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2021-12-06Auto merge of #91284 - t6:freebsd-riscv64, r=Amanieubors-0/+1
Add support for riscv64gc-unknown-freebsd For https://doc.rust-lang.org/nightly/rustc/target-tier-policy.html#tier-3-target-policy: * 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.) For all Rust targets on FreeBSD, it's [rust@FreeBSD.org](mailto:rust@FreeBSD.org). * 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. Done. * 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. Done * 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. Done. * The target must not introduce license incompatibilities. Done. * Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0). Fine with me. * 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. Done. * 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. Done. * Targets should not require proprietary (non-FOSS) components to link a functional binary or library. Done. * "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. Fine with me. * 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. Ok. * 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. Ok. * 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. std is implemented. * 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. Building is possible the same way as other Rust on FreeBSD targets. * 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. Ok. * 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. Ok. * 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. Ok. * 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. Ok.
2021-11-27Add riscv64gc-unknown-freebsdTobias Kortkamp-0/+1
2021-11-18Auto merge of #90382 - alexcrichton:wasm64-libstd, r=joshtriplettbors-1/+103
std: Get the standard library compiling for wasm64 This commit goes through and updates various `#[cfg]` as appropriate to get the wasm64-unknown-unknown target behaving similarly to the wasm32-unknown-unknown target. Most of this is just updating various conditions for `target_arch = "wasm32"` to also account for `target_arch = "wasm64"` where appropriate. This commit also lists `wasm64` as an allow-listed architecture to not have the `restricted_std` feature enabled, enabling experimentation with `-Z build-std` externally. The main goal of this commit is to enable playing around with `wasm64-unknown-unknown` externally via `-Z build-std` in a way that's similar to the `wasm32-unknown-unknown` target. These targets are effectively the same and only differ in their pointer size, but wasm64 is much newer and has much less ecosystem/library support so it'll still take time to get wasm64 fully-fledged.
2021-11-15Stabilize -Z strip as -C stripJosh Triplett-0/+16
Leave -Z strip available temporarily as an alias, to avoid breaking cargo until cargo transitions to using -C strip. (If the user passes both, the -C version wins.)
2021-11-10Add a missing doc linkAlex Crichton-0/+1
2021-11-10Update src/doc/rustc/src/platform-support.mdAlex Crichton-1/+1
Co-authored-by: Josh Triplett <josh@joshtriplett.org>
2021-11-10Add target documentation for wasm64-unknown-unknownAlex Crichton-0/+101
2021-11-10Update platform support docsAlex Crichton-1/+1
2021-11-02Add a template for target-specific documentationJosh Triplett-2/+56
2021-11-02Point to platform-support/ for target-specific documentationJosh Triplett-0/+6
Explain that target-specific documentation should appear in a subdirectory of platform-support, with a link from the target's entry on the platform-support page.
2021-11-02Clarify documentation about running binariesJosh Triplett-3/+3
The requirement for target documentation talks about "running tests", but tier 3 targets often don't support running the full testsuite, and in practice the documentation for how to run an individual binary may be more useful. Change "running tests" to "running binaries, or running tests".
2021-11-02Clarify dependency requirements in the face of cross-compilationJosh Triplett-11/+13
The requirement on dependencies was phrased in terms of "host tools", but it was also intended to apply equally to targets that only support cross-compilation. Only the exception (for libraries commonly needed for binaries on the target) was intended to apply to host tools. Reword the requirement to talk about the dependencies required for "compiling, linking,and emitting functional binaries, libraries, or other code for the target", rather than generically in terms of dependencies for rustc/cargo. This doesn't change the net effect of the requirements, since other requirements already stated that the target can't make the Rust toolchain depend on proprietary libraries. However, this should make the requirements clearer.
2021-11-02Clarify how to quote and respond to the target tier policy requirementsJosh Triplett-2/+4
Several times, people have seemed unclear on how to respond to some of the policy requirements, particularly those that just state things the target developers must *not* do (e.g. not posting to PRs that break the target). Add a note that such requirements just need acknowledgement, nothing more. Make quoting and responding a "must" rather than an "is encouraged to", since it's easier to review the requirements that way.
