This commit adds -lto flag for driver to enable LTO at LLVM level.
When -lto=llvm given, compiler emits LLVM bitcode file instead of object
file and perform thin LTO using libLTO.dylib plugin.
When -lto=llvm-full given, perform full LTO instead of thin LTO.
Clang provides options to override that default value.
These options are accessible via the -Xcc flag.
Some Swift functions explicitly disable the frame pointer.
The clang options will not override those.
This default formatting style remains the same "LLVM style". "Swift style"
is what was previously enabled via -enable-experimental-diagnostic-formatting
Add a mode bit to the dependency collector that respects the frontend flag in the previous commit.
Notably, we now write over the dependency files at the end of the compiler pipeline when this flag is on so that dependency from SILGen and IRGen are properly written to disk.
Move the playground and debugger transforms out
of the Frontend and into `performTypeChecking`, as
we'd want them to be applied if
`performTypeChecking` was called lazily.
Some code paths that see target triples go through the frontend
without seeing the driver. Therefore, perform the same "simulator"
inference for x86 iOS/tvOS/watchOS triples also in the frontend,
to ensure that we remain compatible. Also make sure that
-print-target-info performs the appropriate adjustment.
`-no-warnings-as-errors`
This functionality is required for build systems to be able to overload/disable a given Swift project's preference of treating warnings as errors.
Resolves rdar://problem/35699776
Some code paths that see target triples go through the frontend
without seeing the driver. Therefore, perform the same "simulator"
inference for x86 iOS/tvOS/watchOS triples also in the frontend,
to ensure that we remain compatible. Also make sure that
-print-target-info performs the appropriate adjustment.
Teach the driver to pass the SDK version it computes (from the SDK
settings JSON in a Darwin-based platform's SDK) down into the frontend.
The frontend then sets that SDK version in the LLVM module, which
eventually makes its way into the Mach-O file.
Last part of rdar://problem/60332732.
