[HIP] Supports env var HIP_PATH

[yaxunl]

Summary

Currently HIP toolchain recognize env var ROCM_PATH and option --rocm-path
but only recognize --hip-path.

Some package management tools e.g. Spack relies on env var HIP_PATH to
be able to load different version of HIP dynamically.
(https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/hip/package.py#L446)
Therefore add support of env var HIP_PATH.

[tra]

clang/lib/Driver/ToolChains/AMDGPU.cpp

442

Style nit. Single-statement if body should be w/o {}.

[MaskRay]

clang/test/Driver/rocm-detect.hip

42

%T is not recommended.

https://llvm.org/docs/CommandGuide/lit.html
"parent directory of %t (not unique, deprecated, do not use)"

Just use RUN: rm -rf %t && mkdir %t

[yaxunl]

clang/lib/Driver/ToolChains/AMDGPU.cpp

442

will fix

clang/test/Driver/rocm-detect.hip

42

I will use %t/myhip, as I need a deterministic unique name to check that it is used

[yaxunl]

fix tests

[yaxunl]

ping

clang/lib/Driver/ToolChains/AMDGPU.cpp

if (HasDeviceLibrary)
       return;
   }
 }
 
 void RocmInstallationDetector::detectHIPRuntime() {
   SmallVector<Candidate, 4> HIPSearchDirs;
   if (!HIPPathArg.empty())
     HIPSearchDirs.emplace_back(HIPPathArg.str(), /*StrictChecking=*/true);
-  else
+  else if (std::optional<std::string> HIPPathEnv =
+               llvm::sys::Process::GetEnv("HIP_PATH")) {
+    if (!HIPPathEnv->empty())
+      HIPSearchDirs.emplace_back(std::move(*HIPPathEnv));
+  } else
     HIPSearchDirs.append(getInstallationPathCandidates());
   auto &FS = D.getVFS();
 
   for (const auto &Candidate : HIPSearchDirs) {
     InstallPath = Candidate.Path;
     if (InstallPath.empty() || !FS.exists(InstallPath))
       continue;
     // HIP runtime built by SPACK is installed to

clang/test/Driver/rocm-detect.hip

 // RUN:   --rocm-path=%S/Inputs/rocm %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=COMMON,NODEFAULTLIBS %s
 
 // Test environment variable ROCM_PATH.
 // RUN: env ROCM_PATH=%S/Inputs/rocm %clang -### -target x86_64-linux-gnu \
 // RUN:   --print-rocm-search-dirs %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=ROCM-ENV %s
 
+// Test interaction between environment variables HIP_PATH and ROCM_PATH.
+// Device libs are found under ROCM_PATH. HIP include files and HIP runtime library
+// are found under HIP_PATH.
+
+// RUN: rm -rf %t/myhip
+// RUN: mkdir -p %t/myhip
+// RUN: cp -r %S/Inputs/rocm/bin %t/myhip
+// RUN: env ROCM_PATH=%S/Inputs/rocm HIP_PATH=%t/myhip \
+// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 --hip-link \
+// RUN:   --print-rocm-search-dirs %s 2>&1 \
+// RUN:   | FileCheck -check-prefixes=ROCM-ENV,HIP-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
+// RUN: mkdir -p %t/myhip_nouse
+// RUN: cp -r %S/Inputs/rocm/bin %t/myhip
+// RUN: cp -r %S/Inputs/rocm/bin %t/myhip_nouse
+// RUN: env ROCM_PATH=%S/Inputs/rocm HIP_PATH=%t/myhip_nouse \
+// RUN:   %clang -### -target x86_64-linux-gnu --offload-arch=gfx1010 --hip-link \
+// RUN:   --hip-path=%t/myhip --print-rocm-search-dirs %s 2>&1 \
+// RUN:   | FileCheck -check-prefixes=ROCM-ENV,HIP-PATH %s
+
 // Test detecting latest /opt/rocm-{release} directory.
 // RUN: rm -rf %T/opt
 // RUN: mkdir -p %T/opt
 // RUN: cp -r %S/Inputs/rocm %T/opt/rocm-3.9.0-1234
 // RUN: cp -r %S/Inputs/rocm %T/opt/rocm-3.10.0
 // RUN: %clang -### -target x86_64-linux-gnu --sysroot=%T \
 // RUN:   --print-rocm-search-dirs %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=ROCM-REL %s

 // RUN:   | FileCheck -check-prefixes=SPACK-MISS-SILENT %s
 
 // GFX902-DEFAULTLIBS: error: cannot find ROCm device library for gfx902; provide its path via '--rocm-path' or '--rocm-device-lib-path', or pass '-nogpulib' to build without ROCm device library
 
 // NODEFAULTLIBS-NOT: error: cannot find
 
 // COMMON: "-triple" "amdgcn-amd-amdhsa"
 
-// ROCM-ENV: ROCm installation search path: {{.*}}/Inputs/rocm
+// ROCM-ENV: ROCm installation search path: [[ROCM_PATH:.*/Inputs/rocm]]
+
+// HIP-PATH: "-mlink-builtin-bitcode" "[[ROCM_PATH]]/amdgcn/bitcode/oclc_isa_version_1010.bc"
+// HIP-PATH: "-idirafter" "[[HIP_PATH:.*/myhip]]/include"
+// HIP-PATH: "-L[[HIP_PATH]]/lib" "-lamdhip64"
 
 // ROCM-REL: ROCm installation search path: {{.*}}/opt/rocm
 // ROCM-REL: ROCm installation search path: {{.*}}/opt/rocm-3.10.0
 
 // SPACK: InstalledDir: [[DIR:.*]]/llvm-amdgpu-4.0.0-ieagcs7inf7runpyfvepqkurasoglq4z/bin
 // SPACK: ROCm installation search path (Spack 4.0.0): [[DIR]]
 // SPACK: ROCm installation search path: [[CLANG:.*]]
 // SPACK: ROCm installation search path: [[DIR]]/llvm-amdgpu-4.0.0-ieagcs7inf7runpyfvepqkurasoglq4z