Rather than trying to continue the compilation
with an empty main module, let's bail out early if
we expect an implicit stdlib import and fail to
load in the stdlib.
The reasons for disabling it appear to now be
outdated. Re-enable it, and run it after the
entire pipeline has finished to make sure we
verify any decls deserialised during SIL/IRGen.
And also rename the underlying request and
descriptor.
This rename is motivated by the fact that the
operation may instead perform parsing of SIL files
and/or deserialization of SIB files.
This default formatting style remains the same "LLVM style". "Swift style"
is what was previously enabled via -enable-experimental-diagnostic-formatting
There's no longer a technical reason to do this, but it helps
with crash analytics because AST crashes are less likely to
end up happening during index emission.
Rather than eagerly parsing an input .sil file
in `performSemaUpTo`, trigger it from
`performSILGeneration`. This will allow us to
remove the SILModule stored on the
CompilerInstance and will eventually allow the
various SIL tools to just call into
`performSILGeneration` without needing to call
`performSema`.
As part of eliminating cascading dependencies, we need to make sure to
capture any dependencies discovered during SILGen and IRGen.
This is a little bit tricky because we exit early in various places in
the pipeline, so we want to do it after performCompileStepsPostSema()
returns, but we can't do it too late, because the ASTContext might
already have been deallocated.
So emit the dependencies manually before freeing the ASTContext if we
decide to do that, or just do it before returning from performCompile()
using a SWIFT_DEFER otherwise.
This should have no observable effect until we start recording dependencies
for lookups done on behalf of declarations in secondary files.
Add a mode bit to the dependency collector that respects the frontend flag in the previous commit.
Notably, we now write over the dependency files at the end of the compiler pipeline when this flag is on so that dependency from SILGen and IRGen are properly written to disk.
MSVC does not realize that the switch is exhaustive and requires that
the path is explicitly marked as unreachable. This silences the C4715
warning ("not all control paths return a value").
Implement a new "fast" dependency scanning option,
`-scan-dependencies`, in the Swift frontend that determines all
of the source file and module dependencies for a given set of
Swift sources. It covers four forms of modules:
1) Swift (serialized) module files, by reading the module header
2) Swift interface files, by parsing the source code to find imports
3) Swift source modules, by parsing the source code to find imports
4) Clang modules, using Clang's fast dependency scanning tool
A single `-scan-dependencies` operation maps out the full
dependency graph for the given Swift source files, including all
of the Swift and Clang modules that may need to be built, such
that all of the work can be scheduled up front by the Swift
driver or any other build system that understands this
option. The dependency graph is emitted as JSON, which can be
consumed by these other tools.
Inline the conditions for the astGuaranteedToCorrespondToSIL parameter and clean up the logic here to be more const-friendly. Also try to centralize and document the reasons we skip TBD validation.
