[analyzer][CallAndMessage][NFC] Change old callbacks to rely on CallEvent

[Szelethus]

Summary

The following series of patches has something similar in mind with D77474, with the same goal to finally end incorrect checker names for good. Despite CallAndMessage not suffering from this particular issue, it is a dependency for many other checkers, which is problematic, because we don't really want dependencies to also emit diagnostics (reasoning for this is also more detailed in D77474).

CallAndMessage also has another problem, namely that it is responsible for a lot of reports. You'll soon learn that this isn't really easy to solve for compatibility reasons, but that is the topic of followup patches.

[Szelethus]

clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp

113–114

Well, rG878194414107e94600de31a11be09a347fb2598b got this :)

clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp

 //===--- CallAndMessageChecker.cpp ------------------------------*- C++ -*--==//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This defines CallAndMessageChecker, a builtin checker that checks for various
 // errors of call and objc message expressions.
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "clang/AST/ExprCXX.h"
 #include "clang/AST/ParentMap.h"
 #include "clang/Basic/TargetInfo.h"
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace clang;
 using namespace ento;
 
 namespace {
 
 class CallAndMessageChecker
-  : public Checker< check::PreStmt<CallExpr>,
-                    check::PreStmt<CXXDeleteExpr>,
-                    check::PreObjCMessage,
-                    check::ObjCMessageNil,
-                    check::PreCall > {
+    : public Checker<check::PreObjCMessage, check::ObjCMessageNil,
+                     check::PreCall> {
   mutable std::unique_ptr<BugType> BT_call_null;
   mutable std::unique_ptr<BugType> BT_call_undef;
   mutable std::unique_ptr<BugType> BT_cxx_call_null;
   mutable std::unique_ptr<BugType> BT_cxx_call_undef;
   mutable std::unique_ptr<BugType> BT_call_arg;
   mutable std::unique_ptr<BugType> BT_cxx_delete_undef;
   mutable std::unique_ptr<BugType> BT_msg_undef;
   mutable std::unique_ptr<BugType> BT_objc_prop_undef;
   mutable std::unique_ptr<BugType> BT_objc_subscript_undef;
   mutable std::unique_ptr<BugType> BT_msg_arg;
   mutable std::unique_ptr<BugType> BT_msg_ret;
   mutable std::unique_ptr<BugType> BT_call_few_args;
 
 public:
-  DefaultBool Check_CallAndMessageUnInitRefArg;
-  CheckerNameRef CheckName_CallAndMessageUnInitRefArg;
+  enum CheckKind { CK_CallAndMessageUnInitRefArg, CK_NumCheckKinds };
+
+  DefaultBool ChecksEnabled[CK_NumCheckKinds];
 
-  void checkPreStmt(const CallExpr *CE, CheckerContext &C) const;
-  void checkPreStmt(const CXXDeleteExpr *DE, CheckerContext &C) const;
   void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
 
   /// Fill in the return value that results from messaging nil based on the
   /// return type and architecture and diagnose if the return value will be
   /// garbage.
   void checkObjCMessageNil(const ObjCMethodCall &msg, CheckerContext &C) const;
 
   void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
default:
     return;
   }
 }
 
 bool CallAndMessageChecker::uninitRefOrPointer(
     CheckerContext &C, const SVal &V, SourceRange ArgRange, const Expr *ArgEx,
     std::unique_ptr<BugType> &BT, const ParmVarDecl *ParamDecl, const char *BD,
     int ArgumentNumber) const {
-  if (!Check_CallAndMessageUnInitRefArg)
+  if (!ChecksEnabled[CK_CallAndMessageUnInitRefArg])
     return false;
 
   // No parameter declaration available, i.e. variadic function argument.
   if(!ParamDecl)
     return false;
 
