[clang] [llvm] [Offload] Provide a kernel library useable by the offload runtime (PR #104168)

[Jan Patrick Lehr via cfe-commits]

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@@ -1533,6 +1565,67 @@ Error GenericDeviceTy::printInfo() {
   return Plugin::success();
 }
 
+Expected<GenericKernelTy *> GenericDeviceTy::getKernel(llvm::StringRef Name,
+                                                       DeviceImageTy *ImagePtr,
+                                                       bool Optional) {
+  bool KernelFound = false;
+  GenericKernelTy *&KernelPtr = KernelMap[Name];
+  if (!KernelPtr) {
+    GenericGlobalHandlerTy &GHandler = Plugin.getGlobalHandler();
+
+    auto CheckImage = [&](DeviceImageTy &Image) -> GenericKernelTy * {
+      if (!GHandler.isSymbolInImage(*this, Image, Name))
+        return nullptr;
+      KernelFound = true;
+
+      auto KernelOrErr = constructKernelImpl(Name);
+      if (Error Err = KernelOrErr.takeError()) {
+        [[maybe_unused]] std::string ErrStr = toString(std::move(Err));
+        DP("Failed to construct kernel ('%s'): %s", Name.data(),
+           ErrStr.c_str());
+        return nullptr;
+      }
+
+      GenericKernelTy &Kernel = *KernelOrErr;
+      if (auto Err = Kernel.init(*this, Image)) {
+        [[maybe_unused]] std::string ErrStr = toString(std::move(Err));
+        DP("Failed to initialize kernel ('%s'): %s", Name.data(),
+           ErrStr.c_str());
+        return nullptr;
+      }
+
+      return &Kernel;
+    };
+
+    if (ImagePtr) {
+      KernelPtr = CheckImage(*ImagePtr);
+    } else {
+      for (DeviceImageTy *Image : LoadedImages) {
+        KernelPtr = CheckImage(*Image);
+        if (KernelPtr)
+          break;
+      }
+    }
+  }
+
+  // If we didn't find the kernel and it was optional, we do not emit an error.
+  if (!KernelPtr && !KernelFound && Optional)
+    return nullptr;
+  // If we didn't find the kernel and it was not optional, we will emit an
+  // error.
+  if (!KernelPtr && !KernelFound)
+    return Plugin::error(
+        "Kernel '%s' not found%s", Name.data(),
+        ImagePtr
+            ? ""
+            : ", searched " + std::to_string(LoadedImages.size()) + " images");
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jplehr wrote:

I believe this misses a `.data()` or something.

https://github.com/llvm/llvm-project/pull/104168