...but don't hook it up to anything yet.
This is the very very start of the module stability / textual
interfaces feature described at
https://forums.swift.org/t/plan-for-module-stability/14551/
For now I've just made it a frontend option (not a driver option),
which is good enough for testing.
This flag is based on Clang's -fdebug-prefix-map, which lets the user remap absolute paths in debug info. This is necessary for reproducible builds and allows debugging to work on a different machine than the one that built the code when paths to the source may be different.
This work-around is no longer needed now that the full fix landed in
https://github.com/apple/swift/pull/16615. The argument is left with a warning
to help with migration between compilers with the work-around and compilers with
the full fix (see also rdar://problem/40502379).
Fixes rdar://problem/40476573.
IRGen can introduce calls to type metadata accessors for types that
should not be visible to the current translate, which can manifest in
linker errors within a module (for references to private types when
whole module optimization is disabled) or across modules (for
references to private/internal types in another module). Introduce a
new compiler flag `-emit-public-type-metadata-accessors` that emits
all type metadata accessors with public linkage, to work around the
problem in affected projects. This flag is intended to go away once we
have a proper solution.
This bug has been around in Swift "forever", but compiling the
overlays using -enable-resilience has exacerbated the problem and
caused regressions. This is a short-term fix to
rdar://problem/40229755 while we work on the correct long-term fix.
When the supplementary-outputs file is written for an -index-file invocation it writes out the first input file
given in arguments instead of the input file that is provided by -index-file-path option. This then causes the frontend
index invocation to fail with an error because there is a mismatch in the primary input file and the input file that is written
in the supplementary-outputs file.
When generating a compiler invocation in driver::createCompilerInvocation()
we end up using filelists if the number of inputs is > 128 (to work around
command line arg limits). We never actually write them out though, and so
fail when parsing the frontend arguments that reference them.
As this function is called frequently by SourceKit and command line limits
aren't a concern here, this patch makes the 128 threshold value configurable
via a new -driver-filelist-threshold option. This is set to its maximum value
in driver::createCompilerInvocation() to ensure filelists aren't used. This
new option makes the existing -driver-use-filelists (that forces filelists to
be used) redundant as it's now equivalent to -driver-filelist-threshold=0.
Resolves rdar://problem/38231888
Adds a -working-directory option which can be used to modify how
relative paths are resolved. It affects all other paths used in driver
options (controlled by a new ArgumentIsPath flag on options) as well as
the contents of output file maps and auxilliary file paths generated
implicitly by the compiler itself.
rdar://37713856
