Change inferReturnTypes to return LogicalResult and values

Previously the error case was using a sentinel in the error case which was bad. Also make the one `build` invoke the other `build` to reuse verification there.

And follow up on suggestion to use formatv which I missed during previous review.

PiperOrigin-RevId: 284265762

2 files changed, 15 insertions, 12 deletions

diff --git a/mlir/test/lib/TestDialect/TestDialect.cpp b/mlir/test/lib/TestDialect/TestDialect.cpp
index 60a16d968dc..8b9f9a9874a 100644
--- a/mlir/test/lib/TestDialect/TestDialect.cpp
+++ b/mlir/test/lib/TestDialect/TestDialect.cpp
@@ -289,17 +289,17 @@ LogicalResult TestOpWithVariadicResultsAndFolder::fold(
   return success();
 }
 
-SmallVector<Type, 2> mlir::OpWithInferTypeInterfaceOp::inferReturnTypes(
+LogicalResult mlir::OpWithInferTypeInterfaceOp::inferReturnTypes(
     llvm::Optional<Location> location, ArrayRef<Value *> operands,
-    ArrayRef<NamedAttribute> attributes, ArrayRef<Region> regions) {
+    ArrayRef<NamedAttribute> attributes, ArrayRef<Region> regions,
+    SmallVectorImpl<Type> &inferedReturnTypes) {
   if (operands[0]->getType() != operands[1]->getType()) {
-    if (location)
-      mlir::emitError(*location)
-          << "operand type mismatch " << operands[0]->getType() << " vs "
-          << operands[1]->getType();
-    return {nullptr};
+    return emitOptionalError(location, "operand type mismatch ",
+                             operands[0]->getType(), " vs ",
+                             operands[1]->getType());
   }
-  return {operands[0]->getType()};
+  inferedReturnTypes.assign({operands[0]->getType()});
+  return success();
 }
 
 // Static initialization for Test dialect registration.
diff --git a/mlir/test/lib/TestDialect/TestPatterns.cpp b/mlir/test/lib/TestDialect/TestPatterns.cpp
index 7b835c5e61d..06911d2b833 100644
--- a/mlir/test/lib/TestDialect/TestPatterns.cpp
+++ b/mlir/test/lib/TestDialect/TestPatterns.cpp
@@ -74,10 +74,13 @@ struct ReturnTypeOpMatch : public RewritePattern {
                                      PatternRewriter &rewriter) const final {
     if (auto retTypeFn = dyn_cast<InferTypeOpInterface>(op)) {
       SmallVector<Value *, 4> values(op->getOperands());
-      auto res = retTypeFn.inferReturnTypes(op->getLoc(), values,
-                                            op->getAttrs(), op->getRegions());
-      SmallVector<Type, 1> result_types(op->getResultTypes());
-      if (!retTypeFn.isCompatibleReturnTypes(res, result_types))
+      SmallVector<Type, 2> inferedReturnTypes;
+      if (failed(retTypeFn.inferReturnTypes(op->getLoc(), values,
+                                            op->getAttrs(), op->getRegions(),
+                                            inferedReturnTypes)))
+        return matchFailure();
+      SmallVector<Type, 1> resultTypes(op->getResultTypes());
+      if (!retTypeFn.isCompatibleReturnTypes(inferedReturnTypes, resultTypes))
         return op->emitOpError(
                    "inferred type incompatible with return type of operation"),
                matchFailure();