Remove redundant casts. NFC

So I wrote a clang-tidy check to lint out redundant `isa`, `cast`, and
`dyn_cast`s for fun. This is a portion of what it found for clang; I
plan to do similar cleanups in LLVM and other subprojects when I find
time.

Because of the volume of changes, I explicitly avoided making any change
that wasn't highly local and obviously correct to me (e.g. we still have
a number of foo(cast<Bar>(baz)) that I didn't touch, since overloading
is a thing and the cast<Bar> did actually change the type -- just up the
class hierarchy).

I also tried to leave the types we were cast<>ing to somewhere nearby,
in cases where it wasn't locally obvious what we were dealing with
before.

llvm-svn: 326416

13 files changed, 73 insertions, 74 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 05f5f73504e..e93e2ac0c0d 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -2398,7 +2398,7 @@ Expr *ASTContext::getBlockVarCopyInits(const VarDecl*VD) {
          "getBlockVarCopyInits - not __block var");
   llvm::DenseMap<const VarDecl*, Expr*>::iterator
     I = BlockVarCopyInits.find(VD);
-  return (I != BlockVarCopyInits.end()) ? cast<Expr>(I->second) : nullptr;
+  return (I != BlockVarCopyInits.end()) ? I->second : nullptr;
 }
 
 /// \brief Set the copy inialization expression of a block var decl.
@@ -6575,7 +6575,7 @@ void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string& S,
       SmallVector<const ObjCIvarDecl*, 32> Ivars;
       DeepCollectObjCIvars(OI, true, Ivars);
       for (unsigned i = 0, e = Ivars.size(); i != e; ++i) {
-        const FieldDecl *Field = cast<FieldDecl>(Ivars[i]);
+        const FieldDecl *Field = Ivars[i];
         if (Field->isBitField())
           getObjCEncodingForTypeImpl(Field->getType(), S, false, true, Field);
         else
@@ -6636,7 +6636,7 @@ void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string& S,
         SmallVector<const ObjCIvarDecl*, 32> Ivars;
         DeepCollectObjCIvars(OI, true, Ivars);
         for (unsigned i = 0, e = Ivars.size(); i != e; ++i) {
-          if (cast<FieldDecl>(Ivars[i]) == FD) {
+          if (Ivars[i] == FD) {
             S += '{';
             S += OI->getObjCRuntimeNameAsString();
             S += '}';
diff --git a/clang/lib/AST/CXXInheritance.cpp b/clang/lib/AST/CXXInheritance.cpp
index 24e96ba3801..9314cfde7c0 100644
--- a/clang/lib/AST/CXXInheritance.cpp
+++ b/clang/lib/AST/CXXInheritance.cpp
@@ -637,8 +637,7 @@ void FinalOverriderCollector::Collect(const CXXRecordDecl *RD,
                                OMEnd = BaseOverriders->end();
            OM != OMEnd;
            ++OM) {
-        const CXXMethodDecl *CanonOM
-          = cast<CXXMethodDecl>(OM->first->getCanonicalDecl());
+        const CXXMethodDecl *CanonOM = OM->first->getCanonicalDecl();
         Overriders[CanonOM].add(OM->second);
       }
     }
@@ -649,7 +648,7 @@ void FinalOverriderCollector::Collect(const CXXRecordDecl *RD,
     if (!M->isVirtual())
       continue;
 
-    CXXMethodDecl *CanonM = cast<CXXMethodDecl>(M->getCanonicalDecl());
+    CXXMethodDecl *CanonM = M->getCanonicalDecl();
     using OverriddenMethodsRange =
         llvm::iterator_range<CXXMethodDecl::method_iterator>;
     OverriddenMethodsRange OverriddenMethods = CanonM->overridden_methods();
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index eb2c770b5f4..b640dccbd85 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -312,12 +312,12 @@ LinkageComputer::getLVForTemplateArgumentList(ArrayRef<TemplateArgument> Args,
       LV.merge(getLVForType(*Arg.getAsType(), computation));
       continue;
 
