#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#-------------------------------------------------------------------------------
#     Copyright (C) 2019-2022 OpenCFD Ltd.
#-------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     makeParser
#
# Description
#     Pregenerate ragel code and/or lemon parser headers
#
#------------------------------------------------------------------------------
printHelp() {
    cat<<USAGE

Usage: ${0##*/} [options]

options:
  -prefix=NAME      Common prefix for parser and scanner
  -parser=FILE      Generate lemon parser header
  -scanner=FILE     Generate ragel scanner code
  -code             Generate parser code, not header
  -header           Generate parser header, not code (default)
  -grammar          Output grammar tables (if supported)
  -dry-run          Process m4 only (output on stdout)
  -no-lines         Suppress generation of #line directives
  -no-tmp           Do not retain temporary m4 processed files
  -remove           Remove generated code
  -h, -help         Print the usage

Pregenerate ragel code and/or lemon parser headers

USAGE
    exit 0 # Clean exit
}

#------------------------------------------------------------------------------
# Parse arguments and options
#------------------------------------------------------------------------------

unset prefix parser scanner optHeader optGrammar optDryRun
unset optRemoveFile optRemoveTmp optNoLines
while [ "$#" -gt 0 ]
do
    case "$1" in
    ('') ;;
    (- | --) shift; break ;;  # Stop option parsing

    (-h | -help*) printHelp ;;

    (-prefix=*)   prefix="${1#*=}" ;;
    (-parser=*)   parser="${1#*=}" ;;
    (-scanner=*)  scanner="${1#*=}" ;;

    (-code)       optHeader=false ;;
    (-head*)      optHeader=true ;;
    (-gram*)      optGrammar="-grammar" ;;  # Pass verbatim to wrapper
    (-dry-run)    optDryRun="-dry-run" ;;   # Pass verbatim to wrapper
    (-no-lines)   optNoLines=true ;;
    (-no-tmp)     optRemoveTmp="-no-tmp" ;; # Pass verbatim to wrapper
    (-remove)     optRemoveFile=true ;;

    (*) break ;;
    esac
    shift
done

#------------------------------------------------------------------------------

# Remove file, with feedback. $1 = file, $2 = message
removeFile() {
   if test -f "$1" && rm -f "$1"
   then
       echo "Removed generated $2 file" 1>&2
   else
       echo "No generated $2 file to remove" 1>&2
   fi
}


case "$scanner" in
(*.rl)
    input="${prefix}${scanner}"
    output="${prefix}${scanner%.*}.cc"

    if [ "$optRemoveFile" = true ]
    then
        removeFile "$output"  "ragel scanner"
    elif command -v ragel >/dev/null
    then
        echo "Generating ragel scanner" 1>&2
        ragel -G2 ${optNoLines:+-L} -o "$output" "$input"
    else
        echo "No ragel, leaving scanner intact" 1>&2
    fi
    echo
    ;;
esac


# The output code extension is .c (default) or .cc, but also possibly .C
# - mapping here consistent with wmake/rules/General/{bison,lemon}

extCode=c
case "$parser" in
    (*.Y) extCode=C ;;
    (*.yy | *.yy-m4 | *.lyy | *.lyy-m4) extCode=cc ;;
esac

# Detect m4, any additional messages (eg, using m4 etc)
unset usingM4 message
case "$parser" in
(*m4)
    usingM4=true
    message=", using m4 filtering"
    ;;
esac

case "$parser" in
(*.ly | *.lyy | *.ly-m4 | *.lyy-m4)  # Lemon
    input="${prefix}${parser}"
    output="${parser%.*}.h"

    if [ "$optRemoveFile" = true ]
    then
        removeFile "$output"  "lemon header"
    else

        # Touch parser file time when using m4.
        # This ensures that we have a better correspondence between
        # generated and compiled versions since changes to the m4 macros
        # may otherwise not be noticed.

        if [ "$usingM4" = true ] && [ -f "$input" ]
        then
            message="$message (touching input file time)"
            touch "$input"
        fi

        if [ "$optHeader" = false ]
        then
            echo "Generating lemon parser code ($extCode)$message" 1>&2
            "${WM_PROJECT_DIR:?}/wmake/scripts/wrap-lemon" \
                $optDryRun $optGrammar $optRemoveTmp \
                -e"$extCode" -p -s "$input"
        else
            echo "Generating lemon parser header$message" 1>&2
            "${WM_PROJECT_DIR:?}/wmake/scripts/wrap-lemon" \
                $optDryRun $optGrammar $optRemoveTmp -header \
                -p -s "$input"
        fi
    fi
    echo
    ;;

(*.[Yy] | *.yy | *.y-m4 | *.yy-m4)  # Bison
    input="${prefix}${parser}"

    if [ "$optRemoveFile" = true ]
    then
        echo "File removal not yet supported for bison" 1>&2
    else
        # Touch parser file time when using m4.
        # This ensures that we have a better correspondence between
        # generated and compiled versions since changes to the m4 macros
        # may otherwise not be noticed.

        if [ "$usingM4" = true ] && [ -f "$input" ]
        then
            message="$message (touching input file time)"
            touch "$input"
        fi

        if [ -n "$optDryRun" ]
        then
            echo "Generating bison parser code ($extCode)$message" 1>&2
            "${WM_PROJECT_DIR:?}/wmake/scripts/wrap-bison" \
                $optDryRun $optRemoveTmp "$input"
        else
            echo "Currently only -dry-run is supported for bison" 1>&2
        fi
    fi
    echo
    ;;
esac

#------------------------------------------------------------------------------