need to provide a 'dominating IP' which is guaranteed to
dominate the (de)activation point but which cannot be avoided
along any execution path from the (de)activation point to
the push-point of the cleanup. Using the entry block is
bad mojo.
llvm-svn: 144276
a previously-inactive cleanup, not only do we need a
flag variable, but we should also force the cleanup to
query the flag variable. However, we only need to do
this when we're activating in a context that's
conditionally executed; otherwise, we may safely
assume that the cleanup is dominated by the activation
point.
llvm-svn: 144271
full-expression. Naturally they're inactive before we enter
the block literal expression. This restores the intended
behavior that blocks belong to their enclosing scope.
There's a useful -O0 / compile-time optimization that we're
missing here with activating cleanups following straight-line
code from their inactive beginnings.
llvm-svn: 144268
block-typed __block variables using objc_retainBlock
and objc_dispose. Previously we were using
_Block_object_assign and _Block_object_destroy
with BLOCK_BYREF_CALLER, which causes the runtime
to completely ignore the retain and release.
In most cases this doesn't cause catastrophe
because the retain/release are balanced and
because the block in the variable was copied
upon assignment there. However, the stack
copy of the variable will be released when
it goes out of scope, which is a problem if
that value was released due to an assignment
to the heap copy. Similarly, a leak can occur
if the variable is assigned after the copy to
the heap.
llvm-svn: 144162
non-fragile ABI we may not be able to lay out the type and the debugger
would ignore us even if we did put in the offset. Go ahead and just
put any value there and don't look up the offset since it may not exist.
rdar://10210157
llvm-svn: 141261
increasingly prevailing case to the point that new features
like ARC don't even support the fragile ABI anymore.
This required a little bit of reshuffling with exceptions
because a check was assuming that ObjCNonFragileABI was
only being set in ObjC mode, and that's actually a bit
obnoxious to do.
Most, though, it involved a perl script to translate a ton
of test cases.
Mostly no functionality change for driver users, although
there are corner cases with disabling language-specific
exceptions that we should handle more correctly now.
llvm-svn: 140957
calls, or calls to audited functions without an explicit
return attribute, to be casted without a bridge cast.
Tie this mechanism in with the existing exceptions to
the cast restrictions. State those restrictions more
correctly and generalize.
llvm-svn: 140912
This model uses the 'landingpad' instruction, which is pinned to the top of the
landing pad. (A landing pad is defined as the destination of the unwind branch
of an invoke instruction.) All of the information needed to generate the correct
exception handling metadata during code generation is encoded into the
landingpad instruction.
The new 'resume' instruction takes the place of the llvm.eh.resume intrinsic
call. It's lowered in much the same way as the intrinsic is.
llvm-svn: 140049
This is consistent with the behavior of assigning into a __strong l-value,
and it's also necessary for ensuring that the ivar doesn't end up a dangling
reference. We decided not to change the behavior of "retain" properties, but
just to make them warnings/errors when of block type.
llvm-svn: 139619
even on architectures that support unaligned access (which is the
only way this is otherwise legal, given that ivars apparently do
not honor alignment attributes).
llvm-svn: 139590
single code path. Use atomic loads and stores where necessary. Load and
store anything of the appropriate size and alignment with primitive
operations instead of going through the call.
llvm-svn: 139580
the lifetime of the block by copying it to the heap, or else we'll get
a dangling reference because the code working with the non-block-typed
object will not know it needs to copy.
There is some danger here, e.g. with assigning a block literal to an
unsafe variable, but, well, it's an unsafe variable.
llvm-svn: 139451
__block variables where the act of initialization/assignment
itself causes the __block variable to be copied to the heap
because the variable is of block type and is being assigned
a block literal which captures the variable.
rdar://problem/9814099
llvm-svn: 136337
for-in statements; specifically, make sure to close over any
temporaries or cleanups it might require. In ARC, this has
implications for the lifetime of the collection, so emit it
with a retain and release it upon exit from the loop.
rdar://problem/9817306
llvm-svn: 136204
Introduce and document a new objc_returns_inner_pointer
attribute, and consume it by performing a retain+autorelease
on message receivers when they're not immediately loaded from
an object with precise lifetime.
llvm-svn: 135764
methods, including indirectly overridden methods like those
declared in protocols and categories. There are mismatches
that we would like to diagnose but aren't yet, but this
is fine for now.
