This attempts to keep the logic as close to the original python as possible.
`probably_large` has been removed, since it was always `True`, and UTF-8 paths are no longer supported when patching files for NixOS.
I can readd UTF-8 support if desired.
Note that this required making `llvm_link_shared` computed on-demand,
since we don't know whether it will be static or dynamic until we download LLVM from CI.
Update cargo
7 commits in dba5baf4345858c591517b24801902a062c399f8..edffc4ada3d77799e5a04eeafd9b2f843d29fc23
2022-04-13 21:58:27 +0000 to 2022-04-19 17:38:29 +0000
- Document cargo-add (rust-lang/cargo#10578)
- feat: Support '-F' as an alias for '--features' (rust-lang/cargo#10576)
- Completion support for `cargo-add` (rust-lang/cargo#10577)
- Add a link to the document in the timings report (rust-lang/cargo#10492)
- feat: Import cargo-add into cargo (rust-lang/cargo#10472)
- Part 8 of RFC2906 - Keep `InheritableFields` in a `LazyCell` inside `… (rust-lang/cargo#10568)
- Part 7 of RFC2906 - Add support for inheriting `exclude` and `include` (rust-lang/cargo#10565)
Remove `--extern-location` and all associated code
`--extern-location` was an experiment to investigate the best way to
generate useful diagnostics for unused dependency warnings by enabling a
build system to identify the corresponding build config.
While I did successfully use this, I've since been convinced the
alternative `--json unused-externs` mechanism is the way to go, and
there's no point in having two mechanisms with basically the same
functionality.
This effectively reverts https://github.com/rust-lang/rust/pull/72603
Add support for LibreSSL 3.4.x
This updates the `openssl` and `openssl-sys` crates to support building
the toolchain with system libraries up to LibreSSL 3.4.x.
LibreSSL 3.4.0 has been supported since `openssl-sys` version 0.9.67,
LibreSSL 3.4.x since `openssl-sys` 0.9.72.
This updates the `openssl` and `openssl-sys` crates to support building
the toolchain with system libraries up to LibreSSL 3.4.x.
LibreSSL 3.4.0 has been supported since `openssl-sys` version 0.9.67,
LibreSSL 3.4.x since `openssl-sys` 0.9.72.
`--extern-location` was an experiment to investigate the best way to
generate useful diagnostics for unused dependency warnings by enabling a
build system to identify the corresponding build config.
While I did successfully use this, I've since been convinced the
alternative `--json unused-externs` mechanism is the way to go, and
there's no point in having two mechanisms with basically the same
functionality.
This effectively reverts https://github.com/rust-lang/rust/pull/72603
With the updated libc, UNIX stack overflow handling in libstd can now
use the common `si_addr` accessor function, rather than attempting to
use a field from that name in `siginfo_t`. This simplifies the
collection of the fault address, particularly on platforms where that
data resides within a union in `siginfo_t`.
Conditional on the parallel compiler being enabled, use a different
`IntlLangMemoizer` which supports being sent between threads in
`FluentBundle`.
Signed-off-by: David Wood <david.wood@huawei.com>
Extend loading of Fluent bundles so that bundles can be loaded from the
sysroot based on the language requested by the user, or using a nightly
flag.
Sysroot bundles are loaded from `$sysroot/share/locale/$locale/*.ftl`.
Signed-off-by: David Wood <david.wood@huawei.com>
This commit updates the signatures of all diagnostic functions to accept
types that can be converted into a `DiagnosticMessage`. This enables
existing diagnostic calls to continue to work as before and Fluent
identifiers to be provided. The `SessionDiagnostic` derive just
generates normal diagnostic calls, so these APIs had to be modified to
accept Fluent identifiers.
In addition, loading of the "fallback" Fluent bundle, which contains the
built-in English messages, has been implemented.
Each diagnostic now has "arguments" which correspond to variables in the
Fluent messages (necessary to render a Fluent message) but no API for
adding arguments has been added yet. Therefore, diagnostics (that do not
require interpolation) can be converted to use Fluent identifiers and
will be output as before.
`MultiSpan` contains labels, which are more complicated with the
introduction of diagnostic translation and will use types from
`rustc_errors` - however, `rustc_errors` depends on `rustc_span` so
`rustc_span` cannot use types like `DiagnosticMessage` without
dependency cycles. Introduce a new `rustc_error_messages` crate that can
contain `DiagnosticMessage` and `MultiSpan`.
Signed-off-by: David Wood <david.wood@huawei.com>
The majority of the code is only used by either rustbuild or
rustc_llvm's build script. Rust_build is compiled once for rustbuild and
once for every stage. This means that the majority of the code in this
crate is needlessly compiled multiple times. By moving only the code
actually used by the respective crates to rustbuild and rustc_llvm's
build script, this needless duplicate compilation is avoided.
Bump autocfg to 1.1.0
autocfg 1.1.0 makes it so that rustflags from the build are correctly
passed to the compiler probes, which in turn means those probes more
accurately reflect the outer build conditions. This is particularly
important if rustflags includes _required_ `-Clink-arg=` flags without
which builds will fail, as older versions of `autocfg` will then fail
the probe and erroneously report the probed feature as unavailable.
See also
https://github.com/rust-lang/rust/issues/94007#issuecomment-1040668261
Remove num_cpus dependency from bootstrap, build-manifest and rustc_s…
…ession
`std::threads::available_parallelism` was stabilized in rust 1.59.
r? ```````````````````````````@Mark-Simulacrum```````````````````````````
autocfg 1.1.0 makes it so that rustflags from the build are correctly
passed to the compiler probes, which in turn means those probes more
accurately reflect the outer build conditions. This is particularly
important if rustflags includes _required_ `-Clink-arg=` flags without
which builds will fail, as older versions of `autocfg` will then fail
the probe and erroneously report the probed feature as unavailable.
See also
https://github.com/rust-lang/rust/issues/94007#issuecomment-1040668261
debuginfo: Simplify TypeMap used during LLVM debuginfo generation.
This PR simplifies the TypeMap that is used in `rustc_codegen_llvm::debuginfo::metadata`. It was unnecessarily complicated because it was originally implemented when types were not yet normalized before codegen. So it did it's own normalization and kept track of multiple unnormalized types being mapped to a single unique id.
This PR is based on https://github.com/rust-lang/rust/pull/93503, which is not merged yet.
The PR also removes the arena used for allocating string ids and instead uses `InlinableString` from the [inlinable_string](https://crates.io/crates/inlinable_string) crate. That might not be the best choice, since that crate does not seem to be very actively maintained. The [flexible-string](https://crates.io/crates/flexible-string) crate would be an alternative.
r? `@ghost`
The previous implementation was written before types were properly
normalized for code generation and had to assume a more complicated
relationship between types and their debuginfo -- generating separate
identifiers for debuginfo nodes that were based on normalized types.
