Drop support for legacy PM with LLVM 15
LLVM 15 already removes some of the legacy PM APIs we're using. This patch forces use of NewPM with LLVM 15 (with `-Z new-llvm-pass-manager=no` throwing a warning) and stubs out various FFI methods with a report_fatal_error on LLVM 15.
For LLVMPassManagerBuilderPopulateLTOPassManager() I went with adding our own wrapper, as the alternative would be to muck about with weak symbols, which seems to be non-trivial as far as cross-platform support is concerned (std has `weak!` for this purpose, but only as an internal utility.)
Fixes#96072.
Fixes#96362.
Implement MIR opt unit tests
This implements rust-lang/compiler-team#502 .
There's not much to say here, this implementation does everything as proposed. I also added the flag to a bunch of existing tests (mostly those to which I could add it without causing huge diffs due to changes in line numbers). Summarizing the changes to test outputs:
- Every time an `MirPatch` is created, it adds a cleanup block to the body if it did not exist already. If this block is unused (as is usually the case), it usually gets removed soon after by some pass calling `SimplifyCFG` for unrelated reasons (in many cases this cycle happens quite a few times for a single body). We now run `SimplifyCFG` less often, so those blocks end up in some of our outputs. I looked at changing `MirPatch` to not do this, but that seemed too complicated for this PR. I may still do that in a follow-up.
- The `InstCombine` test had set `-C opt-level=0` in its flags and so there were no storage markers. I don't really see a good motivation for doing this, so bringing it back in line with what everything else does seems correct.
- One of the `EarlyOtherwiseBranch` tests had `UnreachableProp` running on it. Preventing that kind of thing is the goal of this feature, so this seems fine.
For the remaining tests for which this feature might be useful, we can gradually migrate them as opportunities present themselves.
In terms of documentation, I plan on submitting a PR to the rustc dev guide in the near future documenting this and other recent changes to MIR. If there's any other places to update, do let me know
r? `@nagisa`
Improve span for `consider adding an explicit lifetime bound` suggestions under NLL
Because NLL borrowck is run after typeck, `in_progress_typeck_results` was always `None` which was preventing the retrieval of the span to which the suggestion is suppose to add the lifetime bound.
We now manually pass the `LocalDefId` owner to `construct_generic_bound_failure` so that under NLL, we give the owner id of the current body.
This helps with #96332
make `classify_drop_access_kind` iterate
This PR:
1. fixes the FIXME of `classify_drop_access_kind` func in the borrowck part. The process of obtaining `StorageDeadOrDrop` has been changed from recursive to iterative.
2. gets `place_ty` in each iteration, avoid repeatedly getting the `ty` of the same place (O(n^2) => O(n))
Because NLL borrowck is run after typeck, `in_progress_typeck_results`
was always `None` which was preventing the retrieval of the span to which
the suggestion is suppose to add the lifetime bound.
We now manually pass the `LocalDefId` owner to `construct_generic_bound_failure`
so that under NLL, we give the owner id of the current body.
This adds `nounused` to the set of extern flags:
`--extern nounused:core=/path/to/core/libcore.rlib`.
The effect of this flag is to suppress `unused-crate-dependencies`
warnings relating to the crate.
Optimize `const_prop` mir-opt by accessing `local_decls` through `ecx`
From the FIXME in the impl of `ConstPropagator`. Accessing `local_decls` and `scource_scopes` from `ecx` can reduce `clone` calls and save compile time.
Besides, according to #96213 , the FIXME about writing `layouts` to `ecx` in advance can also be removed.
Remove visibility information from HIR
The resolver exports all the necessary visibility information through the `tcx.visibility` query.
This PR stops having a dedicated visibility field in HIR, in order to use this query.
We keep a `vis_span` field for diagnostic purposes.
When suggesting the use of a fully qualified path for a method call that
is ambiguous because it has multiple candidates, erase type params in
the resulting code, as they would result in an error when applied. We
replace them with `_` in the output to rely on inference. There might be
cases where this still produces slighlty incomplete suggestions, but it
otherwise produces many more errors in relatively common cases.
