Document inert vs active attributes #1110

Aaron1011 · 2021-04-16T21:55:57Z

This PR adds a subsection to the 'Syntax and AST' section describing
inert vs active attributes.

For consistency, I've also updated the '#[test] implementation' page to
stop referring to `#[test]' as a 'built in' attribute, since that has a
specific meaning defined on this page.

This PR adds a subsection to the 'Syntax and AST' section describing inert vs active attributes. For consistency, I've also updated the '#[test] implementation' page to stop referring to `#[test]' as a 'built in' attribute, since that has a specific meaning defined on this page.

camelid

This looks really good, thanks for writing it up! I left a few typographical nits. I can't comment much on the content because I'm learning about attributes by reading this PR ;)

camelid · 2021-04-16T22:00:17Z

src/attributes.md

+  As a result, any behavior comes as a result of the compiler explicitly checking for their presence
+  (for example, lint-related code explicitly checks for `#[allow]`, `#[warn]`, `#[deny]`, and
+`#[forbid]`)


Might be nice to add a bit more to make it clear what the distinction is:

Suggested change

As a result, any behavior comes as a result of the compiler explicitly checking for their presence

(for example, lint-related code explicitly checks for `#[allow]`, `#[warn]`, `#[deny]`, and

`#[forbid]`)

As a result, any behavior comes as a result of the compiler explicitly checking for their presence.

For example, lint-related code explicitly checks for `#[allow]`, `#[warn]`, `#[deny]`, and

`#[forbid]`, rather than the behavior coming from the expansion of the attributes themselves.

camelid · 2021-04-16T22:05:47Z

src/attributes.md

+2. Ast-based attributes, defined in the standard library. These attributes have special 'stub'
+   macros defined in places like [`library/core/src/macros/mod.rs`][core_macros]


Suggested change

2. Ast-based attributes, defined in the standard library. These attributes have special 'stub'

macros defined in places like [`library/core/src/macros/mod.rs`][core_macros]

2. AST-based attributes, defined in the standard library. These attributes have special 'stub'

macros defined in places like [`library/core/src/macros/mod.rs`][core_macros].

camelid · 2021-04-16T22:06:32Z

src/attributes.md

+These definitions exist to allow the macros to participate in typical path-based resolution - they
+can be imported, re-exported, and renamed just like any other item definition. However, the body of
+the definition is empty. Instead, the macro is annotated with the `#[rustc_builtin_macro]`
+attribute, which tells the compiler to run a corresponding function in `rustc_builtin_macros`.


Could you add a link to the crate's API docs? That way it is easy for people to see more about it, and it will make our CI fail if the name ever changes.

camelid · 2021-04-16T22:08:42Z

src/attributes.md

@@ -0,0 +1,49 @@
+# Attributes
+
+Attributes come in two types - 'builtin'/'inert' attributes, and 'non-builtin'/'active' attributes:


I feel like the single quotes here and in the headings make the text a bit harder to read; are you okay with removing them?

They are 'inert', meaning they are left as-is by the macro expansion code.

This one seems fine to keep, but I feel that the others make it harder to read.

camelid · 2021-04-16T22:09:06Z

src/attributes.md

+These attributes are defined in the compiler itself, in
+[`compiler/rustc_feature/src/builtin_attrs.rs`][builtin_attrs]
+
+Example include `#[allow]` and `#[macro_use]`


Suggested change

These attributes are defined in the compiler itself, in

[`compiler/rustc_feature/src/builtin_attrs.rs`][builtin_attrs]

Example include `#[allow]` and `#[macro_use]`

These attributes are defined in the compiler itself, in

[`compiler/rustc_feature/src/builtin_attrs.rs`][builtin_attrs].

Examples include `#[allow]` and `#[macro_use]`.

camelid · 2021-04-16T22:09:29Z

src/attributes.md

+These attributes are defined by a crate - either the standard library, or a proc-macro crate.
+**Important**: Many non-builtin attributes, such as `#[derive]`, are still considered part of the


I think this note might be easier to read as a new paragraph:

Suggested change

These attributes are defined by a crate - either the standard library, or a proc-macro crate.

**Important**: Many non-builtin attributes, such as `#[derive]`, are still considered part of the

These attributes are defined by a crate - either the standard library, or a proc-macro crate.

