Gdb

mohitmishra786/low-level-dev-skills/skills/debuggers/gdb

作者 mohitmishra786bdc58472fa9f无许可证253 个星标收录于 2026年10月9日更新于 2026年10月9日仓库3个月前更新

GDB debugger skill for C/C++ programs. Use when starting a GDB session, setting breakpoints, stepping through code, inspecting variables, debugging crashes, using reverse debugging (record/replay), remote debugging with gdbserver, or loading core dumps. Activates on queries about GDB commands, segfaults, hangs, watchpoints, conditional breakpoints, pretty-printers, Python GDB scripting, or multi-threaded debugging.

仅含说明Software Development
AI 生成的概览

指导代理使用 GDB 调试 C/C++ 程序，涵盖断点、崩溃诊断、反向调试与远程调试。

功能
该技能提供针对 C/C++ 程序的 GDB 会话结构化指引。内容包括带调试信息编译、启动 GDB、常用单步与状态查看命令、断点与观察点、多线程调试、基于 record/replay 的反向调试、通过 gdbserver 的远程调试，以及常见故障现象与修复方法。它还指向命令速查表以及 pretty-printer 与 Python 脚本编写的参考文档。
适用场景
当 C/C++ 程序崩溃、段错误、挂起或缺少符号，需要用 GDB 排查时使用。也适用于设置断点或观察点、查看变量、内存、寄存器或线程、确定性地重放缺陷、调试远程或嵌入式目标，以及加载核心转储。
运行要求
不附带脚本，只有说明文档和两份参考文档。使用所述流程需要安装 GDB、C/C++ 工具链（如 GCC 或 Clang）；远程调试还需要目标端的 gdbserver 以及主机与目标之间的网络访问。

GDB

Purpose

Walk agents through GDB sessions from first launch to advanced workflows: crash diagnosis, reverse debugging, remote debugging, and multi-thread inspection.

Triggers

  • "My program segfaults / crashes — how do I debug it?"
  • "How do I set a breakpoint on condition X?"
  • "How do I inspect memory / variables in GDB?"
  • "How do I debug a remote embedded target?"
  • "GDB shows ?? frames / no source"
  • "How do I replay a bug deterministically?" (record/replay)

Workflow

1. Prerequisite: compile with debug info

Always compile with -g (GCC/Clang). Use -Og or -O0 for most debuggable code.

bash
gcc -g -Og -o prog main.c

For release builds: use -g -O2 and keep the binary with symbols (strip separately with objcopy).

2. Start GDB

bash
gdb ./prog                          # load binarygdb ./prog core                     # load with core dumpgdb -p 12345                        # attach to running processgdb --args ./prog arg1 arg2         # pass argumentsgdb -batch -ex 'run' -ex 'bt' ./prog  # non-interactive (CI)

3. Essential commands

CommandShortcutEffect
run [args]rStart the program
continuecResume after break
nextnStep over (source line)
stepsStep into
nextiniStep over (instruction)
stepisiStep into (instruction)
finishRun to end of current function
until NRun to line N
return [val]Force return from function
quitqExit GDB

4. Breakpoints and watchpoints

gdb
break main                          # break at functionbreak file.c:42                     # break at linebreak *0x400abc                     # break at addressbreak foo if x > 10                 # conditional breaktbreak foo                          # temporary breakpoint (fires once)rbreak ^mylib_.*                    # regex breakpoint on all matching functions
watch x                             # watchpoint: break when x changeswatch *(int*)0x601060               # watch memory addressrwatch x                            # break when x is readawatch x                            # break on read or write
info breakpoints                    # list all breakpointsdelete 3                            # delete breakpoint 3disable 3                           # disable without deletingenable 3

5. Inspect state

gdb
print x                             # print variableprint/x x                           # print in hexprint *ptr                          # dereference pointerprint arr[0]@10                     # print 10 elements of arraydisplay x                           # auto-print x on every stopundisplay 1
info locals                         # all local variablesinfo args                           # function argumentsinfo registers                      # all CPU registersinfo registers rip rsp rbp          # specific registersx/10wx 0x7fff0000                   # examine 10 words at addressx/s 0x400abc                        # examine as stringx/i $rip                            # examine current instruction
backtrace                           # call stack (bt)bt full                             # bt + local varsframe 2                             # switch to frame 2up / down                           # move up/down the stack

6. Multi-thread debugging

gdb
info threads                        # list threadsthread 3                            # switch to thread 3thread apply all bt                 # backtrace all threadsthread apply all bt full            # full bt all threadsset scheduler-locking on            # pause other threads while stepping