   // If parameter is declared as pointer to const in function declaration,
   // then check if corresponding argument in function call is
if (F.Find(D->getRegion())) {
       }
       return true;
     }
   }
 
   return false;
 }
 
-void CallAndMessageChecker::checkPreStmt(const CallExpr *CE,
-                                         CheckerContext &C) const{
-
-  const Expr *Callee = CE->getCallee()->IgnoreParens();
+void CallAndMessageChecker::checkPreCall(const CallEvent &Call,
+                                         CheckerContext &C) const {
   ProgramStateRef State = C.getState();
+  if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr())) {
+    const Expr *Callee = CE->getCallee()->IgnoreParens();
     const LocationContext *LCtx = C.getLocationContext();
     SVal L = State->getSVal(Callee, LCtx);
 
     if (L.isUndef()) {
       if (!BT_call_undef)
         BT_call_undef.reset(new BuiltinBug(
             this, "Called function pointer is an uninitialized pointer value"));
       emitBadCall(BT_call_undef.get(), C, Callee);
       return;
     }
 
     ProgramStateRef StNonNull, StNull;
-  std::tie(StNonNull, StNull) = State->assume(L.castAs<DefinedOrUnknownSVal>());
+    std::tie(StNonNull, StNull) =
+        State->assume(L.castAs<DefinedOrUnknownSVal>());
 
     if (StNull && !StNonNull) {
       if (!BT_call_null)
         BT_call_null.reset(new BuiltinBug(
             this, "Called function pointer is null (null dereference)"));
       emitBadCall(BT_call_null.get(), C, Callee);
       return;
     }
 
-  C.addTransition(StNonNull);
-}
-
-void CallAndMessageChecker::checkPreStmt(const CXXDeleteExpr *DE,
-                                         CheckerContext &C) const {
-
-  SVal Arg = C.getSVal(DE->getArgument());
-  if (Arg.isUndef()) {
-    StringRef Desc;
-    ExplodedNode *N = C.generateErrorNode();
-    if (!N)
-      return;
-    if (!BT_cxx_delete_undef)
-      BT_cxx_delete_undef.reset(
-          new BuiltinBug(this, "Uninitialized argument value"));
-    if (DE->isArrayFormAsWritten())
-      Desc = "Argument to 'delete[]' is uninitialized";
-    else
-      Desc = "Argument to 'delete' is uninitialized";
-    BugType *BT = BT_cxx_delete_undef.get();
-    auto R = std::make_unique<PathSensitiveBugReport>(*BT, Desc, N);
-    bugreporter::trackExpressionValue(N, DE, *R);
-    C.emitReport(std::move(R));
-    return;
-  }
+    State = StNonNull;
   }
 
-void CallAndMessageChecker::checkPreCall(const CallEvent &Call,
-                                         CheckerContext &C) const {
-  ProgramStateRef State = C.getState();
-
   // If this is a call to a C++ method, check if the callee is null or
   // undefined.
   if (const CXXInstanceCall *CC = dyn_cast<CXXInstanceCall>(&Call)) {
     SVal V = CC->getCXXThisVal();
     if (V.isUndef()) {
       if (!BT_cxx_call_undef)
         BT_cxx_call_undef.reset(
             new BuiltinBug(this, "Called C++ object pointer is uninitialized"));
if (Call.getNumArgs() < Params) {
          << (Params == 1 ? "" : "s") << " is called with fewer ("
          << Call.getNumArgs() << ")";
 
       C.emitReport(std::make_unique<PathSensitiveBugReport>(*BT_call_few_args,
                                                             os.str(), N));
     }
   }
 
