forked from OSchip/llvm-project
20b2ebd785
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
|
||
|---|---|---|
| .. | ||
| AnalysisBasedWarnings.cpp | ||
| AttributeList.cpp | ||
| CMakeLists.txt | ||
| CodeCompleteConsumer.cpp | ||
| DeclSpec.cpp | ||
| IdentifierResolver.cpp | ||
| JumpDiagnostics.cpp | ||
| Makefile | ||
| Sema.cpp | ||
| SemaAccess.cpp | ||
| SemaAttr.cpp | ||
| SemaCXXCast.cpp | ||
| SemaCXXScopeSpec.cpp | ||
| SemaChecking.cpp | ||
| SemaCodeComplete.cpp | ||
| SemaDecl.cpp | ||
| SemaDeclAttr.cpp | ||
| SemaDeclCXX.cpp | ||
| SemaDeclObjC.cpp | ||
| SemaExceptionSpec.cpp | ||
| SemaExpr.cpp | ||
| SemaExprCXX.cpp | ||
| SemaExprObjC.cpp | ||
| SemaInit.cpp | ||
| SemaLookup.cpp | ||
| SemaObjCProperty.cpp | ||
| SemaOverload.cpp | ||
| SemaStmt.cpp | ||
| SemaTemplate.cpp | ||
| SemaTemplateDeduction.cpp | ||
| SemaTemplateInstantiate.cpp | ||
| SemaTemplateInstantiateDecl.cpp | ||
| SemaTemplateVariadic.cpp | ||
| SemaType.cpp | ||
| TargetAttributesSema.cpp | ||
| TargetAttributesSema.h | ||
| TreeTransform.h | ||
| TypeLocBuilder.h | ||