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.