Module Topllib.DataFlowQuery

Data-Flow Query Format

This reads "data flow queries" written in a minimal language, and converts them to other analyses. The concrete syntax is JSON. The abstract syntax is as follows.

 QUERY     ::= { "matchers": MATCHERS, "questions" : QUESTIONS, "language": LANGUAGE }
 MATCHERS  ::= [ MATCHER0, MATCHER1, ... ]
 QUESTIONS ::= [ QUESTION0, QUESTION1, ... ]
 MATCHER   ::= { "tag": TAG, "pattern": PATTERN, "arity": ARITY, "position": POSITION }
 QUESTION  ::= { "source": TAG, "sink": TAG }
 POSITION  ::= [ "ret" ]
 POSITION  ::= [ "arg", INDEX ]

where TAG is a string, PATTERN is a regex matching procnames, ARITY is a nonnegative integer, and INDEX is a 0-based index. A MATCHER has an optional field:

 MATCHER   ::= {  ..., "condition": [PREDICATE0, PREDICATE1, ...] }
 PREDICATE ::= [ "equal", VALUE, VALUE]
 VALUE     ::= POSITION
 VALUE     ::= CONSTANT

The content of CONSTANT varies by LANGUAGE. For example, if LANGUAGE is "erlang", then

 CONSTANT  ::= [ "atom", STRING ]
 CONSTANT  ::= [ "string", STRING ]
 CONSTANT  ::= [ "int", INTEGER ]

As a convenience, one can also specify a MATCHER as a JSON list rather than as a JSON object, in which case the list elements are, in order, TAG, PATTERN, ARITY, POSITION, CONDITION.