[Clang] Forward arguments to the device compiler better

jhuber6 · jhuber6 · commit 8d2525023e0f · 2025-02-05T17:46:34.000-06:00
Summary:
Currently we have a subset of arguments that are handled specially to
keep them consistent between host and device compiles, however, this is
extremely hacky as it only works on a few predetermined options. This is
a holdover from the days before the linker wrapper shuttled all of its
arguments through `clang`. Now that we just use clang, all we need to do
is just use the `--device-compiler=` option to forward it there and let
the normal toolchain handle it.

For example,
```console
clang -fopenmp --offload-arch=gfx1030,sm_89 -Xarch_nvptx64 -O3 -foffload-lto
```
will forward the `-O3` to the LTO compilation only for the NVPTX
compilation.
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -9138,81 +9138,64 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
                                  const InputInfoList &Inputs,
                                  const ArgList &Args,
                                  const char *LinkingOutput) const {
-  const Driver &D = getToolChain().getDriver();
-  const llvm::Triple TheTriple = getToolChain().getTriple();
-  ArgStringList CmdArgs;
+  using namespace options;
+
+  // A list of permitted options that will be forwarded to the embedded device
+  // compilation job.
+  const llvm::DenseSet<unsigned> CompilerOptions{OPT_v,
+                                                 OPT_cuda_path_EQ,
+                                                 OPT_rocm_path_EQ,
+                                                 OPT_O_Group,
+                                                 OPT_g_Group,
+                                                 OPT_g_flags_Group,
+                                                 OPT_R_value_Group,
+                                                 OPT_R_Group,
+                                                 OPT_Xcuda_ptxas,
+                                                 OPT_ftime_report,
+                                                 OPT_save_temps,
+                                                 OPT_mcode_object_version_EQ,
+                                                 OPT_fno_lto,
+                                                 OPT_flto,
+                                                 OPT_flto_EQ};
+  const llvm::DenseSet<unsigned> LinkerOptions{OPT_mllvm};
+  auto ShouldForward = [&](const llvm::DenseSet<unsigned> &Set, Arg *A) {
+    return Set.contains(A->getOption().getID()) ||
+           (A->getOption().getGroup().isValid() &&
+            Set.contains(A->getOption().getGroup().getID()));
+  };
 
-  // Pass the CUDA path to the linker wrapper tool.
+  ArgStringList CmdArgs;
   for (Action::OffloadKind Kind : {Action::OFK_Cuda, Action::OFK_OpenMP}) {
     auto TCRange = C.getOffloadToolChains(Kind);
     for (auto &I : llvm::make_range(TCRange)) {
       const ToolChain *TC = I.second;
-      if (TC->getTriple().isNVPTX()) {
-        CudaInstallationDetector CudaInstallation(D, TheTriple, Args);
-        if (CudaInstallation.isValid())
-          CmdArgs.push_back(Args.MakeArgString(
-              "--cuda-path=" + CudaInstallation.getInstallPath()));
-        break;
+
+      // We do not use a bound architecture here so options passed only to a
+      // specific architecture via -Xarch_<cpu> will not be forwarded.
+      ArgStringList CompilerArgs;
+      ArgStringList LinkerArgs;
+      for (Arg *A : C.getArgsForToolChain(TC, /*BoundArch=*/"", Kind)) {
+        if (ShouldForward(CompilerOptions, A))
+          A->render(Args, CompilerArgs);
+        else if (ShouldForward(LinkerOptions, A))
+          A->render(Args, LinkerArgs);
       }
-    }
-  }
 
-  // Pass in the optimization level to use for LTO.
-  if (const Arg *A = Args.getLastArg(options::OPT_O_Group)) {
-    StringRef OOpt;
-    if (A->getOption().matches(options::OPT_O4) ||
-        A->getOption().matches(options::OPT_Ofast))
-      OOpt = "3";
-    else if (A->getOption().matches(options::OPT_O)) {
-      OOpt = A->getValue();
-      if (OOpt == "g")
-        OOpt = "1";
-      else if (OOpt == "s" || OOpt == "z")
-        OOpt = "2";
-    } else if (A->getOption().matches(options::OPT_O0))
-      OOpt = "0";
-    if (!OOpt.empty())
-      CmdArgs.push_back(Args.MakeArgString(Twine("--opt-level=O") + OOpt));
+      // Forward all of these to the appropriate toolchain.
+      for (StringRef Arg : CompilerArgs)
+        CmdArgs.push_back(Args.MakeArgString(
+            "--device-compiler=" + TC->getTripleString() + "=" + Arg));
+      for (StringRef Arg : LinkerArgs)
+        CmdArgs.push_back(Args.MakeArgString(
+            "--device-linker=" + TC->getTripleString() + "=" + Arg));
+    }
   }
 
   CmdArgs.push_back(
-      Args.MakeArgString("--host-triple=" + TheTriple.getTriple()));
+      Args.MakeArgString("--host-triple=" + getToolChain().getTripleString()));
   if (Args.hasArg(options::OPT_v))
     CmdArgs.push_back("--wrapper-verbose");
 
