loki.ir.find

Visitor classes that allow searching the IR

Functions

is_child_of(node, other)	Utility function to test relationship between nodes.
is_parent_of(node, other)	Utility function to test relationship between nodes.

Classes

FindNodes(match[, mode, greedy])	Find Node instances that match a given criterion.
FindScopes(match[, greedy])	Find all parent nodes for node match.
PatternFinder(pattern)	Find a pattern of nodes given as tuple/list of types within a given tree.
SequenceFinder(node_type)	Find repeated nodes of the same type in lists/tuples within a given tree.

class FindNodes(match, mode='type', greedy=False)

Bases: Visitor

Find Node instances that match a given criterion.

Parameters:

• match – Node type(s) or node instance to look for.

• mode (optional) –

  Drive the search. Accepted values are:

  • 'type' (default) : Collect all instances of type match.

  • 'scope' : Return the InternalNode in which the object match appears.

• greedy (bool, optional) – Do not recurse for children of a matched node.

Returns:

All nodes in the traversed IR that match the criteria.

Return type:

list

classmethod default_retval()

Default return value is an empty list.

Return type:

list

rules = {'scope': <function FindNodes.<lambda>>, 'type': <function FindNodes.<lambda>>}

Mapping of available mode selectors to match rules.

visit_object(o, **kwargs)

Fallback method for objects that do not match any handler.

Parameters:

• o – The object to visit.

• **kwargs – Optional keyword arguments passed to the visit methods.

Returns:

The default return value.

Return type:

GenericVisitor.default_retval()

visit_tuple(o, **kwargs)

Visit all elements in the iterable and return the combined result.

visit_list(o, **kwargs)

Visit all elements in the iterable and return the combined result.

visit_Node(o, **kwargs)

Add the node to the returned list if it matches the criteria and visit all children.

visit_TypeDef(o, **kwargs)

Custom handler for TypeDef nodes that does not traverse the body (reason being that discovering nodes such as declarations from inside the type definition would be unexpected if called on a containing Subroutine or Module)

class SequenceFinder(node_type)

Bases: Visitor

Find repeated nodes of the same type in lists/tuples within a given tree.

Parameters:

node_type – The node type to look for.

classmethod default_retval()

Default return value is an empty list.

Return type:

list

visit_tuple(o, **kwargs)

Visit all children and look for sequences of matching type.

visit_list(o, **kwargs)

Visit all children and look for sequences of matching type.

class PatternFinder(pattern)

Bases: Visitor

Find a pattern of nodes given as tuple/list of types within a given tree.

Parameters:

pattern (iterable of types) – The type pattern to look for.

classmethod default_retval()

Default return value is an empty list.

Return type:

list

static match_indices(pattern, sequence)

Return indices of matched patterns in sequence.

visit_tuple(o, **kwargs)

Visit all children and look for sequences of nodes with types matching the pattern.

visit_list(o, **kwargs)

Visit all children and look for sequences of nodes with types matching the pattern.

is_parent_of(node, other)

Utility function to test relationship between nodes.

Note that this can be expensive for large subtrees.

Returns:

Return True if other is contained in the IR below node, otherwise return False.

Return type:

bool

is_child_of(node, other)

Utility function to test relationship between nodes.

Note that this can be expensive for large subtrees.

Returns:

Return True if node is contained in the IR below other, otherwise return False.

Return type:

bool

class FindScopes(match, greedy=True)

Bases: FindNodes

Find all parent nodes for node match.

Parameters:

• match (Node) – The node for which the parent nodes are to be found.

• greedy (bool, optional) – Stop traversal when match was found.

visit_Node(o, **kwargs)

Add the node to the list of ancestors that is passed down to the children and, if o is match, return the list of ancestors.