[Mlir-commits] [mlir] [mlir][python] expose remaining Location inspection API (PR #192630)

[Soowon Jeong]

================
@@ -1164,6 +1168,122 @@ class MLIR_PYTHON_API_EXPORTED PyStringAttribute
   static void bindDerived(ClassTy &c);
 };
 
+/// CRTP base class for Python classes that subclass Location and should be
+/// castable from it (i.e. via something like FileLineColLoc(loc)).
+template <typename DerivedTy, typename BaseTy = PyLocation>
+class MLIR_PYTHON_API_EXPORTED PyConcreteLocation : public BaseTy {
+public:
+  // Derived classes must define statics for:
+  //   IsAFunctionTy isaFunction
+  //   const char *pyClassName
+  using ClassTy = nanobind::class_<DerivedTy, BaseTy>;
+  using IsAFunctionTy = bool (*)(MlirLocation);
+  using GetTypeIDFunctionTy = MlirTypeID (*)();
+  static constexpr GetTypeIDFunctionTy getTypeIdFunction = nullptr;
+  using Base = PyConcreteLocation;
+
+  PyConcreteLocation() = default;
+  PyConcreteLocation(PyMlirContextRef contextRef, MlirLocation loc)
+      : BaseTy(std::move(contextRef), loc) {}
+  PyConcreteLocation(PyLocation &orig)
+      : PyConcreteLocation(orig.getContext(), castFrom(orig)) {}
+
+  static MlirLocation castFrom(PyLocation &orig) {
+    if (!DerivedTy::isaFunction(orig.get())) {
+      auto origRepr =
+          nanobind::cast<std::string>(nanobind::repr(nanobind::cast(orig)));
+      throw nanobind::value_error((std::string("Cannot cast location to ") +
+                                   DerivedTy::pyClassName + " (from " +
+                                   origRepr + ")")
+                                      .c_str());
+    }
+    return orig.get();
+  }
+
----------------
swjng wrote:

Done in a1f6541. Mirrored the `PyConcreteAttribute` `__repr__` pattern; also added `__str__` on the base `Location` (assembly form) so `str()` keeps producing the assembly form regardless of subclass, same split as `Attribute`/`PyConcreteAttribute`.

https://github.com/llvm/llvm-project/pull/192630