[OpenMP][NFCI] Organize offload entry logic

This moves the offload entry logic into classes and provides convenient
accessors. No functional change intended but we can now print all
offload entries (and later look them up), tested via
`OMPTARGET_DUMP_OFFLOAD_ENTRIES=<device_no>`.

openmp/libomptarget/include/DeviceImage.h

@@ -12,28 +12,39 @@
 #ifndef OMPTARGET_DEVICE_IMAGE_H
 #define OMPTARGET_DEVICE_IMAGE_H
 
+#include "OffloadEntry.h"
 #include "Shared/APITypes.h"
 
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/iterator_range.h"
 #include "llvm/Object/OffloadBinary.h"
 
+#include <memory>
+
 class DeviceImageTy {
 
   std::unique_ptr<llvm::object::OffloadBinary> Binary;
+  llvm::SmallVector<std::unique_ptr<OffloadEntryTy>> OffloadEntries;
 
+  __tgt_bin_desc *BinaryDesc;
   __tgt_device_image Image;
   __tgt_image_info ImageInfo;
 
 public:
-  DeviceImageTy(__tgt_device_image &Image);
+  DeviceImageTy(__tgt_bin_desc &BinaryDesc, __tgt_device_image &Image);
 
   __tgt_device_image &getExecutableImage() { return Image; }
   __tgt_image_info &getImageInfo() { return ImageInfo; }
+  __tgt_bin_desc &getBinaryDesc() { return *BinaryDesc; }
 
   llvm::StringRef
   getArch(llvm::StringRef DefaultArch = llvm::StringRef()) const {
     return ImageInfo.Arch ? ImageInfo.Arch : DefaultArch;
   }
+
+  auto entries() { return llvm::make_pointee_range(OffloadEntries); }
 };
 
 #endif // OMPTARGET_DEVICE_IMAGE_H

openmp/libomptarget/include/OffloadEntry.h

@@ -0,0 +1,48 @@
+//===-- OffloadEntry.h - Representation of offload entries ------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef OMPTARGET_OFFLOAD_ENTRY_H
+#define OMPTARGET_OFFLOAD_ENTRY_H
+
+#include "Shared/APITypes.h"
+
+#include "omptarget.h"
+
+#include "llvm/ADT/StringRef.h"
+
+class DeviceImageTy;
+
+class OffloadEntryTy {
+  DeviceImageTy &DeviceImage;
+  __tgt_offload_entry &OffloadEntry;
+
+public:
+  OffloadEntryTy(DeviceImageTy &DeviceImage, __tgt_offload_entry &OffloadEntry)
+      : DeviceImage(DeviceImage), OffloadEntry(OffloadEntry) {}
+
+  bool isGlobal() const { return getSize() != 0; }
+  size_t getSize() const { return OffloadEntry.size; }
+
+  void *getAddress() const { return OffloadEntry.addr; }
+  llvm::StringRef getName() const { return OffloadEntry.name; }
+  const char *getNameAsCStr() const { return OffloadEntry.name; }
+  __tgt_bin_desc *getBinaryDescription() const;
+
+  bool isCTor() { return hasFlags(OMP_DECLARE_TARGET_CTOR); }
+  bool isDTor() { return hasFlags(OMP_DECLARE_TARGET_DTOR); }
+  bool isLink() { return hasFlags(OMP_DECLARE_TARGET_LINK); }
+
+  bool hasFlags(OpenMPOffloadingDeclareTargetFlags Flags) {
+    return Flags & OffloadEntry.flags;
+  }
+};
+
+#endif // OMPTARGET_OFFLOAD_ENTRY_H

openmp/libomptarget/include/PluginManager.h

@@ -40,6 +40,10 @@ struct PluginAdaptorTy {
   /// Return the number of devices available to this plugin.
   int32_t getNumDevices() const { return NumberOfDevices; }
 
+  /// Add all offload entries described by \p DI to the devices managed by this
+  /// plugin.
+  void addOffloadEntries(DeviceImageTy &DI);
+
   /// RTL index, index is the number of devices of other RTLs that were
   /// registered before, i.e. the OpenMP index of the first device to be
   /// registered with this RTL.
@@ -89,8 +93,8 @@ struct PluginManager {
   /// RTLs identified on the host
   PluginAdaptorManagerTy RTLs;
 
-  void addDeviceImage(__tgt_device_image &TgtDeviceImage) {
-    DeviceImages.emplace_back(std::make_unique<DeviceImageTy>(TgtDeviceImage));
+  void addDeviceImage(__tgt_bin_desc &TgtBinDesc, __tgt_device_image &TgtDeviceImage) {
+    DeviceImages.emplace_back(std::make_unique<DeviceImageTy>(TgtBinDesc, TgtDeviceImage));
   }
 
