StartFunction enters a release cleanup for ns_consumed arguments in
ARC, so we need to balance that somehow. We could teach StartFunction
that it's emitting a delegating function, so that the cleanup is
unnecessary, but that would be invasive and somewhat fraught. We could
balance the consumed argument with an extra retain, but clearing the
original variable should be easier to optimize and avoid some extra work
at -O0. And there shouldn't be any difference as long as nothing else
uses the argument, which should always be true for the places we emit
delegate arguments.
Fixes PR 27887.
llvm-svn: 287291
When a function/method use a parameter with "ns_consumed" attribute,
ensure that the mangled name is the same whether -fobjc-arc is used
or not.
Since "ns_consumed" attribute is generally used to inform ARC that
a function/method does sink the reference, it mean it is usually
implemented in a compilation unit compiled without -fobjc-arc but
used form a compilation unit compiled with it.
Originally found while trying to use "ns_consumed" attribute in an
Objective-C++ file in Chromium (http://crbug.com/599980) where it
caused a linker error.
Regression introduced by revision 262278 (previously the attribute
was incorrectly not part of the mangled name).
Patch from Sylvain Defresne <sdefresne@chromium.org>!
http://reviews.llvm.org/D20113
llvm-svn: 270702
ARC ownership-convention function type modifications.
According to the Itanium ABI, vendor extended qualifiers are
supposed to be mangled in reverse-alphabetical order before
any CVR qualifiers. The ARC function type conventions are
plausibly order-significant (they are associated with the
function type), which permits us to ignore the need to correctly
inter-order them with any other vendor qualifiers on the parameter
and return types.
Implementing these rules correctly is technically an ABI break.
Apple is comfortable with the risk of incompatibility here for
the ARC features, and I believe that address-space qualification
is still uncommon enough to allow us to adopt the conforming
rule without serious risk. Still, targets which make heavy
use of address space qualification may want to revert to the
non-conforming order.
llvm-svn: 262414
This was causing correctness issues for ARC and the static analyzer when a
function template has "consumed" Objective-C object parameters (i.e.
parameters that will be released by the function before returning).
The fix is threefold:
(1) Actually copy over the attributes from old ParmVarDecls to new ones.
(2) Have Sema::BuildFunctionType only work for building FunctionProtoTypes,
which it was doing anyway. This allows us to pass an ExtProtoInfo
instead of a plain ExtInfo and several flags.
(3) Drop param attributes as part of StripImplicitInstantiation, which is
used when an implicit instantiation is followed by an explicit one.
<rdar://problem/12685622>
llvm-svn: 176728
John McCall