Auto merge of #52109 - michaelwoerister:ir-objs, r=alexcrichton
When doing linker-plugin based LTO, write LLVM bitcode obj-files instead of embedding the bitcode into the regular object file.
This PR makes the compiler emit LLVM bitcode object files instead of regular object files with the IR embed when compiling for linker-plugin-based LTO. The reasoning for switching the strategy is this:
- Embedding bitcode in a section of the object file actually makes us save bitcode twice in rlibs and Rust dylibs, once for linker-based LTO and once for rustc-based LTO. That's a waste of space.
- When compiling for plugin-based LTO, one usually has no use for the machine code also present in the object file. Generating it is a waste of time.
- When compiling for plugin-based LTO, `rustc` will skip running ThinLTO because the linker will do that anyway. This has the side effect of then generating poorly optimized machine code, which makes it even less useful (and may lead to users not knowing why their code is slow instead of getting an error).
- Not having machine code available makes it impossible for the linker to silently fall back to not inlining stuff across language boundaries.
- This is what Clang does and according to [the documentation](https://llvm.org/docs/BitCodeFormat.html#native-object-file-wrapper-format) is the better supported option.
- The current behavior (minus the runtime performance problems) is still available via `-Z embed-bitcode` (we might want to do this for `libstd` at some point).
Mark Rousskov [Sat, 7 Jul 2018 03:29:20 +0000 (21:29 -0600)]
Rollup merge of #52120 - japaric:mclass, r=alexcrichton
ARM: expose the "mclass" target feature
This let us differentiate, in conditional compilation context, between ARM Cortex-M targets, like
the `thumbv*` targets, and other ARM targets, like the ARM Cortex-A Linux targets.
r? @alexcrichton
cc @gnzlbg
cc rust-lang-nursery/stdsimd#437
The implementation is incorrect in two cases:
- `$HOME` is set, but empty.
- An entry for the user exists in `/etc/passwd`, but it's `pw_dir` is empty.
In both cases Rust considers an empty string to be a valid home directory. This contradicts the documentation, and is wrong in general.
Auto merge of #52021 - nikomatsakis:nll-region-errors, r=estebank
refactor and cleanup region errors for NLL
This is a WIP commit. It simplifies some of the code from https://github.com/rust-lang/rust/pull/51536 and extends a few more steps towards the errors that @davidtwco and I were shooting for. These are intended as a replacement for the general "unable to infer lifetime" messages -- one that is actually actionable. We're certainly not there yet, but the overall shape hopefully gets a bit clearer.
I'm thinking about trying to open up an internals thread to sketch out the overall plan and perhaps discuss how to get the wording right, which special cases to handle, etc.
Auto merge of #51953 - japaric:atomic-load-store, r=alexcrichton
enable Atomic*.{load,store} for ARMv6-M / MSP430
closes #45085
as proposed in https://github.com/rust-lang/rust/issues/45085#issuecomment-384825434
this commit adds an `atomic_cas` target option and extends the `#[cfg(target_has_atomic)]`
attribute to enable a subset of the `Atomic*` API on architectures that don't support atomic CAS
natively, like MSP430 and ARMv6-M.
- #51619 (rust: add initial changes to support powerpc64le musl)
- #51793 (Fix variant background color on hover in search results)
- #52005 (Update LLVM to bring in a wasm codegen fix)
- #52016 (Deduplicate error reports for statics)
- #52019 ([cross-lang-lto] Allow the linker to choose the LTO-plugin (which is useful when using LLD))
- #52030 (Any docs preposition change)
- #52031 (Strenghten synchronization in `Arc::is_unique`)
- #52033 ([Gardening] Update outdated comments: ByVal -> Scalar)
- #52055 (Include VS 2017 in error message.)
- #52063 (Add a link to the rustc docs)
- #52073 (Add a punch card to weird expressions test)
- #52080 (Improve dependency deduplication diagnostics)
- #52093 (rustc: Update tracking issue for wasm_import_module)
- #52096 (Fix typo in cell.rs)
Rollup merge of #52030 - bowbahdoe:patch-1, r=alexcrichton
Any docs preposition change
This changes the docs referring to where a user should be wary of depending on "Any" trait impls from warning about relying on them "outside" of their code to warning about relying on them "inside" of their code.
Rollup merge of #52019 - michaelwoerister:cross-lto-auto-plugin, r=alexcrichton
[cross-lang-lto] Allow the linker to choose the LTO-plugin (which is useful when using LLD)
This PR allows for not specifying an LTO-linker plugin but still let `rustc` invoke the linker with the correct plugin arguments. This is useful when using LLD which does not need the `-plugin` argument. Since LLD is the best linker for this scenario anyway, this change should improve ergonomics quite a bit.
Auto merge of #51861 - GuillaumeGomez:prevent-some-markdown-short-doc, r=QuietMisdreavus
Prevent some markdown transformation on short docblocks
Before:
<img width="1440" alt="screen shot 2018-06-28 at 01 46 01" src="https://user-images.githubusercontent.com/3050060/42005762-7d533bbe-7a76-11e8-8361-027886803399.png">
After:
<img width="1440" alt="screen shot 2018-06-28 at 01 46 02" src="https://user-images.githubusercontent.com/3050060/42005768-81bd59a0-7a76-11e8-819b-9b4be72579d6.png">
This is only performed on short doc blocks, not on plain ones. Not all transformations are prevented (you still have a few like urls, code blocks, etc...).
