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Frank Schüssele

PROFILE

Frank Schüssele

Florian Schüßler contributed to the ultimate-pa/ultimate repository by engineering core verification and translation features that improved reliability, maintainability, and analysis accuracy. He developed and refactored components for C and Java, focusing on static analysis, witness validation, and backend reporting. His work included extending ACSL support, enhancing memory and array handling, and introducing robust result types for clearer analysis outcomes. Florian applied skills in Java, C, and build automation to streamline workflows, optimize performance, and reduce technical debt. His approach emphasized code quality, regression coverage, and extensible architecture, resulting in a stable foundation for ongoing formal verification development.

Overall Statistics

Feature vs Bugs

57%Features

Repository Contributions

399Total
Bugs
95
Commits
399
Features
127
Lines of code
256,980
Activity Months22

Work History

February 2026

3 Commits • 1 Features

Feb 1, 2026

February 2026: Implemented NotAnalyzedResult as a dedicated result type to clearly represent analyses that cannot complete, and updated the backend reporting pipeline (ResultUtil and UltimateResultConverter). Extended full support to WebBackend and ensured reports emit NotAnalyzedResult instead of UnprovableResult when analysis stops early. This improves clarity, robustness, and trust in downstream dashboards and decisions.

January 2026

1 Commits

Jan 1, 2026

January 2026, repository: ultimate-pa/ultimate. Focused on stabilizing library functionality and ensuring reliable runtime behavior. Key activity: fixed an incorrect JAXB import that restored library functionality and downstream runtime behavior. This fix prevents runtime errors in dependent components and enables ongoing feature work with a stable base.

December 2025

2 Commits • 1 Features

Dec 1, 2025

December 2025: Delivered stability and translation robustness for ultimate-pa/ultimate. Key outcomes include a critical testing configuration fix to restore reliable CI and a major data-structure enhancement to the C translation pipeline. These changes reduce build/test flakiness, improve correctness of CArray handling, and position the project for safer future expansions.

November 2025

57 Commits • 12 Features

Nov 1, 2025

In November 2025, the Ultimate project focused on strengthening SV-COMP integration, memory-model robustness, and validation infrastructure to deliver reliable pre-run analyses, reduce CI noise, and improve confidence in automated witnesses.

October 2025

5 Commits • 3 Features

Oct 1, 2025

October 2025 performance summary for ultimate-pa/ultimate: delivered robust floating-point math enhancements, hardened memory handling, and improved testing/verification workflows. The work focused on increasing correctness, stability, and developer productivity with clear business value.

September 2025

4 Commits • 2 Features

Sep 1, 2025

September 2025 monthly summary for ultimate-pa/ultimate focused on reliability, translation accuracy, and regression coverage. Delivered concrete improvements in test hygiene, variable declaration logic, and initialization regression testing, aligning technical work with business value of more reliable software and faster delivery.

July 2025

4 Commits

Jul 1, 2025

July 2025 monthly summary for ultimate-pa/ultimate focusing on reliability, performance, and developer experience. Delivered three targeted fixes/improvements that enhance runtime efficiency, cross-environment consistency, and readability: - Memory Handling Optimization and Bug Fix (Issue #731): removed an unnecessary loop in memmove/memcpy when heap pointers are not required, addressing the issue and boosting efficiency in hot memory paths. - IDE Formatter Configuration Cleanup and Update (Eclipse): removed non-functional formatter settings and updated configuration to align with Eclipse 2025, ensuring consistent code formatting across environments and backward compatible with 2024. - Pointer Dereference Validity Checks Description Formatting: improved UI/description readability for CC-related pointer dereference validity checks, enhancing developer understanding. Overall impact: improved runtime efficiency, more predictable formatting across developer environments, and clearer code-quality descriptions. These changes reduce maintenance burden and improve onboarding for new contributors. Technologies/skills demonstrated: low-level memory optimization in C, debugging and issue-driven fixes, Eclipse formatter configuration and version compatibility, UI/UX readability improvements, cross-environment consistency.

June 2025

3 Commits • 2 Features

Jun 1, 2025

June 2025 monthly summary for ultimate-pa/ultimate focusing on reliability, performance, and build hygiene. Delivered a critical bug fix removing unsupported pointer-integer cast modes, added build-time dependency management for the web interface, and improved WebBackend startup performance by tuning the Equinox resolver. These changes reduce runtime edge cases, improve deployment reliability, and shorten startup times for users, reinforcing platform stability and developer efficiency. All work aligns with business goals of stronger reliability and faster time-to-value for customers.

May 2025

14 Commits • 4 Features

May 1, 2025

May 2025 performance highlights for ultimate-pa/ultimate: Delivered core language-analysis enhancements and stabilized the build. Key features include binary literals support in C parsing and analysis, variadic argument macro support (va_arg) in the GCC static language settings provider, and configurable ACSL assertion checks with robustness to prevent unnecessary toolchain cancellations. Addressed critical bugs in CACSL2BoogieTranslator for correct loop invariant computation when continue statements are present, and removed an unused struebli dependency to resolve build failures. Ongoing internal maintenance and refactoring improved interface consistency and maintainability, preparing the codebase for future enhancements. These changes improve parsing accuracy, reduce false positives, increase reliability of analysis, and streamline development.

