Add -Wpartial-availability.

This warns when using decls that are not available on all deployment targets.
For example, a call to

  - (void)ppartialMethod __attribute__((availability(macosx,introduced=10.8)));

will warn if -mmacosx-version-min is set to less than 10.8.

To silence the warning, one has to explicitly redeclare the method like so:

  @interface Whatever(MountainLionAPI)
  - (void)ppartialMethod;
  @end

This way, one cannot accidentally call a function that isn't available
everywhere.  Having to add the redeclaration will hopefully remind the user
to add an explicit respondsToSelector: call as well.

Some projects build against old SDKs to get this effect, but building against
old SDKs suppresses some bug fixes -- see http://crbug.com/463171 for examples.
The hope is that SDK headers are annotated well enough with availability
attributes that new SDK + this warning offers the same amount of protection
as using an old SDK.

llvm-svn: 232750

1 files changed, 25 insertions, 0 deletions

diff --git a/clang/test/Sema/attr-availability.c b/clang/test/Sema/attr-availability.c
index b7a8e6ef0f5..48bdf26598c 100644
--- a/clang/test/Sema/attr-availability.c
+++ b/clang/test/Sema/attr-availability.c
@@ -1,4 +1,6 @@
 // RUN: %clang_cc1 -triple x86_64-apple-darwin9 -fsyntax-only -fblocks -verify %s
+// RUN: %clang_cc1 -D WARN_PARTIAL -Wpartial-availability -triple x86_64-apple-darwin9 -fsyntax-only -fblocks -verify %s
+// 
 
 void f0() __attribute__((availability(macosx,introduced=10.4,deprecated=10.2))); // expected-warning{{feature cannot be deprecated in OS X version 10.2 before it was introduced in version 10.4; attribute ignored}}
 void f1() __attribute__((availability(ios,obsoleted=2.1,deprecated=3.0)));  // expected-warning{{feature cannot be obsoleted in iOS version 2.1 before it was deprecated in version 3.0; attribute ignored}}
@@ -13,9 +15,32 @@ ATSFontGetName(const char *oName) __attribute__((availability(macosx,introduced=
 extern void
 ATSFontGetPostScriptName(int flags) __attribute__((availability(macosx,introduced=8.0,obsoleted=9.0, message="use ATSFontGetFullPostScriptName"))); // expected-note {{'ATSFontGetPostScriptName' has been explicitly marked unavailable here}}
 
+#if defined(WARN_PARTIAL)
+// expected-note@+3 {{has been explicitly marked partial here}}
+#endif
+extern void
+PartiallyAvailable() __attribute__((availability(macosx,introduced=10.8)));
+
+enum __attribute__((availability(macosx,introduced=10.8))) PartialEnum {
+  kPartialEnumConstant,
+};
+
 void test_10095131() {
   ATSFontGetName("Hello"); // expected-warning {{'ATSFontGetName' is deprecated: first deprecated in OS X 9.0 - use CTFontCopyFullName}}
   ATSFontGetPostScriptName(100); // expected-error {{'ATSFontGetPostScriptName' is unavailable: obsoleted in OS X 9.0 - use ATSFontGetFullPostScriptName}}
+
+#if defined(WARN_PARTIAL)
+  // expected-warning@+2 {{is partial: introduced in OS X 10.8}} expected-note@+2 {{explicitly redeclare 'PartiallyAvailable' to silence this warning}}
+#endif
+  PartiallyAvailable();
+}
+
+extern void PartiallyAvailable() ;
+void with_redeclaration() {
+  PartiallyAvailable();  // Don't warn.
+
+  // enums should never warn.
+  enum PartialEnum p = kPartialEnumConstant;
 }
 
 // rdar://10711037