Render more readable macro matcher tokens in rustdoc
Follow-up to #92334.
This PR lifts some of the token rendering logic from https://github.com/dtolnay/prettyplease into rustdoc so that even the matchers for which a source code snippet is not available (because they are macro-generated, or any other reason) follow some baseline good assumptions about where the tokens in the macro matcher are appropriate to space.
The below screenshots show an example of the difference using one of the gnarliest macros I could find. Some things to notice:
- In the **before**, notice how a couple places break in between `$(....)`↵`*`, which is just about the worst possible place that it could break.
- In the **before**, the lines that wrapped are weirdly indented by 1 space of indentation relative to column 0. In the **after**, we use the typical way of block indenting in Rust syntax which is put the open/close delimiters on their own line and indent their contents by 4 spaces relative to the previous line (so 8 spaces relative to column 0, because the matcher itself is indented by 4 relative to the `macro_rules` header).
- In the **after**, macro_rules metavariables like `$tokens:tt` are kept together, which is how just about everybody writing Rust today writes them.
## Before
![Screenshot from 2022-01-14 13-05-53](https://user-images.githubusercontent.com/1940490/149585105-1f182b78-751f-421f-a234-9dbc04fa3bbd.png)
## After
![Screenshot from 2022-01-14 13-06-04](https://user-images.githubusercontent.com/1940490/149585118-d4b52ea7-3e67-4b6e-a12b-31dfb8172f86.png)
r? `@camelid`
Rename _args -> args in format_args expansion
As observed in https://github.com/rust-lang/rust/pull/91359#discussion_r786058960, prior to that PR this variable was sometimes never used, such as in the case of:
```rust
println!("");
// used to expand to:
::std::io::_print(
::core::fmt::Arguments::new_v1(
&["\n"],
&match () {
_args => [],
},
),
);
```
so the leading underscore in `_args` was used to suppress an unused variable lint. However after #91359 the variable is always used when present, as the unused case would instead expand to:
```rust
::std::io::_print(::core::fmt::Arguments::new_v1(&["\n"], &[]));
```
Add note suggesting that predicate may be satisfied, but is not `const`
Not sure if we should be printing this in addition to, or perhaps _instead_ of the help message:
```
help: the trait `~const Add` is not implemented for `NonConstAdd`
```
Also added `ParamEnv::is_const` and `PolyTraitPredicate::is_const_if_const` and, in a separate commit, used those in other places instead of `== hir::Constness::Const`, etc.
r? ````@fee1-dead````
remove unused `jemallocator` crate
When it was noticed that the rustc binary wasn't actually using jemalloc via `#[global_allocator]` and that was removed, the dependency remained.
Tests pass locally with a `jemalloc = true` build, but I'll trigger a try build to ensure I haven't missed an edge-case somewhere.
r? ```@ghost``` until that completes
Add `intrinsics::const_deallocate`
Tracking issue: #79597
Related: #91884
This allows deallocation of a memory allocated by `intrinsics::const_allocate`. At the moment, this can be only used to reduce memory usage, but in the future this may be useful to detect memory leaks (If an allocated memory remains after evaluation, raise an error...?).
Rollup of 10 pull requests
Successful merges:
- #92611 (Add links to the reference and rust by example for asm! docs and lints)
- #93158 (wasi: implement `sock_accept` and enable networking)
- #93239 (Add os::unix::net::SocketAddr::from_path)
- #93261 (Some unwinding related cg_ssa cleanups)
- #93295 (Avoid double panics when using `TempDir` in tests)
- #93353 (Unimpl {Add,Sub,Mul,Div,Rem,BitXor,BitOr,BitAnd}<$t> for Saturating<$t>)
- #93356 (Edit docs introduction for `std::cmp::PartialOrd`)
- #93375 (fix typo `documenation`)
- #93399 (rustbuild: Fix compiletest warning when building outside of root.)
- #93404 (Fix a typo from #92899)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add links to the reference and rust by example for asm! docs and lints
These were previously removed in #91728 due to broken links.
cc ``@ehuss`` since this updates the rust-by-example submodule
Fix debuginfo for pointers/references to unsized types
This PR makes the compiler emit fat pointer debuginfo in all cases. Before, we sometimes got thin-pointer debuginfo, making it impossible to fully interpret the pointed to memory in debuggers. The code is actually cleaner now, especially around generation of trait object pointer debuginfo.
