Fix dir() method

[markcmiller86]

Description

Resolves #19264

• Adds a custom __dir__() method to our python objects which lists all methods in the _methods[] table (except __dir__ and Notify) as well as all non-internal data members
  • For an example of an object that has internal members, look at the dir() method in PySpreadsheetAttributes.C
• Adds _methods table pointer to the tp_methods slot of the object header
• Changes Notify to METH_NOARGS in the _methods[] table
• Increases _NMETH by one (which causes all associated .h files to change too)
• Improves behavior of apropos

Type of change

• Bug fix~~
• [~~ ] New feature~~
• [ ] Documentation update
• [ ] Other

How Has This Been Tested?

Reminders:

• Please follow the style guidelines of this project.
• Please perform a self-review of your code before submitting a PR and asking others to review it.
• Please assign reviewers (see VisIt's PR procedures for more information).

Checklist:

• I have commented my code where applicable.~~
• I have updated the release notes.~~
• I have made corresponding changes to the documentation.~~
• I have added debugging support to my changes.~~
• I have added tests that prove my fix is effective or that my feature works.~~
• I have confirmed new and existing unit tests pass locally with my changes.~~
• I have added new baselines for any new tests to the repo.~~
• I have NOT made any changes to protocol or public interfaces in an RC branch.~~

[markcmiller86]

I've discovered from other changes I need to make here. isinstance(x, str) was generating a ValueError exception due to no __class__ attribute. I think the solution is that we need to switch from getattr/setattr to getattro/setattro. I am testing on one object and it seems to be behaving better.

[markcmiller86]

@visit-dav/visit-developers and @cyrush can you please have a look at the direction this is headed and lemme know what you think. There are 3 key things to look at here...

• Py2and3support.h macros for handling python objects. I've tried a few different approaches here and am settling on this. That said, there is a far nicer approach if we are willing to require C++ designated initializers (a C++ 20 standard but available far sooner in many compilers).

  • visit/src/visitpy/common/Py2and3Support.h

    Lines 290 to 402 in 7c6987a

    	// Mark C. Miller, Wed Mar 26 18:58:25 PDT 2025
    	// These macros are used within the definition of VISIT_PY_TYPE_OBJ to help
    	// build a block of code representing the default set of .tp_xxx slot methods
    	// our standard objects need to define. Its likely overly cautious but the reason
    	// for the funky retval incrimenting here is to ensure there is no way any compiler
    	// optimizations could maybe decide the function in which this code block appears
    	// could ever be optimized away because its return value could maybe be computed at
    	// compile time.
    	//
    	// We make prolific use of the CPP paste operator (##) here to enforce naming
    	// consistency.
    	//
    	#define VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, SLOT) \
    	Py##VSObjName##Type.tp_##SLOT = Py##VSObjName##_##SLOT; \
    	retval += ((void*) Py##VSObjName##Type.tp_##SLOT != (void*)0)
    	#define VISIT_PY_TYPE_OBJ_SLOT2(VSObjName, SLOT, FUNC) \
    	Py##VSObjName##Type.tp_##SLOT = Py##VSObjName##_##FUNC; \
    	retval += ((void*) Py##VSObjName##Type.tp_##SLOT != (void*)0)
    	//
    	// For non-standard objects, the correct approach is to #undef this macro and
    	// then re-define it to what is needed AHEAD of invoking VISIT_PY_TYPE_OBJ().
    	//
    	#define VISIT_PY_TYPE_OBJ_TP_SLOTS(VSObjName) \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, dealloc); \
    	VISIT_PY_TYPE_OBJ_SLOT2(VSObjName, repr, str); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, str); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, getattro); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, setattro); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, richcompare); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, methods)
    	// 2023/01/27 CYRUSH Note:
    	// tp_print / tp_vectorcall_offset slot is not used by python 3.0 - 3.7
    	// it should not be used for python 3.8 > unless Py_TPFLAGS_HAVE_VECTORCALL
    	// is passed, but we choose to always set to 0
    	//
    	// Also we use VPY_STR to implement both str() and repr(), as this
    	// preserves the Python 2 cli behavior to echo object contents via repr()
    	//
    	// Mark C. Miller, Mon Mar 24 16:07:55 PDT 2025
    	// Adjust VISIT_PY_TYPE_OBJ to initialize our python objects in two steps.
    	// The first is an *assignment* of the PyTypeObject struct with mostly zero
    	// entries and other critical boilerplate stuff. The second is the assignment
    	// to a dummy static variable of the result of calling a static initialization
    	// function for the type. It is in that function where the remaining .tp_xxx
    	// slots are set up according to the (above) VISIT_PY_TYPE_OBJ_TP_SLOTS macro.
    	// To override the default behavior, simply #undef VISIT_PY_TYPE_OBJ_TP_SLOTS
    	// and then re-define it to what is needed before invoking VISIT_PY_TYPE_OBJ.
    	//
    	// We make prolific use of the CPP paste operator (##) here to enforce naming
    	// consistency.
    	//
    	#define VISIT_PY_TYPE_OBJ(VSObjName) \
    	static PyTypeObject Py##VSObjName##Type = \
    	{ \
    	PyVarObject_HEAD_INIT(&PyType_Type, 0) \
    	#VSObjName, /* tp_name */ \
    	sizeof(Py##VSObjName##Object),/* tp_basicsize */ \
    	0, /* tp_itemsize */ \
    	0, /* tp_dealloc */ \
    	0, /* tp_print (py2 and < py3.8)... */ \
    	/* ...or tp_vectorcall_offset (>py3.8 */ \
    	0, /* tp_getattr */ \
    	0, /* tp_setattr */ \
    	0, /* tp_reserved */ \
    	0, /* tp_repr */ \
    	0, /* tp_as_number */ \
    	0, /* tp_as_sequence */ \
    	0, /* tp_as_mapping */ \
    	0, /* tp_hash */ \
    	0, /* tp_call */ \
    	0, /* tp_str */ \
    	0, /* tp_getattro */ \
    	0, /* tp_setattro */ \
    	0, /* tp_as_buffer */ \
    	PY_VISIT_TPFLAGS_DEFAULT, /* tp_flags */ \
    	Py##VSObjName##_purpose, /* tp_doc */ \
    	0, /* tp_traverse */ \
    	0, /* tp_clear */ \
    	0, /* tp_richcompare */ \
    	0, /* tp_weaklistoffset */ \
    	0, /* tp_iter */ \
    	0, /* tp_iternext */ \
    	0, /* tp_methods */ \
    	0, /* tp_members */ \
    	0, /* tp_getset */ \
    	0, /* tp_base */ \
    	0, /* tp_dict */ \
    	0, /* tp_descr_get */ \
    	0, /* tp_descr_set */ \
    	0, /* tp_dictoffset */ \
    	0, /* tp_init */ \
    	0, /* tp_alloc */ \
    	0, /* tp_new */ \
    	0, /* tp_free */ \
    	0, /* tp_is_gc */ \
    	0, /* tp_bases */ \
    	0, /* tp_mro */ \
    	0, /* tp_cache */ \
    	0, /* tp_subclasses */ \
    	0, /* tp_weaklist */ \
    	0, /* tp_del */ \
    	0 /* tp_version_tag */ \
    	PyVarObject_TAIL \
    	}; \
    	static int VSObjName##_init(void) { \
    	static int retval = 0; \
    	VISIT_PY_TYPE_OBJ_TP_SLOTS(VSObjName); \
    	return retval; \
    	} \
    	static int VSObjName##_initialized = VSObjName##_init()

