[TableGen] Use result names in build() methods if possible

This will make it clear which result's type we are expecting in the build() signature.

PiperOrigin-RevId: 235925706

2 files changed, 47 insertions, 5 deletions

diff --git a/mlir/test/mlir-tblgen/op-result.td b/mlir/test/mlir-tblgen/op-result.td
new file mode 100644
index 00000000000..d9484fd4b7c
--- /dev/null
+++ b/mlir/test/mlir-tblgen/op-result.td
@@ -0,0 +1,32 @@
+// RUN: mlir-tblgen -gen-op-definitions -I %S/../../include %s | FileCheck %s
+
+include "mlir/IR/op_base.td"
+
+def SameTypeOp : Op<"same_type_op", [SameValueType]> {
+  let arguments = (ins I32:$x);
+  let results = (outs I32:$y);
+}
+
+// CHECK-LABEL: class SameTypeOp
+// CHECK: void build(Builder *builder, OperationState *result, Type y, Value *x)
+// CHECK:   result->addTypes({y});
+// CHECK: void build(Builder *builder, OperationState *result, Value *x)
+// CHECK:   result->addTypes({x->getType()});
+
+def ThreeResultOp : Op<"three_result_op", []> {
+  let results = (outs I32:$x, /*unnamed*/I32, I32:$z);
+}
+
+// CHECK-LABEL: class ThreeResultOp
+// CHECK: void build(Builder *builder, OperationState *result, Type x, Type resultType1, Type z)
+// CHECK:   result->addTypes({x, resultType1, z});
+
+def VariadicResultOp : Op<"variadic_op", []> {
+  let results = (outs I32:$x, Variadic<I32>:$y);
+}
+
+// CHECK-LABEL: VariadicResultOp
+// CHECK: void build(Builder *builder, OperationState *result, Type x, ArrayRef<Type> y)
+// CHECK:   result->addTypes({x});
+// CHECK:   result->addTypes(y);
+           
diff --git a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
index a8275eee146..35840dade9e 100644
--- a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
@@ -246,11 +246,21 @@ void OpEmitter::emitStandaloneParamBuilder(bool isAllSameType) {
   auto numResults = op.getNumResults();
   auto numOperands = op.getNumOperands();
 
+  llvm::SmallVector<std::string, 4> resultNames;
+  resultNames.reserve(numResults);
+
   // Emit parameters for all return types
   if (!isAllSameType) {
-    for (unsigned i = 0; i != numResults; ++i)
+    for (unsigned i = 0; i != numResults; ++i) {
+      std::string resultName = op.getResultName(i);
+      if (resultName.empty())
+        resultName = formatv("resultType{0}", i);
+
       os << (op.getResultType(i).isVariadic() ? ", ArrayRef<Type> " : ", Type ")
-         << "returnType" << i;
+         << resultName;
+
+      resultNames.emplace_back(std::move(resultName));
+    }
   }
 
   // Emit parameters for all operands
@@ -280,15 +290,15 @@ void OpEmitter::emitStandaloneParamBuilder(bool isAllSameType) {
           numResults - static_cast<int>(hasVariadicResult);
 
       if (numNonVariadicResults > 0) {
-        OUT(4) << "result->addTypes({returnType0";
+        OUT(4) << "result->addTypes({" << resultNames.front();
         for (int i = 1; i < numNonVariadicResults; ++i) {
-          os << ", resultType" << i;
+          os << ", " << resultNames[i];
         }
         os << "});\n";
       }
 
       if (hasVariadicResult) {
-        OUT(4) << formatv("result->addTypes(returnType{0});\n", numResults - 1);
+        OUT(4) << "result->addTypes(" << resultNames.back() << ");\n";
       }
     } else {
       OUT(4) << "result->addTypes({";