Since types are now already normalized, we can use them as identifiers
for debuginfo nodes.
removing architecture requirements for RustyHermit
RustHermit and HermitCore is able to run on aarch64 and x86_64. In the future these operating systems will also support RISC-V. Consequently, the dependency to a specific target should be removed.
The build process of `hermit-abi` fails if the architecture isn't supported.
RustHermit and HermitCore is able to run on aarch64 and x86_64.
In the future these operating systems will also support RISC-V.
Consequently, the dependency to a specific target should be removed.
Building hermit-abi fails if the architecture isn't supported.
Drop time dependency from bootstrap
This was only used for the inclusion of 'current' dates into our manpages, but
it is not clear that this is practically necessary. The manpage is essentially
never updated, and so we can likely afford to keep a manual date in these files.
It also seems possible to just omit it, but that may cause other tools trouble,
so avoid doing that for now.
This is largely done to reduce bootstrap complexity; the time crate is not particularly
small and in #92480 would have started pulling in num-threads, which does runtime
thread count detection. I would prefer to avoid that, so filing this to just drop the nearly
unused dependency entirely.
r? `@pietroalbini`
This was only used for the inclusion of 'current' dates into our manpages, but
it is not clear that this is practically necessary. The manpage is essentially
never updated, and so we can likely afford to keep a manual date in these files.
It also seems possible to just omit it, but that may cause other tools trouble,
so avoid doing that for now.
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
Bump libc and fix remove_dir_all on Fuchsia after CVE fix
With the previous `is_dir` impl, we would attempt to unlink
a directory in the None branch, but Fuchsia supports returning
ENOTEMPTY from unlinkat() without the AT_REMOVEDIR flag because
we don't currently differentiate unlinking files and directories
by default.
On the Fuchsia side I've opened https://fxbug.dev/92273 to discuss
whether this is the correct behavior, but it doesn't seem like
addressing the error code is necessary to make our tests happy.
Depends on https://github.com/rust-lang/libc/pull/2654 since we
apparently haven't needed to reference DT_UNKNOWN before this.
With the previous `is_dir` impl, we would attempt to unlink
a directory in the None branch, but Fuchsia supports returning
ENOTEMPTY from unlinkat() without the AT_REMOVEDIR flag because
we don't currently differentiate unlinking files and directories
by default.
On the Fuchsia side I've opened https://fxbug.dev/92273 to discuss
whether this is the correct behavior, but it doesn't seem like
addressing the error code is necessary to make our tests happy.
Updates std's libc crate to include DT_UNKNOWN for Fuchsia.
Update some rustc dependencies to deduplicate them
This PR updates `rand` and `itertools` in rustc (not the whole workspace) in order to deduplicate them (and hopefully slightly improve compile times).
~~Currently, `object` is still duplicated, but https://github.com/rust-lang/thorin/pull/15 and updating `thorin` in the future will remove the use of version 0.27.~~ Update: Thorin 0.2 has now been released, and this PR updates `rustc_codegen_ssa` to use it and deduplicate the `object` crate.
There's a final tiny rustc dependency, `cfg-if`, which will be left: as both versions 0.1.x and 1.0 looked to be heavily depended on, they will require a few cascading updates to be removed.
Introduce drop range tracking to generator interior analysis
This PR addresses cases such as this one from #57478:
```rust
struct Foo;
impl !Send for Foo {}
let _: impl Send = || {
let guard = Foo;
drop(guard);
yield;
};
```
Previously, the `generator_interior` pass would unnecessarily include the type `Foo` in the generator because it was not aware of the behavior of `drop`. We fix this issue by introducing a drop range analysis that finds portions of the code where a value is guaranteed to be dropped. If a value is dropped at all suspend points, then it is no longer included in the generator type. Note that we are using "dropped" in a generic sense to include any case in which a value has been moved. That is, we do not only look at calls to the `drop` function.
There are several phases to the drop tracking algorithm, and we'll go into more detail below.
1. Use `ExprUseVisitor` to find values that are consumed and borrowed.
2. `DropRangeVisitor` uses consume and borrow information to gather drop and reinitialization events, as well as build a control flow graph.
3. We then propagate drop and reinitialization information through the CFG until we reach a fix point (see `DropRanges::propagate_to_fixpoint`).
4. When recording a type (see `InteriorVisitor::record`), we check the computed drop ranges to see if that value is definitely dropped at the suspend point. If so, we skip including it in the type.
## 1. Use `ExprUseVisitor` to find values that are consumed and borrowed.
We use `ExprUseVisitor` to identify the places where values are consumed. We track both the `hir_id` of the value, and the `hir_id` of the expression that consumes it. For example, in the expression `[Foo]`, the `Foo` is consumed by the array expression, so after the array expression we can consider the `Foo` temporary to be dropped.
In this process, we also collect values that are borrowed. The reason is that the MIR transform for generators conservatively assumes anything borrowed is live across a suspend point (see `rustc_mir_transform::generator::locals_live_across_suspend_points`). We match this behavior here as well.
## 2. Gather drop events, reinitialization events, and control flow graph
After finding the values of interest, we perform a post-order traversal over the HIR tree to find the points where these values are dropped or reinitialized. We use the post-order index of each event because this is how the existing generator interior analysis refers to the position of suspend points and the scopes of variables.
During this traversal, we also record branching and merging information to handle control flow constructs such as `if`, `match`, and `loop`. This is necessary because values may be dropped along some control flow paths but not others.
## 3. Iterate to fixed point
The previous pass found the interesting events and locations, but now we need to find the actual ranges where things are dropped. Upon entry, we have a list of nodes ordered by their position in the post-order traversal. Each node has a set of successors. For each node we additionally keep a bitfield with one bit per potentially consumed value. The bit is set if we the value is dropped along all paths entering this node.
To compute the drop information, we first reverse the successor edges to find each node's predecessors. Then we iterate through each node, and for each node we set its dropped value bitfield to the intersection of all incoming dropped value bitfields.
If any bitfield for any node changes, we re-run the propagation loop again.
## 4. Ignore dropped values across suspend points
At this point we have a data structure where we can ask whether a value is guaranteed to be dropped at any post order index for the HIR tree. We use this information in `InteriorVisitor` to check whether a value in question is dropped at a particular suspend point. If it is, we do not include that value's type in the generator type.
Note that we had to augment the region scope tree to include all yields in scope, rather than just the last one as we did before.
r? `@nikomatsakis`
All tests pass now! The issue was that we weren't handling all edges
correctly, but now they are handled consistently.