**Important**: Many non-builtin attributes, such as `#[derive]`, are still considered part of the

petrochenkov · 2021-04-17T06:58:22Z

cfg and cfg_attr are probably worth mentioning as third category because they are both built-in (in the sense that they don't go through name resolution) and active (expanded directly by the compiler).

rylev · 2021-07-04T18:20:39Z

@Aaron1011 will you be able to work on this to get it over the finish line? I'd love to see it merged.

pierwill · 2021-12-13T17:26:41Z

src/attributes.md

@@ -0,0 +1,49 @@
+# Attributes
+
+Attributes come in two types - 'builtin'/'inert' attributes, and 'non-builtin'/'active' attributes:


Suggested change

Attributes come in two types - 'builtin'/'inert' attributes, and 'non-builtin'/'active' attributes:

Attributes come in two types: *inert* (or *built-in*) and *active* (*non-builtin*).

Could switch these around as well if we prefer. (*built-in* (or *inert*))

I like italics for the first time a new term is introduced.

pierwill · 2021-12-13T17:27:09Z

src/attributes.md

+
+Attributes come in two types - 'builtin'/'inert' attributes, and 'non-builtin'/'active' attributes:
+
+## 'Builtin'/'inert' attributes


Suggested change

## 'Builtin'/'inert' attributes

## Builtin/inert attributes

pierwill · 2021-12-13T17:29:38Z

src/test-implementation.md

@@ -2,7 +2,7 @@

 <!-- toc -->

-Today, rust programmers rely on a built in attribute called `#[test]`. All
+Today, rust programmers rely on an attribute called `#[test]`. All


Suggested change

Today, rust programmers rely on an attribute called `#[test]`. All

Today, Rust programmers rely on an attribute called `#[test]`. All

JohnTitor · 2022-11-20T04:00:28Z

@Aaron1011 I'm not sure if this is still up-to-date, could you check? It'd also be great if you could address review comments.

spastorino · 2023-02-15T14:26:26Z

I'm not sure what's the current status of this PR, but I guess it may be better to merge it and continue working on it on master.
Opinions?.

spastorino · 2023-10-26T14:20:06Z

I'm not sure what's the current status of this PR, but I guess it may be better to merge it and continue working on it on master. Opinions?.

Any comment about this ☝️ ?

camelid added the waiting-on-review This PR is waiting for a reviewer to verify its content label Apr 16, 2021

camelid reviewed Apr 16, 2021

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camelid added waiting-on-author This PR is waiting for additional action by the OP and removed waiting-on-review This PR is waiting for a reviewer to verify its content labels Apr 19, 2021

pierwill reviewed Dec 13, 2021

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Document inert vs active attributes #1110

Document inert vs active attributes #1110

Aaron1011 commented Apr 16, 2021

camelid left a comment

camelid Apr 16, 2021

camelid Apr 16, 2021

camelid Apr 16, 2021

camelid Apr 16, 2021

camelid Apr 16, 2021

camelid Apr 16, 2021

petrochenkov commented Apr 17, 2021

rylev commented Jul 4, 2021

pierwill Dec 13, 2021

pierwill Dec 13, 2021

pierwill Dec 13, 2021

pierwill Dec 13, 2021

JohnTitor commented Nov 20, 2022

spastorino commented Feb 15, 2023

spastorino commented Oct 26, 2023

		2. Ast-based attributes, defined in the standard library. These attributes have special 'stub'
		macros defined in places like [`library/core/src/macros/mod.rs`][core_macros]

		@@ -0,0 +1,49 @@
		# Attributes

		Attributes come in two types - 'builtin'/'inert' attributes, and 'non-builtin'/'active' attributes:

		These attributes are defined by a crate - either the standard library, or a proc-macro crate.
		Important: Many non-builtin attributes, such as `#[derive]`, are still considered part of the

	Attributes come in two types - 'builtin'/'inert' attributes, and 'non-builtin'/'active' attributes:
	Attributes come in two types: inert (or built-in) and active (non-builtin).


		Attributes come in two types - 'builtin'/'inert' attributes, and 'non-builtin'/'active' attributes:

		## 'Builtin'/'inert' attributes

	Today, rust programmers rely on an attribute called `#[test]`. All
	Today, Rust programmers rely on an attribute called `#[test]`. All

Document inert vs active attributes #1110

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Document inert vs active attributes #1110

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petrochenkov commented Apr 17, 2021

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JohnTitor commented Nov 20, 2022

spastorino commented Feb 15, 2023

spastorino commented Oct 26, 2023