Disable caching of visibility.

The testcase in pr14929 shows that this is extremely hard to do. If we choose
to apply the attribute, that causes the visibility of some decls to change and
that can happen really late (during codegen).

Current gcc warns and ignores the attribute in this testcase with a warning.
This suggest that the correct solution is to find a point in the compilation
where we can compute the visibility and
* assert it was never computed before
* reject any attempts to compute it again in the future (with warnings).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172305 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 15 deletions

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 225ee24d0f..9c17d6eabd 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -2043,7 +2043,6 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(NamedDecl *D, SourceRange Range,
   VersionTuple MergedDeprecated = Deprecated;
   VersionTuple MergedObsoleted = Obsoleted;
   bool FoundAny = false;
-  bool DroppedAny = false;
 
   if (D->hasAttrs()) {
     AttrVec &Attrs = D->getAttrs();
@@ -2078,7 +2077,6 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(NamedDecl *D, SourceRange Range,
         Diag(OldAA->getLocation(), diag::warn_mismatched_availability);
         Diag(Range.getBegin(), diag::note_previous_attribute);
         Attrs.erase(Attrs.begin() + i);
-        DroppedAny = true;
         --e;
         continue;
       }
@@ -2098,7 +2096,6 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(NamedDecl *D, SourceRange Range,
                                 MergedIntroduced2, MergedDeprecated2,
                                 MergedObsoleted2)) {
         Attrs.erase(Attrs.begin() + i);
-        DroppedAny = true;
         --e;
         continue;
       }
@@ -2110,9 +2107,6 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(NamedDecl *D, SourceRange Range,
     }
   }
 
-  if (DroppedAny)
-    D->ClearLVCache();
-
   if (FoundAny &&
       MergedIntroduced == Introduced &&
       MergedDeprecated == Deprecated &&
@@ -2159,10 +2153,8 @@ static void handleAvailabilityAttr(Sema &S, Decl *D,
                                                       Deprecated.Version,
                                                       Obsoleted.Version,
                                                       IsUnavailable, Str);
-  if (NewAttr) {
+  if (NewAttr)
     D->addAttr(NewAttr);
-    ND->ClearLVCache();
-  }
 }
 
 VisibilityAttr *Sema::mergeVisibilityAttr(Decl *D, SourceRange Range,
@@ -2179,8 +2171,6 @@ VisibilityAttr *Sema::mergeVisibilityAttr(Decl *D, SourceRange Range,
     Diag(ExistingAttr->getLocation(), diag::err_mismatched_visibility);
     Diag(Range.getBegin(), diag::note_previous_attribute);
     D->dropAttr<VisibilityAttr>();
-    NamedDecl *ND = cast<NamedDecl>(D);
-    ND->ClearLVCache();
   }
   return ::new (Context) VisibilityAttr(Range, Context, Vis);
 }
@@ -2224,11 +2214,8 @@ static void handleVisibilityAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   }
 
   VisibilityAttr *NewAttr = S.mergeVisibilityAttr(D, Attr.getRange(), type);
-  if (NewAttr) {
+  if (NewAttr)
     D->addAttr(NewAttr);
-    NamedDecl *ND = cast<NamedDecl>(D);
-    ND->ClearLVCache();
-  }
 }
 
 static void handleObjCMethodFamilyAttr(Sema &S, Decl *decl,