Ban custom inner attributes in expressions and statements
Split out from https://github.com/rust-lang/rust/pull/82608
Custom inner attributes are unstable, so this won't break any stable users.
This allows us to speed up token collection, and avoid a redundant call to `collect_tokens_no_attrs` when parsing an `Expr` that has outer attributes.
r? `@petrochenkov`
Import small cold functions
The Rust code is often written under an assumption that for generic
methods inline attribute is mostly unnecessary, since for optimized
builds using ThinLTO, a method will be code generated in at least one
CGU and available for import.
For example, deref implementations for Box, Vec, MutexGuard, and
MutexGuard are not currently marked as inline, neither is identity
implementation of From trait.
In PGO builds, when functions are determined to be cold, the default
multiplier of zero will stop the import, no matter how trivial the
implementation.
Increase slightly the default multiplier from 0 to 0.1.
r? `@ghost`
Don't ICE when using `#[global_alloc]` on a non-item statement
Fixes#83469
We need to return an `Annotatable::Stmt` if we were passed an
`Annotatable::Stmt`
Refactor #82270 as lint instead of an error
This PR fixes several issues with #82270 which generated an error when `.intel_syntax` or `.att_syntax` was used in inline assembly:
- It is now a warn-by-default lint instead of an error.
- The lint only triggers on x86. `.intel_syntax` and `.att_syntax` are only valid on x86.
- The lint no longer provides machine-applicable suggestions for two reasons:
- These changes should not be made automatically since changes to assembly code can be very subtle.
- The template string is not always just a string: it can contain macro invocation (`concat!`), raw strings, escape characters, etc.
cc ``@asquared31415``
Allow for reading raw bytes from rustc_serialize::Decoder without unsafe code
The current `read_raw_bytes` method requires using `MaybeUninit` and `unsafe`. I don't think this is necessary. Let's see if a safe interface has any performance drawbacks.
This is a followup to #83273 and will make it easier to rebase #82183.
r? `@cjgillot`
Refactor rustc_resolve::late::lifetimes to resolve per-item
There are some changes to tests that I'd like some feedback on; so this is still WIP.
The reason behind this change will (hopefully) allow us to (as part of #76814) be able to essentially use the lifetime resolve code to resolve *all* late bound vars (including those of super traits). Currently, it only resolves those that are *syntactically* in scope. In #76814, I'm essentially finding that I would essentially have to redo the passing of bound vars through scopes (i.e. when instantiating a poly trait ref), and that's what this code does anyways. However, to be able to do this (ask super traits what bound vars are in scope), we have to be able to resolve items separately.
The first commit is actually partially orthogonal. Essentially removing one use of late bound debruijn indices.
Not exactly sure who would be best to review here.
Let r? `@nikomatsakis`
GenericParam does not need to be a HIR owner.
The special case is not required.
Universal impl traits design to regular generic parameters, and their content is owned by the enclosing item.
Existential (and opaque) impl traits generate their own enclosing item, and are collected through it.
coverage bug fixes and optimization support
Adjusted LLVM codegen for code compiled with `-Zinstrument-coverage` to
address multiple, somewhat related issues.
Fixed a significant flaw in prior coverage solution: Every counter
generated a new counter variable, but there should have only been one
counter variable per function. This appears to have bloated .profraw
files significantly. (For a small program, it increased the size by
about 40%. I have not tested large programs, but there is anecdotal
evidence that profraw files were way too large. This is a good fix,
regardless, but hopefully it also addresses related issues.
Fixes: #82144
Invalid LLVM coverage data produced when compiled with -C opt-level=1
Existing tests now work up to at least `opt-level=3`. This required a
detailed analysis of the LLVM IR, comparisons with Clang C++ LLVM IR
when compiled with coverage, and a lot of trial and error with codegen
adjustments.
The biggest hurdle was figuring out how to continue to support coverage
results for unused functions and generics. Rust's coverage results have
three advantages over Clang's coverage results:
1. Rust's coverage map does not include any overlapping code regions,
making coverage counting unambiguous.
2. Rust generates coverage results (showing zero counts) for all unused
functions, including generics. (Clang does not generate coverage for
uninstantiated template functions.)
3. Rust's unused functions produce minimal stubbed functions in LLVM IR,
sufficient for including in the coverage results; while Clang must
generate the complete LLVM IR for each unused function, even though
it will never be called.
This PR removes the previous hack of attempting to inject coverage into
some other existing function instance, and generates dedicated instances
for each unused function. This change, and a few other adjustments
(similar to what is required for `-C link-dead-code`, but with lower
impact), makes it possible to support LLVM optimizations.