-    case TemplateArgument::Declaration:
-      if (const auto *ND = dyn_cast<NamedDecl>(Arg.getAsDecl())) {
-        assert(!usesTypeVisibility(ND));
-        LV.merge(getLVForDecl(ND, computation));
-      }
+    case TemplateArgument::Declaration: {
+      const NamedDecl *ND = Arg.getAsDecl();
+      assert(!usesTypeVisibility(ND));
+      LV.merge(getLVForDecl(ND, computation));
       continue;
+    }
 
     case TemplateArgument::NullPtr:
       LV.merge(getTypeLinkageAndVisibility(Arg.getNullPtrType()));
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 76cc4bb060a..487386fdb5d 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -1827,9 +1827,10 @@ CXXMethodDecl *CXXMethodDecl::getDevirtualizedMethod(const Expr *Base,
   // We can devirtualize calls on an object accessed by a class member access
   // expression, since by C++11 [basic.life]p6 we know that it can't refer to
   // a derived class object constructed in the same location.
-  if (const MemberExpr *ME = dyn_cast<MemberExpr>(Base))
-    if (const ValueDecl *VD = dyn_cast<ValueDecl>(ME->getMemberDecl()))
-      return VD->getType()->isRecordType() ? DevirtualizedMethod : nullptr;
+  if (const MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
+    const ValueDecl *VD = ME->getMemberDecl();
+    return VD->getType()->isRecordType() ? DevirtualizedMethod : nullptr;
+  }
 
   // Likewise for calls on an object accessed by a (non-reference) pointer to
   // member access.
diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp
index e82144b0ae9..87cee798659 100644
--- a/clang/lib/AST/DeclPrinter.cpp
+++ b/clang/lib/AST/DeclPrinter.cpp
@@ -1527,7 +1527,7 @@ void DeclPrinter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
                                                 E = D->varlist_end();
                                                 I != E; ++I) {
       Out << (I == D->varlist_begin() ? '(' : ',');
-      NamedDecl *ND = cast<NamedDecl>(cast<DeclRefExpr>(*I)->getDecl());
+      NamedDecl *ND = cast<DeclRefExpr>(*I)->getDecl();
       ND->printQualifiedName(Out);
     }
     Out << ")";
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 66f61708c5a..1813dfbe74c 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -3458,10 +3458,11 @@ FieldDecl *Expr::getSourceBitField() {
       if (Field->isBitField())
         return Field;
 
-  if (ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(E))
-    if (FieldDecl *Ivar = dyn_cast<FieldDecl>(IvarRef->getDecl()))
-      if (Ivar->isBitField())
-        return Ivar;
+  if (ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(E)) {
+    FieldDecl *Ivar = IvarRef->getDecl();
+    if (Ivar->isBitField())
+      return Ivar;
+  }
 
   if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E)) {
     if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 3d44d3369d0..45df133ad57 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -10433,7 +10433,7 @@ static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
   case Expr::DeclRefExprClass: {
     if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
       return NoDiag();
-    const ValueDecl *D = dyn_cast<ValueDecl>(cast<DeclRefExpr>(E)->getDecl());
+    const ValueDecl *D = cast<DeclRefExpr>(E)->getDecl();
     if (Ctx.getLangOpts().CPlusPlus &&
         D && IsConstNonVolatile(D->getType())) {
       // Parameter variables are never constants.  Without this check,
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 3c7e26d4137..d6d3792b6af 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -1324,8 +1324,7 @@ void CXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
 
     if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
       // We must have an anonymous union or struct declaration.
-      const RecordDecl *RD =
-        cast<RecordDecl>(VD->getType()->getAs<RecordType>()->getDecl());
+      const RecordDecl *RD = VD->getType()->getAs<RecordType>()->getDecl();
 
