Auto merge of #74955 - P1n3appl3:rustdoc-formats, r=GuillaumeGomez
Add `--output-format json` for Rustdoc on nightly
This enables the previously deprecated `--output-format` flag so it can be used on nightly to host the experimental implementation of [rfc/2963](https://github.com/rust-lang/rfcs/pull/2963). The actual implementation will come in later PRs so for now there's just a stub that gives you an ICE.
I'm _pretty_ sure that the logic I added makes it inaccessible from stable, but someone should double check that. @tmandry @jyn514
Auto merge of #74682 - alexcrichton:backtrace-gimli-round-2, r=Mark-Simulacrum
std: Switch from libbacktrace to gimli (take 2)
This is the second attempt to land https://github.com/rust-lang/rust/pull/73441 after being reverted in https://github.com/rust-lang/rust/pull/74613. Will be gathering precise perf numbers here in this take.
Rollup merge of #74934 - nbdd0121:issue-73976, r=ecstatic-morse
Improve diagnostics when constant pattern is too generic
This PR is a follow-up to PR #74538 and issue #73976
When constants queries Layout, TypeId or type_name of a generic parameter, instead of emitting `could not evaluate constant pattern`, we will instead emit a more detailed message `constant pattern depends on a generic parameter`.
Rollup merge of #74915 - alexcrichton:allow-failing-canonicalize, r=Mark-Simulacrum
rustc: Ignore fs::canonicalize errors in metadata
This commit updates the metadata location logic to ignore errors when
calling `fs::canonicalize`. Canonicalization was added historically so
multiple `-L` paths to the same directory don't print errors about
multiple candidates (since rustc can deduplicate same-named paths), but
canonicalization doesn't work on all filesystems. Cargo, for example,
always uses this sort of fallback where it will opportunitistically try
to canonicalize but fall back to using the input path if it otherwise
doesn't work.
If rustc is run on a filesystem that doesn't support canonicalization
then the effect of this change will be that `-L` paths which logically
point to the same directory will cause errors, but that's a rare enough
occurrence it shouldn't cause much issue in practice. Otherwise rustc
doesn't work at all today on those sorts of filesystem where
canonicalization isn't supported!
Rollup merge of #74871 - etherealist:musl_doc, r=Mark-Simulacrum
Enable docs on dist-x86_64-musl
Add the `rust-docs` component to toolchain `x86_64-unknown-linux-musl`, which allows people using rustup on their musl-based linux distribution to download the rust-docs.
`--disable-docs` is based on the assumption that `x86_64-unknown-linux-musl` is only a cross-compile target.
I have tested that the docs are built. I assume the build-system will automatically detect the docs and create a `rust-docs` component. I will [monitor](https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-musl.html) the components and create a follow-up PR, if the docs aren't published.
See also #70619, where we enabled `rust-lld` to enable the wasm-workflow on musl-based linux distributions.
Alex Crichton [Wed, 29 Jul 2020 16:10:07 +0000 (09:10 -0700)]
rustc: Ignore fs::canonicalize errors in metadata
This commit updates the metadata location logic to ignore errors when
calling `fs::canonicalize`. Canonicalization was added historically so
multiple `-L` paths to the same directory don't print errors about
multiple candidates (since rustc can deduplicate same-named paths), but
canonicalization doesn't work on all filesystems. Cargo, for example,
always uses this sort of fallback where it will opportunitistically try
to canonicalize but fall back to using the input path if it otherwise
doesn't work.
If rustc is run on a filesystem that doesn't support canonicalization
then the effect of this change will be that `-L` paths which logically
point to the same directory will cause errors, but that's a rare enough
occurrence it shouldn't cause much issue in practice. Otherwise rustc
doesn't work at all today on those sorts of filesystem where
canonicalization isn't supported!
Fix clashing_extern_declarations warning for `#[repr(transparent)]` structs and safely-FFI-convertible enums, and not warning for clashes of struct members of different types, but the same size.
Auto merge of #74930 - ecstatic-morse:const-size-align-of-val, r=oli-obk
Make `mem::size_of_val` and `mem::align_of_val` unstably const
Implements #46571 but does not stabilize it. I wanted this while working on something today.
The only reason not to immediately stabilize are concerns around [custom DSTs](https://github.com/rust-lang/rust/issues/46571#issuecomment-387669352). That proposal has made zero progress in the last two years and const eval is rich enough to support pretty much any user-defined `len` function as long as nightly features are allowed (`raw_ptr_deref`).
