[analyzer] Conversion to CheckerFamily: StackAddrEscapeChecker

This commit converts the class StackAddrEscapeChecker to the checker
family framework and slightly simplifies the implementation.

This commit is almost NFC, the only technically "functional" change is
that it removes the hidden modeling checker `core.StackAddrEscapeBase`
which was only relevant as an implementation detail of the old checker
registration procedure.

Author: NagyDonat

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

@@ -233,15 +233,11 @@ def UndefResultChecker : Checker<"UndefinedBinaryOperatorResult">,
   HelpText<"Check for undefined results of binary operators">,
   Documentation<HasDocumentation>;
 
-def StackAddrEscapeBase : Checker<"StackAddrEscapeBase">,
-  HelpText<"Generate information about stack address escapes.">,
-  Documentation<NotDocumented>,
-  Hidden;
-
-def StackAddrEscapeChecker : Checker<"StackAddressEscape">,
-  HelpText<"Check that addresses to stack memory do not escape the function">,
-  Dependencies<[StackAddrEscapeBase]>,
-  Documentation<HasDocumentation>;
+def StackAddrEscapeChecker
+    : Checker<"StackAddressEscape">,
+      HelpText<
+          "Check that addresses to stack memory do not escape the function">,
+      Documentation<HasDocumentation>;
 
 def DynamicTypePropagation : Checker<"DynamicTypePropagation">,
   HelpText<"Generate dynamic type information">,
@@ -295,10 +291,11 @@ def DynamicTypeChecker
       Dependencies<[DynamicTypePropagation]>,
       Documentation<HasDocumentation>;
 
-def StackAddrAsyncEscapeChecker : Checker<"StackAddressAsyncEscape">,
-  HelpText<"Check that addresses to stack memory do not escape the function">,
-  Dependencies<[StackAddrEscapeBase]>,
-  Documentation<HasDocumentation>;
+def StackAddrAsyncEscapeChecker
+    : Checker<"StackAddressAsyncEscape">,
+      HelpText<
+          "Check that addresses to stack memory do not escape the function">,
+      Documentation<HasDocumentation>;
 
 def PthreadLockBase : Checker<"PthreadLockBase">,
   HelpText<"Helper registering multiple checks.">,

clang/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp

@@ -28,23 +28,20 @@ using namespace ento;
 
 namespace {
 class StackAddrEscapeChecker
-    : public Checker<check::PreCall, check::PreStmt<ReturnStmt>,
-                     check::EndFunction> {
+    : public CheckerFamily<check::PreCall, check::PreStmt<ReturnStmt>,
+                           check::EndFunction> {
   mutable IdentifierInfo *dispatch_semaphore_tII = nullptr;
-  mutable std::unique_ptr<BugType> BT_stackleak;
-  mutable std::unique_ptr<BugType> BT_returnstack;
-  mutable std::unique_ptr<BugType> BT_capturedstackasync;
-  mutable std::unique_ptr<BugType> BT_capturedstackret;
 
 public:
-  enum CheckKind {
-    CK_StackAddrEscapeChecker,
-    CK_StackAddrAsyncEscapeChecker,
-    CK_NumCheckKinds
-  };
+  StringRef getDebugTag() const override { return "StackAddrEscapeChecker"; }
 
-  bool ChecksEnabled[CK_NumCheckKinds] = {false};
-  CheckerNameRef CheckNames[CK_NumCheckKinds];
+  CheckerFrontend StackAddrEscape, StackAddrAsyncEscape;
+  const BugType StackLeak{&StackAddrEscape,
+                          "Stack address leaks outside of stack frame"};
+  const BugType ReturnStack{&StackAddrEscape,
+                            "Return of address to stack-allocated memory"};
+  const BugType CapturedStackAsync{
+      &StackAddrAsyncEscape, "Address of stack-allocated memory is captured"};
 
   void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
   void checkPreStmt(const ReturnStmt *RS, CheckerContext &C) const;
@@ -170,10 +167,6 @@ void StackAddrEscapeChecker::EmitReturnLeakError(CheckerContext &C,
   ExplodedNode *N = C.generateNonFatalErrorNode();
   if (!N)
     return;
-  if (!BT_returnstack)
-    BT_returnstack = std::make_unique<BugType>(
-        CheckNames[CK_StackAddrEscapeChecker],
-        "Return of address to stack-allocated memory");
 
