More consistently use spaces after commas in lists in docs
This PR changes instances of lists that didn't use spaces after commas, like `vec![1,2,3]`, to `vec![1, 2, 3]` to be more consistent with idiomatic Rust style (the way these were looks strange to me, especially because there are often lists that *do* use spaces after the commas later in the same code block 😬).
I noticed one of these in an example in the stdlib docs and went looking for more, but as far as I can see, I'm only changing those spots in user-facing documentation or rustc output, and the changes make no semantic difference.
Direct RUSTC_LOG (tracing/log) output to stderr instead of stdout.
Looks like this got missed in the initial implementation, AFAIK the old behavior was to output on stderr.
(Hit this while trying to debug `rustc` running inside a build script which was only letting stderr through)
r? ``@oli-obk`` cc ``@davidbarsky`` ``@hawkw``
Fix links to extern types in rustdoc (fixes#78777)
r? `@jyn514`
Fixes#78777.
The initial fix we tried was:
```diff
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 8be9482acff..c4b7086fdb1 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
`@@` -433,8 +433,9 `@@` impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
Res::PrimTy(prim) => Some(
self.resolve_primitive_associated_item(prim, ns, module_id, item_name, item_str),
),
- Res::Def(DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::TyAlias, did) => {
+ Res::Def(kind, did) if kind.ns() == Some(Namespace::TypeNS) => {
debug!("looking for associated item named {} for item {:?}", item_name, did);
+
// Checks if item_name belongs to `impl SomeItem`
let assoc_item = cx
.tcx
```
However, this caused traits to be matched, resulting in a panic when `resolve_associated_trait_item` is called further down in this function.
This PR also adds an error message for that panic. Currently it will look something like:
```rust
thread 'rustc' panicked at 'Not a type: DefIndex(8624)', compiler/rustc_metadata/src/rmeta/decoder.rs:951:32
```
I wasn't sure how to get a better debug output than `DefIndex(...)`, and am open to suggestions.
It is applied exactly when the return value has an indirect pass mode.
Except for InReg on x86 fastcall, arg attrs are now only used for
optimization purposes and thus are fine to ignore.
lint: Do not provide suggestions for non standard characters
Fixes#77273
Only provide suggestions if the case-fixed result is different than the original.
rustc_expand: Mark inner `#![test]` attributes as soft-unstable
Custom inner attributes are feature gated (https://github.com/rust-lang/rust/issues/54726) except for attributes having name `test` literally, which are not gated for historical reasons.
`#![test]` is an inner proc macro attribute, so it has all the issues described in https://github.com/rust-lang/rust/issues/54726 too.
This PR gates it with the `soft_unstable` lint.
Reworks Sccc computation to iteration instead of recursion
Linear graphs, producing as many scc's as nodes, would recurse once for every node when entered from the start of the list. This adds a test that exhausted the stack at least on my machine with error:
```
thread 'graph::scc::tests::test_deep_linear' has overflowed its stack
fatal runtime error: stack overflow
```
This may or may not be connected to #78567. I was only reminded that I started this rework some time ago. It might be plausible as borrow checking a long function with many borrow regions around each other—((((((…))))))— may produce the linear list setup to trigger this stack overflow ? I don't know enough about borrow check to say for sure.
This is best read in two separate commits. The first addresses only `find_state` internally. This is classical union phase from union-find. There's also a common solution of using the parent pointers in the (virtual) linked list to track the backreferences while traversing upwards and then following them backwards in a second path compression phase.
The second is more involved as it rewrites the mutually recursive `walk_node` and `walk_unvisited_node`. Firstly, the caller is required to handle the unvisited case of `walk_node` so a new `start_walk_from` method is added to handle that by walking the unvisited node if necessary. Then `walk_unvisited_node`, where we would previously recurse into in the missing case, is rewritten to construct a manual stack of its frames. The state fields consist of the previous stack slots.
Arena: use specialization to avoid copying data
In several cases, a `Vec` or `SmallVec` is passed to `Arena::alloc_from_iter` directly. This PR makes sure those cases don't copy their data unnecessarily, by specializing the `alloc_from_iter` implementation.
Never inline naked functions
The `#[naked]` attribute disabled prologue / epilogue emission for the
function and it is responsibility of a developer to provide them. The
compiler is no position to inline such functions correctly.
Disable inlining of naked functions at LLVM and MIR level.
Closes#60919.
Add lint for panic!("{}")
This adds a lint that warns about `panic!("{}")`.
`panic!(msg)` invocations with a single argument use their argument as panic payload literally, without using it as a format string. The same holds for `assert!(expr, msg)`.
This lints checks if `msg` is a string literal (after expansion), and warns in case it contained braces. It suggests to insert `"{}", ` to use the message literally, or to add arguments to use it as a format string.
This lint is also a good starting point for adding warnings about `panic!(not_a_string)` later, once [`panic_any()`](https://github.com/rust-lang/rust/pull/74622) becomes a stable alternative.
The `#[naked]` attribute disabled prologue / epilogue emission for the
function and it is responsibility of a developer to provide them. The
compiler is no position to inline such functions correctly.
Disable inlining of naked functions at LLVM and MIR level.
Move capture lowering from THIR to MIR
This allows us to:
- Handle precise Places captured by a closure directly in MIR. Handling
captures in MIR is easier since we can rely on/ tweak PlaceBuilder to
generate `mir::Place`s that resemble how we store captures (`hir::Place`).
- Handle `let _ = x` case when feature `capture_disjoint_fields`
is enabled directly in MIR. This is required to be done in MIR since
patterns are desugared in MIR.
Closes: rust-lang/project-rfc-2229#25
r? ```@nikomatsakis```
add optimization fuel checks to some mir passes
Fixes#77402
Inserts a bunch of calls to `consider_optimizing`. Note that `consider_optimizing` is the method that actually decrements the fuel count, so the point at which it's called is when the optimization takes place, from a fuel perspective. This means that where we call it has some thought behind it:
1. We probably don't want to decrement the fuel count before other simple checks, otherwise we count an optimization as being performed even if nothing was mutated (ie. it returned early).
2. In cases like `InstCombine`, where we gather optimizations in a pass and then mutate values, we probably would rather skip the gathering pass for performance reasons rather than skip the mutations afterwards.
Improve the diagnostic for when an `fn` contains qualifiers inside an `extern` block.
This mitigates #78941. As suggested by ```@estebank,``` `span_suggestion` was replaced with `span_suggestion_verbose` for this specific diagnostic.
Make bad "rust-call" arguments no longer ICE
The simplest of bad rust-call definitions will no longer cause an ICE. There is a FIXME added for future work, as I wanted to get this easy fix in before trying to either add a hack or mess with the whole obligation system
fixes#22565
Fix setting inline hint based on `InstanceDef::requires_inline`
For instances where `InstanceDef::requires_inline` is true, an attempt
is made to set an inline hint though a call to the `inline` function.
The attempt is ineffective, since all attributes will be usually removed
by the second call.
Fix the issue by applying the attributes only once, with user provided
attributes having a priority when provided.
Closes#79108.
Handle empty matches cleanly in exhaustiveness checking
This removes the special-casing of empty matches that was done in `check_match`. This fixes most of https://github.com/rust-lang/rust/issues/55123.
Somewhat unrelatedly, I also made `_match.rs` more self-contained, because I think it's cleaner.
r? `@varkor`
`@rustbot` modify labels: +A-exhaustiveness-checking
type is too big -> values of the type are too big
strictly speaking, `[u8; usize::MAX]` or even `[[[u128; usize::MAX]; usize::MAX]; usize::MAX]` are absolutely fine types as long as you don't try to deal with any values of it.
This error message seems to cause some confusion imo, for example in https://github.com/rust-lang/rust/pull/79135#issuecomment-729361380 so I would prefer us to be more precise here.
See the added test case which uses one of these types without causing an error.
r? ``@oli-obk``
Updated the list of white-listed target features for x86
This PR both adds in-source documentation on what to look out for when adding a new (X86) feature set and [adds all that are detectable at run-time in Rust stable as of 1.27.0](https://github.com/rust-lang/stdarch/blob/master/crates/std_detect/src/detect/arch/x86.rs).
This should only enable the use of the corresponding LLVM intrinsics.
Actual intrinsics need to be added separately in rust-lang/stdarch.
