Admin/check_ml_headers

more robust (amending 1600fb749c54), to support the following corner case:
schematic_goal "PROP ((?f :: ?'a \<Rightarrow> _) (x :: ?'a))"
apply (tactic \<open>PRIMITIVE (Thm.instantiate (TVars.make1 ((("'a", 0), []), @{ctyp prop}), Vars.empty))\<close>)
oops

#!/usr/bin/env bash
#
# check_ml_headers - check headers of *.ML files in distribution for inconsistencies
#
# requires some GNU tools
#

ONLY_FILENAMES=""
if [ "$1" == "-o" ]
then
  ONLY_FILENAMES=1
fi

REPORT_EMPTY=""
if [ "$2" == "-e" ]
then
  REPORT_EMPTY=1
fi

ISABELLE_SRC="$(isabelle getenv -b ISABELLE_HOME)/src/"

for LOC in $(find "$ISABELLE_SRC" -name "*.ML")
do
  TITLE="$(head -n 1 "$LOC" | grep -Po '(?<=Title:)\s*\S+.ML' | grep -Po '\S+.ML')"
  FILELOC="${LOC:${#ISABELLE_SRC}}"
  if [ "$TITLE" != "$FILELOC" ]
  then
    if [ -n "$TITLE" -o \( -n "$REPORT_EMPTY" -a $(basename "$FILELOC") != "ROOT.ML" \) ]
    then
      if [ -z "$ONLY_FILENAMES" ]
      then
        echo "Inconsistency in $LOC: $TITLE"
      else
        echo "$LOC"
      fi
    fi
  fi
done