   /// Iterate over all device images registered with this plugin.

openmp/libomptarget/include/device.h

@@ -19,15 +19,20 @@
 #include <cstring>
 #include <list>
 #include <map>
+#include <memory>
 #include <mutex>
 #include <set>
 
 #include "ExclusiveAccess.h"
+#include "OffloadEntry.h"
 #include "omptarget.h"
 #include "rtl.h"
 
 #include "OpenMP/Mapping.h"
 
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+
 // Forward declarations.
 struct PluginAdaptorTy;
 struct __tgt_bin_desc;
@@ -48,7 +53,7 @@ struct DeviceTy {
 
   bool IsInit;
   std::once_flag InitFlag;
-  bool HasPendingGlobals;
+  bool HasMappedGlobalData = false;
 
   /// Host data to device map type with a wrapper key indirection that allows
   /// concurrent modification of the entries without invalidating the underlying
@@ -223,12 +228,21 @@ struct DeviceTy {
   int32_t destroyEvent(void *Event);
   /// }
 
+  /// Register \p Entry as an offload entry that is avalable on this device.
+  void addOffloadEntry(OffloadEntryTy &Entry);
+
+  /// Print all offload entries to stderr.
+  void dumpOffloadEntries();
+
 private:
   // Call to RTL
   void init(); // To be called only via DeviceTy::initOnce()
 
   /// Deinitialize the device (and plugin).
   void deinit();
+
+  /// All offload entries available on this device.
+  llvm::DenseMap<llvm::StringRef, OffloadEntryTy *> DeviceOffloadEntries;
 };
 
 extern bool deviceIsReady(int DeviceNum);

openmp/libomptarget/src/DeviceImage.cpp

@@ -10,14 +10,27 @@
 
 #include "DeviceImage.h"
 
+#include "OffloadEntry.h"
 #include "Shared/APITypes.h"
 #include "Shared/Debug.h"
 #include "Shared/Utils.h"
 
+#include "llvm/ADT/iterator_range.h"
 #include "llvm/Support/Error.h"
+#include <memory>
+
+__tgt_bin_desc *OffloadEntryTy::getBinaryDescription() const {
+  return &DeviceImage.getBinaryDesc();
+}
+
+DeviceImageTy::DeviceImageTy(__tgt_bin_desc &BinaryDesc,
+                             __tgt_device_image &TgtDeviceImage)
+    : BinaryDesc(&BinaryDesc), Image(TgtDeviceImage) {
+
+  for (__tgt_offload_entry &Entry :
+       llvm::make_range(Image.EntriesBegin, Image.EntriesEnd))
+    OffloadEntries.emplace_back(std::make_unique<OffloadEntryTy>(*this, Entry));
 
-DeviceImageTy::DeviceImageTy(__tgt_device_image &TgtDeviceImage)
-    : Image(TgtDeviceImage) {
   llvm::StringRef ImageStr(
       static_cast<char *>(Image.ImageStart),
       llvm::omp::target::getPtrDiff(Image.ImageEnd, Image.ImageStart));

openmp/libomptarget/src/PluginManager.cpp

@@ -69,6 +69,14 @@ PluginAdaptorTy::PluginAdaptorTy(const std::string &Name) : Name(Name) {
   DP("Registered '%s' with %d devices!\n", Name.c_str(), NumberOfDevices);
 }
 
+void PluginAdaptorTy::addOffloadEntries(DeviceImageTy &DI) {
+  for (int32_t I = 0; I < NumberOfDevices; ++I) {
+    DeviceTy &Device = *PM->Devices[DeviceOffset + I];
+    for (OffloadEntryTy &Entry : DI.entries())
+      Device.addOffloadEntry(Entry);
+  }
+}
+
 void PluginManager::init() {
   DP("Loading RTLs...\n");
 

openmp/libomptarget/src/device.cpp

@@ -11,9 +11,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "device.h"
+#include "OffloadEntry.h"
 #include "OpenMP/OMPT/Callback.h"
 #include "OpenMP/OMPT/Interface.h"
 #include "PluginManager.h"
+#include "Shared/APITypes.h"
+#include "Shared/Debug.h"
 #include "omptarget.h"
 #include "private.h"
 #include "rtl.h"
@@ -61,7 +64,7 @@ int HostDataToTargetTy::addEventIfNecessary(DeviceTy &Device,
 
