[clang] [clang-repl] Implement IncrementalHIPDeviceParser for HIP device compilation (PR #218337)

Aditya Sinha via cfe-commits cfe-commits at lists.llvm.org
Thu Sep 10 04:03:28 PDT 2026


https://github.com/AdityaSinha149 updated https://github.com/llvm/llvm-project/pull/218337

>From fc929d677fa03df69124c24d86a138ecf3826e4d Mon Sep 17 00:00:00 2001
From: AdityaSinha149 <adsinha at amd.com>
Date: Mon, 24 Aug 2026 12:58:31 +0530
Subject: [PATCH] [clang-repl] Made IncrementalHipDeviceParser class

---
 clang/include/clang/CodeGen/CodeGenAction.h |   5 +
 clang/lib/CodeGen/BackendConsumer.h         |   8 +
 clang/lib/CodeGen/CodeGenAction.cpp         |   9 +
 clang/lib/Interpreter/DeviceOffload.cpp     | 205 ++++++++++++++++++--
 clang/lib/Interpreter/DeviceOffload.h       |  38 +++-
 5 files changed, 247 insertions(+), 18 deletions(-)

diff --git a/clang/include/clang/CodeGen/CodeGenAction.h b/clang/include/clang/CodeGen/CodeGenAction.h
index 84fa4549d5033..319cc8f2b14a1 100644
--- a/clang/include/clang/CodeGen/CodeGenAction.h
+++ b/clang/include/clang/CodeGen/CodeGenAction.h
@@ -63,6 +63,11 @@ class CodeGenAction : public ASTFrontendAction {
 
   CodeGenerator *getCodeGenerator() const;
 
+  /// Reload the -mlink-builtin-bitcode modules into the backend consumer.
+  /// LinkInModules() consumes them, so incremental compilation must reload them
+  /// before each translation unit (e.g. to re-link HIP device libraries).
+  void reloadLinkModules(CompilerInstance &CI);
+
   BackendConsumer *BEConsumer = nullptr;
 };
 
diff --git a/clang/lib/CodeGen/BackendConsumer.h b/clang/lib/CodeGen/BackendConsumer.h
index 708658d206baf..d6d713844a195 100644
--- a/clang/lib/CodeGen/BackendConsumer.h
+++ b/clang/lib/CodeGen/BackendConsumer.h
@@ -92,6 +92,14 @@ class BackendConsumer : public ASTConsumer {
   // Links each entry in LinkModules into our module.  Returns true on error.
   bool LinkInModules(llvm::Module *M);
 
+  /// Replace the set of modules to link in. LinkInModules() consumes the
+  /// modules, so incremental compilation (clang-repl) must reload and reseed
+  /// them before each translation unit; otherwise later inputs would miss the
+  /// linked-in bitcode (e.g. HIP device libraries).
+  void setLinkModules(SmallVector<LinkModule, 4> LMs) {
+    LinkModules = std::move(LMs);
+  }
+
   /// Get the best possible source location to represent a diagnostic that
   /// may have associated debug info.
   const FullSourceLoc getBestLocationFromDebugLoc(
diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index 6911cab379fdc..c8b4b9de48983 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -984,6 +984,15 @@ CodeGenerator *CodeGenAction::getCodeGenerator() const {
   return BEConsumer->getCodeGenerator();
 }
 
+void CodeGenAction::reloadLinkModules(CompilerInstance &CI) {
+  if (!BEConsumer)
+    return;
+  SmallVector<LinkModule, 4> LMs;
+  if (clang::loadLinkModules(CI, *VMContext, LMs))
+    return;
+  BEConsumer->setLinkModules(std::move(LMs));
+}
+
 bool CodeGenAction::BeginSourceFileAction(CompilerInstance &CI) {
   if (CI.getFrontendOpts().GenReducedBMI)
     CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
diff --git a/clang/lib/Interpreter/DeviceOffload.cpp b/clang/lib/Interpreter/DeviceOffload.cpp
index 38cecd142a8e6..bfa733585b2a9 100644
--- a/clang/lib/Interpreter/DeviceOffload.cpp
+++ b/clang/lib/Interpreter/DeviceOffload.cpp
@@ -6,24 +6,205 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements offloading to CUDA devices.
+// This file implements offloading to HIP and CUDA devices.
 //
 //===----------------------------------------------------------------------===//
 
 #include "DeviceOffload.h"
+#include "IncrementalAction.h"
 
