commit 4e7f00c74487bca84993a1f35d0a26a84ed2b1a0
author Fariborz Jahanian <fjahanian@apple.com> Fri Oct 25 21:44:50 2013 +0000
committer Fariborz Jahanian <fjahanian@apple.com> Fri Oct 25 21:44:50 2013 +0000
tree 2d00120c4b90c7f1a4b200eac58999059b1a6d97
parent 73e9431d545cdbb8b61d1c9e7930832162e6011f

ObjectiveC: under -Wunused-property-ivar warn if property's
backing warning is not used in one of its accessor methods.
// rdar://14989999


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193439 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaDecl.cpp

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 2edebab..35bb3a3 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1388,6 +1388,7 @@
     // Remove this name from our lexical scope.
     IdResolver.RemoveDecl(D);
   }
+  DiagnoseUnusedBackingIvarInAccessor(S);
 }
 
 void Sema::ActOnStartFunctionDeclarator() {

lib/Sema/SemaDeclObjC.cpp

diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index d256658..be78767 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -3501,3 +3501,34 @@
   }
   return;
 }
+
+ObjCIvarDecl *
+Sema::GetIvarBackingPropertyAccessor(const ObjCMethodDecl *Method,
+                                     const ObjCPropertyDecl *&PDecl) const {
+  
+  const ObjCInterfaceDecl *IDecl = Method->getClassInterface();
+  if (!IDecl)
+    return 0;
+  Method = IDecl->lookupMethod(Method->getSelector(), true);
+  if (!Method || !Method->isPropertyAccessor())
+    return 0;
+  if ((PDecl = Method->findPropertyDecl()))
+    return PDecl->getPropertyIvarDecl();
+  return 0;
+}
+
+void Sema::DiagnoseUnusedBackingIvarInAccessor(Scope *S) {
+  if (S->hasUnrecoverableErrorOccurred() || !S->isInObjcMethodScope())
+    return;
+  
+  const ObjCMethodDecl *CurMethod = getCurMethodDecl();
+  if (!CurMethod)
+    return;
+  const ObjCPropertyDecl *PDecl;
+  const ObjCIvarDecl *IV = GetIvarBackingPropertyAccessor(CurMethod, PDecl);
+  if (IV && !IV->getBackingIvarReferencedInAccessor()) {
+    Diag(getCurMethodDecl()->getLocation(), diag::warn_unused_property_backing_ivar)
+    << IV->getDeclName();
+    Diag(PDecl->getLocation(), diag::note_property_declare);
+  }
+}

lib/Sema/SemaExpr.cpp

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 139bf5b..2fca0cd 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -2257,6 +2257,12 @@
         return ExprError();
 
       MarkAnyDeclReferenced(Loc, IV, true);
+      // Mark this ivar 'referenced' in this method, if it is a backing ivar
+      // of a property and current method is one of its property accessor.
+      const ObjCPropertyDecl *PDecl;
+      const ObjCIvarDecl *BIV = GetIvarBackingPropertyAccessor(CurMethod, PDecl);
+      if (BIV && BIV == IV)
+        IV->setBackingIvarReferencedInAccessor(true);
       
       ObjCMethodFamily MF = CurMethod->getMethodFamily();
       if (MF != OMF_init && MF != OMF_dealloc && MF != OMF_finalize &&