Adoption so far shows that the criteria we set up here are too broad.
This is particularly problematic for subclasses of NS/UIView and the
like that might never be encoded at all.
rdar://problem/32306355
It can now:
- not validate (=none)
- validate that all symbols in the IR are also in the TBD (=missing),
- validate the above, and also that all in the TBD are in the IR (=all).
The first and last were switched between with the old boolean flag, the
second is new.
Extend the static diagnostics for exclusivity violations to suggest replacing
swap(&collection[index1], &collection[index2]
with
collection.swapAt(index1, index2).
when 'collection' is a MutableCollection.
To do so, repurpose some vestigial code that was previously used to suppress all
exclusivity diagnostics for calls to swap() and add some additional syntactic,
semantic, and textual pattern matching.
rdar://problem/31916085
This is a bit more robust and user-friendly than hoping more brittle recovery in SILGen or IRGen for unsupported components kicks in. rdar://problem/32200714
For the multiple-files mode -emit-pch is still invoked in separate frontend invocation but with using a persistent PCH.
Subsequent frontend invocations use the persistent PCH but they don't need to validate it.
For all-files mode (e.g. WMO) the frontend invocation uses a persistent PCH that it also validates.
Currently -Xcc options are serialized in Swift modules, but they are
not saved as attributes to the DW_TAG_module representing the imported
clang module. This patch saves all *user-specified* -D macros there,
but it does not save any macros that are added by the ClangImporter
itself.
<rdar://problem/31990102>
Some APIs that expected a String now expect a Substring and vice
versa. To ease the transition, emit fix-its on conversion errors
between these types that the migrator can pick up.
When converting from Substring -> String, suggest wrapping in
`String.init`.
When converting from String -> Substring, suggest appending the
void subscript `[]`. (This isn't implemented yet so this is
hidden behind a flag).
This can possibly be generalized later when converting between
some sequence and its subsequence, such as Array and ArraySlice,
for example.
rdar://problem/31665649
rdar://problem/31666638
The warnings about deprecated @objc inference in Swift 3 mode can be a
bit annoying; and are mostly relevant to the migration workflow. Make
the warning emission a three-state switch:
* None (the default): don't warn about these issues.
* Minimal (-warn-swift3-objc-inference-minimal): warn about direct
uses of @objc entrypoints and provide "@objc" Fix-Its for them.
* Complete (-warn-swift3-objc-inference-complete): warn about all
cases where Swift 3 infers @objc but Swift 4 will not.
Fixes rdar://problem/31922278.
Based on recommendations in SE-0160, there are two migration workflows:
- Conservative: Maintain @objc visibility that was inferred in Swift 3
by adding @objc to all declarations that were implicitily visible to
the Objective-C runtime. This is invoked in the migrator by adding the
-migrate-keep-objc-visibility flag.
- Minimal: Only declarations that must be visible to Objective-C based
on their uses (or in cases like dynamic vars) are migrated.
rdar://problem/31876357
I had set up the driver to invoke a separate frontend invocation with
the "update code" mode. We sort of did this last release, except we
forked to the swift-update binary instead. This is causing problems with
testing in Xcode.
Instead, let's perform a single compile and add the remap file as an
additional output during normal compiles. The driver, seeing
-update-code, will add -emit-remap-file-path $PATH to the -c frontend
invocation.
rdar://problem/31857580
These data files are installed into runtime resource directory so that migrator can pick them automatically according to specific platforms. To support testing, a front-end option -api-diff-data-file can be used to specify the data file to use and it will overwrite the default ones from resource directory.
The Swift 4 Migrator is invoked through either the driver and frontend
with the -update-code flag.
The basic pipeline in the frontend is:
- Perform some list of syntactic fixes (there are currently none).
- Perform N rounds of sema fix-its on the primary input file, currently
set to 7 based on prior migrator seasons. Right now, this is just set
to take any fix-it suggested by the compiler.
- Emit a replacement map file, a JSON file describing replacements to a
file that Xcode knows how to understand.
Currently, the Migrator maintains a history of migration states along
the way for debugging purposes.
- Add -emit-remap frontend option
This will indicate the EmitRemap frontend action.
- Don't fork to a separte swift-update binary.
This is going to be a mode of the compiler, invoked by the same flags.
- Add -disable-migrator-fixits option
Useful for debugging, this skips the phase in the Migrator that
automatically applies fix-its suggested by the compiler.
- Add -emit-migrated-file-path option
This is used for testing/debugging scenarios. This takes the final
migration state's output text and writes it to the file specified
by this option.
- Add -dump-migration-states-dir
This dumps all of the migration states encountered during a migration
run for a file to the given directory. For example, the compiler
fix-it migration pass dumps the input file, the output file, and the
remap file between the two.
State output has the following naming convention:
${Index}-${MigrationPassName}-${What}.${extension}, such as:
1-FixitMigrationState-Input.swift
rdar://problem/30926261