 #include "clang/Basic/TargetOptions.h"
+#include "clang/CodeGen/BackendUtil.h"
+#include "clang/CodeGen/CodeGenAction.h"
 #include "clang/CodeGen/ModuleBuilder.h"
+#include "clang/Driver/OffloadBundler.h"
 #include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendAction.h"
 #include "clang/Interpreter/PartialTranslationUnit.h"
 
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/MC/TargetRegistry.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FileUtilities.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Program.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/TargetParser/Host.h"
+#include "llvm/Transforms/IPO/Internalize.h"
 
 namespace clang {
 
+static llvm::Expected<llvm::TargetMachine *>
+getOrCreateTargetMachine(std::unique_ptr<llvm::TargetMachine> &Cache,
+                         llvm::Module &M, llvm::StringRef CPU) {
+  if (!Cache) {
+    std::string Error;
+    const llvm::Target *Target =
+        llvm::TargetRegistry::lookupTarget(M.getTargetTriple(), Error);
+    if (!Target)
+      return llvm::make_error<llvm::StringError>(std::move(Error),
+                                                 std::error_code());
+    llvm::TargetOptions TO = llvm::TargetOptions();
+    Cache.reset(Target->createTargetMachine(M.getTargetTriple(), CPU, "", TO,
+                                            llvm::Reloc::Model::PIC_));
+  }
+  M.setDataLayout(Cache->createDataLayout());
+  return Cache.get();
+}
+
+IncrementalHIPDeviceParser::IncrementalHIPDeviceParser(
+    CompilerInstance &DeviceInstance, CompilerInstance &HostInstance,
+    IncrementalAction *DeviceAct,
+    llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> FS,
+    llvm::Error &Err, std::list<PartialTranslationUnit> &PTUs)
+    : IncrementalParser(DeviceInstance, DeviceAct, Err, PTUs),
+      DeviceCI(DeviceInstance), VFS(FS),
+      CodeGenOpts(HostInstance.getCodeGenOpts()),
+      DeviceCodeGenOpts(DeviceInstance.getCodeGenOpts()),
+      TargetOpts(DeviceInstance.getTargetOpts()) {
+  if (Err)
+    return;
+  StringRef Arch = TargetOpts.CPU;
+  if (!Arch.starts_with("gfx")) {
+    Err = llvm::joinErrors(std::move(Err), llvm::make_error<llvm::StringError>(
+                                               "Invalid HIP architecture",
+                                               llvm::inconvertibleErrorCode()));
+    return;
+  }
+}
+
+llvm::Expected<TranslationUnitDecl *>
+IncrementalHIPDeviceParser::Parse(llvm::StringRef Input) {
+  if (FrontendAction *WrappedAct = Act->getWrapped())
+    if (WrappedAct->hasIRSupport())
+      static_cast<CodeGenAction *>(WrappedAct)->reloadLinkModules(DeviceCI);
+
+  return IncrementalParser::Parse(Input);
+}
+
+llvm::Expected<llvm::StringRef> IncrementalHIPDeviceParser::GenerateHSACO() {
+  auto &PTU = PTUs.back();
+
+  llvm::SmallVector<char, 0> Object;
+  auto ObjOS = std::make_unique<llvm::raw_svector_ostream>(Object);
+  clang::emitBackendOutput(
+      DeviceCI, DeviceCI.getCodeGenOpts(),
+      DeviceCI.getTarget().getDataLayoutString(), PTU.TheModule.get(),
+      Backend_EmitObj, DeviceCI.getVirtualFileSystemPtr(), std::move(ObjOS));
+
+  std::string Exe = llvm::sys::fs::getMainExecutable(nullptr, nullptr);
+  llvm::StringRef ExeDir = llvm::sys::path::parent_path(Exe);
+  llvm::ErrorOr<std::string> LLDPath =
+      llvm::sys::findProgramByName("ld.lld", {ExeDir});
+  if (!LLDPath)
+    LLDPath = llvm::sys::findProgramByName("ld.lld");
+  if (!LLDPath)
+    return llvm::make_error<llvm::StringError>(
+        "Could not find ld.lld next to the executable or on PATH.",
+        llvm::inconvertibleErrorCode());
+
+  int ObjFD = -1;
+  llvm::SmallString<128> ObjFile;
+  if (llvm::sys::fs::createTemporaryFile("kernel", "o", ObjFD, ObjFile))
+    return llvm::make_error<llvm::StringError>(
+        "Failed to create a temporary object file.",
+        llvm::inconvertibleErrorCode());
+  llvm::FileRemover ObjRemover(ObjFile);
+  {
+    llvm::raw_fd_ostream OS(ObjFD, /*shouldClose=*/true);
+    OS << llvm::StringRef(Object.data(), Object.size());