Rollup merge of #51619 - mksully22:ppc64le_rust, r=alexcrichton
rust: add initial changes to support powerpc64le musl
Initial changes to support rustc building on ppc64le with musl. A PR was also submitted to libc component https://github.com/rust-lang/libc/pull/1023 to add changes to libc musl definitions.
A PR was submitted on Alpine https://github.com/alpinelinux/aports/pull/4549 with equivalent temporary patches for building on Alpine for now.
As a verification test a github project was put together to build ppc64le versions of rustc, rust-stdlib, and cargo on Alpine, https://github.com/mksully22/ppc64le_alpine_rust_1.26.2
Jorge Aparicio [Sat, 30 Jun 2018 19:56:08 +0000 (14:56 -0500)]
enable Atomic*.{load,store} for ARMv6-M / MSP430
closes #45085
this commit adds an `atomic_cas` target option and an unstable `#[cfg(target_has_atomic_cas)]`
attribute to enable a subset of the `Atomic*` API on architectures that don't support atomic CAS
natively, like MSP430 and ARMv6-M.
Auto merge of #51936 - japaric:rust-lld, r=alexcrichton
rename rustc's lld to rust-lld
to not shadow the system installed LLD when linking with LLD.
Before:
- `-C linker=lld -Z linker-flavor=ld.lld` uses rustc's LLD
- It's not possible to use a system installed LLD that's named `lld`
With this commit:
- `-C linker=rust-lld -Z linker-flavor=ld.lld` uses rustc's LLD
- `-C linker=lld -Z linker-flavor=ld.lld` uses the system installed LLD
we don't offer guarantees about the availability of LLD in the rustc sysroot so we can rename the tool as long as we don't break the wasm32-unknown-unknown target which depends on it.
Auto merge of #51938 - zackmdavis:and_the_case_of_the_leaking_desugar, r=estebank
in which we plug the crack where `?`-desugaring leaked into errors
Most of the time, it's not a problem that the types of the arm bodies in
a desugared-from-`?` match are different (that is, specifically: in `x?`
where x is a `Result<A, B>`, the `Ok` arm body is an `A`, whereas the
`Err` arm diverges to return a `Result<A, B>`), because they're being
assigned to different places. But in tail position, the types do need to
match, and our error message was explicitly referring to "match arms",
which is confusing when there's no `match` in the sweetly sugared
source.
It is not without some misgivings that we pollute the clarity-of-purpose
of `note_error_origin` with the suggestion to wrap with `Ok` (the other
branches are pointing out the odd-arm-out in the HIR that is the origin
of the error; the new branch that issues the `Ok` suggestion is serving
a different purpose), but it's the natural place to do it given that
we're already matching on `ObligationCauseCode::MatchExpressionArm {
arm_span, source }` there.
Auto merge of #51964 - matthewjasper:unused-mut-mir-generation, r=nikomatsakis
[NLL] Fix various unused mut errors
Closes #51801
Closes #50897
Closes #51830
Closes #51904
cc #51918 - keeping this one open in case there are any more issues
This PR contains multiple changes. List of changes with examples of what they fix:
* Change mir generation so that the parameter variable doesn't get a name when a `ref` pattern is used as an argument
```rust
fn f(ref y: i32) {} // doesn't trigger lint
```
* Change mir generation so that by-move closure captures don't get first moved into a temporary.
```rust
let mut x = 0; // doesn't trigger lint
move || {
x = 1;
};
```
* Treat generator upvars the same as closure upvars
```rust
let mut x = 0; // This mut is now necessary and is not linted against.
move || {
x = 1;
yield;
};
```
Auto merge of #51803 - lucasem:rustdoc-code-hash-escape, r=GuillaumeGomez
rustdoc codeblock hash escape
So that docstring text such as the following (in a code block) can be created ergonomically:
```rust
let s = "
foo
# bar
baz
";
```
Such code in a docstring hide the <code> # bar</code> line.
Previously, using two consecutive hashes <code> ## bar</code> would turn the line into _shown_ `# bar`, losing the leading whitespace. A line of code like <code> # bar</code> (such as in the example above) **could not be represented** in the docstring text.
This commit makes the two consecutive hashes not also trim the leading whitespace — the two hashes simply **escape** into a single hash and do not hide the line, leaving the rest of that line unaffected. The new docstring text to achieve the above code block is:
```rust
/// ```
/// let s = "
/// foo
/// ## bar
/// baz
/// ";
/// ```
```
The thrilling conclusion of the cross-crate macro saga in rustdoc! After https://github.com/rust-lang/rust/pull/51425 made sure we saw all the namespaces of an import (and prevented us from losing the `vec!` macro in std's documentation), here is the PR to handle cross-crate macro re-exports at the same time as everything else. This way, attributes like `#[doc(hidden)]` and `#[doc(no_inline)]` can be used to control how the documentation for these macros is seen, rather than rustdoc inlining every macro every time.