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.
As part of this, we have to change the type export rules to
prevent `@convention(c)` function types from being used in
exported interfaces if they aren't serializable. This is a
more conservative version of the original rule I had, which
was to import such function-pointer types as opaque pointers.
That rule would've completely prevented importing function-pointer
types defined in bridging headers and so simply doesn't work,
so we're left trying to catch the unsupportable cases
retroactively. This has the unfortunate consequence that we
can't necessarily serialize the internal state of the compiler,
but that was already true due to normal type uses of aggregate
types from bridging headers; if we can teach the compiler to
reliably serialize such types, we should be able to use the
same mechanisms for function types.
This PR doesn't flip the switch to use Clang function types
by default, so many of the clang-function-type-serialization
FIXMEs are still in place.
This reverts commit e805fe486e, which reverted
the change earlier. The problem was caused due to a simultaneous change to some
code by the PR with parsing and printing for Clang function types (#28737)
and the PR which introduced Located<T> (#28643).
This commit also includes a small change to make sure the intersecting region
is fixed: the change is limited to using the fields of Located<T> in the
`tryParseClangType` lambda.
This is primarily meant to used for testing LLDB's DWARFImporterDelegate,
however, this could become the default option for LLDB once
DWARFImporterDelegate is sufficiently mature.
<rdar://problem/57880844>
Note: The change in ASTBuilder::createFunctionType is functionally minor,
but we need the FunctionType::Params computed _before_ the ExtInfo, so we
need to shuffle a bunch of code around.
- No need to hash input values first
- Pass many values to a single hash_combine to save on intermediates
- Use hash_combine_range instead of a loop of hash_combines
No functionality change.
While most -Xcc options turn into options that affect the Clang module
cache hash, some, like search paths, do not, and that can have a
drastic effect on PCH contents. When combined with places where Xcode
will modify invocations to add extra -Xcc options (see
rdar://problem/23297285), this can lead to crashes where the
modified-invocation PCH is used to compile source files in incremental
mode, and then the original, non-precompiled bridging header is used
for module merging. Let's just be conservative and include -Xcc
options in the Swift-side PCH uniqueness hash.
rdar://problem/33837253
Most of AST, Parse, and Sema deal with FileUnits regularly, but SIL
and IRGen certainly don't. Split FileUnit out into its own header to
cut down on recompilation times when something changes.
No functionality change.
Removes duplicated logic from the implementations of
FileUnit::lookupValue, and simplifies the interface to
ModuleDecl::lookupValue, where everyone was passing an empty
(non-filtering) access path anyway /except/ during actual lookup from
source code. No functionality change.
We already do this for other ASTContext-allocated types (see
Decl.cpp). This will prevent the sort of mistakes in the previous two
commits.
Note that if any particular subclass of FileUnit wants to have its
destructor run, it can opt into that manually using
ASTContext::addDestructorCleanup. SourceFile and BuiltinUnit both do
this. But we generally don't /want/ to do this if we can avoid it
because it adds to compiler teardown time.
For reproducers in LLDB, we need to collect module dependency
information coming from the clang importer. However, we cannot override
the dependency collector, like we do in LLDB, because its interface is
completely hidden in the clang importer. The solution is to pass the
FileCollector through the DependencyTracker.
(cherry picked from commit c624a87bd5)
The clang importer has to deal with two virtual file systems, one coming
from clang, and one coming from swift. Currently, if both are set, we
emit a diagnostic that we'll pick the swift one.
This commit changes that, by merging the two virtual file systems. The
motivation for this change is the reproducer infrastructure in LLDB,
which adds a third virtual file system to the mix.
(cherry picked from commit 94ef5431ff)
The only place this was used in Decl.h was the failability kind of a
constructor.
I decided to replace this with a boolean isFailable() bit. Now that
we have isImplicitlyUnwrappedOptional(), it seems to make more sense
to not have ConstructorDecl represent redundant information which
might not be internally consistent.
Most callers of getFailability() actually only care if the result is
failable or not; the few callers that care about it being IUO can
check isImplicitlyUnwrappedOptional() as well.
