idiom that is used commonly in setters:
[backingValue autorelease];
backingValue = [newValue retain]; // in general a +1 assign
rdar://9914061
llvm-svn: 157347
migration error.
This is more trouble that it is worth; autoreleasing a value without holding on it
is a valid use-case, we should not "punish" correct code for the minority of
broken/fragile programs that depend on the behavior of -autorelease.
rdar://9914061
llvm-svn: 156999
the new Objective-C NSArray/NSDictionary/NSNumber literal syntax.
This introduces a new library, libEdit, which provides a new way to support
migration of code that improves on the original ARC migrator. We now believe
that most of its functionality can be refactored into the existing libraries,
and thus this new library may shortly disappear.
llvm-svn: 152141
property references to use a new PseudoObjectExpr
expression which pairs a syntactic form of the expression
with a set of semantic expressions implementing it.
This should significantly reduce the complexity required
elsewhere in the compiler to deal with these kinds of
expressions (e.g. IR generation's special l-value kind,
the static analyzer's Message abstraction), at the lower
cost of specifically dealing with the odd AST structure
of these expressions. It should also greatly simplify
efforts to implement similar language features in the
future, most notably Managed C++'s properties and indexed
properties.
Most of the effort here is in dealing with the various
clients of the AST. I've gone ahead and simplified the
ObjC rewriter's use of properties; other clients, like
IR-gen and the static analyzer, have all the old
complexity *and* all the new complexity, at least
temporarily. Many thanks to Ted for writing and advising
on the necessary changes to the static analyzer.
I've xfailed a small diagnostics regression in the static
analyzer at Ted's request.
llvm-svn: 143867
- Replace calling -zone with 'nil'. -zone is obsolete in ARC.
- Allow removing retain/release on a static global var.
- Fix assertion hit when scanning for name references outside a NSAutoreleasePool scope.
- Automatically add bridged casts for results of objc method calls and when calling CFRetain, for example:
NSString *s;
CFStringRef ref = [s string]; -> CFStringRef ref = (__bridge CFStringRef)([s string]);
ref = s.string; -> ref = (__bridge CFStringRef)(s.string);
ref = [NSString new]; -> ref = (__bridge_retained CFStringRef)([NSString new]);
ref = [s newString]; -> ref = (__bridge_retained CFStringRef)([s newString]);
ref = [[NSString alloc] init]; -> ref = (__bridge_retained CFStringRef)([[NSString alloc] init]);
ref = [[s string] retain]; -> ref = (__bridge_retained CFStringRef)([s string]);
ref = CFRetain(s); -> ref = (__bridge_retained CFTypeRef)(s);
ref = [s retain]; -> ref = (__bridge_retained CFStringRef)(s);
- Emit migrator error when trying to cast to CF type the result of autorelease/release:
for
CFStringRef f3() {
return (CFStringRef)[[[NSString alloc] init] autorelease];
}
emits:
t.m:12:10: error: [rewriter] it is not safe to cast to 'CFStringRef' the result of 'autorelease' message; a __bridge cast may result in a pointer to a destroyed object and a __bridge_retained may leak the object
return (CFStringRef)[[[NSString alloc] init] autorelease];
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
t.m:12:3: note: [rewriter] remove the cast and change return type of function to 'NSString *' to have the object automatically autoreleased
return (CFStringRef)[[[NSString alloc] init] autorelease];
^
- Before changing attributes to weak/unsafe_unretained, check if the backing ivar
is set to a +1 object, in which case use 'strong' instead.
llvm-svn: 136208
that, after migration, the object that was passed to 'setDelegate:' will not be properly retained, e.g:
-whatever {
id x = [[MyDoHicky alloc] init];
[someivar setDelegate: x]; // x won't get retained in ARC.
}
-dealloc {
[[someivar delegate] release]; // give migration error here.
}
rdar://8858009
llvm-svn: 135327
id x = ...
@try {
...
} @finally {
[x release];
}
Migrator will drop the release. It's better to change it to "x = 0" in a @finally to avoid leak when exception is thrown.
rdar://9398256
llvm-svn: 135301
An unused autorelease is badness. If we remove it the receiver
will likely die immediately while previously it was kept alive
by the autorelease pool. This is bad practice in general, so leave it
and emit an error to force the user to restructure his code.
rdar://9599884
llvm-svn: 135193
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
Benjamin Kramer