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| author | Nicholas Nethercote <n.nethercote@gmail.com> | 2022-03-29 13:27:59 +1100 |
|---|---|---|
| committer | Nicholas Nethercote <n.nethercote@gmail.com> | 2022-03-30 10:42:47 +1100 |
| commit | ac3d8ce1c6c5a40dfe1203e9873ace219a6e20cf (patch) | |
| tree | 013bc8c4ffef0303208f5197d3926b05c9924d2c | |
| parent | 2b60cc081b31c48a5d9037ba559b6be32974a14f (diff) | |
| download | rust-ac3d8ce1c6c5a40dfe1203e9873ace219a6e20cf.tar.gz rust-ac3d8ce1c6c5a40dfe1203e9873ace219a6e20cf.zip | |
Clarify comments about doc comments in macros.
| -rw-r--r-- | compiler/rustc_expand/src/mbe/macro_parser.rs | 7 | ||||
| -rw-r--r-- | src/test/ui/macros/issue-95267.rs | 5 |
2 files changed, 9 insertions, 3 deletions
diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs index 9d134e398cc..c65b96d4365 100644 --- a/compiler/rustc_expand/src/mbe/macro_parser.rs +++ b/compiler/rustc_expand/src/mbe/macro_parser.rs @@ -517,7 +517,12 @@ impl<'tt> TtParser<'tt> { TokenTree::Token(t) => { // If it's a doc comment, we just ignore it and move on to the next tt in - // the matcher. If the token matches, we can just advance the parser. + // the matcher. This is a bug, but #95267 showed that existing programs + // rely on this behaviour, and changing it would require some care and a + // transition period. + // + // If the token matches, we can just advance the parser. + // // Otherwise, this match has failed, there is nothing to do, and hopefully // another item in `cur_items` will match. if matches!(t, Token { kind: DocComment(..), .. }) { diff --git a/src/test/ui/macros/issue-95267.rs b/src/test/ui/macros/issue-95267.rs index 4d59c7ea5e9..a2fe402bccf 100644 --- a/src/test/ui/macros/issue-95267.rs +++ b/src/test/ui/macros/issue-95267.rs @@ -1,7 +1,8 @@ // check-pass -// This is a valid macro. Commit 4 in #95159 broke things such that it failed -// with a "missing tokens in macro arguments" error, as reported in #95267. +// The doc comment here is ignored. This is a bug, but #95267 showed that +// existing programs rely on this behaviour, and changing it would require some +// care and a transition period. macro_rules! f { ( /// ab |