coverage: Merge refined spans in a separate final pass
Pulling this merge step out of `push_refined_span` and into a separate pass lets us push directly to `refined_spans` instead of calling a helper method.
Because the compiler can now see partial borrows of `refined_spans`, we can remove some extra code that was jumping through hoops to satisfy the borrow checker.
---
``@rustbot`` label +A-code-coverage
Tell MirUsedCollector that the pointer alignment checks calls its panic symbol
Fixes https://github.com/rust-lang/rust/pull/118683 (not an issue, but that PR is a basically a bug report)
When we had `panic_immediate_abort` start adding `#[inline]` to this panic function, builds started breaking because we failed to write up the MIR assert terminator to the correct panic shim. Things happened to work before by pure luck because without this feature enabled, the function we're inserting calls to is `#[inline(never)]` so we always generated code for it.
r? bjorn3
coverage: Avoid unnecessary macros in unit tests
These macros don't provide enough value to justify their complexity, when they can just as easily be functions instead.
---
`@rustbot` label +A-code-coverage
OnceLock: Add note about drop and statics
Hi! Just a minor documentation addition, I've attempted to build docs locally but ran in to issues, so am not 100% sure this change will render correctly.
Elaborate on ip_addr bit conversion endianness
Adds explanation of how endianness is handled when converting `Ipv4Addr` and `Ipv6Addr` to and from bits. This is intended to unblock stabilization of the affected methods.
Addresses #113744
The instance evaluation is needed to handle intrinsics such as
`type_id` and `type_name`.
Since we now use Allocation to represent all evaluated constants,
provide a few methods to help process the data inside an allocation.
`GenKillAnalysis` has five methods that take a transfer function arg:
- `statement_effect`
- `before_statement_effect`
- `terminator_effect`
- `before_terminator_effect`
- `call_return_effect`
All the transfer function args have type `&mut impl GenKill<Self::Idx>`,
except for `terminator_effect`, which takes the simpler `Self::Domain`.
But only the first two need to be `impl GenKill`. The other
three can all be `Self::Domain`, just like `Analysis`. So this commit
changes the last two to take `Self::Domain`, making `GenKillAnalysis`
and `Analysis` more similar.
(Another idea would be to make all these methods `impl GenKill`. But
that doesn't work: `MaybeInitializedPlaces::terminator_effect` requires
the arg be `Self::Domain` so that `self_is_unwind_dead(place, state)`
can be called on it.)
This results in two non-generic types being used: `BorrowckResults` and
`BorrowckFlowState`. It's a net reduction in lines of code, and a little
easier to read.
Rollup of 6 pull requests
Successful merges:
- #116420 (discard invalid spans in external blocks)
- #118686 (Only check principal trait ref for object safety)
- #118688 (Add method to get type of an Rvalue in StableMIR)
- #118707 (Ping GuillaumeGomez for changes in rustc_codegen_gcc)
- #118712 (targets: remove not-added {i386,i486}-unknown-linux-gnu)
- #118719 (CFI: Add char to CFI integer normalization)
Failed merges:
- #117586 (Uplift the (new solver) canonicalizer into `rustc_next_trait_solver`)
r? `@ghost`
`@rustbot` modify labels: rollup
It is used just once. With it removed, the relevant code is a little
boilerplate-y but much easier to read, and is the same length. Overall I
think it's an improvement.
targets: remove not-added {i386,i486}-unknown-linux-gnu
These files were added to the repository but never wired up so they could be used - and that was a few years ago without anyone noticing - so let's remove these, they can be re-added if someone wants them.
cc #80662
r? ```@pnkfelix``` (familiar with the tier policy and Wesley is on vacation)
Ping GuillaumeGomez for changes in rustc_codegen_gcc
Since I work on it and also added its testsuite into rustc's CI, I'd like to know if there are changes.
Add method to get type of an Rvalue in StableMIR
Provide a method to StableMIR users to retrieve the type of an Rvalue operation. There were two possible implementation:
1. Create the logic inside stable_mir to process the type according to the Rvalue semantics, which duplicates the logic of `rustc_middle::mir::Rvalue::ty()`.
