The module-scope lookup tables use the same code for adding
module-scope declarations as for adding member operators, which are
found via "global" operator lookup. This requires us to expand macros
that can produce members of types, which violates the outside-in
expansion rule described in the proposals.
Stop recording member-producing macros, whether they are peer macros
applied to member declarations or are freestanding declaration macros
within a member context. This re-establishes the outside-in expansion
rule. It also means that member operators introduced by macro
expansion won't be found by global operator lookup, which is a
(necessary) semantic change.
Well, this is fun. Due to the use of the module-scope lookup table to
find operators, we need to carefully filter out any macro-introduced
declarations that *aren't* operators when forming the module-scope
lookup table. Otherwise, we can find macro-introduced static entities
within types... from completely unrelated scopes.
Fixes rdar://109219036.
Lazy member loading has been in use and the default for several years
now. However, the lazy loading was disabled for any type whose primary
definition was parsed even though some of its extensions could have
been deserialized, e.g., from a Clang module. Moreover, the non-lazy
path walked all of the extensions of such a type for all member name
lookup operations. Faced with a large number of extensions to the same
type (in my example, 6,000), this walk of the list of the extensions
could dominate type-checking time.
Eliminate all effects of the `-disable-named-lazy-member-loading`
flag, and always use the "lazy" path, which effectively does no work
for parsed type definitions and extensions thereof. The example with
6,000 extensions of a single type goes from type checking in 6 seconds
down to type checking in 0.6 seconds, and name lookup completely
disappears from the profiling trace.
The deleted tests relied on the flag that is now inert. They aren't by
themselves providing much value nowadays, and it's better to have the
simpler (and more efficient) implementation of member name lookup be
the only one.
'MacroExpansionDecl' and 'MacroExpansionExpr' have many common methods.
Introduce a common base class 'FreestandingMacroExpansion' that holds
'MacroExpansionInfo'.
Factor out common expansion logic to 'evaluateFreestandingMacro'
function that resembles 'evaluateAttachedMacro'.
Direct lookup relied in primary file checking to have filled in the
protocol type stored in the ImplementsAttr. This was already wrong
with multi-file test cases in non-WMO mode, and crashed in the
ASTPrinter if printing a declaration in a non-primary file.
I don't have a standalone test case that is independent of my
upcoming ASTPrinter changes, but this is a nice cleanup regardless.
This can't happen yet, but with an upcoming change, we hit an infinite
recursion here with PackExpansionType::get() -> getReducedShape()
-> mapTypeIntoContext() -> PackExpansionType::get().
It's fine to have the empty generic signature and non-empty
substitution map here. Also, correctly handle an input
generic signature with non-canonical generic parameter types.
API development sometimes requires a redesign while supporting early
adopters. Currently this is done by adding @_spi(name) to the API but
that requires adding the attribute in import statements as well, causing
manual overhead of adding and then removing when the redesign is done.
This PR introduces a special spi group name '_' and allows an implicit
spi import of a module containing API attributed with '@_spi(_)'
Resolves rdar://109797632
Unfortunately, I don't have reduced reproduction for the crash that motivated
this fix, but similar precautions are taken elsewhere when handling
PatternBindingDecls.
Keep track of those types and extensions that have any macro expansions,
so that when we need to check whether to expand macros to satisfy name
lookup, we only look through that list---rather than looking at every
extension again.
This improves compile times significantly for a source file with a
large number of extensions on a single type. However, there is still
much to do here.
Keep track of which types/extensions have members that could be produced by
a macro expansion, including the names of those members. Use this to
avoid walking into extensions or type definitions to expand macros
when they don't have any related macros.
Setting closure and local discriminators depends on an in-order walk
of the AST. For macros, it was walking into both macro expansions and
arguments. However, this doesn't work well with lazy macro expansions,
and could result in some closures/local variables not getting
discriminators set at all.
Make the assignment of discriminators only walk macro arguments, and
then lazily assign discriminators for anything within a macro
expansion or in ill-formed code. This replaces the single global "next
autoclosure discriminator" scheme with a per-DeclContext scheme, that
is more reliable/robust, although it does mean that discriminators
of closures and locals within macro expansions are dependent on
ordering. That shouldn't matter, because these are local values.
Fixes rdar://108682196.
* Add @_used and @_section attributes for global variables and top-level functions
This adds:
- @_used attribute that flags as a global variable or a top-level function as
"do not dead-strip" via llvm.used, roughly the equivalent of
__attribute__((used)) in C/C++.
- @_section("...") attribute that places a global variable or a top-level
function into a section with that name, roughly the equivalent of
__attribute__((section("..."))) in C/C++.
Type-checking an operator requires look up of all of its decls regardless of
which access modifier is used before filtering. If one of them is a package
decl in an imported module that was built with package-name, but the use site
of the operator decl is in a module that is not built with package-name, it
currently crashes as it tries to access package context of the use site, which
is null. This PR checks if both decl site and use site have package contexts
before accessing the package name property, otherwise return false to be filtered
out.
Resolves rdar://108961906