Fixes https://github.com/rust-lang/rust/issues/92718
~~Blocked on https://github.com/rust-lang/rust/pull/92729.~~
Suggest tuple-parentheses for enum variants
This follows on from #86493 / #86481, making the parentheses suggestion. To summarise, given the following code:
```rust
fn f() -> Option<(i32, i8)> {
Some(1, 2)
}
```
The current output is:
```
error[E0061]: this enum variant takes 1 argument but 2 arguments were supplied
--> b.rs:2:5
|
2 | Some(1, 2)
| ^^^^ - - supplied 2 arguments
| |
| expected 1 argument
error: aborting due to previous error
For more information about this error, try `rustc --explain E0061`.
```
With this change, `rustc` will now suggest parentheses when:
- The callee is expecting a single tuple argument
- The number of arguments passed matches the element count in the above tuple
- The arguments' types match the tuple's fields
```
error[E0061]: this enum variant takes 1 argument but 2 arguments were supplied
--> b.rs:2:5
|
2 | Some(1, 2)
| ^^^^ - - supplied 2 arguments
|
help: use parentheses to construct a tuple
|
2 | Some((1, 2))
| + +
```
LLDB does not seem to see fields if they are marked with DW_AT_artificial
which breaks pretty printers that use these fields for decoding fat pointers.
Only traverse attrs once while checking for coherence override attributes
In coherence, while checking for negative impls override attributes: only traverse the `DefId`s' attributes once.
This PR is an easy way to get back some of the small perf loss in #93175
Clarify the `usage-of-qualified-ty` error message.
I found this message confusing when I encountered it. This commit makes
it clearer that you have to import the unqualified type yourself.
r? `@lcnr`
Introduce a limit to Levenshtein distance computation
Incorporate distance limit from `find_best_match_for_name` directly into
Levenshtein distance computation.
Use the string size difference as a lower bound on the distance and exit
early when it exceeds the specified limit.
After finding a candidate within a limit, lower the limit further to
restrict the search space.
Add test for stable hash uniqueness of adjacent field values
This PR adds a simple test to check that stable hash will produce a different hash if the order of two values that have the same combined bit pattern changes.
r? `@the8472`
It's simply a binary thing to allow different behaviour for `Copy` vs
`!Copy` types. The new code makes this much clearer; I was scratching my
head over the old code for some time.
If hir_owner is Owner(_), the LocalDefId is pointing to an owner, so the ItemLocalId is 0.
If the HIR node does not exist, we store Phantom.
Otherwise, we store the HirId associated to the LocalDefId.
Ignore unwinding edges when checking for unconditional recursion
The unconditional recursion lint determines if all execution paths
eventually lead to a self-recursive call.
The implementation always follows unwinding edges which limits its
practical utility. For example, it would not lint function `f` because a
call to `g` might unwind. It also wouldn't lint function `h` because an
overflow check preceding the self-recursive call might unwind:
```rust
pub fn f() {
g();
f();
}
pub fn g() { /* ... */ }
pub fn h(a: usize) {
h(a + 1);
}
```
To avoid the issue, assume that terminators that might continue
execution along non-unwinding edges do so.
Fixes#78474.
The unconditional recursion lint determines if all execution paths
eventually lead to a self-recursive call.
The implementation always follows unwinding edges which limits its
practical utility. For example, it would not lint function `f` because a
call to `g` might unwind. It also wouldn't lint function `h` because an
overflow check preceding the self-recursive call might unwind:
```rust
pub fn f() {
g();
f();
}
pub fn g() { /* ... */ }
pub fn h(a: usize) {
h(a + 1);
}
```
To avoid the issue, assume that terminators that might continue
execution along non-unwinding edges do so.
Fix the unsoundness in the `early_otherwise_branch` mir opt pass
Closes#78496 .
