[Misc] Strictly check ndim with external array (taichi-dev#7126)

Issue: taichi-dev#6572 

* Check external ndarray total dim against type annotation
* Error out when element shape mismatch
* Refine error messages

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

docs/lang/articles/get-started/accelerate_pytorch.md

@@ -180,9 +180,9 @@ The Taichi reference code is almost identical to its Python counterpart. And a g
 ```python
 @ti.kernel
 def taichi_forward_v0(
-        out: ti.types.ndarray(field_dim=3),
-        w: ti.types.ndarray(field_dim=3),
-        k: ti.types.ndarray(field_dim=3),
+        out: ti.types.ndarray(ndim=3),
+        w: ti.types.ndarray(ndim=3),
+        k: ti.types.ndarray(ndim=3),
         eps: ti.f32):
 
     for b, c, t in out:

python/taichi/lang/_ndarray.py

@@ -137,7 +137,7 @@ def _ndarray_matrix_from_numpy(self, arr, as_vector):
             raise TypeError(f"{np.ndarray} expected, but {type(arr)} provided")
         if tuple(self.arr.total_shape()) != tuple(arr.shape):
             raise ValueError(
-                f"Mismatch shape: {tuple(self.arr.shape)} expected, but {tuple(arr.shape)} provided"
+                f"Mismatch shape: {tuple(self.arr.total_shape())} expected, but {tuple(arr.shape)} provided"
             )
         if not arr.flags.c_contiguous:
             arr = np.ascontiguousarray(arr)

python/taichi/lang/kernel_impl.py

@@ -410,11 +410,30 @@ def extract_arg(arg, anno):
             shape = tuple(shape)
             element_shape = ()
             if isinstance(anno.dtype, MatrixType):
-                if len(shape) < anno.dtype.ndim:
-                    raise ValueError(
-                        f"Invalid argument into ti.types.ndarray() - required element_dim={anno.dtype.ndim}, "
-                        f"but the argument has only {len(shape)} dimensions")
+                if anno.ndim is not None:
+                    if len(shape) != anno.dtype.ndim + anno.ndim:
+                        raise ValueError(
+                            f"Invalid argument into ti.types.ndarray() - required array has ndim={anno.ndim} element_dim={anno.dtype.ndim}, "
+                            f"but the argument has {len(shape)} dimensions")
+                else:
+                    if len(shape) < anno.dtype.ndim:
+                        raise ValueError(
+                            f"Invalid argument into ti.types.ndarray() - required element_dim={anno.dtype.ndim}, "
+                            f"but the argument has only {len(shape)} dimensions"
+                        )
                 element_shape = shape[-anno.dtype.ndim:]
+                anno_element_shape = anno.dtype.get_shape()
+                if None not in anno_element_shape and element_shape != anno_element_shape:
+                    raise ValueError(
+                        f"Invalid argument into ti.types.ndarray() - required element_shape={anno_element_shape}, "
+                        f"but the argument has element shape of {element_shape}"
+                    )
+            elif anno.dtype is not None:
+                # User specified scalar dtype
+                if anno.ndim is not None and len(shape) != anno.ndim:
+                    raise ValueError(
+                        f"Invalid argument into ti.types.ndarray() - required array has ndim={anno.ndim}, "
+                        f"but the argument has {len(shape)} dimensions")
             return to_taichi_type(
                 arg.dtype), len(shape), element_shape, Layout.AOS
         if isinstance(anno, sparse_matrix_builder):

tests/python/test_ndarray.py

@@ -483,9 +483,6 @@ def func(a: ti.types.ndarray(ti.types.vector(n=10, dtype=ti.i32))):
     v = np.zeros((6, 10), dtype=np.int32)
     func(v)
     assert impl.get_runtime().get_num_compiled_functions() == 1
-    v = np.zeros((6, 11), dtype=np.int32)
-    func(v)
-    assert impl.get_runtime().get_num_compiled_functions() == 2
 
 
 @test_utils.test(arch=supported_archs_taichi_ndarray)

tests/python/test_numpy.py

@@ -249,3 +249,44 @@ def fill(img: ti.types.ndarray()):
     with pytest.raises(ValueError,
                        match='Non contiguous numpy arrays are not supported'):
         fill(a)
+
+
+@test_utils.test()
+def test_numpy_ndarray_dim_check():
+    @ti.kernel
+    def add_one_mat(arr: ti.types.ndarray(dtype=ti.math.mat3, ndim=2)):
+        for i in ti.grouped(arr):
+            arr[i] = arr[i] + 1.0
+
+    @ti.kernel
+    def add_one_scalar(arr: ti.types.ndarray(dtype=ti.f32, ndim=2)):
+        for i in ti.grouped(arr):
+            arr[i] = arr[i] + 1.0
+
+    a = np.zeros(shape=(2, 2, 3, 3), dtype=np.float32)
+    b = np.zeros(shape=(2, 2, 2, 3), dtype=np.float32)
+    c = np.zeros(shape=(2, 2, 3), dtype=np.float32)
+    d = np.zeros(shape=(2, 2), dtype=np.float32)
+    add_one_mat(a)
+    add_one_scalar(d)
+    np.testing.assert_allclose(a, np.ones(shape=(2, 2, 3, 3),
+                                          dtype=np.float32))
+    np.testing.assert_allclose(d, np.ones(shape=(2, 2), dtype=np.float32))
+    with pytest.raises(
+            ValueError,
+            match=
+            r'Invalid argument into ti.types.ndarray\(\) - required element_shape=\(.*\), but the argument has element shape of \(.*\)'
+    ):
+        add_one_mat(b)
+    with pytest.raises(
+            ValueError,
+            match=
+            r'Invalid argument into ti.types.ndarray\(\) - required array has ndim=2 element_dim=2, but the argument has 3 dimensions'
+    ):
+        add_one_mat(c)
+    with pytest.raises(
+            ValueError,
+            match=
+            r'Invalid argument into ti.types.ndarray\(\) - required array has ndim=2, but the argument has 4 dimensions'
+    ):
+        add_one_scalar(a)