It also re-orders the run-time-detect test statements to be more consistent
with the actual list of intrinsics whitelisted and removes underscores not present
in the actual names (which might be mistaken as being part of the name)
The reference for LLVM's feature names used is [this file](https://github.com/llvm/llvm-project/blob/master/llvm/include/llvm/Support/X86TargetParser.def).
This PR was motivated as the compiler end's part for allowing #67329 to be adressed over on rust-lang/stdarch
ExprKind::SelfRef was used to express accessing `self` in
the desugared Closure/Generator struct when lowering captures in THIR.
Since we handle captures in MIR now, we don't need `ExprKind::Self`.
This allows us to:
- Handle precise Places captured by a closure directly in MIR. Handling
captures in MIR is easier since we can rely on/ tweak PlaceBuilder to
generate `mir::Place`s that resemble how we store captures (`hir::Place`).
- Allows us to handle `let _ = x` case when feature `capture_disjoint_fields`
is enabled directly in MIR. This is required to be done in MIR since
patterns are desugared in MIR.
[self-profiling] Include the estimated size of each cgu in the profile
This is helpful when looking for CGUs where the size estimate isn't a
good indicator of compilation time.
I verified that moving the profiling timer call doesn't affect the
results.
Results:
<img width="297" alt="Screen Shot 2020-11-03 at 7 25 04 AM" src="https://user-images.githubusercontent.com/831192/97985503-5901d100-1da6-11eb-9f10-f3e399702952.png">
`measureme` doesn't have support for custom arg names yet so `arg0` is the CGU name and `arg1` is the estimated size.
Rustdoc test compiler output color
Fixes#72915
We just need to be sure it doesn't break rustdoc doctests' compilation checks. Maybe some other unforeseen consequences too?
r? `@ehuss`
cc `@rust-lang/rustdoc`
Introduce `TypeVisitor::BreakTy`
Implements MCP rust-lang/compiler-team#383.
r? `@ghost`
cc `@lcnr` `@oli-obk`
~~Blocked on FCP in rust-lang/compiler-team#383.~~
RFC-2229: Implement Precise Capture Analysis
### This PR introduces
- Feature gate for RFC-2229 (incomplete) `capture_disjoint_field`
- Rustc Attribute to print out the capture analysis `rustc_capture_analysis`
- Precise capture analysis
### Description of the analysis
1. If the feature gate is not set then all variables that are not local to the closure will be added to the list of captures. (This is for backcompat)
2. The rest of the analysis is based entirely on how the captured `Place`s are used within the closure. Precise information (i.e. projections) about the `Place` is maintained throughout.
3. To reduce the amount of information we need to keep track of, we do a minimization step. In this step, we determine a list such that no Place within this list represents an ancestor path to another entry in the list. Check rust-lang/project-rfc-2229#9 for more detailed examples.
4. To keep the compiler functional as before we implement a Bridge between the results of this new analysis to existing data structures used for closure captures. Note the new capture analysis results are only part of MaybeTypeckTables that is the information is only available during typeck-ing.
### Known issues
- Statements like `let _ = x` will make the compiler ICE when used within a closure with the feature enabled. More generally speaking the issue is caused by `let` statements that create no bindings and are init'ed using a Place expression.
### Testing
We removed the code that would handle the case where the feature gate is not set, to enable the feature as default and did a bors try and perf run. More information here: #78762
### Thanks
This has been slowly in the works for a while now.
I want to call out `@Azhng` `@ChrisPardy` `@null-sleep` `@jenniferwills` `@logmosier` `@roxelo` for working on this and the previous PRs that led up to this, `@nikomatsakis` for guiding us.
Closesrust-lang/project-rfc-2229#7Closesrust-lang/project-rfc-2229#9Closesrust-lang/project-rfc-2229#6Closesrust-lang/project-rfc-2229#19
r? `@nikomatsakis`
For instances where `InstanceDef::requires_inline` is true, an attempt
is made to set an inline hint though a call to the `inline` function.
The attempt is ineffective, since all attributes will be usually removed
by the second call.
Fix the issue by applying the attributes only once, with user provided
attributes having a priority when provided.
Update E0744 about control flow in `const` contexts to accurately describe when the error is triggered and why
This PR fixes#79083. `const fn` currently supports `if`, `match`, `loop`, and `while` in terms of control flow. The error relating to control flow in `const` contexts currently states that those control flow constructs are not allowed in `const` contexts. That is no longer true, as RFC 2342 and 2344 were [stabilized](https://github.com/rust-lang/rust/pull/72437). `for` loops, however, as well as `?` and `.await` are still not allowed, so I changed the error message to be more descriptive of the error as it is not just control flow that could trigger this error. I also added links to tracking issues that mark things that are blocking the usage of these expressions.
improve type const mismatch errors
Doesn't completely remove `check_generic_arg_count` as that would have required some more complex changes but
instead checks type and const params in only one step. Also moved the help added by `@JulianKnodt` in #75611 to `generic_arg_mismatch_err`.
r? `@varkor` cc `@petrochenkov`
Simplify output capturing
This is a sequence of incremental improvements to the unstable/internal `set_panic` and `set_print` mechanism used by the `test` crate:
1. Remove the `LocalOutput` trait and use `Arc<Mutex<dyn Write>>` instead of `Box<dyn LocalOutput>`. In practice, all implementations of `LocalOutput` were just `Arc<Mutex<..>>`. This simplifies some logic and removes all custom `Sink` implementations such as `library/test/src/helpers/sink.rs`. Also removes a layer of indirection, as the outermost `Box` is now gone. It also means that locking now happens per `write_fmt`, not per individual `write` within. (So `"{} {}\n"` now results in one `lock()`, not four or more.)
2. Since in all cases the `dyn Write`s were just `Vec<u8>`s, replace the type with `Arc<Mutex<Vec<u8>>>`. This simplifies things more, as error handling and flushing can be removed now. This also removes the hack needed in the default panic handler to make this work with `::realstd`, as (unlike `Write`) `Vec<u8>` is from `alloc`, not `std`.
3. Replace the `RefCell`s by regular `Cell`s. The `RefCell`s were mostly used as `mem::replace(&mut *cell.borrow_mut(), something)`, which is just `Cell::replace`. This removes an unecessary bookkeeping and makes the code a bit easier to read.
4. Merge `set_panic` and `set_print` into a single `set_output_capture`. Neither the test crate nor rustc (the only users of this feature) have a use for using these separately. Merging them simplifies things even more. This uses a new function name and feature name, to make it clearer this is internal and not supposed to be used by other crates.
Might be easier to review per commit.
This is a squash of these commits:
- Update E0744 about control flow in `const` contexts to reflect current status of `const fn`.
- E0744 isn't just about `for` loops or control flow
- Fix formatting on E0744 cause my editor decided to not copy it well
- Improve wording
- Fix a markdown formatting error
- Fix E0744's description as I interpreted some code wrong
- Fix a minor wording issue again
- Add a few more links to blocking issues
- Improve links to tracking issues
Clippy uses `ExprUseVisitor` and atleast in some cases it runs
after writeback.
We currently don't writeback the min_capture results of closure
capture analysis since no place within the compiler itself uses it.
In the short term to fix clippy we add a fallback when walking captures
of a closure to check if closure_capture analysis has any entries in it.
Writeback for closure_min_captures will be implemented in
rust-lang/project-rfc-2229#18
Move likely/unlikely argument outside of invisible unsafe block
The previous `likely!`/`unlikely!` macros were unsound because it permits the caller's expr to contain arbitrary unsafe code.
```rust
pub fn huh() -> bool {
likely!(std::ptr::read(&() as *const () as *const bool))
}
```
**Before:** compiles cleanly.
**After:**
```console
error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
|
70 | likely!(std::ptr::read(&() as *const () as *const bool))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ call to unsafe function
|
= note: consult the function's documentation for information on how to avoid undefined behavior
```
astconv: extract closures into a separate trait
Am currently looking into completely removing `check_generic_arg_count` and `create_substs_for_generic_args` was somewhat difficult to understand for me so I moved these closures into a trait.
This should not have changed the behavior of any of these methods
Make `_` an expression, to discard values in destructuring assignments
This is the third and final step towards implementing destructuring assignment (RFC: rust-lang/rfcs#2909, tracking issue: #71126). This PR is the third and final part of #71156, which was split up to allow for easier review.
With this PR, an underscore `_` is parsed as an expression but is allowed *only* on the left-hand side of a destructuring assignment. There it simply discards a value, similarly to the wildcard `_` in patterns. For instance,
```rust
(a, _) = (1, 2)
```
will simply assign 1 to `a` and discard the 2. Note that for consistency,
```
_ = foo
```
is also allowed and equivalent to just `foo`.
