[CIR] Fix multiple warnings across CIR codebase

Author: bcardosolopes

clang/lib/CIR/CodeGen/CIRGenBuilder.cpp

@@ -119,10 +119,10 @@ uint64_t CIRGenBuilderTy::computeOffsetFromGlobalViewIndices(
     llvm::ArrayRef<int64_t> indexes) {
 
   int64_t offset = 0;
-  for (auto idx : indexes) {
+  for (int64_t idx : indexes) {
     if (auto sTy = dyn_cast<cir::StructType>(typ)) {
       offset += sTy.getElementOffset(layout.layout, idx);
-      assert(idx < sTy.getMembers().size());
+      assert(idx < (int64_t)sTy.getMembers().size());
       typ = sTy.getMembers()[idx];
     } else if (auto arTy = dyn_cast<cir::ArrayType>(typ)) {
       typ = arTy.getEltType();

clang/lib/CIR/CodeGen/CIRGenItaniumCXXABI.cpp

@@ -2291,7 +2291,7 @@ void CIRGenItaniumCXXABI::emitRethrow(CIRGenFunction &CGF, bool isNoReturn) {
       builder.create<cir::BrOp>(loc, rethrowBlock);
     }
 
-    mlir::Block *remBlock = builder.createBlock(region);
+    (void)builder.createBlock(region);
     // This will be erased during codegen, it acts as a placeholder for the
     // operations to be inserted (if any)
     builder.create<cir::ScopeOp>(loc, /*scopeBuilder=*/

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -2457,7 +2457,7 @@ cir::FuncOp CIRGenModule::GetAddrOfFunction(clang::GlobalDecl gd, mlir::Type ty,
   // stub. For HIP, it's something different.
   if ((langOpts.HIP || langOpts.CUDA) && !langOpts.CUDAIsDevice &&
       cast<FunctionDecl>(gd.getDecl())->hasAttr<CUDAGlobalAttr>()) {
-    auto *stubHandle = getCUDARuntime().getKernelHandle(f, gd);
+    (void)getCUDARuntime().getKernelHandle(f, gd);
     if (isForDefinition)
       return f;
 
@@ -2678,12 +2678,6 @@ cir::FuncOp CIRGenModule::createRuntimeFunction(cir::FuncType ty,
   return entry;
 }
 
-static bool isDefaultedMethod(const clang::FunctionDecl *fd) {
-  return fd->isDefaulted() && isa<CXXMethodDecl>(fd) &&
-         (cast<CXXMethodDecl>(fd)->isCopyAssignmentOperator() ||
-          cast<CXXMethodDecl>(fd)->isMoveAssignmentOperator());
-}
-
 mlir::Location CIRGenModule::getLocForFunction(const clang::FunctionDecl *fd) {
   bool invalidLoc = !fd || (fd->getSourceRange().getBegin().isInvalid() ||
                             fd->getSourceRange().getEnd().isInvalid());

clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp

@@ -1109,7 +1109,7 @@ void LoweringPreparePass::buildCUDAModuleCtor() {
   // Corresponding code:
   //     gpuBinaryHandle = __cudaRegisterFatBinary(&fatbinWrapper);
   auto fatbinVoidPtr = builder.createBitcast(wrapper, voidPtrTy);
-  auto gpuBinaryHandle = builder.createCallOp(loc, regFunc, fatbinVoidPtr);
+  builder.createCallOp(loc, regFunc, fatbinVoidPtr);
 
   // This is currently incomplete.
   // TODO(cir): create __cuda_register_globals(), and call it here.

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -775,6 +775,8 @@ mlir::LLVM::CConv convertCallingConv(cir::CallingConv callinvConv) {
     return LLVM::SPIR_KERNEL;
   case CIR::SpirFunction:
     return LLVM::SPIR_FUNC;
+  case CIR::OpenCLKernel:
+    llvm_unreachable("NYI");
   }
   llvm_unreachable("Unknown calling convention");
 }
@@ -2383,7 +2385,6 @@ mlir::LogicalResult CIRToLLVMGlobalOpLowering::matchAndRewrite(
   const auto isDsoLocal = op.getDsolocal();
   const auto linkage = convertLinkage(op.getLinkage());
   const auto symbol = op.getSymName();
-  const auto loc = op.getLoc();
   std::optional<mlir::StringRef> section = op.getSection();
   std::optional<mlir::Attribute> init = op.getInitialValue();
   mlir::LLVM::VisibilityAttr visibility = mlir::LLVM::VisibilityAttr::get(