A CIL Tutorial - Department of Computer Science - ETH Zürich

CHAPTER 4. INSTRUMENTATION 37
type functions = {
mutable begin loop : varinfo;
mutable end loop : varinfo;
}
A dummy varinfo that we can use to initialize the functions record
let dummyVar = makeVarinfo false " tut foo" voidType
tutfuns is an instance of the record type functions that lets us quickly refer to the varinfos for
our instrumentation functions.
let tutfuns = {
begin loop = dummyVar;
end loop = dummyVar;
}
We set up some variables for the names of the instrumentation functions so that we only have one
string to change if the name of the functions changes in the C code.
let begin loop str = "tut begin loop"
let end loop str = "tut end loop"
We may wish subsequent passes over the code to ignore calls to instrumentation that we have added.
To make that easier, we dene a list of the function names, tut function names, and a function
isTutFun that tells if a function is an instrumentation call.
let tut function names = [
begin loop str;
end loop str;
]
let isTutFun (name : string) : bool =
L.mem name tut function names
The function mkFunTyp is a helper function for making simple function types. It can be used when
arguments and the function type itself have no attributes.
let mkFunTyp (rt : typ) (args : (string × typ) list) : typ =
TFun(rt, Some(L.map (fun a → (fst a, snd a, [ ])) args), false, [ ])
The function initTutFunctions initializes the tutfuns record.
function:
It does this by calling the Cil