When the CustomAvailability experimental feature is enabled, make it an error
to specify an unrecognized availability domain name. Also, add these
diagnostics to a diagnostic group so that developers can control their behavior
when they are warnings.
Resolves rdar://152741624.
The migration to `MemberImportVisibility` can be performed mechanically by
adding missing import declarations, so offer automatic migration for the
feature.
Resolves rdar://151931597.
The warnings that ClangImporter emits about issues it encounters while
importing declarations from Clang modules should all belong to a diagnostic
group so that users of `-warnings-as-errors` can control their behavior using
the compiler flags introduce with SE-0443. It's especially important that these
diagnostics be controllable since they are often caused by external
dependencies and therefore the developer may not have any control over whether
they are emitted.
The `#ClangDeclarationImport` diagnostic group is intentionally broad so that
developers have a way to control all of these diagnostics with a single
`-Wwarning` flag. I fully expect that we'll introduce finer-grained diagnostic
groups for some of these diagnostics in the future, but those groups should be
hierarchically nested under `#ClangDeclarationImport`, which is supported by
SE-0443.
Resolves rdar://150524204.
While here, fix some issues around implied isolated conformances (we
could get into an inconsistent state). Also provide an educational
note discussing isolated conformances and the kinds of errors one can
see when they are used from outside of their isolation domain.
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.
Parsing for `-enable-upcoming-feature` and `-enable-experimental-feature` is
lenient by default because some projects need to be compatible with multiple
language versions and compiler toolchains simultaneously, and strict
diagnostics would be a nuisance. On the other hand, though, it would be useful
to get feedback from the compiler when you attempt to enable a feature that
doesn't exist. This change splits the difference by introducing new diagnostics
for potential feature enablement misconfigurations but leaves those diagnostics
ignored by default. Projects that wish to use them can specify `-Wwarning
StrictLanguageFeatures`.
As an example, use this for the "`@preconcurrency` on import has no
effect" warning, which is not yet working correctly. This disables it
by default but leaves it in place for our testing.
This group has not shipped yet and was added mainly to support test
coverage for d56b7df8a9. Now that we have
unit tests for this, delete the group, pending discussion.
This change addresses the following issue: when an error is being wrapped in a warning, the diagnostic message will use the wrapper's `DiagGroupID` as the warning's name. However, we want to retain the original error's group for use. For example, in Swift 5, async_unavailable_decl is wrapped in error_in_future_swift_version. When we print a diagnostic of this kind, we want to keep the `DiagGroupID` of `async_unavailable_decl`, not that of `error_in_future_swift_version`.
To achieve this, we add `DiagGroupID` to the `Diagnostic` class. When an active diagnostic is wrapped in DiagnosticEngine, we retain the original `DiagGroupID`.
For illustration purposes, this change also introduces a new group: `DeclarationUnavailableFromAsynchronousContext`.
With this change, we produce errors and warnings of this kind with messages like the following:
```
global function 'fNoAsync' is unavailable from asynchronous contexts [DeclarationUnavailableFromAsynchronousContext]
global function 'fNoAsync' is unavailable from asynchronous contexts; this is an error in the Swift 6 language mode [DeclarationUnavailableFromAsynchronousContext]
```
This commit adds new compiler options -no-warning-as-error/-warning-as-error which allows users to specify behavior for exact warnings and warning groups.
