[alpha.webkit.webkit.RetainPtrCtorAdoptChecker] Add a new WebKit checker for correct use of RetainPtr, adoptNS, and adoptCF (#128679)

Add a new WebKit checker to validate the correct use of RetainPtr
constructor as well as adoptNS and adoptCF functions. adoptNS and
adoptCf are used for +1 semantics and RetainPtr constructor is used for
+0 semantics.

Author: rniwa

clang/docs/analyzer/checkers.rst

@@ -3779,6 +3779,26 @@ Here are some examples of situations that we warn about as they *might* be poten
       NSObject* unretained = retained.get(); // warn
     }
 
+webkit.RetainPtrCtorAdoptChecker
+""""""""""""""""""""""""""""""""
+The goal of this rule is to make sure the constructor of RetainPtr as well as adoptNS and adoptCF are used correctly.
+When creating a RetainPtr with +1 semantics, adoptNS or adoptCF should be used, and in +0 semantics, RetainPtr constructor should be used.
+Warn otherwise.
+
+These are examples of cases that we consider correct:
+
+  .. code-block:: cpp
+
+    RetainPtr ptr = adoptNS([[NSObject alloc] init]); // ok
+    RetainPtr ptr = CGImageGetColorSpace(image); // ok
+
+Here are some examples of cases that we consider incorrect use of RetainPtr constructor and adoptCF
+
+  .. code-block:: cpp
+
+    RetainPtr ptr = [[NSObject alloc] init]; // warn
+    auto ptr = adoptCF(CGImageGetColorSpace(image)); // warn
+
 Debug Checkers
 ---------------
 

clang/include/clang/StaticAnalyzer/Checkers/Checkers.td

@@ -1801,4 +1801,8 @@ def UnretainedLocalVarsChecker : Checker<"UnretainedLocalVarsChecker">,
   HelpText<"Check unretained local variables.">,
   Documentation<HasDocumentation>;
 
+def RetainPtrCtorAdoptChecker : Checker<"RetainPtrCtorAdoptChecker">,
+  HelpText<"Check for correct use of RetainPtr constructor, adoptNS, and adoptCF">,
+  Documentation<HasDocumentation>;
+
 } // end alpha.webkit

clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt

@@ -133,6 +133,7 @@ add_clang_library(clangStaticAnalyzerCheckers
   WebKit/MemoryUnsafeCastChecker.cpp
   WebKit/PtrTypesSemantics.cpp
   WebKit/RefCntblBaseVirtualDtorChecker.cpp
+  WebKit/RetainPtrCtorAdoptChecker.cpp
   WebKit/RawPtrRefCallArgsChecker.cpp
   WebKit/RawPtrRefLambdaCapturesChecker.cpp
   WebKit/RawPtrRefLocalVarsChecker.cpp

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

@@ -226,15 +226,16 @@ void RetainTypeChecker::visitTypedef(const TypedefDecl *TD) {
     return;
 
   for (auto *Redecl : RT->getDecl()->getMostRecentDecl()->redecls()) {
-    if (Redecl->getAttr<ObjCBridgeAttr>()) {
+    if (Redecl->getAttr<ObjCBridgeAttr>() ||
+        Redecl->getAttr<ObjCBridgeMutableAttr>()) {
       CFPointees.insert(RT);
       return;
     }
   }
 }
 
-bool RetainTypeChecker::isUnretained(const QualType QT) {
-  if (ento::cocoa::isCocoaObjectRef(QT) && !IsARCEnabled)
+bool RetainTypeChecker::isUnretained(const QualType QT, bool ignoreARC) {
+  if (ento::cocoa::isCocoaObjectRef(QT) && (!IsARCEnabled || ignoreARC))
     return true;
   auto CanonicalType = QT.getCanonicalType();
   auto PointeeType = CanonicalType->getPointeeType();

clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.h

@@ -75,7 +75,8 @@ class RetainTypeChecker {
 public:
   void visitTranslationUnitDecl(const TranslationUnitDecl *);
   void visitTypedef(const TypedefDecl *);
-  bool isUnretained(const QualType);
+  bool isUnretained(const QualType, bool ignoreARC = false);
+  bool isARCEnabled() const { return IsARCEnabled; }
 };
 
 /// \returns true if \p Class is NS or CF objects AND not retained, false if