Specifically:
1. set_union_for_each. This is like std::for_each, but it visits its inputs
(which are assumed to be sorted/uniqued sets) in set_union order.
2. is_uniqued_and_sorted.
I also fixed several nits from Jordan.
This is an immutable data structure with the following properties:
1. All of the sets are sorted and can be iterated over.
2. It takes in a bump ptr allocator and uses that allocator for all
allocations.
3. All concatenation operations involve only one bump ptr allocation.
4. Since we are only storing pointers, the data structure does not need any
destructors to be invoked to be cleaned up. The bumpptrallocator memory just
needs to be freed.
I am going to use this to improve the compile time performance of ARC.
...because "build configuration" is already the name of an Xcode feature.
- '#if' et al are "conditional compilation directives".
- The condition is a "conditional compilation expression", or just
"condition" if it's obvious.
- The predicates are "platform conditions" (including 'swift(>=...)')
- The options set with -D are "custom conditional compilation flags".
(Thanks, Kevin!)
I left "IfConfigDecl" as is, as well as SourceKit's various "BuildConfig"
settings because some of them are part of the SourceKit request format.
We can change these in follow-up commits, or not.
rdar://problem/19812930
TypeAlignments.h predates this whole mess; it was used for types with
stronger alignment in PointerLikeTypeTraits than the old default of
"2 by fiat and assumption". All remaining forward-declared types are
AST types, so fold them into TypeAlignments.h.
(The one exception is SILTypeList.h, but that's already gone on master.)
To avoid future ODR issues, explicitly include TypeAlignments.h into
every header that defines a type it forward-declares.
I wish we could use partial specialization to provide PointerLikeTypeTraits
for all derived classes of Decl, TypeBase, etc, but that's not something
you can do in C++ if you don't control the traits class.
This is the first patch in a series that will allow new protocol
requirements to be added resiliently, with the runtime filling in
default implementations in witness tables.
First, this adds a new flag to the protocol descriptor indicating
that the protocol is resilient. In this case, there are two
additional fields, MinimumWitnessTableSizeInWords and
DefaultWitnessTableSizeInWords, followed by tail-allocated
default witnesses.
The swift_getGenericWitnessTable() entry point now fills in the
default witnesses from the protocol if the given witness table
template is smaller than the expected witness table size.
This also changes the layout of instantiated witness tables to move
the address point to the end of private data. Previously the private
data came after the requirements, but this meant that adding new
requirements would require sliding the private data at runtime and
accessing it indirectly. It is much simpler to access it from
negative offsets instead.
I updated IRGen to emit the new metadata, but currently all protocols
are flagged as not resilient, and default witnesses are not emitted;
this will come in a subsequent patch once some more plumbing is
in place.
To avoid generating GOT entries for references to protocols defined
in the current module, I had to add some hacks to the existing hack
for this. I'll hopefully clean this up in a principled manner later.
This will be used when emitting field 32-bit integers into field
records, which are likely to be small and benefit from this kind
of encoding. These can potentially also be used in other places
where we emit integer constants to save space.
Introduce a new "swift" build configuration that guards declarations
and statements with a language version - if the current language version
of the compiler is at least that version, the block will parse as normal.
For inactive blocks, the code will not be parsed an no diagnostics will
be emitted there.
Example:
#if swift(>=2.2)
print("Active")
#else
this code will not parse or emit diagnostics
#endif
https://github.com/apple/swift-evolution/blob/master/proposals/0020-if-swift-version.md
rdar://problem/19823607
We really want to apply offsets using wrapping (unsigned) arithmetic, albeit with sign extension. This is significant on 32-bit platforms, where "far" addresses could be more than 2GB apart, but still relative-referenced using 32-bit signed values, and offset addition could end up wrapping around. Factor the logic to add an offset to a pointer out into a function that performs the sacred casting dance to appease the UB gods.
We usually want to use 32-bit offsets, since we use them to reference other objects within the same small-code-model image. However, for data structures that are both compiler-generated and runtime-allocated, we may want to save the relocation in compile time, but need a full-width offset to be able to relatively reference things from the heap. NFC yet.
Decrease the size of nominal type descriptors and make them true-const by relative-addressing the other metadata they need to reference, which should all be included in the same image as the descriptor itself. Relative-referencing string constants exposes a bug in the Apple linker, which crashes when resolving relative relocations to coalesceable symbols (rdar://problem/22674524); work around this for now by revoking the `unnamed_addr`-ness of string constants that we take relative references to. (I haven't tested whether GNU ld or gold also have this problem on Linux; it may be possible to conditionalize the workaround to only apply to Darwin targets for now.)
Although omit-needless-words is almost entirely a Clang importer task,
there are a handful of other places in the compiler that will need to
query this flag as well. NFC for now; those changes will come soon.
Since resilience is a property of the module being compiled,
not decls being accessed, we need to record which types are
resilient as part of the module.
Previously we would only ever look at the @_fixed_layout
attribute on a type. If the flag was not specified, Sema
would slap this attribute on every type that gets validated.
This is wasteful for non-resilient builds, because there
all types get the attribute. It was also apparently wrong,
and I don't fully understand when Sema decides to validate
which decls.
It is much cleaner conceptually to just serialize this flag
with the module, and check for its presence if the
attribute was not found on a type.
Exposes the global warning suppression and treatment as errors
functionality to the Swift driver. Introduces the flags
"-suppress-warnings" and "-warnings-as-errors". Test case include.
Restores StoredDiagnosticInfo, which is useful to help distinguish
when the user explicitly modifies the behavior of a diagnostic vs
we're just picking up the default kind.
Adds some clarifying comments, and lays out the suppression workflow,
whereby different types of suppression (per-diagnostic, per-category,
etc) have different precedence levels.