This change is a significant rewrite of much of the pass. Exactly what it does is documented in the source file (with ascii art!), and all the changes that are made to the MIR that are not trivially sound are carefully documented. That being said, this is my first time touching MIR, so there are probably some invariants I did not know about that I broke.
This version of the optimization is also somewhat more flexible than the original; for example, we do not care how or where the value on which the parent is switching is computed. There is no requirement that any types be the same. This could be made even more flexible in the future by allowing a wider range of statements in the bodies of `BBC, BBD` (as long as they are all the same of course). This should be a good first step though.
Probably needs a perf run.
r? `@oli-obk` who reviewed things the last time this was touched
Incorporate distance limit from `find_best_match_for_name` directly into
Levenshtein distance computation.
Use the string size difference as a lower bound on the distance and exit
early when it exceeds the specified limit.
After finding a candidate within a limit, lower the limit further to
restrict the search space.
rustdoc: Pre-calculate traits that are in scope for doc links
This eliminates one more late use of resolver (part of #83761).
At early doc link resolution time we go through parent modules of items from the current crate, reexports of items from other crates, trait items, and impl items collected by `collect-intra-doc-links` pass, determine traits that are in scope in each such module, and put those traits into a map used by later rustdoc passes.
r? `@jyn514`
Fix ICE when parsing bad turbofish with lifetime argument
Generalize conditions where we suggest adding the turbofish operator, so we don't ICE during code like
```rust
fn foo() {
A<'a,>
}
```
but instead suggest adding a turbofish.
Fixes#93282
Remove deduplication of early lints
We already have a general mechanism for deduplicating reported
lints, so there's no need to have an additional one for early lints
specifically. This allows us to remove some `PartialEq` impls.
Store a `Symbol` instead of an `Ident` in `AssocItem`
This is the same idea as #92533, but for `AssocItem` instead
of `VariantDef`/`FieldDef`.
With this change, we no longer have any uses of
`#[stable_hasher(project(...))]`
Remove ordering traits from `OutlivesConstraint`
In two cases where this ordering was used, I've replaced the sorting to use a key that does not rely on `DefId` being `Ord`. This is part of #90317. If I understand correctly, whether this is correct depends on whether the `RegionVid`s are tracked during incremental compilation. But I might be mistaken in this approach. cc `@cjgillot`
Use error-on-mismatch policy for PAuth module flags.
This agrees with Clang, and avoids an error when using LTO with mixed
C/Rust. LLVM considers different behaviour flags to be a mismatch,
even when the flag value itself is the same.
This also makes the flag setting explicit for all uses of
LLVMRustAddModuleFlag.
----
I believe that this fixes#92885, but have only reproduced it locally on Linux hosts so cannot confirm that it fixes the issue as reported.
I have not included a test for this because it is covered by an existing test (`src/test/run-make-fulldeps/cross-lang-lto-clang`). It is not without its problems, though:
* The test requires Clang and `--run-clang-based-tests-with=...` to run, and this is not the case on the CI.
* Any test I add would have a similar requirement.
* With this patch applied, the test gets further, but it still fails (for other reasons). I don't think that affects #92885.
Work around missing code coverage data causing llvm-cov failures
If we do not add code coverage instrumentation to the `Body` of a
function, then when we go to generate the function record for it, we
won't write any data and this later causes llvm-cov to fail when
processing data for the entire coverage report.
I've identified two main cases where we do not currently add code
coverage instrumentation to the `Body` of a function:
1. If the function has a single `BasicBlock` and it ends with a
`TerminatorKind::Unreachable`.
2. If the function is created using a proc macro of some kind.
For case 1, this is typically not important as this most often occurs as
a result of function definitions that take or return uninhabited
types. These kinds of functions, by definition, cannot even be called so
they logically should not be counted in code coverage statistics.
For case 2, I haven't looked into this very much but I've noticed while
testing this patch that (other than functions which are covered by case
1) the skipped function coverage debug message is occasionally triggered
in large crate graphs by functions generated from a proc macro. This may
have something to do with weird spans being generated by the proc macro
but this is just a guess.
I think it's reasonable to land this change since currently, we fail to
generate *any* results from llvm-cov when a function has no coverage
instrumentation applied to it. With this change, we get coverage data
for all functions other than the two cases discussed above.
