[mlir] Cleanup: Fix warnings in MLIR

[springerm]

Summary

Tested with gcc-10. Other compilers may generate additional warnings. This does not fix all warnings. There are a few extra ones in LLVMCore and MLIR.

• OpEmitter::getAttrNameIndex: -Wunused-function (function is private and not used anywhere)
• PrintOpPass copy constructor: -Wextra ("Base class should be explicitly initialized in the copy constructor")
• LegalizeForLLVMExport.cpp: -Woverflow (overflow is expected, silence warning by making the cast explicit)

Depends On D107520

[rriddle]

mlir/lib/Transforms/ViewOpGraph.cpp

75

mlir/lib/Dialect/X86Vector/Transforms/LegalizeForLLVMExport.cpp

struct DotOpConversion : public ConvertOpToLLVMPattern<DotOp> {
 
   LogicalResult
   matchAndRewrite(DotOp op, ArrayRef<Value> operands,
                   ConversionPatternRewriter &rewriter) const override {
     DotOp::Adaptor adaptor(operands);
     auto opType = adaptor.a().getType();
     Type llvmIntType = IntegerType::get(&getTypeConverter()->getContext(), 8);
     // Dot product of all elements, broadcasted to all elements.
-    auto attr = rewriter.getI8IntegerAttr(0xff);
+    auto attr = rewriter.getI8IntegerAttr(static_cast<int8_t>(0xff));
     Value scale =
         rewriter.create<LLVM::ConstantOp>(op.getLoc(), llvmIntType, attr);
     rewriter.replaceOpWithNewOp<DotIntrOp>(op, opType, adaptor.a(), adaptor.b(),
                                            scale);
     return success();
   }
 };
 

mlir/lib/Transforms/ViewOpGraph.cpp

 };
 
 /// This pass generates a Graphviz dataflow visualization of an MLIR operation.
 /// Note: See https://www.graphviz.org/doc/info/lang.html for more information
 /// about the Graphviz DOT language.
 class PrintOpPass : public ViewOpGraphPassBase<PrintOpPass> {
 public:
   PrintOpPass(raw_ostream &os) : os(os) {}
-  PrintOpPass(const PrintOpPass &o) : os(o.os.getOStream()) {}
+  PrintOpPass(const PrintOpPass &o) : PrintOpPass(o.os.getOStream()) {}
 
   void runOnOperation() override {
     emitGraph([&]() {
       processOperation(getOperation());
       emitAllEdgeStmts();
     });
   }
 
   /// Create a CFG graph for a region. Used in `Region::viewGraph`.

mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp

OpEmitter(const Operator &op,
             const StaticVerifierFunctionEmitter &staticVerifierEmitter);
 
   void emitDecl(raw_ostream &os);
   void emitDef(raw_ostream &os);
 
   // Generate methods for accessing the attribute names of this operation.
   void genAttrNameGetters();
 
-  // Return the index of the given attribute name. This is a relative ordering
-  // for this name, used in attribute getters.
-  unsigned getAttrNameIndex(StringRef attrName) const;
-
   // Generates the OpAsmOpInterface for this operation if possible.
   void genOpAsmInterface();
 
   // Generates the `getOperationName` method for this op.
   void genOpNameGetter();
 
   // Generates getters for the attributes.
   void genAttrGetters();
// Generate the static variant.
           "::mlir::OperationName", "name");
       method->body() << llvm::formatv(attrNameMethodBody,
                                       "name, " + Twine(attrIt.second))
                             .str();
     }
   }
 }
 
-unsigned OpEmitter::getAttrNameIndex(StringRef attrName) const {
-  auto it = attributeNames.find(attrName);
-  assert(it != attributeNames.end() && "expected attribute name to have been "
-                                       "registered in genAttrNameGetters");
-  return it->second;
-}
-
 void OpEmitter::genAttrGetters() {
   FmtContext fctx;
   fctx.withBuilder("::mlir::Builder((*this)->getContext())");
 
   // Emit the derived attribute body.
   auto emitDerivedAttr = [&](StringRef name, Attribute attr) {
     if (auto *method = opClass.addMethodAndPrune(attr.getReturnType(), name))
       method->body() << "  " << attr.getDerivedCodeBody() << "\n";