[NFC][analyzer] Clean bug type use in BasicObjCFoundationChecks (#151141)

This commit eliminates some corrupted variants of the once-widespread
`mutable std::unique_ptr<BugType>` antipattern from the checker file
`BasicObjCFoundationChecks.cpp`.

Previous purges probably missed these because there are slight mutations
(e.g. using a subclass of `BugType` instead of `BugType`) and therefore
some natural search terms (e.g. `make_unique<BugType>`) didn't produce
matches in this file.

Author: NagyDonat

clang/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp

@@ -99,7 +99,7 @@ class NilArgChecker : public Checker<check::PreObjCMessage,
                                      check::PostStmt<ObjCDictionaryLiteral>,
                                      check::PostStmt<ObjCArrayLiteral>,
                                      EventDispatcher<ImplicitNullDerefEvent>> {
-  mutable std::unique_ptr<APIMisuse> BT;
+  const APIMisuse BT{this, "nil argument"};
 
   mutable llvm::SmallDenseMap<Selector, unsigned, 16> StringSelectors;
   mutable Selector ArrayWithObjectSel;
@@ -218,10 +218,7 @@ void NilArgChecker::generateBugReport(ExplodedNode *N,
                                       SourceRange Range,
                                       const Expr *E,
                                       CheckerContext &C) const {
-  if (!BT)
-    BT.reset(new APIMisuse(this, "nil argument"));
-
-  auto R = std::make_unique<PathSensitiveBugReport>(*BT, Msg, N);
+  auto R = std::make_unique<PathSensitiveBugReport>(BT, Msg, N);
   R->addRange(Range);
   bugreporter::trackExpressionValue(N, E, *R);
   C.emitReport(std::move(R));
@@ -350,7 +347,7 @@ void NilArgChecker::checkPostStmt(const ObjCDictionaryLiteral *DL,
 
 namespace {
 class CFNumberChecker : public Checker< check::PreStmt<CallExpr> > {
-  mutable std::unique_ptr<APIMisuse> BT;
+  const APIMisuse BT{this, "Bad use of CFNumber APIs"};
   mutable IdentifierInfo *ICreate = nullptr, *IGetValue = nullptr;
 public:
   CFNumberChecker() = default;
@@ -524,10 +521,7 @@ void CFNumberChecker::checkPreStmt(const CallExpr *CE,
       << " bits of the integer value will be "
       << (isCreate ? "lost." : "garbage.");
 
-    if (!BT)
-      BT.reset(new APIMisuse(this, "Bad use of CFNumber APIs"));
-
-    auto report = std::make_unique<PathSensitiveBugReport>(*BT, os.str(), N);
+    auto report = std::make_unique<PathSensitiveBugReport>(BT, os.str(), N);
     report->addRange(CE->getArg(2)->getSourceRange());
     C.emitReport(std::move(report));
   }
@@ -539,7 +533,7 @@ void CFNumberChecker::checkPreStmt(const CallExpr *CE,
 
 namespace {
 class CFRetainReleaseChecker : public Checker<check::PreCall> {
-  mutable APIMisuse BT{this, "null passed to CF memory management function"};
+  const APIMisuse BT{this, "null passed to CF memory management function"};
   const CallDescriptionSet ModelledCalls = {
       {CDM::CLibrary, {"CFRetain"}, 1},
       {CDM::CLibrary, {"CFRelease"}, 1},
@@ -600,7 +594,8 @@ class ClassReleaseChecker : public Checker<check::PreObjCMessage> {
   mutable Selector retainS;
   mutable Selector autoreleaseS;
   mutable Selector drainS;
-  mutable std::unique_ptr<BugType> BT;
+  const APIMisuse BT{
+      this, "message incorrectly sent to class instead of class instance"};
 
 public:
   void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
@@ -609,10 +604,7 @@ class ClassReleaseChecker : public Checker<check::PreObjCMessage> {
 
 void ClassReleaseChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
                                               CheckerContext &C) const {
-  if (!BT) {
-    BT.reset(new APIMisuse(
-        this, "message incorrectly sent to class instead of class instance"));
-
+  if (releaseS.isNull()) {
     ASTContext &Ctx = C.getASTContext();
     releaseS = GetNullarySelector("release", Ctx);
     retainS = GetNullarySelector("retain", Ctx);
@@ -639,7 +631,7 @@ void ClassReleaseChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
           "of class '" << Class->getName()
        << "' and not the class directly";
 
-    auto report = std::make_unique<PathSensitiveBugReport>(*BT, os.str(), N);
+    auto report = std::make_unique<PathSensitiveBugReport>(BT, os.str(), N);
     report->addRange(msg.getSourceRange());
     C.emitReport(std::move(report));
   }
@@ -658,7 +650,8 @@ class VariadicMethodTypeChecker : public Checker<check::PreObjCMessage> {
   mutable Selector orderedSetWithObjectsS;
   mutable Selector initWithObjectsS;
   mutable Selector initWithObjectsAndKeysS;
-  mutable std::unique_ptr<BugType> BT;
+  const APIMisuse BT{this, "Arguments passed to variadic method aren't all "
+                           "Objective-C pointer types"};
 
   bool isVariadicMessage(const ObjCMethodCall &msg) const;
 
@@ -717,11 +710,7 @@ VariadicMethodTypeChecker::isVariadicMessage(const ObjCMethodCall &msg) const {
 
 void VariadicMethodTypeChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
                                                     CheckerContext &C) const {
-  if (!BT) {
-    BT.reset(new APIMisuse(this,
-                           "Arguments passed to variadic method aren't all "
-                           "Objective-C pointer types"));
-
+  if (arrayWithObjectsS.isNull()) {
     ASTContext &Ctx = C.getASTContext();
     arrayWithObjectsS = GetUnarySelector("arrayWithObjects", Ctx);
     dictionaryWithObjectsAndKeysS =
@@ -792,8 +781,7 @@ void VariadicMethodTypeChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
     ArgTy.print(os, C.getLangOpts());
     os << "'";
 
-    auto R =
-        std::make_unique<PathSensitiveBugReport>(*BT, os.str(), *errorNode);
+    auto R = std::make_unique<PathSensitiveBugReport>(BT, os.str(), *errorNode);
     R->addRange(msg.getArgSourceRange(I));
     C.emitReport(std::move(R));
   }