Thanks to ````@varkor```` who helped with the implementation, particularly around pre-expansion gating.
r? ````@petrochenkov````
cleanup: Remove `ParseSess::injected_crate_name`
Its only remaining use is in pretty-printing where the necessary information can be easily re-computed.
Allow making `RUSTC_BOOTSTRAP` conditional on the crate name
Motivation: This came up in the [Zulip stream](https://rust-lang.zulipchat.com/#narrow/stream/233931-t-compiler.2Fmajor-changes/topic/Require.20users.20to.20confirm.20they.20know.20RUSTC_.E2.80.A6.20compiler-team.23350/near/208403962) for https://github.com/rust-lang/compiler-team/issues/350.
See also https://github.com/rust-lang/cargo/pull/6608#issuecomment-458546258; this implements https://github.com/rust-lang/cargo/issues/6627.
The goal is for this to eventually allow prohibiting setting `RUSTC_BOOTSTRAP` in build.rs (https://github.com/rust-lang/cargo/issues/7088).
## User-facing changes
- `RUSTC_BOOTSTRAP=1` still works; there is no current plan to remove this.
- Things like `RUSTC_BOOTSTRAP=0` no longer activate nightly features. In practice this shouldn't be a big deal, since `RUSTC_BOOTSTRAP` is the opposite of stable and everyone uses `RUSTC_BOOTSTRAP=1` anyway.
- `RUSTC_BOOTSTRAP=x` will enable nightly features only for crate `x`.
- `RUSTC_BOOTSTRAP=x,y` will enable nightly features only for crates `x` and `y`.
## Implementation changes
The main change is that `UnstableOptions::from_environment` now requires
an (optional) crate name. If the crate name is unknown (`None`), then the new feature is not available and you still have to use `RUSTC_BOOTSTRAP=1`. In practice this means the feature is only available for `--crate-name`, not for `#![crate_name]`; I'm interested in supporting the second but I'm not sure how.
Other major changes:
- Added `Session::is_nightly_build()`, which uses the `crate_name` of
the session
- Added `nightly_options::match_is_nightly_build`, a convenience method
for looking up `--crate-name` from CLI arguments.
`Session::is_nightly_build()`should be preferred where possible, since
it will take into account `#![crate_name]` (I think).
- Added `unstable_features` to `rustdoc::RenderOptions`
I'm not sure whether this counts as T-compiler or T-lang; _technically_ RUSTC_BOOTSTRAP is an implementation detail, but it's been used so much it seems like this counts as a language change too.
r? `@joshtriplett`
cc `@Mark-Simulacrum` `@hsivonen`
Clean up outdated `use_once_payload` pretty printer comment
While reading some parts of the pretty printer code, I noticed this old comment
which seemed out of place. The `use_once_payload` this outdated comment mentions
was removed in 2017 in 40f03a1e0d, so this
completes the work by removing the comment.
Fix rustc_ast_pretty print_qpath resulting in invalid macro input
related https://github.com/rust-lang/rust/issues/76874 (third case)
### Issue:
The input for a procedural macro is incorrect, for the rust code:
```rust
mod m {
pub trait Tr {
type Ts: super::Tu;
}
}
trait Tu {
fn dummy() { }
}
#[may_proc_macro]
fn foo() {
<T as m::Tr>::Ts::dummy();
}
```
the macro will get the input:
```rust
fn foo() {
<T as m::Tr>::dummy();
}
```
Thus `Ts` has disappeared.
### Fix:
This is due to invalid pretty print of qpath. This PR fix it.
Normalize function type during validation
During inlining, the callee body is normalized and has types revealed,
but some of locals corresponding to the arguments might come from the
caller body which is not. As a result the caller body does not pass
validation without additional normalization.
Closes#78442.
Do not call `unwrap` with `signatures` option enabled
Fixes#75229
Didn't add a test since I couldn't set `RUST_SAVE_ANALYSIS_CONFIG` even with `rustc-env`.
Lower intrinsics calls: forget, size_of, unreachable, wrapping_*
This allows constant propagation to evaluate `size_of` and `wrapping_*`,
and unreachable propagation to propagate a call to `unreachable`.
The lowering is performed as a MIR optimization, rather than during MIR
building to preserve the special status of intrinsics with respect to
unsafety checks and promotion.
Currently enabled by default to determine the performance impact (no
significant impact expected). In practice only useful when combined with
inlining since intrinsics are rarely used directly (with exception of
`unreachable` and `discriminant_value` used by built-in derive macros).
Closes#32716.
The previous `likely!`/`unlikely!` macros were unsound because it
permits the caller's expr to contain arbitrary unsafe code.
pub fn huh() -> bool {
likely!(std::ptr::read(&() as *const () as *const bool))
}
Before: compiles cleanly.
After:
error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
|
70 | likely!(std::ptr::read(&() as *const () as *const bool))
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ call to unsafe function
|
= note: consult the function's documentation for information on how to avoid undefined behavior
Previously, cap-lints was ignored when checking the previous forbid level, which
meant that it was a hard error to do so. This is different from the normal
behavior of lints, which are silenced by cap-lints; if the forbid would not take
effect regardless, there is not much point in complaining about the fact that we
are reducing its level.
It might be considered a bug that even `--cap-lints deny` would suffice to
silence the error on overriding forbid, depending on if one cares about failing
the build or precisely forbid being set. But setting cap-lints to deny is quite
odd and not really done in practice, so we don't try to handle it specially.
This also unifies the code paths for nested and same-level scopes. However, the
special case for CLI lint flags is left in place (introduced by #70918) to fix
the regression noted in #70819. That means that CLI flags do not lint on forbid
being overridden by a non-forbid level. It is unclear whether this is a bug or a
desirable feature, but it is certainly inconsistent. CLI flags are a
sufficiently different "type" of place though that this is deemed out of scope
for this commit.
add error_occured field to ConstQualifs,
fix#76064
I wasn't sure what `in_return_place` actually did and not sure why it returns `ConstQualifs` while it's sibling functions return `bool`. So I tried to make as minimal changes to the structure as possible. Please point out whether I have to refactor it or not.
r? `@oli-obk`
cc `@RalfJung`
rustc_target: Mark UEFI targets as `is_like_windows`/`is_like_msvc`
And document what `is_like_windows` and `is_like_msvc` actually mean in more detail.
Addresses FIXMEs left from https://github.com/rust-lang/rust/pull/71030.
r? `@nagisa`
rustc_parse: Remove optimization for 0-length streams in `collect_tokens`
The optimization conflates empty token streams with unknown token stream, which is at least suspicious, and doesn't affect performance because 0-length token streams are very rare.
r? `@Aaron1011`
This allows constant propagation to evaluate `size_of` and `wrapping_*`,
and unreachable propagation to propagate a call to `unreachable`.
The lowering is performed as a MIR optimization, rather than during MIR
building to preserve the special status of intrinsics with respect to
unsafety checks and promotion.
Add type to `ConstKind::Placeholder`
I simply threaded `<'tcx>` through everything that required it. I'm not sure whether this is the correct thing to do, but it seems to work.
r? `@nikomatsakis`
While reading some parts of the pretty printer code, I noticed this old comment
which seemed out of place. The `use_once_payload` this outdated comment mentions
was removed in 2017 in 40f03a1e0d, so this
completes the work by removing the comment.
During inlining, the callee body is normalized and has types revealed,
but some of locals corresponding to the arguments might come from the
caller body which is not. As a result the caller body does not pass
validation without additional normalization.
The optimization conflates empty token streams with unknown token stream, which is at least suspicious, and doesn't affect performance because 0-length token streams are very rare.
The inliner looks if a sanitizer is enabled before considering
`no_sanitize` attribute as possible source of incompatibility.
The MIR inlining could happen in a crate with sanitizer disabled, but
code generation in a crate with sanitizer enabled, thus the attribute
would be incorrectly ignored.
To avoid the issue never inline functions with different `no_sanitize`
attributes.
Add asm register information for SPIR-V
As discussed in [zulip](https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/Defining.20asm!.20for.20new.20architecture), we at [rust-gpu](https://github.com/EmbarkStudios/rust-gpu) would like to support `asm!` for our SPIR-V backend. However, we cannot do so purely without frontend support: [this match](d4ea0b3e46/compiler/rustc_target/src/asm/mod.rs (L185)) fails and so `asm!` is not supported ([error reported here](d4ea0b3e46/compiler/rustc_ast_lowering/src/expr.rs (L1095))). To resolve this, we need to stub out register information for SPIR-V to support getting the `asm!` content all the way to [`AsmBuilderMethods::codegen_inline_asm`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_codegen_ssa/traits/trait.AsmBuilderMethods.html#tymethod.codegen_inline_asm), at which point the rust-gpu backend can do all the parsing and codegen that is needed.
