This makes Swift (a) more likely to prefer frameworks over bare headers,
reducing potential issues with non-modular headers, and (b) more likely
to fail in the same way as LLDB if the -Xcc options also contain or affect
search paths.
rdar://problem/22413525
Swift SVN r31950
We can't know the number of search paths provided to %target-swift-build
in advance, but we /can/ make sure they're not duplicated.
Follow-up to rdar://problem/20291720
Swift SVN r27218
Now that we can pick up search paths from frameworks (necessary to debug
them properly), we can end up with exponential explosions leading to the
same search path coming up thousands of times, which destroys compilation
time /and/ debugger responsiveness. This is already hitting people with
frameworks compiled for app extensions (due to a mistaken approximation
of whether or not something is a framework), but we're turning this on for
all frameworks in the immediate future.
rdar://problem/20291720
Swift SVN r27087
There's also a testing option, -serialize-debugging-options, to force this
extra info to be serialized even for library targets. In the long run we'll
probably write out this information for all targets, but strip it out of
the "public module" when a framework is built. (That way it ends up in the
debug info's copy of the module.)
Incidentally, this commit includes the ability to add search paths to the
Clang importer on the fly, which is most of rdar://problem/16347147.
Unfortunately there's no centralized way to add search paths to both Clang
/and/ Swift at the moment.
Part of rdar://problem/17670778
Swift SVN r24545
