This sets the mostly expected Darwin default ABI options for these two
platforms. Active changes from these defaults for watchOS are in a later patch.
llvm-svn: 251708
Previously, __weak was silently accepted and ignored in MRC mode.
That makes this a potentially source-breaking change that we have to
roll out cautiously. Accordingly, for the time being, actual support
for __weak references in MRC is experimental, and the compiler will
reject attempts to actually form such references. The intent is to
eventually enable the feature by default in all non-GC modes.
(It is, of course, incompatible with ObjC GC's interpretation of
__weak.)
If you like, you can enable this feature with
-Xclang -fobjc-weak
but like any -Xclang option, this option may be removed at any point,
e.g. if/when it is eventually enabled by default.
This patch also enables the use of the ARC __unsafe_unretained qualifier
in MRC. Unlike __weak, this is being enabled immediately. Since
variables are essentially __unsafe_unretained by default in MRC,
the only practical uses are (1) communication and (2) changing the
default behavior of by-value block capture.
As an implementation matter, this means that the ObjC ownership
qualifiers may appear in any ObjC language mode, and so this patch
removes a number of checks for getLangOpts().ObjCAutoRefCount
that were guarding the processing of these qualifiers. I don't
expect this to be a significant drain on performance; it may even
be faster to just check for these qualifiers directly on a type
(since it's probably in a register anyway) than to do N dependent
loads to grab the LangOptions.
rdar://9674298
llvm-svn: 251041
This is almost entirely a matter of just flipping a switch. 99% of
the runtime support is available all the way back to when it was
implemented in the non-fragile runtime, i.e. in Lion. However,
fragile runtimes do not recognize ARC-style ivar layout strings,
which means that accessing __strong or __weak ivars reflectively
(e.g. via object_setIvar) will end up accessing the ivar as if it
were __unsafe_unretained. Therefore, when using reflective
technologies like KVC, be sure that your paths always refer to a
property.
rdar://23209307
llvm-svn: 250955
Specifically, handle under-aligned object references (by explicitly
ignoring them, because this just isn't representable in the format;
yes, this means that GC silently ignores such references), descend
into anonymous structs and unions, stop classifying fields of
pointer-to-strong/weak type as strong/weak in ARC mode, and emit
skips to cover the entirety of block layouts in GC mode. As a
cleanup, extract this code into a helper class, avoid a number of
unnecessary copies and layout queries, generate skips implicitly
instead of explicitly tracking them, and clarify the bitmap-creation
logic.
llvm-svn: 250919
I randomly came across this difference between AArch64 and other targets:
on the latter, we don't emit nil checks for known non-nil class method
calls thanks to r247350, but we still do for AArch64 stret calls.
They use different code paths, because those are special, as they go
through the regular msgSend, not the msgSend*_stret variants.
llvm-svn: 249205
Introduce an Address type to bundle a pointer value with an
alignment. Introduce APIs on CGBuilderTy to work with Address
values. Change core APIs on CGF/CGM to traffic in Address where
appropriate. Require alignments to be non-zero. Update a ton
of code to compute and propagate alignment information.
As part of this, I've promoted CGBuiltin's EmitPointerWithAlignment
helper function to CGF and made use of it in a number of places in
the expression emitter.
The end result is that we should now be significantly more correct
when performing operations on objects that are locally known to
be under-aligned. Since alignment is not reliably tracked in the
type system, there are inherent limits to this, but at least we
are no longer confused by standard operations like derived-to-base
conversions and array-to-pointer decay. I've also fixed a large
number of bugs where we were applying the complete-object alignment
to a pointer instead of the non-virtual alignment, although most of
these were hidden by the very conservative approach we took with
member alignment.
Also, because IRGen now reliably asserts on zero alignments, we
should no longer be subject to an absurd but frustrating recurring
bug where an incomplete type would report a zero alignment and then
we'd naively do a alignmentAtOffset on it and emit code using an
alignment equal to the largest power-of-two factor of the offset.
We should also now be emitting much more aggressive alignment
attributes in the presence of over-alignment. In particular,
field access now uses alignmentAtOffset instead of min.
Several times in this patch, I had to change the existing
code-generation pattern in order to more effectively use
the Address APIs. For the most part, this seems to be a strict
improvement, like doing pointer arithmetic with GEPs instead of
ptrtoint. That said, I've tried very hard to not change semantics,
but it is likely that I've failed in a few places, for which I
apologize.
ABIArgInfo now always carries the assumed alignment of indirect and
indirect byval arguments. In order to cut down on what was already
a dauntingly large patch, I changed the code to never set align
attributes in the IR on non-byval indirect arguments. That is,
we still generate code which assumes that indirect arguments have
the given alignment, but we don't express this information to the
backend except where it's semantically required (i.e. on byvals).
This is likely a minor regression for those targets that did provide
this information, but it'll be trivial to add it back in a later
patch.
I partially punted on applying this work to CGBuiltin. Please
do not add more uses of the CreateDefaultAligned{Load,Store}
APIs; they will be going away eventually.
llvm-svn: 246985
The patch is generated using this command:
$ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
work/llvm/tools/clang
To reduce churn, not touching namespaces spanning less than 10 lines.
llvm-svn: 240270
Now the GEP constant utility functions require the type to be explicitly
passed (since eventually the pointer type will be opaque and not convey
the required type information). For now callers can still pass nullptr
(though none were needed here in Clang, which is nice) if
convenienc/necessary, but eventually that will be disallowed as well.
llvm-svn: 233937
The extension has the following syntax:
__builtin_call_with_static_chain(Call, Chain)
where Call must be a function call expression and Chain must be of pointer type
This extension performs a function call Call with a static chain pointer
Chain passed to the callee in a designated register. This is useful for
calling foreign language functions whose ABI uses static chain pointers
(e.g. to implement closures).
Differential Revision: http://reviews.llvm.org/D6332
llvm-svn: 224167
Richard rejected my Sema change to interpret an integer literal zero in
a varargs context as a null pointer, so -Wsentinel sees an integer
literal zero and fires off a warning. Only CodeGen currently knows that
it promotes integer literal zeroes in this context to pointer size on
Windows. I didn't want to teach -Wsentinel about that compatibility
hack. Therefore, I'm migrating to C++11 nullptr.
llvm-svn: 223079
linkage related to generation of OBJC_SELECTOR_REFERENCES symbol
needed in generation of call to 'super' in a class method.
// rdar://18150301
llvm-svn: 216676
The main subtlety here is that the Darwin tools still need to be given "-arch
arm64" rather than "-arch aarch64". Fortunately this already goes via a custom
function to handle weird edge-cases in other architectures, and it tested.
I removed a few arm64_be tests because that really isn't an interesting thing
to worry about. No-one using big-endian is also referring to the target as
arm64 (at least as far as toolchains go). Mostly they date from when arm64 was
a separate target and we *did* need a parallel name simply to test it at all.
Now aarch64_be is sufficient.
llvm-svn: 213744
to be applied to class or protocols. This will direct IRGen
for Objective-C metadata to use the new name in various places
where class and protocol names are needed.
rdar:// 17631257
llvm-svn: 213167
These cases in particular were incurring an extra strlen() when we already knew
the length. They appear to be leftovers from when the interfaces worked with C
strings that have continued to compile due to the implicit StringRef ctor.
llvm-svn: 210403