This is a pretty weird PR - adding support for a backend that isn't in-tree feels pretty gross to me, but I don't see an easy way around this. ``@Amanieu`` said I should submit it anyway, so, here we are! Let me know if this needs to go through a more formal process (MCP?) and what I should do to help this along.
I based this off the [wasm asm PR](https://github.com/rust-lang/rust/pull/78684), which unfortunately this PR conflicts with that one quite a bit, sorry for any merge conflict pain :(
---
Some open questions:
- What do we call the register class? Some context, SPIR-V is an SSA-based IR, there are "instructions" that create IDs (referred to as `<id>` in the spec), which can be referenced by other instructions. So, `reg` isn't exactly accurate, they're SSA IDs, not re-assignable registers.
- What happens when a SPIR-V register gets to the LLVM backend? Right now it's a `bug!`, but should that be a `sess.fatal()`? I'm not sure if it's even possible to reach that point, maybe there's a check that prevents the `spirv` target from even reaching that codepath.
Implement destructuring assignment for structs and slices
This is the second step towards implementing destructuring assignment (RFC: rust-lang/rfcs#2909, tracking issue: #71126). This PR is the second part of #71156, which was split up to allow for easier review.
Note that the first PR (#78748) is not merged yet, so it is included as the first commit in this one. I thought this would allow the review to start earlier because I have some time this weekend to respond to reviews. If ``@petrochenkov`` prefers to wait until the first PR is merged, I totally understand, of course.
This PR implements destructuring assignment for (tuple) structs and slices. In order to do this, the following *parser change* was necessary: struct expressions are not required to have a base expression, i.e. `Struct { a: 1, .. }` becomes legal (in order to act like a struct pattern).
Unfortunately, this PR slightly regresses the diagnostics implemented in #77283. However, it is only a missing help message in `src/test/ui/issues/issue-77218.rs`. Other instances of this diagnostic are not affected. Since I don't exactly understand how this help message works and how to fix it yet, I was hoping it's OK to regress this temporarily and fix it in a follow-up PR.
Thanks to ``@varkor`` who helped with the implementation, particularly around the struct rest changes.
r? ``@petrochenkov``
Reusing bindings causes errors later in lowering:
```
error[E0596]: cannot borrow `vec` as mutable, as it is not declared as mutable
--> /checkout/src/test/ui/async-await/argument-patterns.rs:12:20
|
LL | async fn b(n: u32, ref mut vec: A) {
| ^^^^^^^^^^^
| |
| cannot borrow as mutable
| help: consider changing this to be mutable: `mut vec`
```
incr-comp: hash and serialize span end line/column
Hash both the length and the end location (line/column) of a span. If we
hash only the length, for example, then two otherwise equal spans with
different end locations will have the same hash. This can cause a
problem during incremental compilation wherein a previous result for a
query that depends on the end location of a span will be incorrectly
reused when the end location of the span it depends on has changed. A
similar analysis applies if some query depends specifically on the
length of the span, but we only hash the end location. So hash both.
Fix#46744, fix#59954, fix#63161, fix#73640, fix#73967, fix#74890, fix#75900
---
See #74890 for a more in-depth analysis.
I haven't thought about what other problems this root cause could be responsible for. Please let me know if anything springs to mind. I believe the issue has existed since the inception of incremental compilation.
This commit grepped for LLVM_VERSION_GE, LLVM_VERSION_LT, get_major_version and
min-llvm-version and statically evaluated every expression possible
(and sensible) assuming that the LLVM version is >=9 now
Do not collect tokens for doc comments
Doc comment is a single token and AST has all the information to re-create it precisely.
Doc comments are also responsible for majority of calls to `collect_tokens` (with `num_calls == 1` and `num_calls == 0`, cc https://github.com/rust-lang/rust/pull/78736).
(I also moved token collection into `fn parse_attribute` to deduplicate code a bit.)
r? `@Aaron1011`
rustc_target: Move target env "gnu" from `linux_base` to `linux_gnu_base`
Follow up to https://github.com/rust-lang/rust/pull/77729.
Changes the target spec hierarchy for Linux from
```
linux_base
├── linux_musl_base
└── linux_uclibc_base
```
where `linux_base` is really `linux_gnu_base` and the inheriting targets replace target env "gnu" with "musl"/"uclibc" to
```
linux_base
├── linux_gnu_base
├── linux_musl_base
└── linux_uclibc_base
```
which is slightly less confusing (I think).
Support inlining diverging function calls
The existing heuristic does penalize diverging calls to some degree, but since
it never inlined them previously it might need some further modifications.
Additionally introduce storage markers for all temporaries created by
the inliner. The temporary introduced for destination rebrorrow, didn't
use them previously.
Add flags customizing behaviour of MIR inlining
* `-Zinline-mir-threshold` to change the default threshold.
* `-Zinline-mir-hint-threshold` to change the threshold used by
functions with inline hint.
Having those as configurable flags makes it possible to experiment with with
different inlining thresholds and substantially increase test coverage of MIR
inlining when used with increased thresholds (for example, necessary to test
#78844).
look at assoc ct, check the type of nodes
an example where types matter are function objects, see the added test which previously passed.
Now does a shallow comparison of unevaluated constants.
r? ```@oli-obk```
Majority of targets use "unknown" vendor and changing it from "unknown" to omitted doesn't make sense.
From the LLVM docs (https://clang.llvm.org/docs/CrossCompilation.html#target-triple):
>Most of the time it can be omitted (and Unknown) will be assumed, which sets the defaults for the specified architecture.
>When a parameter is not important, it can be omitted, or you can choose unknown and the defaults will be used. If you choose a parameter that Clang doesn’t know, like blerg, it’ll ignore and assume unknown
The discussion seems to have resolved that this lint is a bit "noisy" in
that applying it in all places would result in a reduction in
readability.
A few of the trivial functions (like `Path::new`) are fine to leave
outside of closures.
The general rule seems to be that anything that is obviously an
allocation (`Box`, `Vec`, `vec![]`) should be in a closure, even if it
is a 0-sized allocation.
It was only ever used with Vec<u8> anyway. This simplifies some things.
- It no longer needs to be flushed, because that's a no-op anyway for
a Vec<u8>.
- Writing to a Vec<u8> never fails.
- No #[cfg(test)] code is needed anymore to use `realstd` instead of
`std`, because Vec comes from alloc, not std (like Write).
Add comments to explain memory usage optimization
Add explanatory comments so that people understand that it's just an optimization and doesn't affect behavior.
rustc_target: Further cleanup use of target options
Follow up to https://github.com/rust-lang/rust/pull/77729.
Implements items 2 and 4 from the list in https://github.com/rust-lang/rust/pull/77729#issue-500228243.
The first commit collapses uses of `target.options.foo` into `target.foo`.
The second commit renames some target options to avoid tautology:
`target.target_endian` -> `target.endian`
`target.target_c_int_width` -> `target.c_int_width`
`target.target_os` -> `target.os`
`target.target_env` -> `target.env`
`target.target_vendor` -> `target.vendor`
`target.target_family` -> `target.os_family`
`target.target_mcount` -> `target.mcount`
r? `@Mark-Simulacrum`
Assert that a return place is not used for indexing during integration
The inliner integrates call destination place with callee return place
by remapping the local and adding extra projections as necessary.
If a call destination place contains any projections (which is already
possible) and a return place is used in an indexing projection (most
likely doesn't happen yet) the end result would be incorrect.
Add an assertion to ensure that potential issue won't go unnoticed in
the presence of more sophisticated copy propagation scheme.
Make it more clear what an about async fn's returns when referring to what it returns
see #76547
This is *likely* not the ONLY place that this happens to be unclear, but we can move this fn to rustc_middle or something like that and reuse it if need be, to apply it to more diagnostics
One outstanding question I have is, if the fn returns (), should I make the message more clear (what about `fn f()` vs `fn f() -> ()`, can you tell those apart in the hir?)
R? `@tmandry`
`@rustbot` modify labels +A-diagnostics +T-compiler
* `-Zinline-mir-threshold` to change the default threshold.
