Unable to use pre - launch task more than once in VS Code

Question

I'm trying to use pre-launch task more than once to execute two different tasks in my launch.json file. Unfortunately, it only executes the last pre-launch task in my launch.json file. The tasks that are in my tasks.json use the same command("g++") to compile my program, but their arguments are different (that's because I need to compile my source code first into an "O" file then compile the "O" file into an "exe" file), so I'm finding a way on how can I execute those two tasks in the launch.json file using one pre-launch task only. Any other ideas please?

tasks.json:

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "0.1.0",
    "tasks": [
        {
            "taskName": "CompileToOfile",
            "command": "g++",
            "args": [
                "-c","${fileBasename}",
                "-o","${fileBasenameNoExtension}.o",
                "-I","/Users/Acer/MinGW64/include",
                "-I","/Users/Acer/MinGW64/x86_64-w64-mingw32/include",
                "-I","/Users/Acer/MinGW64/lib/gcc/x86_64-w64-mingw32/4.9.2/include",
                "-I","/Users/Acer/MinGW64/lib/gcc/x86_64-w64-mingw32/4.9.2/include/c++",
                "-m32"
            ],
            "isShellCommand": true
        },
        {
            "taskName": "CompileWGDBWBGI",
            "command": "g++",
            "args": [
                "${fileBasenameNoExtension}.o",
                "-o",
                "${fileBasenameNoExtension}.exe",
                "-L","/Users/Acer/MinGW64/lib32",
                "-L","Users/Acer/MinGW64/x86_64-w64-mingw32/lib32",
                "-static-libgcc",
                "-lbgi",
                "-lgdi32",
                "-lcomdlg32",
                "-luuid",
                "-loleaut32",
                "-lole32",
                "-m32"
            ],
            "isShellCommand": true
        }
    ]
}

launch.json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "(Windows) Launch",
            "type": "cppvsdbg",
            "request": "launch",
            "preLaunchTask": "CompileToOfile",
            "preLaunchTask": "CompileWGDBWBGI",
            "program": "${workspaceRoot}/${fileBasenameNoExtension}.exe",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceRoot}",
            "environment": [],
            "externalConsole": true
        },
        {
            "name": "(gdb) Launch",
            "type": "cppdbg",
            "request": "launch",
            "preLaunchTask": "CompileToOfile",
            "preLaunchTask": "CompileWGDBWBGI",
            "program": "${workspaceRoot}/${fileBasenameNoExtension}.exe",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceRoot}",
            "environment": [],
            "externalConsole": true,
            "MIMode": "gdb",
            "miDebuggerPath": "/Users/Acer/MinGW64/bin/gdb.exe",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                }
            ]
        }
    ]
}

Answer 1

You can only have one preLaunchTask, but you could add "dependsOn": "CompileToOfile" to your CompileWGDBWBGI task and then use that as your preLaunchTask. This way, CompileToOfile is executed before each execution of CompileWGDBWBGI.