This reverts commit 8247525471. While
correct, it has uncovered several issues in existing code bases that
need to be sorted out before we can land it again.
Fixes rdar://problem/57846390.
Today in far more cases we are using mangled strings to look up metadata at
runtime. If we do this for an objc class but for whatever reason we do not have
any other references to the class, the static linker will fail to link in the
relevant framework. The reason why this happens is that autolinking is treated
by the static linker as a hint that a framework may be needed rather than as a
"one must link against the framework". If there aren't any undefined symbols
needed by the app from that framework, the linker just will ignore the hint. Of
course this then causes the class lookup to fail at runtime when we use our
mangled name to try to lookup the class.
I included an Interpreter test as well as IRGen tests to make sure that we do
not regress here in the future.
NOTE: The test modifications here are due to my moving the ObjCClasses framework
out of ./test/Interpreters/Inputs => test/Inputs since I am using it in the
IRGen test along side the interpreter test.
rdar://56136123
SIL already does this where necessary, except with foreign throwing
functions; this patch changes Sema and the ClangImporter to give
them an ObjCBool foreign error result type explicitly.
This fixes a problem where calls to functions taking and returning
the C99 _Bool type were miscompiled on Mac OS X x86-64, because
IRGen was conflating the Objective-C BOOL type (which is a signed
char on some platforms) and C99 _Bool (which lowers as the LLVM
i1 type).
Fixes <rdar://problem/26506458> and <rdar://problem/27365520>.
