Add module context to all declarations. As keeping the `std::variant`s
required slightly more work for this, and we intended to remove them
any way, this is done in this change.
For background, we put those in as we were not extracting all modules at
the time, so we were missing some DB ids that we put back in by adding
the "defining" traps not only in the trap file related to the defining
module but also to the one where the declaration was used. Since then
we fixed module extraction, so this should not be needed any more.
This introduces a `MethodRefExpr` node synthesized out of
`DotSyntaxCallExpr` under the `LookupExpr` hierarchy. This means that
much like
```free_function(1, 2)```
is a `CallExpr` with `getFunction` giving a `DeclRefExpr`,
```foo.method(1, 2)```
is now a `CallExpr` with `getFunction` giving a `MethodRefExpr`.
`ApplyExpr::getStaticTarget` has been made work with it (as well as
`ConstructorRefCallExpr` which for the moment has been left where it
is), a new `MethodApplyExpr` has been introduced deriving from it,
and control and data flow libraries have adapted.
A small but was fixed in `qlgen` where the default constructor for DB
types was not correctly subtracting derived IPA types depending on the
order of definitions in `schema.yml`.
There are still some occurrences of `DotSyntaxCallExpr`, and as already
mentioned the other `SelfApply` class (`ConstructorRefCallExpr`) was
left alone. Their treatment is left for a future PR.
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.
Now `TypeRepr` is a final class in the AST, which is more or less just
a type with a location in code.
As the frontend does not provide a direct way to get a type from a
type representation, this information must be provided when fetching
the label of a type repr.
This meant:
* removing the type repr field from `EnumIsCaseExpr`: this is a virtual
AST node introduced in place of some kinds of `IsEpxr`. The type
repr is still available from the `ConditionalCheckedCastExpr` wrapped
by this virtual node, and we will rebuild the original `IsExpr` with
the IPA layer.
* some logic to get the type of keypath roots has been added to
`KeyPathExpr`. This was done to keep the `TypeRepr` to `Type` relation
total in the DB, but goes against the design of a dumb extractor. The
logic could be moved to QL in the future
* in the control flow library, `TypeRepr` children are now ignored. As
far as I can tell, there is no runtime evaluation going on in
`TypeRepr`s, so it does not make much sense to have control flow
through them.
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.
The `getName` in `Type.qll` was issuing a warning in other generated
classes having a `getName` from a `name` property in `schema.yml`.
To fix the possible inconsistency, `diagnostic_name` is being renamed to
`name` in the schema. Despite the scary doc comment on
`swift::Type::getString` (namely `for use in diagnostics only`), that
seems to be the right generic naming mechanism for types, and it
coincides with the name we were extracting on types with an explicit
`name` property.
In case we find a case where `Type::getString` gives something wrong,
we can probably just patch it on that specific type class.
This new class encompasses both `AbstractFunctionDecl` and
`AbstractClosureExpr`, together with their common parts (namely
parameters and the body).
`ClosureExpr` and `AutoClosureExpr` got ported to structured C++
generated translation in the process.
By explicitly marking children in the `schema.yml` file, an internal
`getAChild` predicate is implemented, that is in turn used in `AstNode`
to implement `getParent`.
This is yet to be used in the control flow library to replace the
hand-rolled implementation.
A further, more complex step is to use the same information to fully
generate the core implementation of `PrintAst` (including the
accessor string). This will be done later.
The `parent` tests use the same swift code as the extractor tests, and
this is currently enforced by `sync-files.py`. Notice that `qltest.sh`
had to be modified to deal with multiple files, which was not working
yet.
This transfers the current state of `StmtVisitor` in the PoC, plus some
changes required for the update to swift 5.6.
Also `getLabel` in `SwiftDispatcher` got renamed to `createLabel`, and
is now correctly outputting the label assignment to the trap file.
This transfers the current state of `DeclVisitor` from the
proof-of-concept.
TODO: make the `declarations` tests in `extractor-tests` more
comprehensive.
This allows to avoid bypassing label type correcness in the extractor,
and allows to independently resolve TBD extractions, as with this
approach TBD nodes do have the correctly typed trap label. The TBD
status is now a predicate on the QL side.
This requires:
* a default visit using the correct type, which is achieved via macro
metaprogramming in `VisitorBase.h`, following the way
`swift::ASTVisitor` is programmed
* a mapping from labels to corresponding binding trap entries. The
functor is defined in `TrapTagTraits.h` and instantiated in generated
`TrapEntries.h`
* Binding trap entries for TBD unknown entities must not have any other
field than the `id` (after all, we are supposed to not extract them
yet). This is why all unextracted fields in `schema.yml` have been
commented out, and will be uncommentend when visitors are added
Properties marked with `predicate` in the schema are now accepted.
* in the dbscheme, they will translate to a table with a single `id`
column (and the table name will not be pluralized)
* in C++ classes, they will translate to `bool` fields
* in QL classes, they will translate to predicates
Closes https://github.com/github/codeql-c-team/issues/1016
