Debugging Memory Leaks: A Field Guide to Valgrind and AddressSanitizer for C C++

Your process grows until something kills it. You ran the leak detector. Now you have forty records, and no idea which one is the bug.Every guide to Valgrind and AddressSanitizer teaches you to read the report. None of them teaches the part that actually takes the afternoon: getting from a report entry to the line that is wrong.That distance exists for a structural reason. A leak detector can only observe allocation, so it tells you where memory was born. The defect is at the ownership decision - whoever was supposed to release it and didn't - which is a different file, often a different author. This book is a procedure for crossing that gap.What you get: A three-measurement test that tells you in twenty minutes whether you have a leak at all, before you install anything. Four things routinely mistaken for leaks, and how to rule each one out.One rule for choosing between Valgrind and the sanitizers, based on your build system rather than your preference - plus the cost figure almost nobody knows, which changes the decision entirely.A ranking rule that finds your bug on the first record instead of the largest one.A six-step traversal from allocation site to ownership defect, with the four break shapes that account for nearly all of them.The chapter no documentation contains: what to do when the report comes back empty and memory still climbs. Still-reachable growth, caches with no eviction, reference cycles - the leaks that no tool reports because nothing was ever lost.How to write a suppression that silences one thing instead of silencing next year's bug, and how to audit the file you inherited.How to make a leak fail the build, including the ratchet that stops the check being switched off in week two.What this is not. Not a tool reference - the official Valgrind and LLVM documentation is free, authoritative, and better at that job. Not a memory-management tutorial. Not a tour of the Valgrind suite. It covers one defect, narrowly, and tells you early if yours is a different one.Short on purpose. Your process is dying today.