April 2025

25 Commits • 14 Features

Apr 1, 2025

April 2025 (2025-04) monthly summary for repository ultimate-pa/ultimate focusing on delivering features, stabilizing the codebase, and expanding test coverage.

March 2025

35 Commits • 7 Features

Mar 1, 2025

March 2025 highlights for ultimate-pa/ultimate focusing on code quality, API clarity, and maintainability. Delivered a foundational refactor, cleaned up build and dependencies, and fixed critical Sonar issues, resulting in more robust code and faster onboarding for new contributors.

February 2025

18 Commits • 3 Features

Feb 1, 2025

February 2025 focused on stabilizing the codebase, expanding ACSL support, and improving nightly-build reliability to reduce noise and improve long-term maintainability. Deliveries targeted business value through stronger static-analysis translation, more robust AST dispatch, and cleaner tooling for sustainable development.

January 2025

45 Commits • 12 Features

Jan 1, 2025

January 2025: Strengthened ACSL support, regression reliability, and internal refactors in ultimate-pa/ultimate. Delivered feature-rich ACSL handling with quantifiers and \\old/\\at support, aligned backtranslation and Kojak regression tests, and introduced dispatch and memory handling cleanups. Implemented switch-pattern matching for ACSLPrettyPrinter and MainDispatcher to simplify dispatch. Enhanced backtranslation behavior for \\at, updated error messaging, and improved test stability across witnesses and Referee. Completed maintenance work to improve code quality and future extensibility.

December 2024

18 Commits • 4 Features

Dec 1, 2024

December 2024 (2024-12) monthly summary for ultimate-pa/ultimate. Focused on robustness, reliability, and performance to deliver business value in verification workflows and build startup efficiency. Key features delivered: - XML Formatter Fallback Support: added XML as a backup formatter path for EPF imports to increase resilience when the primary import fails. Commits: fd0345344badd361adc1b9791fad45636a5c81aa - Product Initialization Performance Optimization: speed startup by configuring equinox.resolver.revision.batch.size=1 across product files. Commit: 900a6e90386a4a890f4214840a288d51ea52e813 - Internal Refactors, Maintenance, and Witness Handling Cleanup: consolidate maintenance, refactor assertion order, inline witness validation, and clean up YAML witness data. Commits include 3ddba7f91dc0ed78ad03190f42a92324067690c7, e294632bcbe6dba94744e059f1e13b21fa3c00ae, 1cfc6d2dbc0f5873312683b337b3c77b98ddab4a, 48d48ebd254026f74c3cc339b6c5f5c73e47042a, 05d00bc2e98c1141b7fc1ac06e4eeab1b7bea38d, 4941ac7fd3195131b395e29103639e3735431393, 0988ca815c09cad145778078c049433dae9a1665 Major bugs fixed: - ACSL and Loop Invariant Robustness: improve verification robustness by ensuring loop invariants are boolean, tighten ACSL boolean conversion, and add regression tests. Commits: 99dbfa7eeb6140870edb0e8c5a137902a2b9ab33, 11ef26524766b5c985f2676f79ada31b98ee59ec, 1c4755c57abfb0423100d1eb7e75d686da30339d - Test Infrastructure and Regression Test Reliability: reorganize tests to exclude MathSAT where unsupported, fix regression test folder casing, and add regression test for boolean bitwise operations. Commits: 228894eee338451d5147625cfb38df359da6dee4, f251819c2e1c56337d318a713f87d7d1d4a92c32, f208d9114a26a8642f526a28f25560412a83e75d - MathSAT Rounding Mode Error Handling: classify unknown symbol roundNearestTiesToAway as known-ignored. Commit: 6f249bbaa926bc36e74907f0f3e5b6f71097daf7 Overall impact and accomplishments: - Increased verification reliability, reduced test fragility, and faster startup; improved resilience of EPF imports and witness handling; reduced maintenance overhead through targeted refactors. Technologies/skills demonstrated: - Formal verification tooling (ACSL), regression testing, test infrastructure improvements, performance tuning, YAML witness data handling, and robust error classification for external solvers.

November 2024

144 Commits • 50 Features

Nov 1, 2024

November 2024 (2024-11) – The Ultimate project delivered a set of performance, reliability, and SV-COMP readiness improvements, with broad adoption of IcfgBuilder across settings/toolchains, and targeted bug fixes stabilizing the core analysis flow. Business value came from faster evaluations, more predictable results, and cleaner build/test workflows through dependency migrations and toolchain harmonization. Key outcomes include speeding up evaluation by excluding hardness tasks, updating MathSAT to 5.6.11, and fixing critical correctness issues such as bitvector settings and NaN/infinity backtranslation errors. The month also advanced code hygiene and testing, aligning with SV-COMP requirements and improved error messaging.

