[HIP] link HIP runtime library without --hip-link

[yaxunl]

Summary

When doing combined compilation/link for HIP source files, clang should link the HIP runtime library automatically without --hip-link.

[jhuber6]

So this is equivalent to nvcc implicitly calling -lcudart? I've had thoughts about the clang-linker-wrapper adding known runtime flags to the link job if it's not found. E.g. if we find a CUDA image we pass -lcudart.

[yaxunl]

In D156426#4538646, @jhuber6 wrote:

So this is equivalent to nvcc implicitly calling -lcudart? I've had thoughts about the clang-linker-wrapper adding known runtime flags to the link job if it's not found. E.g. if we find a CUDA image we pass -lcudart.

yes

[jhuber6]

clang/include/clang/Driver/Driver.h

712 ↗

(On Diff #544736)

Shouldn't we have access to the compilation? I figured we could check C.getActiveOffloadKinds() or w/e it's called.

[yaxunl]

clang/include/clang/Driver/Driver.h

712 ↗

(On Diff #544736)

yes that is a better solution. will do

[yaxunl]

revised by comments

[jhuber6]

LG, thanks.

[scchan]

clang/docs/HIPSupport.rst

71

clang++ -xhip --offload-arch=gfx906 sample.o -o sample
would also work?

[yaxunl]

clang/docs/HIPSupport.rst

71

yes. since it will create a HIP toolchain

[scchan]

LGTM thanks

clang/docs/HIPSupport.rst

.. code-block:: shell
    clang++ -c --offload-arch=gfx906 sample.hip -o sample.o
 
 To link a HIP program, use this command:
 
 .. code-block:: shell
 
    clang++ --hip-link --offload-arch=gfx906 sample.o -o sample
 
+In the above command, the ``--hip-link`` flag instructs Clang to link the HIP runtime library. However,
+the use of this flag is unnecessary if a HIP input file is already present in your program.
+
 For convenience, Clang also supports compiling and linking in a single step:
 
 .. code-block:: shell
 
-   clang++ --hip-link --offload-arch=gfx906 -xhip sample.cpp -o sample
+   clang++ --offload-arch=gfx906 -xhip sample.cpp -o sample
 
 In the above commands, ``gfx906`` is the GPU architecture that the code is being compiled for. The supported GPU
 architectures can be found in the `AMDGPU Processor Table <https://llvm.org/docs/AMDGPUUsage.html#processors>`_.
 Alternatively, you can use the ``amdgpu-arch`` tool that comes with Clang to list the GPU architecture on your system:
 
 .. code-block:: shell
 
    amdgpu-arch
 
 You can use ``--offload-arch=native`` to automatically detect the GPU architectures on your system:
 
 .. code-block:: shell
 
-   clang++ --hip-link --offload-arch=native -xhip sample.cpp -o sample
+   clang++ --offload-arch=native -xhip sample.cpp -o sample
 
 
 Path Setting for Dependencies
 =============================
 
 Compiling a HIP program depends on the HIP runtime and device library. The paths to the HIP runtime and device libraries
 can be specified either using compiler options or environment variables. The paths can also be set through the ROCm path
 if they follow the ROCm installation directory structure.

clang/lib/Driver/ToolChains/CommonArgs.h

 void addFortranRuntimeLibs(const ToolChain &TC,
                            llvm::opt::ArgStringList &CmdArgs);
 
 /// Adds the path for the Fortran runtime libraries to \p CmdArgs.
 void addFortranRuntimeLibraryPath(const ToolChain &TC,
                                   const llvm::opt::ArgList &Args,
                                   llvm::opt::ArgStringList &CmdArgs);
 
-void addHIPRuntimeLibArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
+void addHIPRuntimeLibArgs(const ToolChain &TC, Compilation &C,
+                          const llvm::opt::ArgList &Args,
                           llvm::opt::ArgStringList &CmdArgs);
 
 const char *getAsNeededOption(const ToolChain &TC, bool as_needed);
 
 llvm::opt::Arg *getLastCSProfileGenerateArg(const llvm::opt::ArgList &Args);
 llvm::opt::Arg *getLastProfileUseArg(const llvm::opt::ArgList &Args);
 llvm::opt::Arg *getLastProfileSampleUseArg(const llvm::opt::ArgList &Args);
 

clang/lib/Driver/ToolChains/CommonArgs.cpp

for (StringRef LibraryPath : LibraryPaths) {
       }
     }
 
     if (!FoundBCLibrary)
       D.Diag(diag::err_drv_omp_offload_target_missingbcruntime)
           << LibOmpTargetName << ArchPrefix;
   }
 }
-void tools::addHIPRuntimeLibArgs(const ToolChain &TC,
+void tools::addHIPRuntimeLibArgs(const ToolChain &TC, Compilation &C,
                                  const llvm::opt::ArgList &Args,
                                  llvm::opt::ArgStringList &CmdArgs) {
-  if (Args.hasArg(options::OPT_hip_link) &&
+  if ((C.getActiveOffloadKinds() & Action::OFK_HIP) &&
       !Args.hasArg(options::OPT_nostdlib) &&
       !Args.hasArg(options::OPT_no_hip_rt)) {
     TC.AddHIPRuntimeLibArgs(Args, CmdArgs);
   } else {
     // Claim "no HIP libraries" arguments if any
     for (auto *Arg : Args.filtered(options::OPT_no_hip_rt)) {
       Arg->claim();
     }
   }
 }

clang/lib/Driver/ToolChains/Gnu.cpp

void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   if (Args.hasArg(options::OPT_Z_Xlinker__no_demangle))
     CmdArgs.push_back("--no-demangle");
 
