This replaces usages of `llvm::fs` and string manipulation with
`std::filesystem`, also replacing `std::string` with
`std::filesystem::path` where it made sense.
Moreover MD5 hashing used in macOS file remapping was replaced by
SHA256 hashing using a small header-only SHA256 C++ library with an
MIT license, https://github.com/okdshin/PicoSHA2.
File contents hashing was relocated to the newly created `file` library
for later planned reuse.
There were missing extractions from the Builtin (and other) modules.
This was actually caused by two issues:
* we did not visit all required modules, as for example the `Builtin`
module does not appear as being imported by anybody (together with
another mysterious `__Objc` module)
* moreover the `Builtin` module works internally by only creating
declarations on demand, and does not provide a list of its top level
declarations.
The first problem was solved by moving module collection to the actual
visiting. This may mean we extract less modules, as we only extract the
modules we actually use something from (recursively). This change can
be reverted if we feel we need it.
The second one was solved by explicitly listing the builtin symbols
encountered during a normal extraction. This does mean this list needs
to be kept up to date.
This should cover `-merge-modules` mode.
Dumping of the configuration to the target files was moved to a
separate pair of header/source files, as now it is also done in
`SwiftOutputRewrite.cpp`.
Previously we were not extracting any `swiftmodule` file that was not
a system or a built-in one. This was done to avoid re-extracting
`swiftmodule` files that were built previously in the same build, but it
turned out to be too eager, as there are legitimate cases where a
non-system, non-built-in precompiled swift module can be used. An
example of that is the `PackageDescription` module used in Swift
Package Manager manifest files (`Package.swift`).
We now relax the test and trigger module extraction on all loaded
modules that do not have source files (we trigger source file extraction
for those). The catch, is that we also create empty trap files for
current output `swiftmodule` files (including possible alias locations
set up by XCode).
This means that if a following extractor run loads a previously built
`swiftmodule` file, although it will trigger module extraction, this
will however be skipped as it will find its target file already present
(this is done via the `TargetFile` semantics).
Firstly, this change reworks how inter-process races are resolved.
Moreover some responsability reorganization has led to merging
`TrapArena` and `TrapOutput` again into a `TrapDomain` class.
A `TargetFile` class is introduced, that is successfully created
only for the first process that starts processing a given trap output
file. From then on `TargetFile` simply wraps around `<<` stream
operations, dumping them to a temporary file. When `TargetFile::commit`
is called, the temporary file is moved on to the actual target trap
file.
Processes that lose the race can now just ignore the unneeded
extraction and go on, while previously all processes would carry out
all extractions overwriting each other at the end.
Some of the file system logic contained in `SwiftExtractor.cpp` has been
moved to this class, and two TODOs are solved:
* introducing a better inter process file collision avoidance strategy
* better error handling for trap output operations: if unable to write
to the trap file (or carry out other basic file operations), we just
abort.
The changes to `ExprVisitor` and `StmtVisitor` are due to wanting to
hide the raw `TrapDomain::createLabel` from them, and bring more
funcionality under the generic caching/dispatching mechanism.
As `ASTMangler` crashes when called on `ModuleDecl`, we simply use
its name.
This might probably not work reliably in a scenario where multiple
modules are compiled with the same name (like `main`), but this is left
for future work. At the moment this cannot create DB inconsistencies.
Currently, we have a number of assertions in the codebase and certain
assumptions about the AST. These don't always hold, sometimes leading to
a crash in the extractor.
The crashes leave incomplete TRAP files that cannot be imported into the
database.
With this change, we still get those incomplete TRAP files, but we also
get a database in the end (even thoough it is also incomplete as we
cannot import everything).
Visitor code has been split between header and sources to speed up
incremental build. Moreover the code was reorganized using a new `infra`
bazel package (and `visitors` got promoted to a bazel package as well).
This was temporarily broken as we were skipping full emission of all
entities without any valid location.
We now rely on `decl->getDeclContext()->getParentSourceFile()` which is
more robust.