* `-Zinline-mir-hint-threshold` to change the threshold used by
functions with inline hint.
Monomorphize a type argument of size-of operation during codegen
This wasn't necessary until MIR inliner started to consider drop glue as
a candidate for inlining; introducing for the first time a generic use
of size-of operation.
No test at this point since this only happens with a custom inlining
threshold.
rustc_ast: Do not panic by default when visiting macro calls
Panicking by default made sense when we didn't have HIR or MIR and everything worked on AST, but now all AST visitors run early and majority of them have to deal with macro calls, often by ignoring them.
The second commit renames `visit_mac` to `visit_mac_call`, the corresponding structures were renamed earlier in https://github.com/rust-lang/rust/pull/69589.
inliner: Break inlining cycles
Keep track of all instances inlined so far. When examining a new call
sites from an inlined body, skip those where callee had been inlined
already to avoid potential inlining cycles.
Fixes#78573.
Improve lifetime name annotations for closures & async functions
* Don't refer to async functions as "generators" in error output
* Where possible, emit annotations pointing exactly at the `&` in the return type of closures (when they have explicit return types) and async functions, like we do for arguments.
Addresses #74072, but I wouldn't call that *closed* until annotations are identical for async and non-async functions.
* Emit a better annotation when the lifetime doesn't appear in the full name type, which currently happens for opaque types like `impl Future`. Addresses #74497, but further improves could probably be made (why *doesn't* it appear in the type as `impl Future + '1`?)
This is included in the same PR because the changes to `give_name_if_anonymous_region_appears_in_output` would introduce ICE otherwise (it would return `None` in cases where it didn't previously, which then gets `unwrap`ped)
gsgdt [https://crates.io/crates/gsgdt] is a crate which provides an
interface for stringly typed graphs. It also provides generation of
graphviz dot format from said graph.
Implement destructuring assignment for tuples
This is the first step towards implementing destructuring assignment (RFC: https://github.com/rust-lang/rfcs/pull/2909, tracking issue: #71126). This PR is the first part of #71156, which was split up to allow for easier review.
Quick summary: This change allows destructuring the LHS of an assignment if it's a (possibly nested) tuple.
It is implemented via a desugaring (AST -> HIR lowering) as follows:
```rust
(a,b) = (1,2)
```
... becomes ...
```rust
{
let (lhs0,lhs1) = (1,2);
a = lhs0;
b = lhs1;
}
```
Thanks to `@varkor` who helped with the implementation, particularly around default binding modes.
r? `@petrochenkov`
inliner: Use substs_for_mir_body
Changes from 68965 extended the kind of instances that are being
inlined. For some of those, the `instance_mir` returns a MIR body that
is already expressed in terms of the types found in substitution array,
and doesn't need further substitution.
Use `substs_for_mir_body` to take that into account.
Resolves#78529.
Resolves#78560.
Fix handling of item names for HIR
- Handle variants, fields, macros in `Node::ident()`
- Handle the crate root in `opt_item_name`
- Rewrite `item_name` in terms of `opt_item_name`
I need this for both https://github.com/rust-lang/rust/pull/77820 and https://github.com/rust-lang/rust/pull/78082, so splitting it out into a separate PR so it can land early.
Recognize `private_intra_doc_links` as a lint
Previously, trying to allow this would give another error!
```
warning: unknown lint: `private_intra_doc_links`
--> private.rs:1:10
|
1 | #![allow(private_intra_doc_links)]
| ^^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `broken_intra_doc_links`
|
= note: `#[warn(unknown_lints)]` on by default
warning: public documentation for `DocMe` links to private item `DontDocMe`
--> private.rs:2:11
|
2 | /// docs [DontDocMe]
| ^^^^^^^^^ this item is private
|
= note: `#[warn(private_intra_doc_links)]` on by default
= note: this link will resolve properly if you pass `--document-private-items`
```
Fixes the issue found in https://github.com/rust-lang/rust/pull/77249#issuecomment-712339227.
r? ````````@Manishearth````````
Does anyone know why this additional step is necessary? It seems weird this has to be declared in 3 different places.
Refactor IntErrorKind to avoid "underflow" terminology
This PR is a continuation of #76455
# Changes
- `Overflow` renamed to `PosOverflow` and `Underflow` renamed to `NegOverflow` after discussion in #76455
- Changed some of the parsing code to return `InvalidDigit` rather than `Empty` for strings "+" and "-". https://users.rust-lang.org/t/misleading-error-in-str-parse-for-int-types/49178
- Carry the problem `char` with the `InvalidDigit` variant.
- Necessary changes were made to the compiler as it depends on `int_error_matching`.
- Redid tests to match on specific errors.
r? ```@KodrAus```
Additionally introduce storage markers for all temporaries created by
the inliner. The temporary introduced for destination rebrorrow, didn't
use them previously.
When examining candidates for inlining, reject those that are determined
to be recursive either because of self-recursive calls or calls to any
instances already inlined.
rustc_ast: Visit tokens stored in AST nodes in mutable visitor
After #77271 token visiting is enabled only for one visitor in `rustc_expand\src\mbe\transcribe.rs` which applies hygiene marks to tokens produced by declarative macros (`macro_rules` or `macro`), so this change doesn't affect anything else.
When a macro has some interpolated token from an outer macro in its output
```rust
macro inner() {
$interpolated
}
```
we can use the usual interpretation of interpolated tokens in token-based model - a None-delimited group - to write this macro in an equivalent form
```rust
macro inner() {
⟪ a b c d ⟫
}
```
When we are expanding the macro `inner` we need to apply hygiene marks to all tokens produced by it, including the tokens inside the group.
Before this PR we did this by visiting the AST piece inside the interpolated token and applying marks to all spans in it.
I'm not sure this is 100% correct (ideally we should apply the marks to tokens and then re-parse the AST from tokens), but it's a very good approximation at least.
We didn't however apply the marks to actual tokens stored in the nonterminal, so if we used the nonterminal as a token rather than as an AST piece (e.g. passed it to a proc macro), then we got hygiene bugs.
This PR applies the marks to tokens in addition to the AST pieces thus fixing the issue.
r? `@Aaron1011`
This allows constructing the sccc for large that visit many nodes before
finding a single cycle of sccc, for example lists. When used to find
dependencies in borrow checking the list case is what occurs in very
long functions.
with an eye on merging `TargetOptions` into `Target`.
`TargetOptions` as a separate structure is mostly an implementation detail of `Target` construction, all its fields logically belong to `Target` and available from `Target` through `Deref` impls.
Rollup of 19 pull requests
Successful merges:
- #76097 (Stabilize hint::spin_loop)
- #76227 (Stabilize `Poll::is_ready` and `is_pending` as const)
- #78065 (make concurrency helper more pleasant to read)
- #78570 (Remove FIXME comment in print_type_sizes ui test suite)
- #78572 (Use SOCK_CLOEXEC and accept4() on more platforms.)
- #78658 (Add a tool to run `x.py` from any subdirectory)
- #78706 (Fix run-make tests running when LLVM is disabled)
- #78728 (Constantify `UnsafeCell::into_inner` and related)
- #78775 (Bump Rustfmt and RLS)
- #78788 (Correct unsigned equivalent of isize to be usize)
- #78811 (Make some std::io functions `const`)
- #78828 (use single char patterns for split() (clippy::single_char_pattern))
- #78841 (Small cleanup in `TypeFoldable` derive macro)
- #78842 (Honor the rustfmt setting in config.toml)
- #78843 (Less verbose debug logging from inlining integrator)
- #78852 (Convert a bunch of intra-doc links)
- #78860 (rustc_resolve: Use `#![feature(format_args_capture)]`)
- #78861 (typo and formatting)
- #78865 (Don't fire `CONST_ITEM_MUTATION` lint when borrowing a deref)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Don't fire `CONST_ITEM_MUTATION` lint when borrowing a deref
Fixes#78819
This extends the check for dereferences added in PR #77324
to cover mutable borrows, as well as direct writes. If we're operating
on a dereference of a `const` item, we shouldn't be firing the lint.
rustc_resolve: Use `#![feature(format_args_capture)]`
This is the best new sugar for quite some time.
(I only changed places that already used named arguments.)
Less verbose debug logging from inlining integrator
The inlining integrator produces relatively verbose and uninteresting
logs. Move them from a debug log level to a trace level, so that they
can be easily isolated from others.
revert #75443, update mir validator
This PR reverts rust-lang#75443 to fix rust-lang#75992 and instead uses rust-lang#75419 to fix rust-lang#75313.