I looked at approaches that avoided doing this lookup
unless we needed it, but the infer-related-result-type
checks were doing it anyway, so I left it with the same
fast-path check for no previous declartions of that
selector.
llvm-svn: 135743
block pointers) that don't have any qualification to be POD types. We
were previously considering them to be non-POD types, because this was
convenient in C++ for is_pod-like traits. However, we now end up
inferring lifetime in such cases (template arguments infer __strong),
so it is not necessary.
Moreover, we want rvalues of object type (which have their lifetime
stripped) to be PODs to allow, e.g., va_arg(arglist, id) to function
properly. Fixes <rdar://problem/9758798>.
llvm-svn: 134993
caused us to skip layout out a function accurately. If
so, flush the type cache for both the function and struct
case to ensure that any pointers to the functions get
recomputed. This is overconservative, but with this patch
clang can build itself again.
llvm-svn: 134863
conservative when converting a functiontype to IR when in a "pointer within
a struct" context. This has the unfortunate sideeffect of compiling all
function pointers inside of structs into "{}*" which, though correct, is
ugly. This has the positive side effect of being correct, and it is pretty
straight-forward to improve on this.
llvm-svn: 134861
- Emit default-initialization of arrays that were partially initialized
with initializer lists with a loop, rather than emitting the default
initializer N times;
- support destroying VLAs of non-trivial type, although this is not
yet exposed to users; and
- support the partial destruction of arrays initialized with
initializer lists when an initializer throws an exception.
llvm-svn: 134784
where we have an immediate need of a retained value.
As an exception, don't do this when the call is made as the immediate
operand of a __bridge retain. This is more in the way of a workaround
than an actual guarantee, so it's acceptable to be brittle here.
rdar://problem/9504800
llvm-svn: 134605
structure to hold inferred information, then propagate each invididual
bit down to -cc1. Separate the bits of "supports weak" and "has a native
ARC runtime"; make the latter a CodeGenOption.
The tool chain is still driving this decision, because it's the place that
has the required deployment target information on Darwin, but at least it's
better-factored now.
llvm-svn: 134453
existence by always threading an edge from the catchall. Not doing
this was previously causing a crash in the very extreme case where
neither the normal cleanup nor the EH catchall was actually reachable:
we would delete the catchall entry block, which would cause us to
delete the entry block of the finally cleanup as well because the
cleanup logic would merge the blocks, which in turn triggered an assert
because later blocks in the finally would still be using values from the
entry. Laziness turns out to be the most elegant solution to the problem.
llvm-svn: 133601
__builtin___CFStringMakeConstantString and CF typed function calls
with explicit cf_returns_retained/cf_returns_not_retained attributes.
// rdar://9544832
llvm-svn: 133535
they should still be officially __strong for the purposes of errors,
block capture, etc. Make a new bit on variables, isARCPseudoStrong(),
and set this for 'self' and these enumeration-loop variables. Change
the code that was looking for the old patterns to look for this bit,
and change IR generation to find this bit and treat the resulting
variable as __unsafe_unretained for the purposes of init/destroy in
the two places it can come up.
llvm-svn: 133243
Language-design credit goes to a lot of people, but I particularly want
to single out Blaine Garst and Patrick Beard for their contributions.
Compiler implementation credit goes to Argyrios, Doug, Fariborz, and myself,
in no particular order.
llvm-svn: 133103
to be careful to emit landing pads that are always prepared to handle a
cleanup path. This is correct mostly because of the fix to the LLVM
inliner, r132200.
llvm-svn: 132209
parameter types to be ill-formed. However, it relies on the
completeness of method parameter types when producing metadata, e.g.,
for a protocol, leading IR generating to crash in such cases.
Since there's no real way to tighten down the semantics of Objective-C
here without breaking existing code, do something safe but lame:
suppress the generation of metadata when this happens.
Fixes <rdar://problem/9123036>.
llvm-svn: 132171
send if the receiver is null. Normally it's not worthwhile to check this,
but avoiding the null-initialization is nice, and this also avoids nasty
problems where the null-initialization is visible within the call because
we use an aliased result buffer. rdar://problem/9402992
llvm-svn: 131366
Go through and expand the members of bases into the encoding string (and encode the VTable as well).
Unlike gcc which expands virtual bases as many times as they appear in the
hierarchy, clang will only expand them once at the end, to reflect the actual layout.
