A computer-implemented method for transforming implicit data structures expressed by assembler code into high-level language structures includes analyzing a section of assembler code to identify a plurality of data items. The computer-implemented method further includes storing the plurality of data items in a plurality of groups. The computer-implemented method further includes modifying one or more groups in the plurality of groups based, at least in part, on a pair of adjacent groups having a non-identical overlap. The computer-implemented method further includes creating an overlap list for each group. The computer-implemented method further includes generating data modeling language for the section based, at least in part, on each overlap list. A corresponding computer system and computer program product are also disclosed.