[clang] Fix amdgpu-arch for dll name on Windows (PR #101350)

[Yaxun Liu via cfe-commits]

https://github.com/yxsamliu updated https://github.com/llvm/llvm-project/pull/101350

>From e7c39dbcb05d8fa9232a68c90b0ec4fc4d2a126b Mon Sep 17 00:00:00 2001
From: "Yaxun (Sam) Liu" <yaxun.liu at amd.com>
Date: Wed, 31 Jul 2024 09:23:05 -0400
Subject: [PATCH] Fix amdgpu-arch for dll name on Windows

Recently HIP runtime changed dll name to amdhip64_n.dll on Windows, where
n is ROCm major version number.

Fix amdgpu-arch to search for amdhip64_n.dll on Windows.
---
 clang/tools/amdgpu-arch/AMDGPUArch.cpp      |   3 +
 clang/tools/amdgpu-arch/AMDGPUArchByHIP.cpp | 123 +++++++++++++++++++-
 2 files changed, 122 insertions(+), 4 deletions(-)

diff --git a/clang/tools/amdgpu-arch/AMDGPUArch.cpp b/clang/tools/amdgpu-arch/AMDGPUArch.cpp
index 7ae57b7877e1f..fefd4f08d5ed2 100644
--- a/clang/tools/amdgpu-arch/AMDGPUArch.cpp
+++ b/clang/tools/amdgpu-arch/AMDGPUArch.cpp
@@ -21,6 +21,9 @@ static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
 // Mark all our options with this category.
 static cl::OptionCategory AMDGPUArchCategory("amdgpu-arch options");
 
+cl::opt<bool> Verbose("verbose", cl::desc("Enable verbose output"),
+                      cl::init(false), cl::cat(AMDGPUArchCategory));
+
 static void PrintVersion(raw_ostream &OS) {
   OS << clang::getClangToolFullVersion("amdgpu-arch") << '\n';
 }
diff --git a/clang/tools/amdgpu-arch/AMDGPUArchByHIP.cpp b/clang/tools/amdgpu-arch/AMDGPUArchByHIP.cpp
index 7338872dbf32f..0ae4cbe34e934 100644
--- a/clang/tools/amdgpu-arch/AMDGPUArchByHIP.cpp
+++ b/clang/tools/amdgpu-arch/AMDGPUArchByHIP.cpp
@@ -11,9 +11,22 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/DynamicLibrary.h"
 #include "llvm/Support/Error.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
+#include "llvm/Support/Program.h"
 #include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
 
 using namespace llvm;
 
@@ -31,16 +44,118 @@ typedef hipError_t (*hipGetDeviceCount_t)(int *);
 typedef hipError_t (*hipDeviceGet_t)(int *, int);
 typedef hipError_t (*hipGetDeviceProperties_t)(hipDeviceProp_t *, int);
 
