Emit a warning for @Property(assign) and @Property(unsafe_unretained) under ARC.

Author: rniwa

clang/lib/StaticAnalyzer/Checkers/WebKit/RawPtrRefMemberChecker.cpp

@@ -38,7 +38,7 @@ class RawPtrRefMemberChecker
   RawPtrRefMemberChecker(const char *description)
       : Bug(this, description, "WebKit coding guidelines") {}
 
-  virtual std::optional<bool> isUnsafePtr(QualType) const = 0;
+  virtual std::optional<bool> isUnsafePtr(QualType, bool ignoreARC = false) const = 0;
   virtual const char *typeName() const = 0;
   virtual const char *invariant() const = 0;
 
@@ -175,11 +175,13 @@ class RawPtrRefMemberChecker
       return;
 
     if (const ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CD)) {
-      if (!RTC || !RTC->defaultSynthProperties() || ID->isObjCRequiresPropertyDefs())
+      if (!RTC || !RTC->defaultSynthProperties() ||
+          ID->isObjCRequiresPropertyDefs())
         return;
     }
 
-    auto IsUnsafePtr = isUnsafePtr(QT);
+    bool ignoreARC = !PD->isReadOnly() && PD->getSetterKind() == ObjCPropertyDecl::Assign;
+    auto IsUnsafePtr = isUnsafePtr(QT, ignoreARC);
     if (!IsUnsafePtr || !*IsUnsafePtr)
       return;
 
@@ -279,7 +281,7 @@ class NoUncountedMemberChecker final : public RawPtrRefMemberChecker {
       : RawPtrRefMemberChecker("Member variable is a raw-pointer/reference to "
                                "reference-countable type") {}
 
-  std::optional<bool> isUnsafePtr(QualType QT) const final {
+  std::optional<bool> isUnsafePtr(QualType QT, bool) const final {
     return isUncountedPtr(QT.getCanonicalType());
   }
 
@@ -296,7 +298,7 @@ class NoUncheckedPtrMemberChecker final : public RawPtrRefMemberChecker {
       : RawPtrRefMemberChecker("Member variable is a raw-pointer/reference to "
                                "checked-pointer capable type") {}
 
-  std::optional<bool> isUnsafePtr(QualType QT) const final {
+  std::optional<bool> isUnsafePtr(QualType QT, bool) const final {
     return isUncheckedPtr(QT.getCanonicalType());
   }
 
@@ -316,8 +318,8 @@ class NoUnretainedMemberChecker final : public RawPtrRefMemberChecker {
     RTC = RetainTypeChecker();
   }
 
-  std::optional<bool> isUnsafePtr(QualType QT) const final {
-    return RTC->isUnretained(QT);
+  std::optional<bool> isUnsafePtr(QualType QT, bool ignoreARC) const final {
+    return RTC->isUnretained(QT, ignoreARC);
   }
 
   const char *typeName() const final { return "retainable type"; }

clang/test/Analysis/Checkers/WebKit/unretained-members-arc.mm

@@ -65,6 +65,19 @@ void forceTmplToInstantiate(FooTmpl<SomeObj, CFMutableArrayRef>) {}
 
 } // namespace ptr_to_ptr_to_retained
 
+@interface AnotherObject : NSObject {
+  NSString *ns_string;
+  CFStringRef cf_string;
+  // expected-warning@-1{{Instance variable 'cf_string' in 'AnotherObject' is a retainable type 'CFStringRef'; member variables must be a RetainPtr}}
+}
+@property(nonatomic, strong) NSString *prop_string1;
+@property(nonatomic, assign) NSString *prop_string2;
+// expected-warning@-1{{Property 'prop_string2' in 'AnotherObject' is a raw pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@property(nonatomic, unsafe_unretained) NSString *prop_string3;
+// expected-warning@-1{{Property 'prop_string3' in 'AnotherObject' is a raw pointer to retainable type 'NSString'; member variables must be a RetainPtr}}
+@property(nonatomic, readonly) NSString *prop_string4;
+@end
+
 NS_REQUIRES_PROPERTY_DEFINITIONS
 @interface NoSynthObject : NSObject {
   NSString *ns_string;