #44366 which is E-help-wanted.
(The other two PRs that does this are #114377 and #114427)
unix/kernel_copy.rs: copy_file_range_candidate allows empty output files
This is for https://github.com/rust-lang/rust/issues/114341
The `meta.len() > 0` condition here is intended for inputs only, ie. when input is in the `/proc` filesystem as documented.
That inaccurately included empty output files which are then shunted to the sendfile() routine leading to higher than nescessary IO util in some cases, specifically with CoW filesystems like btrfs.
Simply, determine what is input or output given the passed boolean.
Forbid old-style `simd_shuffleN` intrinsics
Don't merge before https://github.com/rust-lang/packed_simd/pull/350 has made its way to crates.io
We used to support specifying the lane length of simd_shuffle ops by attaching the lane length to the name of the intrinsic (like `simd_shuffle16`). After this PR, you cannot do that anymore, and need to instead either rely on inference of the `idx` argument type or specify it as `simd_shuffle::<_, [u32; 16], _>`.
r? `@workingjubilee`
Strip unexpected debuginfo from `libLLVM.so` and `librustc_driver.so` when not requesting any debuginfo
As seen in #114175 and in [this zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/247081-t-compiler.2Fperformance/topic/Artifact.20sizes/near/379302655), there's still some small amount of debuginfo in LLVM's shared library on linux, even when not requesting it (nightly CI), coming from `libstdc++`.
```
$ readelf --debug-dump=info ~/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM-16-rust-1.73.0-nightly.so | grep DW_TAG_compile_unit -A5 | grep DW_AT_comp_dir | cut -d ":" -f 2- | counts
101 counts
( 1) 39 (38.6%, 38.6%): (indirect string, offset: 0x7): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++
( 2) 38 (37.6%, 76.2%): (indirect string, offset: 0x43fb2): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++11
( 3) 23 (22.8%, 99.0%): (indirect string, offset: 0x18ed8): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++98
( 4) 1 ( 1.0%,100.0%): (indirect string, offset: 0x53f04): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src
```
Similarly, here's `librustc_driver.so` when not requesting debuginfo from either rustc or the tools (nightly CI), coming e.g. from our LLVM wrapper:
```
$ readelf --debug-dump=info ~/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e534b3a316089f5f.so | grep DW_TAG_compile_unit -A5 | grep DW_AT_comp_dir | cut -d ":" -f 2- | counts
116 counts
( 1) 34 (29.3%, 29.3%): (indirect string, offset: 0x3c11): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++
( 2) 32 (27.6%, 56.9%): (indirect string, offset: 0x9753c): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++11
( 3) 25 (21.6%, 78.4%): (indirect string, offset: 0x393bd): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++98
( 4) 23 (19.8%, 98.3%): (indirect string, offset: 0x33ed3): /cargo/registry/src/index.crates.io-6f17d22bba15001f/compiler_builtins-0.1.98
( 5) 1 ( 0.9%, 99.1%): (indirect string, offset: 0xaffff): /rustc/0d95f9132909ae7c5f2456748d0ffd1c3ba4a8e8
( 6) 1 ( 0.9%,100.0%): (indirect string, offset: 0xb604a): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src
```
To reduce the size of distributed artifacts, this PR strips debuginfo from the LLVM and `rustc_driver` shared libraries, when:
- no debuginfo is requested when building LLVM: `link-shared` is true, `optimize` is true and `release-debuginfo` is false
- no debuginfo is requested when building the rustc driver:
- `debuginfo-level-rustc` and `debuginfo-level-tools` are off.
- when building with a stage != 0 compiler: since this is about the distributed artifacts, there's no need to do this at other stages.
- for both: on a x64 linux host and target where `strip -g` is available and fixes the issue (I don't know how to strip debuginfo from a `.dylib` on mac). The LLVM BOLTed .so, and `librustc_driver.so` are big there, and this will help a little. Other targets/hosts can be added in the future if we want to.
#114175 did the same thing unconditionally in `opt-dist`, prior to BOLTing LLVM. But this should only be used in conjunction with the other config options mentioned above, and which `opt-dist` doesn't know about. Therefore, it makes more sense as in bootstrap when building LLVM and rustc when applicable and no debuginfo is requested.
This shouldn't interact badly with CI caching builds and artifacts, right?