Currently, this raises a `const_err` lint when passed an `extern type`.
- Make `is_repr_nullable_ptr` freestanding again to avoid usage of
ImproperCTypesVisitor in ClashingExternDeclarations (and don't
accidentally revert the ParamEnv::reveal_all() fix from a week earlier)
- Revise match condition for 1 Adt, 1 primitive
- Generalise check for non-null type so that it would also work for
ranges which exclude any single value (all bits set, for example)
- Make is_repr_nullable_ptr return the representable type instead of
just a boolean, to avoid adding an additional, independent "source of
truth" about the FFI-compatibility of Option-like enums. Also, rename to
`repr_nullable_ptr`.
An example of an FFI-safe enum conversion is when converting
Option<NonZeroUsize> to usize. Because the Some value must be non-zero,
rustc can use 0 to represent the None variant, making this conversion is
safe. Furthermore, it can be relied on (and removing this optimisation
already would be a breaking change).
Auto merge of #74105 - npmccallum:naked, r=matthewjasper
Suppress debuginfo on naked function arguments
A function that has no prologue cannot be reasonably expected to support
debuginfo. In fact, the existing code (before this patch) would generate
invalid instructions that caused crashes. We can solve this easily by
just not emitting the debuginfo in this case.
Fixes https://github.com/rust-lang/rust/issues/42779
cc https://github.com/rust-lang/rust/issues/32408
Auto merge of #74876 - oli-obk:lumberjack_disable, r=RalfJung
Replace all uses of `log::log_enabled` with `Debug` printers
cc @RalfJung this touches a bunch of logging in the miri engine. There are some visual changes, mainly that in several cases we stop prepending lines with the module path and just have a newline.
Auto merge of #74923 - ehuss:update-cargo, r=Mark-Simulacrum
Update cargo
14 commits in aa6872140ab0fa10f641ab0b981d5330d419e927..974eb438da8ced6e3becda2bbf63d9b643eacdeb
2020-07-23 13:46:27 +0000 to 2020-07-29 16:15:05 +0000
- Fix O0 build scripts by default without `[profile.release]` (rust-lang/cargo#8560)
- Emphasize git dependency version locking behavior. (rust-lang/cargo#8561)
- Update lock file encodings on changes (rust-lang/cargo#8554)
- Fix sporadic lto test failures. (rust-lang/cargo#8559)
- build-std: Fix libraries paths following upstream (rust-lang/cargo#8558)
- Flag git http errors as maybe spurious (rust-lang/cargo#8553)
- Display builtin aliases with `cargo --list` (rust-lang/cargo#8542)
- Check manifest for requiring nonexistent features (rust-lang/cargo#7950)
- Clarify test name filter usage (rust-lang/cargo#8552)
- Revert Cargo Book changes for default edition (rust-lang/cargo#8551)
- Prepare for not defaulting to master branch for git deps (rust-lang/cargo#8522)
- Include `+` for crates.io feature requirements in the Cargo Book section on features (rust-lang/cargo#8547)
- Update termcolor and fwdansi versions (rust-lang/cargo#8540)
- Cargo book nitpick in Manifest section (rust-lang/cargo#8543)
Auto merge of #74929 - Manishearth:rollup-z2vflrp, r=Manishearth
Rollup of 10 pull requests
Successful merges:
- #74742 (Remove links to rejected errata 4406 for RFC 4291)
- #74819 (Point towards `format_spec`; it is in other direction)
- #74852 (Explain why inlining default ToString impl)
- #74869 (Make closures and generators a must use types)
- #74873 (symbol mangling: use ty::print::Print for consts)
- #74902 (Remove deprecated unstable `{Box,Rc,Arc}::into_raw_non_null` functions)
- #74904 (Fix some typos in src/librustdoc/clean/auto_trait.rs)
- #74910 (fence docs: fix example Mutex)
- #74912 (Fix broken link in unstable book `plugin`)
- #74927 (Change the target data layout to specify more values)
Rollup merge of #74927 - Lokathor:Lokathor-patch-1, r=jonas-schievink
Change the target data layout to specify more values
This does not actually alter the previously specified important parts, but apparently `rustc` cares about more layout components than `cargo-xbuild` ever did. This extends the data layout to be a fully specified layout, as given in the error from issue #74767
Rollup merge of #74869 - tmiasko:must-use-closures, r=ecstatic-morse
Make closures and generators a must use types
Warn about unused expressions with closure or generator type. This follows
existing precedence of must use annotations present on `FnOnce`, `FnMut`, `Fn`
traits, which already indirectly apply to closures in some cases, e.g.,:
```rust
fn f() -> impl FnOnce() {
|| {}
}
fn main() {
// an existing warning: unused implementer of `std::ops::FnOnce` that must be used:
f();
// a new warning: unused closure that must be used:
|| {};
}
```
Rollup merge of #74852 - lzutao:inline-rm-tostring, r=nnethercote
Explain why inlining default ToString impl
Trying to remove inline attribute from default ToString impl causes regression.
