Implement built-in attribute macro #[cfg_eval] + some refactoring
#82682
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r? @varkor (rust-highfive has picked a reviewer for you, use r? to override) |
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…acros` This logic is applicable to two specific macros and not to the expansion infrastructure in general.
This is simpler and mirrors what invocation collector does
#[cfg_eval]#[cfg_eval] + some refactoring
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This should be ready for review.
r? @Aaron1011 |
Aaron1011
reviewed
Mar 7, 2021
| @@ -1452,6 +1452,18 @@ pub(crate) mod builtin { | |||
| /* compiler built-in */ | |||
| } | |||
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| /// Expands all `#[cfg]` and `#[cfg_attr]` attributes in the code fragment it's applied to. | |||
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We should add an example here prior to stabilization, but it doesn't need to block this PR.
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@bors r+ |
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📌 Commit 5d27728 has been approved by |
Dylan-DPC-zz
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Implement built-in attribute macro `#[cfg_eval]` + some refactoring This PR implements a built-in attribute macro `#[cfg_eval]` as it was suggested in rust-lang#79078 to avoid `#[derive()]` without arguments being abused as a way to configure input for other attributes. The macro is used for eagerly expanding all `#[cfg]` and `#[cfg_attr]` attributes in its input ("fully configuring" the input). The effect is identical to effect of `#[derive(Foo, Bar)]` which also fully configures its input before passing it to macros `Foo` and `Bar`, but unlike `#[derive]` `#[cfg_eval]` can be applied to any syntax nodes supporting macro attributes, not only certain items. `cfg_eval` was the first name suggested in rust-lang#79078, but other alternatives are also possible, e.g. `cfg_expand`. ```rust #[cfg_eval] #[my_attr] // Receives `struct S {}` as input, the field is configured away by `#[cfg_eval]` struct S { #[cfg(FALSE)] field: u8, } ``` Tracking issue: rust-lang#82679
Dylan-DPC-zz
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Mar 8, 2021
Implement built-in attribute macro `#[cfg_eval]` + some refactoring This PR implements a built-in attribute macro `#[cfg_eval]` as it was suggested in rust-lang#79078 to avoid `#[derive()]` without arguments being abused as a way to configure input for other attributes. The macro is used for eagerly expanding all `#[cfg]` and `#[cfg_attr]` attributes in its input ("fully configuring" the input). The effect is identical to effect of `#[derive(Foo, Bar)]` which also fully configures its input before passing it to macros `Foo` and `Bar`, but unlike `#[derive]` `#[cfg_eval]` can be applied to any syntax nodes supporting macro attributes, not only certain items. `cfg_eval` was the first name suggested in rust-lang#79078, but other alternatives are also possible, e.g. `cfg_expand`. ```rust #[cfg_eval] #[my_attr] // Receives `struct S {}` as input, the field is configured away by `#[cfg_eval]` struct S { #[cfg(FALSE)] field: u8, } ``` Tracking issue: rust-lang#82679
Dylan-DPC-zz
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Mar 8, 2021
Implement built-in attribute macro `#[cfg_eval]` + some refactoring This PR implements a built-in attribute macro `#[cfg_eval]` as it was suggested in rust-lang#79078 to avoid `#[derive()]` without arguments being abused as a way to configure input for other attributes. The macro is used for eagerly expanding all `#[cfg]` and `#[cfg_attr]` attributes in its input ("fully configuring" the input). The effect is identical to effect of `#[derive(Foo, Bar)]` which also fully configures its input before passing it to macros `Foo` and `Bar`, but unlike `#[derive]` `#[cfg_eval]` can be applied to any syntax nodes supporting macro attributes, not only certain items. `cfg_eval` was the first name suggested in rust-lang#79078, but other alternatives are also possible, e.g. `cfg_expand`. ```rust #[cfg_eval] #[my_attr] // Receives `struct S {}` as input, the field is configured away by `#[cfg_eval]` struct S { #[cfg(FALSE)] field: u8, } ``` Tracking issue: rust-lang#82679
Dylan-DPC-zz
pushed a commit
to Dylan-DPC-zz/rust
that referenced
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Mar 8, 2021
Implement built-in attribute macro `#[cfg_eval]` + some refactoring This PR implements a built-in attribute macro `#[cfg_eval]` as it was suggested in rust-lang#79078 to avoid `#[derive()]` without arguments being abused as a way to configure input for other attributes. The macro is used for eagerly expanding all `#[cfg]` and `#[cfg_attr]` attributes in its input ("fully configuring" the input). The effect is identical to effect of `#[derive(Foo, Bar)]` which also fully configures its input before passing it to macros `Foo` and `Bar`, but unlike `#[derive]` `#[cfg_eval]` can be applied to any syntax nodes supporting macro attributes, not only certain items. `cfg_eval` was the first name suggested in rust-lang#79078, but other alternatives are also possible, e.g. `cfg_expand`. ```rust #[cfg_eval] #[my_attr] // Receives `struct S {}` as input, the field is configured away by `#[cfg_eval]` struct S { #[cfg(FALSE)] field: u8, } ``` Tracking issue: rust-lang#82679
This was referenced Mar 8, 2021
bors
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Rollup of 10 pull requests Successful merges: - rust-lang#82047 (bypass auto_da_alloc for metadata files) - rust-lang#82415 (expand: Refactor module loading) - rust-lang#82557 (Add natvis for Result, NonNull, CString, CStr, and Cow) - rust-lang#82613 (Remove Item::kind, use tagged enum. Rename variants to match) - rust-lang#82642 (Fix jemalloc usage on OSX) - rust-lang#82682 (Implement built-in attribute macro `#[cfg_eval]` + some refactoring) - rust-lang#82684 (Disable destination propagation on all mir-opt-levels) - rust-lang#82755 (Refactor confirm_builtin_call, remove partial if) - rust-lang#82857 (Edit ructc_ast_lowering docs) - rust-lang#82862 (Generalize Write impl for Vec<u8> to Vec<u8, A>) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
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This PR implements a built-in attribute macro
#[cfg_eval]as it was suggested in #79078 to avoid#[derive()]without arguments being abused as a way to configure input for other attributes.The macro is used for eagerly expanding all
#[cfg]and#[cfg_attr]attributes in its input ("fully configuring" the input).The effect is identical to effect of
#[derive(Foo, Bar)]which also fully configures its input before passing it to macrosFooandBar, but unlike#[derive]#[cfg_eval]can be applied to any syntax nodes supporting macro attributes, not only certain items.cfg_evalwas the first name suggested in #79078, but other alternatives are also possible, e.g.cfg_expand.Tracking issue: #82679