   // Generate a report for this bug.
   SmallString<128> buf;
@@ -184,7 +177,7 @@ void StackAddrEscapeChecker::EmitReturnLeakError(CheckerContext &C,
   EmitReturnedAsPartOfError(os, C.getSVal(RetE), R);
 
   auto report =
-      std::make_unique<PathSensitiveBugReport>(*BT_returnstack, os.str(), N);
+      std::make_unique<PathSensitiveBugReport>(ReturnStack, os.str(), N);
   report->addRange(RetE->getSourceRange());
   if (range.isValid())
     report->addRange(range);
@@ -215,16 +208,12 @@ void StackAddrEscapeChecker::checkAsyncExecutedBlockCaptures(
     ExplodedNode *N = C.generateNonFatalErrorNode();
     if (!N)
       continue;
-    if (!BT_capturedstackasync)
-      BT_capturedstackasync = std::make_unique<BugType>(
-          CheckNames[CK_StackAddrAsyncEscapeChecker],
-          "Address of stack-allocated memory is captured");
     SmallString<128> Buf;
     llvm::raw_svector_ostream Out(Buf);
     SourceRange Range = genName(Out, Region, C.getASTContext());
     Out << " is captured by an asynchronously-executed block";
-    auto Report = std::make_unique<PathSensitiveBugReport>(
-        *BT_capturedstackasync, Out.str(), N);
+    auto Report = std::make_unique<PathSensitiveBugReport>(CapturedStackAsync,
+                                                           Out.str(), N);
     if (Range.isValid())
       Report->addRange(Range);
     C.emitReport(std::move(Report));
@@ -233,7 +222,7 @@ void StackAddrEscapeChecker::checkAsyncExecutedBlockCaptures(
 
 void StackAddrEscapeChecker::checkPreCall(const CallEvent &Call,
                                           CheckerContext &C) const {
-  if (!ChecksEnabled[CK_StackAddrAsyncEscapeChecker])
+  if (!StackAddrAsyncEscape.isEnabled())
     return;
   if (!Call.isGlobalCFunction("dispatch_after") &&
       !Call.isGlobalCFunction("dispatch_async"))
@@ -357,7 +346,7 @@ FindEscapingStackRegions(CheckerContext &C, const Expr *RetE, SVal RetVal) {
 
 void StackAddrEscapeChecker::checkPreStmt(const ReturnStmt *RS,
                                           CheckerContext &C) const {
-  if (!ChecksEnabled[CK_StackAddrEscapeChecker])
+  if (!StackAddrEscape.isEnabled())
     return;
 
   const Expr *RetE = RS->getRetValue();
@@ -456,7 +445,7 @@ static bool isInvalidatedSymbolRegion(const MemRegion *Region) {
 
 void StackAddrEscapeChecker::checkEndFunction(const ReturnStmt *RS,
                                               CheckerContext &Ctx) const {
-  if (!ChecksEnabled[CK_StackAddrEscapeChecker])
+  if (!StackAddrEscape.isEnabled())
     return;
 
   ExplodedNode *Node = Ctx.getPredecessor();
@@ -581,11 +570,6 @@ void StackAddrEscapeChecker::checkEndFunction(const ReturnStmt *RS,
   if (!N)
     return;
 