Adapts rust-lang#75419 to correctly deal with unevaluated constants as otherwise some `feature(const_evaluatable_checked)` tests would ICE.
Note that rust-lang#72793 was also fixed by rust-lang#75443, but as that issue only concerns `feature(type_alias_impl_trait)` I deleted that test case for now and would reopen that issue.
rust-lang#75443 may have also allowed some other code to now successfully compile which would make this revert a breaking change after 2 stable versions, but I hope that this is a purely theoretical concern.
See https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/generator.20upvars/near/214617274 for more reasoning about this.
r? `@nikomatsakis` `@eddyb` `@RalfJung`
rustc_target: Move some target options from `Target` to `TargetOptions`
The only reason for `Target` to `TargetOptions` to be separate structures is that options in `TargetOptions` have reasonable defaults and options in `Target` don't.
(Otherwise all the options logically belong to a single `Target` struct.)
This PR moves a number of options with reasonable defaults from `Target` to `TargetOptions`, so they no longer needs to be specified explicitly for majority of the targets.
The move also allows to inherit the options from `rustc_target/src/spec/*_base.rs` files in a nicer way.
I didn't change any specific option values here.
The moved options are `target_c_int_width` (defaults to `"32"`), `target_endian` (defaults to `"little"`), `target_os` (defaults to `"none"`), `target_env` (defaults to `""`), `target_vendor` (defaults to `"unknown"`) and `linker_flavor` (defaults to `LinkerFlavor::Gcc`).
Next steps (in later PRs):
- Find a way to merge `TargetOptions` into `Target`
- If not, always access `TargetOptions` fields through `Deref` making it a part of `Target` at least logically (`session.target.target.options.foo` -> `session.target.target.foo`)
- ~Eliminate `session::config::Config` and use `Target` instead (`session.target.target.foo` -> `session.target.foo`)~ Done in https://github.com/rust-lang/rust/pull/77943.
- Avoid tautologies in option names (`target.target_os` -> `target.os`)
- Resolve _ https://github.com/rust-lang/rust/issues/77730 (rustc_target: The differences between `target_os = "none"` and `target_os = "unknown"`, and `target_vendor = "unknown"` and `target_vendor = ""` are unclear) noticed during implementation of this PR.
This PR allows using `#[repr(simd)]` on ADTs containing a
single array field:
```rust
#[repr(simd)] struct S0([f32; 4]);
#[repr(simd)] struct S1<const N: usize>([f32; N]);
#[repr(simd)] struct S2<T, const N: usize>([T; N]);
```
This should allow experimenting with portable packed SIMD
abstractions on nightly that make use of const generics.
Fixes#78819
This extends the check for dereferences added in PR #77324
to cover mutable borrows, as well as direct writes. If we're operating
on a dereference of a `const` item, we shouldn't be firing the lint.
Revert "Revert "resolve: Avoid "self-confirming" import resolutions in one more case""
Specifically, this reverts commit b20bce8ce5 from #77421 to fix#77586.
The lang team has decided that for the time being we want to avoid the breakage here (perhaps for a future edition; though almost certainly not the upcoming one), though a future PR may want to add a lint around this case (and perhaps others) which are unlikely to be readable code.
r? `@petrochenkov` to confirm this is the right way to fix#77586.
The inlining integrator produces relatively verbose and uninteresting
logs. Move them from a debug log level to a trace level, so that they
can be easily isolated from others.
The main change is that `UnstableOptions::from_environment` now requires
an (optional) crate name. If the crate name is unknown (`None`), then the new feature is not available and you still have to use `RUSTC_BOOTSTRAP=1`. In practice this means the feature is only available for `--crate-name`, not for `#![crate_name]`; I'm interested in supporting the second but I'm not sure how.
Other major changes:
- Added `Session::is_nightly_build()`, which uses the `crate_name` of
the session
- Added `nightly_options::match_is_nightly_build`, a convenience method
for looking up `--crate-name` from CLI arguments.
`Session::is_nightly_build()`should be preferred where possible, since
it will take into account `#![crate_name]` (I think).
- Added `unstable_features` to `rustdoc::RenderOptions`
There is a user-facing change here: things like `RUSTC_BOOTSTRAP=0` no
longer active nightly features. In practice this shouldn't be a big
deal, since `RUSTC_BOOTSTRAP` is the opposite of stable and everyone
uses `RUSTC_BOOTSTRAP=1` anyway.
- Add tests
Check against `Cheat`, not whether nightly features are allowed.
Nightly features are always allowed on the nightly channel.
- Only call `is_nightly_build()` once within a function
- Use booleans consistently for rustc_incremental
Sessions can't be passed through threads, so `read_file` couldn't take a
session. To be consistent, also take a boolean in `write_file_header`.
- Handle variants, fields, macros in `Node::ident()`
- Handle the crate root in `opt_item_name`
- Factor out `item_name_from_def_id` to reduce duplication
- Look at HIR before the DefId for `opt_item_name`
This gives accurate spans, which are not available from serialized
metadata.
- Don't panic on the crate root in `opt_item_name`
- Add comments
The inliner integrates call destination place with callee return place
by remapping the local and adding extra projections as necessary.
If a call destination place contains any projections (which is already
possible) and a return place is used in an indexing projection (most
likely doesn't happen yet) the end result would be incorrect.
Add an assertion to ensure that potential issue won't go unnoticed in
the presence of more sophisticated copy propagation scheme.
This wasn't necessary until MIR inliner started to consider drop glue as
a candidate for inlining; introducing for the first time a generic use
of size-of operation.
No test at this point since this only happens with a custom inlining
threshold.
The renumber pass is long gone
Originally, there has been a dedicated pass for renumbering
AST NodeIds to have actual values. This pass had been added by
commit a5ad4c3794.
Then, later, this step was moved to where it resides now,
macro expansion. See commit c86c8d41a2
or PR #36438.
The comment snippet, added by the original commit, has
survived the times without any change, becoming outdated
at removal of the dedicated pass.
Nowadays, grepping for the next_node_id function will show up
multiple places in the compiler that call it, but the main
rewriting that the comment talks about is still done in the
expansion step, inside an innocious looking visit_id function
that's called during macro invocation collection.
inliner: Copy unevaluated constants only after successful inlining
Inliner copies the unevaluated constants from the callee body to the
caller at the point where decision to inline is yet to be made. The
constants will be unnecessary if inlining were to fail.
Organize the code moving items from callee to the caller together in one
place to avoid the issue.
Fix unreachable sub-branch detection in or-patterns
The previous implementation was too eager to avoid unnecessary "unreachable pattern" warnings. I feel more confident about this implementation than I felt about the previous one.
Fixes https://github.com/rust-lang/rust/issues/76836.
``@rustbot`` modify labels: +A-exhaustiveness-checking
Working expression optimization, and some improvements to branch-level source coverage
This replaces PR #78040 after reorganizing the original commits (by request) into a more logical sequence of major changes.
Most of the work is in the MIR `transform/coverage/` directory (originally, `transform/instrument_coverage.rs`).
Note this PR includes some significant additional debugging capabilities, to help myself and any future developer working on coverage improvements or issues.
In particular, there's a new Graphviz (.dot file) output for the coverage graph (the `BasicCoverageBlock` control flow graph) that provides ways to get some very good insight into the relationships between the MIR, the coverage graph BCBs, coverage spans, and counters. (There are also some cool debugging options, available via environment variable, to alter how some data in the graph appears.)
And the code for this Graphviz view is actually generic... it can be used by any implementation of the Rust `Graph` traits.
Finally (for now), I also now output information from `llvm-cov` that shows the actual counters and spans it found in the coverage map, and their counts (from the `--debug` flag). I found this to be enormously helpful in debugging some coverage issues, so I kept it in the test results as well for additional context.
`@tmandry` `@wesleywiser`
r? `@tmandry`
Here's an example of the new coverage graph:
* Within each `BasicCoverageBlock` (BCB), you can see each `CoverageSpan` and its contributing statements (MIR `Statement`s and/or `Terminator`s)
* Each `CoverageSpan` has a `Counter` or and `Expression`, and `Expression`s show their Add/Subtract operation with nested operations. (This can be changed to show the Counter and Expression IDs instead, or in addition to, the BCB.)