+  }
+
+  llvm::SmallString<128> HsacoFile;
+  if (llvm::sys::fs::createTemporaryFile("kernel", "hsaco", HsacoFile))
+    return llvm::make_error<llvm::StringError>(
+        "Failed to create a temporary code object file.",
+        llvm::inconvertibleErrorCode());
+  llvm::FileRemover HsacoRemover(HsacoFile);
+
+  llvm::StringRef Args[] = {"ld.lld", "-shared", "--no-undefined",
+                            ObjFile,  "-o",      HsacoFile};
+  if (llvm::sys::ExecuteAndWait(*LLDPath, Args) != 0)
+    return llvm::make_error<llvm::StringError>("ld.lld invocation failed.",
+                                               llvm::inconvertibleErrorCode());
+
+  auto HsacoBuf = llvm::MemoryBuffer::getFile(HsacoFile, /*IsText=*/false);
+  if (!HsacoBuf)
+    return llvm::make_error<llvm::StringError>(
+        "Failed to read the code object.", llvm::inconvertibleErrorCode());
+
+  llvm::StringRef Buffer = (*HsacoBuf)->getBuffer();
+  HSACOContent.assign(Buffer.begin(), Buffer.end());
+  return llvm::StringRef(HSACOContent.data(), HSACOContent.size());
+}
+
+llvm::Error IncrementalHIPDeviceParser::GenerateOffloadBundle() {
+  static constexpr unsigned CodeObjectAlign = 4096;
+
+  const PartialTranslationUnit &PTU = PTUs.back();
+
+  llvm::SmallString<128> HostFile;
+  if (llvm::sys::fs::createTemporaryFile("hip-host", "", HostFile))
+    return llvm::make_error<llvm::StringError>(
+        "Failed to create a temporary host bundle input.",
+        llvm::inconvertibleErrorCode());
+  llvm::FileRemover HostRemover(HostFile);
+
+  llvm::SmallString<128> DeviceFile;
+  int DeviceFD = -1;
+  if (llvm::sys::fs::createTemporaryFile("hip-device", "hsaco", DeviceFD,
+                                         DeviceFile))
+    return llvm::make_error<llvm::StringError>(
+        "Failed to create a temporary code object file.",
+        llvm::inconvertibleErrorCode());
+  llvm::FileRemover DeviceRemover(DeviceFile);
+  {
+    llvm::raw_fd_ostream OS(DeviceFD, /*shouldClose=*/true);
+    OS << llvm::StringRef(HSACOContent.data(), HSACOContent.size());
+  }
+
+  llvm::SmallString<128> BundleFile;
+  if (llvm::sys::fs::createTemporaryFile("hip-bundle", "hipfb", BundleFile))
+    return llvm::make_error<llvm::StringError>(
+        "Failed to create a temporary offload bundle file.",
+        llvm::inconvertibleErrorCode());
+  llvm::FileRemover BundleRemover(BundleFile);
+
+  // Triples use the normalized 4-field form ending in a dash; the device entry
+  // additionally appends the offload arch, e.g.
+  // "hip-amdgcn-amd-amdhsa--gfx90a".
+  std::string HostTriple = "host-" + llvm::sys::getProcessTriple() + "-";
+  std::string DeviceTriple =
+      "hip-" + PTU.TheModule->getTargetTriple().str() + "--" + TargetOpts.CPU;
+
+  OffloadBundlerConfig Config;
+  Config.FilesType = "o";
+  Config.BundleAlignment = CodeObjectAlign;
+  Config.HostInputIndex = 0;
+  Config.TargetNames = {HostTriple, DeviceTriple};
+  Config.InputFileNames = {std::string(HostFile), std::string(DeviceFile)};
+  Config.OutputFileNames = {std::string(BundleFile)};
+
+  if (llvm::Error Err = OffloadBundler(Config).BundleFiles())
+    return Err;
+
+  auto BundleBuf = llvm::MemoryBuffer::getFile(BundleFile, /*IsText=*/false);
+  if (!BundleBuf)
+    return llvm::make_error<llvm::StringError>(
+        "Failed to read the offload bundle.", llvm::inconvertibleErrorCode());
+
+  std::string BundleFileName = "/" + PTU.TheModule->getName().str() + ".hipfb";
+  VFS->addFile(BundleFileName, 0,
+               llvm::MemoryBuffer::getMemBufferCopy((*BundleBuf)->getBuffer()));
+
+  CodeGenOpts.OffloadBinaryToEmbedFile = std::move(BundleFileName);
+  return llvm::Error::success();
+}
+
+IncrementalHIPDeviceParser::~IncrementalHIPDeviceParser() {}
+
 IncrementalCUDADeviceParser::IncrementalCUDADeviceParser(
     CompilerInstance &DeviceInstance, CompilerInstance &HostInstance,
     IncrementalAction *DeviceAct,
@@ -45,18 +226,12 @@ IncrementalCUDADeviceParser::IncrementalCUDADeviceParser(
 