---
From the other PR, `libLLVM-16-rust-1.73.0-nightly.so` prior to #114141:
- master: 173.13 MiB
- stripped debuginfo: 165.12 MiB (-8 MiB, -4.6%)
`libLLVM-16-rust-1.73.0-nightly.so` after #114141:
- master: 121.13 MiB
- stripped debuginfo: 113.12 MiB (still -8 MiB, -6.6%)
`librustc_driver.so`:
- master: 118.58 MiB
- stripped debuginfo: 106.46 MiB (-12 MiB, -10.2%)
(Results are also available in this most recent [perf run's artifact sizes](https://perf.rust-lang.org/compare.html?start=b321edd1b2d4bd00c7b4611e8f20a03ee7b77023&end=810ab570d5d27facb91806e5d9847815d9dac22a&stat=instructions%3Au&tab=artifact-size))
Only unpack tupled args in inliner if we expect args to be unpacked
`"rust-call"` is a strange function abi. sometimes, it expects the arguments to be unpacked by the caller and passed as individual args (closure bodies), and sometimes it does not (user functions annotated with the `"rust-call"` abi).
make sure the mir inliner respects this difference when checking that arguments are compatible, and doesn't try to ICE when we call a `extern "rust-call"` function in a generic context.
fixes#110829
This is for https://github.com/rust-lang/rust/issues/114341
The `meta.len() > 0` condition here is intended for inputs only,
ie. when input is in the `/proc` filesystem as documented.
That inaccurately included empty output files which are then shunted to
the sendfile() routine leading to higher than nescessary IO util in some
cases, specifically with CoW filesystems like btrfs.
Further, `NoneObtained` is not relevant in this context, so remove it.
Simply, determine what is input or output given the passed enum Unit.
Add `internal_features` lint
Implements https://github.com/rust-lang/compiler-team/issues/596
Also requires some more test blessing for codegen tests etc
`@jyn514` had the idea of just `allow`ing the lint by default in the test suite. I'm not sure whether this is a good idea, but it's definitely one worth considering. Additional input encouraged.
Rust requires a previous version of Rust to build, such as the current version, or the
previous version. However, the version comparison logic did not take patch releases
into consideration when doing the version comparison for the current branch, e.g.
Rust 1.71.1 could not be built by Rust 1.71.0 because it is neither an exact version
match, or the previous version.
Adjust the version comparison logic to tolerate mismatches in the patch version.
Signed-off-by: Ariadne Conill <ariadne@dereferenced.org>
Rollup of 8 pull requests
Successful merges:
- #113657 (Expand, rename and improve `incorrect_fn_null_checks` lint)
- #114237 (parser: more friendly hints for handling `async move` in the 2015 edition)
- #114300 (Suggests turbofish in patterns)
- #114372 (const validation: point at where we found a pointer but expected an integer)
- #114395 ([rustc_span][perf] Hoist lookup sorted by words out of the loop.)
- #114403 (fix the span in the suggestion of remove question mark)
- #114408 (Temporary remove myself from review rotation)
- #114415 (Skip checking of `rustc_codegen_gcc` with vendoring enabled)
r? `@ghost`
`@rustbot` modify labels: rollup
Update cargo (CVE-2023-38497 fix included)
2 commits in 020651c52257052d28f6fd83fbecf5cfa1ed516c..d78bbf4bde3c6b95caca7512f537c6f9721426ff
2023-08-02 16:00:37 +0000 to 2023-08-03 12:58:25 +0000
- Fix CVE-2023-38497 for master (rust-lang/cargo#12443)
- Don't attempt to read a token from stdin if a cmdline token is provided (rust-lang/cargo#12440)
r? `@ghost`
Skip checking of `rustc_codegen_gcc` with vendoring enabled
`rustc_codegen_gcc` currently cannot be vendored, which [breaks](https://github.com/rust-lang/rust/issues/112393) `x.py check` with vendoring enabled. Until the vendoring issue is resolved, it would be nice if `x.py check` could succeed (and just skip `gcc`) with `vendor = true`. With this PR, it does.
Related issue: https://github.com/rust-lang/rust/issues/112393
r? bootstrap
Temporary remove myself from review rotation
I'm going on vacation from 7-th to 15-th and won't be reviewing PRs or writing code.
Feel free to still ping me if you want, I'll read everything when I'm back, but most likely not sooner =)
