[Libomptarget] Register OpenMP requires flags using the new interface

[jhuber6]

Summary

A previous patch changed how we perform the generation of omp requires
flags. This patch adds the necessary support to the runtime and removes
the old interface.

Depends on D133539

openmp/libomptarget/include/omptarget.h

 
 /// This struct is a record of all the host code that may be offloaded to a
 /// target.
 struct __tgt_bin_desc {
   int32_t NumDeviceImages;           // Number of device types supported
   __tgt_device_image *DeviceImages;  // Array of device images (1 per dev. type)
   __tgt_offload_entry *HostEntriesBegin; // Begin of table with all host entries
   __tgt_offload_entry *HostEntriesEnd;   // End of table (non inclusive)
+  int64_t *RegisterRequiresBegin; // Begin of requires flag array.
+  int64_t *RegisterRequiresEnd;   // End of requires flag array.
 };
 
 /// This struct contains the offload entries identified by the target runtime
 struct __tgt_target_table {
   __tgt_offload_entry *EntriesBegin; // Begin of the table with all the entries
   __tgt_offload_entry
       *EntriesEnd; // End of the table with all the entries (non inclusive)
 };

openmp/libomptarget/src/LegacyAPI.cpp

EXTERN void __kmpc_push_target_tripcount_mapper(ident_t *Loc, int64_t DeviceId,
   TIMESCOPE_WITH_IDENT(Loc);
   DP("WARNING: __kmpc_push_target_tripcount has been deprecated and is a noop");
 }
 
 EXTERN void __kmpc_push_target_tripcount(int64_t DeviceId,
                                          uint64_t LoopTripcount) {
   __kmpc_push_target_tripcount_mapper(nullptr, DeviceId, LoopTripcount);
 }
+
+EXTERN void __tgt_register_requires(int64_t Flags) {
+  DP("__tgt_register_requires has been deprecated");
+}

openmp/libomptarget/src/interface.cpp

 #include "rtl.h"
 
 #include <cassert>
 #include <cstdio>
 #include <cstdlib>
 #include <mutex>
 
 ////////////////////////////////////////////////////////////////////////////////
-/// adds requires flags
-EXTERN void __tgt_register_requires(int64_t Flags) {
-  TIMESCOPE();
-  PM->RTLs.registerRequires(Flags);
-}
-
-////////////////////////////////////////////////////////////////////////////////
 /// adds a target shared library to the target execution image
 EXTERN void __tgt_register_lib(__tgt_bin_desc *Desc) {
   TIMESCOPE();
   std::call_once(PM->RTLs.InitFlag, &RTLsTy::loadRTLs, &PM->RTLs);
   for (auto &RTL : PM->RTLs.AllRTLs) {
     if (RTL.register_lib) {
       if ((*RTL.register_lib)(Desc) != OFFLOAD_SUCCESS) {
         DP("Could not register library with %s", RTL.RTLName.c_str());

openmp/libomptarget/src/rtl.cpp

 void RTLsTy::initAllRTLs() {
   for (auto &R : AllRTLs)
     initRTLonce(R);
 }
 
 void RTLsTy::registerLib(__tgt_bin_desc *Desc) {
   PM->RTLsMtx.lock();
 
+  for (int64_t *RequiresB = Desc->RegisterRequiresBegin,
+               *RequiresE = Desc->RegisterRequiresEnd;
+       RequiresB != RequiresE; ++RequiresB) {
+    if (*RequiresB != OMP_REQ_UNDEFINED)
+      registerRequires(*RequiresB);
+  }
+
   // Extract the exectuable image and extra information if availible.
   for (int32_t i = 0; i < Desc->NumDeviceImages; ++i)
     PM->Images.emplace_back(getExecutableImage(&Desc->DeviceImages[i]),
                             getImageInfo(&Desc->DeviceImages[i]));
 
   // Register the images with the RTLs that understand them, if any.
   for (auto &ImageAndInfo : PM->Images) {
     // Obtain the image and information that was previously extracted.