 DeviceTy::DeviceTy(PluginAdaptorTy *RTL)
     : DeviceID(-1), RTL(RTL), RTLDeviceID(-1), IsInit(false), InitFlag(),
-      HasPendingGlobals(false), PendingCtorsDtors(), PendingGlobalsMtx() {}
+      PendingCtorsDtors(), PendingGlobalsMtx() {}
 
 DeviceTy::~DeviceTy() {
   if (DeviceID == -1 || !(getInfoLevel() & OMP_INFOTYPE_DUMP_TABLE))
@@ -807,3 +810,52 @@ bool deviceIsReady(int DeviceNum) {
 
   return true;
 }
+
+void DeviceTy::addOffloadEntry(OffloadEntryTy &Entry) {
+  std::lock_guard<decltype(PendingGlobalsMtx)> Lock(PendingGlobalsMtx);
+  DeviceOffloadEntries[Entry.getName()] = &Entry;
+  if (Entry.isGlobal())
+    return;
+
+  if (Entry.isCTor()) {
+    DP("Adding ctor " DPxMOD " to the pending list.\n",
+       DPxPTR(Entry.getAddress()));
+    MESSAGE("WARNING: Calling deprecated constructor for entry %s will be "
+            "removed in a future release \n",
+            Entry.getNameAsCStr());
+    PendingCtorsDtors[Entry.getBinaryDescription()].PendingCtors.push_back(
+        Entry.getAddress());
+  } else if (Entry.isDTor()) {
+    // Dtors are pushed in reverse order so they are executed from end
+    // to beginning when unregistering the library!
+    DP("Adding dtor " DPxMOD " to the pending list.\n",
+       DPxPTR(Entry.getAddress()));
+    MESSAGE("WARNING: Calling deprecated destructor for entry %s will be "
+            "removed in a future release \n",
+            Entry.getNameAsCStr());
+    PendingCtorsDtors[Entry.getBinaryDescription()].PendingDtors.push_front(
+        Entry.getAddress());
+  }
+
+  if (Entry.isLink()) {
+    MESSAGE(
+        "WARNING: The \"link\" attribute is not yet supported for entry: %s!\n",
+        Entry.getNameAsCStr());
+  }
+}
+
+void DeviceTy::dumpOffloadEntries() {
+  fprintf(stderr, "Device %i offload entries:\n", DeviceID);
+  for (auto &It : DeviceOffloadEntries) {
+    const char *Kind = "kernel";
+    if (It.second->isCTor())
+      Kind = "constructor";
+    else if (It.second->isDTor())
+      Kind = "destructor";
+    else if (It.second->isLink())
+      Kind = "link";
+    else if (It.second->isGlobal())
+      Kind = "global var.";
+    fprintf(stderr, "  %11s: %s\n", Kind, It.second->getNameAsCStr());
+  }
+}

openmp/libomptarget/src/omptarget.cpp

@@ -16,6 +16,7 @@
 #include "OpenMP/OMPT/Callback.h"
 #include "OpenMP/OMPT/Interface.h"
 #include "PluginManager.h"
+#include "Shared/EnvironmentVar.h"
 #include "device.h"
 #include "private.h"
 #include "rtl.h"
@@ -128,6 +129,9 @@ static uint64_t getPartialStructRequiredAlignment(void *HstPtrBase) {
 
 /// Map global data and execute pending ctors
 static int initLibrary(DeviceTy &Device) {
+  if (Device.HasMappedGlobalData)
+    return OFFLOAD_SUCCESS;
+
   /*
    * Map global data
    */
@@ -276,7 +280,12 @@ static int initLibrary(DeviceTy &Device) {
     if (AsyncInfo.synchronize() != OFFLOAD_SUCCESS)
       return OFFLOAD_FAIL;
   }
-  Device.HasPendingGlobals = false;
+  Device.HasMappedGlobalData = true;
+
+  static Int32Envar DumpOffloadEntries =
+      Int32Envar("OMPTARGET_DUMP_OFFLOAD_ENTRIES", -1);
+  if (DumpOffloadEntries.get() == DeviceId)
+    Device.dumpOffloadEntries();
 
   return OFFLOAD_SUCCESS;
 }
@@ -374,7 +383,7 @@ bool checkDeviceAndCtors(int64_t &DeviceID, ident_t *Loc) {
   {
     std::lock_guard<decltype(Device.PendingGlobalsMtx)> LG(
         Device.PendingGlobalsMtx);
-    if (Device.HasPendingGlobals && initLibrary(Device) != OFFLOAD_SUCCESS) {
+    if (initLibrary(Device) != OFFLOAD_SUCCESS) {
       REPORT("Failed to init globals on device %" PRId64 "\n", DeviceID);
       handleTargetOutcome(false, Loc);
       return true;