This includes code to dump a graphviz file for the CFG we built for drop
tracking.
Also removes old DropRanges tests.
This adds support for branching and merging control flow and uses this
to correctly handle the case where a value is dropped in one branch of
an if expression but not another.
There are other cases we need to handle, which will come in follow up
patches.
Issue #57478
ProjectionPredicate should be able to handle both associated types and consts so this adds the
first step of that. It mainly just pipes types all the way down, not entirely sure how to handle
consts, but hopefully that'll come with time.
rustdoc: remove hand-rolled isatty
This PR replaces bindings to the platform-specific isatty APIs with the `isatty` crate, as done elsewhere in the repository.
Update rayon and rustc-rayon
This updates rayon for various tools and rustc-rayon for the compiler's parallel mode.
- rayon v1.3.1 -> v1.5.1
- rayon-core v1.7.1 -> v1.9.1
- rustc-rayon v0.3.1 -> v0.3.2
- rustc-rayon-core v0.3.1 -> v0.3.2
... and indirectly, this updates all of crossbeam-* to their latest versions.
Fixes#92677 by removing crossbeam-queue, but there's still a lingering question about how tidy discovers "runtime" dependencies. None of this is truly in the standard library's dependency tree at all.
Update cargo
6 commits in 358e79fe56fe374649275ca7aebaafd57ade0e8d..06b9d31743210b788b130c8a484c2838afa6fc27
2022-01-04 18:39:45 +0000 to 2022-01-11 23:47:29 +0000
- Port cargo to clap3 (rust-lang/cargo#10265)
- feat: support rustflags per profile (rust-lang/cargo#10217)
- Make bors ignore the PR template so it doesn't end up in merge messages (rust-lang/cargo#10267)
- Be resilient to most IO error and filesystem loop while walking dirs (rust-lang/cargo#10214)
- Remove the option to disable pipelining (rust-lang/cargo#10258)
- Always ask rustc for messages about artifacts, and always process them (rust-lang/cargo#10255)
Make rlib metadata strip works with MIPSr6 architecture
Because MIPSr6 has many differences with previous MIPSr2 arch, the previous rlib metadata stripping code in `rustc_codegen_ssa` is only for MIPSr2/r3/r5 (which share the same elf e_flags).
This commit fixed this problem. It makes `rustc_codegen_ssa` happy when compiling rustc for MIPSr6 target or hosts.
e_flags REF: e356027016/llvm/include/llvm/BinaryFormat/ELF.h (L562)
`thorin` is a Rust implementation of a DWARF packaging utility that
supports reading DWARF objects from archive files (i.e. rlibs) and
therefore is better suited for integration into rustc.
Signed-off-by: David Wood <david.wood@huawei.com>
Extract init_env_logger to crate
I've been doing some work on rustc_ast_pretty using an out-of-tree main.rs and Cargo.toml with the following:
```toml
[dependencies]
rustc_ast = { path = "../rust/compiler/rustc_ast" }
rustc_ast_pretty = { path = "../rust/compiler/rustc_ast_pretty" }
rustc_span = { path = "../rust/compiler/rustc_span" }
```
Rustc_ast_pretty helpfully uses `tracing::debug!` but I found that in order to enable the debug output, my test crate must depend on rustc_driver which is an enormously bigger dependency than what I have been using so far, and slows down iteration time because an enormous dependency tree between rustc_ast and rustc_driver must now be rebuilt after every ast change.
I pulled out the tracing initialization to a new minimal rustc_log crate so that projects depending on the other rustc crates, like rustc_ast_pretty, can access the `debug!` messages in them without building all the rest of rustc.
The task of the macro is simple enough that a decl macro is almost ten
times shorter than the original proc macro. The proc macro is 159 lines
while the decl macro is just 18 lines.
This reduces the amount of dependencies of rustbuild from 45 to 37. It
also slight reduces compilation time from 47s to 44s for debug builds.
Store liveness in interval sets for region inference
On the 100,000 line test case from https://github.com/rust-lang/rust/issues/90445, this reduces memory usage from 35 GB to 444 MB at peak (based on DHAT results, though with regular malloc), and yields a 9.4x speedup, with wall time going from 14.5 seconds to 1.5s. Performance results show that for the majority of real-world code this has little to no impact, but it's expected to generally scale better for auto-generated functions and other cases which stress this area of the compiler, as results on #90445 illustrate.
There may also be further room for improvement in future PRs making use of this data structures benefits over raw bitsets (which, at some level, are a less perfect fit for representing liveness, which is almost always composed of contiguous ranges, not point locations).
Fixes#90445.
This is a compact, fast storage for variable-sized sets, typically consisting of
larger ranges. It is less efficient than a bitset if ranges are both small and
the domain size is small, but will still perform acceptably. With enormous
domain sizes and large ranges, the interval set performs much better, as it can
be much more densely packed in memory than the uncompressed bit set alternative.
Update chalk to 0.75.0
- Compute flags in `intern_ty`
- Remove `tracing-serde` from `PERMITTED_DEPENDENCIES`
- Bump `tracing-tree` to 0.2.0
- Bump `tracing-subscriber` to 0.3.3
Stabilize asm! and global_asm!
Tracking issue: #72016
It's been almost 2 years since the original [RFC](https://github.com/rust-lang/rfcs/pull/2850) was posted and we're finally ready to stabilize this feature!
The main changes in this PR are:
- Removing `asm!` and `global_asm!` from the prelude as per the decision in #87228.
- Stabilizing the `asm` and `global_asm` features.
- Removing the unstable book pages for `asm` and `global_asm`. The contents are moved to the [reference](https://github.com/rust-lang/reference/pull/1105) and [rust by example](https://github.com/rust-lang/rust-by-example/pull/1483).
- All links to these pages have been removed to satisfy the link checker. In a later PR these will be replaced with links to the reference or rust by example.
- Removing the automatic suggestion for using `llvm_asm!` instead of `asm!` if you're still using the old syntax, since it doesn't work anymore with `asm!` no longer being in the prelude. This only affects code that predates the old LLVM-style `asm!` being renamed to `llvm_asm!`.
- Updating `stdarch` and `compiler-builtins`.
- Updating all the tests.
r? `@joshtriplett`
replace dynamic library module with libloading
This PR deletes the `rustc_metadata::dynamic_lib` module in favor of the popular and better tested [`libloading` crate](https://github.com/nagisa/rust_libloading/).
We don't benefit from `libloading`'s symbol lifetimes since we end up leaking the loaded library in all cases, but the call-sites look much nicer by improving error handling and abstracting away some transmutes. We also can remove `rustc_metadata`'s direct dependencies on `libc` and `winapi`.
