[NewOffloadModel] Add additional options for clang-sycl-linker

clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp

@@ -160,6 +160,10 @@ static bool CanonicalPrefixes = true;
 
 using OffloadingImage = OffloadBinary::OffloadingImage;
 
+// TODO: Remove this once the linking and backend compilation have been fully
+// migrated to clang-sycl-linker.
+bool UseClangSYCLLinker = false;
+
 namespace llvm {
 // Provide DenseMapInfo so that OffloadKind can be used in a DenseMap.
 template <> struct DenseMapInfo<OffloadKind> {
@@ -1714,6 +1718,50 @@ Error extractBundledObjects(StringRef Filename, const ArgList &Args,
 } // namespace sycl
 
 namespace generic {
+// Forwards all required flags to the clang-sycl-linker via -Xlinker.
+static void appendClangSYCLLinkerArgs(const ArgList &Args,
+                                      SmallVectorImpl<StringRef> &CmdArgs,
+                                      const llvm::Triple &Triple,
+                                      StringRef Arch) {
+  auto XLinker = [&](const Twine &Arg) {
+    CmdArgs.append({"-Xlinker", Args.MakeArgString(Arg)});
+  };
+
+  XLinker("--triple=" + Triple.getTriple());
+  if (!Arch.empty())
+    XLinker("--arch=" + Arch);
+
+  static const OptSpecifier DirectOpts[] = {
+      OPT_save_temps,
+      OPT_dry_run,
+      OPT_print_wrapped_module,
+      OPT_sycl_thin_lto,
+      OPT_sycl_allow_device_image_dependencies,
+      OPT_sycl_remove_unused_external_funcs,
+      OPT_no_sycl_remove_unused_external_funcs,
+      OPT_sycl_device_code_split_esimd,
+      OPT_no_sycl_device_code_split_esimd,
+      OPT_sycl_add_default_spec_consts_image,
+      OPT_no_sycl_add_default_spec_consts_image,
+  };
+  for (OptSpecifier Opt : DirectOpts) {
+    if (Arg *A = Args.getLastArg(Opt)) {
+      XLinker("--" + A->getOption().getName().str());
+    }
+  }
+
+  static const OptSpecifier ValueOpts[] = {
+      OPT_sycl_dump_device_code_EQ,  OPT_llvm_spirv_options_EQ,
+      OPT_sycl_post_link_options_EQ, OPT_syclbin_EQ,
+      OPT_bitcode_library_EQ,
+  };
+  for (OptSpecifier Opt : ValueOpts) {
+    if (const opt::Arg *A = Args.getLastArg(Opt)) {
+      XLinker("--" + A->getOption().getName().str() + A->getValue());
+    }
+  }
+}
+
 Expected<StringRef> clang(ArrayRef<StringRef> InputFiles, const ArgList &Args,
                           bool IsSYCLKind = false) {
   llvm::TimeTraceScope TimeScope("Clang");
@@ -1752,6 +1800,17 @@ Expected<StringRef> clang(ArrayRef<StringRef> InputFiles, const ArgList &Args,
           (Triple.isNativeCPU() ? HostTriple : Triple).getTriple()),
   };
 
+  if (UseClangSYCLLinker) {
+    CmdArgs.push_back("-fsycl");
+    CmdArgs.push_back("--sycl-link");
+    appendClangSYCLLinkerArgs(Args, CmdArgs, Triple, Arch);
+    for (StringRef InputFile : InputFiles)
+      CmdArgs.append({"-Xlinker", Args.MakeArgString(InputFile)});
+    if (Error Err = executeCommands(*ClangPath, CmdArgs))
+      return std::move(Err);
+    return *TempFileOrErr;
+  }
+
   if (!Arch.empty())
     Triple.isAMDGPU() ? CmdArgs.push_back(Args.MakeArgString("-mcpu=" + Arch))
                       : CmdArgs.push_back(Args.MakeArgString("-march=" + Arch));

clang/tools/clang-sycl-linker/SYCLLinkOpts.td

@@ -54,3 +54,48 @@ def ocloc_options_EQ : Joined<["--", "-"], "ocloc-options=">,
 def opencl_aot_options_EQ : Joined<["--", "-"], "opencl-aot-options=">,
   Flags<[LinkerOnlyOption]>,
   HelpText<"Options passed to opencl-aot for Intel CPU AOT compilation">;
+
+def llvm_spirv_options_EQ : Joined<["--", "-"], "llvm-spirv-options=">,
+  Flags<[LinkerOnlyOption]>,
+  HelpText<"Options passed to llvm-spirv for LLVM IR to SPIR-V translation">;
+
+def sycl_post_link_options_EQ : Joined<["--", "-"], "sycl-post-link-options=">,
+  Flags<[LinkerOnlyOption]>,
+  HelpText<"Options passed to sycl-post-link tool">;
+
+// Options to specify additional bitcode libraries linked with -only-needed.
+def bitcode_library_EQ : Joined<["--"], "bitcode-library=">,
+  Flags<[LinkerOnlyOption]>, MetaVarName<"<kind>-<triple>-<arch>=<path>">,
+  HelpText<"Extra bitcode library to link">;
+
+def no_canonical_prefixes : Flag<["--"], "no-canonical-prefixes">,
+  Flags<[LinkerOnlyOption]>,
+  HelpText<"Do not resolve symbolic links, turn relative paths into absolute ones, or do anything else to identify the executable">;
+
+// Extra SYCL options to help generate sycl-post-link options that also depend
+// on the target triple.
+def sycl_remove_unused_external_funcs : Flag<["--", "-"], "sycl-remove-unused-external-funcs">,
+  Flags<[LinkerOnlyOption, HelpHidden]>;
+def no_sycl_remove_unused_external_funcs : Flag<["--", "-"], "no-sycl-remove-unused-external-funcs">,
+  Flags<[LinkerOnlyOption, HelpHidden]>;
+def sycl_device_code_split_esimd : Flag<["--", "-"], "sycl-device-code-split-esimd">,
+  Flags<[LinkerOnlyOption, HelpHidden]>;
+def no_sycl_device_code_split_esimd : Flag<["--", "-"], "no-sycl-device-code-split-esimd">,
+  Flags<[LinkerOnlyOption, HelpHidden]>;
+def sycl_add_default_spec_consts_image : Flag<["--", "-"], "sycl-add-default-spec-consts-image">,
+  Flags<[LinkerOnlyOption, HelpHidden]>;
+def no_sycl_add_default_spec_consts_image : Flag<["--", "-"], "no-sycl-add-default-spec-consts-image">,
+  Flags<[LinkerOnlyOption, HelpHidden]>;
+
+def sycl_thin_lto : Flag<["--", "-"], "sycl-thin-lto">,
+Flags<[LinkerOnlyOption]>,  HelpText<"Link SYCL device code using thinLTO">;
+
+// Options to enable/disable device dynamic linking.
+def sycl_allow_device_image_dependencies : Flag<["--", "-"], "sycl-allow-device-image-dependencies">,
+  Flags<[LinkerOnlyOption, HelpHidden]>,
+  HelpText<"Allow dependencies between device code images">;
+
+// Options to force the output to be of the SYCLBIN format.
+def syclbin_EQ : Joined<["--", "-"], "syclbin=">,
+  Flags<[LinkerOnlyOption]>,
+  HelpText<"Output in the SYCLBIN binary format in the state specified by <arg> (input, object or executable)">;