-  if (const Arg *A = Args.getLastArg(options::OPT_g_Group)) {
-    if (!A->getOption().matches(options::OPT_g0))
-      CmdArgs.push_back("--device-debug");
-  }
-
-  // code-object-version=X needs to be passed to clang-linker-wrapper to ensure
-  // that it is used by lld.
-  if (const Arg *A = Args.getLastArg(options::OPT_mcode_object_version_EQ)) {
-    CmdArgs.push_back(Args.MakeArgString("-mllvm"));
-    CmdArgs.push_back(Args.MakeArgString(
-        Twine("--amdhsa-code-object-version=") + A->getValue()));
-  }
-
-  for (const auto &A : Args.getAllArgValues(options::OPT_Xcuda_ptxas))
-    CmdArgs.push_back(Args.MakeArgString("--ptxas-arg=" + A));
-
-  // Forward remarks passes to the LLVM backend in the wrapper.
-  if (const Arg *A = Args.getLastArg(options::OPT_Rpass_EQ))
-    CmdArgs.push_back(Args.MakeArgString(Twine("--offload-opt=-pass-remarks=") +
-                                         A->getValue()));
-  if (const Arg *A = Args.getLastArg(options::OPT_Rpass_missed_EQ))
-    CmdArgs.push_back(Args.MakeArgString(
-        Twine("--offload-opt=-pass-remarks-missed=") + A->getValue()));
-  if (const Arg *A = Args.getLastArg(options::OPT_Rpass_analysis_EQ))
-    CmdArgs.push_back(Args.MakeArgString(
-        Twine("--offload-opt=-pass-remarks-analysis=") + A->getValue()));
-
-  if (Args.getLastArg(options::OPT_ftime_report))
-    CmdArgs.push_back("--device-compiler=-ftime-report");
-
-  if (Args.getLastArg(options::OPT_save_temps_EQ))
-    CmdArgs.push_back("--save-temps");
-
   // Construct the link job so we can wrap around it.
   Linker->ConstructJob(C, JA, Output, Inputs, Args, LinkingOutput);
   const auto &LinkCommand = C.getJobs().getJobs().back();
@@ -9236,13 +9219,6 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
                    options::OPT_fno_openmp_target_jit, false))
     CmdArgs.push_back("--embed-bitcode");
 
-  // Forward `-mllvm` arguments to the LLVM invocations if present.
-  for (Arg *A : Args.filtered(options::OPT_mllvm)) {
-    CmdArgs.push_back("-mllvm");
-    CmdArgs.push_back(A->getValue());
-    A->claim();
-  }
-
   // Pass in the C library for GPUs if present and not disabled.
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_r, options::OPT_nogpulib,
                    options::OPT_nodefaultlibs, options::OPT_nolibc,
@@ -9268,11 +9244,6 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
     });
   }
 
-  // If we disable the GPU C library support it needs to be forwarded to the
-  // link job.
-  if (!Args.hasFlag(options::OPT_gpulibc, options::OPT_nogpulibc, true))
-    CmdArgs.push_back("--device-compiler=-nolibc");
-
   // Add the linker arguments to be forwarded by the wrapper.
   CmdArgs.push_back(Args.MakeArgString(Twine("--linker-path=") +
                                        LinkCommand->getExecutable()));
diff --git a/clang/test/Driver/amdgpu-openmp-sanitize-options.c b/clang/test/Driver/amdgpu-openmp-sanitize-options.c
@@ -56,10 +56,10 @@
 // GPUSAN: {{"[^"]*clang[^"]*" "-cc1" "-triple" "amdgcn-amd-amdhsa" "-aux-triple" "x86_64-unknown-linux-gnu".* "-emit-llvm-bc".* "-target-cpu" "(gfx908|gfx900)".* "-fopenmp".* "-fsanitize=address".* "-x" "c".*}}
 // GPUSAN: {{"[^"]*clang-offload-packager[^"]*" "-o".* "--image=file=.*.bc,triple=amdgcn-amd-amdhsa,arch=gfx908(:xnack\-|:xnack\+)?,kind=openmp(,feature=(\-xnack|\+xnack))?"}}
 // GPUSAN: {{"[^"]*clang[^"]*" "-cc1" "-triple" "x86_64-unknown-linux-gnu".* "-fopenmp".* "-fsanitize=address".* "-fopenmp-targets=amdgcn-amd-amdhsa".* "-x" "ir".*}}
-// GPUSAN: {{"[^"]*clang-linker-wrapper[^"]*" "--host-triple=x86_64-unknown-linux-gnu" "--linker-path=[^"]*".* "--whole-archive" "[^"]*(libclang_rt.asan_static.a|libclang_rt.asan_static-x86_64.a)".* "--whole-archive" "[^"]*(libclang_rt.asan.a|libclang_rt.asan-x86_64.a)".*}}
+// GPUSAN: {{"[^"]*clang-linker-wrapper[^"]*".* "--host-triple=x86_64-unknown-linux-gnu".* "--linker-path=[^"]*".* "--whole-archive" "[^"]*(libclang_rt.asan_static.a|libclang_rt.asan_static-x86_64.a)".* "--whole-archive" "[^"]*(libclang_rt.asan.a|libclang_rt.asan-x86_64.a)".*}}
 
