[backport] Add import test without CUDA Toolkit

.pfnci/linux/tests/cuda-build.sh

@@ -18,8 +18,8 @@ export CUPY_NVCC_GENERATE_CODE="arch=compute_70,code=sm_70"
 
 # Make sure that CuPy can be imported without CUDA Toolkit installed.
 rm -rf /usr/local/cuda*
-pushd /
-python3 -c 'import cupy, cupyx; cupy.show_config(_full=True)'
+pushd tests/import_tests
+python3 test_import.py
 popd
 
 "$ACTIONS/cleanup.sh"

tests/import_tests/test_import.py

@@ -0,0 +1,50 @@
+import cupy
+from cupyx import jit
+
+"""
+Test to ensure that this file can be imported without CUDA Toolkit.
+"""
+
+
+@cupy.memoize()
+def user_func(a: cupy.ndarray):
+    a.sum()
+
+
+squared_diff = cupy.ElementwiseKernel(
+    'float32 x, float32 y',
+    'float32 z',
+    'z = (x - y) * (x - y)',
+    'squared_diff')
+
+
+l2norm_kernel = cupy.ReductionKernel(
+    'T x',  # input params
+    'T y',  # output params
+    'x * x',  # map
+    'a + b',  # reduce
+    'y = sqrt(a)',  # post-reduction map
+    '0',  # identity value
+    'l2norm'  # kernel name
+)
+
+complex_kernel = cupy.RawKernel(r'''
+#include <cupy/complex.cuh>
+extern "C" __global__
+void my_func(const complex<float>* x1, const complex<float>* x2,
+             complex<float>* y, float a) {
+    int tid = blockDim.x * blockIdx.x + threadIdx.x;
+    y[tid] = x1[tid] + a * x2[tid];
+}
+''', 'my_func')
+
+
+@jit.rawkernel()
+def elementwise_copy(x, y, size):
+    tid = jit.blockIdx.x * jit.blockDim.x + jit.threadIdx.x
+    ntid = jit.gridDim.x * jit.blockDim.x
+    for i in range(tid, size, ntid):
+        y[i] = x[i]
+
+
+cupy.show_config(_full=True)