[mlir][openacc] Update verifier to catch missing device type attribute (#111586)

Operands with device_type support need the corresponding attribute but
this was not catches in the verifier if it was missing. The custom
parser usually constructs it but creating the op from python could lead
to a segfault in the printer. This patch updates the verifier so we
catch this early on.

Author: clementval

mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp

@@ -759,20 +759,23 @@ static LogicalResult verifyDeviceTypeAndSegmentCountMatch(
     Op op, OperandRange operands, DenseI32ArrayAttr segments,
     ArrayAttr deviceTypes, llvm::StringRef keyword, int32_t maxInSegment = 0) {
   std::size_t numOperandsInSegments = 0;
-
-  if (!segments)
-    return success();
-
-  for (auto segCount : segments.asArrayRef()) {
-    if (maxInSegment != 0 && segCount > maxInSegment)
-      return op.emitOpError() << keyword << " expects a maximum of "
-                              << maxInSegment << " values per segment";
-    numOperandsInSegments += segCount;
+  std::size_t nbOfSegments = 0;
+
+  if (segments) {
+    for (auto segCount : segments.asArrayRef()) {
+      if (maxInSegment != 0 && segCount > maxInSegment)
+        return op.emitOpError() << keyword << " expects a maximum of "
+                                << maxInSegment << " values per segment";
+      numOperandsInSegments += segCount;
+      ++nbOfSegments;
+    }
   }
-  if (numOperandsInSegments != operands.size())
+
+  if ((numOperandsInSegments != operands.size()) ||
+      (!deviceTypes && !operands.empty()))
     return op.emitOpError()
            << keyword << " operand count does not match count in segments";
-  if (deviceTypes.getValue().size() != (size_t)segments.size())
+  if (deviceTypes && deviceTypes.getValue().size() != nbOfSegments)
     return op.emitOpError()
            << keyword << " segment count does not match device_type count";
   return success();

mlir/test/Dialect/OpenACC/invalid.mlir

@@ -507,6 +507,13 @@ acc.parallel num_gangs({%i64value: i64, %i64value : i64, %i64value : i64, %i64va
 
 // -----
 
+%0 = "arith.constant"() <{value = 1 : i64}> : () -> i64
+// expected-error@+1 {{num_gangs operand count does not match count in segments}}
+"acc.parallel"(%0) <{numGangsSegments = array<i32: 1>, operandSegmentSizes = array<i32: 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0>}> ({
+}) : (i64) -> ()
+
+// -----
+
 %i64value = arith.constant 1 : i64
 acc.parallel {
 // expected-error@+1 {{'acc.set' op cannot be nested in a compute operation}}