[StaticAnalyzer] Migrate away from PointerUnion::{is,get} (NFC) (#118421)

Note that PointerUnion::{is,get} have been soft deprecated in
PointerUnion.h:

  // FIXME: Replace the uses of is(), get() and dyn_cast() with
  //        isa<T>, cast<T> and the llvm::dyn_cast<T>

I'm not touching PointerUnion::dyn_cast for now because it's a bit
complicated; we could blindly migrate it to dyn_cast_if_present, but
we should probably use dyn_cast when the operand is known to be
non-null.

Author: kazutakahirata

clang/lib/StaticAnalyzer/Checkers/MallocSizeofChecker.cpp

@@ -211,9 +211,9 @@ class MallocSizeofChecker : public Checker<check::ASTCodeBody> {
           continue;
 
         const TypeSourceInfo *TSI = nullptr;
-        if (CallRec.CastedExprParent.is<const VarDecl *>()) {
-          TSI = CallRec.CastedExprParent.get<const VarDecl *>()
-                    ->getTypeSourceInfo();
+        if (const auto *VD =
+                dyn_cast<const VarDecl *>(CallRec.CastedExprParent)) {
+          TSI = VD->getTypeSourceInfo();
         } else {
           TSI = CallRec.ExplicitCastType;
         }

clang/lib/StaticAnalyzer/Core/BasicValueFactory.cpp

@@ -196,13 +196,13 @@ const PointerToMemberData *BasicValueFactory::accumCXXBase(
   const NamedDecl *ND = nullptr;
   llvm::ImmutableList<const CXXBaseSpecifier *> BaseSpecList;
 
-  if (PTMDT.isNull() || PTMDT.is<const NamedDecl *>()) {
-    if (PTMDT.is<const NamedDecl *>())
-      ND = PTMDT.get<const NamedDecl *>();
+  if (PTMDT.isNull() || isa<const NamedDecl *>(PTMDT)) {
+    if (const auto *NDP = dyn_cast_if_present<const NamedDecl *>(PTMDT))
+      ND = NDP;
 
     BaseSpecList = CXXBaseListFactory.getEmptyList();
   } else {
-    const PointerToMemberData *PTMD = PTMDT.get<const PointerToMemberData *>();
+    const auto *PTMD = cast<const PointerToMemberData *>(PTMDT);
     ND = PTMD->getDeclaratorDecl();
 
     BaseSpecList = PTMD->getCXXBaseList();

clang/lib/StaticAnalyzer/Core/ExplodedGraph.cpp

@@ -211,9 +211,9 @@ void ExplodedNode::NodeGroup::replaceNode(ExplodedNode *node) {
   assert(!getFlag());
 
   GroupStorage &Storage = reinterpret_cast<GroupStorage&>(P);
-  assert(Storage.is<ExplodedNode *>());
+  assert(isa<ExplodedNode *>(Storage));
   Storage = node;
-  assert(Storage.is<ExplodedNode *>());
+  assert(isa<ExplodedNode *>(Storage));
 }
 
 void ExplodedNode::NodeGroup::addNode(ExplodedNode *N, ExplodedGraph &G) {
@@ -222,23 +222,23 @@ void ExplodedNode::NodeGroup::addNode(ExplodedNode *N, ExplodedGraph &G) {
   GroupStorage &Storage = reinterpret_cast<GroupStorage&>(P);
   if (Storage.isNull()) {
     Storage = N;
-    assert(Storage.is<ExplodedNode *>());
+    assert(isa<ExplodedNode *>(Storage));
     return;
   }
 
   ExplodedNodeVector *V = Storage.dyn_cast<ExplodedNodeVector *>();
 
   if (!V) {
     // Switch from single-node to multi-node representation.
-    ExplodedNode *Old = Storage.get<ExplodedNode *>();
+    auto *Old = cast<ExplodedNode *>(Storage);
 
     BumpVectorContext &Ctx = G.getNodeAllocator();
     V = new (G.getAllocator()) ExplodedNodeVector(Ctx, 4);
     V->push_back(Old, Ctx);
 
     Storage = V;
     assert(!getFlag());
-    assert(Storage.is<ExplodedNodeVector *>());
+    assert(isa<ExplodedNodeVector *>(Storage));
   }
 
   V->push_back(N, G.getNodeAllocator());

clang/lib/StaticAnalyzer/Core/MemRegion.cpp

@@ -1068,10 +1068,10 @@ const VarRegion *MemRegionManager::getVarRegion(const VarDecl *D,
     llvm::PointerUnion<const StackFrameContext *, const VarRegion *> V =
       getStackOrCaptureRegionForDeclContext(LC, DC, D);
 
-    if (V.is<const VarRegion*>())
-      return V.get<const VarRegion*>();
+    if (const auto *VR = dyn_cast_if_present<const VarRegion *>(V))
+      return VR;
 
-    const auto *STC = V.get<const StackFrameContext *>();
+    const auto *STC = cast<const StackFrameContext *>(V);
 
     if (!STC) {
       // FIXME: Assign a more sensible memory space to static locals

clang/lib/StaticAnalyzer/Core/SVals.cpp

@@ -205,10 +205,10 @@ const NamedDecl *nonloc::PointerToMember::getDecl() const {
     return nullptr;
 
   const NamedDecl *ND = nullptr;
-  if (PTMD.is<const NamedDecl *>())
-    ND = PTMD.get<const NamedDecl *>();
+  if (const auto *NDP = dyn_cast<const NamedDecl *>(PTMD))
+    ND = NDP;
   else
-    ND = PTMD.get<const PointerToMemberData *>()->getDeclaratorDecl();
+    ND = cast<const PointerToMemberData *>(PTMD)->getDeclaratorDecl();
 
   return ND;
 }
@@ -227,16 +227,16 @@ nonloc::CompoundVal::iterator nonloc::CompoundVal::end() const {
 
 nonloc::PointerToMember::iterator nonloc::PointerToMember::begin() const {
   const PTMDataType PTMD = getPTMData();
-  if (PTMD.is<const NamedDecl *>())
+  if (isa<const NamedDecl *>(PTMD))
     return {};
-  return PTMD.get<const PointerToMemberData *>()->begin();
+  return cast<const PointerToMemberData *>(PTMD)->begin();
 }
 
 nonloc::PointerToMember::iterator nonloc::PointerToMember::end() const {
   const PTMDataType PTMD = getPTMData();
-  if (PTMD.is<const NamedDecl *>())
+  if (isa<const NamedDecl *>(PTMD))
     return {};
-  return PTMD.get<const PointerToMemberData *>()->end();
+  return cast<const PointerToMemberData *>(PTMD)->end();
 }
 
 //===----------------------------------------------------------------------===//