An "API descriptor" file is JSON describing the externally accessible symbols
of a module and metadata associated with those symbols like availability and
SPI status. This output was previously only generated by the
`swift-api-extract` alias of `swift-frontend`, which is desgined to take an
already built module as input. Post-processing a built module to extract this
information is inefficient because the module and the module's dependencies
need to be deserialized in order to visit the entire AST. We can generate this
output more efficiently as a supplementary output of the -emit-module job that
originally produced the module (since the AST is already available in-memory).
The -emit-api-descriptor flag can be used to request this output.
This change lays the groundwork by introducing frontend flags. Follow up
changes are needed to make API descriptor emission during -emit-module
functional.
Part of rdar://110916764.
For whatever reason, using standard headers in modules imported from
Swift code (i.e. depending on Darwin overlay) is no longer an issue.
rdar://115438609
Conflict in CAS options when
`std::vector<std::string> CacheReplayPrefixMap;` was added.
Conflicts:
include/swift/Frontend/FrontendOptions.h
Resolution: Take both
In C++20, the compiler will synthesize a version of the operator
with its arguments reversed to ease commutativity. This reversed
version is ambiguous with the hand-written operator when the
argument is const but `this` isn't.
Conflicts:
- `CMakeLists.txt` caused by the extra `-D` added in rebranch to
reduce the number of deprecation warnings.
- `lib/Frontend/PrintingDiagnosticConsumer.cpp` caused by the removal
of one of the `#if SWIFT_SWIFT_PARSER` on rebranch (probably should
have been done on main).
Using `-Rmodule-api-import` the compiler prints a remark about the
import bringing in every decl used in public function signatures or
inlinable code. It also remarks on the source of conformances where they
are used and the source of typealias underlying types.
Teach CachedDiagnosticsProcessor to replay diagnostics for all consumers
with a different path using a path prefix map. This allows diagnostics
to be replayed for the actual path on disk after the scanner
canonicalized the path for compilation.
Allow DependencyScanner to canonicalize path using a prefix map. When
option `-scanner-prefix-map` option is used, dependency scanner will
remap all the input paths in following:
* all the paths in the CAS file system or clang include tree
* all the paths related to input on the command-line returned by scanner
This allows all the input paths to be canonicalized so cache key can be
computed reguardless of the exact on disk path.
The sourceFile field is not remapped so build system can track the exact
file as on the local file system.
An existing test (Frontend/skip-function-bodies.swift) was designed under the
assumption that multiple `-debug-forbid-typecheck-prefix` arguments were
already supported, and as a result the test was not actually asserting what it
was written to assert.
'ModuleDependencyScanner' maintains a Thread Pool along with a pool of workers
which are capable of executing a filesystem lookup of a named module dependency.
When resolving imports of a given Swift module, each import's resolution
operation can be issued asunchronously.
From being a scattered collection of 'static' methods in ScanDependencies.cpp
and member methods of ASTContext. This makes 'ScanDependencies.cpp' much easier
to read, and abstracts the actual scanning logic away to a place with common
state which will make it easier to reason about in the future.
When using `-enable-experimental-feature` on a non-asserts build,
we only emit an error diagnostic that has no source-line information
and continue to enable the feature.
That doesn't actually prevent use of the experimental feature when
you are passing `-typecheck -verify`, since in diagnostics verification
mode, a diagnostic with an unknown error location is ignored. Thus,
the experimental feature is enabled and run for type-checking, but
the compiler would exit with a zero error code.
This patch takes a hammer to that escape-hatch, forcing an early
non-zero exit the moment an experimental feature is requested. The
error message is output to stderr so that CI and other tools should see
what happened.
For chains of async functions where suspensions can be statically
proven to never be required, this pass removes all suspensions and
turns the functions into synchronous functions.
For example, this function does not actually require any suspensions,
once the correct executor is acquired upon initial entry:
```
func fib(_ n: Int) async -> Int {
if n <= 1 { return n }
return await fib(n-1) + fib(n-2)
}
```
So we can turn the above into this for better performance:
```
func fib() async -> Int {
return fib_sync()
}
func fib_sync(_ n: Int) -> Int {
if n <= 1 { return n }
return fib(n-1) + fib(n-2)
}
```
while rewriting callers of `fib` to use the `sync` entry-point
when we can prove that it will be invoked on a compatible executor.
This pass is currently experimental and under development. Thus, it
is disabled by default and you must use
`-enable-experimental-async-demotion` to try it.
