Total Internal Reflection

Technology and Art



Code

Cobol REKT
Tape/Z
Plenoxels
Transformer
Basis-Processing
Cataract
COMRADE
Duck-Angular
Exo
IRIS
MuchHeap
Snail-MapReduce
Underline
Lambda-Queuer
jQuery-Jenkins Radiator

Contact

Github
Twitter
LinkedIn

Site Feed

Tape/Z: An Overview

Avishek Sen Gupta on 22 June 2025

Abstract

We introduce Tape/Z, an evolving toolkit for analysing mainframe HLASM (High Level Assembler) code. The library provides capabilities for working with mainframe assembler code, including parsing, control flow graph building, dependency tracing, and flowchart visualization capabilities.

This post has not been written or edited by AI.

Writing the HLASM grammar

See Building an HLASM grammar from scratch for more details.

HLASM and SQL: Multi-pass parsing

Broadly, this extracts structure using multiple passes over the code. The purposes of these passes are detailed below:

The results are represented in a single JSON structure which contains HLASM, SQL, and macros, and is suitable for consumption into a graph for further analysis.

Multipass 1 Multipass 2

Control Flow Graph

CFG

References


tags: Software Engineering - Reverse Engineering - HLASM