[SYCL][Driver] Base libspirv path on sycl install candidates

... instead of the resource directory. This matches the behaviour of
SYCL device libraries. The resource directory has nothing to do with
libspirv, and it might be changed by the `-resource-dir` option, which
would lead us to not find it.

Author: Maetveis

clang/lib/Driver/ToolChains/SYCL.cpp

@@ -182,11 +182,9 @@ const char *SYCLInstallationDetector::findLibspirvPath(
   const SmallString<64> Basename =
       getLibSpirvBasename(DeviceTriple, HostTriple);
   auto searchAt = [&](StringRef Path, const Twine &a = "", const Twine &b = "",
-                      const Twine &c = "", const Twine &d = "",
-                      const Twine &e = "") -> const char * {
+                      const Twine &c = "") -> const char * {
     SmallString<128> LibraryPath(Path);
-    llvm::sys::path::append(LibraryPath, a, b, c, d);
-    llvm::sys::path::append(LibraryPath, e, Basename);
+    llvm::sys::path::append(LibraryPath, a, b, c, Basename);
 
     if (Args.hasArgNoClaim(options::OPT__HASH_HASH_HASH) ||
         llvm::sys::fs::exists(LibraryPath))
@@ -195,14 +193,15 @@ const char *SYCLInstallationDetector::findLibspirvPath(
     return nullptr;
   };
 
-  // Otherwise, assume libclc is installed at the same prefix as clang
-  // Expected path w/out install.
-  if (const char *R = searchAt(D.ResourceDir, "..", "..", "clc"))
-    return R;
+  for (const auto &IC : InstallationCandidates) {
+    // Expected path w/out install.
+    if (const char *R = searchAt(IC, "lib", "clc"))
+      return R;
 
-  // Expected path w/ install.
-  if (const char *R = searchAt(D.ResourceDir, "..", "..", "..", "share", "clc"))
-    return R;
+    // Expected path w/ install.
+    if (const char *R = searchAt(IC, "share", "clc"))
+      return R;
+  }
 
   return nullptr;
 }

clang/test/Driver/Inputs/SYCL/bin/.gitkeep

@@ -15,7 +15,7 @@
 // RUN: | FileCheck %s --check-prefixes=CHECK-LINUX
 // CHECK-LINUX: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "{{.*[\\/]}}remangled-l64-signed_char.libspirv-nvptx64-nvidia-cuda.bc"
 //
-// RUN: %clang -### -resource-dir %{resource_dir} -fsycl -fsycl-targets=amdgcn-amd-amdhsa -Xsycl-target-backend --offload-arch=gfx908 -nogpulib -target x86_64-unknown-windows-msvc %s 2>&1 \
+// RUN: %clang -### -ccc-install-dir %{install_dir} -fsycl -fsycl-targets=amdgcn-amd-amdhsa -Xsycl-target-backend --offload-arch=gfx908 -nogpulib -target x86_64-unknown-windows-msvc %s 2>&1 \
 // RUN: | FileCheck %s --check-prefixes=CHECK-AMDGCN-WINDOWS
 // CHECK-AMDGCN-WINDOWS: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "{{.*[\\/]}}remangled-l32-signed_char.libspirv-amdgcn-amd-amdhsa.bc"
 //
@@ -30,22 +30,22 @@
 // CHECK-CUDA: "-cc1"{{.*}} "-fcuda-is-device"
 // CHECK-CUDA-NOT: "-mlink-builtin-bitcode" "{{.*}}.libspirv-{{.*}}.bc"
 //
-// The path to the remangled libspirv bitcode file is determined by the resource directory.
+// The path to the remangled libspirv bitcode file is determined by the installation directory
 // RUN: %clang -### -ccc-install-dir %{install_dir}  -resource-dir %{resource_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib %s 2>&1 \
 // RUN: | FileCheck %s -DINSTALL_DIR=%{install_dir} -DRESOURCE_DIR=%{resource_dir} --check-prefixes=CHECK-DIR
-// CHECK-DIR: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "[[RESOURCE_DIR]]{{.*[\\/]}}remangled-{{.*}}.libspirv-nvptx64-nvidia-cuda.bc"
+// CHECK-DIR: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "[[INSTALL_DIR]]{{.*[\\/]}}remangled-{{.*}}.libspirv-nvptx64-nvidia-cuda.bc"
 //
 // The `-###` option disables file existence checks
 // DEFINE: %{nonexistent_dir} = %/S/Inputs/SYCL/does_not_exist/lib/clang/resource_dir
-// RUN: %clang -### -resource-dir %{nonexistent_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib %s 2>&1 \
-// RUN: | FileCheck %s     -DDIR=%{nonexistent_dir} --check-prefixes=CHECK-HHH-NONEXISTENT
+// RUN: %clang -### -ccc-install-dir %{nonexistent_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib %s 2>&1 \
+// RUN: | FileCheck %s         -DDIR=%{nonexistent_dir} --check-prefixes=CHECK-HHH-NONEXISTENT
 // CHECK-HHH-NONEXISTENT: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "[[DIR]]{{.*[\\/]}}remangled-{{.*}}.libspirv-nvptx64-nvidia-cuda.bc"
 //
-// RUN: %clang -### -resource-dir %{nonexistent_dir} -fsycl -fsycl-targets=amdgcn-amd-amdhsa -Xsycl-target-backend --offload-arch=gfx908 -nogpulib %s 2>&1 \
-// RUN: | FileCheck %s      -DDIR=%{nonexistent_dir} --check-prefixes=CHECK-AMDGCN-HHH-NONEXISTENT
+// RUN: %clang -### -ccc-install-dir %{nonexistent_dir} -fsycl -fsycl-targets=amdgcn-amd-amdhsa -Xsycl-target-backend --offload-arch=gfx908 -nogpulib %s 2>&1 \
+// RUN: | FileCheck %s         -DDIR=%{nonexistent_dir} --check-prefixes=CHECK-AMDGCN-HHH-NONEXISTENT
 // CHECK-AMDGCN-HHH-NONEXISTENT: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "[[DIR]]{{.*[\\/]}}remangled-{{.*}}.libspirv-amdgcn-amd-amdhsa.bc"
 //
 // `-fdriver-only` has no such special handling, so it will not find the file
-// RUN: not %clang -fdriver-only -resource-dir %{nonexistent_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib %s 2>&1 \
-// RUN: | FileCheck %s --check-prefixes=CHECK-DO-NONEXISTENT
+// RUN: not %clang -fdriver-only -ccc-install-dir %{nonexistent_dir} -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib %s 2>&1 \
+// RUN: | FileCheck %s                      -DDIR=%{nonexistent_dir} --check-prefixes=CHECK-DO-NONEXISTENT
 // CHECK-DO-NONEXISTENT: error: cannot find 'remangled-{{.*}}.libspirv-nvptx64-nvidia-cuda.bc'; provide path to libspirv library via '-fsycl-libspirv-path', or pass '-fno-sycl-libspirv' to build without linking with libspirv