[Clang] Append target search paths for direct offloading compilation

[jhuber6]

Summary:
Recent changes to the libc project caused the headers to be installed
to include/<triple> for the GPU and the libraries to be in
lib/<triple>. This means we should automatically append these search
paths so they can be found by default. This allows the following to work
targeting AMDGPU.

$ clang foo.c -flto -mcpu=native --target=amdgcn-amd-amdhsa -lc <install>/lib/amdgcn-amd-amdhsa/crt1.o
$ amdhsa-loader a.out

[llvmbot]

@llvm/pr-subscribers-clang-driver
@llvm/pr-subscribers-backend-amdgpu

@llvm/pr-subscribers-clang

Author: Joseph Huber (jhuber6)

Changes

Summary:
Recent changes to the libc project caused the headers to be installed
to include/<triple> for the GPU and the libraries to be in
lib/<triple>. This means we should automatically append these search
paths so they can be found by default. This allows the following to work
targeting AMDGPU.

$ clang foo.c -flto -mcpu=native --target=amdgcn-amd-amdhsa -lc <install>/lib/amdgcn-amd-amdhsa/crt1.o
$ amdhsa-loader a.out

---

Full diff: https://github.com/llvm/llvm-project/pull/82699.diff

4 Files Affected:

• (modified) clang/lib/Driver/ToolChains/AMDGPU.cpp (+1)
• (modified) clang/lib/Driver/ToolChains/Clang.cpp (+2-2)
• (modified) clang/lib/Driver/ToolChains/Cuda.cpp (+4)
• (modified) clang/test/Driver/gpu-libc-headers.c (+8-1)

diff --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp
index 60e8c123c591d2..6fcbcffd6f0d67 100644
--- a/clang/lib/Driver/ToolChains/AMDGPU.cpp
+++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp
@@ -625,6 +625,7 @@ void amdgpu::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   addLinkerCompressDebugSectionsOption(getToolChain(), Args, CmdArgs);
   Args.AddAllArgs(CmdArgs, options::OPT_L);
+  getToolChain().AddFilePathLibArgs(Args, CmdArgs);
   AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs, JA);
   if (C.getDriver().isUsingLTO())
     addLTOOptions(getToolChain(), Args, CmdArgs, Output, Inputs[0],
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 7c0409f0c3097a..6e1b7e8657d0dc 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -1111,8 +1111,8 @@ void Clang::AddPreprocessingOptions(Compilation &C, const JobAction &JA,
         C.getActiveOffloadKinds() == Action::OFK_None) {
       SmallString<128> P(llvm::sys::path::parent_path(D.InstalledDir));
       llvm::sys::path::append(P, "include");
-      llvm::sys::path::append(P, "gpu-none-llvm");
-      CmdArgs.push_back("-c-isystem");
+      llvm::sys::path::append(P, getToolChain().getTripleString());
+      CmdArgs.push_back("-internal-isystem");
       CmdArgs.push_back(Args.MakeArgString(P));
     } else if (C.getActiveOffloadKinds() == Action::OFK_OpenMP) {
       // TODO: CUDA / HIP include their own headers for some common functions
diff --git a/clang/lib/Driver/ToolChains/Cuda.cpp b/clang/lib/Driver/ToolChains/Cuda.cpp
index ed5924c3b73b55..8c7a96289559c1 100644
--- a/clang/lib/Driver/ToolChains/Cuda.cpp
+++ b/clang/lib/Driver/ToolChains/Cuda.cpp
@@ -609,6 +609,10 @@ void NVPTX::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   // Add paths specified in LIBRARY_PATH environment variable as -L options.
   addDirectoryList(Args, CmdArgs, "-L", "LIBRARY_PATH");
 
+  // Add standard library search paths passed on the command line.
+  Args.AddAllArgs(CmdArgs, options::OPT_L);
+  getToolChain().AddFilePathLibArgs(Args, CmdArgs);
+
   // Add paths for the default clang library path.
   SmallString<256> DefaultLibPath =
       llvm::sys::path::parent_path(TC.getDriver().Dir);
diff --git a/clang/test/Driver/gpu-libc-headers.c b/clang/test/Driver/gpu-libc-headers.c
index 74e9a764dfcb35..356a401550399d 100644
--- a/clang/test/Driver/gpu-libc-headers.c
+++ b/clang/test/Driver/gpu-libc-headers.c
@@ -10,10 +10,17 @@
 // CHECK-HEADERS: "-cc1"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}llvm_libc_wrappers"{{.*}}"-isysroot" "./"
 // CHECK-HEADERS: "-cc1"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}llvm_libc_wrappers"{{.*}}"-isysroot" "./"
 
+// RUN:   %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx90a --sysroot=./ \
+// RUN:     -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-AMDGPU
+// RUN:   %clang -### --target=nvptx64-nvidia-cuda -march=sm_89 --sysroot=./ \
+// RUN:     -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-NVPTX
+// CHECK-HEADERS-AMDGPU: "-cc1"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}amdgcn-amd-amdhsa"{{.*}}"-isysroot" "./"
+// CHECK-HEADERS-NVPTX: "-cc1"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}nvptx64-nvidia-cuda"{{.*}}"-isysroot" "./"
+
 // RUN:   %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
 // RUN:     -nogpuinc %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-DISABLED
 // RUN:   %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
 // RUN:     -nostdinc %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-DISABLED
 // RUN:   %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
 // RUN:     -nobuiltininc %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-DISABLED
-// CHECK-HEADERS-DISABLED-NOT: "-cc1"{{.*}}"-c-isystem" "{{.*}}include{{.*}}gpu-none-llvm"
+// CHECK-HEADERS-DISABLED-NOT: "-cc1"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}gpu-none-llvm"

[jplehr]

LG