Add 'nopartial' qualifier for availability attributes.

An optional nopartial can be placed after the platform name.
int bar() __attribute__((availability(macosx,nopartial,introduced=10.12))

When deploying back to a platform version prior to when the declaration was
introduced, with 'nopartial', Clang emits an error specifying that the function
is not introduced yet; without 'nopartial', the behavior stays the same: the
declaration is `weakly linked`.

A member is added to the end of AttributeList to save the location of the
'nopartial' keyword. A bool member is added to AvailabilityAttr.

The diagnostics for 'nopartial' not-yet-introduced is handled in the same way as
we handle unavailable cases.

Reviewed by Doug Gregor and Jordan Rose.

rdar://23791325

llvm-svn: 261163

1 files changed, 30 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 9351c52afbc..bfb82ac1388 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -1916,6 +1916,7 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(NamedDecl *D, SourceRange Range,
                                               VersionTuple Obsoleted,
                                               bool IsUnavailable,
                                               StringRef Message,
+                                              bool IsNopartial,
                                               AvailabilityMergeKind AMK,
                                               unsigned AttrSpellingListIndex) {
   VersionTuple MergedIntroduced = Introduced;
@@ -2062,7 +2063,7 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(NamedDecl *D, SourceRange Range,
     return ::new (Context) AvailabilityAttr(Range, Context, Platform,
                                             Introduced, Deprecated,
                                             Obsoleted, IsUnavailable, Message,
-                                            AttrSpellingListIndex);
+                                            IsNopartial, AttrSpellingListIndex);
   }
   return nullptr;
 }
@@ -2089,6 +2090,7 @@ static void handleAvailabilityAttr(Sema &S, Decl *D,
   AvailabilityChange Deprecated = Attr.getAvailabilityDeprecated();
   AvailabilityChange Obsoleted = Attr.getAvailabilityObsoleted();
   bool IsUnavailable = Attr.getUnavailableLoc().isValid();
+  bool IsNopartial = Attr.getNopartialLoc().isValid();
   StringRef Str;
   if (const StringLiteral *SE =
           dyn_cast_or_null<StringLiteral>(Attr.getMessageExpr()))
@@ -2099,6 +2101,7 @@ static void handleAvailabilityAttr(Sema &S, Decl *D,
                                                       Deprecated.Version,
                                                       Obsoleted.Version,
                                                       IsUnavailable, Str,
+                                                      IsNopartial,
                                                       Sema::AMK_None,
                                                       Index);
   if (NewAttr)
@@ -2143,6 +2146,7 @@ static void handleAvailabilityAttr(Sema &S, Decl *D,
                                                             NewDeprecated,
                                                             NewObsoleted,
                                                             IsUnavailable, Str,
+                                                            IsNopartial,
                                                             Sema::AMK_None,
                                                             Index);
         if (NewAttr)
@@ -2165,6 +2169,7 @@ static void handleAvailabilityAttr(Sema &S, Decl *D,
                                                             Deprecated.Version,
                                                             Obsoleted.Version,
                                                             IsUnavailable, Str,
+                                                            IsNopartial,
                                                             Sema::AMK_None,
                                                             Index);
         if (NewAttr)
@@ -5957,6 +5962,14 @@ static void DoEmitAvailabilityWarning(Sema &S, Sema::AvailabilityDiagnostic K,
     property_note_select = /* partial */ 2;
     available_here_select_kind = /* partial */ 3;
     break;
+
+  case Sema::AD_NotYetIntroduced:
+    diag = diag::err_notyetintroduced;
+    diag_message = diag::err_notyetintroduced_message;
+    diag_fwdclass_message = diag::warn_notyetintroduced_fwdclass_message;
+    property_note_select = /* deprecated */ 3;
+    available_here_select_kind = /* notyetintroduced */ 4;
+    break;
   }
 
   if (!Message.empty()) {
@@ -5983,10 +5996,22 @@ static void DoEmitAvailabilityWarning(Sema &S, Sema::AvailabilityDiagnostic K,
 static void handleDelayedAvailabilityCheck(Sema &S, DelayedDiagnostic &DD,
                                            Decl *Ctx) {
   assert(DD.Kind == DelayedDiagnostic::Deprecation ||
-         DD.Kind == DelayedDiagnostic::Unavailable);
-  Sema::AvailabilityDiagnostic AD = DD.Kind == DelayedDiagnostic::Deprecation
-                                        ? Sema::AD_Deprecation
-                                        : Sema::AD_Unavailable;
+         DD.Kind == DelayedDiagnostic::Unavailable ||
+         DD.Kind == DelayedDiagnostic::NotYetIntroduced);
+  Sema::AvailabilityDiagnostic AD;
+  switch (DD.Kind) {
+  case DelayedDiagnostic::Deprecation:
+    AD = Sema::AD_Deprecation;
+    break;
+  case DelayedDiagnostic::Unavailable:
+    AD = Sema::AD_Unavailable;
+    break;
+  case DelayedDiagnostic::NotYetIntroduced:
+    AD = Sema::AD_NotYetIntroduced;
+    break;
+  default:
+    llvm_unreachable("Expecting: deprecated, unavailable, not-yet-introduced");
+  }
   DD.Triggered = true;
   DoEmitAvailabilityWarning(
       S, AD, Ctx, DD.getDeprecationDecl(), DD.getDeprecationMessage(), DD.Loc,