This PR also adds an exception for `libloading` (and its license) to tidy, so this will need sign-off from the compiler team.
They are also removed from the prelude as per the decision in
https://github.com/rust-lang/rust/issues/87228.
stdarch and compiler-builtins are updated to work with the new, stable
asm! and global_asm! macros.
Rollup of 7 pull requests
Successful merges:
- #90709 (Only shown relevant type params in E0283 label)
- #91551 (Allow for failure of subst_normalize_erasing_regions in const_eval)
- #91570 (Evaluate inline const pat early and report error if too generic)
- #91571 (Remove unneeded access to pretty printer's `s` field in favor of deref)
- #91610 (Link to rustdoc_json_types docs instead of rustdoc-json RFC)
- #91619 (Update cargo)
- #91630 (Add missing whitespace before disabled HTML attribute)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Update cargo
8 commits in 294967c53f0c70d598fc54ca189313c86c576ea7..40dc281755137ee804bc9b3b08e782773b726e44
2021-11-29 19:04:22 +0000 to 2021-12-06 21:54:44 +0000
- Unify the description of quiet flag (rust-lang/cargo#10168)
- Stabilize future-incompat-report (rust-lang/cargo#10165)
- Support abbreviating `--release` as `-r` (rust-lang/cargo#10133)
- doc: nudge towards simple version requirements (rust-lang/cargo#10158)
- Upgrade clap to 2.34.0 (rust-lang/cargo#10164)
- Treat EOPNOTSUPP the same as ENOTSUP when ignoring failed flock calls. (rust-lang/cargo#10157)
- Add note about RUSTFLAGS removal from build scripts. (rust-lang/cargo#10141)
- Make clippy happy (rust-lang/cargo#10139)
Use object crate for .rustc metadata generation
We already use the object crate for generating uncompressed .rmeta
metadata object files. This switches the generation of compressed
.rustc object files to use the object crate as well. These have
slightly different requirements in that .rmeta should be completely
excluded from any final compilation artifacts, while .rustc should
be part of shared objects, but not loaded into memory.
The primary motivation for this change is #90326: In LLVM 14, the
current way of setting section flags (and in particular, preventing
the setting of SHF_ALLOC) will no longer work. There are other ways
we could work around this, but switching to the object crate seems
like the most elegant, as we already use it for .rmeta, and as it
makes this independent of the codegen backend. In particular, we
don't need separate handling in codegen_llvm and codegen_gcc.
codegen_cranelift should be able to reuse the implementation as
well, though I have omitted that here, as it is not based on
codegen_ssa.
This change mostly extracts the existing code for .rmeta handling
to allow using it for .rustc as well, and adjusts the codegen
infrastructure to handle the metadata object file separately: We
no longer create a backend-specific module for it, and directly
produce the compiled module instead.
This does not `fix` #90326 by itself yet, as .llvmbc will need to be
handled separately.
r? `@nagisa`
We already use the object crate for generating uncompressed .rmeta
metadata object files. This switches the generation of compressed
.rustc object files to use the object crate as well. These have
slightly different requirements in that .rmeta should be completely
excluded from any final compilation artifacts, while .rustc should
be part of shared objects, but not loaded into memory.
The primary motivation for this change is #90326: In LLVM 14, the
current way of setting section flags (and in particular, preventing
the setting of SHF_ALLOC) will no longer work. There are other ways
we could work around this, but switching to the object crate seems
like the most elegant, as we already use it for .rmeta, and as it
makes this independent of the codegen backend. In particular, we
don't need separate handling in codegen_llvm and codegen_gcc.
codegen_cranelift should be able to reuse the implementation as
well, though I have omitted that here, as it is not based on
codegen_ssa.
This change mostly extracts the existing code for .rmeta handling
to allow using it for .rustc as well, and adjust the codegen
infrastructure to handle the metadata object file separately: We
no longer create a backend-specific module for it, and directly
produce the compiled module instead.
This does not fix#90326 by itself yet, as .llvmbc will need to be
handled separately.
Update Clippy dependencies
Clippy has two outdated dependencies, where one indirect dependency has been flagged by rustsec for dropping a lifetime. See [RUSTSEC-2020-0146](https://rustsec.org/advisories/RUSTSEC-2020-0146). This PR updates these dependencies.
With previous dependency updates, it was tried to prevent duplicates in the `Cargo.lock` file of rust-lang/rust. I've tried to keep this in mind with this update.
* Dependency `semver`
* Used in `src/tools/cargo/Cargo.toml` as version `1.0.3`
* Used in `src/tools/rust-analyzer/crates/project_model/Cargo.toml` as version `1`
* Updated in Clippy from `0.11` to `1.0` (Clippy usually defines the major and minor patch version). The `Cargo.lock` file lists `1.0.3` which is one patch version behind the most recent one but prevents a duplicate with cargo's pinned version.
* Dependency `cargo_metadata`
* Used in several tools as `0.14`
* Used in `src/tools/tidy` and `src/tools/rls` as `0.12`
* Updated in Clippy from `0.12` to `0.14`
All updates to the `Cargo.lock` have been done automatically by `x.py`.
There are still some tools with these outdated dependencies. Clippy didn't require any changes, and it would be likely that the others could also be updated without any problem. Let me know if I should try to update them as well 🙃.
Keep up the good work, whoever is reading this 🦀
---
For Clippy:
changelog: none
The rustc fork of rayon integrates with Cargo's jobserver to limit the
amount of parallelism. However, rustdoc's use case is concurrent I/O,
which is not CPU-heavy, so it should be able to use mainline rayon.
See this discussion [1] for more details.
[1]: https://github.com/rust-lang/rust/issues/90227#issuecomment-952468618
Note: I chose rayon 1.3.1 so that the rayon version used elsewhere in
the workspace does not change.
Add support for artifact size profiling
This adds support for profiling artifact file sizes (incremental compilation artifacts and query cache to begin with).
Eventually we want to track this in perf.rlo so we can ensure that file sizes do not change dramatically on each pull request.
This relies on support in measureme: https://github.com/rust-lang/measureme/pull/169. Once that lands we can update this PR to not point to a git dependency.
This was worked on together with `@michaelwoerister.`
r? `@wesleywiser`
Adopt let_else across the compiler
This performs a substitution of code following the pattern:
```
let <id> = if let <pat> = ... { identity } else { ... : ! };
```
To simplify it to:
```
let <pat> = ... { identity } else { ... : ! };
```
By adopting the `let_else` feature (cc #87335).
