[HIP] search fatbin symbols for libs passed by -l

For -fgpu-rdc linking, clang needs to collect undefined fatbin
symbols and resolve them to the embedded fatbin.

This has been done for object files and archive files passed
as input files to clang.

However, the same action is not performed for archive files passed
through -l options, which causes missing fatbin symbols.

Author: yxsamliu

clang/lib/Driver/ToolChains/HIPUtility.cpp

@@ -52,13 +52,16 @@ static std::string normalizeForBundler(const llvm::Triple &T,
 // input object or archive files.
 class HIPUndefinedFatBinSymbols {
 public:
-  HIPUndefinedFatBinSymbols(const Compilation &C)
-      : C(C), DiagID(C.getDriver().getDiags().getCustomDiagID(
-                  DiagnosticsEngine::Error,
-                  "Error collecting HIP undefined fatbin symbols: %0")),
+  HIPUndefinedFatBinSymbols(const Compilation &C,
+                            const llvm::opt::ArgList &Args_)
+      : C(C), Args(Args_),
+        DiagID(C.getDriver().getDiags().getCustomDiagID(
+            DiagnosticsEngine::Error,
+            "Error collecting HIP undefined fatbin symbols: %0")),
         Quiet(C.getArgs().hasArg(options::OPT__HASH_HASH_HASH)),
         Verbose(C.getArgs().hasArg(options::OPT_v)) {
     populateSymbols();
+    processStaticLibraries();
     if (Verbose) {
       for (const auto &Name : FatBinSymbols)
         llvm::errs() << "Found undefined HIP fatbin symbol: " << Name << "\n";
@@ -76,8 +79,75 @@ class HIPUndefinedFatBinSymbols {
     return GPUBinHandleSymbols;
   }
 
+  // Collect symbols from static libraries specified by -l options.
+  void processStaticLibraries() {
+    llvm::SmallVector<llvm::StringRef, 16> LibNames;
+    llvm::SmallVector<llvm::StringRef, 16> LibPaths;
+    llvm::SmallVector<llvm::StringRef, 16> ExactLibNames;
+    llvm::Triple Triple(C.getDriver().getTargetTriple());
+    bool IsMSVC = Triple.isWindowsMSVCEnvironment();
+    llvm::StringRef Ext = IsMSVC ? ".lib" : ".a";
+
+    for (const auto *Arg : Args.filtered(options::OPT_l)) {
+      llvm::StringRef Value = Arg->getValue();
+      if (Value.starts_with(":"))
+        ExactLibNames.push_back(Value.drop_front());
+      else
+        LibNames.push_back(Value);
+    }
+    for (const auto *Arg : Args.filtered(options::OPT_L)) {
+      auto Path = Arg->getValue();
+      LibPaths.push_back(Path);
+      if (Verbose)
+        llvm::errs() << "HIP fatbin symbol search uses library path:  " << Path
+                     << "\n";
+    }
+
+    auto ProcessLib = [&](llvm::StringRef LibName, bool IsExact) {
+      llvm::SmallString<256> FullLibName;
+      if (IsExact)
+        FullLibName = LibName;
+      else {
+        if (IsMSVC)
+          (llvm::Twine(LibName) + Ext).toVector(FullLibName);
+        else
+          (llvm::Twine("lib") + LibName + Ext).toVector(FullLibName);
+      }
+
+      bool Found = false;
+      for (const auto &Path : LibPaths) {
+        llvm::SmallString<256> FullPath = Path;
+        llvm::sys::path::append(FullPath, FullLibName);
+
+        if (llvm::sys::fs::exists(FullPath)) {
+          if (Verbose)
+            llvm::errs() << "HIP fatbin symbol search found library: "
+                         << FullPath << "\n";
+          auto BufferOrErr = llvm::MemoryBuffer::getFile(FullPath);
+          if (!BufferOrErr) {
+            errorHandler(llvm::errorCodeToError(BufferOrErr.getError()));
+            continue;
+          }
+          processInput(BufferOrErr.get()->getMemBufferRef());
+          Found = true;
+          break;
+        }
+      }
+      if (!Found && Verbose)
+        llvm::errs() << "HIP fatbin symbol search could not find library: "
+                     << FullLibName << "\n";
+    };
+
+    for (const auto &LibName : ExactLibNames)
+      ProcessLib(LibName, true);
+
+    for (const auto &LibName : LibNames)
+      ProcessLib(LibName, false);
+  }
+
 private:
   const Compilation &C;
+  const llvm::opt::ArgList &Args;
   unsigned DiagID;
   bool Quiet;
   bool Verbose;
@@ -301,7 +371,7 @@ void HIP::constructGenerateObjFileFromHIPFatBinary(
   auto HostTriple =
       C.getSingleOffloadToolChain<Action::OFK_Host>()->getTriple();
 
-  HIPUndefinedFatBinSymbols Symbols(C);
+  HIPUndefinedFatBinSymbols Symbols(C, Args);
 
   std::string PrimaryHipFatbinSymbol;
   std::string PrimaryGpuBinHandleSymbol;

clang/test/Driver/hip-toolchain-rdc.hip

@@ -20,6 +20,29 @@
 // RUN:   %S/Inputs/hip_multiple_inputs/b.hip \
 // RUN: 2>&1 | FileCheck -check-prefixes=CHECK,MSVC %s
 
+// Test fatbin symbol search for -l libraries.
+
+// RUN: touch librdctest.a rdctest2.bin
+// RUN: %clang -### --target=x86_64-linux-gnu -v \
+// RUN:   -fgpu-rdc -nogpuinc -nogpulib \
+// RUN:   --no-offload-new-driver -L. -lrdctest -l:rdctest2.bin \
+// RUN:   %s \
+// RUN: 2>&1 | FileCheck -check-prefixes=LIB,LNX-LIB %s
+// RUN: rm librdctest.a rdctest2.bin
+
+// RUN: touch rdctest.lib rdctest2.bin
+// RUN: %clang -### --target=x86_64-pc-windows-msvc -v \
+// RUN:   -fgpu-rdc -nogpuinc -nogpulib \
+// RUN:   --no-offload-new-driver -L. -lrdctest -l:rdctest2.bin \
+// RUN:   %s \
+// RUN: 2>&1 | FileCheck -check-prefixes=LIB,MSVC-LIB %s
+// RUN: rm rdctest.lib rdctest2.bin
+
+// LIB: HIP fatbin symbol search uses library path: .
+// LIB: HIP fatbin symbol search found library: ./rdctest2.bin
+// LNX-LIB: HIP fatbin symbol search found library: ./librdctest.a
+// MSVC-LIB: HIP fatbin symbol search found library: ./rdctest.lib
+
 // check HIP fatbin and gpubin handle symbols and code object alignment in dumped llvm-mc input
 // CHECK: Found undefined HIP fatbin symbol: __hip_fatbin_[[ID1:[0-9a-f]+]]
 // CHECK: Found undefined HIP fatbin symbol: __hip_fatbin_[[ID2:[0-9a-f]+]]