[llvm] [openmp] [OFFLOAD][OPENMP] 6.0 compatible interop interface (PR #143491)

[Kevin Sala Penades via llvm-commits]

================
@@ -193,119 +194,276 @@ __OMP_GET_INTEROP_TY3(const char *, type_desc)
 __OMP_GET_INTEROP_TY3(const char *, rc_desc)
 #undef __OMP_GET_INTEROP_TY3
 
-static const char *copyErrorString(llvm::Error &&Err) {
-  // TODO: Use the error string while avoiding leaks.
-  std::string ErrMsg = llvm::toString(std::move(Err));
-  char *UsrMsg = reinterpret_cast<char *>(malloc(ErrMsg.size() + 1));
-  strcpy(UsrMsg, ErrMsg.c_str());
-  return UsrMsg;
-}
-
 extern "C" {
 
-void __tgt_interop_init(ident_t *LocRef, int32_t Gtid,
-                        omp_interop_val_t *&InteropPtr,
-                        kmp_interop_type_t InteropType, int32_t DeviceId,
-                        int32_t Ndeps, kmp_depend_info_t *DepList,
-                        int32_t HaveNowait) {
-  int32_t NdepsNoalias = 0;
-  kmp_depend_info_t *NoaliasDepList = NULL;
-  assert(InteropType != kmp_interop_type_unknown &&
-         "Cannot initialize with unknown interop_type!");
-  if (DeviceId == -1) {
-    DeviceId = omp_get_default_device();
+omp_interop_val_t *__tgt_interop_get(ident_t *LocRef, int32_t InteropType,
+                                     int64_t DeviceNum, int32_t NumPrefers,
+                                     interop_spec_t *Prefers,
+                                     interop_ctx_t *Ctx, dep_pack_t *Deps) {
+
+  DP("Call to %s with device_num %" PRId64 ", interop type %" PRId32
+     ", number of preferred specs %" PRId32 "%s%s\n",
+     __func__, DeviceNum, InteropType, NumPrefers,
+     Ctx->flags.implicit ? " (implicit)" : "",
+     Ctx->flags.nowait ? " (nowait)" : "");
+
+  if (OffloadPolicy::get(*PM).Kind == OffloadPolicy::DISABLED)
+    return omp_interop_none;
+
+  // Now, try to create an interop with device_num.
+  if (DeviceNum == OFFLOAD_DEVICE_DEFAULT)
+    DeviceNum = omp_get_default_device();
+
+  auto gtid = Ctx->gtid;
+
+  if (InteropType == kmp_interop_type_targetsync) {
+    if (Ctx->flags.nowait)
+      DP("Warning: nowait flag on interop creation not supported yet. "
+         "Ignored\n");
+    if (Deps)
+      __kmpc_omp_wait_deps(LocRef, gtid, Deps->ndeps, Deps->deplist,
+                           Deps->ndeps_noalias, Deps->noalias_deplist);
   }
 
-  if (InteropType == kmp_interop_type_tasksync) {
-    __kmpc_omp_wait_deps(LocRef, Gtid, Ndeps, DepList, NdepsNoalias,
-                         NoaliasDepList);
+  auto DeviceOrErr = PM->getDevice(DeviceNum);
+  if (!DeviceOrErr) {
+    [[maybe_unused]] std::string ErrStr = toString(DeviceOrErr.takeError());
+    DP("Couldn't find device %" PRId64
+       " while constructing interop object: %s\n",
+       DeviceNum, ErrStr.c_str());
----------------
kevinsala wrote:

```
toString(DeviceOrErr.takeError()).c_str()
```

https://github.com/llvm/llvm-project/pull/143491