Fixes#93054 which occurs because of uncallable functions which shouldn't
have code coverage anyway.
I will open an issue for missing code coverage of proc macro generated
functions and leave a link here once I have a more minimal repro.
r? ``@tmandry``
cc ``@richkadel``
Move param count error emission to end of `check_argument_types`
The error emission here isn't exactly what is done in #92364, but replicating that is hard . The general move should make for a smaller diff.
Also included the `(usize, Ty, Ty)` to -> `Option<(Ty, Ty)>` commit.
r? ``@estebank``
Properly track `DepNode`s in trait evaluation provisional cache
Fixes#92987
During evaluation of an auto trait predicate, we may encounter a cycle.
This causes us to store the evaluation result in a special 'provisional
cache;. If we later end up determining that the type can legitimately
implement the auto trait despite the cycle, we remove the entry from
the provisional cache, and insert it into the evaluation cache.
Additionally, trait evaluation creates a special anonymous `DepNode`.
All queries invoked during the predicate evaluation are added as
outoging dependency edges from the `DepNode`. This `DepNode` is then
store in the evaluation cache - if a different query ends up reading
from the cache entry, it will also perform a read of the stored
`DepNode`. As a result, the cached evaluation will still end up
(transitively) incurring all of the same dependencies that it would
if it actually performed the uncached evaluation (e.g. a call to
`type_of` to determine constituent types).
Previously, we did not correctly handle the interaction between the
provisional cache and the created `DepNode`. Storing an evaluation
result in the provisional cache would cause us to lose the `DepNode`
created during the evaluation. If we later moved the entry from the
provisional cache to the evaluation cache, we would use the `DepNode`
associated with the evaluation that caused us to 'complete' the cycle,
not the evaluatoon where we first discovered the cycle. As a result,
future reads from the evaluation cache would miss some incremental
compilation dependencies that would have otherwise been added if the
evaluation was *not* cached.
Under the right circumstances, this could lead to us trying to force
a query with a no-longer-existing `DefPathHash`, since we were missing
the (red) dependency edge that would have caused us to bail out before
attempting forcing.
This commit makes the provisional cache store the `DepNode` create
during the provisional evaluation. When we move an entry from the
provisional cache to the evaluation cache, we create a *new* `DepNode`
that has dependencies going to *both* of the evaluation `DepNodes` we
have available. This ensures that cached reads will incur all of
the necessary dependency edges.
The previous PR, #93165, still performed the drop range analysis
despite ignoring the results. Unfortunately, there were ICEs in
the analysis as well, so some packages failed to build (see the
issue #93197 for an example). This change further disables the
analysis and just provides dummy results in that case.
This agrees with Clang, and avoids an error when using LTO with mixed
C/Rust. LLVM considers different behaviour flags to be a mismatch,
even when the flag value itself is the same.
This also makes the flag setting explicit for all uses of
LLVMRustAddModuleFlag.
Revert "Do not hash leading zero bytes of i64 numbers in Sip128 hasher"
Reverts rust-lang/rust#92103. It had a (in retrospect, obvious) correctness problem where changing the order of two adjacent values would produce identical hashes, which is problematic in stable hashing (see [this comment](https://github.com/rust-lang/rust/pull/92103#issuecomment-1014625442)).
I'll try to send the PR again with a fix for this issue.
r? `@the8472`
Check `const Drop` impls considering `~const` Bounds
This PR adds logic to trait selection to account for `~const` bounds in custom `impl const Drop` for types, elaborates the `const Drop` check in `rustc_const_eval` to check those bounds, and steals some drop linting fixes from #92922, thanks `@DrMeepster.`
r? `@fee1-dead` `@oli-obk` <sup>(edit: guess I can't request review from two people, lol)</sup>
since each of you wrote and reviewed #88558, respectively.
Since the logic here is more complicated than what existed, it's possible that this is a perf regression. But it works correctly with tests, and that makes me happy.
Fixes#92881
We already have a general mechanism for deduplicating reported
lints, so there's no need to have an additional one for early lints
specifically. This allows us to remove some `PartialEq` impls.