http://chestnutheng.github.io/tags/gdb/ Recent content in GDB on 子恒的博客 Hugo zh-CN Sun, 17 Dec 2017 00:56:24 +0800 http://chestnutheng.github.io/gdb/ Sun, 17 Dec 2017 00:56:18 +0800 http://chestnutheng.github.io/gdb/ <h2 id="命令行参数">命令行参数</h2> <p>gdb有下面几种运行方式：</p> <div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code><span class="lnt">1 </span><span class="lnt">2 </span><span class="lnt">3 </span><span class="lnt">4 </span><span class="lnt">5 </span><span class="lnt">6 </span></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-c" data-lang="c"><span class="line"><span class="cl"><span class="c1">// 1. 通过coredump文件，或者存在的进程id分析，不会拉起新进程 </span></span></span><span class="line"><span class="cl"><span class="c1"></span><span class="n">gdb</span> <span class="p">[</span><span class="n">options</span><span class="p">]</span> <span class="p">[</span><span class="n">executable</span><span class="o">-</span><span class="n">file</span> <span class="p">[</span><span class="n">core</span><span class="o">-</span><span class="n">file</span> <span class="n">or</span> <span class="n">process</span><span class="o">-</span><span class="n">id</span><span class="p">]]</span> </span></span><span class="line"><span class="cl"><span class="c1">// 2. 带参数运行程序 </span></span></span><span class="line"><span class="cl"><span class="c1"></span><span class="n">gdb</span> <span class="p">[</span><span class="n">options</span><span class="p">]</span> <span class="o">--</span><span class="n">args</span> <span class="n">executable</span><span class="o">-</span><span class="n">file</span> <span class="p">[</span><span class="n">inferior</span><span class="o">-</span><span class="n">arguments</span> <span class="p">...]</span> </span></span><span class="line"><span class="cl"><span class="c1">// 3. redhat等含有用于调试python的工具 </span></span></span><span class="line"><span class="cl"><span class="c1">// gdb [options] [--python|-P] script-file [script-arguments ...] </span></span></span></code></pre></td></tr></table> </div> </div><p>几个值得注意的参数：</p> <div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code><span class="lnt"> 1 </span><span class="lnt"> 2 </span><span class="lnt"> 3 </span><span class="lnt"> 4 </span><span class="lnt"> 5 </span><span class="lnt"> 6 </span><span class="lnt"> 7 </span><span class="lnt"> 8 </span><span class="lnt"> 9 </span><span class="lnt">10 </span><span class="lnt">11 </span><span class="lnt">12 </span><span class="lnt">13 </span><span class="lnt">14 </span></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-c" data-lang="c"><span class="line"><span class="cl"><span class="c1">// 和上面的类似，使用参数指定的 </span></span></span><span class="line"><span class="cl"><span class="c1"></span><span class="o">--</span><span class="n">args</span> <span class="n">Arguments</span> <span class="n">after</span> <span class="n">executable</span><span class="o">-</span><span class="n">file</span> <span class="n">are</span> <span class="n">passed</span> <span class="n">to</span> <span class="n">inferior</span> </span></span><span class="line"><span class="cl"><span class="o">--</span><span class="n">core</span><span class="o">=</span><span class="n">COREFILE</span> <span class="n">Analyze</span> <span class="n">the</span> <span class="n">core</span> <span class="n">dump</span> <span class="n">COREFILE</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="o">--</span><span class="n">pid</span><span class="o">=</span><span class="n">PID</span> <span class="n">Attach</span> <span class="n">to</span> <span class="n">running</span> <span class="n">process</span> <span class="n">PID</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="o">--</span><span class="n">exec</span><span class="o">=</span><span class="n">EXECFILE</span> <span class="n">Use</span> <span class="n">EXECFILE</span> <span class="n">as</span> <span class="n">the</span> <span class="n">executable</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="c1">// 远程调试 </span></span></span><span class="line"><span class="cl"><span class="c1"></span><span class="o">-</span><span class="n">b</span> <span class="n">BAUDRATE</span> <span class="n">Set</span> <span class="n">serial</span> <span class="n">port</span> <span class="n">baud</span> <span class="n">rate</span> <span class="n">used</span> <span class="k">for</span> <span class="n">remote</span> <span class="n">debugging</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="o">-</span><span class="n">l</span> <span class="n">TIMEOUT</span> <span class="n">Set</span> <span class="n">timeout</span> <span class="n">in</span> <span class="n">seconds</span> <span class="k">for</span> <span class="n">remote</span> <span class="n">debugging</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="c1">// 运行某个文件中的gdb指令 </span></span></span><span class="line"><span class="cl"><span class="c1"></span><span class="o">--</span><span class="n">command</span><span class="o">=</span><span class="n">FILE</span><span class="p">,</span> <span class="o">-</span><span class="n">x</span> <span class="n">Execute</span> <span class="n">GDB</span> <span class="n">commands</span> <span class="n">from</span> <span class="n">FILE</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="c1">// 运行某gdb指令，如gdb a.out -ex r开启文件并立即运行 </span></span></span><span class="line"><span class="cl"><span class="c1"></span><span class="o">--</span><span class="n">eval</span><span class="o">-</span><span class="n">command</span><span class="o">=</span><span class="n">COMMAND</span><span class="p">,</span> <span class="o">-</span><span class="n">ex</span> <span class="n">Execute</span> <span class="n">a</span> <span class="n">single</span> <span class="n">GDB</span> <span class="n">command</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="o">--</span><span class="n">directory</span><span class="o">=</span><span class="n">DIR</span> <span class="n">Search</span> <span class="k">for</span> <span class="n">source</span> <span class="n">files</span> <span class="n">in</span> <span class="n">DIR</span><span class="p">.</span> </span></span><span class="line"><span class="cl"><span class="o">--</span><span class="n">se</span><span class="o">=</span><span class="n">FILE</span> <span class="n">Use</span> <span class="n">FILE</span> <span class="n">as</span> <span class="n">symbol</span> <span class="n">file</span> <span class="n">and</span> <span class="n">executable</span> <span class="n">file</span><span class="p">.</span> </span></span></code></pre></td></tr></table> </div> </div><h2 id="简单的例子coredump分析">简单的例子：coredump分析</h2> <p>gdb的一大用处是通过coredump文件分析程序哪里发生了错误。首先要打开coredump生成开关：</p>