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# Copyright (c) 2021-2026, Science and Technology Facilities Council.
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# -----------------------------------------------------------------------------
# Author: J. Henrichs, Bureau of Meteorology
# Modified: N. Nobre and S. Siso, STFC Daresbury Lab
'''PSyIR visitor layer that provides convenient functions that can be reused
for different language-specific visitors.
'''
import abc
from psyclone.psyir.backend.visitor import PSyIRVisitor, VisitorError
from psyclone.psyir.nodes import Member
[docs]
class LanguageWriter(PSyIRVisitor):
'''A convenience PSyIR visitor intermediate class. It provides
configuration options and functions that can be shared between different
language-specific visitors.
:param array_parenthesis: a tuple of two strings that contain the \
opening and closing parenthesis used for array accesses - e.g.:
("(", ")").
:type array_parenthesis: 2-tuple of str
:param str structure_symbol: the symbol to be used to address a
member of a structure, e.g. "%".
:param kwargs: additional keyword arguments provided to the super class.
:type kwargs: unwrapped dict.
:raises TypeError: if any of the supplied parameters are of the wrong type.
'''
# pylint: disable=too-many-arguments
def __init__(self, array_parenthesis, structure_character, **kwargs):
super().__init__(**kwargs)
if not isinstance(array_parenthesis, tuple) or \
len(array_parenthesis) != 2:
raise TypeError(f"Invalid array-parenthesis parameter, must be "
f"a tuple of two strings, got "
f"'{array_parenthesis}'.")
if not isinstance(structure_character, str):
raise TypeError(f"Invalid structure_character parameter, must be "
f"a string, got '{array_parenthesis}'.")
self._array_parenthesis = array_parenthesis
self._structure_character = structure_character
# ------------------------------------------------------------------------
@property
def array_parenthesis(self):
''':returns: the array parenthesis to be used in this language.
:rtype: two element list of str
'''
return self._array_parenthesis
# ------------------------------------------------------------------------
@property
def structure_character(self):
''':returns: the character use to access a member of a structure in \
this language.
:rtype: str
'''
return self._structure_character
# ------------------------------------------------------------------------
[docs]
@abc.abstractmethod
def gen_indices(self, indices, var_name=None):
'''Given a list of PSyIR nodes representing the dimensions of an
array, return a list of strings representing those array dimensions.
:param indices: list of PSyIR nodes.
:type indices: list of :py:class:`psyclone.psyir.symbols.Node`
:param str var_name: name of the variable for which the dimensions \
are created. Only used in the C implementation.
:returns: the code representation of the dimensions.
:rtype: list of str
'''
# ------------------------------------------------------------------------
[docs]
def arrayreference_node(self, node):
'''This method is called when an ArrayReference instance is found
in the PSyIR tree.
:param node: an ArrayNode PSyIR node.
:type node: :py:class:`psyclone.psyir.nodes.ArrayNode`
:returns: the code as a string.
:rtype: str
:raises VisitorError: if the node does not have any children.
'''
if not node.children:
raise VisitorError(
f"Incomplete ArrayReference node (for symbol '{node.name}') "
f"found: must have one or more children.")
args = self.gen_indices(node.children, node.name)
result = f"{node.name}{self._array_parenthesis[0]}"\
f"{','.join(args)}{self._array_parenthesis[1]}"
return result
# ------------------------------------------------------------------------
[docs]
def structurereference_node(self, node):
'''
Creates the code for an access to a member of a structure type.
:param node: a StructureReference PSyIR node.
:type node: :py:class:`psyclone.psyir.nodes.StructureReference`
:returns: the code as string.
:rtype: str
:raises VisitorError: if this node does not have an instance of Member\
as its only child.
'''
if len(node.children) != 1:
raise VisitorError(
f"A StructureReference must have a single child but the "
f"reference to symbol '{node.name}' has {len(node.children)}.")
if not isinstance(node.children[0], Member):
raise VisitorError(
f"A StructureReference must have a single child which is a "
f"sub-class of Member but the reference to symbol "
f"'{node.name}' has a child of type "
f"'{type(node.children[0]).__name__}'")
result = node.symbol.name + self._structure_character + \
self._visit(node.children[0])
return result
# ------------------------------------------------------------------------
[docs]
def member_node(self, node):
'''
Creates the code for an access to a member of a derived type.
:param node: a Member PSyIR node.
:type node: :py:class:`psyclone.psyir.nodes.Member`
:returns: the code as string
:rtype: str
'''
result = node.name
if not node.children:
# A simple member access that does not access any further
# structures, so just return the name itself
return result
if isinstance(node.children[0], Member):
# If the first child is a member, we are accessing a structure:
if len(node.children) > 1:
# If the node has more children, any additional children are
# array indices. Add the indices to the output string:
indices = self.gen_indices(node.children[1:], node.name)
result += f"{self._array_parenthesis[0]}{','.join(indices)}"\
f"{self._array_parenthesis[1]}"
# Now add the first child, which is the member that is being
# accessed, to the output string
result += self._structure_character + self._visit(node.children[0])
else:
# There is no access of a structure element, add the children
# (which exist since this was tested above) as indices to the
# output string.
args = self.gen_indices(node.children, node.name)
result += f"{self._array_parenthesis[0]}{','.join(args)}"\
f"{self._array_parenthesis[1]}"
return result
# ------------------------------------------------------------------------
[docs]
def arrayofstructuresreference_node(self, node):
'''
Creates the code for a reference to one or more elements of an
array of derived types.
:param node: an ArrayOfStructuresReference PSyIR node.
:type node: :py:class:`psyclone.psyir.nodes.ArrayOfStructuresReference`
:returns: the code as string.
:rtype: str
:raises VisitorError: if the supplied node does not have the correct \
number and type of children.
'''
if len(node.children) < 2:
raise VisitorError(
f"An ArrayOfStructuresReference must have at least two "
f"children but found {len(node.children)}")
if not isinstance(node.children[0], Member):
raise VisitorError(
f"An ArrayOfStructuresReference must have a Member as its "
f"first child but found '{type(node.children[0]).__name__}'")
# Generate the array reference. We need to skip over the first child
# (as that refers to the member of the derived type being accessed).
args = self.gen_indices(node.children[1:])
result = (node.symbol.name + self._array_parenthesis[0] +
",".join(args) + self._array_parenthesis[1] +
self._structure_character + self._visit(node.children[0]))
return result
# ------------------------------------------------------------------------
[docs]
def clause_node(self, node):
'''This method is called when a Clause instance is found in the
PSyIR tree. It returns the clause and its children as a string.
:param node: a Clause PSyIR node.
:type node: :py:class:`psyclone.psyir.nodes.Clause`
:returns: the code for this node.
:rtype: str
'''
result = node.clause_string
if len(node.children) > 0:
result = result + "("
child_list = []
for child in node.children:
child_list.append(self._visit(child))
result = result + ",".join(child_list)
result = result + ")"
return result
# For AutoAPI documentation generation
__all__ = ['LanguageWriter']
