[mlir][linalg] Fix crashes in parser on linalg ops without operands

`parseDstStyleOp` parses both `ins()` and `outs()` optionally. The parsers
for `linalg.transpose`, `linalg.broadcast` and `linalg.map` however
assume that at least one operand is present in the state, leading to crashes
otherwise.

This patch adds checks to the parsers which stop them from crashing if
no operands were parsed. After the Ops are parsed successfuly, the verifier
takes it from there.

Fix llvm#97857

mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp

@@ -1356,8 +1356,10 @@ ParseResult MapOp::parse(OpAsmParser &parser, OperationState &result) {
     return failure();
 
   if (payloadOpName.has_value()) {
-    addBodyWithPayloadOp(parser, result, payloadOpName.value(), payloadOpAttrs,
-                         ArrayRef(result.operands).drop_back());
+    if (!result.operands.empty())
+      addBodyWithPayloadOp(parser, result, payloadOpName.value(),
+                           payloadOpAttrs,
+                           ArrayRef(result.operands).drop_back());
   } else {
     SmallVector<OpAsmParser::Argument> regionArgs;
     if (parser.parseArgumentList(regionArgs, OpAsmParser::Delimiter::Paren,
@@ -1739,7 +1741,8 @@ static void buildIdentityRegion(OpBuilder &builder, Location loc,
                                 ValueRange outputs) {
   buildGenericRegion(builder, loc, region, inputs, outputs,
                      [](OpBuilder &b, Location loc, ValueRange args) {
-                       b.create<linalg::YieldOp>(loc, args[0]);
+                       if (!args.empty())
+                         b.create<linalg::YieldOp>(loc, args[0]);
                      });
 }
 

mlir/test/Dialect/Linalg/invalid.mlir

@@ -455,6 +455,18 @@ func.func @map_input_output_shape_mismatch(
 
 // -----
 
+func.func @map_no_operands(
+    %lhs: tensor<64xf32>, %rhs: tensor<64xf32>, %init: tensor<64xf32>)
+    -> tensor<64xf32> {
+  // This must not crash the parser.
+  linalg.map { arith.addf }
+  // expected-error @+1 {{cannot name an operation with no results}}
+  %add = linalg.map { arith.addf }
+  func.return %add : tensor<64xf32>
+}
+
+// -----
+
 func.func @reduce_input_vs_init_dimension_mismatch(
     %input: tensor<16x32x64xf32>,
     %init: tensor<16x64xf32>)  -> tensor<16x64xf32> {
@@ -676,6 +688,16 @@ func.func @transpose_input_init_rank_mismatch(%input: tensor<16x32xf32>,
 
 // -----
 
+func.func @transpose_no_operands() -> tensor<32x64x16xf32> {
+  // This must not crash the parser.
+  linalg.transpose permutation = [1, 0, 2]
+  // expected-error @+1 {{cannot name an operation with no results}}
+  %transpose = linalg.transpose permutation = [1, 0, 2]
+  func.return %transpose : tensor<32x64x16xf32>
+}
+
+// -----
+
 func.func @broadcast_input_dims_rank_mismatch(
     %input: tensor<4x16xf32>, %init: tensor<4x8x16xf32>)
     -> tensor<4x8x16xf32> {
@@ -725,6 +747,15 @@ func.func @broadcast_size_1_extension_not_supported(
       dimensions = [1]
   func.return %bcast : tensor<4x?x16xf32>
 }
+// -----
+
+func.func @broadcast_no_operands()
+    -> tensor<4x?x16xf32> {
+  linalg.broadcast dimensions = [1]
+  // expected-error @+1 {{cannot name an operation with no results}}
+  %broadcast = linalg.broadcast dimensions = [1]
+  func.return %broadcast : tensor<32x64x16xf32>
+}
 
 // -----