Perf result at <https://github.com/rust-lang/rust/pull/74852#issuecomment-664812994>.
Rollup merge of #74742 - poliorcetics:ip-addr-remove-rejected-errata, r=nikomatsakis
Remove links to rejected errata 4406 for RFC 4291
Fixes #74198.
For now I simply removed the links, the docs seems clear enough to me but I'm no expert in the domain so don't hesitate to correct me if more is needed.
Change the target data layout to specify more values
This does not actually alter the previously specified important parts, but apparently `rustc` cares about more layout components than `cargo-xbuild` ever did. This extends the data layout to be fully specified layout, as given in the error from issue #74767
Auto merge of #73767 - P1n3appl3:rustdoc-formats, r=tmandry
Refactor librustdoc html backend
This PR moves several types out of the librustdoc::html module so that they can be used by a future json backend. These changes are a re-implementation of [some work done 6 months ago](https://github.com/rust-lang/rust/compare/master...GuillaumeGomez:multiple-output-formats) by @GuillaumeGomez. I'm currently working on said json backend and will put up an RFC soon with the proposed implementation.
There are a couple of changes that are more substantial than relocating structs to a different module:
1. The `Cache` is no longer part of the `html::render::Context` type and therefor it needs to be explicitly passed to any functions that access it.
2. The driving function `html::render::run` has been rewritten to use the `FormatRenderer` trait which should allow different backends to re-use the driving code.
Auto merge of #74733 - richkadel:llvm-coverage-map-gen-5, r=tmandry
Fixed coverage map issues; better aligned with LLVM APIs
Found some problems with the coverage map encoding when testing with more than one counter per function.
While debugging, I realized some better ways to structure the Rust implementation of the coverage mapping generator. I refactored somewhat, resulting in less code overall, expanded coverage of LLVM Coverage Map capabilities, and much closer alignment with LLVM data structures, APIs, and naming.
This should be easier to follow and easier to maintain.
r? @tmandry
Rust compiler MCP rust-lang/compiler-team#278
Relevant issue: #34701 - Implement support for LLVMs code coverage instrumentation
Auto merge of #74837 - xldenis:mir-dump-crate-file, r=oli-obk
Fix #70767
This PR changes the format of MIR dump filenames to include the crate name rather than `rustc` at the start.
As a result, we can now place mir-opt tests in the same directory as the source files, like with UI tests. I had to make sure that `compiletest` added a bit_width suffix to the expected files when appropriate but otherwise the change is only moving the files to the correct location and ensuring that the `EMIT_MIR` lines are correct.
Auto merge of #72488 - KodrAus:stabilize/const_type_id, r=nikomatsakis
Stabilize const_type_id feature
The tracking issue for `const_type_id` points to the ill-fated #41875. So I'm re-energizing `TypeId` shenanigans by opening this one up to see if there's anything blocking us from stabilizing the constification of type ids.
Will wait for CI before pinging teams/groups.
-----
This PR stabilizes the `const_type_id` feature, which allows `TypeId::of` (and the underlying unstable intrinsic) to be called in constant contexts.
There are some [sanity tests](https://github.com/rust-lang/rust/blob/master/src/test/ui/consts/const-typeid-of-rpass.rs) that demonstrate its usage, but I’ve included some more below.
As a simple example, you could create a constant item that contains some type ids:
`TypeId::of` is generic, which we saw above in the way the generic `Self` argument was used. This has some implications for const evaluation. It means we can make trait impls evaluate differently depending on information that wasn't directly passed through the trait system. This violates the _parametricity_ property, which requires all instances of a generic function to behave the same way with respect to its generic parameters. That's not unique to `TypeId::of`, other generic const functions based on compiler intrinsics like `mem::align_of` can also violate parametricity. In practice Rust doesn't really have type parametricity anyway since it monomorphizes generics into concrete functions, so violating it using type ids isn’t new.
