Bash-compatible stack traces (trap ERR, BASH_ARGV, extdebug)

[andychu]

Probably won't because we don't have trap ERR yet

https://lobste.rs/s/ajoaje/first_two_statements_your_bash_script#c_u6hdcf

trap 'stacktrace "Error trapped rc=${PIPESTATUS[@]}, see trace above"' ERR

stacktrace() {
  local frame="${#FUNCNAME[@]}"
  echo >&2 "Stacktrace:"
  while [[ "${frame}" -gt 1 ]]; do
    ((frame--))
    echo >&2 "  File ${BASH_SOURCE[$frame]}#L${BASH_LINENO[$((frame - 1))]} (in ${FUNCNAME[$frame]}())"
  done
  if [[ "$#" -gt 0 ]]; then
    echo >&2 "$1"
  fi
}

[akinomyoga]

As for the implementation of stacktrace, the implementation by ble.sh might be more useful. It supports BASH_ARGV (set by extdebug).

_ble_util_stackdump_title=stackdump
function ble/util/stackdump {
  ((bleopt_internal_stackdump_enabled)) || return 1
  local message=$1
  local i nl=$'\n'
  local message="$_ble_term_sgr0$_ble_util_stackdump_title: $message$nl"
  local iarg=$BASH_ARGC args= extdebug=
  shopt -q extdebug 2>/dev/null && extdebug=1
  for ((i=1;i<${#FUNCNAME[*]};i++)); do
    if [[ $extdebug ]] && ((BASH_ARGC[i])); then
      args=("${BASH_ARGV[@]:iarg:BASH_ARGC[i]}")
      ble/array#reverse args
      args=" ${args[*]}"
      ((iarg+=BASH_ARGC[i]))
    else
      args=
    fi
    message="$message  @ ${BASH_SOURCE[i]}:${BASH_LINENO[i-1]} (${FUNCNAME[i]}$args)$nl"
  done
  ble/util/put "$message"
}

[andychu]

Note #709 has a code snippet with set -E / errtrace