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]
```
The new type, called ExistentialType, is not yet used in type resolution.
Later, existential types written with `any` will resolve to this type, and
bare protocol names will resolve to this type depending on context.
Adding the ability to add an optional message to the unavailable from
async attribute. This can be used to indicate other possible API to use,
or help explain why it's unavailable.
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.
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 restrictions are meant to keep placeholder types from escaping TypeCheckType. But there's really no harm in that happening as long as we diagnose it on the way out in the places it's banned. (We also need to make sure we're only diagnosing things in primaries, but that's a minor issue). The end result is that we lose information because a lot of the AST that has placeholders in it becomes filled with error types instead.
Lift the restriction on placeholders appearing in the interface type, teach the mangler to treat them as unresolved types, and teach serialization to treat them as error types.
Stage in the parsing for this attribute, nothing else.
Motivated by two important reasons:
1) The pitch for variadic generics does not lay down a concrete syntax
for variadic generic parameters.
2) Paring T... and T* needlessly complicate the lexer as we must now
disambiguate them with respect to other internal operator characters
(e.g. `T...>` must lex as `(T...)>` and not `T ...>`
Which itself adds another motivation
3) We need to start parsing this attribute *now* to avoid condfail'ing
ourselves later.
This attribute creates an unavailable extension with a `Sendable` conformance so that the type is explicity marked as not being `Sendable`.
We also fully suppress diagnostics about unavailable Sendable conformances in Swift 5 mode code. (This is not fully developed yet—it should return to being a warning in concurrent contexts.)
The behavior when a @_nonSendable and a Sendable conformance are both on the same type is also not right yet.
This commit adds a new frontend flag that applies debug path prefixing to the
paths serialized in swiftmodule files. This makes it possible to use swiftmodule
files that have been built on different machines by applying the inverse map
when debugging, in a similar fashion to source path prefixing.
The inverse mapping in LLDB will be handled in a follow up PR.
Second pass at #39138
Tests updated to handle windows path separators.
This reverts commit f5aa95b381.
* Fix unnecessary one-time recompile of stdlib with -enable-ossa-flag
This includes a bit in the module format to represent if the module was
compiled with -enable-ossa-modules flag. When compiling a client module
with -enable-ossa-modules flag, all dependent modules are checked for this bit,
if not on, recompilation is triggered with -enable-ossa-modules.
* Updated tests
This commit adds the `-prefix-serialized-debugging-options` flag,
which is used to apply the debug prefix map to serialized debugging
options embedded in the swiftmodule files.
Serialization was reporting that it did not have fingerprints for these declarations. When combined with the driver's new type body fingerprint work for extensions, this effectively hid changes to the bodies of these nested types from the driver's incremental build infrastructure.
Make sure we recur into all of the iterable decl contexts when serializing decls to collect as many fingerprints as we can.
rdar://83469936
Introduce a new loading restriction that is more strict than the serialization
version check on swiftmodules. Tagged compilers will only load
library-evolution enabled swiftmodules that are produced by a compiler with the
exact same revision id. This will be more reliable in production
environments than using the serialization version which we forgot to
update from time to time. This shouldn't affect development compilers that
will still load any module with a compatible serialization version.
rdar://83105234
Serialize the canonical name of the SDK used when building a swiftmodule
file and use it to ensure that the swiftmodule file is loaded only with
the same SDK. The SDK name must be passed down from the frontend.
This will report unsupported configurations like:
- Installing roots between incompatible SDKs without deleting the
swiftmodule files.
- Having multiple targets in the same project using different SDKs.
- Loading a swiftmodule created with a newer SDK (and stdlib) with an
older SDK.
All of these lead to hard to investigate deserialization failures and
this change should detect them early, before reaching a deserialization
failure.
rdar://78048939
