I know very little about rust, so I saw this example and tried to generalize it by writing,
```
let layout = Layout:🆕:<T>();
let new_obj = unsafe {
let ptr = alloc(layout) as *mut T;
*ptr = obj;
Box::from_raw(ptr)
};
```
for some more complicated `T`, which ended up crashing with SIGSEGV,
because it tried to `drop_in_place` the previous object in `ptr` which is
of course garbage. I also added a comment that explains why `.write`
is used, but I think adding that comment is optional and may be too verbose
here. I do however think that changing this example is a good idea to
suggest the correct generalization. `.write` is also used in most of the rest
of the documentation here, even if the example is `i32`, so it would additionally
be more consistent.
Always capture tokens for `macro_rules!` arguments
When we invoke a proc-macro, the `TokenStream` we pass to it may contain 'interpolated' AST fragments, represented by `rustc_ast::token::Nonterminal`. In order to correctly, pass a `Nonterminal` to a proc-macro, we need to have 'captured' its `TokenStream` at the time the AST was parsed.
Currently, we perform this capturing when attributes are present on items and expressions, since we will end up using a `Nonterminal` to pass the item/expr to any proc-macro attributes it is annotated with. However, `Nonterminal`s are also introduced by the expansion of metavariables in `macro_rules!` macros. Since these metavariables may be passed to proc-macros, we need to have tokens available to avoid the need to pretty-print and reparse (see https://github.com/rust-lang/rust/issues/43081).
This PR unconditionally performs token capturing for AST items and expressions that are passed to a `macro_rules!` invocation. We cannot know in advance if captured item/expr will be passed to proc-macro, so this is needed to ensure that tokens will always be available when they are needed.
This ensures that proc-macros will receive tokens with proper `Spans` (both location and hygiene) in more cases. Like all work on https://github.com/rust-lang/rust/issues/43081, this will cause regressions in proc-macros that were relying on receiving tokens with dummy spans.
In this case, Crater revealed only one regression: the [Pear](https://github.com/SergioBenitez/Pear) crate (a helper for [rocket](https://github.com/SergioBenitez/Rocket)), which was previously [fixed](https://github.com/SergioBenitez/Pear/pull/25) as part of https://github.com/rust-lang/rust/pull/73084.
This regression manifests itself as the following error:
```
[INFO] [stdout] error: proc macro panicked
[INFO] [stdout] --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/rocket_http-0.4.5/src/parse/uri/parser.rs:119:34
[INFO] [stdout] |
[INFO] [stdout] 119 | let path_and_query = pear_try!(path_and_query(is_pchar));
[INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] |
[INFO] [stdout] = help: message: called `Option::unwrap()` on a `None` value
[INFO] [stdout] = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
```
It can be fixed by running `cargo update -p pear`, which updates your `Cargo.lock` to use the latest version of Pear (which includes a bugfix for the regression).
Split out from https://github.com/rust-lang/rust/pull/73084/
rustc: Modernize wasm checks for atomics
This commit modernizes how rustc checks for whether the `atomics`
feature is enabled for the wasm target. The `sess.target_features` set
is consulted instead of fiddling around with dealing with various
aspects of LLVM and that syntax.
The const propagator cannot trace references.
Thus we avoid propagation of a local the moment we encounter references to it.
fixes#73609
cc @RalfJung
r? @wesleywiser
Point at the call span when overflow occurs during monomorphization
This improves the output for issue #72577, but there's still more work
to be done.
Currently, an overflow error during monomorphization results in an error
that points at the function we were unable to monomorphize. However, we
don't point at the call that caused the monomorphization to happen. In
the overflow occurs in a large recursive function, it may be difficult
to determine where the issue is.
This commit tracks and `Span` information during collection of
`MonoItem`s, which is used when emitting an overflow error. `MonoItem`
itself is unchanged, so this only affects
`src/librustc_mir/monomorphize/collector.rs`
Move remaining `NodeId` APIs from `Definitions` to `Resolver`
Implements https://github.com/rust-lang/rust/pull/73291#issuecomment-643515557
TL;DR: it moves all fields that are only needed during name resolution passes into the `Resolver` and keep the rest in `Definitions`. This effectively enforces that all references to `NodeId`s are gone once HIR lowering is completed.
After this, the only remaining work for #50928 should be to adjust the dev guide.
r? @petrochenkov
Fix -Z unpretty=everybody_loops
It turns out that this has not been working for who knows how long.