+  if (const auto *DC = dyn_cast<CXXDeallocatorCall>(&Call)) {
+    const CXXDeleteExpr *DE = DC->getOriginExpr();
+    assert(DE);
+    SVal Arg = C.getSVal(DE->getArgument());
+    if (Arg.isUndef()) {
+      StringRef Desc;
+      ExplodedNode *N = C.generateErrorNode();
+      if (!N)
+        return;
+      if (!BT_cxx_delete_undef)
+        BT_cxx_delete_undef.reset(
+            new BuiltinBug(this, "Uninitialized argument value"));
+      if (DE->isArrayFormAsWritten())
+        Desc = "Argument to 'delete[]' is uninitialized";
+      else
+        Desc = "Argument to 'delete' is uninitialized";
+      BugType *BT = BT_cxx_delete_undef.get();
+      auto R = std::make_unique<PathSensitiveBugReport>(*BT, Desc, N);
+      bugreporter::trackExpressionValue(N, DE, *R);
+      C.emitReport(std::move(R));
+      return;
+    }
+  }
+
   // Don't check for uninitialized field values in arguments if the
   // caller has a body that is available and we have the chance to inline it.
   // This is a hack, but is a reasonable compromise betweens sometimes warning
   // and sometimes not depending on if we decide to inline a function.
   const bool checkUninitFields =
     !(C.getAnalysisManager().shouldInlineCall() && (D && D->getBody()));
 
   std::unique_ptr<BugType> *BT;
   if (isa<ObjCMethodCall>(Call))
     BT = &BT_msg_arg;
   else
     BT = &BT_call_arg;
 
   const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D);
   for (unsigned i = 0, e = Call.getNumArgs(); i != e; ++i) {
     const ParmVarDecl *ParamDecl = nullptr;
     if(FD && i < FD->getNumParams())
       ParamDecl = FD->getParamDecl(i);
     if (PreVisitProcessArg(C, Call.getArgSVal(i), Call.getArgSourceRange(i),
-                           Call.getArgExpr(i), i,
-                           checkUninitFields, Call, *BT, ParamDecl))
+                           Call.getArgExpr(i), i, checkUninitFields, Call, *BT,
+                           ParamDecl))
       return;
   }
 
   // If we make it here, record our assumptions about the callee.
   C.addTransition(State);
 }
 
 void CallAndMessageChecker::checkPreObjCMessage(const ObjCMethodCall &msg,

 void ento::registerCallAndMessageChecker(CheckerManager &mgr) {
   mgr.registerChecker<CallAndMessageChecker>();
 }
 
 bool ento::shouldRegisterCallAndMessageChecker(const CheckerManager &mgr) {
   return true;
 }
 
-void ento::registerCallAndMessageUnInitRefArg(CheckerManager &mgr) {
-  CallAndMessageChecker *Checker = mgr.getChecker<CallAndMessageChecker>();
-  Checker->Check_CallAndMessageUnInitRefArg = true;
-  Checker->CheckName_CallAndMessageUnInitRefArg = mgr.getCurrentCheckerName();
-}
+#define REGISTER_CHECKER(name)                                                 \
+  void ento::register##name(CheckerManager &mgr) {                             \
+    CallAndMessageChecker *checker = mgr.getChecker<CallAndMessageChecker>();  \
+    checker->ChecksEnabled[CallAndMessageChecker::CK_##name] = true;           \
+                                                                               \
+  }                                                                            \
+                                                                               \
+  bool ento::shouldRegister##name(const CheckerManager &mgr) { return true; }
 
-bool ento::shouldRegisterCallAndMessageUnInitRefArg(const CheckerManager &mgr) {
-  return true;
-}
+REGISTER_CHECKER(CallAndMessageUnInitRefArg)

clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp

struct FunctionData {
     FunctionData() = delete;
     FunctionData(const FunctionData &) = default;
     FunctionData(FunctionData &&) = default;
     FunctionData &operator=(const FunctionData &) = delete;
     FunctionData &operator=(FunctionData &&) = delete;
 
     static Optional<FunctionData> create(const CallEvent &Call,
                                          const CheckerContext &C) {
-      assert(Call.getDecl());
+      if (!Call.getDecl())
+        return None;
       const FunctionDecl *FDecl = Call.getDecl()->getAsFunction();
       if (!FDecl || (FDecl->getKind() != Decl::Function &&
                      FDecl->getKind() != Decl::CXXMethod))
         return None;
 
       StringRef Name = C.getCalleeName(FDecl);
       std::string FullName = FDecl->getQualifiedNameAsString();
       if (Name.empty() || FullName.empty())