Adventures with C++ Legacy Codebases: Tales of Incremental Improvement
Talkat CppCon 2024 · on Wednesday, 2024-09-18· at 16:45· Cottonwood 8/9, 6700 North Gaylord Rockies Boulevard·
summary
Three merged 20+ year C++ codebases total millions of lines and the concrete wins are specific: incremental rollout of ASan and UBSan and unit/regression tests finds real UB, clang-format and clang-tidy diff enforce style and deprecations only on changed lines, a dynamic DLL boundary reliably shares DSP code, and a brittle but effective static-lib workaround ships analytics. Expect false positives from sanitizers, lint-driven refactors to introduce bugs, and that copy‑paste works for tiny pure functions but breaks on change.
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chapters (14)
- 0:00Introduction
- 1:03Legacy code challenges
- 3:28Common perceptions
- 7:42Modernizing risks
- 12:19Style guides with clang-format
- 15:29Static analysis and sanitizers
- 21:48Deprecating APIs
- 27:52clang-tidy for refactoring
- 32:29Sharing legacy code
- 36:0520-year-old code challenges
- 38:14DSP library sharing
- 41:23Copy-paste strategies
- 43:11Static library sharing
- 46:29Summary
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