The PR also updates the syn crate because the currently used version of the crate doesn't support `let_else` syntax yet.
Note: Generally I'm the person who *removes* usages of unstable features from the compiler, not adds more usages of them, but in this instance I think it hopefully helps the feature get stabilized sooner and in a better state. I have written a [comment](https://github.com/rust-lang/rust/issues/87335#issuecomment-944846205) on the tracking issue about my experience and what I feel could be improved before stabilization of `let_else`.
Index and hash HIR as part of lowering
Part of https://github.com/rust-lang/rust/pull/88186
~Based on https://github.com/rust-lang/rust/pull/88880 (see merge commit).~
Once HIR is lowered, it is later indexed by the `index_hir` query and hashed for `crate_hash`. This PR moves those post-processing steps to lowering itself. As a side objective, the HIR crate data structure is refactored as an `IndexVec<LocalDefId, Option<OwnerInfo<'hir>>>` where `OwnerInfo` stores all the relevant information for an HIR owner.
r? `@michaelwoerister`
cc `@petrochenkov`
The syn crate has gained support for let_else syntax in version 1.0.76,
see https://github.com/dtolnay/syn/pull/1057 .
In the three instances that use let_else, we've sent code through an
attr macro, which would create compile errors when there was no
let_else support in syn. To avoid this, we ran
`cargo +nightly update -p syn` for updating the syn crate.
Wrapper for `-Z gcc-ld=lld` to invoke rust-lld with the correct flavor
This PR adds an `lld-wrapper` tool which is installed as `ld` and `ld64` in `lib\rustlib\<host_target>\bin\gcc-ld` directory and whose sole purpose is to invoke `rust-lld` in the parent directory with the correct flavor. Lld decides which flavor to use from either the first two commandline arguments or from the name of the executable (`ld` for GNU/ld flavor, `ld64` for Darwin/Macos/ld64 flavor and so on). Symbolic links could not be used as they are not supported by rustup and on Windows.
The wrapper replaces full copies of rust-lld which added some significant bloat. On UNIXish operating systems it exec rust-lld, on Windows it spawns it as a child process.
Fixes#88869.
r? ```@Mark-Simulacrum```
cc ```@nagisa``` ```@petrochenkov``` ```@1000teslas```
The wrapper is installed as `ld` and `ld64` in the `lib\rustlib\<host_target>\bin\gcc-ld`
directory and its sole purpose is to invoke `rust-lld` in the parent directory with
the correct flavor.
Add `deref_into_dyn_supertrait` lint.
Initial implementation of #89460. Resolves#89190.
Maybe also worth a beta backport if necessary.
r? `@nikomatsakis`
Added -Z randomize-layout flag
An implementation of #77316, it currently randomly shuffles the fields of `repr(rust)` types based on their `DefPathHash`
r? ``@eddyb``
Simplify lazy DefPathHash decoding by using an on-disk hash table.
This PR simplifies the logic around mapping `DefPathHash` values encountered during incremental compilation to valid `DefId`s in the current session. It is able to do so by using an on-disk hash table encoding that allows for looking up values directly, i.e. without deserializing the entire table.
The main simplification comes from not having to keep track of `DefPathHashes` being used during the compilation session.
Use a separate interner type for UniqueTypeId
Using symbol::Interner makes it very easy to mixup UniqueTypeId symbols
with the global interner. In fact the Debug implementation of
UniqueTypeId did exactly this.
Using a separate interner type also avoids prefilling the interner with
unused symbols and allow for optimizing the symbol interner for parallel
access without negatively affecting the single threaded module codegen.
Using symbol::Interner makes it very easy to mixup UniqueTypeId symbols
with the global interner. In fact the Debug implementation of
UniqueTypeId did exactly this.
Using a separate interner type also avoids prefilling the interner with
unused symbols and allow for optimizing the symbol interner for parallel
access without negatively affecting the single threaded module codegen.
Split rustc_mir
The `rustc_mir` crate is the second largest in the compiler.
This PR splits it up into 5 crates:
- rustc_borrowck;
- rustc_const_eval;
- rustc_mir_dataflow;
- rustc_mir_transform;
- rustc_monomorphize.
Pin bootstrap checksums and add a tool to update it automatically
⚠️⚠️ This is just a proactive hardening we're performing on the build system, and it's not prompted by any known compromise. If you're aware of security issues being exploited please [check out our responsible disclosure page](https://www.rust-lang.org/policies/security). ⚠️⚠️
---
This PR aims to improve Rust's supply chain security by pinning the checksums of the bootstrap compiler downloaded by `x.py`, preventing a compromised `static.rust-lang.org` from affecting building the compiler. The checksums are stored in `src/stage0.json`, which replaces `src/stage0.txt`. This PR also adds a tool to automatically update the bootstrap compiler.
The changes in this PR were originally discussed in [Zulip](https://zulip-archive.rust-lang.org/stream/241545-t-release/topic/pinning.20stage0.20hashes.html).
## Potential attack
Before this PR, an attacker who wanted to compromise the bootstrap compiler would "just" need to:
1. Gain write access to `static.rust-lang.org`, either by compromising DNS or the underlying storage.
2. Upload compromised binaries and corresponding `.sha256` files to `static.rust-lang.org`.
There is no signature verification in `x.py` as we don't want the build system to depend on GPG. Also, since the checksums were not pinned inside the repository, they were downloaded from `static.rust-lang.org` too: this only protected from accidental changes in `static.rust-lang.org` that didn't change the `*.sha256` files. The attack would allow the attacker to compromise past and future invocations of `x.py`.
## Mitigations introduced in this PR
This PR adds pinned checksums for all the bootstrap components in `src/stage0.json` instead of downloading the checksums from `static.rust-lang.org`. This changes the attack scenario to:
1. Gain write access to `static.rust-lang.org`, either by compromising DNS or the underlying storage.
2. Upload compromised binaries to `static.rust-lang.org`.
3. Land a (reviewed) change in the `rust-lang/rust` repository changing the pinned hashes.
Even with a successful attack, existing clones of the Rust repository won't be affected, and once the attack is detected reverting the pinned hashes changes should be enough to be protected from the attack. This also enables further mitigations to be implemented in following PRs, such as verifying signatures when pinning new checksums (removing the trust on first use aspect of this PR) and adding a check in CI making sure a PR updating the checksum has not been tampered with (see the future improvements section).
## Additional changes
There are additional changes implemented in this PR to enable the mitigation:
* The `src/stage0.txt` file has been replaced with `src/stage0.json`. The reasoning for the change is that there is existing tooling to read and manipulate JSON files compared to the custom format we were using before, and the slight challenge of manually editing JSON files (no comments, no trailing commas) are not a problem thanks to the new `bump-stage0`.
