Update `proc_macro_derive` to use the attribute template #1888

ehuss · 2025-06-30T23:30:30Z

New rules:

❗ macro.proc.derive.syntax
❗ macro.proc.derive.allowed-positions
❗ macro.proc.derive.duplicates

Renamed rules:

macro.proc.derive.def is now macro.proc.derive.allowed-positions

This renames it to follow the attribute template. Although I like the old title, since it describes what it does, I would prefer to not make exceptions and stay consistent.

This is to follow the attribute template.

One thing worth highlighting is that we're preferring to say that we "declare" (rather than "define") derive macro helper attributes. A definition is something that says what something is. For these attributes, though, we're just declaring that they exist. In revising, we've clarified that the derive macro function must appear in the root of the crate and that it may be `const` and may use `extern` (with the allowed ABI) but may not use other qualifiers. We've also changed the syntax to use `IDENTIFIER` rather than `SimplePathSegment`. In testing, none of the other things that would be accepted by the latter are allowed, so it seems more correct in terms of user-visible behavior to use `IDENTIFIER` here.

Update books ## rust-lang/book 5 commits in b2d1a0821e12a676b496d61891b8e3d374a8e832..3e9dc46aa563ca0c53ec826c41b05f10c5915925 2025-08-02 01:33:29 UTC to 2025-07-14 21:23:38 UTC - Appendix B and Appendix D from tech review (rust-lang/book#4466) - Chapter 21 from tech review (rust-lang/book#4464) - Chapter 20 from tech review (rust-lang/book#4460) - Chapter 19 from tech review (rust-lang/book#4446) - Chapter 18 from tech review (rust-lang/book#4445) ## rust-lang/reference 12 commits in 1f45bd41fa6c17b7c048ed6bfe5f168c4311206a..1be151c051a082b542548c62cafbcb055fa8944f 2025-08-05 19:51:40 UTC to 2025-07-14 19:49:01 UTC - Fix build output directory in README (rust-lang/reference#1950) - Update `link_name` to use the attribute template (rust-lang/reference#1896) - Update `no_link` to use the attribute template (rust-lang/reference#1898) - Update `proc_macro_derive` to use the attribute template (rust-lang/reference#1888) - Update `automatically_derived` to use the attribute template (rust-lang/reference#1884) - Update `derive` to use the attribute template (rust-lang/reference#1883) - Fix and clarify CR LF normalization and CR in string literals (rust-lang/reference#1944) - glossary.md: tweak description of "dispatch" (rust-lang/reference#1938) - add missing id, r[asm.operand-type.supported-operands.const] (rust-lang/reference#1939) - &str and &[u8] have the same layout (rust-lang/reference#1848) - Rename and rewrite the "question mark operator" (rust-lang/reference#1931) - Change "allocated object" to "allocation". (rust-lang/reference#1930) ## rust-lang/rust-by-example 3 commits in e386be5f44af711854207c11fdd61bb576270b04..bd1279cdc9865bfff605e741fb76a0b2f07314a7 2025-08-04 13:41:04 UTC to 2025-08-02 15:41:59 UTC - Improve the activity instructions in `print_display` (rust-lang/rust-by-example#1948) - Minor fixes (whitespace, typo, i32->u32) (rust-lang/rust-by-example#1947) - Document drawbacks of alternatives to match binding (rust-lang/rust-by-example#1946)

Rollup merge of #145026 - rustbot:docs-update, r=ehuss Update books ## rust-lang/book 5 commits in b2d1a0821e12a676b496d61891b8e3d374a8e832..3e9dc46aa563ca0c53ec826c41b05f10c5915925 2025-08-02 01:33:29 UTC to 2025-07-14 21:23:38 UTC - Appendix B and Appendix D from tech review (rust-lang/book#4466) - Chapter 21 from tech review (rust-lang/book#4464) - Chapter 20 from tech review (rust-lang/book#4460) - Chapter 19 from tech review (rust-lang/book#4446) - Chapter 18 from tech review (rust-lang/book#4445) ## rust-lang/reference 12 commits in 1f45bd41fa6c17b7c048ed6bfe5f168c4311206a..1be151c051a082b542548c62cafbcb055fa8944f 2025-08-05 19:51:40 UTC to 2025-07-14 19:49:01 UTC - Fix build output directory in README (rust-lang/reference#1950) - Update `link_name` to use the attribute template (rust-lang/reference#1896) - Update `no_link` to use the attribute template (rust-lang/reference#1898) - Update `proc_macro_derive` to use the attribute template (rust-lang/reference#1888) - Update `automatically_derived` to use the attribute template (rust-lang/reference#1884) - Update `derive` to use the attribute template (rust-lang/reference#1883) - Fix and clarify CR LF normalization and CR in string literals (rust-lang/reference#1944) - glossary.md: tweak description of "dispatch" (rust-lang/reference#1938) - add missing id, r[asm.operand-type.supported-operands.const] (rust-lang/reference#1939) - &str and &[u8] have the same layout (rust-lang/reference#1848) - Rename and rewrite the "question mark operator" (rust-lang/reference#1931) - Change "allocated object" to "allocation". (rust-lang/reference#1930) ## rust-lang/rust-by-example 3 commits in e386be5f44af711854207c11fdd61bb576270b04..bd1279cdc9865bfff605e741fb76a0b2f07314a7 2025-08-04 13:41:04 UTC to 2025-08-02 15:41:59 UTC - Improve the activity instructions in `print_display` (rust-lang/rust-by-example#1948) - Minor fixes (whitespace, typo, i32->u32) (rust-lang/rust-by-example#1947) - Document drawbacks of alternatives to match binding (rust-lang/rust-by-example#1946)