7. Reverse debugging (record/replay)

Record requires target record-full or target record-btrace (Intel PT):

gdb
# Software record (slow but universal)record                              # start recordingrun# ... trigger the bug ...reverse-continue                    # go back to last breakreverse-next                        # step backwardsreverse-stepreverse-finish
# Intel Processor Trace (fast, hardware)target record-btrace ptrun# view instruction historyrecord instruction-history

8. Remote debugging with gdbserver

On target:

bash
gdbserver :1234 ./prog# Or attach:gdbserver :1234 --attach 5678

On host:

bash
gdb ./prog(gdb) target remote 192.168.1.10:1234(gdb) break main(gdb) continue

For cross-compilation: use aarch64-linux-gnu-gdb on the host.

9. Common problems

SymptomCauseFix
No symbol tableBinary not compiled with -gRecompile with -g
?? frames in backtraceMissing debug info or stack corruptionInstall debuginfo package; check for stack smash
Cannot access memory at addressNull dereference / freed memoryCheck pointer before deref; use ASan
SIGABRT in backtraceabort() or assertion failureGo up frames to find the assertion
GDB hangs on runBinary waiting for inputRedirect stdin: run < /dev/null
Breakpoint in wrong placeOptimiser moved codeCompile with -Og; or use nexti

10. GDB init file (~/.gdbinit)

gdb
set history save onset history size 1000set print pretty onset print array onset print array-indexes onset pagination offset confirm off

For a command cheatsheet, see references/cheatsheet.md [blocked]. For pretty-printers and Python scripting, see references/scripting.md [blocked].

Related skills

  • Use skills/debuggers/core-dumps for loading core files
  • Use skills/debuggers/lldb for LLDB-based workflows
  • Use skills/runtimes/sanitizers to catch bugs before needing the debugger
  • Use skills/compilers/gcc for -g flag details

来源与署名

来源：mohitmishra786/low-level-dev-skills位于skills/debuggers/gdb提交bdc5847

许可证： 无许可证

内容归原作者所有。SourceWeft 从公开仓库中收录这些内容。

举报或申请下架

更多来自 mohitmishra786/low-level-dev-skills 的技能

Zig Debugging

mohitmishra786

指导使用 GDB、LLDB 调试 Zig 程序，解读 panic、错误返回追踪、日志记录及 IDE 配置。

Software Development2533个月前更新

Simd Intrinsics

mohitmishra786

指导使用 x86 SSE/AVX 与 ARM NEON 内建函数编写和诊断 SIMD 向量化。

Software Development2533个月前更新

Zig Cross

mohitmishra786

指导 Zig 交叉编译：目标三元组、CPU 特性、用 zig cc 编译 C、嵌入式与 WASM 目标。

Software Development2533个月前更新

Rustc Basics

mohitmishra786

指导 Rust 编译器配置：RUSTFLAGS、Cargo 配置文件、构建调优，以及查看 MIR 或汇编输出。

Software Development2533个月前更新

Zig Cinterop

mohitmishra786

指导 Zig 与 C 互操作：@cImport、translate-c、extern 与 packed 结构体，以及 C/Zig 混合构建。

Software Development2533个月前更新

Zig Build System

mohitmishra786

指导编写和调试 Zig 的 build.zig 文件，涵盖目标、C 源码、选项、测试与包清单。

Software Development2533个月前更新

更多Software Development技能

Playground

anthropics

精选

构建自包含的交互式 HTML 演练场，包含控件、实时预览和可复制的提示词输出。

Software Development37K今天更新

M5 Onboard

anthropics

精选

通过 USB 检测 M5Stack ESP32 开发板，刷写 UIFlow 2.0 固件并安装 MicroPython 应用包。

Software Development37K今天更新

Cardputer Buddy

anthropics

精选

指导迭代 Cardputer-Adv 的 MicroPython 应用包：添加应用、通过 USB 串口推送文件、查看日志并运行 REPL 命令。

Software Development37K今天更新

Web Design Guidelines

vercel-labs

精选

依据从远程来源获取的 Web Interface Guidelines 审查 UI 代码，并以 file:line 形式报告问题。

Software Development32K5周前更新

Vercel React Native Skills

vercel-labs

精选

React Native 与 Expo 最佳实践规则，涵盖列表性能、动画、导航、UI 模式、状态与 monorepo 配置。

Software Development32K5周前更新

Vercel React Best Practices

vercel-labs

精选

Vercel 的 React 与 Next.js 性能指南，以 70 条规则的形式用于编写、审查和重构代码。

Software Development32K5周前更新