* A new tool has been added to the repository, `bump-stage0`. When invoked, the tool automatically calculates which release should be used as the bootstrap compiler given the current version and channel, gathers all the relevant checksums and updates `src/stage0.json`. The tool can be invoked by running:
```
./x.py run src/tools/bump-stage0
```
* Support for downloading releases from `https://dev-static.rust-lang.org` has been removed, as it's not possible to verify checksums there (it's customary to replace existing artifacts there if a rebuild is warranted). This will require a change to the release process to avoid bumping the bootstrap compiler on beta before the stable release.
## Future improvements
* Add signature verification as part of `bump-stage0`, which would require the attacker to also obtain the release signing keys in order to successfully compromise the bootstrap compiler. This would be fine to add now, as the burden of installing the tool to verify signatures would only be placed on whoever updates the bootstrap compiler, instead of everyone compiling Rust.
* Add a check on CI that ensures the checksums in `src/stage0.json` are the expected ones. If a PR changes the stage0 file CI should also run the `bump-stage0` tool and fail if the output in CI doesn't match the committed file. This prevents the PR author from tweaking the output of the tool manually, which would otherwise be close to impossible for a human to detect.
* Automate creating the PRs bumping the bootstrap compiler, by setting up a scheduled job in GitHub Actions that runs the tool and opens a PR.
* Investigate whether a similar mitigation can be done for "download from CI" components like the prebuilt LLVM.
r? `@Mark-Simulacrum`
Warn when [T; N].into_iter() is ambiguous in the new edition.
Fixes https://github.com/rust-lang/rust/issues/88475
In https://github.com/rust-lang/rust/issues/88475, a situation was found where `[T; N].into_iter()` becomes *ambiguous* in the new edition. This is different than the case where `(&[T; N]).into_iter()` resolves differently, which was the only case handled by the `array_into_iter` lint. This is almost identical to the new-traits-in-the-prelude problem. Effectively, due to the array-into-iter hack disappearing in Rust 2021, we effectively added `IntoIterator` to the 'prelude' in Rust 2021 specifically for arrays.
This modifies the prelude collisions lint to detect that case and emit a `array_into_iter` lint in that case.
Instead of updating global state to mark attributes as used,
we now explicitly emit a warning when an attribute is used in
an unsupported position. As a side effect, we are to emit more
detailed warning messages (instead of just a generic "unused" message).
`Session.check_name` is removed, since its only purpose was to mark
the attribute as used. All of the callers are modified to use
`Attribute.has_name`
Additionally, `AttributeType::AssumedUsed` is removed - an 'assumed
used' attribute is implemented by simply not performing any checks
in `CheckAttrVisitor` for a particular attribute.
We no longer emit unused attribute warnings for the `#[rustc_dummy]`
attribute - it's an internal attribute used for tests, so it doesn't
mark sense to treat it as 'unused'.
With this commit, a large source of global untracked state is removed.
Update the backtrace crate in libstd
This commit updates the backtrace crate in libstd now that dependencies
have been updated to use `memchr` from the standard library as well.
This is mostly just making sure deps are up-to-date and have all the
latest-and-greatest fixes and such.
Closesrust-lang/backtrace-rs#432
This commit updates the backtrace crate in libstd now that dependencies
have been updated to use `memchr` from the standard library as well.
This is mostly just making sure deps are up-to-date and have all the
latest-and-greatest fixes and such.
Closesrust-lang/backtrace-rs#432
Unbox mutexes, condvars and rwlocks on hermit
[RustyHermit](https://github.com/hermitcore/rusty-hermit) provides now movable synchronization primitives and we are able to unbox mutexes and condvars.
Matthew's work on improving NLL's "higher-ranked subtype error"s
This PR rebases `@matthewjasper's` [branch](https://github.com/matthewjasper/rust/tree/nll-hrtb-errors) which has great work to fix the obscure higher-ranked subtype errors that are tracked in #57374.
These are a blocker to turning full NLLs on, and doing some internal cleanups to remove some of the old region code.
The goal is so `@nikomatsakis` can take a look at this early, and I'll then do my best to help do the changes and followup work to land this work, and move closer to turning off the migration mode.
I've only updated the branch and made it compile, removed a warning or two.
r? `@nikomatsakis`
(Here's the [zulip topic to discuss this](https://rust-lang.zulipchat.com/#narrow/stream/122657-t-compiler.2Fwg-nll/topic/.2357374.3A.20improving.20higher-ranked.20subtype.20errors.20via.20.2386700) that Niko wanted)
Update cargo
8 commits in b51439fd8b505d4800a257acfecf3c69f81e35cf..e96bdb0c3d0a418e7fcd7fbd69be08abf830b4bc
2021-08-09 18:40:05 +0000 to 2021-08-17 22:58:47 +0000
- Support using rustbot to ping the Windows group (rust-lang/cargo#9802)
- Show information about abnormal `fix` errors. (rust-lang/cargo#9799)
- Bump jobserver. (rust-lang/cargo#9798)
- Render build-std web links as hyperlinks (rust-lang/cargo#9795)
- Teach cargo to failfast on recursive/corecursive aliases (rust-lang/cargo#9791)
- Fix value-after-table error with profiles. (rust-lang/cargo#9789)
- Fix plugin registrar change. (rust-lang/cargo#9790)
- Ability to specify the output name for a bin target different from the crate name (rust-lang/cargo#9627)
Update `polonius-engine` to 0.13.0
This PR updates the use of `polonius-engine` to the recently released 0.13.0:
- this version renamed a lot of relations to match the current terminology
- "illegal subset relationships errors" (AKA "subset errors" or "universal region errors" in rustc parlance) have been implemented in all variants, and therefore the `Hybrid` variant can be the rustc default once again
- some of the blessed expectations were updated: new tests have been added since the last time I updated the tests, diagnostics have changed, etc.
In particular:
- a few tests had trivial expectations changes such as basic diagnostics changes for the migrate-mode and full NLLs
- others were recursion and lengths limits which emits a file, and under the polonius compare-mode, the folder has a different name
- a few tests were ignored in the NLL compare-mode for reasons that obviously also apply to Polonius
- some diagnostics were unified so that older expectations no longer made sense: the NLL and Polonius outputs were identical.
