Fix ztensor_slice_dim4 invalid-layout error message

tests/testDriver_slice_dim4_error_message.c

@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+ * Copyright IBM Corp. 2024
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "testsupport.h"
+
+#include <string.h>
+
+/*
+ * Regression coverage for ztensor_slice_dim4() error reporting.
+ *
+ * This test ensures the function reports the *pre-transformed* layout (the
+ * field the switch statement actually uses) when it rejects unsupported slicing
+ * layouts.
+ */
+
+void setUp(void) {
+  log_level = LOGLEVEL_ERROR;
+  log_module[0] = '\0';
+}
+
+void tearDown(void) {}
+
+void test_error_message_reports_pre_transformed_layout(void) {
+  zdnn_tensor_desc pre = {0};
+  zdnn_tensor_desc tfrmd = {0};
+  zdnn_ztensor in = {0};
+
+  // Pick an unsupported pre-transformed layout for slicing.
+  // (Supported: 2DS, 3DS, 4D/NHWC/NCHW)
+  zdnn_init_pre_transformed_desc(ZDNN_1D, FP32, &pre, 2);
+
+  // Transformed descriptor just needs to exist for memcpy in the slicer.
+  init_transformed_desc(ZDNN_NHWC, ZDNN_DLFLOAT16, ZDNN_FORMAT_4DFEATURE, &tfrmd,
+                        2, 1, 1, 1);
+
+  zdnn_init_ztensor(&pre, &tfrmd, &in);
+
+  zdnn_tensor_desc out_pre = {0};
+  zdnn_tensor_desc out_tfrmd = {0};
+  zdnn_ztensor out = {0};
+
+  char buf_stderr[BUFSIZ] = {0};
+
+  stderr_to_pipe();
+  zdnn_status st = ztensor_slice_dim4(&in, 0, 0, &out_pre, &out_tfrmd, &out);
+  restore_stderr(buf_stderr, BUFSIZ);
+
+  TEST_ASSERT_EQUAL_UINT32_MESSAGE(ZDNN_INVALID_LAYOUT, st,
+                                  "Expected invalid layout status");
+
+  // The message should reference the pre-transformed layout we set (ZDNN_1D).
+  TEST_ASSERT_NOT_NULL_MESSAGE(
+      strstr(buf_stderr, "Invalid pre-transformed layout for slicing"),
+      "Expected pre-transformed layout in error message");
+  TEST_ASSERT_NOT_NULL_MESSAGE(strstr(buf_stderr, "ZDNN_1D"),
+                               "Expected ZDNN_1D in error message");
+}
+
+int main(void) {
+  UNITY_BEGIN();
+
+  RUN_TEST(test_error_message_reports_pre_transformed_layout);
+
+  return UNITY_END();
+}

zdnn/tensor_desc.c

@@ -465,8 +465,11 @@ zdnn_status ztensor_slice_dim4(const zdnn_ztensor *input_ztensor,
       output_ztensor->pre_transformed_desc->dim4 = 1;
       break;
     default:
-      return ZDNN_STATUS(ZDNN_INVALID_LAYOUT, "Invalid layout for slicing: %d",
-                         input_ztensor->transformed_desc->layout);
+      return ZDNN_STATUS(ZDNN_INVALID_LAYOUT,
+                         "Invalid pre-transformed layout for slicing: %d (%s)",
+                         input_ztensor->pre_transformed_desc->layout,
+                         get_data_layout_str(
+                             input_ztensor->pre_transformed_desc->layout));
       break;
     }
   }