Update debug_util to update index when calling sync

Author: ghpvnist

test/debug_tool/test_pt_xla_debug.py

@@ -177,10 +177,18 @@ def toy_program(t1):
 
     if self.debug_level > 1:
       self.assertEqual(len(executation_causes), 2)
+      self.assertIn(
+          'torch_xla.compile clear the pending graph prior calling the target function',
+          executation_causes[0])
+      self.assertIn('torch_xla.compile\n', executation_causes[1])
     else:
       self.assertEqual(len(executation_causes), 0)
 
     self.assertEqual(len(compilation_causes), 2)
+    self.assertIn(
+        'torch_xla.compile clear the pending graph prior calling the target function',
+        compilation_causes[0])
+    self.assertIn('torch_xla.compile\n', compilation_causes[1])
 
     if self.debug_level > 1:
       # one graph info from compilation, one from execution, hash should match

torch_xla/csrc/debug_util.cpp

@@ -327,24 +327,27 @@ void DebugUtil::analyze_graph_execution_python_frame(
   } else if (frames[0].function == "mark_step" ||
              (frames[0].function == "sync" &&
               endsWith(frames[0].file, "torch_xla.py"))) {
-    if (frames[1].function == "next" &&
-        endsWith(frames[1].file, "parallel_loader.py")) {
+    bool called_by_sync =
+        frames[0].function == "mark_step" && frames[1].function == "sync";
+    int i = called_by_sync ? 2 : 1;
+    if (frames[i].function == "next" &&
+        endsWith(frames[i].file, "parallel_loader.py")) {
       ss << debug_output_prefix
          << "  mark_step in parallel loader at step end\n";
-    } else if (frames[1].function == "__exit__" &&
-               endsWith(frames[1].file, "profiler.py")) {
+    } else if (frames[i].function == "__exit__" &&
+               endsWith(frames[i].file, "profiler.py")) {
       ss << debug_output_prefix
          << "  mark_step when exiting a profiler StepTrace region\n";
-    } else if ((frames[1].function == "extract_compiled_graph_helper" ||
-                frames[1].function == "extract_internal") &&
-               endsWith(frames[1].file, "dynamo_bridge.py")) {
+    } else if ((frames[i].function == "extract_compiled_graph_helper" ||
+                frames[i].function == "extract_internal") &&
+               endsWith(frames[i].file, "dynamo_bridge.py")) {
       ss << debug_output_prefix
          << "  mark_step when dynamo processing input graphs\n";
-    } else if (frames[1].function == "_compile" &&
-               endsWith(frames[1].file, "torch_xla.py")) {
+    } else if (frames[i].function == "_compile" &&
+               endsWith(frames[i].file, "torch_xla.py")) {
       ss << debug_output_prefix << "  torch_xla.compile\n";
-    } else if (frames[1].function == "_clear_pending_ops_before_compile" &&
-               endsWith(frames[1].file, "torch_xla.py")) {
+    } else if (frames[i].function == "_clear_pending_ops_before_compile" &&
+               endsWith(frames[i].file, "torch_xla.py")) {
       ss << debug_output_prefix
          << "  torch_xla.compile clear the pending graph prior calling the "
             "target function\n";