The layouts of resilient value types shipped in the Swift 5 standard library
x and overlays will forever be frozen in time for backward deployment to old
Objective-C runtimes. This PR ensures that even if the layouts of these types
evolve in the future, binaries built to run on the old runtime will continue
to lay out class instances in a manner compatible with Swift 5.
Fixes <rdar://problem/45646886>.
This makes resolving mangled names to nominal types in the same module more efficient, and for eventual secrecy improvements, also allows types in the same module to be referenced from mangled typerefs without encoding any source-level name information about them.
Restructure the COFF metadata handling to use the linker section
grouping to emit section start/stop markers in the appropriate location.
This allows us to lookup the sections statically without having to the
walk the entire image structure.
Introduce a constructor for PE/COFF binaries. This will ensure that the
registration occurs for all modules appropriately. This should resolve
rdar://problem/19045112. The registration should occur prior to
`DllMain` being invoked from `DllMainCRTStartup`.
There was some duplication here, and also a potential
memory management issue; it appears that we were
converting a temporary std::string to a StringRef
when setting the section name of a global.
Ensure they get emitted at the end of the job by the dispatcher, and
also use a proper mangling and shared linkage for these symbols so
that if multiple threads emit the same descriptor it gets merged.
The new tests attempt to exercise these scenarios.
Fixes <rdar://problem/27906876>.
This consists of 3 parts:
1) Extend CallerAnalysis to also provide information if a function is partially applied
2) A new DeadArgSignatureOpt pass, similar to FunctionSignatureOpts, which just specializes for dead arguments of partially applied functions.
3) Let CapturePropagation eliminate such partial_apply instructions and replace them with a thin_to_thick conversion of the specialized functions.
This optimzation improves benchmarks where static struct or class functions are passed as a closure (e.g. -20% for SortStrings).
Such functions have a additional metatype parameter. We used to create a partial_apply in this case, which allocates a context, etc.
But this is not necessary as the metatype parameter is not used in most cases.
rdar://problem/27513085
What I've implemented here deviates from the current proposal text
in the following ways:
- I had to introduce a FunctionArrowPrecedence to capture the parsing
of -> in expression contexts.
- I found it convenient to continue to model the assignment property
explicitly.
- The comparison and casting operators have historically been
non-associative; I have chosen to preserve that, since I don't
think this proposal intended to change it.
- This uses the precedence group names and higherThan/lowerThan
as agreed in discussion.
We have no need for the other LLVM code generators (after all the main principle
of this smoke test is to only text X86 on macOS).
To implement this I had to split a couple of IRGen tests that involved multiple
code generator into multiple tests so I could use different REQUIRES lines. This
would be a nice feature to add to lit.
COFF has restrictions on portable section length (8 characters). Use a FourCC
identifier for the section on COFF. Take the opportunity to replace a
std::string parameter with a StringRef.
