[mlir][python] expose the shape property of shaped types

[ftynse]

Summary

This has been missing in the original definition of shaped types.

[gysit]

LGTM!

mlir/lib/Bindings/Python/IRTypes.cpp

static void bindDerived(ClassTy &c) {
     c.def(
         "is_dynamic_stride_or_offset",
         [](PyShapedType &self, int64_t val) -> bool {
           self.requireHasRank();
           return mlirShapedTypeIsDynamicStrideOrOffset(val);
         },
         "Returns whether the given value is used as a placeholder for dynamic "
         "strides and offsets in shaped types.");
+    c.def_property_readonly(
+        "shape",
+        [](PyShapedType &self) {
+          self.requireHasRank();
+
+          std::vector<int64_t> shape;
+          int64_t rank = mlirShapedTypeGetRank(self);
+          shape.reserve(rank);
+          for (int64_t i = 0; i < rank; ++i)
+            shape.push_back(mlirShapedTypeGetDimSize(self, i));
+          return shape;
+        },
+        "Returns the shape of the ranked shaped type as a list of integers.");
   }
 
 private:
   void requireHasRank() {
     if (!mlirShapedTypeHasRank(*this)) {
       throw SetPyError(
           PyExc_ValueError,
           "calling this method requires that the type has a rank.");

mlir/test/python/ir/builtin_types.py

except ValueError as e:
       # CHECK: or complex type.
       print(e)
     else:
       print("Exception not produced")
 
     # Encoding should be None.
     assert RankedTensorType.get(shape, f32).encoding is None
 
+    tensor = RankedTensorType.get(shape, f32)
+    assert tensor.shape == shape
+
 
 # CHECK-LABEL: TEST: testUnrankedTensorType
 @run
 def testUnrankedTensorType():
   with Context(), Location.unknown():
     f32 = F32Type.get()
     loc = Location.unknown()
     unranked_tensor = UnrankedTensorType.get(f32)
try:
       memref_invalid = MemRefType.get(shape, none)
     except ValueError as e:
       # CHECK: invalid 'Type(none)' and expected floating point, integer, vector
       # CHECK: or complex type.
       print(e)
     else:
       print("Exception not produced")
 
+    assert memref.shape == shape
+
 
 # CHECK-LABEL: TEST: testUnrankedMemRefType
 @run
 def testUnrankedMemRefType():
   with Context(), Location.unknown():
     f32 = F32Type.get()
     loc = Location.unknown()
     unranked_memref = UnrankedMemRefType.get(f32, Attribute.parse("2"))