#!/bin/bash

# ================================================================
# Reads the Miller DSL grammar file and generates Go code.
#
# This is not run on every build / commit / etc.
#
# It's intended to be run manually by the developer, as needed when mlr.bnf
# changes for example.
#
# Resulting auto-generated .go files should then be checked into source control.
#
# With verbose, *.txt files are created with information about LR1 conflicts
# etc.  Please don't commit them.
#
# As of mid-2021 this takes easily 5-10 minutes to run.
# ================================================================

set -euo pipefail

verbose="true"
if [ $# -eq 1 ]; then
  if [ "$1" == "-v" ]; then
    verbose="true"
  elif [ "$1" == "-q" ]; then
    verbose="true"
  fi
fi

# Build the bin/gocc executable (use my fork for performance):
go install github.com/johnkerl/gocc
go mod tidy
bingocc="$HOME/go/bin/gocc"
if [ ! -x "$bingocc" ]; then
  exit 1
fi

rm -f pkg/parsing/*.txt
if [ "$verbose" = "true" ]; then
  lr1="pkg/parsing/LR1_conflicts.txt"
  $bingocc -v -o ./pkg/parsing -p mlr/pkg/parsing pkg/parsing/mlr.bnf || expand -2 $lr1
else
  $bingocc -o ./pkg/parsing -p mlr/pkg/parsing pkg/parsing/mlr.bnf
fi

# Code-gen directories:
#   pkg/parsing/errors/
#   pkg/parsing/lexer/
#   pkg/parsing/parser/
#   pkg/parsing/token/
#   pkg/parsing/util/

# Override GOCC codegen with customized error handling
cp pkg/parsing/errors.go.template pkg/parsing/errors/errors.go

# We might need a manual replace of os.ReadFile by ioutil.ReadFile in autogen code.  Note we don't
# use latest-and-greatest Go compiler version in our go.mod since we want to build on Centos which
# can be trailing-edge in that regard.

for x in pkg/parsing/*/*.go; do gofmt -w $x; done