{"action":"created","issue":{"url":"https://api.github.com/repos/rust-lang/rust/issues/3065","labels_url":"https://api.github.com/repos/rust-lang/rust/issues/3065/labels{/name}","comments_url":"https://api.github.com/repos/rust-lang/rust/issues/3065/comments","events_url":"https://api.github.com/repos/rust-lang/rust/issues/3065/events","html_url":"https://github.com/rust-lang/rust/issues/3065","id":5956120,"number":3065,"title":"Syntax backtraces don't work for the new macro system","user":{"login":"paulstansifer","id":1431,"avatar_url":"https://avatars.githubusercontent.com/u/1431?v=3","gravatar_id":"","url":"https://api.github.com/users/paulstansifer","html_url":"https://github.com/paulstansifer","followers_url":"https://api.github.com/users/paulstansifer/followers","following_url":"https://api.github.com/users/paulstansifer/following{/other_user}","gists_url":"https://api.github.com/users/paulstansifer/gists{/gist_id}","starred_url":"https://api.github.com/users/paulstansifer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/paulstansifer/subscriptions","organizations_url":"https://api.github.com/users/paulstansifer/orgs","repos_url":"https://api.github.com/users/paulstansifer/repos","events_url":"https://api.github.com/users/paulstansifer/events{/privacy}","received_events_url":"https://api.github.com/users/paulstansifer/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/rust-lang/rust/labels/A-macros","name":"A-macros","color":"d7e102"},{"url":"https://api.github.com/repos/rust-lang/rust/labels/A-syntaxext","name":"A-syntaxext","color":"d7e102"},{"url":"https://api.github.com/repos/rust-lang/rust/labels/E-easy","name":"E-easy","color":"02e10c"},{"url":"https://api.github.com/repos/rust-lang/rust/labels/P-low","name":"P-low","color":"eb6420"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":10,"created_at":"2012-07-31T23:14:02Z","updated_at":"2015-10-03T14:55:04Z","closed_at":null,"body":"`log_syntax!` should emit, in this case, information about the invocation of my_complex_macro(), but doesn't. I believe that this can be fixed by having transcribe.rs set up `expn_info` the way that simplext.rs does.\n\n````\nmacro_rules! my_complex_macro {\n    { } => { log_syntax!(\"asdf\"); }\n}\n\nfn main() {\n    io::println(my_complex_macro!());\n}\n````"},"comment":{"url":"https://api.github.com/repos/rust-lang/rust/issues/comments/145254517","html_url":"https://github.com/rust-lang/rust/issues/3065#issuecomment-145254517","issue_url":"https://api.github.com/repos/rust-lang/rust/issues/3065","id":145254517,"user":{"login":"carols10cents","id":193874,"avatar_url":"https://avatars.githubusercontent.com/u/193874?v=3","gravatar_id":"","url":"https://api.github.com/users/carols10cents","html_url":"https://github.com/carols10cents","followers_url":"https://api.github.com/users/carols10cents/followers","following_url":"https://api.github.com/users/carols10cents/following{/other_user}","gists_url":"https://api.github.com/users/carols10cents/gists{/gist_id}","starred_url":"https://api.github.com/users/carols10cents/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/carols10cents/subscriptions","organizations_url":"https://api.github.com/users/carols10cents/orgs","repos_url":"https://api.github.com/users/carols10cents/repos","events_url":"https://api.github.com/users/carols10cents/events{/privacy}","received_events_url":"https://api.github.com/users/carols10cents/received_events","type":"User","site_admin":false},"created_at":"2015-10-03T14:55:04Z","updated_at":"2015-10-03T14:55:04Z","body":"(Hi, I'm trying to [help make E-easy issues more accessible to newcomers](https://users.rust-lang.org/t/mentoring-newcomers-to-the-rust-ecosystem/3088/15?u=carols10cents) :smile_cat:)\r\n\r\n[I tried reproducing this](http://is.gd/VyySAV) and it compiles and prints \"asdf\". From [the book chapter on macros](https://doc.rust-lang.org/stable/book/macros.html#debugging-macro-code):\r\n\r\n> `log_syntax!(...)` will print its arguments to standard output, at compile time, and \"expand\" to nothing.\r\n\r\nThis sounds like `log_syntax!` is behaving as expected? Unless \"its arguments\" is referring to *the macro's arguments* as opposed to *`log_syntax!`'s arguments*...?\r\n\r\nI'm also not sure how to interpret [paulstansifer's comment](https://github.com/rust-lang/rust/issues/3065#issuecomment-17304443):\r\n\r\n> It should give a \"backtrace\" of errors, indicating both of the invocations that led to the error.\r\n\r\nWhat error is this referring to? Which two invocations is this referring to?\r\n\r\nBasically... is this still an issue? If so, it's sounding more like an additional feature to `log_syntax!`, not a bug...?"}}