[mlir][ods] Fix generation of optional custom parsers (#84821)

We need to generate `.has_value` for `OptionalParseResult`, also ensure
that `auto result` doesn't conflict with `result` which is the variable
name for `OperationState`.

mlir/test/IR/custom-print-parse.mlir

@@ -14,4 +14,9 @@ module @dimension_list {
   test.custom_dimension_list_attr dimension_list = ?
   // CHECK: test.custom_dimension_list_attr dimension_list = ?x?
   test.custom_dimension_list_attr dimension_list = ?x?
+
+  // CHECK: test.optional_custom_attr
+  test.optional_custom_attr bar
+  // CHECK: test.optional_custom_attr foo false
+  test.optional_custom_attr foo false
 }

mlir/test/IR/invalid-custom-print-parse.mlir

@@ -14,3 +14,8 @@ test.custom_dimension_list_attr dimension_list = -1
 // expected-error@+2 {{expected ']'}}
 // expected-error@+1 {{custom op 'test.custom_dimension_list_attr' Failed parsing dimension list.}}
 test.custom_dimension_list_attr dimension_list = [2x3]
+
+// -----
+
+// expected-error @below {{expected attribute value}}
+test.optional_custom_attr foo

mlir/test/lib/Dialect/Test/TestDialect.cpp

@@ -499,6 +499,23 @@ void AffineScopeOp::print(OpAsmPrinter &p) {
   p.printRegion(getRegion(), /*printEntryBlockArgs=*/false);
 }
 
+//===----------------------------------------------------------------------===//
+// Test OptionalCustomAttrOp
+//===----------------------------------------------------------------------===//
+
+static OptionalParseResult parseOptionalCustomParser(AsmParser &p,
+                                                     IntegerAttr &result) {
+  if (succeeded(p.parseOptionalKeyword("foo")))
+    return p.parseAttribute(result);
+  return {};
+}
+
+static void printOptionalCustomParser(AsmPrinter &p, Operation *,
+                                      IntegerAttr result) {
+  p << "foo ";
+  p.printAttribute(result);
+}
+
 //===----------------------------------------------------------------------===//
 // Test removing op with inner ops.
 //===----------------------------------------------------------------------===//

mlir/test/lib/Dialect/Test/TestOps.td

@@ -2048,6 +2048,17 @@ def CustomDimensionListAttrOp : TEST_Op<"custom_dimension_list_attr"> {
   }];
 }
 
+def OptionalCustomAttrOp : TEST_Op<"optional_custom_attr"> {
+  let description = [{
+    Test using a custom directive as the optional group anchor and the first
+    element to parse. It is expected to return an `OptionalParseResult`.
+  }];
+  let arguments = (ins OptionalAttr<I1Attr>:$attr);
+  let assemblyFormat = [{
+    attr-dict (custom<OptionalCustomParser>($attr)^) : (`bar`)?
+  }];
+}
+
 //===----------------------------------------------------------------------===//
 // Test OpAsmInterface.
 

mlir/test/mlir-tblgen/attr-or-type-format.td

@@ -648,7 +648,7 @@ def TypeN : TestType<"TestP"> {
 // TYPE-LABEL: TestQType::parse
 // TYPE: if (auto result = [&]() -> ::mlir::OptionalParseResult {
 // TYPE:     auto odsCustomResult = parseAB(odsParser
-// TYPE:     if (!odsCustomResult) return {};
+// TYPE:     if (!odsCustomResult.has_value()) return {};
 // TYPE:     if (::mlir::failed(*odsCustomResult)) return ::mlir::failure();
 // TYPE:   return ::mlir::success();
 // TYPE: }(); result.has_value() && ::mlir::failed(*result)) {

mlir/test/mlir-tblgen/op-format.td

@@ -93,14 +93,14 @@ def OptionalGroupC : TestFormat_Op<[{
 }]>, Arguments<(ins DefaultValuedStrAttr<StrAttr, "default">:$a)>;
 
 // CHECK-LABEL: OptionalGroupD::parse
-// CHECK: if (auto result = [&]() -> ::mlir::OptionalParseResult {
+// CHECK: if (auto optResult = [&]() -> ::mlir::OptionalParseResult {
 // CHECK:   auto odsResult = parseCustom(parser, aOperand, bOperand);
-// CHECK:   if (!odsResult) return {};
+// CHECK:   if (!odsResult.has_value()) return {};
 // CHECK:   if (::mlir::failed(*odsResult)) return ::mlir::failure();
 // CHECK:   return ::mlir::success();
-// CHECK: }(); result.has_value() && ::mlir::failed(*result)) {
+// CHECK: }(); optResult.has_value() && ::mlir::failed(*optResult)) {
 // CHECK:   return ::mlir::failure();
-// CHECK: } else if (result.has_value()) {
+// CHECK: } else if (optResult.has_value()) {
 
 // CHECK-LABEL: OptionalGroupD::print
 // CHECK-NEXT: if (((getA()) || (getB()))) {

mlir/tools/mlir-tblgen/AttrOrTypeFormatGen.cpp

@@ -622,7 +622,7 @@ void DefFormat::genCustomParser(CustomDirective *el, FmtContext &ctx,
   }
   os.unindent() << ");\n";
   if (isOptional) {
-    os << "if (!odsCustomResult) return {};\n";
+    os << "if (!odsCustomResult.has_value()) return {};\n";
     os << "if (::mlir::failed(*odsCustomResult)) return ::mlir::failure();\n";
   } else {
     os << "if (::mlir::failed(odsCustomResult)) return {};\n";

mlir/tools/mlir-tblgen/OpFormatGen.cpp

@@ -1025,7 +1025,7 @@ static void genCustomDirectiveParser(CustomDirective *dir, MethodBody &body,
   body << ");\n";
 
   if (isOptional) {
-    body << "    if (!odsResult) return {};\n"
+    body << "    if (!odsResult.has_value()) return {};\n"
          << "    if (::mlir::failed(*odsResult)) return ::mlir::failure();\n";
   } else {
     body << "    if (odsResult) return ::mlir::failure();\n";
@@ -1285,13 +1285,13 @@ void OperationFormat::genElementParser(FormatElement *element, MethodBody &body,
                                 region->name);
       }
     } else if (auto *custom = dyn_cast<CustomDirective>(firstElement)) {
-      body << "  if (auto result = [&]() -> ::mlir::OptionalParseResult {\n";
+      body << "  if (auto optResult = [&]() -> ::mlir::OptionalParseResult {\n";
       genCustomDirectiveParser(custom, body, useProperties, opCppClassName,
                                /*isOptional=*/true);
       body << "    return ::mlir::success();\n"
-           << "  }(); result.has_value() && ::mlir::failed(*result)) {\n"
+           << "  }(); optResult.has_value() && ::mlir::failed(*optResult)) {\n"
            << "    return ::mlir::failure();\n"
-           << "  } else if (result.has_value()) {\n";
+           << "  } else if (optResult.has_value()) {\n";
     }
 
     genElementParsers(firstElement, thenElements.drop_front(),