Support pretty printing for C++ debug in MacOS

[jiangtann]

I'm using macOS 12 Monterey and g++-11 installed by homebrew with latest VScode and CodeLLDB, the STL output is messy:

And when I use Windows 11 and gcc/gdb with latest C/C++ extension provided by Microsoft, after I add the following configurations at launch.json (which is useless for CodeLLDB in MacOS):

"setupCommands": [
        { 
            "text": "-enable-pretty-printing",
            "description": "enable pretty printing", 
            "ignoreFailures": true 
        }
]

The STL output is delightful:

Here is my configurations in MacOS:
launch.json

{
    "configurations": [
        {
            "type": "lldb",
            "request": "launch",
            "name": "Launch",
            "program": "${fileDirname}/${fileBasenameNoExtension}",
            "args": [],
            "cwd": "${workspaceFolder}",
            "preLaunchTask": "compile",
        }
    ]
} 

task.json

{
    "tasks": [
        {
            "type": "process",
            "label": "compile",
            "command": "/opt/homebrew/bin/g++-11",
            "args": [
                "-g",
                "${file}",
                "-o",
                "${fileDirname}/${fileBasenameNoExtension}",
            ]
        }
    ],
    "version": "2.0.0"
}

Is there any way to make CodeLLDB support pretty printing in MacOS?

[vadimcn]

Data structure visualization in LLDB is achieved via data formatters. I don't maintain LLDB's formatters for C++, I just include whatever upstream LLDB provides. As far as I know, LLDB has formatters for both gcc's libstdc++ and clang's libc++, however on macOS it probably assumes that libc++ is used since clang is the native compiler on that OS. Maybe ask on StackOverflow?

And when I use Windows 11 and gcc/gdb [...]

gcc and gdb are parts of the same toolchain, so this combination had better work...

[jiangtann]

Clang does have better printing when debugging. And the reason why I use gcc instead of clang is that clang inlined more STL functions, which makes debug more difficult. For example:
GCC

Clang

It says:

expression failed to parse:
error: Couldn't lookup symbols:
  __ZNKSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEE6substrEmm

I have tried adding arguments like -O0 but it doesn't help.

Do you know how to prevent STL functions from being inlined when compiling?

[vadimcn]

Whatever this is is likely to be LLDB's built-in behavior. Not really under my control.

[conradsoon]

For anyone else still looking for a solution, adding -gdwarf-4 as a compilation option as suggested here while compiling works for me on macOS Monterey with gcc++-12 installed via homebrew.