2021-10-31Auto merge of #89062 - mikeleany:new-target, r=cjgillotbors-0/+78
Add new tier 3 target: `x86_64-unknown-none` Adds support for compiling OS kernels or other bare-metal applications for the x86-64 architecture. Below are details on how this target meets the requirements for tier 3: > 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.) I would be willing to be a target maintainer, though I would appreciate if others volunteered to help with that as well. > 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. Uses the same naming as the LLVM target, and the same convention as many other bare-metal targets. > 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. I don't believe there is any ambiguity here. > 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. I don't see any legal issues here. > The target must not introduce license incompatibilities. > Anything added to the Rust repository must be under the standard Rust license (MIT OR 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. >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. > Targets should not require proprietary (non-FOSS) components to link a functional binary or library. > "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. I see no issues with any of the above. > 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. Only relevant to those making approval decisions. > 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. `core` and `alloc` can be used. `std` cannot be used as this is a bare-metal target. > 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. Use `--target=x86_64-unknown-none-elf` option to cross compile, just like any target. The target does not support running tests. > 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. > 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. I don't foresee this being a problem. > 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. > 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. No other targets should be affected by the pull request.
2021-10-26Add documentation for LLVM CFI supportRamon de C Valle-17/+23
This commit adds initial documentation for LLVM Control Flow Integrity (CFI) support to the Rust compiler (see #89652 and #89653).
2021-10-13Unlinkify email address to satisfy linkcheckerJosh Triplett-1/+1
The linkchecker doesn't seem happy with links to email addresses.
2021-10-13Documentation fixes.Mike Leany-2/+3
Fix broken link to target documentation. Also fix formatting of developer list.
2021-10-13x86_64-unknown-none: Add target documentationJosh Triplett-1/+77
In particular, document the default properties and assumptions of code built for the target. (Work on this target sponsored by Profian.)
2021-10-13Rename x86_64-unknown-none-elf to x86_64-unknown-noneJosh Triplett-1/+1
Most Rust freestanding/bare-metal targets use just `-unknown-none` here, including aarch64-unknown-none, mipsel-unknown-none, and the BPF targets. The *only* target using `-unknown-none-elf` is RISC-V. The underlying toolchain doesn't care; LLVM accepts both `x86_64-unknown-none` and `x86_64-unknown-none-elf`. In addition, there's a long history of embedded x86 targets with varying definitions for the `elf` suffix; on some of those embedded targets, `elf` implied the inclusion of a C library based on newlib or similar. Using `x86_64-unknown-none` avoids any potential ambiguity there. (Work on this target sponsored by Profian.)
2021-10-13Add `x86_64-unknown-none-elf` to `platform-support.md`.Mike Leany-0/+1
2021-10-10Auto merge of #88952 - skrap:add-armv7-uclibc, r=nagisabors-0/+67
Add new tier-3 target: armv7-unknown-linux-uclibceabihf This change adds a new tier-3 target: armv7-unknown-linux-uclibceabihf This target is primarily used in embedded linux devices where system resources are slim and glibc is deemed too heavyweight. Cross compilation C toolchains are available [here](https://toolchains.bootlin.com/) or via [buildroot](https://buildroot.org). The change is based largely on a previous PR #79380 with a few minor modifications. The author of that PR was unable to push the PR forward, and graciously allowed me to take it over. Per the [target tier 3 policy](https://github.com/rust-lang/rfcs/blob/master/text/2803-target-tier-policy.md), I volunteer to be the "target maintainer". This is my first PR to Rust itself, so I apologize if I've missed things!
2021-10-07Rollup merge of #89082 - smoelius:master, r=kennytmJubilee-1/+35
Implement #85440 (Random test ordering) This PR adds `--shuffle` and `--shuffle-seed` options to `libtest`. The options are similar to the [`-shuffle` option](https://github.com/golang/go/blob/c894b442d1e5e150ad33fa3ce13dbfab1c037b3a/src/testing/testing.go#L1482-L1499) that was recently added to Go. Here are the relevant parts of the help message: ``` --shuffle Run tests in random order --shuffle-seed SEED Run tests in random order; seed the random number generator with SEED ... By default, the tests are run in alphabetical order. Use --shuffle or set RUST_TEST_SHUFFLE to run the tests in random order. Pass the generated "shuffle seed" to --shuffle-seed (or set RUST_TEST_SHUFFLE_SEED) to run the tests in the same order again. Note that --shuffle and --shuffle-seed do not affect whether the tests are run in parallel. ``` Is an RFC needed for this?