October 2024

6 Commits • 4 Features

Oct 1, 2024

October 2024 performance summary for ultimate-pa/ultimate focused on delivering a robust benchmarking and stability feature set, enabling structured evaluation of bitvector solvers and improving development workflows. The work emphasized reproducible benchmarking, resilient configuration management, and precision in parameter handling to support scalable future work.

September 2024

1 Commits

Sep 1, 2024

2024-09 monthly summary for ultimate-pa/ultimate focused on stability and maintainability improvements in the product automaton. Delivered a targeted bug fix by refactoring getSuccessorCounter to a for-loop, enhancing readability and preventing exceptions when the witness ends with an assumption. This change improves the robustness of segment counter handling within the product state. No new features shipped this month; the emphasis was on improving reliability and code quality to enable safer future development.

August 2024

3 Commits • 2 Features

Aug 1, 2024

Concise monthly summary for 2024-08 focused on delivering new capabilities and API improvements in the ultimate-pa/ultimate repository, with emphasis on business value, maintainability, and extensibility.

July 2024

4 Commits • 2 Features

Jul 1, 2024

July 2024 performance summary for ultimate-pa/ultimate. Focused two major feature deliveries and targeted bug fixes to stabilize the verification pipeline and improve diagnostic quality. Key features delivered: - Boogie/C translation accuracy and ICFG pipeline robustness: Improved translation of C control flow into Boogie and fixed ICFG backtranslator state handling to ensure correct translation and a stable, compatible pipeline. Related commits addressed: Fix translation for while statements w.r.t ConditionAnnotation; Fix for new ICFG in WitnessPrinter; Bugfix: Do not just reuse ateBuilder. - Enhanced YAML violation witness details: YAMLViolationWitnessGenerator now captures the column number of violations to improve YAML output diagnostics. Commit: Write column to violation witness. Major bugs fixed: - Corrected translation behavior for while statements with ConditionAnnotation to prevent mis-translation. - Stabilized ICFG integration with WitnessPrinter for the new ICFG workflow. - Eliminated reuse of stale ateBuilder to avoid state bleed and ensure fresh translations. - Added column-level diagnostics to violation witnesses for precise YAML reporting. Overall impact and accomplishments: - Increased pipeline stability and reliability of C-to-Boogie translation, reducing downstream verification failures. - Faster root-cause analysis through column-level diagnostics and improved ICFG/backtranslator consistency. - Demonstrated end-to-end capability across translation, ICFG pipeline, and diagnostic reporting, enabling more predictable releases. Technologies/skills demonstrated: - Boogie translation, C control-flow analysis, ICFG/backtranslator state management - WitnessPrinter integration and ICFG compatibility - YAML-based diagnostics, column-level error reporting - Debugging, performance-focused fixes, and cross-component collaboration Business value: - Reduced time to diagnose and fix verification issues, improved stability for ongoing CI workflows, and better diagnostic clarity for developers and QA.

June 2024

3 Commits • 1 Features

Jun 1, 2024

June 2024: Delivered key improvements to program state representation and witness generation for ultimate-pa/ultimate. Implemented a shared ProgramStatePrinter to convert program states to YAML and GraphML, enabling interoperable state representations and streamlined witness outputs. Refactored code to use the new printing functionality across formats, and enhanced witness data for debugging and analysis. Added line/column extraction in StepInfo and expanded violation witness with new function and columns, improving precision and observability. These changes reduce manual effort, speed up debugging, and improve downstream integration.

April 2024

1 Commits • 1 Features

Apr 1, 2024

April 2024 (ultimate-pa/ultimate): Implemented witness validation in YAML for violation witnesses and introduced IWitnessTransformer to enable automata transformation via witnesses. Refactor updated core classes to leverage the new interface, enhancing witness handling across BuchiAutomizer and TraceAbstraction. This work improves reliability of automated proofs, enables YAML-based workflows, and lays groundwork for future witness-driven features.

February 2024

3 Commits • 2 Features

Feb 1, 2024

February 2024 monthly summary for ultimate-pa/ultimate: delivered reliable SVG export improvements and updated code formatting standards, strengthening export reliability, reducing risk of overwrites, and enabling use of new Java features.

Activity

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Quality Metrics

Correctness88.8%
Maintainability89.4%
Architecture84.2%
Performance80.8%
AI Usage20.8%

Skills & Technologies

Programming Languages

ACSLBPLBashCC++ConfigurationCupEPFEclipse PreferencesEclipse Settings

Technical Skills

ACSLAST ManipulationAST ParsingAST manipulationAbstract Class ImplementationAbstract InterpretationAbstract Syntax Tree (AST) ManipulationAbstract Syntax Tree ManipulationAlgorithm DesignAnnotation ProcessingAssertionAssertion HandlingAutomata TheoryAutomated TestingAutomated Theorem Proving

Repositories Contributed To

1 repo

Overview of all repositories you've contributed to across your timeline

ultimate-pa/ultimate

Feb 2024 Feb 2026
22 Months active

Languages Used

JavaXMLPythonBPLCC++ConfigurationEPF

Technical Skills

Code FormattingError HandlingFile HandlingGUI DevelopmentJavaSoftware Development