Note that there doesn't seem to be a way to indicate in the encoding that
packing/alignment of members is different that normal, in which case
the encoding will be out-of-sync with the real layout.
If the runtime switches to just consider the size of types without
taking into account alignment, we could easily make padding explicit in the
encoding (e.g. using arrays of chars). The encoding strings would be
longer then though.
Also encode a flexible array member as array of 0 size, like gcc, not as a pointer.
llvm-svn: 131365
Ivar offsets for synthesized ivars are wrong, which could end up with a large
number of dirty pages because of ivar fixups at runtime. When we pack all of the
synthesized ivars into the same section, it limits the number of dirty pages
created. Place them in the "__DATA,__objc_ivar" section.
<rdar://problem/9374905>
llvm-svn: 130870
ObjC NeXt runtime where method pointer registered in
metadata belongs to an unrelated method. Ast part of this fix,
I turned at @end missing warning (for class
implementations) into an error as we can never
be sure that meta-data being generated is correct.
// rdar://9072317
llvm-svn: 130019
there is no reason to align them higher.
- This roughly matches llvm-gcc's r126913.
- It is an open question whether or not we should do this for cstring's in
general (code size vs optimization potential), for now we just match llvm-gcc
until someone wants to run some experiments.
llvm-svn: 129410
because the result is ignored. The particular example here is with
property l-values, but there could be all sorts of lovely casts that this
isn't safe for. Sink the check into the one case that seems to actually
be capable of honoring this.
llvm-svn: 129397
platform implies default visibility. To achieve these, refactor our
lookup of explicit visibility so that we search for both an explicit
VisibilityAttr and an appropriate AvailabilityAttr, favoring the
VisibilityAttr if it is present.
llvm-svn: 128336
accessed via the indirect pointer, they don't need to be pointers to pointers).
Finished moving the message lookup code into separate subclasses for each
runtime. Also performed a few smallish related tidies.
We're now bitcasting the result of the message lookup functions, rather than
casting the lookup functions themselves, so the messages.m test needed updating
to reflect this.
llvm-svn: 128180
which versions of an OS provide a certain facility. For example,
void foo()
__attribute__((availability(macosx,introduced=10.2,deprecated=10.4,obsoleted=10.6)));
says that the function "foo" was introduced in 10.2, deprecated in
10.4, and completely obsoleted in 10.6. This attribute ties in with
the deployment targets (e.g., -mmacosx-version-min=10.1 specifies that
we want to deploy back to Mac OS X 10.1). There are several concrete
behaviors that this attribute enables, as illustrated with the
function foo() above:
- If we choose a deployment target >= Mac OS X 10.4, uses of "foo"
will result in a deprecation warning, as if we had placed
attribute((deprecated)) on it (but with a better diagnostic)
- If we choose a deployment target >= Mac OS X 10.6, uses of "foo"
will result in an "unavailable" warning (in C)/error (in C++), as
if we had placed attribute((unavailable)) on it
- If we choose a deployment target prior to 10.2, foo() is
weak-imported (if it is a kind of entity that can be weak
imported), as if we had placed the weak_import attribute on it.
Naturally, there can be multiple availability attributes on a
declaration, for different platforms; only the current platform
matters when checking availability attributes.
The only platforms this attribute currently works for are "ios" and
"macosx", since we already have -mxxxx-version-min flags for them and we
have experience there with macro tricks translating down to the
deprecated/unavailable/weak_import attributes. The end goal is to open
this up to other platforms, and even extension to other "platforms"
that are really libraries (say, through a #pragma clang
define_system), but that hasn't yet been designed and we may want to
shake out more issues with this narrower problem first.
Addresses <rdar://problem/6690412>.
As a drive-by bug-fix, if an entity is both deprecated and
unavailable, we only emit the "unavailable" diagnostic.
llvm-svn: 128127
The prototype for objc_msgSend() is technically variadic -
`id objc_msgSend(id, SEL, ...)`.
But all method calls should use a prototype that matches the method,
not the prototype for objc_msgSend itself().
// rdar://9048030
llvm-svn: 126754
The prototype for objc_msgSend() is technically variadic -
`id objc_msgSend(id, SEL, ...)`.
But all method calls should use a prototype that matches the method,
not the prototype for objc_msgSend itself().
