python_graphs.data_flow.LastAccessAnalysis

class documentation

class LastAccessAnalysis(Analysis): (source)

Computes for each variable its possible last reads and last writes.

Method	`__init__`	Undocumented
Method	`aggregate_previous_after_values`	Computes the before value for a node from the previous after values.
Method	`compute_after_value`	Computes the after value for a node from the node and the before value.

Inherited from Analysis:

Method	`visit`	Visit the nodes of the control flow graph, performing the analysis.
Instance Variable	`after_label`	Either the in_label or out_label depending on the direction of the analysis. Marks the after_value on a node during an analysis.
Instance Variable	`before_label`	Either the in_label or out_label depending on the direction of the analysis. Marks the before_value on a node during an analysis.
Instance Variable	`forward`	(bool) True for forward analyses, False for backward analyses.
Instance Variable	`in_label`	The name of the analysis, suffixed with _in.
Instance Variable	`label`	The name of the analysis.
Instance Variable	`out_label`	The name of the analysis, suffixed with _out.

overrides python_graphs.data_flow.Analysis.__init__

Undocumented

def aggregate_previous_after_values(self, previous_after_values): (source) ¶

overrides python_graphs.data_flow.Analysis.aggregate_previous_after_values

Computes the before value for a node from the previous after values.

This is the 'meet' or 'join' function of the analysis. TODO(dbieber): Update terminology to match standard textbook notation.

Parameters
previous_after_values	The after values of all before nodes.
Returns
The before value for the current node.

def compute_after_value(self, node, before_value): (source) ¶

overrides python_graphs.data_flow.Analysis.compute_after_value

Computes the after value for a node from the node and the before value.

This is the 'transfer' function of the analysis. TODO(dbieber): Update terminology to match standard textbook notation.

Parameters
node	The node or block for which to compute the after value.
before_value	The before value of the node.
Returns
The computed after value for the node.