-int printGPUsByHIP() {
+extern cl::opt<bool> Verbose;
+
 #ifdef _WIN32
-  constexpr const char *DynamicHIPPath = "amdhip64.dll";
+static std::vector<std::string> getSearchPaths() {
+  std::vector<std::string> Paths;
+
+  // Get the directory of the current executable
+  if (auto MainExe = sys::fs::getMainExecutable(nullptr, nullptr);
+      !MainExe.empty())
+    Paths.push_back(sys::path::parent_path(MainExe).str());
+
+  // Get the system directory
+  wchar_t SystemDirectory[MAX_PATH];
+  if (GetSystemDirectoryW(SystemDirectory, MAX_PATH) > 0) {
+    std::string Utf8SystemDir;
+    if (convertUTF16ToUTF8String(
+            ArrayRef<UTF16>(reinterpret_cast<const UTF16 *>(SystemDirectory),
+                            wcslen(SystemDirectory)),
+            Utf8SystemDir))
+      Paths.push_back(Utf8SystemDir);
+  }
+
+  // Get the Windows directory
+  wchar_t WindowsDirectory[MAX_PATH];
+  if (GetWindowsDirectoryW(WindowsDirectory, MAX_PATH) > 0) {
+    std::string Utf8WindowsDir;
+    if (convertUTF16ToUTF8String(
+            ArrayRef<UTF16>(reinterpret_cast<const UTF16 *>(WindowsDirectory),
+                            wcslen(WindowsDirectory)),
+            Utf8WindowsDir))
+      Paths.push_back(Utf8WindowsDir);
+  }
+
+  // Get the current working directory
+  SmallVector<char, 256> CWD;
+  if (sys::fs::current_path(CWD))
+    Paths.push_back(std::string(CWD.begin(), CWD.end()));
+
+  // Get the PATH environment variable
+  if (auto PathEnv = sys::Process::GetEnv("PATH")) {
+    SmallVector<StringRef, 16> PathList;
+    StringRef(*PathEnv).split(PathList, sys::EnvPathSeparator);
+    for (auto &Path : PathList)
+      Paths.push_back(Path.str());
+  }
+
+  return Paths;
+}
+
+// Custom comparison function for dll name
+static bool compareVersions(const std::string &a, const std::string &b) {
+  // Extract version numbers
+  int versionA = std::stoi(a.substr(a.find_last_of('_') + 1));
+  int versionB = std::stoi(b.substr(b.find_last_of('_') + 1));
+  return versionA > versionB;
+}
+
+#endif
+
+// On Windows, prefer amdhip64_n.dll where n is ROCm major version and greater
+// value of n takes precedence. If amdhip64_n.dll is not found, fall back to
+// amdhip64.dll. The reason is that a normal driver installation only has
+// amdhip64_n.dll but we do not know what n is since this progrm may be used
+// with a future version of HIP runtime.
+//
+// On Linux, always use default libamdhip64.so.
+static std::pair<std::string, bool> findNewestHIPDLL() {
+#ifdef _WIN32
+  StringRef HipDLLPrefix = "amdhip64_";
+  StringRef HipDLLSuffix = ".dll";
+
+  std::vector<std::string> SearchPaths = getSearchPaths();
+  std::vector<std::string> DLLNames;
+
+  for (const auto &Dir : SearchPaths) {
+    std::error_code EC;
+    for (sys::fs::directory_iterator DirIt(Dir, EC), DirEnd;
+         DirIt != DirEnd && !EC; DirIt.increment(EC)) {
+      StringRef Filename = sys::path::filename(DirIt->path());
+      if (Filename.starts_with(HipDLLPrefix) &&
+          Filename.ends_with(HipDLLSuffix))
+        DLLNames.push_back(sys::path::convert_to_slash(DirIt->path()));
+    }
+    if (!DLLNames.empty())
+      break;
+  }
+
+  if (DLLNames.empty())
+    return {"amdhip64.dll", true};
+
+  std::sort(DLLNames.begin(), DLLNames.end(), compareVersions);
+  return {DLLNames[0], false};
 #else
-  constexpr const char *DynamicHIPPath = "libamdhip64.so";
+  // On Linux, fallback to default shared object
+  return {"libamdhip64.so", true};
 #endif
+}
+
+int printGPUsByHIP() {
+  auto [DynamicHIPPath, IsFallback] = findNewestHIPDLL();
+
+  if (Verbose) {
+    if (IsFallback)
+      outs() << "Using default HIP runtime: " << DynamicHIPPath << "\n";
+    else
+      outs() << "Found HIP runtime: " << DynamicHIPPath << "\n";
+  }
 
   std::string ErrMsg;
   auto DynlibHandle = std::make_unique<llvm::sys::DynamicLibrary>(
-      llvm::sys::DynamicLibrary::getPermanentLibrary(DynamicHIPPath, &ErrMsg));
+      llvm::sys::DynamicLibrary::getPermanentLibrary(DynamicHIPPath.c_str(),
+                                                     &ErrMsg));
   if (!DynlibHandle->isValid()) {
     llvm::errs() << "Failed to load " << DynamicHIPPath << ": " << ErrMsg
                  << '\n';