title: Problem in VSCode "$gcc" problem matcher to recognize file path in C++ compiler error reports
body: <p>I have just set my launch.json and tasks.json as the tutorial on the Internet said. But when I pree F5 compile and find some errors, I cannot click the red words "errors" showed in the "Problems". 
  <a href="https://i.stack.imgur.com/jGqFY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jGqFY.png" alt="Description"></a></p>
  
  <p>If I click, the information will be:
  <a href="https://i.stack.imgur.com/IoOiM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IoOiM.png" alt="Description"></a></p>
  
  <p>Anyone can help me?</p>
  
  <p><hr/>
  task.json</p>
  
  <pre><code>{
      // https://go.microsoft.com/fwlink/?LinkId=733558
      "version": "2.0.0",
      "tasks": [
          {
              "type": "shell",
              "label": "g++.exe build active file",
              "command": "C:\\MinGW\\bin\\g++.exe",
              "args": [
                  "-g",
                  "${file}",
                  "-o",
                  "${fileDirname}\\${fileBasenameNoExtension}.exe"
              ],
              "options": {
                  "cwd": "C:\\MinGW\\bin"
              },
              "problemMatcher": [
                  "$gcc"
              ],
              "group": "build"
          }
      ]
  }
  </code></pre>