- in a few cases Polonius gets a chance to emit more errors than NLLs
A few tests in the compare-mode still are super slow and trigger the 60s warning, or OOM rustc during fact generation, and I've detailed these [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/186049-t-compiler.2Fwg-polonius/topic/Challenges.20for.20move.2Finit.2C.20liveness.2C.20and.20.60Location.3A.3AAll.60):
- `src/test/ui/numbers-arithmetic/saturating-float-casts.rs` -> OOM during rustc fact generation
- `src/test/ui/numbers-arithmetic/num-wrapping.rs`
- `src/test/ui/issues/issue-72933-match-stack-overflow.rs`
- `src/test/ui/issues/issue-74564-if-expr-stack-overflow.rs`
- `src/test/ui/repr/repr-no-niche.rs`
In addition, 2 tests don't currently pass and I didn't want to bless them now: they deal with HRTBs and miss errors that NLLs emit. We're currently trying to see if we need chalk to deal with HRTB errors (as we thought we would have to) but during the recent sprint, we discovered that we may be able to detect some of these errors in a way that resembles subset errors:
- `ui/hrtb/hrtb-just-for-static.rs` -> 3 errors in NLL, 2 in polonius: a missing error about HRTB + needing to outlive 'static
- `ui/issues/issue-26217.rs` -> missing HRTB that makes the test compile instead of emitting an error
We'll keep talking about this at the next sprint as well.
cc `@rust-lang/wg-polonius` r? `@nikomatsakis`
Improve non_fmt_panics suggestion based on trait impls.
This improves the non_fmt_panics lint suggestions by checking first which trait (Display or Debug) are actually implemented on the type.
Fixes https://github.com/rust-lang/rust/issues/87313
Fixes https://github.com/rust-lang/rust/issues/87999
Before:
```
help: add a "{}" format string to Display the message
|
2 | panic!("{}", Some(1));
| +++++
help: or use std::panic::panic_any instead
|
2 | std::panic::panic_any(Some(1));
| ~~~~~~~~~~~~~~~~~~~~~
```
After:
```
help: add a "{:?}" format string to use the Debug implementation of `Option<i32>`
|
2 | panic!("{:?}", Some(1));
| +++++++
help: or use std::panic::panic_any instead
|
2 | std::panic::panic_any(Some(1));
| ~~~~~~~~~~~~~~~~~~~~~
```
r? `@estebank`
Uplift the invalid_atomic_ordering lint from clippy to rustc
This is mostly just a rebase of https://github.com/rust-lang/rust/pull/79654; I've copy/pasted the text from that PR below.
r? `@lcnr` since you reviewed the last one, but feel free to reassign.
---
This is an implementation of https://github.com/rust-lang/compiler-team/issues/390.
As mentioned, in general this turns an unconditional runtime panic into a (compile time) lint failure. It has no false positives, and the only false negatives I'm aware of are if `Ordering` isn't specified directly and is comes from an argument/constant/whatever.
As a result of it having no false positives, and the alternative always being strictly wrong, it's on as deny by default. This seems right.
In the [zulip stream](https://rust-lang.zulipchat.com/#narrow/stream/233931-t-compiler.2Fmajor-changes/topic/Uplift.20the.20.60invalid_atomic_ordering.60.20lint.20from.20clippy/near/218483957) `@joshtriplett` suggested that lang team should FCP this before landing it. Perhaps libs team cares too?
---
Some notes on the code for reviewers / others below
## Changes from clippy
The code is changed from [the implementation in clippy](68cf94f6a6/clippy_lints/src/atomic_ordering.rs) in the following ways:
1. Uses `Symbols` and `rustc_diagnostic_item`s instead of string literals.
- It's possible I should have just invoked Symbol::intern for some of these instead? Seems better to use symbol, but it did require adding several.
2. The functions are moved to static methods inside the lint struct, as a way to namespace them.
- There's a lot of other code in that file — which I picked as the location for this lint because `@jyn514` told me that seemed reasonable.
3. Supports unstable AtomicU128/AtomicI128.
- I did this because it was almost easier to support them than not — not supporting them would have (ideally) required finding a way not to give them a `rustc_diagnostic_item`, which would have complicated an already big macro.
- These don't have tests since I wasn't sure if/how I should make tests conditional on whether or not the target has the atomic... This is to a certain extent an issue of 64bit atomics too, but 128-bit atomics are much less common. Regardless, the existing tests should be *more* than thorough enough here.
4. Minor changes like:
- grammar tweaks ("loads cannot have `Release` **and** `AcqRel` ordering" => "loads cannot have `Release` **or** `AcqRel` ordering")
- function renames (`match_ordering_def_path` => `matches_ordering_def_path`),
- avoiding clippy-specific helper methods that don't exist in rustc_lint and didn't seem worth adding for this case (for example `cx.struct_span_lint` vs clippy's `span_lint_and_help` helper).
## Potential issues
(This is just about the code in this PR, not conceptual issues with the lint or anything)
1. I'm not sure if I should have used a diagnostic item for `Ordering` and its variants (I couldn't figure out how really, so if I should do this some pointers would be appreciated).
- It seems possible that failing to do this might possibly mean there are more cases this lint would miss, but I don't really know how `match_def_path` works and if it has any pitfalls like that, so maybe not.
2. I *think* I deprecated the lint in clippy (CC `@flip1995` who asked to be notified about clippy changes in the future in [this comment](https://github.com/rust-lang/rust/pull/75671#issuecomment-718731659)) but I'm not sure if I need to do anything else there.
- I'm kind of hoping CI will catch if I missed anything, since `x.py test src/tools/clippy` fails with a lot of errors with and without my changes (and is probably a nonsense command regardless). Running `cargo test` from src/tools/clippy also fails with unrelated errors that seem like refactorings that didnt update clippy? So, honestly no clue.
3. I wasn't sure if the description/example I gave good. Hopefully it is. The example is less thorough than the one from clippy here: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_atomic_ordering. Let me know if/how I should change it if it needs changing.
4. It pulls in the `if_chain` crate. This crate was already used in clippy, and seems like it's used elsewhere in rustc, but I'm willing to rewrite it to not use this if needed (I'd prefer not to, all things being equal).
- Deprecate clippy::invalid_atomic_ordering
- Use rustc_diagnostic_item for the orderings in the invalid_atomic_ordering lint
- Reduce code duplication
- Give up on making enum variants diagnostic items and just look for
`Ordering` instead
I ran into tons of trouble with this because apparently the change to
store HIR attrs in a side table also gave the DefIds of the
constructor instead of the variant itself. So I had to change
`matches_ordering` to also check the grandparent of the defid as well.
- Rename `atomic_ordering_x` symbols to just the name of the variant
- Fix typos in checks - there were a few places that said "may not be
Release" in the diagnostic but actually checked for SeqCst in the lint.
- Make constant items const
- Use fewer diagnostic items
- Only look at arguments after making sure the method matches
This prevents an ICE when there aren't enough arguments.