Fix#96292
Sync rustc_codegen_cranelift
Mostly fixing bugs this time, but also a Cranelift update.
r? `@ghost`
`@rustbot` label +A-codegen +A-cranelift +T-compiler
debuginfo: Emit ZST struct debuginfo for unit type when CPP-like debuginfo is enabled
As already discovered in 24a728a8eb, PDB does not play well with custom basic types. This PR extends to the fix to `()`: Instead of a custom basic type, we treat it like an empty tuple (i.e. it is described as a struct which happens to have no fields).
Before this change anything with a `()` in it would cause trouble, which is especially bad for `*const ()` and `*mut ()` which are often used for opaque pointers. E.g. the test case added in this PR would look like:
```
0:000> dx _ref
Error: Unable to bind name '_ref'
0:000> dx _ptr
Error: Unable to bind name '_ptr'
0:000> dx _local
Error: Unable to bind name '_local'
0:000> dx _field,d
_field,d [Type: unit_type::_TypeContainingUnitField]
[+0x008] _a : 123 [Type: unsigned int]
[+0x000] _unit : Unexpected failure to dereference object
[+0x000] _b : 456 [Type: unsigned __int64]
0:000> dx ((__int64 *)_ptr),x
Error: Unable to bind name '_ptr'
```
With the PR it produces the expected output:
```
0:000> dx _ref
_ref : 0x7ff6f2012230 : () [Type: tuple$<> *]
0:000> dx _ptr
_ptr : 0x7e8ddffc20 : () [Type: tuple$<> *]
0:000> dx _local
_local : () [Type: tuple$<>]
0:000> dx _field,d
_field,d [Type: unit_type::_TypeContainingUnitField]
[+0x008] _a : 123 [Type: unsigned int]
[+0x000] _unit : () [Type: tuple$<>]
[+0x000] _b : 456 [Type: unsigned __int64]
0:000> dx ((__int64 *)_ptr),x
((__int64 *)_ptr),x : 0x7e8ddffc20 : 0x1122334455667788 [Type: __int64 *]
```
r? `@wesleywiser`
self-profiler: record spans for proc-macro expansions
This PR is a follow-up to #95473, using the arg recorder feature from #95689:
- it adds support code to easily record spans in the event's arguments, when using `generic_activity_with_arg_recorder`.
- uses that to record the spans where proc-macro expansions happen in addition to their name.
As for the other 2 PRs, the goal here is to provide visibility into proc-macro expansion performance, so that users can diagnose which uses of proc-macros in their code could be causing compile time issues.
Some areas where I'd love feedback:
- [x] the API and names: the `SpannedEventArgRecorder` trait and its method, much like #95689 had the same question about the `EventArgRecorder` naming
- [x] we don't currently have a way to record the names of the event arguments, so should `record_arg_spanned` record the span as "location: {}" or similar ?
Make the lifetime accurate which is used in the region constraints part
This PR fixes the FIXME about lifetime using in the region constraints part.
We cannot write `<'graph, 'tcx, D>` because the definition of `Successors<'0, '1, D>` requires `'1 : '0`.
We cannot add bound to `'graph` either because `'graph` is required to be an arbitrary value in the definition of `WithSuccessors`
So the most accurate way is to use `<'s, 'tcx, D>`.
cc `@Aaron1011` who added this FIXME in #85343
The self-profiler's `EventArgRecorder` is general-purpose in its ability to record Strings (and `rustc_span` depends on the crate its defined in, `rustc_data_structure`).
Some generic activities could use recording locations where they happen in the user's code: to allow e.g. to track macro expansions and diagnose performance issues there.
This adds a `SpannedEventArgRecorder` that can record an argument given as a span, rather than a String, since turning spans into Strings can be tricky if you're not happy with its default Debug output. This way the recorder can have a `record_arg_spanned` method which will do that.
Make all thir types implement clone
This PR adds `Clone` impl to all of the `Thir<'tcx>` types.
I would like to be able to clone a `Thir` body so that I can make a copy in my rustc driver without breaking further compilation. Without this my driver is forced to run in the `after_expansion` callback and thus doesn't benefit from running all the safety checks that `rustc` usually does, instead i need to do them all myself.
