#!/bin/bash -eux
# Copyright 2022 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
################################################################################

# This is a copy of the upstream script which is only needed to link
# additional static libraries. Orignal source:
#
# https://github.com/google/oss-fuzz/blob/9e8dd47cb902545efc60a5580126adc36d70bae3/infra/base-images/base-builder/compile_native_go_fuzzer

function build_native_go_fuzzer() {
	fuzzer=$1
	function=$2
	path=$3
	tags="-tags gofuzz"

	if [[ $SANITIZER == *coverage* ]]; then
		current_dir=$(pwd)
		mkdir $OUT/rawfuzzers || true
		cd $abs_file_dir
		go test -c -run $fuzzer -o $OUT/$fuzzer -cover
		cp "${fuzzer_filename}" "${OUT}/rawfuzzers/${fuzzer}"
		cd $current_dir
	else
		go-118-fuzz-build -o $fuzzer.a -func $function $abs_file_dir
		# TODO: upstream support for linking $ADDITIONAL_LIBS
		$CXX $CXXFLAGS $LIB_FUZZING_ENGINE $fuzzer.a -o $OUT/$fuzzer \
			$ADDITIONAL_LIBS
	fi
}


path=$1
function=$2
fuzzer=$3
tags="-tags gofuzz"

# Get absolute path.
abs_file_dir=$(go list $tags -f {{.Dir}} $path)

# TODO(adamkorcz): Get rid of "-r" flag here.
fuzzer_filename=$(grep -r -l --include='*.go' -s "$function" "${abs_file_dir}")

# Test if file contains a line with "func $function" and "testing.F".
if [ $(grep -r "func $function" $fuzzer_filename | grep "testing.F" | wc -l) -eq 1 ]
then
	build_native_go_fuzzer $fuzzer $function $abs_file_dir
else
	echo "Could not find the function: func ${function}(f *testing.F)"
fi