Infeasible Path Detection Based on Code Pattern and Backward Symbolic Execution

Algorithm 1

Search feasible path for n BACKWARDSEARCH.

	Require: Target n, CFG  = {N, E, ne, no}
	Ensure: A feasible path from ne to n path;
	if first then
	SYMBOLICINIT (inputparams);
	path ⇐ INITPATH()
	state ⇐ initState;
	end if
	if n is in then
	Return Pathin;
	end if
	for each pre in precessors of n do
	STORESTATE();
	b_flag⇐ EDGEOF(pre, n);
	if pre is C then
	;
	end if
	if pre is A then
	[x: symbolExpression]⇐ SYMBOLICEXECUTION(pre);
	;
	;
	end if
	if IsCONSTRAINTSCONSISTENT is TRUE then
	BACKWARDSEARCH ;
	else
	RESTORE STATE();
	continue;
	end if
	end for