[OpenMP][OMPT][GOMP] task frame support in KMP_API_NAME_GOMP_PARALLEL_SECTIONS

KMP_API_NAME_GOMP_PARALLEL_SECTIONS function was missing the task frame support.
This patch introduced a fix responsible to set properly the exit_frame of
the innermost implicit task that corresponds to the parallel section construct,
as well as the enter_frame of the task that encloses the mentioned implicit task.

This patch also introduced a simple test case sections_serialized.c that contains
serialized parallel section construct and validates whether the mentioned
task frames are set correctly.

Differential Revision: https://reviews.llvm.org/D112205

Author: vladaindjic

openmp/runtime/src/kmp_gsupport.cpp

@@ -1522,6 +1522,13 @@ void KMP_EXPAND_NAME(KMP_API_NAME_GOMP_PARALLEL_SECTIONS)(void (*task)(void *),
   KA_TRACE(20, ("GOMP_parallel_sections: T#%d\n", gtid));
 
 #if OMPT_SUPPORT
+  ompt_frame_t *task_frame;
+  kmp_info_t *thr;
+  if (ompt_enabled.enabled) {
+    thr = __kmp_threads[gtid];
+    task_frame = &(thr->th.th_current_task->ompt_task_info.frame);
+    task_frame->enter_frame.ptr = OMPT_GET_FRAME_ADDRESS(0);
+  }
   OMPT_STORE_RETURN_ADDRESS(gtid);
 #endif
 
@@ -1537,9 +1544,31 @@ void KMP_EXPAND_NAME(KMP_API_NAME_GOMP_PARALLEL_SECTIONS)(void (*task)(void *),
 
     KMP_DISPATCH_INIT(&loc, gtid, kmp_nm_dynamic_chunked, 1, count, 1, 1, TRUE);
   }
+
+#if OMPT_SUPPORT
+  ompt_frame_t *child_frame;
+  if (ompt_enabled.enabled) {
+    child_frame = &(thr->th.th_current_task->ompt_task_info.frame);
+    child_frame->exit_frame.ptr = OMPT_GET_FRAME_ADDRESS(0);
+  }
+#endif
+
   task(data);
+
+#if OMPT_SUPPORT
+  if (ompt_enabled.enabled) {
+    child_frame->exit_frame = ompt_data_none;
+  }
+#endif
+
   KMP_EXPAND_NAME(KMP_API_NAME_GOMP_PARALLEL_END)();
   KA_TRACE(20, ("GOMP_parallel_sections exit: T#%d\n", gtid));
+
+#if OMPT_SUPPORT
+  if (ompt_enabled.enabled) {
+    task_frame->enter_frame = ompt_data_none;
+  }
+#endif
 }
 
 #define PARALLEL_LOOP(func, schedule, ompt_pre, ompt_post)                     \

openmp/runtime/test/ompt/worksharing/taskinfo/sections_serialized.c

@@ -0,0 +1,48 @@
+// RUN: %libomp-compile-and-run | %sort-threads | FileCheck %s
+// REQUIRES: ompt
+
+#include "callback.h"
+#include <omp.h>
+
+int main()
+{
+#pragma omp parallel sections num_threads(1)
+  {
+#pragma omp section
+    {
+      // implicit task info
+      print_ids(0);
+      // initial task info
+      print_ids(1);
+    }
+  }
+
+  // Check if libomp supports the callbacks for this test.
+  // CHECK-NOT: {{^}}0: Could not register callback 'ompt_callback_task_create'
+  // CHECK-NOT: {{^}}0: Could not register callback 'ompt_callback_implicit_task'
+
+
+  // CHECK: {{^}}0: NULL_POINTER=[[NULL:.*$]]
+  // CHECK: {{^}}[[MASTER_ID:[0-9]+]]: ompt_event_initial_task_begin: parallel_id=[[INITIAL_PARALLEL_ID:[0-9]+]], task_id=[[INITIAL_TASK_ID:[0-9]+]], actual_parallelism=1, index=1, flags=1
+
+  // region 0
+  // CHECK: {{^}}[[MASTER_ID:[0-9]+]]: ompt_event_parallel_begin
+  // CHECK-SAME: parent_task_frame.exit=[[NULL]], parent_task_frame.reenter=[[INITIAL_TASK_FRAME_ENTER:0x[0-f]+]],
+  // CHECK-SAME: parallel_id=[[PARALLEL_ID:[0-9]+]]
+
+  // CHECK: {{^}}[[MASTER_ID]]: ompt_event_implicit_task_begin: parallel_id=[[PARALLEL_ID]], task_id=[[TASK_ID:[0-9]+]]
+
+  // information about implicit task (exit frame should be set, while enter should be NULL)
+  // CHECK: {{^}}[[MASTER_ID]]: task level 0: parallel_id=[[PARALLEL_ID]], task_id=[[TASK_ID]]
+  // CHECK-SAME: exit_frame={{0x[0-f]+}}
+  // CHECK-SAME: reenter_frame=[[NULL]]
+  // CHECK-SAME: task_type=ompt_task_implicit
+
+  // information about initial task (exit frame should be NULL, while enter frame shoule be set)
+  // CHECK: {{^}}[[MASTER_ID]]: task level 1: parallel_id=[[INITIAL_PARALLEL_ID]], task_id=[[INITIAL_TASK_ID]]
+  // CHECK-SAME: exit_frame=[[NULL]]
+  // CHECK-SAME: reenter_frame=[[INITIAL_TASK_FRAME_ENTER]]
+  // CHECK-SAME: task_type=ompt_task_initial
+
+  return 0;
+}