Update books ## rust-lang/book 5 commits in b2d1a0821e12a676b496d61891b8e3d374a8e832..3e9dc46aa563ca0c53ec826c41b05f10c5915925 2025-08-02 01:33:29 UTC to 2025-07-14 21:23:38 UTC - Appendix B and Appendix D from tech review (rust-lang/book#4466) - Chapter 21 from tech review (rust-lang/book#4464) - Chapter 20 from tech review (rust-lang/book#4460) - Chapter 19 from tech review (rust-lang/book#4446) - Chapter 18 from tech review (rust-lang/book#4445) ## rust-lang/reference 12 commits in 1f45bd41fa6c17b7c048ed6bfe5f168c4311206a..1be151c051a082b542548c62cafbcb055fa8944f 2025-08-05 19:51:40 UTC to 2025-07-14 19:49:01 UTC - Fix build output directory in README (rust-lang/reference#1950) - Update `link_name` to use the attribute template (rust-lang/reference#1896) - Update `no_link` to use the attribute template (rust-lang/reference#1898) - Update `proc_macro_derive` to use the attribute template (rust-lang/reference#1888) - Update `automatically_derived` to use the attribute template (rust-lang/reference#1884) - Update `derive` to use the attribute template (rust-lang/reference#1883) - Fix and clarify CR LF normalization and CR in string literals (rust-lang/reference#1944) - glossary.md: tweak description of "dispatch" (rust-lang/reference#1938) - add missing id, r[asm.operand-type.supported-operands.const] (rust-lang/reference#1939) - &str and &[u8] have the same layout (rust-lang/reference#1848) - Rename and rewrite the "question mark operator" (rust-lang/reference#1931) - Change "allocated object" to "allocation". (rust-lang/reference#1930) ## rust-lang/rust-by-example 3 commits in e386be5f44af711854207c11fdd61bb576270b04..bd1279cdc9865bfff605e741fb76a0b2f07314a7 2025-08-04 13:41:04 UTC to 2025-08-02 15:41:59 UTC - Improve the activity instructions in `print_display` (rust-lang/rust-by-example#1948) - Minor fixes (whitespace, typo, i32->u32) (rust-lang/rust-by-example#1947) - Document drawbacks of alternatives to match binding (rust-lang/rust-by-example#1946)

rustbot added the S-waiting-on-review Status: The marked PR is awaiting review from a maintainer label Jun 30, 2025

ehuss added 6 commits August 2, 2025 23:39

Unwrap proc_macro_derive

57cff8c

Rename "Derive macros" section header

63cc743

This renames it to follow the attribute template. Although I like the old title, since it describes what it does, I would prefer to not make exceptions and stay consistent.

Reword proc_macro_derive intro

0163ef7

This is to follow the attribute template.

Move examples into example blocks

eb579f6

Add proc_macro_derive attribute template rules

b70c647

Move proc_macro_attribute rules below the templated rules

1124ff3

traviscross force-pushed the proc_macro_derive branch 4 times, most recently from 0818af1 to 46db920 Compare August 3, 2025 06:53

traviscross force-pushed the proc_macro_derive branch from 46db920 to 89789f6 Compare August 3, 2025 06:57

traviscross approved these changes Aug 3, 2025

View reviewed changes

traviscross added this pull request to the merge queue Aug 3, 2025

Merged via the queue into rust-lang:master with commit dfaaa77 Aug 3, 2025
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rustbot removed the S-waiting-on-review Status: The marked PR is awaiting review from a maintainer label Aug 3, 2025

rustbot mentioned this pull request Aug 6, 2025

Update books rust-lang/rust#145026

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Update `proc_macro_derive` to use the attribute template #1888

Update `proc_macro_derive` to use the attribute template #1888

ehuss commented Jun 30, 2025

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Update proc_macro_derive to use the attribute template #1888

Update proc_macro_derive to use the attribute template #1888

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ehuss commented Jun 30, 2025

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Update `proc_macro_derive` to use the attribute template #1888

Update `proc_macro_derive` to use the attribute template #1888