       // Itanium C++ ABI 5.1.2:
       //
diff --git a/clang/lib/AST/MicrosoftCXXABI.cpp b/clang/lib/AST/MicrosoftCXXABI.cpp
index b19491f3130..6d73716e131 100644
--- a/clang/lib/AST/MicrosoftCXXABI.cpp
+++ b/clang/lib/AST/MicrosoftCXXABI.cpp
@@ -106,7 +106,7 @@ public:
   void addTypedefNameForUnnamedTagDecl(TagDecl *TD,
                                        TypedefNameDecl *DD) override {
     TD = TD->getCanonicalDecl();
-    DD = cast<TypedefNameDecl>(DD->getCanonicalDecl());
+    DD = DD->getCanonicalDecl();
     TypedefNameDecl *&I = UnnamedTagDeclToTypedefNameDecl[TD];
     if (!I)
       I = DD;
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index a6ff13d9ddf..068254abd19 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -1368,7 +1368,7 @@ void MicrosoftCXXNameMangler::mangleTemplateArg(const TemplateDecl *TD,
     break;
   }
   case TemplateArgument::Declaration: {
-    const NamedDecl *ND = cast<NamedDecl>(TA.getAsDecl());
+    const NamedDecl *ND = TA.getAsDecl();
     if (isa<FieldDecl>(ND) || isa<IndirectFieldDecl>(ND)) {
       mangleMemberDataPointer(
           cast<CXXRecordDecl>(ND->getDeclContext())->getMostRecentDecl(),
diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
index a882c5ee9fa..c085b4d0c58 100644
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -3016,7 +3016,7 @@ const CXXMethodDecl *ASTContext::getCurrentKeyFunction(const CXXRecordDecl *RD)
     return nullptr;
 
   assert(RD->getDefinition() && "Cannot get key function for forward decl!");
-  RD = cast<CXXRecordDecl>(RD->getDefinition());
+  RD = RD->getDefinition();
 
   // Beware:
   //  1) computing the key function might trigger deserialization, which might
diff --git a/clang/lib/AST/TemplateBase.cpp b/clang/lib/AST/TemplateBase.cpp
index e81c11a7782..7ed6bf1c7b7 100644
--- a/clang/lib/AST/TemplateBase.cpp
+++ b/clang/lib/AST/TemplateBase.cpp
@@ -406,7 +406,7 @@ void TemplateArgument::print(const PrintingPolicy &Policy,
   }
     
   case Declaration: {
-    NamedDecl *ND = cast<NamedDecl>(getAsDecl());
+    NamedDecl *ND = getAsDecl();
     Out << '&';
     if (ND->getDeclName()) {
       // FIXME: distinguish between pointer and reference args?
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index f6cbe9d7088..da7fdb0ee14 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -1123,57 +1123,56 @@ QualType QualType::substObjCTypeArgs(
     // Replace an Objective-C type parameter reference with the corresponding
     // type argument.
     if (const auto *OTPTy = dyn_cast<ObjCTypeParamType>(splitType.Ty)) {
-      if (auto *typeParam = dyn_cast<ObjCTypeParamDecl>(OTPTy->getDecl())) {
-        // If we have type arguments, use them.
-        if (!typeArgs.empty()) {
-          QualType argType = typeArgs[typeParam->getIndex()];
-          if (OTPTy->qual_empty())
-            return ctx.getQualifiedType(argType, splitType.Quals);
-
-          // Apply protocol lists if exists.
-          bool hasError;
-          SmallVector<ObjCProtocolDecl*, 8> protocolsVec;
-          protocolsVec.append(OTPTy->qual_begin(),
-                              OTPTy->qual_end());
-          ArrayRef<ObjCProtocolDecl *> protocolsToApply = protocolsVec;
-          QualType resultTy = ctx.applyObjCProtocolQualifiers(argType,
-              protocolsToApply, hasError, true/*allowOnPointerType*/);
-
-          return ctx.getQualifiedType(resultTy, splitType.Quals);
-        }
+      ObjCTypeParamDecl *typeParam = OTPTy->getDecl();
+      // If we have type arguments, use them.
+      if (!typeArgs.empty()) {
+        QualType argType = typeArgs[typeParam->getIndex()];
+        if (OTPTy->qual_empty())
+          return ctx.getQualifiedType(argType, splitType.Quals);
+
+        // Apply protocol lists if exists.
+        bool hasError;
+        SmallVector<ObjCProtocolDecl*, 8> protocolsVec;
+        protocolsVec.append(OTPTy->qual_begin(),
+                            OTPTy->qual_end());
+        ArrayRef<ObjCProtocolDecl *> protocolsToApply = protocolsVec;
+        QualType resultTy = ctx.applyObjCProtocolQualifiers(argType,
+            protocolsToApply, hasError, true/*allowOnPointerType*/);
+
+        return ctx.getQualifiedType(resultTy, splitType.Quals);
+      }
 