As an example of how impls can behave differently, you could combine constant type ids with the `const_if_match` feature to dispatch calls based on the type id of the generic `Self`, rather than based on information about `Self` that was threaded through trait bounds. It's like a rough-and-ready form of specialization:
```rust
#![feature(const_if_match)]
trait Specialized where Self: 'static {
// An associated constant that determines the function to call
// at compile-time based on `TypeId::of::<Self>`.
const CALL: fn(&Self) = {
const USIZE: TypeId = TypeId::of::<usize>();
match TypeId::of::<Self>() {
// Use a closure for `usize` that transmutes the generic `Self` to
// a concrete `usize` and dispatches to `Self::usize`.
USIZE => |x| Self::usize(unsafe { &*(x as *const Self as *const usize) }),
// For other types, dispatch to the generic `Self::default`.
_ => Self::default,
}
};
fn call(&self) {
// Call the function we determined at compile-time
(Self::CALL)(self)
}
fn default(x: &Self);
fn usize(x: &usize);
}
// Implement our `Specialized` trait for any `Debug` type.
impl<T: fmt::Debug + 'static> Specialized for T {
fn default(x: &Self) {
println!("default: {:?}", x);
}
// Will print "usize: 42"
Specialized::call(&42usize);
// Will print "default: ()"
Specialized::call(&());
```
Type ids have some edges that this stabilization exposes to more contexts. It's possible for type ids to collide (but this is a bug). Since they can change between compiler versions, it's never valid to cast a type id to its underlying value.
Auto merge of #72049 - mati865:mingw-lld, r=petrochenkov
MinGW: enable dllexport/dllimport
Fixes (only when using LLD) https://github.com/rust-lang/rust/issues/50176
Fixes https://github.com/rust-lang/rust/issues/72319
This makes `windows-gnu` on pair with `windows-msvc` when it comes to symbol exporting.
For MinGW it means both good things like correctly working dllimport/dllexport, ability to link with LLD and bad things like https://github.com/rust-lang/rust/issues/27438.
Not sure but maybe this should land behind unstable compiler option (`-Z`) or environment variable?
Mateusz Mikuła [Thu, 7 May 2020 09:52:21 +0000 (11:52 +0200)]
MinGW: emit dllexport/dllimport by rustc
This fixes various cases where LD could not guess dllexport correctly and greatly improves compatibility with LLD which is not going to support linker scripts anytime soon
Auto merge of #74900 - tmiasko:doc-open, r=Mark-Simulacrum
Fix opening docs for std crates with ./x.py doc --open library/*
The directories for core, alloc, std, proc_macro, and test crates now
correspond directly to the crate name, and stripping the "lib" prefix is
no longer necessary.
Tomasz Miąsko [Wed, 29 Jul 2020 00:00:00 +0000 (00:00 +0000)]
Fix opening docs for std crates with ./x.py doc --open library/*
The directories for core, alloc, std, proc_macro, and test crates now
correspond directly to the crate name and stripping the "lib" prefix is
no longer necessary.
Auto merge of #74887 - Mark-Simulacrum:cache-non-exhaustive, r=petrochenkov
Cache non-exhaustive separately from attributes
This prevents cross-crate attribute loading from metadata just for non_exhaustive checking; cross-crate attribute loading implies disk reading and is relatively slow.
Rollup merge of #74872 - JohnTitor:ping-risc-v, r=Mark-Simulacrum
Enable to ping RISC-V group via triagebot
We have the RISC-V group (https://github.com/rust-lang/team/blob/master/teams/risc-v.toml) but don't enable to ping on this repository (https://github.com/rust-lang/rust/pull/74813#issuecomment-664841177).
We don't have the instructions on the rustc-dev-guide yet but I'll create it soonish.
Auto merge of #74791 - tmiasko:raw-waker-inline, r=LukasKalbertodt
Add #[inline] to RawWaker::new
`RawWaker::new` is used when creating a new waker or cloning an existing one,
for example as in code below. The `RawWakerVTable::new` can be const evaluated,
but `RawWaker::new` itself cannot since waker pointer is not known at compile
time. Add `#[inline]` to avoid overhead of a function call.
Alex Crichton [Wed, 13 May 2020 21:22:37 +0000 (14:22 -0700)]
std: Switch from libbacktrace to gimli
This commit is a proof-of-concept for switching the standard library's
backtrace symbolication mechanism on most platforms from libbacktrace to
gimli. The standard library's support for `RUST_BACKTRACE=1` requires
in-process parsing of object files and DWARF debug information to
interpret it and print the filename/line number of stack frames as part
of a backtrace.
