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
Related result types apply Cocoa conventions to the type of message
sends and property accesses to Objective-C methods that are known to
always return objects whose type is the same as the type of the
receiving class (or a subclass thereof), such as +alloc and
-init. This tightens up static type safety for Objective-C, so that we
now diagnose mistakes like this:
t.m:4:10: warning: incompatible pointer types initializing 'NSSet *'
with an
expression of type 'NSArray *' [-Wincompatible-pointer-types]
NSSet *array = [[NSArray alloc] init];
^ ~~~~~~~~~~~~~~~~~~~~~~
/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:72:1:
note:
instance method 'init' is assumed to return an instance of its
receiver
type ('NSArray *')
- (id)init;
^
It also means that we get decent type inference when writing code in
Objective-C++0x:
auto array = [[NSMutableArray alloc] initWithObjects:@"one", @"two",nil];
// ^ now infers NSMutableArray* rather than id
llvm-svn: 132868
There are APIs, e.g. [NSValue valueWithBytes:objCType:], which use the encoding to find out
the size of an object pointed to by a pointer. Make things safer by making it illegal to @encode
incomplete types.
llvm-svn: 131364
bit by allowing __weak and __strong to be added/dropped as part of
implicit conversions (qualification conversions in C++). A little
history: GCC lets one add/remove/change GC qualifiers just about
anywhere, implicitly. Clang did roughly the same before, but we
recently normalized the semantics of qualifiers across the board to
get a semantics that we could reason about (yay). Unfortunately, this
tightened the screws a bit too much for GC qualifiers, where it's
common to add/remove these qualifiers at will.
Overall, we're still in better shape than we were before: we don't
permit directly changing the GC qualifier (e.g., __weak -> __strong),
so type safety is improved. More importantly, we're internally
consistent in our handling of qualifiers, and the logic that allows
adding/removing GC qualifiers (but not adding/removing address
spaces!) only touches two obvious places.
Fixes <rdar://problem/9402499>.
llvm-svn: 131065
invalid expression rather than the far-more-generic "error". Fixes a
mild regression in error recovery uncovered by the GCC testsuite.
llvm-svn: 130128
-Wwrite-strings. First and foremost, once the positive form of the flag
was passed, it could never be disabled by passing -Wno-write-strings.
Also, the diagnostic engine couldn't in turn use -Wwrite-strings to
control diagnostics (as GCC does) because it was essentially hijacked to
drive the language semantics.
Fix this by giving CC1 a clean '-fconst-strings' flag to enable
const-qualified strings in C and ObjC compilations. Corresponding
'-fno-const-strings' is also added. Then the driver is taught to
introduce '-fconst-strings' in the CC1 command when '-Wwrite-strings'
dominates.
This entire flag is basically GCC-bug-compatibility driven, so we also
match GCC's bug where '-w' doesn't actually disable -Wwrite-strings. I'm
open to changing this though as it seems insane.
llvm-svn: 130051
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
definitely have a path leading to them, and possibly have a path leading
to them; reflect that distinction in the warning text emitted.
llvm-svn: 129126
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
declaration as this results in a confusing error message,
instead of message related to missing property declaration.
// rdar://9106929
llvm-svn: 127682
diagnostic. Also, these attributes are commonly written with macros which we
actually pre-define, so instead of expanding the macro location, refer to the
instantiation location and name it using the macro loc.
llvm-svn: 127219
Fariborz Jahanian