Add a fast path to create swift CompilerInstance when it is only used to
replay output when there is a cache hit. The normal `setup` function is
very expensive to call, especially in cache mode to setup inputs, and it
needs to be called once per input file from libSwiftScan API due to the
current caching granularity.
The fast path will only construct the part that is needed for output
replay, including the CAS, the output backend and caching diagnostic
processor.
rdar://127062609
LLVM is gearing up to move to `std::endianness` and as part of that has
moved `llvm::support::endianness` to `llvm::endianness`
(bbdbcd83e6702f314d147a680247058a899ba261). Rename our uses.
The response file expansion function doesn't return all the arguments
allocated using StringSaver produced. It only use the StringSaver to
save the newly expanded arguments. Need to make sure all the original
arguments are saved so they can be used later during replay.
rdar://121808135
Build system can pass response file to libSwiftScan as the command-line
arguments. libSwiftScan needs to expand the response file before
performing tasks.
rdar://121291342
`llvm::cl::ParseCommandLineOptions()` is not thread-safe to be called
from libSwiftScan so replaying multiple commands in parallel can crash
the build system. Since the replay instance is not used for compilation
and only need information from command-line arguments to create outputs
and diagnostics, ignore LLVMArgs when replaying.
rdar://120423882
Avoid path encoding difference (for example, real_path vs. path from
symlink) by eliminating the path from cache key. Cache key is now
encoded with the index of the input file from all the input files from
the command-line, reguardless if those inputs will produce output or
not. This is to ensure stable ordering even the batching is different.
Add a new cache computation API that is preferred for using input index
directly. Old API for cache key is deprecated but still updated to
fallback to real_path comparsion if needed.
As a result of swift scan API change, rename the feature in JSON file to
avoid version confusion between swift-driver and libSwiftScan.
rdar://119387650
Add a new async download API from CASID. This helps build system better
schedule the job/remove duplicated downloads, than using an opaque
cached_output handle.
Add new APIs libSwiftScan that can be used for cache query and cache
replay. This enables swift-driver or build system to query the cache and
replay the compilation results without invocation swift-frontend for
better scheduling.
