The diagnostics formatter from swift-syntax previously only handled
fully-formed diagnostics anchored at a particular syntax node.
Therefore, the compiler would fall back to the existing LLVM-based
diagnostic formatter for diagnostics that had no source location.
Adopt new API in the swift-syntax diagnostics formatter that renders a
diagnostic message without requiring source location information, so
that we consistently use the swift-syntax formatter when it is
selected (which is the default).
We've been converging the implementations of educational notes and
diagnostic groups, where both provide category information in
diagnostics (e.g., `[#StrictMemorySafety]`) and corresponding
short-form documentation files. The diagnostic group model is more
useful in a few ways:
* It provides warnings-as-errors control for warnings in the group
* It is easier to associate a diagnostic with a group with
GROUPED_ERROR/GROUPED_WARNING than it is to have a separate diagnostic
ID -> mapping.
* It is easier to see our progress on diagnostic-group coverage
* It provides an easy name to use for diagnostic purposes.
Collapse the educational-notes infrastructure into diagnostic groups,
migrating all of the existing educational notes into new groups.
Simplify the code paths that dealt with multiple educational notes to
have a single, possibly-missing "category documentation URL", which is
how we're treating this.
When printing diagnostics, category names are printed as [#<category-name>]
at the end of a diagnostic. For all of the category names that are mentioned
in this manner, print "footnotes" at the end of compilation providing
documentation references to each category, e.g.,
[#deprecated]: <http://example.com/deprecated>
[#StrictMemorySafety]: <http://example.com/memory-safety>
Right now, these point into the markdown files in the installed toolchain,
same as the URLs behind references. That is subject to change in the future.
`DiagnosticEngine` has an API that allows to attach notes to a "primary"
diagnostic (an error or a warning). This works well with old formatting
(`llvm`) but `swift` formatter doesn't display attached notes which makes
some diagnostics very hard to work with i.e. `invalid_redecl`.
Bridge the category name and educational note computed for the Swift
compiler's diagnostics to the newly-introduced category field for
the swift-syntax diagnostics. This lets the swift-syntax renderer
introduce the category name and (optionally) link to the
documentation.
* Make ExportedSourceFile hold any Syntax as the root node
* Move `ExportedSourceFileRequest::evaluate()` to `ParseRequests.cpp`
* Pass the decl context and `GeneatedSourceFileInfo::Kind` to
`swift_ASTGen_parseSourceFile()` to customize the parsing
* Make `ExportedSourceFile` to hold an arbitrary Syntax node
* Move round-trip checking into `ExportedSourceFileRequest::evaluate()`
* Split `parseSourceFileViaASTGen` completely from C++ parsing logic
(in `ParseSourceFileRequest::evaluate()`)
* Remove 'ParserDiagnostics' experimental feature: Now that we have
ParserASTGen mode which includes the swift-syntax parser diagnostics.