2021-10-06Rollup merge of #89324 - yoshuawuyts:hardware-parallelism, r=m-ou-seManish Goregaokar-2/+2
Rename `std::thread::available_conccurrency` to `std::thread::available_parallelism` _Tracking issue: https://github.com/rust-lang/rust/issues/74479_ This PR renames `std::thread::available_conccurrency` to `std::thread::available_parallelism`. ## Rationale The API was initially named `std::thread::hardware_concurrency`, mirroring the [C++ API of the same name](https://en.cppreference.com/w/cpp/thread/thread/hardware_concurrency). We eventually decided to omit any reference to the word "hardware" after [this comment](https://github.com/rust-lang/rust/pull/74480#issuecomment-662045841). And so we ended up with `available_concurrency` instead. --- For a talk I was preparing this week I was reading through ["Understanding and expressing scalable concurrency" (A. Turon, 2013)](http://aturon.github.io/academic/turon-thesis.pdf), and the following passage stood out to me (emphasis mine): > __Concurrency is a system-structuring mechanism.__ An interactive system that deals with disparate asynchronous events is naturally structured by division into concurrent threads with disparate responsibilities. Doing so creates a better fit between problem and solution, and can also decrease the average latency of the system by preventing long-running computations from obstructing quicker ones. > __Parallelism is a resource.__ A given machine provides a certain capacity for parallelism, i.e., a bound on the number of computations it can perform simultaneously. The goal is to maximize throughput by intelligently using this resource. For interactive systems, parallelism can decrease latency as well. _Chapter 2.1: Concurrency is not Parallelism. Page 30._ --- _"Concurrency is a system-structuring mechanism. Parallelism is a resource."_ — It feels like this accurately captures the way we should be thinking about these APIs. What this API returns is not "the amount of concurrency available to the program" which is a property of the program, and thus even with just a single thread is effectively unbounded. But instead it returns "the amount of _parallelism_ available to the program", which is a resource hard-constrained by the machine's capacity (and can be further restricted by e.g. operating systems). That's why I'd like to propose we rename this API from `available_concurrency` to `available_parallelism`. This still meets the criteria we previously established of not attempting to define what exactly we mean by "hardware", "threads", and other such words. Instead we only talk about "concurrency" as an abstract resource available to our program. r? `@joshtriplett`
2021-10-06add platform support details file for armv7-unknown-linux-uclibcJonah Petri-0/+66
2021-10-06Add new target armv7-unknown-linux-uclibceabihfYannick Koehler-0/+1
Co-authored-by: Jonah Petri <jonah@petri.us>
2021-10-05Add tracking issueSamuel E. Moelius III-2/+4
2021-10-04Add documentationSamuel E. Moelius III-1/+33
2021-10-01Rollup merge of #88847 - oliverbr:master, r=steveklabnikManish Goregaokar-2/+2
platform-support.md: correct ARMv7+MUSL platform triple notes This PR fixes two minor inconsistencies in the platform support list. - use "with MUSL" suffix for "armv7-unknown-linux-musleabi" - add "hardfloat" suffix for "armv7-unknown-linux-musleabihf" r? `@steveklabnik`
2021-10-01Rollup merge of #88820 - hlopko:add_pie_relocation_model, r=petrochenkovManish Goregaokar-0/+4
Add `pie` as another `relocation-model` value MCP: https://github.com/rust-lang/compiler-team/issues/461
2021-10-01Add `pie` as another `relocation-model` valueMarcel Hlopko-0/+4
2021-09-28Rename `std::thread::available_onccurrency` to ↵Yoshua Wuyts-2/+2
`std::thread::available_parallelism`
2021-09-28Add SOLID targetsTomoaki Kawada-0/+69
SOLID[1] is an embedded development platform provided by Kyoto Microcomputer Co., Ltd. This commit introduces a basic Tier 3 support for SOLID. # New Targets The following targets are added: - `aarch64-kmc-solid_asp3` - `armv7a-kmc-solid_asp3-eabi` - `armv7a-kmc-solid_asp3-eabihf` SOLID's target software system can be divided into two parts: an RTOS kernel, which is responsible for threading and synchronization, and Core Services, which provides filesystems, networking, and other things. The RTOS kernel is a μITRON4.0[2][3]-derived kernel based on the open-source TOPPERS RTOS kernels[4]. For uniprocessor systems (more precisely, systems where only one processor core is allocated for SOLID), this will be the TOPPERS/ASP3 kernel. As μITRON is traditionally only specified