When we form an extension for a conformance macro, make sure to
register that extension as being part of the nominal type to which the
conformance macro is attached. This ensures that the conformance is
seen everywhere. Crucially, this ensures that that protocol
conformance table handles conformances that are implied by the
conformance macro. For example, a conformance macro that introduces a
`Hashable` conformance will also imply an `Equatable` conformance;
that wasn't happening before this change.
This is needed to make the `OptionSet` macro work fully.
Provide ASTWalker with a customization point to specify whether to
check macro arguments (which are type checked but never emitted), the
macro expansion (which is the result of applying the macro and is
actually emitted into the source), or both. Provide answers for the
~115 different ASTWalker visitors throughout the code base.
Fixes rdar://104042945, which concerns checking of effects in
macro arguments---which we shouldn't do.
The macro role argument presented an opportunity for callers to accidentally
invoke this request twice for the same macro with slightly different macro
roles passed in, which resulted in re-typechecking the macro arguments.
Instead, derive the corresponding macro roles from the macro reference syntax.
Global peer macro expansions are not injected into the AST. Instead, they
are visited as "auxiliary declarations" when needed, such as in the decl
checker and during SILGen. This is the same mechanism used for local property
wrappers and local lazy variables.
- Use the name lookup table instead of adding members from a macro expansion to the parent decl context.
- Require declaration macros to specify introduced names and used the declared names to guide macro expansions lazily.
Rather than trying to patch up the "basic" macro expansion context
that comes from the swift-syntax package, implement our own based
on the new SourceManager. Fixes the `location(of:)` operation.
Errors that were thrown out of a macro implementation were being
emitted and then lost. The result of this is a SILGen assertion later
on, if there were no other errors in the code.
Make sure we properly emit these diagnostics through the source
manager, which required fixing an issue in the offset computation used
for diagnostics.
Use the name mangling scheme we've devised for macro expansions to
back the implementation of the macro expansion context's
`getUniqueName` operation. This way, we guarantee that the names
provided by macro expansions don't conflict, as well as making them
demangleable so we can determine what introduced the names.
Add SourceManager that can keep track of multiple source file syntax
nodes along with their external representations. The source manager can
emit diagnostics into any of those files, including tracking any
explicitly "detached" syntax nodes used for macro expansion.
Make sure we detach syntax nodes before passing them to macro
implementations, so they cannot see more of the source file than they
are permitted. We hadn't been doing this before (by accident), and
doing so motivated the introduction of the SourceManager.
Additionally, perform operator folding on macro arguments as part of
detaching them. Macro clients shouldn't have to do this, and moreover,
when clients do this, they lose the ability to easily emit diagnostics
on the now-folded nodes.
scopes.
ASTScope lookup can no longer assume that all scopes are within the same source
file. Scope trees can now contain scopes that are in macro expansion buffers, which
live in different source files with independent source ranges from the root of a
given scope tree. To handle this when searching for a scope containing a given source
location, ASTScope lookup needs to walk up the chain of macro expansion buffers to find
the lowest common buffer in which to compare source locations.
This fixes a number of issues with unqualified lookup into and from within macro-expanded
code.
Attribute macros are expanded during AttachedSemanticAttrsRequest. This
change invokves the expansion, but it does nothing with the result yet.
The next step is to parse back in the attribute list, type check it, and
return the resulting attributes back to the request to add to the semantic
attribute list.
Accessor macros are attached macros (written with attribute syntax)
that can generate accessors for a property or subscript. Recognize
custom attributes that are accessor macros when written on a storage
declaration, and expand those macros.
This is very much a work in progress, and the result of the expansion
isn't yet parsed or wired into the AST.
Add support for freestanding declaration macros.
- Parse `@declaration` attribute.
- Type check and expand `MacroExpansionDecl`.
Known issues:
- Generic macros are not yet handled.
- Expansion does not work when the parent decl context is `BraceStmt`. Need to parse freestanding declaration macro expansions in `BraceStmt` as `MacroExpansionDecl`, and add expanded decls to name lookup.
With macro expansions, and really any code generation that produces
proper source locations, the parent source file of a declaration
context will be a generated source file rather than the source file
near the top of the declaration-context stack. Adjust the
implementation of `getParentSourceFile()` to return that innermost
source file by doing location-based lookup.
"Relink" the folded syntax node back into the primary syntax node. When
we do this, we get consistent source locations that do not require any
adjustment.
Test this by adding a Fix-It to the silly AddBlocker macro, replacing
the `+` with a `-`.
