
Jeroen Ketema contributed to the CodeQL and codeql-coding-standards repositories by building and evolving static analysis tooling for C++, Swift, and Go. He engineered schema migrations, upgrade/downgrade scripts, and cross-language test infrastructure to support reliable database evolution and language compatibility. His work included expanding C++ support for variable-length arrays, precompiled headers, and ARM architectures, while also enhancing Swift backend features and Go toolchain integration. Using C++, QL, and Python, Jeroen focused on robust test automation, code quality, and documentation, addressing complex extraction, dataflow, and integration challenges to improve analysis accuracy, maintainability, and release workflows across multiple platforms.

October 2025: Delivered a critical bug fix and code-quality improvements for the Swift tracer integration in CodeQL. The work focused on correctly resolving the Swift resource directory when -Xcc is used, improving tracer reliability across clang-based builds, and refactoring resource-dir handling to accommodate complex compiler argument orders. This enhances patching accuracy and overall CI reliability.
October 2025: Delivered a critical bug fix and code-quality improvements for the Swift tracer integration in CodeQL. The work focused on correctly resolving the Swift resource directory when -Xcc is used, improving tracer reliability across clang-based builds, and refactoring resource-dir handling to accommodate complex compiler argument orders. This enhances patching accuracy and overall CI reliability.
September 2025 monthly summary for github/codeql: Delivered cross-language enhancements with a focus on C++ VLA handling, Swift and Go tooling upgrades, and test/documentation improvements. Implemented and extended features and fixes that improve analysis accuracy, test coverage, and release readiness across languages. Key features include C++ sizeof VLAs support with extensive tests (including ArrayExprs, typedefs, base-type extraction, IR conversions) and documentation for TranslatedSizeofExpr and VlaDeclStmt; Swift upgrade to 6.1.3 with LFS adjustments; and Go/Swift change-log and playbook updates to reflect new norms. Major bug fixes encompassed: updating tests after extractor changes; fixing base-type extraction for VLAs; adding necessary conversions in VLA IR; plus broad test result updates. Overall impact: higher reliability of static analysis for VLAs, improved developer workflow, and better alignment with language/tooling ecosystems. Technologies/skills demonstrated: C++, IR, VLAs, typedefs, ArrayExpr handling, test automation, documentation, Swift 6.1.3/LFS, change management, and cross-language release hygiene.
September 2025 monthly summary for github/codeql: Delivered cross-language enhancements with a focus on C++ VLA handling, Swift and Go tooling upgrades, and test/documentation improvements. Implemented and extended features and fixes that improve analysis accuracy, test coverage, and release readiness across languages. Key features include C++ sizeof VLAs support with extensive tests (including ArrayExprs, typedefs, base-type extraction, IR conversions) and documentation for TranslatedSizeofExpr and VlaDeclStmt; Swift upgrade to 6.1.3 with LFS adjustments; and Go/Swift change-log and playbook updates to reflect new norms. Major bug fixes encompassed: updating tests after extractor changes; fixing base-type extraction for VLAs; adding necessary conversions in VLA IR; plus broad test result updates. Overall impact: higher reliability of static analysis for VLAs, improved developer workflow, and better alignment with language/tooling ecosystems. Technologies/skills demonstrated: C++, IR, VLAs, typedefs, ArrayExpr handling, test automation, documentation, Swift 6.1.3/LFS, change management, and cross-language release hygiene.
August 2025 monthly summary for the CodeQL repository. Focused on upgrading the Go toolchain to 1.25, expanding C++ capabilities (PCH support and related tooling), and stabilizing the test and integration suites after extractor changes. Delivered new build/test infrastructure enhancements while improving test coverage and documentation.
August 2025 monthly summary for the CodeQL repository. Focused on upgrading the Go toolchain to 1.25, expanding C++ capabilities (PCH support and related tooling), and stabilizing the test and integration suites after extractor changes. Delivered new build/test infrastructure enhancements while improving test coverage and documentation.
July 2025 performance summary: Delivered critical schema evolution capabilities, improved code organization, expanded test coverage, and enhanced dataflow/introspection features across CodeQL repositories. Focused on migration reliability, maintainability of the dbscheme, and exposing richer dataflow/Typeid constructs for QL analysis, with extensive testing and documentation updates to support deployment and long-term maintainability.
July 2025 performance summary: Delivered critical schema evolution capabilities, improved code organization, expanded test coverage, and enhanced dataflow/introspection features across CodeQL repositories. Focused on migration reliability, maintainability of the dbscheme, and exposing richer dataflow/Typeid constructs for QL analysis, with extensive testing and documentation updates to support deployment and long-term maintainability.
June 2025 CodeQL monthly summary for repo github/codeql. Focused on stability, cross-architecture portability, and maintainability with effective tooling and testing improvements that deliver measurable business value. Key feature work tightened migration workflows and expanded architecture support, while metrics and quality processes were upgraded to improve reliability and transparency.
June 2025 CodeQL monthly summary for repo github/codeql. Focused on stability, cross-architecture portability, and maintainability with effective tooling and testing improvements that deliver measurable business value. Key feature work tightened migration workflows and expanded architecture support, while metrics and quality processes were upgraded to improve reliability and transparency.