// rdar://9048030
llvm-svn: 126678
_Block_object_* flags; it's just BLOCK_HAS_COPY_DISPOSE or not.
Also, we don't need to chase forwarding pointers prior to calling
_Block_object_dispose; _Block_object_dispose in fact already does
this.
rdar://problem/9006315
llvm-svn: 125823
Nobody ever gave me a clear reason for why we were doing this, and
now it's apparently causing serious problems, so if *not* having this
causes problems, we get to solve them the right way this time.
llvm-svn: 125627
- BlockDeclRefExprs always store VarDecls
- BDREs no longer store copy expressions
- BlockDecls now store a list of captured variables, information about
how they're captured, and a copy expression if necessary
With that in hand, change IR generation to use the captures data in
blocks instead of walking the block independently.
Additionally, optimize block layout by emitting fields in descending
alignment order, with a heuristic for filling in words when alignment
of the end of the block header is insufficient for the most aligned
field.
llvm-svn: 125005
to allow us to explicitly control whether or
not Objective-C properties are default synthesized.
Currently this feature only works when using
the -fobjc-non-fragile-abi2 flag (so there is
no functionality change), but we can now turn
off this feature without turning off all the features
coupled with -fobjc-non-fragile-abi2.
llvm-svn: 122519
Also, move the l-value emission code into CGObjC.cpp and teach it, for
completeness, to store away self for a super send.
Also, inline the super cases for property gets and sets and make them
use the correct result type for implicit getter/setter calls.
llvm-svn: 120887
objc_exception_rethrow, so we don't...", since something is actually trying to
call this with the wrong signature (!). Unfortunately I don't understand the new
EH infrastructure well enough to fix it immediately.
llvm-svn: 116660
both @catches and a @finally, because the second call to @objc_exception_try_enter
will clobber the exception slot. Fixes rdar://problem/8440970.
llvm-svn: 115575
information when imported variable is used
more than once. Originally though to be a bug in importing
block varibles. Fixes radar 8417746.
llvm-svn: 113675
block-literal initializer expression causes IRgen to crash.
This patch fixes by saving it in StaticLocalDecl map
already used for such purposes. (radar 8390455).
llvm-svn: 113307
using the same methods as used for normal structures.
- This fixes problems with reading past the end of the structure and with
handling straddled bit-field access.
llvm-svn: 112914
instead of _Unwind_Resume. With SJLJ exceptions, this is spelled
"_Unwind_SjLj_Resume_or_Rethrow", not "_Unwind_SjLj_Resume", which has
significantly different semantics.
We should actually never be generating a call to _Unwind_SjLj_Resume directly;
even if we were generating true cleanups (which we aren't because of the
horrible hack), we should be calling __cxa_end_cleanup() on ARM. I
haven't implemented this because there's little point as long as the HH is
present.
I believe this fixes <rdar://problem/8281377>.
llvm-svn: 110851
where we weren't accounting for the possibility that a @finally block might
have internal cleanups and therefore might write to the cleanup destination slot.
Fixes <rdar://problem/8293901>.
llvm-svn: 110760
ObjC exceptions:
- don't enter a try for the catch blocks unless there's a finally
- put the setjmp buffer in the locals set for liveness reasons
- dump the sync object into an alloca in the locals set for liveness reasons
Some of this can go away if the backend starts to properly calculate liveness
in the presence of setjmp (which would also be a *much* stabler solution).
llvm-svn: 110188
the magic of inline assembly. Essentially we use read and write hazards
on the set of local variables to force flushing locals to memory
immediately before any protected calls and to inhibit optimizing locals
across the setjmp->catch edge. Fixes rdar://problem/8160285
llvm-svn: 109960
sections on", this change uncovered a possible linker bug which resulted in the
wrong messages getting dispatched. Backing this out while we investigate...
llvm-svn: 109817
use of property-dot syntax using 'super' as receiver
is 'void'. This fixes a bug in generating correct
API for setter call. Fixes radar 8203426.
llvm-svn: 109297
mostly in avoiding unnecessary work at compile time but also in producing more
sensible block orderings.
Move the destructor cleanups for local variables over to use lazy cleanups.
Eventually all cleanups will do this; for now we have some awkward code
duplication.
Tell IR generation just to never produce landing pads in -fno-exceptions.
