[OpenMP] libomp: move warnings to after library initialization

[AndreyChurbanov]

Summary

Warnings on deprecated api cannot be suppressed if the library is not initialized.
With this change it is possible to set KMP_WARNINGS=false to suppress the warnings.

[jlpeyton]

LGTM

openmp/runtime/src/kmp_ftn_entry.h

#else
   if (!TCR_4(__kmp_init_middle)) {
     __kmp_middle_initialize();
   }
   return __kmp_avail_proc;
 #endif
 }
 
 void FTN_STDCALL KMP_EXPAND_NAME(FTN_SET_NESTED)(int KMP_DEREF flag) {
-  KMP_INFORM(APIDeprecated, "omp_set_nested", "omp_set_max_active_levels");
 #ifdef KMP_STUB
   __kmps_set_nested(KMP_DEREF flag);
 #else
   kmp_info_t *thread;
   /* For the thread-private internal controls implementation */
   thread = __kmp_entry_thread();
+  KMP_INFORM(APIDeprecated, "omp_set_nested", "omp_set_max_active_levels");
   __kmp_save_internal_controls(thread);
   // Somewhat arbitrarily decide where to get a value for max_active_levels
   int max_active_levels = get__max_active_levels(thread);
   if (max_active_levels == 1)
     max_active_levels = KMP_MAX_ACTIVE_LEVELS_LIMIT;
   set__max_active_levels(thread, (KMP_DEREF flag) ? max_active_levels : 1);
 #endif
 }
 
 int FTN_STDCALL KMP_EXPAND_NAME(FTN_GET_NESTED)(void) {
-  KMP_INFORM(APIDeprecated, "omp_get_nested", "omp_get_max_active_levels");
 #ifdef KMP_STUB
   return __kmps_get_nested();
 #else
   kmp_info_t *thread;
   thread = __kmp_entry_thread();
+  KMP_INFORM(APIDeprecated, "omp_get_nested", "omp_get_max_active_levels");
   return get__max_active_levels(thread) > 1;
 #endif
 }
 
 void FTN_STDCALL KMP_EXPAND_NAME(FTN_SET_DYNAMIC)(int KMP_DEREF flag) {
 #ifdef KMP_STUB
   __kmps_set_dynamic(KMP_DEREF flag ? TRUE : FALSE);
 #else

openmp/runtime/test/api/omp_deprecated.c

+// RUN: %libomp-compile && env KMP_WARNINGS=false %libomp-run 2>&1 | FileCheck %s
+// The test checks that KMP_WARNINGS=false suppresses library warnings
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <omp.h>
+int main(int argc, char** argv) {
+  omp_set_nested(1);
+  if (!omp_get_nested()) {
+    printf("error: omp_set_nested(1) failed\n");
+    return 1;
+  }
+  printf("passed\n");
+  return 0;
+}
+
+// CHECK-NOT: omp_set_nested routine deprecated
+// CHECK-NOT: omp_get_nested routine deprecated