Fixes: #79651
Coverage report: "Unexecuted instantiation:..." for a generic function
from multiple crates
Fixed by removing the aforementioned hack. Some "Unexecuted
instantiation" notices are unavoidable, as explained in the
`used_crate.rs` test, but `-Zinstrument-coverage` has new options to
back off support for either unused generics, or all unused functions,
which avoids the notice, at the cost of less coverage of unused
functions.
Fixes: #82875
Invalid LLVM coverage data produced with crate brotli_decompressor
Fixed by disabling the LLVM function attribute that forces inlining, if
`-Z instrument-coverage` is enabled. This attribute is applied to
Rust functions with `#[inline(always)], and in some cases, the forced
inlining breaks coverage instrumentation and reports.
FYI: `@wesleywiser`
r? `@tmandry`
LLVMWrapper: attractive nuisance macros
This came up in the review of #83425: it's hard to imagine a use of
LLVM_VERSION_LE() or LLVM_VERSION_EQ() that's not asking for trouble
when a point release gets created, so let's just discard them to prevent
the issue.
small cleanups in rustc_errors / emitter
This is either moving code around so it gets called less often or using if let instead of match in a few cases.
Fixes#80691
When we evaluate a trait predicate, we convert an
`EvaluatedToOk` result to `EvaluatedToOkModuloRegions` if we erased any
regions. We cache the result under a region-erased 'freshened'
predicate, so `EvaluatedToOk` may not be correct for other predicates
that have the same cache key.
THis came up in the review of #83425: it's hard to imagine a use of
LLVM_VERSION_LE() or LLVM_VERSION_EQ() that's not asking for trouble
when a point release gets created, so let's just discard them to prevent
the issue.
2229 migration: Don't try resolve regions before writeback
In the analysis use `resolve_vars_if_possible` instead of `fully_resolve`,
because we might not have performed regionck yet.
Fixes: #83176
r? `@nikomatsakis`
implement `feature(const_generics_defaults)`
Implements const generics defaults `struct Example<const N: usize=3>`, as well as a query for getting the default of a given const-parameter's def id. There are some remaining FIXME's but they were specified as not blocking for merging this PR. This also puts the defaults behind the unstable feature gate `#![feature(const_generics_defaults)]`.
~~This currently creates a field which is always false on `GenericParamDefKind` for future use when
consts are permitted to have defaults. I'm not sure if this is exactly what is best for adding default parameters, but I mimicked the style of type defaults, so hopefully this is ok.~~
r? `@lcnr`
Change `-W help` to display edition level.
`-W help` was not honoring the `--edition` flag when displaying the default lint level. It was using the edition for sorting, but not for the final display.
This isn't important right now as there aren't any edition-specific lint levels. Also, the `declare_lint` macro is broken and doesn't even allow setting them right now. However, I figure it wouldn't hurt to fix this before I forget about it, in case edition-specific lints are ever used in the future.
Allow not emitting `uwtable` on Android
`uwtable` is marked as required on Android, so it can't be disabled via `-C force-unwind-tables=no`. However, I found that the reason it's marked as required was to resolve a [backtrace issue in Gecko](https://github.com/rust-lang/rust/issues/49867), and I haven't find any other reasons that make it required ([yet](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/Unwind.20tables.20are.20strictly.20required.20on.20Windows.20and.20Android)). Therefore, I assume it's safe to turn it off if a (nice) backtrace is not needed, and submit this PR to allow `-C force-unwind-tables=no` when targeting Android.
Note that I haven't tested this change on Android as I don't have an Android environment for testing.
Only enable assert_dep_graph when query-dep-graph is enabled.
This is a debugging option. The only effect should be on rustc tests.
r? ``@michaelwoerister``
This currently creates a field which is always false on GenericParamDefKind for future use when
consts are permitted to have defaults
Update const_generics:default locations
Previously just ignored them, now actually do something about them.
Fix using type check instead of value
Add parsing
This adds all the necessary changes to lower const-generics defaults from parsing.
Change P<Expr> to AnonConst
This matches the arguments passed to instantiations of const generics, and makes it specific to
just anonymous constants.
Attempt to fix lowering bugs
rustc: changes to allow an llvm update
This lets LLVM be built using 2b5f3f446f36, which is only a few weeks old. The next change in LLVM (5de2d189e6ad) breaks rustc again by removing a function that's exposed into the Rust code, but I'll file a bug about that separately.
Please scrutinize the `thinLTOResolvePrevailingInIndex` call, as I'm not at all sure an empty config is right.
I'm also suspicious that a specific alignment could be specified in the call to CreateAtomicCmpXchg, but I don't know enough to figure that out.
Thanks!
