Currently symbol graphs are always written in files that contain 1 to 2
module names. It's possible for Swift module names to be very long, so
combining 2 of them in file name like `module1@module2...` in the same
path component means the name can be too long for some file systems. The
new option `-symbol-graph-shorten-output-names` changes the symbol graph
output files to use a MD5 hash of the module name(s) as the filename and
outputs an additional JSON file with the original names mapped to the
real filename. The module names JSON can be used to construct a VFS
overlay with the original naming scheme.
fix#83723
I considered using vfsoverlay, which seems like a viable solution, but
the vfsoverlay options don't seem to apply to any of the outputs from
the compiler. When I set an overlay to remap the symbol graph file
outputs, the remapped external paths aren't used so the root problem of
too long file names remains.
This includes:
- bumping the SWIFT_SYMBOLGRAPH_FORMAT_MINOR version
- introduction of the "swift.extension" symbol and "extensionTo" relationship
- adding support for ExtensionDecl to the Symbol class
- adding a "typeKind" field to the symbol's extension mixin which indicates what kind
of symbol was extended
- intoduction of the -emit-extension-block-symbols flag, which enables the behavior
outlined below
- adaptions to SymbolGraphASTWalker that ensure a swift.extension symbol is emitted
for each extension to a type that does not exist in the local symbol graph
- adaptions to SymbolGraph and SymbolGraphASTWalker that ensure member and conformance
relationships are correctly associated with the swift.extension symbol instead of
the original type declaration's (extended nominal's) symbol where applicable
- adaptions to SymbolGraphASTWalker that ensure swift.extension symbols are connected
to their respective extended nominal's symbol using an extensionTo relationship
Testing:
- adds SymbolGraph tests that test behavior only relevant in
-emit-extension-block-symbols mode
- adapts some SymbolGraph tests to additionally test similar behavior for
extensions to external types in -emit-extension-block-symbols mode
- adapts some SymbolGraph tests to (additionally or exclusively) test the
behavior with -emit-extension-block-symbols mode enabled
Bugfixes:
- fixes a bug where some conformsTo relationships implicated by the conformances
declared on an extension to an external type were not emitted
(see test/SymbolGraph/Relationships/ConformsTo/Indirect.swift)
Further changes:
- documents the strategy for naming and associating children declared in extensions
to typealiases (see test/SymbolGraph/Relationships/MemberOf/Typealias.swift,
test/SymbolGraph/Symbols/Names.swift)
This currently doesn't check for inherited docs, ie. either the
imported declaration has docs or it doesn't. There's also a few odd
cases with mixed doc types and when each line is prefixed with '*', but
it's good enough for an initial implementation.
Moves UTF8 sanitisation out of ASTPrinter.h and into Unicode.h so that
it can be used here as well.
Resolves rdar://91388603.
Emit copies of default implementations in protocol extensions and superclass declarations in conforming types and subclasses respectively using a virtual USR, i.e. `${REAL_USR}::SYNTHESIZED::${CONFORMING_OR_SUBCLASS_TYPE_USR}`.
- Add a -skip-synthesized-members option to skip these synthesized members.
- Create a new wrapping `Symbol` type that can also contain a base type declaration as well as the inherited declaration for those synthesized cases. Move some symbol-specific APIs there.
- Doc comments can “cascade” down to protocol extensions or refinements in concrete types. When emitting the doc comment for a symbol, look up through to superclasses or protocol requirements for where a doc comment is actually written.
- Clean up filtering of implicitly private (e.g. “public underscored”) types
rdar://problem/59128787
