antmicro/verilator
Dec 2025 – Jun 2026
3 Months active
Languages Used
C++PythonSystemVerilogVerilog
Technical Skills
C++ developmentPython scriptingSystemVerilogTesting and validationVerilog designmemory management
Matthew Ballance
PROFILE
Matthew Ballance
Contributed to the antmicro/verilator repository by developing first-class SystemVerilog functional coverage, enabling users to define covergroups, coverpoints, and bins with runtime data collection and reporting. Addressed cross-language stability by refining DPI interactions between C++ and SystemVerilog, adding regression tests and safeguards for inheritance edge cases. Improved memory safety in ConstVisitor through scoped variable deletion, preventing use-after-free errors and enhancing simulation stability. The work emphasized test-driven development, precise commit practices, and expanded regression coverage, supporting maintainability and onboarding. Demonstrated expertise in C++, SystemVerilog, and software testing, delivering features and fixes that improved verification workflows and reliability within Verilator.
Overall Statistics
Feature vs Bugs
25%Features
Repository Contributions
5Total
Bugs
3
Commits
5
Features
1
Lines of code
9,728
Activity Months3
Your Network
96 peopleShared Repositories
96
Zhou ShenMember
Artur BieniekMember
Artur BieniekMember
github actionMember
Aleksander KirykMember
Adam KostrzewskiMember
jalcimMember
Thomas AldrianMember
Aliaksei ChapyzhenkaMember
Work History
June 2026
2 Commits • 1 Features
Jun 1, 2026June 2026 monthly summary for antmicro/verilator. Focused on delivering first-class SystemVerilog functional coverage and runtime coverage collection within Verilator, enabling users to define covergroups, coverpoints, and bins, and to collect and report coverage data during simulation. Implemented a runtime covergroup model (Phase A1) to support dynamic coverage collection. Added new classes and methods for coverage data generation and reporting, expanding verification capabilities and visibility. Commits driving the work: 2886291eba1e0e67f6ade4045d680ed97d1bfa59 and e03fa6c7839ca604fba57942d48363a26eeb7f00. Overall impact: enhances verification quality and efficiency by providing built-in coverage metrics, reducing reliance on external tooling and speeding feedback to developers. Technologies/skills demonstrated: C++, SystemVerilog integration, coverage data structures, runtime modeling, and verification workflow improvements within the Verilator project.
2 Commits • 1 Features
Jun 1, 2026June 2026 monthly summary for antmicro/verilator. Focused on delivering first-class SystemVerilog functional coverage and runtime coverage collection within Verilator, enabling users to define covergroups, coverpoints, and bins, and to collect and report coverage data during simulation. Implemented a runtime covergroup model (Phase A1) to support dynamic coverage collection. Added new classes and methods for coverage data generation and reporting, expanding verification capabilities and visibility. Commits driving the work: 2886291eba1e0e67f6ade4045d680ed97d1bfa59 and e03fa6c7839ca604fba57942d48363a26eeb7f00. Overall impact: enhances verification quality and efficiency by providing built-in coverage metrics, reducing reliance on external tooling and speeding feedback to developers. Technologies/skills demonstrated: C++, SystemVerilog integration, coverage data structures, runtime modeling, and verification workflow improvements within the Verilator project.
June 2026
January 2026
1 Commits
Jan 1, 2026January 2026 monthly summary for antmicro/verilator focused on memory-safety hardening in ConstVisitor to prevent use-after-free. Implemented a scoped variable deletion mechanism and updated invocation logic to ensure proper lifecycle management of variables under defined conditions. This work was committed as 8c977133c64075205e9cffb831d0831063478a2d (Fix use-after-free error #6846).
January 2026
1 Commits
Jan 1, 2026January 2026 monthly summary for antmicro/verilator focused on memory-safety hardening in ConstVisitor to prevent use-after-free. Implemented a scoped variable deletion mechanism and updated invocation logic to ensure proper lifecycle management of variables under defined conditions. This work was committed as 8c977133c64075205e9cffb831d0831063478a2d (Fix use-after-free error #6846).
December 2025
2 Commits
Dec 1, 2025Month: 2025-12 Key features delivered: - DPI Cross-Class Calling Stability Fix: resolved an internal fault in DPI cross-class calling by adjusting variable scope and lambda handling; added regression tests validating DPI interaction between C++ and SystemVerilog. - Guard against super.new() call without base class: added a guard to prevent runtime crashes when super.new() is invoked without a base class; included tests to verify correct error reporting. Major bugs fixed: - DPI cross-language boundary stability issues at the DPI boundary, reducing sporadic cross-language faults. - Inheritance edge-case crash when super.new() is called without a base class, now handled safely with clear error messaging. Overall impact and accomplishments: - Significantly improved reliability of DPI integrations and inheritance semantics in Verilator, reducing runtime crashes and increasing user trust. - Expanded regression test coverage for cross-language interactions and edge cases, enabling quicker detection of regressions. - Clearer commit messages and targeted tests, supporting maintainability and onboarding for contributors. Technologies/skills demonstrated: - C++, SystemVerilog, DPI, and cross-language debugging - Test-driven development and regression testing - Issue isolation, root-cause analysis, and safe code fixes - Git-based collaboration with precise commits (e.g., 3fc70b61d08b744b48e38ca7879024436fc8efd4; 0e03ab2a57f8f40d30a49117d0d452f62a6f1e57)
2 Commits
Dec 1, 2025Month: 2025-12 Key features delivered: - DPI Cross-Class Calling Stability Fix: resolved an internal fault in DPI cross-class calling by adjusting variable scope and lambda handling; added regression tests validating DPI interaction between C++ and SystemVerilog. - Guard against super.new() call without base class: added a guard to prevent runtime crashes when super.new() is invoked without a base class; included tests to verify correct error reporting. Major bugs fixed: - DPI cross-language boundary stability issues at the DPI boundary, reducing sporadic cross-language faults. - Inheritance edge-case crash when super.new() is called without a base class, now handled safely with clear error messaging. Overall impact and accomplishments: - Significantly improved reliability of DPI integrations and inheritance semantics in Verilator, reducing runtime crashes and increasing user trust. - Expanded regression test coverage for cross-language interactions and edge cases, enabling quicker detection of regressions. - Clearer commit messages and targeted tests, supporting maintainability and onboarding for contributors. Technologies/skills demonstrated: - C++, SystemVerilog, DPI, and cross-language debugging - Test-driven development and regression testing - Issue isolation, root-cause analysis, and safe code fixes - Git-based collaboration with precise commits (e.g., 3fc70b61d08b744b48e38ca7879024436fc8efd4; 0e03ab2a57f8f40d30a49117d0d452f62a6f1e57)
December 2025
Activity
Loading activity data...
Quality Metrics
Correctness96.0%
Maintainability80.0%
Architecture88.0%
Performance80.0%
AI Usage24.0%
Skills & Technologies
Programming Languages
C++PythonSystemVerilogVerilog
Technical Skills
C++C++ developmentPython scriptingSoftware DevelopmentSystemVerilogTesting and validationVerificationVerilog designfunctional verificationmemory managementsoftware testing
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline