Skip to content
Open
Show file tree
Hide file tree
Changes from 10 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
42 changes: 42 additions & 0 deletions GOALS.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,42 @@
# Goals

## Elevator pitch

We will make Rust coding guidelines are available within this repository, deployed to an accessible location on the internet which comply with relevant standards for various safety-critical industries such as: IEC 61508, ISO 26262, and DO 178.
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Something about this sentence is missing, I believe.

Was it intended to go like:

We will make sure Rust coding guidelines are available within this repository, (...)

or perhaps something along the lines of...

We will make Rust coding guidelines. Such guidelines are available within this repository, (...)

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, one of those two, thanks for catching the phrasing

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Okay, cleaned this up into three sentences instead so it's a bit easier to comprehend.


## Detailed

In general these coding guidelines will be a set of rules of do / do not do with examples which should cover all "general" aspects of the Rust programming language, e.g. enums, structs, traits, and so on. We will use the [FLS](https://rust-lang.github.io/fls/index.html) as a means to ensure we have reasonable coverage of the language.

There will be an addendum which covers how various safety standards like ISO 26262 map onto the coding guidelines.

## Criteria

* We produce coding guidelines that make a "best effort" attempt at cataloging common pieces (e.g. functions, arithmetic, unsafe) of the Rust programming language and how they fit into a safety-critical project
* We will use [MISRA Compliance: 2020](https://misra.org.uk/app/uploads/2021/06/MISRA-Compliance-2020.pdf) for categorization
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Which part of the MISRA Compliance: 2020 document are we using? (the pdf is 39 pages long)

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

scary voice: the whole thing!!

But seriously, @AlexCeleste may be better equipped to tell us if we need cite a page range or the entire document.

* We include a rationale with links to parts of the Rust Project and wider Rust community for guidance
* We will include linkage where appropriate to to various standards, e.g. CERT C, MISRA C, DO 178, ISO 26262
* We will include practical recommendations on how to use this piece of the language using compliant and non-compliant examples
* We will develop an addendum matrix to reduce burden of attaching these later
* We will begin with DO 178 and ISO 26262 at perhaps chapter level, maybe subsection level _for now_ and expand later
* We will release the coding guidelines tagged with the versions of stable Rust that they support (e.g. `1.42`)
* We will create Clippy lints which will cover decidable guidelines

### Criteria obtained by discussion with Tooling Subcommittee

* We will affix a label for each guideline, which describes whether said guideline is decidable or not (in the theory of computation sense)
* We will include for each guideline a minimum of one compliant and one non-compliant example of code, to help illustrate its exact meaning and context.
* We will consider only the language reference / spec, not the tooling availability when writing the coding guidelines
* We aim to produce evidence-based guidelines, with statistics around human error when programming Rust, to support:
1. What guidelines are written, and
2. Why a specific suggestion was made
* We will produce the guidelines in an artifact that's easily machine readable and consistent format to make it easier to consume by tool vendors as a baseline (e.g. multiple JSON files, one per language piece, also potentially one large JSON concatenated together)
Copy link
Collaborator

@felix91gr felix91gr Sep 18, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What do you mean here by "as a baseline"? :o

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ah, okay. I guess the phrasing here may not be clear. The idea is that we will satisfy the Tooling Subcommittee's ask by providing these JSON files. If they need more they can come back and we can discuss.

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'll take another pass to clarify

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Clarified what exactly we're producing today


# Explicit non-goals

* For the initial version to be complete coverage of the Rust programming language
* "Something" shipped to alleviate pressure at organizations is better than "nothing is available" even if we have to heavily subset the language
* For any version to be conflict-free with various members' or their organizations' viewpoints
* Members and their organizations may take different stances on how Rust programming language constructs should be viewed and approached. This is **okay and expected**.
* We'd like to ship something that we can obtain broad consensus on.
* Worst case scenario: there may be a section here or there which you may need to adjust in an internal version that'd downstream.
95 changes: 82 additions & 13 deletions README.md
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,9 @@

Coding Guidelines for Safety Critical Rust developed by the [Safety Critical Rust Consortium][safety-critical-rust-consortium].

