Adding compile fail test for staged_api feature
Issue #39059
r? @est31
@est31 running the tests for this feature fails. Is that expected since this is the `compile-fail`suite?
I copied this test from the run-pass suite: `rust/src/test/run-pass/reachable-unnameable-type-alias.rs`. What are the differences between these suites in operation and why they are used?
[MIR] SwitchInt Everywhere
Something I've been meaning to do for a very long while. This PR essentially gets rid of 3 kinds of conditional branching and only keeps the most general one - `SwitchInt`. Primary benefits are such that dealing with MIR now does not involve dealing with 3 different ways to do conditional control flow. On the other hand, constructing a `SwitchInt` currently requires more code than what previously was necessary to build an equivalent `If` terminator. Something trivially "fixable" with some constructor methods somewhere (MIR needs stuff like that badly in general).
Some timings (tl;dr: slightly faster^1 (unexpected), but also uses slightly more memory at peak (expected)):
^1: Not sure if the speed benefits are because of LLVM liking the generated code better or the compiler itself getting compiled better. Either way, its a net benefit. The CORE and SYNTAX timings done for compilation without optimisation.
```
AFTER:
Building stage1 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
Finished release [optimized] target(s) in 31.50 secs
Finished release [optimized] target(s) in 31.42 secs
Building stage1 compiler artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
Finished release [optimized] target(s) in 439.56 secs
Finished release [optimized] target(s) in 435.15 secs
CORE: 99% (24.81 real, 0.13 kernel, 24.57 user); 358536k resident
CORE: 99% (24.56 real, 0.15 kernel, 24.36 user); 359168k resident
SYNTAX: 99% (49.98 real, 0.48 kernel, 49.42 user); 653416k resident
SYNTAX: 99% (50.07 real, 0.58 kernel, 49.43 user); 653604k resident
BEFORE:
Building stage1 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
Finished release [optimized] target(s) in 31.84 secs
Building stage1 compiler artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
Finished release [optimized] target(s) in 451.17 secs
CORE: 99% (24.66 real, 0.20 kernel, 24.38 user); 351096k resident
CORE: 99% (24.36 real, 0.17 kernel, 24.18 user); 352284k resident
SYNTAX: 99% (52.24 real, 0.56 kernel, 51.66 user); 645544k resident
SYNTAX: 99% (51.55 real, 0.48 kernel, 50.99 user); 646428k resident
```
cc @nikomatsakis @eddyb
macros: fix inert attributes from `proc_macro_derives` with `#![feature(proc_macro)]`
This PR refactors collection of `proc_macro_derive` invocations to fix#39347.
After this PR, the input to a `#[proc_macro_derive]` function no longer sees `#[derive]`s on the underlying item. For example, consider:
```rust
extern crate my_derives;
use my_derives::{Trait, Trait2};
#[derive(Copy, Clone)]
#[derive(Trait)]
#[derive(Trait2)]
struct S;
```
Today, the input to the `Trait` derive is `#[derive(Copy, Clone, Trait2)] struct S;`, and the input to the `Trait2` derive is `#[derive(Copy, Clone)] struct S;`. More generally, a `proc_macro_derive` sees all builtin derives, as well as all `proc_macro_derive`s listed *after* the one being invoked.
After this PR, both `Trait` and `Trait2` will see `struct S;`.
This is a [breaking-change], but I believe it is highly unlikely to cause breakage in practice.
r? @nrc
rustdoc: Show attributes on all item types
Currently attributes are only shown for structs, unions and enums but
they should be shown for all items. For example it is useful to know if a
function is `#[no_mangle]`.
improve error message when two-arg assert_eq! receives a trailing comma
Previously, `assert_eq!(left, right,)` (respectively, `assert_ne!(left,
right,)`; note the trailing comma) would result in a confusing "requires
at least a format string argument" error. In reality, a format string is
optional, but the trailing comma puts us into the "match a token tree of
zero or more tokens" branch of the macro (in order to support the
optional format string), and passing the empty token tree into
`format_args!` results in the confusing error. If instead we match a
token tree of one or more tokens, we get a much more sensible
"unexpected end of macro invocation" error.
While we're here, fix up a stray space before a comma in the match
guards.
Resolves#39369.
-----
**Before:**
```
$ rustc scratch.rs
error: requires at least a format string argument
--> scratch.rs:2:5
|
2 | assert_eq!(1, 2,);
| ^^^^^^^^^^^^^^^^^^
|
= note: this error originates in a macro outside of the current crate
error: aborting due to previous error
```
**After:**
```
$ ./build/x86_64-unknown-linux-gnu/stage1/bin/rustc scratch.rs
error: unexpected end of macro invocation
--> scratch.rs:2:20
|
2 | assert_eq!(1, 2,);
| ^
```
remove wrong packed struct test
This UB was found by running the test under [Miri](https://github.com/solson/miri) which rejects these unsafe unaligned loads. 😄
Fix unsafe unaligned loads in test.
r? @eddyb
cc @Aatch @nikomatsakis
The `#[derive(PartialEq, Debug)]` impls on a packed struct contain undefined behaviour. Both generated impls take references to unaligned fields, which will fail to compile once we correctly treat that as unsafe (see https://github.com/rust-lang/rust/issues/27060).
This UB was found by running the test under [Miri](https://github.com/solson/miri/) which rejects these unsafe unaligned loads. 😄
Here's a simpler example:
```rust
struct Packed {
a: u8,
b: u64,
}
```
It expands to:
```rust
fn fmt(&self, __arg_0: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
match *self {
Packed { a: ref __self_0_0, b: ref __self_0_1 } => { // BAD: these patterns are unsafe
let mut builder = __arg_0.debug_struct("Packed");
let _ = builder.field("a", &&(*__self_0_0));
let _ = builder.field("b", &&(*__self_0_1));
builder.finish()
}
}
}
```
and
```rust
fn eq(&self, __arg_0: &Packed) -> bool {
match *__arg_0 {
Packed { a: ref __self_1_0, b: ref __self_1_1 } => // BAD: these patterns are unsafe
match *self {
Packed { a: ref __self_0_0, b: ref __self_0_1 } => // BAD: these patterns are unsafe
true && (*__self_0_0) == (*__self_1_0) &&
(*__self_0_1) == (*__self_1_1),
},
}
}
```
Exclude top-level macro expansions from source location override.
It occurred to me that a simple heuristic can address the issue #36382: any macros that expand into items (including `include!()`) don't need to be stepped over because there's not code to step through above a function scope level.
r? @michaelwoerister
Emit DW_AT_main_subprogram
This changes rustc to emit DW_AT_main_subprogram on the "main" program.
This lets gdb suitably stop at the user's main in response to
"start" (rather than the library's main, which is what happens
currently).
Fixes#32620
r? michaelwoerister
Stabilize static lifetime in statics
Stabilize the "static_in_const" feature. Blockers before this PR can be merged:
* [x] The [FCP with inclination to stabilize](https://github.com/rust-lang/rust/issues/35897#issuecomment-270441437) needs to be over. FCP lasts roughly three weeks, so will be over at Jan 25, aka this thursday.
* [x] Documentation needs to be added (#37928)
Closes#35897.
emit "align 1" metadata on loads/stores of packed structs
According to the LLVM reference:
> A value of 0 or an omitted align argument means that the operation has
the ABI alignment for the target.
So loads/stores of fields of packed structs need to have their align set
to 1. Implement that by tracking the alignment of `LvalueRef`s.
Fixes#39376.
r? @eddyb