Previously:
```
pub fn h() { 1 + 2; }
```
After this change:
```
pub fn h() { loop { } }
```
This only affected the pass when run with the command line
pretty-printing option, so rustdoc was still replacing bodies with
`loop {}`.
code coverage foundation for hash and num_counters
This PR is the next iteration after PR #73011 (which is still waiting on bors to merge).
@wesleywiser - PTAL
r? @tmandry
(FYI, I'm also working on injecting the coverage maps, in another branch, while waiting for these to merge.)
Thanks!
Check for assignments between non-conflicting generator saved locals
This is to prevent future changes to the generator transform from reintroducing the problem that caused #73137. Namely, a store between two generator saved locals whose storage does not conflict.
My ultimate goal is to introduce a modified version of #71956 that handles this case properly.
r? @tmandry
Mention that BTreeMap::new() doesn't allocate
I think it would be nice to mention this, so you don't have to dig through the src to look at the definition of new().
rustdoc: Fix doc aliases with crate filtering
Fix a crash when searching for an alias contained in the currently selected filter crate.
Also remove alias search results for crates that should be filtered out.
The test suite needed to be fixed to actually take into account the crate filtering and check that there are no results when none are expected.
Needs to be backported to beta to fix the `std` docs.
Fixes#73620
r? @GuillaumeGomez
This commit modernizes how rustc checks for whether the `atomics`
feature is enabled for the wasm target. The `sess.target_features` set
is consulted instead of fiddling around with dealing with various
aspects of LLVM and that syntax.
Context: this is needed to fix https://github.com/rust-lang/rustfmt/issues/4263,
which currently records the span of a const generic param incorrectly
because the location of the `const` kw is not known.
I am not sure how to add tests for this; any guidance in how to do so
would be appreciated 🙂
This commit updates rustc's LLVM submodule to include new AVR-specific
fixes recently merged on the Rust LLVM 'rustc/10.0-2020-05-05' branch.
All of these cherry-picked commits exist in upstream LLVM and were
cherry-picked into Rust's LLVM fork in commit 6c040dd86ed.
|- 6c040dd86ed Merge pull request #66 from dylanmckay/avr-pick-upstream-llvm-fixes
|- 12dfdd3aed7 [AVR] Rewrite the function calling convention.
|- 118ac53f12b [AVR] Don't adjust for instruction size
|- bc27c282e13 [AVR] Fix miscompilation of zext + add
|- cfbe205a7e8 [AVR] Remove faulty stack pushing behavior
|- 143e1469e96 [AVR] Fix stack size in functions with a frame pointer
|- 6b2445d841e [LLVM][AVR] Support for R_AVR_6 fixup
|- 93ee4da19cf [AVR] Fix I/O instructions on XMEGA
|- 962c2415ffb [AVR] Do not place functions in .progmem.data
|- 65b8b170aef [AVR] Do not use divmod calls for bigger integers
|- 93a3b595d1c [AVR] Generalize the previous interrupt bugfix to signal
|- handlers too
|- cc4286349b4 [AVR] Respect the 'interrupt' function attribute
|- 954d0a92205 [AVR] Fix reads of uninitialized variables from constructor of AVRSubtarget
|- 1c0ddae73c9 [AVR] Fix read of uninitialized variable AVRSubtarget:::ELFArch
|- 0ed0823fe60 [AVR] Fix incorrect register state for LDRdPtr
|- 96075fc433d [AVR] Don't adjust addresses by 2 for absolute values
|- 6dfc55ba53b [AVR] Use correct register class for mul instructions
These changes include both correctness fixes and LLVM assertion error
fixes. Once all of these commits have been cherry-picked, all of the
LLVM plumbing for rust-lang/master to compile the AVR blink program will
be in place. Once this commit is merged, only PR rust-lang/rust#73270 will
be blocking successful compilation and emission of the AVR LED blink program.
Downgrade unnested_or_patterns to pedantic
Even with #5704 fixed, I don't believe it is a safe bet that if someone is using or-patterns anywhere in a codebase then they want to use it as much as possible in the whole codebase. I think it would be reasonable to reevaluate after the feature is stable. I feel that a warn-by-default lint suggesting use of an unstable feature, even if already being used in one place, is questionable.
changelog: Remove unnested_or_patterns from default set of enabled lints
In the following example, an inaccessible path is suggested via
`use foo::bar::X;` whereas an accessible public exported path can
be suggested instead.
```
mod foo {
mod bar {
pub struct X;
}
pub use self::bar::X;
}
fn main() { X; }
```
This fixes the issue.
Fix a crash when searching for an alias contained in the currently selected filter crate.
Also remove alias search results for crates that should be filtered out.
The test suite needed to be fixed to actually take into account the crate filtering and check that there are no results when none are expected.