• An example standard object (fully code-gened)...

  • visit/src/plots/Pseudocolor/PyPseudocolorAttributes.C

    Lines 4130 to 4136 in 7c6987a

    	//
    	// Initialize the python object type structure with default values.
    	// If you need to do something custom, #undef VISIT_PY_TYPE_OBJ_TP_SLOTS,
    	// and then re-define it here AHEAD of VISIT_PY_TYPE_OBJ. For examples, look
    	// in src/avt/PythonFilters and in src/visitpy/common/Py2and3Support.h
    	//
    	VISIT_PY_TYPE_OBJ(PseudocolorAttributes);

• An example of a custom object (manually written)...

  • visit/src/visitpy/visitpy/PyView3DAttributes.C

    Lines 1381 to 1392 in fcb359e

    	// Re-define tp slots for this custom object
    	#undef VISIT_PY_TYPE_OBJ_TP_SLOTS
    	#define VISIT_PY_TYPE_OBJ_TP_SLOTS(VSObjName) \
    	VISIT_PY_TYPE_OBJ_SLOT2(VSObjName, doc, purpose); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, dealloc); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, getattro); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, setattro); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, str); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, richcompare); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, as_number); \
    	VISIT_PY_TYPE_OBJ_SLOT1(VSObjName, methods)
    	VISIT_PY_TYPE_OBJ(View3DAttributes);

[biagas]

The setattro/getattro will still allow custom logic for handling old settings? (As is currently done for VolumePlot)?

You will be verifying the test suite, correct?

[biagas]

Might want to change the function names in the comments to match new names.

[markcmiller86]

The setattro/getattro will still allow custom logic for handling old settings? (As is currently done for VolumePlot)?

Not sure what you mean. set/getattro is the python 3 way to do set/getattr. Same function bodies. Slightly different call signatures.

You will be verifying the test suite, correct?

Well, if I must 🤔.

[biagas]

The setattro/getattro will still allow custom logic for handling old settings? (As is currently done for VolumePlot)?

Not sure what you mean. set/getattro is the python 3 way to do set/getattr. Same function bodies. Slightly different call signatures.

We allow pre/post fixing code to set/getattr to allow processing old atts during a 'transition' period while people adjust their scripts. Similar to 'ProcessOldVersions' method for the C-Atts when reading configs/session files.
The logic is specified in the .code file and GeneratePython ensures it gets written.
Here's the VolumePlot.code section as an example:
https://github.com/visit-dav/visit/blob/ed72b88894b6c0fccccb6696f22ccefd1eef1983/src/plots/Volume/VolumeAttributes.code#L628C1-L671C1

Just want to make sure that this logic will still work after your changes (probably need to adjust the function name).

[markcmiller86]

I think the answer is that whatever GeneratePython.h did for get/setattr, it now does for get/setattro. Only the emitted function names and call signatures have changed.