   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
   bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
   addLinkerCompressDebugSectionsOption(ToolChain, Args, CmdArgs);
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
 
-  addHIPRuntimeLibArgs(ToolChain, Args, CmdArgs);
+  addHIPRuntimeLibArgs(ToolChain, C, Args, CmdArgs);
 
   // The profile runtime also needs access to system libraries.
   getToolChain().addProfileRTLibs(Args, CmdArgs);
 
   if (D.CCCIsCXX() &&
       !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
                    options::OPT_r)) {
     if (ToolChain.ShouldLinkCXXStdlib(Args)) {

clang/lib/Driver/ToolChains/MSVC.cpp

if (A.getOption().matches(options::OPT_l)) {
       continue;
     }
 
     // Otherwise, this is some other kind of linker input option like -Wl, -z,
     // or -L. Render it, even if MSVC doesn't understand it.
     A.renderAsInput(Args, CmdArgs);
   }
 
-  addHIPRuntimeLibArgs(TC, Args, CmdArgs);
+  addHIPRuntimeLibArgs(TC, C, Args, CmdArgs);
 
   TC.addProfileRTLibs(Args, CmdArgs);
 
   std::vector<const char *> Environment;
 
   // We need to special case some linker paths. In the case of the regular msvc
   // linker, we need to use a special search algorithm.
   llvm::SmallString<128> linkPath;

clang/test/Driver/hip-runtime-libs-linux.hip

 // RUN:   --rocm-path=%S/Inputs/rocm %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefixes=NOHIPRT %s
 
 // Test HIP runtime lib is not linked with -no-hip-rt.
 // RUN: %clang -### --hip-link -no-hip-rt --target=x86_64-linux-gnu \
 // RUN:   --rocm-path=%S/Inputs/rocm %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefixes=NOHIPRT %s
 
+// Test HIP runtime lib is linked without hip-link if there is HIP input file.
+// RUN: %clang -### --target=x86_64-linux-gnu -nogpuinc -nogpulib \
+// RUN:   --rocm-path=%S/Inputs/rocm %s 2>&1 \
+// RUN:   | FileCheck -check-prefixes=ROCM-PATH %s
+
 // ROCM-PATH: "-L[[HIPRT:.*/Inputs/rocm/lib]]" "-lamdhip64"
 // ROCM-RPATH: "-L[[HIPRT:.*/Inputs/rocm/lib]]" "-rpath" "[[HIPRT]]" "-lamdhip64"
 // ROCM-REL: "-L[[HIPRT:.*/opt/rocm-3.10.0/lib]]" "-lamdhip64"
 // NOHIPRT-NOT: "-L{{.*/Inputs/rocm/lib}}"
 // NOHIPRT-NOT: "-rpath" "{{.*/Inputs/rocm/lib}}"
 // NOHIPRT-NOT: "-lamdhip64"

clang/test/Driver/hip-runtime-libs-msvc.hip

 // REQUIRES: system-windows
 
 // RUN:  touch %t.o
 
 // Test HIP runtime lib args specified by --rocm-path.
 // RUN: %clang -### --hip-link --target=x86_64-pc-windows-msvc \
 // RUN:   --rocm-path=%S/Inputs/rocm %t.o 2>&1 \
 // RUN:   | FileCheck %s
 
+// Test HIP runtime lib is linked without --hip-link when there is HIP input file.
+// RUN: %clang -### --target=x86_64-pc-windows-msvc \
+// RUN:   --rocm-path=%S/Inputs/rocm %s 2>&1 \
+// RUN:   | FileCheck %s
+
 // CHECK: "-libpath:{{.*Inputs.*rocm.*lib}}" "amdhip64.lib"

clang/test/Driver/rocm-detect.hip

 // are found under HIP_PATH.
 
 // RUN: rm -rf %t/myhip
 // RUN: mkdir -p %t/myhip
 // RUN: cp -r %S/Inputs/rocm/bin %t/myhip
 
 // Test HIP_PATH overrides ROCM_PATH.
 // RUN: env ROCM_PATH=%S/Inputs/rocm HIP_PATH=%t/myhip \
-// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 --hip-link \
+// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 \
 // RUN:   --print-rocm-search-dirs %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=ROCM-ENV,HIP-PATH %s
 
 // Test --hip-path overrides ROCM_PATH.
 // RUN: env ROCM_PATH=%S/Inputs/rocm \
-// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 --hip-link \
+// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 \
 // RUN:   --hip-path=%t/myhip \
 // RUN:   --print-rocm-search-dirs %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=ROCM-ENV,HIP-PATH %s
 
 // Test --hip-path overrides --rocm-path.
-// RUN: %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 --hip-link \
+// RUN: %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 \
 // RUN:   --hip-path=%t/myhip --rocm-path=%S/Inputs/rocm \
 // RUN:   --print-rocm-search-dirs %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=ROCM-ENV,HIP-PATH %s
 
 // Test HIP_PATH overrides --rocm-path.
-// RUN: env HIP_PATH=%t/myhip %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 --hip-link \
+// RUN: env HIP_PATH=%t/myhip %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 \
 // RUN:   --rocm-path=%S/Inputs/rocm \
 // RUN:   --print-rocm-search-dirs %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=ROCM-ENV,HIP-PATH %s
 
 // Test empty HIP_PATH does not override --rocm-path.
 // RUN: env HIP_PATH= \
-// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 --hip-link \
+// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 \
 // RUN:   --rocm-path=%S/Inputs/rocm --print-rocm-search-dirs %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=ROCM-PATH %s
 
 // Test --hip-path option overrides environment variable HIP_PATH.
 
 // RUN: rm -rf %t/myhip
 // RUN: rm -rf %t/myhip_nouse
 // RUN: mkdir -p %t/myhip