This avoids having to bring in all members (and extensions!) for an
outer type just to look up a nested type. In the test case attached
(reduced from the project in SR-5284), this actually led to a circular
dependency between deserialization and the importer, which resulted in
a compiler crash.
This is not a new problem, but it's more important with the release of
Swift 4, where a number of Apple SDK types are now newly imported as
member types. (The one in the original bug was
NSView.AutoresizingMask, formerly NSAutoresizingMaskOptions.) Since we
always use the Swift 4 name for cross-references, this affected
everyone, even those still compiling in Swift 3 mode.
https://bugs.swift.org/browse/SR-5284
Special DeclNames represent names that do not have an identifier in the
surface language. This implies serializing the information about whether
a name is special together with its identifier (if it is not special)
in both the module file and the swift lookup table.
Clang's equivalent of this is mapping fatal errors to non-fatal errors.
This isn't something we really care about for users since it's so rare,
but we do use it in our tests, like this one that's been disabled for
a long time.
rdar://problem/30287833
Ever since we stopped associating the top-level struct of an imported
NS_ERROR_ENUM with the Clang enum declaration, we've been unable to
print imported NS_ERROR_ENUMs. The module-printing infrastructure
would drop them thinking they aren't imported declarations.
This also affected NS_ERROR_ENUMs that were imported as members of
another type, as well as other types imported as members.
Fixes rdar://problem/32497693.
Avoids a bogus "argument unused" warning, since bitcode compilation
doesn't bother to set up much of a Clang AST context. (-embed-bitcode
compiles in two steps: source -> bitcode, then bitcode -> object
file. This is about the second step.)
Patch by Bob Wilson, who's currently on vacation but wanted this to
get in sooner rather than later.
rdar://problem/31372950
With the introduction of special decl names, `Identifier getName()` on
`ValueDecl` will be removed and pushed down to nominal declarations
whose name is guaranteed not to be special. Prepare for this by calling
to `DeclBaseName getBaseName()` instead where appropriate.
This changes `getBaseName()` on `DeclName` to return a `DeclBaseName`
instead of an `Identifier`. All places that will continue to be
expecting an `Identifier` are changed to call `getBaseIdentifier` which
will later assert that the `DeclName` is actually backed by an
identifier and not a special name.
For transitional purposes, a conversion operator from `DeclBaseName` to
`Identifier` has been added that will be removed again once migration
to DeclBaseName has been completed in other parts of the compiler.
Unify approach to printing declaration names
Printing a declaration's name using `<<` and `getBaseName()` is be
independent of the return type of `getBaseName()` which will change in
the future from `Identifier` to `DeclBaseName`
getModuleHash in clang now takes a diagnostic engine to get more
information for uniquing the hash - this change was only needed
for swift-4.0-branch, so we're making the API adjustment here.
rdar://problem/32145037
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.
This means all cross-module references and all mangled names will
consistently use the Swift 4 name (the canonical type), no special
handling required.
The main thing we lose here is that the Swift 4 names of imported
types become usable in Swift 3 mode without any diagnostics, similar
to how most language features introduced in Swift 4 are available in
Swift 3 mode. It also implies that the Swift 4 name will show up in
demangled names.
rdar://problem/31616162
- Add CompilerInvocation::getPCHHash
This will be used when creating a unique filename for a persistent
precompiled bridging header.
- Automatically generate and use a precompiled briding header
When we're given both -import-objc-header and -pch-output-dir
arguments, we will try to:
- Validate what we think the PCH filename should be for the bridging
header, based on the Swift PCH hash and the clang module hash.
- If we're successful, we'll just use it.
- If it's out of date or something else is wrong, we'll try to
emit it.
- This gives us a single filename which we can `stat` to check for the
validity of our code completion cache, which is keyed off of module
name, module filename, and module file age.
- Cache code completion results from imported modules
If we just have a single .PCH file imported, we can use that file as
part of the key used to cache declarations in a module. Because
multiple files can contribute to the __ObjC module, we've always given
it the phony filename "<imports>", which never exists, so `stat`-ing it
always fails and we never cache declarations in it.
This is extremely problematic for projects with huge bridging headers.
In the case where we have a single PCH import, this can bring warm code
completion times down to about 500ms from over 2-3s, so it can provide a
nice performance win for IDEs.
- Add a new test that performs two code-completion requests with a bridging header.
- Add some -pch-output-dir flags to existing SourceKit tests that import a bridging
header.
rdar://problem/31198982