[View the latest rendered guidelines online](https://rustfoundation.github.io/safety-critical-rust-coding-guidelines/)
[View the latest rendered guidelines online](https://coding-guidelines.arewesafetycriticalyet.org/)

Check out the [coding guideline goals](GOALS.md).

_Note_: Early, subject to changes.

Expand Down Expand Up @@ -42,7 +44,7 @@ A machine-parseable artifact will be available at `build/html/needs.json`. (ToDo
A record with checksums of the contents is available at `build/html/guidelines-ids.json`. Users of the coding guidelines can reference this file to determine if there have been changes to coding guidelines contents they should be aware of.


## Running builds offline
### Running builds offline

If you're working without internet access or want to avoid reaching out to remote resources, you can pass the `--offline` flag:

Expand All @@ -55,7 +57,7 @@ This prevents the build system from attempting to fetch remote resources, such a
It is recommended to use `--offline` if you are running `make.py` frequently during development. The builder fetches data from [the Ferrocene Language Specification website](https://spec.ferrocene.dev/paragraph-ids.json), which may rate-limit repeated requests—leading to delays or failed builds. Using `--offline` can significantly improve build speed and avoid unnecessary network issues during iterative work.


## Build breaking due to out-dated spec lock file
### Build breaking due to out-dated spec lock file

It's a fairly common occurrence for the build to break due to an out of date spec lock file, located at:

Expand Down Expand Up @@ -101,34 +103,101 @@ Once you have completed the above steps, you will now update the local copy of t

Open a new PR with only the changes necessary to rationalize the guidelines with the new FLS text.

## Outline & issue breakdown

We will use the Coding Guidelines Work Items [board](https://github.com/orgs/rustfoundation/projects/1) as a means to break the work down into smaller chunks that can be tackled in a reasonable manner.

## Contributing to the coding guidelines

See [CONTRIBUTING.md](CONTRIBUTING.md).
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I wonder if this entire section should go inside of CONTRIBUTING.md instead?

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It is getting long, isn't it? I could see the argument

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Okay, extracted this out


### Chapter layout mirrors Ferrocene Language Specification
### Diagram for contribution workflow

We have the same chapter layout as the [Ferrocene Language Specification](https://spec.ferrocene.dev/) (FLS). If you would like to contribute you may find a section from the FLS of interest and then write a guideline in the corresponding chapter of these coding guidelines.
```mermaid
flowchart TD
Start(["Start"]) --> Idea["Coding Guideline Idea"]
Idea --> Zulip[/"(Optional)<br>0: Contributor brings <br> to discuss on Zulip"/]
Zulip --> CreateIssue{{"1: Contributor creates <br> issue"}}
CreateIssue --> Issue["Coding Guideline Issue"]

### Guideline template
%% short local loops (no long edges)
S2{{"2: Review started <br> by subcommittee <br> member in <= 14 days <br><br> Contributor updates accordingly"}} --> Issue
Issue --> S2

We have a script `./generate_guideline_templates.py` which assumes you're using `uv` that can be run to generate the template for a guideline with properly randomized IDs.
Issue --> S3{{"3: Subcommitte member <br> assigns label<br>to generate PR"}} --> PR["Coding Guideline<br>Pull Request"]

You can the copy and paste this guideline from the command line into the correct chapter.
S4{{"4: PR review started <br> by subcommittee member <br> in <= 14 days <br><br> Contributor discusses on PR"}} --> PR
PR --> S4

### Filling out the guideline
PR --> S5{{"5: Contributor applies <br> feedback to issue"}} --> Issue
Issue --> S6{{"6: Subcommittee member <br> confirms changes;<br> regenerates PR"}} --> PR
PR --> S7{{"7: Subcommittee member <br> approves & queues;<br>merges to main"}} --> Main[[main]]
Main --> End(["8: End"])
```

Reference `src/conf.py` to see valid selections for unfilled options in the guideline template.
### 0. Have an idea for a coding guideline? Want to discuss it?