Historically this support in the standard library has come from a
library called "libbacktrace". The libbacktrace library seems to have
been extracted from gcc at some point and is written in C. We've had a
lot of issues with libbacktrace over time, unfortunately, though. The
library does not appear to be actively maintained since we've had
patches sit for months-to-years without comments. We have discovered a
good number of soundness issues with the library itself, both when
parsing valid DWARF as well as invalid DWARF. This is enough of an issue
that the libs team has previously decided that we cannot feed untrusted
inputs to libbacktrace. This also doesn't take into account the
portability of libbacktrace which has been difficult to manage and
maintain over time. While possible there are lots of exceptions and it's
the main C dependency of the standard library right now.
For years it's been the desire to switch over to a Rust-based solution
for symbolicating backtraces. It's been assumed that we'll be using the
Gimli family of crates for this purpose, which are targeted at safely
and efficiently parsing DWARF debug information. I've been working
recently to shore up the Gimli support in the `backtrace` crate. As of a
few weeks ago the `backtrace` crate, by default, uses Gimli when loaded
from crates.io. This transition has gone well enough that I figured it
was time to start talking seriously about this change to the standard
library.
This commit is a preview of what's probably the best way to integrate
the `backtrace` crate into the standard library with the Gimli feature
turned on. While today it's used as a crates.io dependency, this commit
switches the `backtrace` crate to a submodule of this repository which
will need to be updated manually. This is not done lightly, but is
thought to be the best solution. The primary reason for this is that the
`backtrace` crate needs to do some pretty nontrivial filesystem
interactions to locate debug information. Working without `std::fs` is
not an option, and while it might be possible to do some sort of
trait-based solution when prototyped it was found to be too unergonomic.
Using a submodule allows the `backtrace` crate to build as a submodule
of the `std` crate itself, enabling it to use `std::fs` and such.
Otherwise this adds new dependencies to the standard library. This step
requires extra attention because this means that these crates are now
going to be included with all Rust programs by default. It's important
to note, however, that we're already shipping libbacktrace with all Rust
programs by default and it has a bunch of C code implementing all of
this internally anyway, so we're basically already switching
already-shipping functionality to Rust from C.
* `object` - this crate is used to parse object file headers and
contents. Very low-level support is used from this crate and almost
all of it is disabled. Largely we're just using struct definitions as
well as convenience methods internally to read bytes and such.
* `addr2line` - this is the main meat of the implementation for
symbolication. This crate depends on `gimli` for DWARF parsing and
then provides interfaces needed by the `backtrace` crate to turn an
address into a filename / line number. This crate is actually pretty
small (fits in a single file almost!) and mirrors most of what
`dwarf.c` does for libbacktrace.
* `miniz_oxide` - the libbacktrace crate transparently handles
compressed debug information which is compressed with zlib. This crate
is used to decompress compressed debug sections.
* `gimli` - not actually used directly, but a dependency of `addr2line`.
* `adler32`- not used directly either, but a dependency of
`miniz_oxide`.
The goal of this change is to improve the safety of backtrace
symbolication in the standard library, especially in the face of
possibly malformed DWARF debug information. Even to this day we're still
seeing segfaults in libbacktrace which could possibly become security
vulnerabilities. This change should almost entirely eliminate this
possibility whilc also paving the way forward to adding more features
like split debug information.
Some references for those interested are:
* Original addition of libbacktrace - #12602
* OOM with libbacktrace - #24231
* Backtrace failure due to use of uninitialized value - #28447
* Possibility to feed untrusted data to libbacktrace - #21889
* Soundness fix for libbacktrace - #33729
* Crash in libbacktrace - #39468
* Support for macOS, never merged - ianlancetaylor/libbacktrace#2
* Performance issues with libbacktrace - #29293, #37477
* Update procedure is quite complicated due to how many patches we
need to carry - #50955
* Libbacktrace doesn't work on MinGW with dynamic libs - #71060
* Segfault in libbacktrace on macOS - #71397
Switching to Rust will not make us immune to all of these issues. The
crashes are expected to go away, but correctness and performance may
still have bugs arise. The gimli and `backtrace` crates, however, are
actively maintained unlike libbacktrace, so this should enable us to at
least efficiently apply fixes as situations come up.