vscode vhdl build and problem matcher

tasks.json

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "0.1.0",
    "command": "cmd",
    "isShellCommand": true,
    "args": ["/c"],
    "showOutput": "silent",
    "tasks" : [
        {
            "taskName": "vsimbuild",
            "args" : ["vcom ${file}"],
            "isBuildCommand": true,
            "suppressTaskName": true,
             "problemMatcher": {
            "fileLocation": ["relative", "${workspaceRoot}"],
             "owner":"vhd",
            "pattern": {
           "regexp":  "\\s+(Error|Warning).*:.*\\\\(.*\\..*)\\((.\\d)\\):(.*)",
            "severity": 1,
            "file": 2,
            "line": 3,
            "message":4
            }
        } 
    }
    ]
}