#!/bin/bash
set -e

if [[ "$(uname -s)" != Linux ]]; then
  echo "Fuzzing is only supported on Linux"
  exit 1
fi

CC=${CC:-clang}
CXX=${CXX:-clang++}

default_fuzz_flags="-fsanitize=fuzzer,address,undefined"

CFLAGS=${CFLAGS:-"$default_fuzz_flags"}
CXXFLAGS=${CXXFLAGS:-"$default_fuzz_flags"}

export CFLAGS
make CC="$CC" CXX="$CXX"

if [ -z "$@" ]; then
  languages=$(ls test/fixtures/grammars)
else
  languages="$@"
fi

mkdir -p test/fuzz/out

for lang in ${languages[@]}; do
  # skip typescript
  if [[ $lang == "typescript" ]]; then
	continue
  fi
  echo "Building $lang fuzzer..."
  lang_dir="test/fixtures/grammars/$lang"

  # The following assumes each language is implemented as src/parser.c plus an
  # optional scanner in src/scanner.{c,cc}
  objects=()

  lang_scanner="${lang_dir}/src/scanner"
  if [ -e "${lang_scanner}.cc" ]; then
    $CXX $CXXFLAGS -g -O1 "-I${lang_dir}/src" -c "${lang_scanner}.cc" -o "${lang_scanner}.o"
    objects+=("${lang_scanner}.o")
  elif [ -e "${lang_scanner}.c" ]; then
    $CC $CFLAGS -std=c11 -g -O1 "-I${lang_dir}/src" -c "${lang_scanner}.c" -o "${lang_scanner}.o"
    objects+=("${lang_scanner}.o")
  fi


  # Compiling with -O0 speeds up the build dramatically
  $CC $CFLAGS -g -O0 "-I${lang_dir}/src" "${lang_dir}/src/parser.c" -c -o "${lang_dir}/src/parser.o"
  objects+=("${lang_dir}/src/parser.o")

  highlights_filename="${lang_dir}/queries/highlights.scm"
  if [ -e "${highlights_filename}" ]; then
    ts_lang_query_filename="${lang}.scm"
    cp "${highlights_filename}" "test/fuzz/out/${ts_lang_query_filename}"
  else
    ts_lang_query_filename=""
  fi

  # FIXME: We should extract the grammar name from grammar.js. Use the name of
  # the directory instead. Also, the grammar name needs to be a valid C
  # identifier so replace any '-' characters
  ts_lang="tree_sitter_$(echo "$lang" | tr -- - _)"
  $CXX $CXXFLAGS -std=c++11 -I lib/include -D TS_LANG="$ts_lang" -D TS_LANG_QUERY_FILENAME="\"${ts_lang_query_filename}\"" \
    "test/fuzz/fuzzer.cc" "${objects[@]}" \
    libtree-sitter.a \
    -o "test/fuzz/out/${lang}_fuzzer"

  jq '
    [ ..
      | if .type? == "STRING" or (.type? == "ALIAS" and .named? == false) then .value else empty end
      | select(test("\\S") and length == utf8bytelength)
    ] | unique | .[]
  ' | sort
done