 // NOGPUSAN: {{"[^"]*clang[^"]*" "-cc1" "-triple" "x86_64-unknown-linux-gnu".* "-fopenmp".* "-fsanitize=address".* "-fopenmp-targets=amdgcn-amd-amdhsa".* "-x" "c".*}}
 // NOGPUSAN: {{"[^"]*clang[^"]*" "-cc1" "-triple" "amdgcn-amd-amdhsa" "-aux-triple" "x86_64-unknown-linux-gnu".* "-emit-llvm-bc".* "-target-cpu" "(gfx908|gfx900)".* "-fopenmp".* "-x" "c".*}}
 // NOGPUSAN: {{"[^"]*clang-offload-packager[^"]*" "-o".* "--image=file=.*.bc,triple=amdgcn-amd-amdhsa,arch=gfx908(:xnack\-|:xnack\+)?,kind=openmp(,feature=(\-xnack|\+xnack))?"}}
 // NOGPUSAN: {{"[^"]*clang[^"]*" "-cc1" "-triple" "x86_64-unknown-linux-gnu".* "-fopenmp".* "-fsanitize=address".* "-fopenmp-targets=amdgcn-amd-amdhsa".* "-x" "ir".*}}
-// NOGPUSAN: {{"[^"]*clang-linker-wrapper[^"]*" "--host-triple=x86_64-unknown-linux-gnu" "--linker-path=[^"]*".* "--whole-archive" "[^"]*(libclang_rt.asan_static.a|libclang_rt.asan_static-x86_64.a)".* "--whole-archive" "[^"]*(libclang_rt.asan.a|libclang_rt.asan-x86_64.a)".*}}
+// NOGPUSAN: {{"[^"]*clang-linker-wrapper[^"]*".* "--host-triple=x86_64-unknown-linux-gnu".* "--linker-path=[^"]*".* "--whole-archive" "[^"]*(libclang_rt.asan_static.a|libclang_rt.asan_static-x86_64.a)".* "--whole-archive" "[^"]*(libclang_rt.asan.a|libclang_rt.asan-x86_64.a)".*}}
diff --git a/clang/test/Driver/amdgpu-openmp-toolchain.c b/clang/test/Driver/amdgpu-openmp-toolchain.c
@@ -72,7 +72,7 @@
 
 // RUN: %clang -### -target x86_64-pc-linux-gnu -fopenmp --offload-arch=gfx90a \
 // RUN:   -O3 -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-OPT
-// CHECK-OPT: clang-linker-wrapper{{.*}}"--opt-level=O3"
+// CHECK-OPT: clang-linker-wrapper{{.*}}"--device-compiler=amdgcn-amd-amdhsa=-O3"
 
 // RUN:   %clang -### --target=x86_64-unknown-linux-gnu -emit-llvm -S -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx803 -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-WARN-ATOMIC
 // CHECK-WARN-ATOMIC-NOT: "-cc1" "-triple" "x86_64-unknown-linux-gnu"{{.*}}"-Werror=atomic-alignment"
@@ -84,4 +84,4 @@
 
 // RUN: %clang -### -target x86_64-pc-linux-gnu -nogpulib  -fopenmp --offload-arch=gfx90a \
 // RUN:   -ftime-report %s 2>&1 | FileCheck %s --check-prefix=CHECK-TIME-REPORT
-// CHECK-TIME-REPORT: clang-linker-wrapper{{.*}}"--device-compiler=-ftime-report"
+// CHECK-TIME-REPORT: clang-linker-wrapper{{.*}}"--device-compiler=amdgcn-amd-amdhsa=-ftime-report"
diff --git a/clang/test/Driver/openmp-offload.c b/clang/test/Driver/openmp-offload.c
@@ -184,13 +184,13 @@
 // RUN:   %clang -### --target=powerpc64le-linux -fopenmp=libomp -fopenmp-targets=powerpc64le-ibm-linux-gnu -g %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHK-NEW-DRIVER-DEBUG %s
 
-// CHK-NEW-DRIVER-DEBUG: clang-linker-wrapper{{.*}} "--device-debug"
+// CHK-NEW-DRIVER-DEBUG: clang-linker-wrapper{{.*}} "--device-compiler=powerpc64le-ibm-linux-gnu=-g"
 
 /// Check arguments to the linker wrapper
 // RUN:   %clang -### --target=powerpc64le-linux -fopenmp=libomp -fopenmp-targets=powerpc64le-ibm-linux-gnu \
 // RUN:     -mllvm -abc %s 2>&1 | FileCheck -check-prefix=CHK-NEW-DRIVER-MLLVM %s
 
-// CHK-NEW-DRIVER-MLLVM: clang-linker-wrapper{{.*}} "-abc"
+// CHK-NEW-DRIVER-MLLVM: clang-linker-wrapper{{.*}} "--device-linker=powerpc64le-ibm-linux-gnu=-mllvm" "--device-linker=powerpc64le-ibm-linux-gnu=-abc"
 
 //
 // Ensure that we generate the correct bindings for '-fsyntax-only' for OpenMP.
