This patch introduces new diagnostics to the ClangImporter to help
explain why certain C, Objective-C or C++ declarations fail to import
into Swift. This patch includes new diagnostics for the following entities:
- C functions
- C struct fields
- Macros
- Objective-C properties
- Objective-C methods
In particular, notes are attached to indicate when any of the above
entities fail to import as a result of refering an incomplete (only
forward declared) type.
The new diangostics are hidden behind two new flags, -enable-experimental-clang-importer-diagnostics
and -enable-experimental-eager-clang-module-diagnostics. The first flag emits diagnostics lazily,
while the second eagerly imports all declarations visible from loaded Clang modules. The first
flag is intended for day to day swiftc use, the second for module linting or debugging the importer.
When looking for a Swift module on disk, we were scanning all module search paths if they contain the module we are searching for. In a setup where each module is contained in its own framework search path, this scaled quadratically with the number of modules being imported. E.g. a setup with 100 modules being imported form 100 module search paths could cause on the order of 10,000 checks of `FileSystem::exists`. While these checks are fairly fast (~10µs), they add up to ~100ms.
To improve this, perform a first scan of all module search paths and list the files they contain. From this, create a lookup map that maps filenames to the search paths they can be found in. E.g. for
```
searchPath1/
Module1.framework
searchPath2/
Module1.framework
Module2.swiftmodule
```
we create the following lookup table
```
Module1.framework -> [searchPath1, searchPath2]
Module2.swiftmodule -> [searchPath2]
```
We need to modify the pointer pointing to the cancellation flag when reusing an ASTContext for code completion. This is not possible by the previous design because `TypeCheckerOptions` was `const`. Moving the cancellation flag to `ASTContext` will also allow other stages of the compiler to honor a cancellation request.
We noticed some Swift clients rely on the serialized search paths in the module to
find dependencies and droping these paths altogether can lead to build failures like
rdar://85840921.
This change teaches the serialization to obfuscate the search paths and the deserialization
to recover them. This allows clients to keep accessing these paths without exposing
them when shipping the module to other users.
We've recently added the -experimental-hermetic-seal-at-link compiler flag,
which turns on aggressive dead-stripping optimizations and assumes that library
code can be optimized against client code because all users of the library
code/types are present at link/LTO time. This means that any module that's
built with -experimental-hermetic-seal-at-link requires all clients of this
module to also use -experimental-hermetic-seal-at-link. This PR enforces that
by storing a bit in the serialized module, and checking the bit when importing
modules.
c763ab5d1e fixed an issue in
`getSerializedLocs` where it never actually cached its result (and thus
always allocated a new `CachedExternalSourceLocs`). Unfortunately it
missed a leak that could occur when `DocRanges` grows beyond its initial
size of 4.
Allocate `DocRanges` upfront in the `ASTContext` as well in order to
prevent this leak.
Resolves rdar://85472403.
This cleans up 90 instances of this warning and reduces the build spew
when building on Linux. This helps identify actual issues when
building which can get lost in the stream of warning messages. It also
helps restore the ability to build the compiler with gcc.
These modules are part of the experimental declarative string processing feature. If accepted to the Standard Library, _StringProcessing will be available via implicit import just like _Concurrency, though _MatchingEngine will still be hidden as an implementation detail.
`_MatchingEngine` will contain the general-purpose pattern matching engine ISA, bytecode, and executor. `_StringProcessing` will contain regular expression and pattern matching APIs whose implementation depends on the matching engine..
Also consolidates frontend flag `-enable-experimental-regex` as `-enable-experimental-string-processing`.
Resolves rdar://85478647.
The key thing is that the move checker will not consider the explicit copy value
to be a copy_value that can be rewritten, ensuring that any uses of the result
of the explicit copy_value (consuming or other wise) are not checked.
Similar to the _move operator I recently introduced, this is a transparent
function so we can perform one level of specialization and thus at least be
generic over all concrete types.
These include _move and @_noImplicitCopy. I still need to wire up the parsing of
those behind this feature.
The reason that I am adding this now is that I am going to now need to make some
changes behind a feature flag and I have not yet needed to add one. The specific
reason I needed to add one here is to ensure that I properly guard inside _move
the call to Builtin.move so as to prevent a "cond_fail" incident.
P.S.: This work depends on experimental lexical lifetimes being enabled as well,
so I did that at the same time in this PR.