* The terminators of all MIR `BasicBlock`s in the BCB, including one final `Terminator`
* If an "edge counter" is required (because we need to count an edge between blocks, in some cases) the edge's Counter or Expression is shown next to its label. (Not shown in the example below.) (FYI, Edge Counters are converted into a new MIR `BasicBlock` with `Goto`)
<img width="1116" alt="Screen Shot 2020-10-17 at 12 23 29 AM" src="https://user-images.githubusercontent.com/3827298/96331095-616cb480-100f-11eb-8212-60f2d433e2d8.png">
r? `@tmandry`
FYI: `@wesleywiser`
Implementing the Graph traits for the BasicCoverageBlock
graph.
optimized replacement of counters with expressions plus new BCB graphviz
* Avoid adding coverage to unreachable blocks.
* Special case for Goto at the end of the body. Make it non-reportable.
Improved debugging and formatting options (from env)
Don't automatically add counters to BCBs without CoverageSpans. They may
still get counters but only if there are dependencies from
other BCBs that have spans, I think.
Make CodeRegions optional for Counters too. It is
possible to inject counters (`llvm.instrprof.increment` intrinsic calls
without corresponding code regions in the coverage map. An expression
can still uses these counter values.
Refactored instrument_coverage.rs -> instrument_coverage/mod.rs, and
then broke up the mod into multiple files.
Compiling with coverage, with the expression optimization, works on
the json5format crate and its dependencies.
Refactored debug features from mod.rs to debug.rs
Originally, there has been a dedicated pass for renumbering
AST NodeIds to have actual values. This pass had been added by
commit a5ad4c3794.
Then, later, this step was moved to where it resides now,
macro expansion. See commit c86c8d41a2
or PR #36438.
The comment snippet, added by the original commit, has
survived the times without any change, becoming outdated
at removal of the dedicated pass.
Nowadays, grepping for the next_node_id function will show up
multiple places in the compiler that call it, but the main
rewriting that the comment talks about is still done in the
expansion step, inside an innocious looking visit_id function
that's called during macro invocation collection.
Changes from 68965 extended the kind of instances that are being
inlined. For some of those, the `instance_mir` returns a MIR body that
is already expressed in terms of the types found in substitution array,
and doesn't need further substitution.
Use `substs_for_mir_body` to take that into account.
The basic conversion is a straightforward conversion of the linear
recursion to a loop forwards and backwards propagation of the result.
But this uses an optimization to avoid the need for extra space that
would otherwise be necessary to store the stack of unfinished states as
the function is not tail recursive.
Observe that only non-root-nodes in cycles have a recursive call and
that every such call overwrites their own node state. Thus we reuse the
node state itself as temporary storage for the stack of unfinished
states by inverting the links to a chain back to the previous state
update. When we hit the root or end of the full explored chain we
propagate the node state update backwards by following the chain until
a node with a link to itself.
Previously, trying to allow this would give another error!
```
warning: unknown lint: `private_intra_doc_links`
--> private.rs:1:10
|
1 | #![allow(private_intra_doc_links)]
| ^^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `broken_intra_doc_links`
|
= note: `#[warn(unknown_lints)]` on by default
warning: public documentation for `DocMe` links to private item `DontDocMe`
--> private.rs:2:11
|
2 | /// docs [DontDocMe]
| ^^^^^^^^^ this item is private
|
= note: `#[warn(private_intra_doc_links)]` on by default
= note: this link will resolve properly if you pass `--document-private-items`
```
reverse binding order in matches to allow the subbinding of copyable fields in bindings after @
Fixes#69971
### TODO
- [x] Regression tests
r? `@oli-obk`
Inliner copies the unevaluated constants from the callee body to the
caller at the point where decision to inline is yet to be made. The
constants will be unnecessary if inlining were to fail.
Organize the code moving items from callee to the caller together in one
place to avoid the issue.
Provide diagnostic suggestion in ExprUseVisitor Delegate
The [Delegate trait](981346fc07/compiler/rustc_typeck/src/expr_use_visitor.rs (L28-L38)) currently use `PlaceWithHirId` which is composed of Hir `Place` and the
corresponding expression id.
Even though this is an accurate way of expressing how a Place is used,
it can cause confusion during diagnostics.
Eg:
```
let arr : [String; 5];
let [a, ...] = arr;
^^^ E1 ^^^ = ^^E2^^
```
Here `arr` is moved because of the binding created E1. However, when we
point to E1 in diagnostics with the message `arr` was moved, it can be
confusing. Rather we would like to report E2 to the user.
Closes: https://github.com/rust-lang/project-rfc-2229/issues/20
r? `@ghost`
Refactorings in preparation for const value trees
cc #72396
This PR changes the `Scalar::Bits { data: u128, size: u8 }` variant to `Scalar::Bits(ScalarInt)` where `ScalarInt` contains the same information, but is `repr(packed)`. The reason for using a packed struct is to allow enum variant packing to keep the original size of `Scalar` instead of adding another word to its size due to padding.
Other than that the PR just gets rid of all the inspection of the internal fields of `Scalar::Bits` which were frankly scary. These fields have invariants that we need to uphold and we can't do that without making the fields private.
r? `@ghost`
Use reparsed `TokenStream` if we captured any inner attributes
Fixes#78675
We now bail out of `prepend_attrs` if we ended up capturing any inner
attributes (which can happen in several places, due to token capturing
for `macro_rules!` arguments.
Hash both the length and the end location (line/column) of a span. If we
hash only the length, for example, then two otherwise equal spans with
different end locations will have the same hash. This can cause a
problem during incremental compilation wherein a previous result for a
query that depends on the end location of a span will be incorrectly
reused when the end location of the span it depends on has changed. A
similar analysis applies if some query depends specifically on the
length of the span, but we only hash the end location. So hash both.
Fix#46744, fix#59954, fix#63161, fix#73640, fix#73967, fix#74890, fix#75900
Corrected suggestion for generic parameters in `function_item_references` lint
This commit handles functions with generic type parameters like you pointed out as well as const generics. Also this is probably a minor thing, but the type alias you used in the example doesn't show up so the suggestion right now would be `size_of::<[u8; 16]> as fn() ->`. This is because the lint checker works with MIR instead of HIR. I don't think we can get the alias at that point, but let me know if I'm wrong and there's a way to fix this. Also I put you as the reviewer, but I'm not sure if you want to review it or if it makes more sense to ask one of the original reviewers of this lint.
closes#78571
Improve errors about #[deprecated] attribute
This change:
1. Turns `#[deprecated]` on a trait impl block into an error, which fixes#78625;
2. Changes these and other errors about `#[deprecated]` to use the span of the attribute instead of the item; and
3. Turns this error into a lint, to make sure it can be capped with `--cap-lints` and doesn't break any existing dependencies.
Can be reviewed per commit.
---
Example:
```rust
struct X;
#[deprecated = "a"]
impl Default for X {
#[deprecated = "b"]
fn default() -> Self {
X
}
}
```
Before:
```
error: This deprecation annotation is useless
--> src/main.rs:6:5
|
6 | / fn default() -> Self {
7 | | X
8 | | }
| |_____^
```
After:
```
error: this `#[deprecated]' annotation has no effect
--> src/main.rs:3:1
|
3 | #[deprecated = "a"]
| ^^^^^^^^^^^^^^^^^^^ help: try removing the deprecation attribute
|
= note: `#[deny(useless_deprecated)]` on by default
error: this `#[deprecated]' annotation has no effect
--> src/main.rs:5:5
|
5 | #[deprecated = "b"]
| ^^^^^^^^^^^^^^^^^^^ help: try removing the deprecation attribute
```
Add support for SHA256 source file hashing
Adds support for `-Z src-hash-algorithm sha256`, which became available in LLVM 11.
Using an older version of LLVM will cause an error `invalid checksum kind` if the hash algorithm is set to sha256.
r? `@eddyb`
cc #70401 `@est31`
Properly handle lint spans after MIR inlining
The first commit shows what happens when we apply mir inlining and then cause lints on the inlined MIR.
The second commit fixes that.
r? `@wesleywiser`
Retagging: do not retag 'raw reborrows'
When doing `&raw const (*raw_ptr).field`, we do not want any retagging; the original provenance should be fully preserved.
Fixes https://github.com/rust-lang/miri/issues/1608
Test added by https://github.com/rust-lang/miri/pull/1614
Not sure whom to ask for review on this... `@oli-obk` can you have a look? Or maybe highfive makes a good choice.^^
This is helpful when looking for CGUs where the size estimate isn't a
good indicator of compilation time.
