[SYCL][Driver] Improve SYCL libspirv linking test coverage (NFC) (#19130)

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# Based on PR #18956

## Tree of downstream PRs as of 2025-06-25

* **PR #19130 (THIS ONE)**

    * PR #19131

      * PR #19134

        * PR #19135

          * PR #19136

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In the next commits I'd like to refactor and fix SYCL libspirv linking.
This adds a few tests to cover the current behavior. Some of it is
buggy, and not consistent between NVPTX and AMDGPU, it will be improved
in the next commits.

Author: Maetveis

clang/test/Driver/Inputs/SYCL/lib/nvidiacl/remangled-l32-signed_char.libspirv-nvptx64--nvidiacl.bc renamed to clang/test/Driver/Inputs/SYCL/lib/clang/resource_dir/.gitkeep

@@ -0,0 +1,49 @@
+// Test the search logic for the libspirv bitcode library in the offloading toolchains that need it.
+
+// DEFINE: %{install_dir}  = %/S/Inputs/SYCL/bin
+// DEFINE: %{resource_dir} = %/S/Inputs/SYCL/lib/clang/resource_dir
+
+// RUN: %clang -### -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib -target x86_64-unknown-windows-msvc %s 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-WINDOWS
+// CHECK-WINDOWS: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "{{.*[\\/]}}remangled-l32-signed_char.libspirv-nvptx64-nvidia-cuda.bc"
+//
+// RUN: %clang -### -fsycl -fsycl-targets=nvptx64-nvidia-cuda -nocudalib -target x86_64-unknown-linux-gnu %s 2>&1 \
+// 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"
+//
+// AMDGCN wrongly uses 32-bit longs on Windows
+// 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: | FileCheck %s --check-prefixes=CHECK-AMDGCN-WINDOWS
+// CHECK-AMDGCN-WINDOWS: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "{{.*[\\/]}}remangled-l64-signed_char.libspirv-amdgcn-amd-amdhsa.bc"
+//
+// RUN: %clang -### -fsycl -fsycl-device-only -fsycl-targets=nvptx64-nvidia-cuda -nocudalib %s 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-DEVICE-ONLY
+// CHECK-DEVICE-ONLY: "-cc1"{{.*}} "-fsycl-is-device"
+// CHECK-DEVICE-ONLY-NOT: "-mlink-builtin-bitcode" "{{.*}}.libspirv-{{.*}}.bc"
+//
+// Only link libspirv in SYCL language mode, but `-fno-sycl-libspirv` does not result in a warning
+// RUN: %clang -### -x cu -fno-sycl-libspirv -nocudainc -nocudalib %s 2>&1 | FileCheck %s --check-prefixes=CHECK-CUDA
+// CHECK-CUDA-NOT: warning: argument unused during compilation: '-fno-sycl-libspirv' [-Wunused-command-line-argument]
+// 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.
+// 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"
+//
+// 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
+// CHECK-HHH-NONEXISTENT: "-cc1"{{.*}} "-fsycl-is-device"{{.*}} "-mlink-builtin-bitcode" "[[DIR]]{{.*[\\/]}}remangled-{{.*}}.libspirv-nvptx64-nvidia-cuda.bc"
+//
+// But not for AMDGCN :^)
+// RUN: not %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
+// CHECK-AMDGCN-HHH-NONEXISTENT: error: cannot find 'remangled-{{.*}}.libspirv-amdgcn-amd-amdhsa.bc'; provide path to libspirv library via '-fsycl-libspirv-path', or pass '-fno-sycl-libspirv' to build without linking with libspirv
+//
+// `-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
+// 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

clang/test/Driver/Inputs/SYCL/lib/nvidiacl/remangled-l64-signed_char.libspirv-nvptx64--nvidiacl.bc renamed to clang/test/Driver/Inputs/SYCL/share/clc/remangled-l32-signed_char.libspirv-amdgcn-amd-amdhsa.bc

