Availability: attach the note to the declaration with the attributes.

Sometimes, the declaration we found has inherited availability
attributes, attaching the note to it does not tell us where the
availability attributes are in the source.

Go through the redecl chain to find the declaration with actual
availability attributes.

rdar://25221771

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@268786 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index cbc95dc643dd3ca94f1e84535fd753538c0a3b22..e0272a0eb63695afa5da92224f81e4f55cc70816 100644 (file)
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -6171,6 +6171,34 @@ static bool isDeclUnavailable(Decl *D) {
   return false;
 }
 
+static const AvailabilityAttr *getAttrForPlatform(ASTContext &Context,
+                                                  const Decl *D) {
+  // Check each AvailabilityAttr to find the one for this platform.
+  for (const auto *A : D->attrs()) {
+    if (const auto *Avail = dyn_cast<AvailabilityAttr>(A)) {
+      // FIXME: this is copied from CheckAvailability. We should try to
+      // de-duplicate.
+
+      // Check if this is an App Extension "platform", and if so chop off
+      // the suffix for matching with the actual platform.
+      StringRef ActualPlatform = Avail->getPlatform()->getName();
+      StringRef RealizedPlatform = ActualPlatform;
+      if (Context.getLangOpts().AppExt) {
+        size_t suffix = RealizedPlatform.rfind("_app_extension");
+        if (suffix != StringRef::npos)
+          RealizedPlatform = RealizedPlatform.slice(0, suffix);
+      }
+
+      StringRef TargetPlatform = Context.getTargetInfo().getPlatformName();
+
+      // Match the platform name.
+      if (RealizedPlatform == TargetPlatform)
+        return Avail;
+    }
+  }
+  return nullptr;
+}
+
 static void DoEmitAvailabilityWarning(Sema &S, Sema::AvailabilityDiagnostic K,
                                       Decl *Ctx, const NamedDecl *D,
                                       StringRef Message, SourceLocation Loc,
@@ -6268,7 +6296,7 @@ static void DoEmitAvailabilityWarning(Sema &S, Sema::AvailabilityDiagnostic K,
   if (K == Sema::AD_Deprecation) {
     if (auto attr = D->getAttr<DeprecatedAttr>())
       Replacement = attr->getReplacement();
-    if (auto attr = D->getAttr<AvailabilityAttr>())
+    if (auto attr = getAttrForPlatform(S.Context, D))
       Replacement = attr->getReplacement();
 
     if (!Replacement.empty())
@@ -6297,8 +6325,27 @@ static void DoEmitAvailabilityWarning(Sema &S, Sema::AvailabilityDiagnostic K,
     S.Diag(UnknownObjCClass->getLocation(), diag::note_forward_class);
   }
 
-  S.Diag(D->getLocation(), diag_available_here)
-      << D << available_here_select_kind;
+  // The declaration can have multiple availability attributes, we are looking
+  // at one of them.
+  const AvailabilityAttr *A = getAttrForPlatform(S.Context, D);
+  if (A && A->isInherited()) {
+    for (const Decl *Redecl = D->getMostRecentDecl(); Redecl;
+         Redecl = Redecl->getPreviousDecl()) {
+      const AvailabilityAttr *AForRedecl = getAttrForPlatform(S.Context,
+                                                              Redecl);
+      if (AForRedecl && !AForRedecl->isInherited()) {
+        // If D is a declaration with inherited attributes, the note should
+        // point to the declaration with actual attributes.
+        S.Diag(Redecl->getLocation(), diag_available_here) << D
+            << available_here_select_kind;
+        break;
+      }
+    }
+  }
+  else
+    S.Diag(D->getLocation(), diag_available_here)
+        << D << available_here_select_kind;
+
   if (K == Sema::AD_Partial)
     S.Diag(Loc, diag::note_partial_availability_silence) << D;
 }

diff --git a/test/Sema/attr-availability-macosx.c b/test/Sema/attr-availability-macosx.c
index 21a79ff17a15f928b5639c2d257ecf8bc07320a6..6991f14d9500d06a46c50c89ae24839b4eb8ecfc 100644 (file)
--- a/test/Sema/attr-availability-macosx.c
+++ b/test/Sema/attr-availability-macosx.c
@@ -45,3 +45,14 @@ enum {
 enum __attribute__((availability(macosx,introduced=8.0,deprecated=9.0))) {
     bar1 = foo
 };
+
+// Make sure the note is on the declaration with the actual availability attributes.
+struct __attribute__((availability(macosx,strict,introduced=10.9))) type_info // \
+    expected-note{{'type_info' has been explicitly marked unavailable here}}
+{
+};
+struct type_info;
+int test2() {
+  struct type_info *t; // expected-error{{'type_info' is unavailable: introduced in OS X 10.9}}
+  return 0;
+}