Handle macros with multiple kinds, and improve errors by joshtriplett · Pull Request #145153 · rust-lang/rust
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Aug 11, 2025jdonszelmann added a commit to jdonszelmann/rust that referenced this pull request
Aug 13, 2025…=petrochenkov Handle macros with multiple kinds, and improve errors (I recommend reviewing this commit-by-commit.) Switch to a bitflags `MacroKinds` to support macros with more than one kind Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`. Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds. This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`. Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes. This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules. Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors. This also handles cases of forward-referenced attributes and cyclic attributes. ---- In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds. rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that. ---- r? `````@petrochenkov`````
bors added a commit that referenced this pull request
Aug 13, 2025Rollup of 9 pull requests Successful merges: - #122661 (Change the desugaring of `assert!` for better error output) - #138736 (Sanitizers target modificators) - #144955 (search graph: lazily update parent goals) - #145120 (llvm: Accept new LLVM lifetime format) - #145153 (Handle macros with multiple kinds, and improve errors) - #145189 (Weekly `cargo update`) - #145250 (Add regression test for former ICE involving malformed meta items containing interpolated tokens) - #145309 (Fix `-Zregparm` for LLVM builtins) - #145331 (Make std use the edition 2024 prelude) r? `@ghost` `@rustbot` modify labels: rollup
GuillaumeGomez added a commit to GuillaumeGomez/rust that referenced this pull request
Aug 13, 2025…=petrochenkov Handle macros with multiple kinds, and improve errors (I recommend reviewing this commit-by-commit.) Switch to a bitflags `MacroKinds` to support macros with more than one kind Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`. Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds. This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`. Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes. This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules. Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors. This also handles cases of forward-referenced attributes and cyclic attributes. ---- In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds. rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that. ---- r? ``````@petrochenkov``````
GuillaumeGomez added a commit to GuillaumeGomez/rust that referenced this pull request
Aug 13, 2025…=petrochenkov Handle macros with multiple kinds, and improve errors (I recommend reviewing this commit-by-commit.) Switch to a bitflags `MacroKinds` to support macros with more than one kind Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`. Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds. This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`. Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes. This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules. Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors. This also handles cases of forward-referenced attributes and cyclic attributes. ---- In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds. rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that. ---- r? ```````@petrochenkov```````
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Aug 13, 2025bors added a commit that referenced this pull request
Aug 13, 2025Rollup of 9 pull requests Successful merges: - #144761 (aarch64: Make `outline-atomics` a known target feature) - #144949 (More `Printer` cleanups) - #144955 (search graph: lazily update parent goals) - #144962 (Add aarch64_be-unknown-none-softfloat target) - #145153 (Handle macros with multiple kinds, and improve errors) - #145241 ([AVR] Changed data_layout) - #145341 (Install libgccjit into the compiler's sysroot when cg_gcc is enabled) - #145349 (Correctly handle when there are no unstable items in the documented crate) - #145356 (Add another example for escaped `#` character in doctest in rustdoc book) r? `@ghost` `@rustbot` modify labels: rollup
rust-timer added a commit that referenced this pull request
Aug 13, 2025Rollup merge of #145153 - joshtriplett:macro-kinds-plural, r=petrochenkov Handle macros with multiple kinds, and improve errors (I recommend reviewing this commit-by-commit.) Switch to a bitflags `MacroKinds` to support macros with more than one kind Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`. Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds. This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`. Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes. This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules. Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors. This also handles cases of forward-referenced attributes and cyclic attributes. ---- In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds. rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that. ---- r? ````````@petrochenkov````````
jhpratt added a commit to jhpratt/rust that referenced this pull request
Aug 16, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
Zalathar added a commit to Zalathar/rust that referenced this pull request
Aug 16, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
Zalathar added a commit to Zalathar/rust that referenced this pull request
Aug 17, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
Zalathar added a commit to Zalathar/rust that referenced this pull request
Aug 17, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
Zalathar added a commit to Zalathar/rust that referenced this pull request
Aug 17, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
Zalathar added a commit to Zalathar/rust that referenced this pull request
Aug 17, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
Zalathar added a commit to Zalathar/rust that referenced this pull request
Aug 17, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
Zalathar added a commit to Zalathar/rust that referenced this pull request
Aug 18, 2025…enkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop rust-lang#145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: rust-lang#143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
rust-timer added a commit that referenced this pull request
Aug 18, 2025Rollup merge of #145208 - joshtriplett:mbe-derive, r=petrochenkov Implement declarative (`macro_rules!`) derive macros (RFC 3698) This is a draft for review, and should not be merged yet. This is layered atop #145153 , and has only two additional commits atop that. The first handles parsing and provides a test for various parse errors. The second implements expansion and handles application. This implements RFC 3698, "Declarative (`macro_rules!`) derive macros". Tracking issue: #143549 This has one remaining issue, which I could use some help debugging: in `tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for `derive(fn_only)` (for a `fn_only` with no `derive` rules) and `derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate diagnostic. From what I can tell via adding some debugging code, `unresolved_macro_suggestions` is getting called twice from `finalize_macro_resolutions` for each of them, because `self.single_segment_macro_resolutions` has two entries for the macro, with two different `parent_scope` values. I'm not clear on why that happened; it doesn't happen with the equivalent code using attrs. I'd welcome any suggestions for fixing this.
flip1995 pushed a commit to flip1995/rust that referenced this pull request
Aug 22, 2025…=petrochenkov Handle macros with multiple kinds, and improve errors (I recommend reviewing this commit-by-commit.) Switch to a bitflags `MacroKinds` to support macros with more than one kind Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`. Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds. This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`. Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes. This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules. Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors. This also handles cases of forward-referenced attributes and cyclic attributes. ---- In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds. rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that. ---- r? ````````@petrochenkov````````
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