May 2025 monthly summary for github/codeql: Swift backend enhancements expanded language coverage, C++ robustness improvements, Windows dataflow modeling, and ongoing release hygiene. The month delivered targeted Swift backend features, stabilization fixes, tooling upgrades for Swift 6.1 readiness, Cross-language test coverage, and build/config cleanups that reduce release risk. Business value includes faster onboarding to newer Swift versions, safer tool upgrades, broader analysis coverage, and cleaner release workflows.
May 2025 monthly summary for github/codeql: Swift backend enhancements expanded language coverage, C++ robustness improvements, Windows dataflow modeling, and ongoing release hygiene. The month delivered targeted Swift backend features, stabilization fixes, tooling upgrades for Swift 6.1 readiness, Cross-language test coverage, and build/config cleanups that reduce release risk. Business value includes faster onboarding to newer Swift versions, safer tool upgrades, broader analysis coverage, and cleaner release workflows.
April 2025 monthly summary for github/codeql: Delivered key features across C++ and Swift, stabilized testing, and improved safety in dataflow analysis. Major feature work includes C23 typeof support, upgrade/downgrade scripting, and configurable Field Flow limits, complemented by Swift mangling updates and stricter test verifications. These changes advance language compatibility, tooling robustness, and platform coverage, delivering business value and reducing defect surfaces.
April 2025 monthly summary for github/codeql: Delivered key features across C++ and Swift, stabilized testing, and improved safety in dataflow analysis. Major feature work includes C23 typeof support, upgrade/downgrade scripting, and configurable Field Flow limits, complemented by Swift mangling updates and stricter test verifications. These changes advance language compatibility, tooling robustness, and platform coverage, delivering business value and reducing defect surfaces.
For 2025-03, CodeQL C++ analysis work focused on frontend-driven alignment of tests and docs, bug fixes in diagnostics escaping, and metadata/documentation updates to reflect frontend changes. These efforts improve diagnostic accuracy, reliability of test expectations after frontend updates, and clarity for compiler support, contributing to faster CI feedback and more predictable developer experiences.
For 2025-03, CodeQL C++ analysis work focused on frontend-driven alignment of tests and docs, bug fixes in diagnostics escaping, and metadata/documentation updates to reflect frontend changes. These efforts improve diagnostic accuracy, reliability of test expectations after frontend updates, and clarity for compiler support, contributing to faster CI feedback and more predictable developer experiences.
February 2025 monthly summary for github/codeql focusing on the C++ extractor test alignment improvements. The month concentrated on ensuring the extractor’s handling of unnamed code blocks is consistently reflected in tests, stabilizing test results, and tightening the feedback loop around changes to the C++ extraction pipeline.
February 2025 monthly summary for github/codeql focusing on the C++ extractor test alignment improvements. The month concentrated on ensuring the extractor’s handling of unnamed code blocks is consistently reflected in tests, stabilizing test results, and tightening the feedback loop around changes to the C++ extraction pipeline.
January 2025 performance-focused CodeQL project update highlighting targeted feature delivery, stability improvements, and data-quality enhancements across two repositories. Key outcomes include performance optimization in C++ analysis, extended support for mixed typedef/using declarations, and automated C++ language upgrade/downgrade tooling, accompanied by refined metrics and test expectations. A precision enhancement for QL Rule A2-10-4 was implemented to reduce false positives for static non-member objects within namespaces, improving result accuracy for downstream users.
January 2025 performance-focused CodeQL project update highlighting targeted feature delivery, stability improvements, and data-quality enhancements across two repositories. Key outcomes include performance optimization in C++ analysis, extended support for mixed typedef/using declarations, and automated C++ language upgrade/downgrade tooling, accompanied by refined metrics and test expectations. A precision enhancement for QL Rule A2-10-4 was implemented to reduce false positives for static non-member objects within namespaces, improving result accuracy for downstream users.
December 2024 monthly summary for github/codeql-coding-standards: Focused on Code Analysis Rules and Test Suite Maintenance. Delivered maintenance updates to in-code analysis rules and tests to reflect macro identifier distinctness and identifier hiding, and migrated CodeQL queries from deprecated TemplateParameter to TypeTemplateParameter to preserve accuracy and compatibility. These changes ensure reliable static analysis results, reduce false positives, and improve long-term maintainability in response to CodeQL deprecations. Commits include 40d7800f77d588e67b394a1604682cb7320e1236 (Update expected test results) and 065dc013edd676c420fa86f9fe6cebb9a7ae9394 (Update queries after TemplateParameter deprecation).
December 2024 monthly summary for github/codeql-coding-standards: Focused on Code Analysis Rules and Test Suite Maintenance. Delivered maintenance updates to in-code analysis rules and tests to reflect macro identifier distinctness and identifier hiding, and migrated CodeQL queries from deprecated TemplateParameter to TypeTemplateParameter to preserve accuracy and compatibility. These changes ensure reliable static analysis results, reduce false positives, and improve long-term maintainability in response to CodeQL deprecations. Commits include 40d7800f77d588e67b394a1604682cb7320e1236 (Update expected test results) and 065dc013edd676c420fa86f9fe6cebb9a7ae9394 (Update queries after TemplateParameter deprecation).
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