- Ignore trait methods
- Only check Ctors instead of going through `qpath_res`
The functions take values, so this couldn't ever be anything else.
- Add if_chain to allowed dependencies
- Fix grammar
- Remove unnecessary allow
STD support for the ESP-IDF framework
Dear all,
This PR is implementing libStd support for the [ESP-IDF](https://github.com/espressif/esp-idf) newlib-based framework, which is the open source SDK provided by Espressif for their MCU family (esp32, esp32s2, esp32c3 and all other forthcoming ones).
Note that this PR has a [sibling PR](https://github.com/rust-lang/libc/pull/2310) against the libc crate, which implements proper declarations for all ESP-IDF APIs which are necessary for libStd support.
# Implementation approach
The ESP-IDF framework - despite being bare metal - offers a relatively complete POSIX API based on newlib. `pthread`, BSD sockets, file descriptors, and even a small file-system VFS layer. Perhaps the only significant exception is the lack of support for processes, which is to be expected of course on bare metal.
Therefore, the libStd support is implemented as a set of (hopefully small) changes to the `sys/unix` family of modules, in the form of conditional-compilation branches based either on `target_os = "espidf"` or in a couple of cases - based on `target_env = "newlib"` (the latter was already there actually and is not part of this patch).
The PR also contains two new targets:
- `riscv32imc-esp-espidf`
- `riscv32imac-esp-espidf`
... which are essentially copies of `riscv32imc-unknown-none-elf` and `riscv32imac-unknown-none-elf`, but enriched with proper `linker`, `linker_flavor`, `families`, `os`, `env` etc. specifications so that (a) the proper conditional compilation branches in libStd are selected when compiling with these targets and (b) the correct linker is used.
Since support for atomics is a precondition for libStd, the `riscv32imc-esp-espidf` target additionally is configured in such a way, so as to emit libcalls to the `__sync*` & `__atomic*` GCC functions, which are already implemented in the ESP-IDF framework. If this modification is not acceptable, we can also live with only the `riscv32imac-esp-espidf` target as well. While the RiscV chips of Espressif lack native atomics support, the relevant instructions are transparently emulated in the ESP-IDF framework using invalid instruction trap. This modification was implemented specifically with Rust support in mind.
# Target maintainers
In case this PR eventually gets merged, you can list myself as a Target Maintainer.
More importantly, Espressif (the chip vendor) is now actively involved and [embracing](https://github.com/espressif/rust-esp32-example/blob/main/docs/rust-on-xtensa.md) all [Rust-related efforts](https://github.com/esp-rs) which were originally a community effort. In light of that, I suppose `@MabezDev` - who initiated the Rust-on-Espressif efforts back in time and who now works for Espressif won't object to being listed as a maintainer as well.
**EDIT:** I was hinted (thanks, `@Urgau)` that answering the Tier 3 policy explicitly might be helpful. Answers below.
# Tier 3 Target Policy - answers
> A proposed target or target-specific patch that substantially changes code shared with other targets (not just target-specific code) must be reviewed and approved by the appropriate team for that shared code before acceptance.
Hopefully, the changes introduced by the ESP-IDF libStd support are rather on the small side. They are completely contained within the `sys/unix` set of modules (that is, aside from the obviously necessary one-liners in the `unwind` crate and in `build.rs`).
> A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
`@ivmarkov`
`@MabezDev`
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
The two introduced targets follow as much as possible the naming conventions of the other targets. I.e. taking the bare-metal `riscv32imac_unknown_none_elf` as a base:
* The name of the new target was derived by replacing `none` with `espidf` to designate the `target_os`.
* `_elf` was removed, as the non-bare metal targets seem not to have it
* `-newlib` was deliberately NOT added at the end, as I believe the chance of having two simultaneously active separate targets for the ESP-IDF framework with different C libraries (say, newlib vs musl) is way too small
* Finally, we replaced the middle `unknown` with `esp` which is kind of the name of the whole chipset MCU family (and abbreviation from Espressif which is too long). It will stay `esp` for all RiscV32-based MCUs of the company, as they all use the riscv32imc instruction set. By necessity however (disambiguation), it will be `esp32` or `esp32s2` or `esp32s3` for the Xtensa-based MCUs as all of these have their own variation of the Xtensa architecture. (The Xtensa targets are not part of this PR, even though they would use 1:1 the same LibStd implementation provided here, as they depend on the upstreaming of the Xtensa architecture support in LLVM; this upstreaming this is currently in progress.)
There was also a preceding discussion on the topic [here](https://github.com/espressif/rust-esp32-example/issues/14).
> Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
We are explicitly putting an `-espidf` suffix to designate that the target is *specifically* for Rust + ESP-IDF
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
Agreed.
> The target must not introduce license incompatibilities.
To the best of our knowledge, it doesn't.
> Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
MIT + Apache 2.0
> The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
Requirements are not changed for any other target.
> If the target supports building host tools (such as rustc or cargo), those host tools must not depend on proprietary (non-FOSS) libraries, other than ordinary runtime libraries supplied by the platform and commonly used by other binaries built for the target. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
The targets are for bare-metal environment which is not hosting build tools or a compiler.
> Targets should not require proprietary (non-FOSS) components to link a functional binary or library.
The linker used by the targets is the GCC linker from the GCC toolchain cross-compiled for riscv. GNU GPL.
> "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
> This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
Agreed.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
The targets implement libStd almost in its entirety, except for the missing support for process, as this is a bare metal platform. The process `sys\unix` module is currently stubbed to return "not implemented" errors.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running tests (even if they do not pass), the documentation must explain how to run tests for the target, using emulation if possible or dedicated hardware if necessary.
Target does not (yet) support running tests. We would gladly provide all documentation how to build for the target (where?). It is currently hosted in this [README.md](https://github.com/ivmarkov/rust-esp32-std-hello) file, but will likely be moved to the [esp-rs](https://github.com/esp-rs) organization. Since the build for the target is driven by cargo and [all other tooling is downloaded automatically during the build](https://github.com/esp-rs/esp-idf-sys/blob/master/build.rs), there is no need for extensive documentation.
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
Agreed.
> Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
Agreed.
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
To the best of our knowledge, we believe we are not breaking any other target (be it tier 1, 2 or 3).
> In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
To the best of our knowledge, we have not introduced any unconditional use of a feature that affects any other target.
> If a tier 3 target stops meeting these requirements, or the target maintainers no longer have interest or time, or the target shows no signs of activity and has not built for some time, or removing the target would improve the quality of the Rust codebase, we may post a PR to remove it; any such PR will be CCed to the target maintainers (and potentially other people who have previously worked on the target), to check potential interest in improving the situation.
Agreed.