@@ -38,7 +38,7 @@
 // RUN: %clangxx -ccc-print-phases --sysroot=%S/Inputs/SYCL -std=c++11 \
 // RUN: -target x86_64-unknown-linux-gnu -fsycl -fno-sycl-device-lib=all \
 // RUN: -fsycl-instrument-device-code -fsycl-targets=nvptx64-nvidia-cuda %s 2>&1 \
-// RUN: -fsycl-libspirv-path=%S/Inputs/SYCL/lib/nvidiacl \
+// RUN: -fsycl-libspirv-path=%S/Inputs/SYCL/share/clc/remangled-l32-signed_char.libspirv-nvptx64-nvidia-cuda.bc \
 // RUN: --cuda-path=%S/Inputs/CUDA_111/usr/local/cuda \
 // RUN: | FileCheck -check-prefix=CHK-PHASES-NO-CC %s
 //
@@ -57,7 +57,7 @@
 // CHK-PHASES-NO-CC: 10: input, "{{.*}}libsycl-itt-user-wrappers.bc", ir, (device-sycl, sm_50)
 // CHK-PHASES-NO-CC: 11: input, "{{.*}}libsycl-itt-compiler-wrappers.bc", ir, (device-sycl, sm_50)
 // CHK-PHASES-NO-CC: 12: input, "{{.*}}libsycl-itt-stubs.bc", ir, (device-sycl, sm_50)
-// CHK-PHASES-NO-CC: 13: input, "{{.*}}nvidiacl{{.*}}", ir, (device-sycl, sm_50)
+// CHK-PHASES-NO-CC: 13: input, "{{.*}}libspirv-nvptx64{{.*}}", ir, (device-sycl, sm_50)
 // CHK-PHASES-NO-CC: 14: input, "{{.*}}libdevice{{.*}}", ir, (device-sycl, sm_50)
 // CHK-PHASES-NO-CC: 15: linker, {9, 10, 11, 12, 13, 14}, ir, (device-sycl, sm_50)
 // CHK-PHASES-NO-CC: 16: sycl-post-link, {15}, ir, (device-sycl, sm_50)
@@ -75,7 +75,7 @@
 // RUN: %clangxx -ccc-print-phases --sysroot=%S/Inputs/SYCL -std=c++11 \
 // RUN: -target x86_64-unknown-linux-gnu -fsycl -fno-sycl-device-lib=all \
 // RUN: -fsycl-instrument-device-code -fsycl-targets=nvptx64-nvidia-cuda \
-// RUN: -fsycl-libspirv-path=%S/Inputs/SYCL/lib/nvidiacl \
+// RUN: -fsycl-libspirv-path=%S/Inputs/SYCL/share/clc/remangled-l32-signed_char.libspirv-nvptx64-nvidia-cuda.bc \
 // RUN: --cuda-path=%S/Inputs/CUDA_111/usr/local/cuda \
 // RUN: -Xsycl-target-backend "--cuda-gpu-arch=sm_35" %s 2>&1 \
 // RUN: | FileCheck -check-prefix=CHK-PHASES %s
@@ -95,7 +95,7 @@
 // CHK-PHASES: 10: input, "{{.*}}libsycl-itt-user-wrappers.bc", ir, (device-sycl, sm_35)
 // CHK-PHASES: 11: input, "{{.*}}libsycl-itt-compiler-wrappers.bc", ir, (device-sycl, sm_35)
 // CHK-PHASES: 12: input, "{{.*}}libsycl-itt-stubs.bc", ir, (device-sycl, sm_35)
-// CHK-PHASES: 13: input, "{{.*}}nvidiacl{{.*}}", ir, (device-sycl, sm_35)
+// CHK-PHASES: 13: input, "{{.*}}libspirv-nvptx64{{.*}}", ir, (device-sycl, sm_35)
 // CHK-PHASES: 14: input, "{{.*}}libdevice{{.*}}", ir, (device-sycl, sm_35)
 // CHK-PHASES: 15: linker, {9, 10, 11, 12, 13, 14}, ir, (device-sycl, sm_35)
 // CHK-PHASES: 16: sycl-post-link, {15}, ir, (device-sycl, sm_35)