Rust `std` source mappings in VSCode

generate-stdlib-map.sh

#!/usr/bin/env bash
# ============================================================================== #
# MIT License                                                                    #
# ------------------------------------------------------------------------------ #
# Displays the CodeLLDB standard library mapping for debugging Rust binaries.    #
# Generates a JSON string used in VSCode debug task list.                        #
# Requires the `jq` utility to be installed.                                     #
# ============================================================================== #
# OUTPUT:                                                                        #
#   "lldb.launch.sourceMap": {
#      "/rustc/<hash>/": "/home/<username>/<rust-toolchain>/lib/rustlib/src/rust/src",
#   }
# ============================================================================== #

cargo_bin="$(cargo metadata --no-deps --format-version 1 | jq -r -c '.target_directory')"
crates="$(cargo metadata --no-deps --format-version 1 | jq -r -c '.packages[].targets[] | if .kind[0] == "bin" then .name else empty end')"

function srcmap_to() { realpath "$(rustc --print sysroot)/lib/rustlib/src/rust/src"; }
function srcmap_from() { strings target/debug/$1 | grep -o '^/rustc/[^/]\+/' | uniq; }

echo "\"lldb.launch.sourceMap\": {"

for target in `echo $crates`; do
    target_path="$(realpath $cargo_bin/debug/$target)"
    if [ -f "${target_path}" ]; then
        echo "    \"$(srcmap_from $target)\": \"$(srcmap_to)\","
    fi
done

echo "}"