Note that the `:fls:` option should be filled according to the FLS paragraph ID for which the guideline is covering. One way to go about finding this is to inspect the page using your web browser. You'll be looking for something like:
While not mandatory, sometimes you'd like to check into the feasiblity of a guideline or discuss it with others to ensure it's not overlapping an existing guideline. Feel free to drop by the Safety-Critical Rust Consortium's Zulip stream: [here](https://rust-lang.zulipchat.com/#narrow/channel/445688-safety-critical-consortium). Please open a new topic per coding guideline you'd like to discuss.

### Preamble: chapter layout mirrors Ferrocene Language Specification

We have the same chapter layout as the [Ferrocene Language Specification](https://spec.ferrocene.dev/) (FLS). If you would like to contribute you may find a section from the FLS of interest and then write a guideline in the corresponding chapter of these coding guidelines.

### 1. Submit coding guideline issue

For a new coding guideline you'd like to contribute, start with opening a [coding guideline issue](https://github.com/rustfoundation/safety-critical-rust-coding-guidelines/issues/new?template=CODING-GUIDELINE.yml).

#### 1.a Finding the FLS ID

Note that the FLS ID should be filled according to the FLS paragraph ID for which the guideline is covering. One way to go about finding this is to inspect the page using your web browser. You'll be looking for something like:

```html
<p><span class="spec-paragraph-id" id="fls_4rhjpdu4zfqj">4.1:1</span>
```

You would then pull `fls_4rhjpdu4zfqj` to place in the `:fls:` option.
You would then pull `fls_4rhjpdu4zfqj` to place in the FLS ID field.

### 2. A subcommittee member reviews the coding guideline issue, works with you the contributor

A member of the Coding Guidelines Subcommittee should get you a first review with some feedback within 14 days of submission. You'll work with one or more members to flesh out the concept and ensure the guideline is well prepared.

### 3. A pull request is generated from the coding guideline issue

Once an issue has been well-developed enough, a subcommittee member will mark the issue with the label `sign-off: create pr from issue` to generate a pull request. You will see a GitHub Workflow trigger and a pull request will be created momentarily.

Existing guidelines can also serve as examples on how guidelines are filled.
### 4. Contributor responds to feedback given on pull request

The generated pull request may attract additional feedback or simply be an easier place to suggest targeted edits.

As the contributor of the coding guideline and opener of the issue, you'll respond to comments, discuss, all the normal things on the pull request.

### 5. Contributor applies updates to coding guidelines issue

If you agree with the suggested changes, rather than making changes on the opened pull request, you will return to the original issue you opened via the coding guideline issue template and make the updates there.

### 6. A subcommittee member generates new pull request contents from coding guidelines issue

When you have completed all feedback given to you, ping one of the subcommittee members. They will then remove and affix the label `sign-off: create pr from issue` to push the changes made in the issue to the already opened pull request.

### 7. A subcommittee member merges the coding guideline pull request

Once the coding guideline contents have passed review, a subcommittee member will approve the pull request, and put it on the merge queue to be merged.

### 8. You contributed a coding guideline

That's it!

## Writing a guideline locally (less typical, not recommended)

While it is possible to create guidelines locally and open pull requests yourself, we encourage contributors to make use of the process described above since it handled some of the fiddly details for you as a guideline writer.

Generally speaking, pull requests for guidelines which do not follow the issue to pull request workflow described above will be closed with a recommendation to follow the workflow.

### Guideline template

We have a script `./generate_guideline_templates.py` which assumes you're using `uv` that can be run to generate the template for a guideline with properly randomized IDs.

You can the copy and paste this guideline from the command line into the correct chapter.

## [Code of Conduct][code-of-conduct]

Expand Down