2. Implement the Rvalue translation from StableMIR back to internal representation, invoke the `rustc_middle::mir::Rvalue::ty()`, and translate the return value to StableMIR.
I chose the first one for now since the duplication was fairly small, and the option 2 would require way more work to translate everything back to rustc internal representation. If we eventually add those translations, we could easily swap to the option 2.
```@compiler-errors``` / ```@ouz-a``` Please let me know if you have any strong opinion here.
r? ```@compiler-errors```
Only check principal trait ref for object safety
It should make things a bit faster, in case we end up registering a bunch of object safety preds.
r? ```@ghost```
discard invalid spans in external blocks
Fixes#116203
This PR has discarded the invalid `const_span`, thereby making the format more neat.
r? ``@Nilstrieb``
Avoid adding builtin functions to `symbols.o`
We found performance regressions in #113923. The problem seems to be that `--gc-sections` does not remove these symbols. I tested that lld removes these symbols, but ld and gold do not.
I found that `used` adds symbols to `symbols.o` at 3e202ead60/compiler/rustc_codegen_ssa/src/back/linker.rs (L1786-L1791).
The PR removes builtin functions.
Note that under LTO, ld still preserves these symbols. (lld will still remove them.)
The first commit also fixes#118559. But I think the second commit also makes sense.
compile-time evaluation: detect writes through immutable pointers
This has two motivations:
- it unblocks https://github.com/rust-lang/rust/pull/116745 (and therefore takes a big step towards `const_mut_refs` stabilization), because we can now detect if the memory that we find in `const` can be interned as "immutable"
- it would detect the UB that was uncovered in https://github.com/rust-lang/rust/pull/117905, which was caused by accidental stabilization of `copy` functions in `const` that can only be called with UB
When UB is detected, we emit a future-compat warn-by-default lint. This is not a breaking change, so completely in line with [the const-UB RFC](https://rust-lang.github.io/rfcs/3016-const-ub.html), meaning we don't need t-lang FCP here. I made the lint immediately show up for dependencies since it is nearly impossible to even trigger this lint without `const_mut_refs` -- the accidentally stabilized `copy` functions are the only way this can happen, so the crates that popped up in #117905 are the only causes of such UB (in the code that crater covers), and the three cases of UB that we know about have all been fixed in their respective crates already.
The way this is implemented is by making use of the fact that our interpreter is already generic over the notion of provenance. For CTFE we now use the new `CtfeProvenance` type which is conceptually an `AllocId` plus a boolean `immutable` flag (but packed for a more efficient representation). This means we can mark a pointer as immutable when it is created as a shared reference. The flag will be propagated to all pointers derived from this one. We can then check the immutable flag on each write to reject writes through immutable pointers.
I just hope perf works out.
Fix `rustc_codegen_gcc` build and tests failure in CI
https://github.com/rust-lang/rust/pull/118463 seems to have broke the PR CI, more specificaly the `x86_64-gnu-llvm-16` builder which [fail with](https://github.com/rust-lang/rust/actions/runs/7128709674/job/19411205695?pr=118705#step:26:1668):
```
Building stage1 codegen backend gcc (x86_64-unknown-linux-gnu)
Compiling libc v0.2.147
Compiling rustix v0.38.8
Compiling memchr v2.5.0
Compiling bitflags v2.4.0
Compiling linux-raw-sys v0.4.5
Compiling fastrand v2.0.0
Compiling smallvec v1.10.0
error: invalid `--check-cfg` argument: `values(freebsd10)` (expected `cfg(name, values("value1", "value2", ... "valueN"))`)
error: could not compile `libc` (lib) due to previous error
```
Updating to `libc` version 0.2.150 fixes the build issue since it includes the support for the new check-cfg syntax.
Then it [failed](https://github.com/rust-lang/rust/actions/runs/7129280743/job/19413025132?pr=118706#step:26:2218) with a missing `#![allow(internal_features)]` in one of the example.
r? `@GuillaumeGomez`
These files were added to the repository but never wired up so they could
be used - and that was a few years ago without anyone noticing - so let's
remove these, they can be re-added if someone wants them.
Signed-off-by: David Wood <david@davidtw.co>