I verified that moving the profiling timer call doesn't affect the
results.
add mipsel-unknown-none target
This adds a target for bare MIPS32r2, little endian, softfloat. This target can be used for PIC32 microcontrollers (or possibly for other devices that have a MIPS MCU core such as the M4K core).
Tried to find a name for the target that is in line with the naming scheme apparently used for the other MIPS targets.
r? `@jonas-schievink`
Fix ICE when a future-incompat-report has its command-line level capped
Fixes#78660
With PR https://github.com/rust-lang/rust/pull/75534 merged, we now run
more lint-related code for future-incompat-report, even when their final
level is Allow. Some lint-related code was not expecting `Level::Allow`,
and had an explicit panic.
This PR explicitly tracks the lint level set on the command line before
`--cap-lints` is applied. This is used to emit a more precise error
note (e.g. we don't say that `-W lint-name` was specified on the
command line just because a lint was capped to Warn). As a result, we
can now correctly emit a note that `-A` was used if we got
`Level::Allow` from the command line (before the cap is applied).
Treat trailing semicolon as a statement in macro call
See #61733 (comment)
We now preserve the trailing semicolon in a macro invocation, even if
the macro expands to nothing. As a result, the following code no longer
compiles:
```rust
macro_rules! empty {
() => { }
}
fn foo() -> bool { //~ ERROR mismatched
{ true } //~ ERROR mismatched
empty!();
}
```
Previously, `{ true }` would be considered the trailing expression, even
though there's a semicolon in `empty!();`
This makes macro expansion more token-based.
foreign_modules query hash table lookups
When compiling a large monolithic crate we're seeing huge times in the `foreign_modules` query due to repeated iteration over foreign modules (in order to find a module by its id). This implements hash table lookups so that which massively reduces time spent in that query in this particular case. We'll need to see if the overhead of creating the hash table has a negative impact on performance in more normal compilation scenarios.
I'm working with `@wesleywiser` on this.
Fixes#78675
We now bail out of `prepend_attrs` if we ended up capturing any inner
attributes (which can happen in several places, due to token capturing
for `macro_rules!` arguments.
See https://github.com/rust-lang/rust/issues/61733#issuecomment-716188981
We now preserve the trailing semicolon in a macro invocation, even if
the macro expands to nothing. As a result, the following code no longer
compiles:
```rust
macro_rules! empty {
() => { }
}
fn foo() -> bool { //~ ERROR mismatched
{ true } //~ ERROR mismatched
empty!();
}
```
Previously, `{ true }` would be considered the trailing expression, even
though there's a semicolon in `empty!();`
This makes macro expansion more token-based.
Transform post order walk to an iterative approach
The previous recursive approach might overflow the stack when walking a
particularly deep, list-like, graph. In particular, dominator
calculation for borrow checking does such a traversal and very long
functions might lead to a region dependency graph with in this
problematic structure.
This addresses what appears to be the cause of #78567 (`@SunHao-0` thanks for the stack trace).
Rollup of 5 pull requests
Successful merges:
- #78606 (Clarify handling of final line ending in str::lines())
- #78610 (Do not remove tokens before AST json serialization)
- #78620 (Trivial fixes to bitwise operator documentation)
- #78627 (Point out that total_cmp is no strict superset of partial comparison)
- #78637 (Add fetch_update methods to AtomicBool and AtomicPtr)
Failed merges:
r? `@ghost`
Fixes#78660
With PR https://github.com/rust-lang/rust/pull/75534 merged, we now run
more lint-related code for future-incompat-report, even when their final
level is Allow. Some lint-related code was not expecting `Level::Allow`,
and had an explicit panic.
This PR explicitly tracks the lint level set on the command line before
`--cap-lints` is applied. This is used to emit a more precise error
note (e.g. we don't say that `-W lint-name` was specified on the
command line just because a lint was capped to Warn). As a result, we
can now correctly emit a note that `-A` was used if we got
`Level::Allow` from the command line (before the cap is applied).
The [Delegate
trait](981346fc07/compiler/rustc_typeck/src/expr_use_visitor.rs (L28-L38))
currently use `PlaceWithHirId` which is composed of Hir `Place` and the
corresponding expression id.
Even though this is an accurate way of expressing how a Place is used,
it can cause confusion during diagnostics.
Eg:
```
let arr : [String; 5];
let [a, ...] = arr;
^^^ E1 ^^^ = ^^E2^^
```
Here `arr` is moved because of the binding created E1. However, when we
point to E1 in diagnostics with the message `arr` was moved, it can be
confusing. Rather we would like to report E2 to the user.
Closes: https://github.com/rust-lang/project-rfc-2229/issues/20
Do not remove tokens before AST json serialization
`TokenStripper` is error-prone and introduces one more use of `MutVisitor`.
It's much simpler to treat serialization as just one more place that wants lazy token stream to turn into a real token stream.
Also, no code is better than more code, in general.
r? @Aaron1011
(I also merged tests for `TokenStripper` ICEs into one.)
Add option to customize the nll-facts' folder location
This PR adds a `nll-facts-dir` option to specify the location of the directory in which NLL facts are dumped into. It works the same way `dump-mir-dir` controls the location used by the `dump-mir` option.
This lint was incorrectly suggesting casting a function to a pointer without
specifying generic type parameters or const generics. This would cause a
compiler error since the missing parameters couldn't be inferred. This commit
fixed the suggestion and added a few tests with generics.
Implement -Z relax-elf-relocations=yes|no
This lets rustc users tweak whether the linker should relax ELF relocations without recompiling a whole new target with its own libcore etc.
Implement rustc side of report-future-incompat
cc https://github.com/rust-lang/rust/issues/71249
This is an alternative to `@pnkfelix's` initial implementation in https://github.com/pnkfelix/rust/commits/prototype-rustc-side-of-report-future-incompat (mainly because I started working before seeing that branch 😄 ).
My approach outputs the entire original `Diagnostic`, in a way that is compatible with incremental compilation. This is not yet integrated with compiletest, but can be used manually by passing `-Z emit-future-incompat-report` to `rustc`.
Several changes are made to support this feature:
* The `librustc_session/lint` module is moved to a new crate `librustc_lint_defs` (name bikesheddable). This allows accessing lint definitions from `librustc_errors`.
* The `Lint` struct is extended with an `Option<FutureBreakage>`. When present, it indicates that we should display a lint in the future-compat report. `FutureBreakage` contains additional information that we may want to display in the report (currently, a `date` field indicating when the crate will stop compiling).
* A new variant `rustc_error::Level::Allow` is added. This is used when constructing a diagnostic for a future-breakage lint that is marked as allowed (via `#[allow]` or `--cap-lints`). This allows us to capture any future-breakage diagnostics in one place, while still discarding them before they are passed to the `Emitter`.
* `DiagnosticId::Lint` is extended with a `has_future_breakage` field, indicating whether or not the `Lint` has future breakage information (and should therefore show up in the report).
* `Session` is given access to the `LintStore` via a new `SessionLintStore` trait (since `librustc_session` cannot directly reference `LintStore` without a cyclic dependency). We use this to turn a string `DiagnosticId::Lint` back into a `Lint`, to retrieve the `FutureBreakage` data.
Currently, `FutureBreakage.date` is always set to `None`. However, this could potentially be interpreted by Cargo in the future.
I've enabled the future-breakage report for the `ARRAY_INTO_ITER` lint, which can be used to test out this PR. The intent is to use the field to allow Cargo to determine the date of future breakage (as described in [RFC 2834](https://github.com/rust-lang/rfcs/blob/master/text/2834-cargo-report-future-incompat.md)) without needing to parse the diagnostic itself.
cc `@pnkfelix`
Fix#78549
Before #78430, this worked because `specialize_constructor` didn't actually care too much which constructor was passed to it unless needed. That PR however handles `&str` as a special case, and I did not anticipate patterns for the `&str` type other than string literals.
I am not very confident there are not other similar oversights left, but hopefully only `&str` was different enough to break my assumptions.
Fixes https://github.com/rust-lang/rust/issues/78549
Rollup of 6 pull requests
Successful merges:
- #78073 (Add #[inline] to some functions in core::str.)
- #78596 (Fix doc links to std::fmt)
- #78599 (Add note to process::arg[s] that args shouldn't be escaped or quoted)
- #78602 (fix various aliasing issues in the standard library)
- #78603 (expand: Tweak a comment in implementation of `macro_rules`)
- #78621 (Inline Default::default() for atomics)
Failed merges:
r? `@ghost`