This is a much more comprehensive solution to a problem which previously was
half-solved by checks in most cleanup-generation spots.
llvm-svn: 108270
self-host. Hopefully these results hold up on different platforms.
I tried to keep the GNU ObjC runtime happy, but it's hard for me to test.
Reimplement how clang generates IR for exceptions. Instead of creating new
invoke destinations which sequentially chain to the previous destination,
push a more semantic representation of *why* we need the cleanup/catch/filter
behavior, then collect that information into a single landing pad upon request.
Also reorganizes how normal cleanups (i.e. cleanups triggered by non-exceptional
control flow) are generated, since it's actually fairly closely tied in with
the former. Remove the need to track which cleanup scope a block is associated
with.
Document a lot of previously poorly-understood (by me, at least) behavior.
The new framework implements the Horrible Hack (tm), which requires every
landing pad to have a catch-all so that inlining will work. Clang no longer
requires the Horrible Hack just to make exceptions flow correctly within
a function, however. The HH is an unfortunate requirement of LLVM's EH IR.
llvm-svn: 107631
complex values either. Previously we did this properly for regular assignment,
but not for compound assignment.
- Also, tidy up assignment code a bit to look more like the scalar path.
llvm-svn: 107217
would trigger an extra method call).
- While in the area, I also changed Clang to not emit an unnecessary load from
'x' in cases like 'y = (x = 1)'.
llvm-svn: 107210
'self' variable arising from uses of the 'super' keyword. Also reorganize
some code so that BlockInfo (now CGBlockInfo) can be opaque outside of
CGBlocks.cpp.
Fixes rdar://problem/8010633.
llvm-svn: 104312
user directive is needed to force a property implementation.
It is decided based on those propeties which are declared in
the class (or in its protocols) but not those which must be
default implemented by one of its super classes. Implements radar 7923851.
llvm-svn: 103787
- Fix some places that had the alignment hard coded.
- Use ABI type alignment, not preferred type alignment -- neither of this is exactly right, as we really want the C type alignment as required by the runtime, but the ABI alignment is a more correct choice.
This should be equivalent for x86_64, but fixes the alignment for ARM.
llvm-svn: 102314
- Replace -cc1 level -fobjc-legacy-dispatch with -fobjc-dispatch-method={legacy,non-legacy,mixed}.
- Lift "mixed" vs "non-mixed" policy choice up to driver level, instead of being buried in CGObjCMac.cpp.
- No intended functionality change.
llvm-svn: 102255
This mirror's Dan's patch for llvm-gcc in r97989, and
fixes the miscompilation in PR6525. There is some contention
over whether this is the right thing to do, but it is the
conservative answer and demonstrably fixes a miscompilation.
llvm-svn: 101877
a common source of oddities and, in theory, removes some redundant ABI
computations. Also fixes a miscompile I introduced yesterday by refactoring
some code and causing a slightly different code path to be taken that
didn't perform *parameter* type canonicalization, just normal type
canonicalization; this in turn caused a bit of ABI code to misfire because
it was looking for 'double' or 'float' but received 'const float'.
llvm-svn: 97030
(http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20091214/092780.html)
The instruction fixes were checked and approved by Chris Lattner, but
these testcase fixes are mine; please yell at me if there are any
problems with either.
* PR5050-constructor-conversion.cpp
* array-construction.cpp
* constructor-conversion.cpp
* cast-conversion.cpp
* constructor-default-arg.cpp
* derived-to-base-conv.cpp
* ptr-to-member-function.cpp
* call-arg-zero-temp.cpp
* default-destructor-synthesis.cpp
* global-array-destruction.cpp
* array-operator-delete-call.cpp
* decl-ref-init.cpp
* default-constructor-for-members.cpp
* convert-to-fptr.cpp
* constructor-for-array-members.cpp
* conversion-function.cpp
* objc-read-weak-byref.m
Fixed testcase to reflect call qualifier
llvm-svn: 91640
non-existing 'isa' field of a non-existing struct type
all related to legacy type definition for 'id' which we have
dropped in clang in favor of a built-in type.
(fixes radar 7470820).
llvm-svn: 91455
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
of a subclass (direct or indirect) of a weak_import root class, emit a weak reference
for the root class's metaclass (should complete radar 6815425).
llvm-svn: 90249
type and fixes a long-standing code gen. crash reported in
at least two PRs and a radar. (radar 7405040 and pr5025).
