1. A method, comprising: determining which target functions in a target binary have target function basic blocks that match source function basic blocks in a source function in a source binary by performing a hash-based matching between the target function basic blocks and the source function basic blocks, and performing a control flow-based matching on basic blocks that are unmatched after the hash-based matching, the control flow-based matching being performed within the unmatched basic blocks; and for the target functions having matching target function basic blocks, determining a corresponding target function control flow graph that has a greatest control flow matching strength to a source function control flow graph, wherein a node in the source function control flow graph represents a source function basic block, wherein a node in a target function control flow graph represents a target function basic block.