bors 71569e4201 Auto merge of #75138 - jumbatm:session-diagnostic-derive, r=oli-obk ... Add derive macro for specifying diagnostics using attributes. Introduces `#[derive(SessionDiagnostic)]`, a derive macro for specifying structs that can be converted to Diagnostics using directions given by attributes on the struct and its fields. Currently, the following attributes have been implemented: - `#[code = "..."]` -- this sets the Diagnostic's error code, and must be provided on the struct iself (ie, not on a field). Equivalent to calling `code`. - `#[message = "..."]` -- this sets the Diagnostic's primary error message. - `#[label = "..."]` -- this must be applied to fields of type `Span`, and is equivalent to `span_label` - `#[suggestion(..)]` -- this allows a suggestion message to be supplied. This attribute must be applied to a field of type `Span` or `(Span, Applicability)`, and is equivalent to calling `span_suggestion`. Valid arguments are: - `message = "..."` -- this sets the suggestion message. - (Optional) `code = "..."` -- this suggests code for the suggestion. Defaults to empty. `suggestion`also comes with other variants: `#[suggestion_short(..)]`, `#[suggestion_hidden(..)]` and `#[suggestion_verbose(..)]` which all take the same keys. Within the strings passed to each attribute, fields can be referenced without needing to be passed explicitly into the format string -- eg, `#[error = "{ident} already declared"] ` will set the error message to `format!("{} already declared", &self.ident)`. Any fields on the struct can be referenced in this way. Additionally, for any of these attributes, Option fields can be used to only optionally apply the decoration -- for example: ```rust #[derive(SessionDiagnostic)] #[code = "E0123"] struct SomeKindOfError { ... #[suggestion(message = "informative error message")] opt_sugg: Option<(Span, Applicability)> ... } ``` will not emit a suggestion if `opt_sugg` is `None`. We plan on iterating on this macro further; this PR is a start. Closes #61132. r? `@oli-obk`		2020-09-08 00:58:43 +00:00
..
src	Auto merge of #75138 - jumbatm:session-diagnostic-derive, r=oli-obk	2020-09-08 00:58:43 +00:00
Cargo.toml	mv compiler to compiler/	2020-08-30 18:45:07 +03:00