-  if (!BT_stackleak)
-    BT_stackleak =
-        std::make_unique<BugType>(CheckNames[CK_StackAddrEscapeChecker],
-                                  "Stack address leaks outside of stack frame");
-
   for (const auto &P : Cb.V) {
     const MemRegion *Referrer = P.first->getBaseRegion();
     const MemRegion *Referred = P.second;
@@ -604,7 +588,7 @@ void StackAddrEscapeChecker::checkEndFunction(const ReturnStmt *RS,
       Out << " is still referred to by a temporary object on the stack"
           << CommonSuffix;
       auto Report =
-          std::make_unique<PathSensitiveBugReport>(*BT_stackleak, Out.str(), N);
+          std::make_unique<PathSensitiveBugReport>(StackLeak, Out.str(), N);
       if (Range.isValid())
         Report->addRange(Range);
       Ctx.emitReport(std::move(Report));
@@ -618,31 +602,22 @@ void StackAddrEscapeChecker::checkEndFunction(const ReturnStmt *RS,
 
     Out << " is still referred to by the " << *ReferrerVariable << CommonSuffix;
     auto Report =
-        std::make_unique<PathSensitiveBugReport>(*BT_stackleak, Out.str(), N);
+        std::make_unique<PathSensitiveBugReport>(StackLeak, Out.str(), N);
     if (Range.isValid())
       Report->addRange(Range);
 
     Ctx.emitReport(std::move(Report));
   }
 }
 
-void ento::registerStackAddrEscapeBase(CheckerManager &mgr) {
-  mgr.registerChecker<StackAddrEscapeChecker>();
-}
-
-bool ento::shouldRegisterStackAddrEscapeBase(const CheckerManager &mgr) {
-  return true;
-}
-
-#define REGISTER_CHECKER(name)                                                 \
-  void ento::register##name(CheckerManager &Mgr) {                             \
-    StackAddrEscapeChecker *Chk = Mgr.getChecker<StackAddrEscapeChecker>();    \
-    Chk->ChecksEnabled[StackAddrEscapeChecker::CK_##name] = true;              \
-    Chk->CheckNames[StackAddrEscapeChecker::CK_##name] =                       \
-        Mgr.getCurrentCheckerName();                                           \
+#define REGISTER_CHECKER(NAME)                                                 \
+  void ento::register##NAME##Checker(CheckerManager &Mgr) {                    \
+    Mgr.getChecker<StackAddrEscapeChecker>()->NAME.enable(Mgr);                \
   }                                                                            \
                                                                                \
-  bool ento::shouldRegister##name(const CheckerManager &mgr) { return true; }
+  bool ento::shouldRegister##NAME##Checker(const CheckerManager &) {           \
+    return true;                                                               \
+  }
 
-REGISTER_CHECKER(StackAddrEscapeChecker)
-REGISTER_CHECKER(StackAddrAsyncEscapeChecker)
+REGISTER_CHECKER(StackAddrEscape)
+REGISTER_CHECKER(StackAddrAsyncEscape)

clang/test/Analysis/analyzer-enabled-checkers.c

@@ -20,7 +20,6 @@
 // CHECK-NEXT: core.NonNullParamChecker
 // CHECK-NEXT: core.NonnilStringConstants
 // CHECK-NEXT: core.NullDereference
-// CHECK-NEXT: core.StackAddrEscapeBase
 // CHECK-NEXT: core.StackAddressEscape
 // CHECK-NEXT: core.UndefinedBinaryOperatorResult
 // CHECK-NEXT: core.VLASize

clang/test/Analysis/std-c-library-functions-arg-enabled-checkers.c

@@ -28,7 +28,6 @@
 // CHECK-NEXT: core.NonNullParamChecker
 // CHECK-NEXT: core.NonnilStringConstants
 // CHECK-NEXT: core.NullDereference
-// CHECK-NEXT: core.StackAddrEscapeBase
 // CHECK-NEXT: core.StackAddressEscape
 // CHECK-NEXT: core.UndefinedBinaryOperatorResult
 // CHECK-NEXT: core.VLASize