 llvm::Expected<llvm::StringRef> IncrementalCUDADeviceParser::GeneratePTX() {
   auto &PTU = PTUs.back();
-  std::string Error;
-
-  const llvm::Target *Target = llvm::TargetRegistry::lookupTarget(
-      PTU.TheModule->getTargetTriple(), Error);
-  if (!Target)
-    return llvm::make_error<llvm::StringError>(std::move(Error),
-                                               std::error_code());
-  llvm::TargetOptions TO = llvm::TargetOptions();
-  llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
-      PTU.TheModule->getTargetTriple(), TargetOpts.CPU, "", TO,
-      llvm::Reloc::Model::PIC_);
-  PTU.TheModule->setDataLayout(TargetMachine->createDataLayout());
+
+  llvm::Expected<llvm::TargetMachine *> TMOrErr =
+      getOrCreateTargetMachine(TM, *PTU.TheModule, TargetOpts.CPU);
+  if (!TMOrErr)
+    return TMOrErr.takeError();
+  llvm::TargetMachine *TargetMachine = *TMOrErr;
 
   PTXCode.clear();
   llvm::raw_svector_ostream dest(PTXCode);
@@ -69,9 +244,7 @@ llvm::Expected<llvm::StringRef> IncrementalCUDADeviceParser::GeneratePTX() {
         llvm::inconvertibleErrorCode());
   }
 
-  if (!PM.run(*PTU.TheModule))
-    return llvm::make_error<llvm::StringError>("Failed to emit PTX code.",
-                                               llvm::inconvertibleErrorCode());
+  PM.run(*PTU.TheModule);
 
   PTXCode += '\0';
   while (PTXCode.size() % 8)
diff --git a/clang/lib/Interpreter/DeviceOffload.h b/clang/lib/Interpreter/DeviceOffload.h
index a31bd5a0499b8..3e326e566a5bb 100644
--- a/clang/lib/Interpreter/DeviceOffload.h
+++ b/clang/lib/Interpreter/DeviceOffload.h
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements classes required for offloading to CUDA devices.
+// This file implements classes required for offloading to HIP and CUDA devices.
 //
 //===----------------------------------------------------------------------===//
 
@@ -14,9 +14,15 @@
 #define LLVM_CLANG_LIB_INTERPRETER_DEVICE_OFFLOAD_H
 
 #include "IncrementalParser.h"
-#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Error.h"
 #include "llvm/Support/VirtualFileSystem.h"
 
+#include <memory>
+
+namespace llvm {
+class TargetMachine;
+} // namespace llvm
+
 namespace clang {
 struct PartialTranslationUnit;
 class CompilerInstance;
@@ -24,6 +30,33 @@ class CodeGenOptions;
 class TargetOptions;
 class IncrementalAction;
 
+class IncrementalHIPDeviceParser : public IncrementalParser {
+
+public:
+  IncrementalHIPDeviceParser(
+      CompilerInstance &DeviceInstance, CompilerInstance &HostInstance,
+      IncrementalAction *DeviceAct,
+      llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> VFS,
+      llvm::Error &Err, std::list<PartialTranslationUnit> &PTUs);
+
+  llvm::Expected<TranslationUnitDecl *> Parse(llvm::StringRef Input) override;
+
+  llvm::Expected<llvm::StringRef> GenerateHSACO();
+
+  llvm::Error GenerateOffloadBundle();
+
+  ~IncrementalHIPDeviceParser();
+
+protected:
+  CompilerInstance &DeviceCI;
+  llvm::SmallVector<char, 1024> HSACOContent;
+  llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> VFS;
+  CodeGenOptions &CodeGenOpts; // Host opts, intentionally a reference.
+  const CodeGenOptions &DeviceCodeGenOpts;
+  const TargetOptions &TargetOpts;
+  std::unique_ptr<llvm::TargetMachine> TM;
+};
+
 class IncrementalCUDADeviceParser : public IncrementalParser {
 
 public:
@@ -48,6 +81,7 @@ class IncrementalCUDADeviceParser : public IncrementalParser {
   llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> VFS;
   CodeGenOptions &CodeGenOpts; // Intentionally a reference.
   const TargetOptions &TargetOpts;
+  std::unique_ptr<llvm::TargetMachine> TM;
 };
 
 } // namespace clang



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