objective-c: warn when autosynthesizing a property which has same

name as an existing ivar since this is common source of error
when people remove @synthesize to take advantage of autosynthesis.
// rdar://11671080

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158756 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 9ca078d1bd91477f2aaf35b4fc17ed7d074267b7..d27acf7b9966609dd2a7a20b3fef566cd815c44b 100644 (file)
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -630,6 +630,9 @@ def warn_auto_synthesizing_protocol_property :Warning<
   "auto property synthesis will not synthesize property"
   " declared in a protocol">,
   InGroup<DiagGroup<"objc-protocol-property-synthesis">>;
+def warn_autosynthesis_property_ivar_match :Warning<
+  "auto autosynthesized property has same name as an existing ivar">,
+  InGroup<DiagGroup<"objc-autosynthesis-property-ivar-name-match">>;
 def warn_missing_explicit_synthesis : Warning <
   "auto property synthesis is synthesizing property not explicitly synthesized">,
   InGroup<DiagGroup<"objc-missing-property-synthesis">>, DefaultIgnore;

diff --git a/lib/Sema/SemaObjCProperty.cpp b/lib/Sema/SemaObjCProperty.cpp
index 84dc9cae233fc39cf1f6c197931bc2de7823bc80..20dbf58c9869c96a9443ec604b35e99b7049ffc9 100644 (file)
--- a/lib/Sema/SemaObjCProperty.cpp
+++ b/lib/Sema/SemaObjCProperty.cpp
@@ -755,6 +755,22 @@ Decl *Sema::ActOnPropertyImplDecl(Scope *S,
     }
 
     if (!Ivar) {
+      if (AtLoc.isInvalid()) {
+        // Check when default synthesizing a property that there is 
+        // an ivar matching property name and issue warning; since this
+        // is the most common case of not using an ivar used for backing
+        // property in non-default synthesis case.
+        ObjCInterfaceDecl *ClassDeclared=0;
+        ObjCIvarDecl *originalIvar = 
+          IDecl->lookupInstanceVariable(property->getIdentifier(), 
+                                        ClassDeclared);
+        if (originalIvar) {
+          Diag(PropertyDiagLoc, 
+               diag::warn_autosynthesis_property_ivar_match);
+          Diag(property->getLocation(), diag::note_property_declare);
+          Diag(originalIvar->getLocation(), diag::note_ivar_decl);
+        }
+      }
       // In ARC, give the ivar a lifetime qualifier based on the
       // property attributes.
       if (getLangOpts().ObjCAutoRefCount &&

diff --git a/test/SemaObjC/default-synthesize-2.m b/test/SemaObjC/default-synthesize-2.m
index b95f263c32d2f0a95a1af1a190619b137a4bed6e..eeeab5f5c469edb3ddd099a53788a9c89871deda 100644 (file)
--- a/test/SemaObjC/default-synthesize-2.m
+++ b/test/SemaObjC/default-synthesize-2.m
@@ -41,12 +41,13 @@
 // Test3
 @interface Test3 
 { 
-  id uid; 
+  id uid;  // expected-note {{ivar is declared here}}
 } 
-@property (readwrite, assign) id uid; 
+@property (readwrite, assign) id uid;  // expected-note {{property declared here}}
 @end
 
-@implementation Test3
+// rdar://11671080
+@implementation Test3 // expected-warning {{auto autosynthesized property has same name as an existing ivar}}
 // Oops, forgot to write @synthesize! will be default synthesized
 - (void) myMethod { 
    self.uid = 0; // Use of the “setter”