at the source-code level, the ABI is unique to each implementation, which is why `asp3` is included in the target names. More targets could be added later, as we support other base kernels (there are at least three at the point of writing) and are interested in supporting other processor architectures in the future. # C Compiler Although SOLID provides its own supported C/C++ build toolchain, GNU Arm Embedded Toolchain seems to work for the purpose of building Rust. # Unresolved Questions A μITRON4 kernel can support `Thread::unpark` natively, but it's not used by this commit's implementation because the underlying kernel feature is also used to implement `Condvar`, and it's unclear whether `std` should guarantee that parking tokens are not clobbered by other synchronization primitives. # Unsupported or Unimplemented Features Most features are implemented. The following features are not implemented due to the lack of native support: - `fs::File::{file_attr, truncate, duplicate, set_permissions}` - `fs::{symlink, link, canonicalize}` - Process creation - Command-line arguments Backtrace generation is not really a good fit for embedded targets, so it's intentionally left unimplemented. Unwinding is functional, however. ## Dynamic Linking Dynamic linking is not supported. The target platform supports dynamic linking, but enabling this in Rust causes several problems. - The linker invocation used to build the shared object of `std` is too long for the platform-provided linker to handle. - A linker script with specific requirements is required for the compiled shared object to be actually loadable. As such, we decided to disable dynamic linking for now. Regardless, the users can try to create shared objects by manually invoking the linker. ## Executable Building an executable is not supported as the notion of "executable files" isn't well-defined for these targets. [1] https://solid.kmckk.com/SOLID/ [2] http://ertl.jp/ITRON/SPEC/mitron4-e.html [3] https://en.wikipedia.org/wiki/ITRON_project [4] https://toppers.jp/
2021-09-17doc/platform-support: Add documentation for m68k-unknown-linux-gnuJohn Paul Adrian Glaubitz-0/+97
2021-09-17doc/platform-support.md: Add m68k-unknown-linux-gnu as Tier 3 targetJohn Paul Adrian Glaubitz-0/+1
2021-09-11correct ARM+MUSL notesoliverbr-2/+2
- use "with MUSL" style where applicable - add "hardfloat" suffix for "armv7-unknown-linux-musleabihf"
2021-08-31ARMv6K Nintendo 3DS Tier 3 target addedMeziu-0/+1
2021-08-30update rustc cmdargs markdown sectionHTG-YT-1/+1
2021-08-24Document `force-warn`inquisitivecrystal-12/+27
Co-authored-by: Mark Rousskov <mark.simulacrum@gmail.com>
2021-08-16Rollup merge of #87677 - amalik18:issue-2788-fix, r=pietroalbiniMara Bos-0/+4
Adding explicit notice of lack of documentation for Tier 2 Platforms Fixing: https://github.com/rust-lang/rustup/issues/2788
2021-08-12Auto merge of #87666 - ivmarkov:master, r=Amanieubors-0/+1
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.
2021-08-11Rollup merge of #87881 - badboy:platform-support-formatting, r=ehussYuki Okushi-1/+1
Proper table row formatting in platform support Also moves the target into alphabetical order
2021-08-10STD support for the ESP-IDF frameworkivmarkov-0/+1
2021-08-09Proper table row formatting in platform supportJan-Erik Rediger-1/+1
Also moves the target into alphabetical order
2021-08-09Auto merge of #85357 - Andy-Python-Programmer:aarch64_uefi_target, ↵bors-0/+1
r=petrochenkov Add `aarch64-unknown-uefi` target This pull request adds the `aarch64-unknown-uefi` target.
2021-08-09Add the aarch64-unknown-uefi targetunknown-0/+1
* This commit adds the aarch64-unknown-uefi target and also adds it into the supported targets list under the tier-3 target table. * Uses the small code model by default Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
2021-08-04Promote `aarch64-apple-ios-sim` to Tier 2Jan-Erik Rediger-7/+6
As per MCP#428[1] this target becomes Tier 2. [1]: https://github.com/rust-lang/compiler-team/issues/428
2021-08-02Explicit notification of lack of support for `rust-docs` component forAli Malik-0/+4
Tier 2 targets
2021-07-29rfc3052: Remove authors field from Cargo manifestsJade-1/+0
Since RFC 3052 soft deprecated the authors field anyway, hiding it from crates.io, docs.rs, and making Cargo not add it by default, and it is not generally up to date/useful information, we should remove it from crates in this repo.
2021-07-22Add support for powerpc-unknown-freebsdPiotr Kubaj-0/+1
2021-06-17Auto merge of #83572 - pkubaj:patch-1, r=nagisabors-0/+1
Add support for powerpc64le-unknown-freebsd