There are couple of remaining issues that I would like for
Ted. and Doug to look at:
Ted, please look at failure in Analysis/MissingDealloc.m.
I have temporarily added an expected-warning to make the
test pass. This tests has a declaration of 'SEL' type which
may not co-exist with the new changes.
Doug, please look at a FIXME in PCHWriter.cpp/PCHReader.cpp.
I think the changes which I have ifdef'ed out are correct. They
need be considered for in a few Indexer/PCH test cases.
llvm-svn: 89561
This fixes some bad -O0 codegen and the unnecessary clearing of al on entry to objc_msgSend for most message sends.
<rdar://problem/7102824> [irgen] unnecessary xorb on calls to objc_msgSend on x86_64
llvm-svn: 82118
- Previously this would crash on recursive types, and it was also incorrectly
stripping off a level of indirection.
- I'm not 100% convinced this is all correct, but it should be a monotonic
improvment.
llvm-svn: 75582
The idea is to segregate Objective-C "object" pointers from general C pointers (utilizing the recently added ObjCObjectPointerType). The fun starts in Sema::GetTypeForDeclarator(), where "SomeInterface *" is now represented by a single AST node (rather than a PointerType whose Pointee is an ObjCInterfaceType). Since a significant amount of code assumed ObjC object pointers where based on C pointers/structs, this patch is very tedious. It should also explain why it is hard to accomplish this in smaller, self-contained patches.
This patch does most of the "heavy lifting" related to moving from PointerType->ObjCObjectPointerType. It doesn't include all potential "cleanups". The good news is additional cleanups can be done later (some are noted in the code). This patch is so large that I didn't want to include any changes that are purely aesthetic.
By making the ObjC types truly built-in, they are much easier to work with (and require fewer "hacks"). For example, there is no need for ASTContext::isObjCIdStructType() or ASTContext::isObjCClassStructType()! We believe this change (and the follow-up cleanups) will pay dividends over time.
Given the amount of code change, I do expect some fallout from this change (though it does pass all of the clang tests). If you notice any problems, please let us know asap! Thanks.
llvm-svn: 75314
variables in ObjC's Next runtime mode. Next runtime also implicitly applies
'used' attribute on some of its meta-data. This results in two
'llvm.used' arrays to be generated, and one of them is renamed to
'llvm.used1'.
llvm-svn: 74008
___Block_byref_id_object_dispose and ___Block_byref_id_object_copy
functions so that we can simply reuse instead of creating a new one.
Additionally, add an assert to ensure no one yet tries to align a
__block variable beyond the alignment of a pointer as the codegen is
incomplete.
llvm-svn: 72974
- Otherwise we emit internal names with embedded '\01' characters,
which confuses some tools.
- Ideally all the code which wants to get a "display name" for the
given function should follow one code path, but this should be a
monotonic improvement for now.
llvm-svn: 71774
message dispage API for all but a few messages. This is
a runtime performance improvement and there is not meant
to be a functional change.
llvm-svn: 71467
compensating for super classes). This was making the reported class
sizes for empty classes very, very wrong.
- Also, we now report the size info for an empty class like gcc (as
the offset of the start, not as 0, 0).
- Add a few more test cases we were mishandling before (padding bit
field at end of struct, for example).
llvm-svn: 70938
via CollectObjCIvars.
- In places where we need them, we should have the implementation and
access the properties through it.
This is a fairly substantial functionality change:
1. @encode no longer encodes synthesized ivars, ever.
2. The ivar layout bitmap no longer encodes information for
synthesized ivars in superclasses. Well, actually I had already
broken that, but it is intentional now.
We are now differing substantially from llvm-gcc and gcc
here. However, in my opinion this fundamentally *must* work if
non-fragile classes are to work. Without this change, the result of
@encode and the ivar layout depend on the order that the
implementation is seen in a file (if it is in the same file with its
superclass). Since both scenarios should work the same, our behavior
is now consistent with gcc behavior as if an implementation is never
seen following an implementation of its superclass.
Note that #2 is only a functionality change when (A) an
implementation appears in the same translation unit with the
implementation of its superclass, and (B) the superclass has
synthesized ivars. My belief is that this situation does not occur in
practice.
I am not yet sure of the role/semantics of @encode when synthesized
ivars are present... it's use is fairly unsound in a non-fragile world.
llvm-svn: 70822
Pete Cooper