This allows building the Swift standard library for targets which may
not have an actual OS running. This is identified by the OS field in
the target triple being set to `none`.
`getValue` -> `value`
`getValueOr` -> `value_or`
`hasValue` -> `has_value`
`map` -> `transform`
The old API will be deprecated in the rebranch.
To avoid merge conflicts, use the new API already in the main branch.
rdar://102362022
Swiftc port of https://github.com/apple/llvm-project/pull/4207.
This introduces a new flag, `-file-prefix-map` which can be used
instead of the existing `-debug-prefix-map` and `-coverage-prefix-map`
flags, and also remaps paths in index information currently.
This change removes the -emit-cxx-header option, and adds a new -emit-clang-header-path option instead. It's aliased to -emit-objc-header-path for now, but in the future, -emit-objc-header-path will alias to it. After this change Swift can start emitting a single header file that can be expose declarations to C, Objective-C, or C++. For now C++ interface is generated (for all public decls) only when -enable-cxx-interop flag is passed, but that behavior will change once attribute is supported.
This change causes the cache to be layered with a local "cache" that wraps the global cache, which will serve as the source of truth. The local cache persists only for the duration of a given scanning action, and has a store of references to dependencies resolved as a part of the current scanning action only, while the global cache is the one that persists across scanning actions (e.g. in `DependencyScanningTool`) and stores actual module dependency info values.
Only the local cache can answer dependency lookup queries, checking current scanning action results first, before falling back to querying the global cache, with queries disambiguated by the current scannning action's search paths, ensuring we never resolve a dependency lookup query with a module info that could not be found in the current action's search paths.
This change is required because search-path disambiguation can lead to false-negatives: for example, the Clang dependency scanner may find modules relative to the compiler's path that are not on the compiler's direct search paths. While such false-negative query responses should be functionally safe, we rely on the current scanning action's results being always-present-in-the-cache for the scanner's functionality. This layering ensures that the cache use-sites remain unchanged and that we get both: preserved global state which can be queried disambiguated with the search path details, and an always-consistent local (current action) cache state.
This commit adds support for the -lto_library flag, allowing users to specify a custom LTO library on Darwin. This also fixes an issue where the default LTO library is used even if Driver is run from inside an alternate toolchain.
Gather 'round to hear tell of the saga of autolinking in incremental
mode.
In the beginning, there was Swift code, and there was Objective-C code.
To make one import bind two languages, a twinned Swift module named the same as an
Objective-C module could be imported as an overlay. But all was not
well, for an overlay could be created which had no Swift content, yet
required Swift symbols. And there was much wailing and gnashing of teeth
as loaders everywhere disregarded loading these content-less Swift
libraries.
So, a solution was found - a magical symbol _swift_FORCE_LOAD_$_<MODULE>
that forced the loaders to heed the dependency on a Swift library
regardless of its content. It was a constant with common linkage, and it
was good. But, along came COFF which needed to support autolinking but
had no support for such matters. It did, however, have support for
COMDAT sections into which we placed the symbol. Immediately, a darkness
fell across the land as the windows linker loudly proclaimed it had
discovered a contradiction: "_swift_FORCE_LOAD_$_<MODULE> cannot be
a constant!", it said, gratingly, "for this value requires rebasing."
Undeterred, we switched to a function instead, and the windows linker
happily added a level of indirection to its symbol resolution procedure
and all was right with the world.
But this definition was not all right. In order to support multiple
translation units emitting it, and to prevent the linker from dead
stripping it, Weak ODR linkage was used. Weak ODR linkage has the nasty
side effect of pessimizing load times since the dynamic linker must
assume that loading a later library could produce a more definitive
definition for the symbol.
A compromise was drawn up: To keep load times low, external linkage was
used. To keep the linker from complaining about multiple strong
definitions for the same symbol, the first translation unit in the
module was nominated to recieve the magic symbol. But one final problem
remained:
Incremental builds allow for files to be added or removed during the
build procedure. The placement of the symbol was therefore dependent
entirely upon the order of files passed at the command line. This was no
good, so a decree was set forth that using -autolink-force-load and
-incremental together was a criminal offense.
So we must compromise once more: Return to a symbol with common linkage,
but only on Mach-O targets. Preserve the existing COMDAT-friendly
approach everywhere else.
This concludes our tale.
rdar://77803299
When building a static library with debug information, do not create a
dSYM generation job as it cannot be executed on a non-image target.
This is important for the case where the single invocation is both the
compile and link job.
This was detected in conjunction with @gottesmm.
If the compiler arguments have errors in them (e.g. because a file with the same name is used twice), we can often still fulfill SourceKit requests because the compiler argument errors are only relevant for later stages of the compilation process.
Instead of bailing out early, do a best effor retrieving the compiler arguments that are valid and ignoring the errors.
Fixes rdar://77618144
The frontend supports this via new options -index-unit-output-path and
-index-unit-output-path-filelist that mirror -o and -output-filelist. These are
intended to allow sharing index data across builds in separate directories (so
different -o values) that are otherwise equivalent as far as the index data is
concerned (e.g. an ASAN build and a non-ASAN build) by supplying the same
-index-unit-output-path for both.
This change updates the driver to add these new options to the frontend
invocation 1) when a new "index-unit-output-path" entry is specified for one
or more input files in the -output-file-map json or 2) if -index-file is
specified, when a new -index-unit-output-path driver option is passed.
Resolves rdar://problem/74816412
In the legacy driver, these flags will merely be propagated to the
frontends to indicate that they should disable serialization of
incremental information in swift module files.
In the new driver, these flags control whether the Swift driver performs
an incremental build that is aware of metadata embedded in the module.
Kudos to David for coming up with our new marketing name: Incremental
Imports.
rdar://74363450
Add a new swift-frontend driver option that extract APIs in the swift
module and print in JSON format. This is to allow tooling to understand
and process swift APIs without the need to be a swift compiler or
understand swift module/AST.
Unlike the frontend, the driver doesn't account for any VFS overlays set up
by the -vfsoverlay option when processing its input files. It also errors
if any of those input files don't exist on the file system. This makes it
impossible to use a file that only exists in the VFS as input to the driver,
even though the same file would be handled without issue by the frontend.
If the file doesn't exist even accounting for the VFS the frontend emits
a missing file diagnostic, so this change just suppresses the existence
check for inputs when a -vfsoverlay option is present.
Resolves rdar://problem/72485443
