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kmcallister opened this issue Feb 16, 2015 · 2 comments · Fixed by #30011
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"macro expansion ignores" error should explain why #22425

kmcallister opened this issue Feb 16, 2015 · 2 comments · Fixed by #30011
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A-diagnostics Area: Messages for errors, warnings, and lints A-macros Area: All kinds of macros (custom derive, macro_rules!, proc macros, ..) E-easy Call for participation: Easy difficulty. Experience needed to fix: Not much. Good first issue.

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@kmcallister
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afaik, it's because the context where you're using the macro (expr, item, etc.) stopped parsing before that token. We should mention that context.
@kmcallister kmcallister added E-easy Call for participation: Easy difficulty. Experience needed to fix: Not much. Good first issue. A-diagnostics Area: Messages for errors, warnings, and lints A-macros Area: All kinds of macros (custom derive, macro_rules!, proc macros, ..) labels Feb 16, 2015
@kmcallister kmcallister self-assigned this Feb 16, 2015
@kmcallister kmcallister removed their assignment Mar 3, 2015
@whipsch whipsch mentioned this issue Apr 4, 2015
Merged
bors added a commit that referenced this issue Apr 7, 2015
@bors
Auto merge of #24078 - whipsch:extra-token-msg, r=huonw
aecd165 
Addresses issue #22425.  See `src/test/compile-fail/macro-incomplete-parse.rs` for a relevant test:

    macro-incomplete-parse.rs:15:9: 15:10 error: macro expansion ignores token `,` and any following
    macro-incomplete-parse.rs:15         , //~ ERROR macro expansion ignores token `,`
                                         ^
    macro-incomplete-parse.rs:27:1: 27:17 note: caused by the macro expansion here; the usage of `ignored_item` is likely invalid in this context
    macro-incomplete-parse.rs:27 ignored_item!();
                                 ^~~~~~~~~~~~~~~~
    macro-incomplete-parse.rs:20:14: 20:15 error: macro expansion ignores token `,` and any following
    macro-incomplete-parse.rs:20     () => ( 1, 2 ) //~ ERROR macro expansion ignores token `,`
                                              ^
    macro-incomplete-parse.rs:30:5: 30:21 note: caused by the macro expansion here; the usage of `ignored_expr` is likely invalid in this context
    macro-incomplete-parse.rs:30     ignored_expr!();
                                     ^~~~~~~~~~~~~~~~
    macro-incomplete-parse.rs:24:14: 24:15 error: macro expansion ignores token `,` and any following
    macro-incomplete-parse.rs:24     () => ( 1, 2 ) //~ ERROR macro expansion ignores token `,`
                                              ^
    macro-incomplete-parse.rs:32:9: 32:23 note: caused by the macro expansion here; the usage of `ignored_pat` is likely invalid in this context
    macro-incomplete-parse.rs:32         ignored_pat!() => (),
                                         ^~~~~~~~~~~~~~

This does not address the case of improper expansion inside of an impl { } as seen in issue #21607.


I'm not sure if the note text is ideal, but it can be refined if needed.
bors added a commit that referenced this issue Apr 8, 2015
@bors
Auto merge of #24078 - whipsch:extra-token-msg, r=huonw
ce97c19 
Addresses issue #22425.  See `src/test/compile-fail/macro-incomplete-parse.rs` for a relevant test:

    macro-incomplete-parse.rs:15:9: 15:10 error: macro expansion ignores token `,` and any following
    macro-incomplete-parse.rs:15         , //~ ERROR macro expansion ignores token `,`
                                         ^
    macro-incomplete-parse.rs:27:1: 27:17 note: caused by the macro expansion here; the usage of `ignored_item` is likely invalid in this context
    macro-incomplete-parse.rs:27 ignored_item!();
                                 ^~~~~~~~~~~~~~~~
    macro-incomplete-parse.rs:20:14: 20:15 error: macro expansion ignores token `,` and any following
    macro-incomplete-parse.rs:20     () => ( 1, 2 ) //~ ERROR macro expansion ignores token `,`
                                              ^
    macro-incomplete-parse.rs:30:5: 30:21 note: caused by the macro expansion here; the usage of `ignored_expr` is likely invalid in this context
    macro-incomplete-parse.rs:30     ignored_expr!();
                                     ^~~~~~~~~~~~~~~~
    macro-incomplete-parse.rs:24:14: 24:15 error: macro expansion ignores token `,` and any following
    macro-incomplete-parse.rs:24     () => ( 1, 2 ) //~ ERROR macro expansion ignores token `,`
                                              ^
    macro-incomplete-parse.rs:32:9: 32:23 note: caused by the macro expansion here; the usage of `ignored_pat` is likely invalid in this context
    macro-incomplete-parse.rs:32         ignored_pat!() => (),
                                         ^~~~~~~~~~~~~~

This does not address the case of improper expansion inside of an impl { } as seen in issue #21607.


I'm not sure if the note text is ideal, but it can be refined if needed.
@wesleywiser
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Is this fixed? I think this was fixed the referenced pull request.

@jonas-schievink
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I'd prefer a message like the use of X is likely invalid in this {statement, expression, pattern, ...} context

@jonas-schievink jonas-schievink mentioned this issue Nov 23, 2015
Merged
bors added a commit that referenced this issue Nov 25, 2015
@bors
Auto merge of #30011 - jonas-schievink:macro-context, r=nrc
7fa2c6c 
Fixes #22425

Also fixes #30007, since it's just a change from `true` to `false`.
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A-diagnostics Area: Messages for errors, warnings, and lints A-macros Area: All kinds of macros (custom derive, macro_rules!, proc macros, ..) E-easy Call for participation: Easy difficulty. Experience needed to fix: Not much. Good first issue.
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Print the macro context name on incomplete parse
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@kmcallister @wesleywiser @jonas-schievink