-        switch (context) {
-        case ObjCSubstitutionContext::Ordinary:
-        case ObjCSubstitutionContext::Parameter:
-        case ObjCSubstitutionContext::Superclass:
-          // Substitute the bound.
+      switch (context) {
+      case ObjCSubstitutionContext::Ordinary:
+      case ObjCSubstitutionContext::Parameter:
+      case ObjCSubstitutionContext::Superclass:
+        // Substitute the bound.
+        return ctx.getQualifiedType(typeParam->getUnderlyingType(),
+                                    splitType.Quals);
+
+      case ObjCSubstitutionContext::Result:
+      case ObjCSubstitutionContext::Property: {
+        // Substitute the __kindof form of the underlying type.
+        const auto *objPtr = typeParam->getUnderlyingType()
+          ->castAs<ObjCObjectPointerType>();
+
+        // __kindof types, id, and Class don't need an additional
+        // __kindof.
+        if (objPtr->isKindOfType() || objPtr->isObjCIdOrClassType())
           return ctx.getQualifiedType(typeParam->getUnderlyingType(),
                                       splitType.Quals);
 
-        case ObjCSubstitutionContext::Result:
-        case ObjCSubstitutionContext::Property: {
-          // Substitute the __kindof form of the underlying type.
-          const auto *objPtr = typeParam->getUnderlyingType()
-            ->castAs<ObjCObjectPointerType>();
-
-          // __kindof types, id, and Class don't need an additional
-          // __kindof.
-          if (objPtr->isKindOfType() || objPtr->isObjCIdOrClassType())
-            return ctx.getQualifiedType(typeParam->getUnderlyingType(),
-                                        splitType.Quals);
-
-          // Add __kindof.
-          const auto *obj = objPtr->getObjectType();
-          QualType resultTy = ctx.getObjCObjectType(obj->getBaseType(),
-                                                    obj->getTypeArgsAsWritten(),
-                                                    obj->getProtocols(),
-                                                    /*isKindOf=*/true);
-
-          // Rebuild object pointer type.
-          resultTy = ctx.getObjCObjectPointerType(resultTy);
-          return ctx.getQualifiedType(resultTy, splitType.Quals);
-        }
-        }
+        // Add __kindof.
+        const auto *obj = objPtr->getObjectType();
+        QualType resultTy = ctx.getObjCObjectType(obj->getBaseType(),
+                                                  obj->getTypeArgsAsWritten(),
+                                                  obj->getProtocols(),
+                                                  /*isKindOf=*/true);
+
+        // Rebuild object pointer type.
+        resultTy = ctx.getObjCObjectPointerType(resultTy);
+        return ctx.getQualifiedType(resultTy, splitType.Quals);
+      }
       }
     }
 
@@ -1593,7 +1592,7 @@ CXXRecordDecl *Type::getAsCXXRecordDecl() const {
 
 TagDecl *Type::getAsTagDecl() const {
   if (const auto *TT = getAs<TagType>())
-    return cast<TagDecl>(TT->getDecl());
+    return TT->getDecl();
   if (const auto *Injected = getAs<InjectedClassNameType>())
     return Injected->getDecl();