[lldb-dap] Provide a way to specify lldb executable

[solomatov]

I use lldb-dap with Rust. Rust has rust-lldb script (https://github.com/rust-lang/rust/blob/master/src/etc/rust-lldb) which setups the environment with correct type visualizations. Nice to be able to set a path to lldb-rust instead of default lldb via settings.json, instead of creating .lldbinit and manually loading required visualizers.

[llvmbot]

@llvm/issue-subscribers-lldb-dap

Author: Konstantin Solomatov (solomatov)

I use lldb-dap with Rust. Rust has rust-lldb script (https://github.com/rust-lang/rust/blob/master/src/etc/rust-lldb) which setups the environment with correct type visualizations. Nice to be able to set a path to lldb-rust instead of default lldb via settings.json, instead of creating .lldbinit and manually loading required visualizers.

[da-viper]

lldb-dap does not used the lldb binary to provide debugging, it uses the lldb-dap binary.
You can change the lldb-dap binary using the setting "lldb-dap.executable-path": "/path/to/lldb-dap/binary"`,

To mimic what the rust-lldb script does you can add the following to your lldb-dap.initCommands: global settings added in #137694

running the following in your shell.

host=$(rustc -vV | sed -n -e 's/^host: //p')
RUSTC_SYSROOT=$(rustc --print sysroot)
script_import="command script import \"$RUSTC_SYSROOT/lib/rustlib/etc/lldb_lookup.py\""
commands_file="$RUSTC_SYSROOT/lib/rustlib/etc/lldb_commands"
# echo $script_import $commands_file to the the file path .

in your settings add

  "lldb-dap.initCommands": [
    "command script import $the_path_to_script_import_file",
    "command source $the_path_to_commands_file"
  ],

replace with the correct path.

[solomatov]

@da-viper Thank you for your reply! I solved this issue in the following way via the .lldbinit file.

command script import "HOME_DIR/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/etc/lldb_lookup.py"
command source -s 0 'HOME_DIR/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/etc/lldb_commands'

However, it requires configuration, and overall non trivial.

It would be great if you could make Rust work out of the box. IMO, it's popular enough to have special support, and you could easily check for the existence of the path from my .lddbinit to find the required init scripts.