rust/tests/ui/proc-macro/nested-derive-cfg.stdout

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

84 lines
3.4 KiB
Plaintext
Raw Normal View History

2021-02-28 19:51:44 +00:00
PRINT-DERIVE INPUT (DISPLAY): struct Foo
Improve `print_tts` by changing `tokenstream::Spacing`. `tokenstream::Spacing` appears on all `TokenTree::Token` instances, both punct and non-punct. Its current usage: - `Joint` means "can join with the next token *and* that token is a punct". - `Alone` means "cannot join with the next token *or* can join with the next token but that token is not a punct". The fact that `Alone` is used for two different cases is awkward. This commit augments `tokenstream::Spacing` with a new variant `JointHidden`, resulting in: - `Joint` means "can join with the next token *and* that token is a punct". - `JointHidden` means "can join with the next token *and* that token is a not a punct". - `Alone` means "cannot join with the next token". This *drastically* improves the output of `print_tts`. For example, this: ``` stringify!(let a: Vec<u32> = vec![];) ``` currently produces this string: ``` let a : Vec < u32 > = vec! [] ; ``` With this PR, it now produces this string: ``` let a: Vec<u32> = vec![] ; ``` (The space after the `]` is because `TokenTree::Delimited` currently doesn't have spacing information. The subsequent commit fixes this.) The new `print_tts` doesn't replicate original code perfectly. E.g. multiple space characters will be condensed into a single space character. But it's much improved. `print_tts` still produces the old, uglier output for code produced by proc macros. Because we have to translate the generated code from `proc_macro::Spacing` to the more expressive `token::Spacing`, which results in too much `proc_macro::Along` usage and no `proc_macro::JointHidden` usage. So `space_between` still exists and is used by `print_tts` in conjunction with the `Spacing` field. This change will also help with the removal of `Token::Interpolated`. Currently interpolated tokens are pretty-printed nicely via AST pretty printing. `Token::Interpolated` removal will mean they get printed with `print_tts`. Without this change, that would result in much uglier output for code produced by decl macro expansions. With this change, AST pretty printing and `print_tts` produce similar results. The commit also tweaks the comments on `proc_macro::Spacing`. In particular, it refers to "compound tokens" rather than "multi-char operators" because lifetimes aren't operators.
2023-08-08 01:43:44 +00:00
{ my_array: [bool; { struct Inner { non_removed_inner_field: usize } 0 }] }
PRINT-DERIVE DEEP-RE-COLLECTED (DISPLAY): struct Foo
{ my_array : [bool; { struct Inner { non_removed_inner_field : usize } 0 }] }
2021-02-28 19:51:44 +00:00
PRINT-DERIVE INPUT (DEBUG): TokenStream [
Ident {
ident: "struct",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:12:1: 12:7 (#0),
2021-02-28 19:51:44 +00:00
},
Ident {
ident: "Foo",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:12:8: 12:11 (#0),
2021-02-28 19:51:44 +00:00
},
Group {
delimiter: Brace,
stream: TokenStream [
Ident {
ident: "my_array",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:14:5: 14:13 (#0),
2021-02-28 19:51:44 +00:00
},
Punct {
ch: ':',
spacing: Alone,
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:14:13: 14:14 (#0),
2021-02-28 19:51:44 +00:00
},
Group {
delimiter: Bracket,
stream: TokenStream [
Ident {
ident: "bool",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:14:16: 14:20 (#0),
2021-02-28 19:51:44 +00:00
},
Punct {
ch: ';',
spacing: Alone,
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:14:20: 14:21 (#0),
2021-02-28 19:51:44 +00:00
},
Group {
delimiter: Brace,
stream: TokenStream [
Ident {
ident: "struct",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:15:9: 15:15 (#0),
2021-02-28 19:51:44 +00:00
},
Ident {
ident: "Inner",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:15:16: 15:21 (#0),
2021-02-28 19:51:44 +00:00
},
Group {
delimiter: Brace,
stream: TokenStream [
Ident {
ident: "non_removed_inner_field",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:17:13: 17:36 (#0),
2021-02-28 19:51:44 +00:00
},
Punct {
ch: ':',
spacing: Alone,
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:17:36: 17:37 (#0),
2021-02-28 19:51:44 +00:00
},
Ident {
ident: "usize",
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:17:38: 17:43 (#0),
2021-02-28 19:51:44 +00:00
},
],
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:15:22: 18:10 (#0),
2021-02-28 19:51:44 +00:00
},
Literal {
kind: Integer,
symbol: "0",
suffix: None,
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:19:9: 19:10 (#0),
2021-02-28 19:51:44 +00:00
},
],
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:14:22: 20:6 (#0),
2021-02-28 19:51:44 +00:00
},
],
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:14:15: 20:7 (#0),
2021-02-28 19:51:44 +00:00
},
],
Implement token-based handling of attributes during expansion This PR modifies the macro expansion infrastructure to handle attributes in a fully token-based manner. As a result: * Derives macros no longer lose spans when their input is modified by eager cfg-expansion. This is accomplished by performing eager cfg-expansion on the token stream that we pass to the derive proc-macro * Inner attributes now preserve spans in all cases, including when we have multiple inner attributes in a row. This is accomplished through the following changes: * New structs `AttrAnnotatedTokenStream` and `AttrAnnotatedTokenTree` are introduced. These are very similar to a normal `TokenTree`, but they also track the position of attributes and attribute targets within the stream. They are built when we collect tokens during parsing. An `AttrAnnotatedTokenStream` is converted to a regular `TokenStream` when we invoke a macro. * Token capturing and `LazyTokenStream` are modified to work with `AttrAnnotatedTokenStream`. A new `ReplaceRange` type is introduced, which is created during the parsing of a nested AST node to make the 'outer' AST node aware of the attributes and attribute target stored deeper in the token stream. * When we need to perform eager cfg-expansion (either due to `#[derive]` or `#[cfg_eval]`), we tokenize and reparse our target, capturing additional information about the locations of `#[cfg]` and `#[cfg_attr]` attributes at any depth within the target. This is a performance optimization, allowing us to perform less work in the typical case where captured tokens never have eager cfg-expansion run.
2020-11-28 23:33:17 +00:00
span: $DIR/nested-derive-cfg.rs:12:12: 21:2 (#0),
2021-02-28 19:51:44 +00:00
},
]