bazel: refactor shell rules into own package

Signed-off-by: Paul Meyer <49727155+katexochen@users.noreply.github.com>

bazel/sh/lib.bash

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+set -o errtrace
+shopt -s inherit_errexit
+
+function printErr {
+  echo -e "\033[0;31mERROR:\033[0m ${1}"
+}
+
+function _exitHandler {
+  local exit_code=$1
+  if [[ ${exit_code} -ne 0 ]]; then
+    printErr "$0: exit status ${exit_code}"
+  fi
+}
+
+function _errorHandler {
+  local line=$1
+  local linecallfunc=$2
+  local command="$3"
+  local funcstack="$4"
+  printErr "$0: '${command}' failed at line ${line}"
+
+  if [[ ${funcstack} != "::" ]]; then
+    echo -ne "\tin ${funcstack} "
+    if [[ ${linecallfunc} != "" ]]; then
+      echo "called at line ${linecallfunc}"
+    else
+      echo
+    fi
+  fi
+
+}
+
+_exitHandlers=()
+_errorHandlers=()
+
+function registerExitHandler {
+  _exitHandlers+=("$1")
+}
+
+function registerErrorHandler {
+  _errorHandler+=("$1")
+}
+
+function _callExitHandlers {
+  _exitHandlers+=(_exitHandler) # Add our handler last.
+  for h in "${_exitHandlers[@]}"; do
+    ${h} "$@"
+  done
+}
+
+function _callErrorHandlers {
+  _errorHandlers+=(_errorHandler) # Add our handler last.
+  for h in "${_errorHandlers[@]}"; do
+    ${h} "$@"
+  done
+}
+
+trap '_callErrorHandlers $LINENO $BASH_LINENO "$BASH_COMMAND" $(printf "::%s" ${FUNCNAME[@]:-})' ERR
+trap '_callExitHandlers $?' EXIT