fuzz/coverage

#!/bin/sh
# Copyright 2017 Google Inc.
#
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

if [ -z "$1" ]; then
	cat <<-EOM
	Usage:
	  $0 [afl-out-loc]

	Run something like this:
	  $0 ~/afl-out
	where afl-out is the directory containing all the output of the afl-fuzzers.
	You can typically ssh into skia-fuzzer-be-1 and skia-fuzzer-be-2 and run
	tar -czf afl-out.tar.gz /mnt/ssd0/fuzzes/afl-out/*/fuzzer0/queue
	and extract it locally to get the directories needed to assess coverage.

	EOM
	exit 1
fi

set -x
set -e

cd "$(dirname "$0")/.."

EXECUTABLE="fuzz"

DIR="$(mktemp -d "${TMPDIR:-/tmp}/skia_coverage_XXXXXXXXXX")"
BUILD=out/coverage

# Build $EXECUTABLE
bin/sync
bin/fetch-gn

rm -rf $BUILD

#TODO: make this work with Clang.
ARGS='cc="gcc" cxx="g++" extra_cflags=["--coverage"] extra_ldflags=["--coverage"]'
gn gen --args="$ARGS" "$BUILD"

ninja -C "$BUILD" "$EXECUTABLE"

GCOV="$(realpath tools/gcov_shim)"

# Generate a zero-baseline so files not covered by $EXECUTABLE $@ will
# still show up in the report.  This reads the .gcno files that are
# created at compile time.
lcov -q --gcov-tool="$GCOV" -c -b "$BUILD" -d "$BUILD" -o "$DIR"/baseline -i

# Running the binary generates the real coverage information, the .gcda files.
QUEUES=("$1/api_parse_path/fuzzer0/queue/*" "$1/color_deserialize/fuzzer0/queue/*" "$1/skcodec_scale/fuzzer0/queue/*" "$1/skcodec_mode/fuzzer0/queue/*" "$1/api_draw_functions/fuzzer0/queue/*" "$1/api_gradient/fuzzer0/queue/*" "$1/api_image_filter/fuzzer0/queue/*" "$1/api_pathop/fuzzer0/queue/*" "$1/sksl2glsl/fuzzer0/queue/*" "$1/null_canvas/fuzzer0/queue/*" "$1/pdf_canvas/fuzzer0/queue/*" "$1/n32_canvas/fuzzer0/queue/*")

ARGS=("-n ParsePath" "-t color_deserialize" "-t image_scale" "-t image_mode" "-n DrawFunctions" "-n Gradients" "-n SerializedImageFilter" "-n Pathop" "-t sksl2glsl" "-n NullCanvas" "-n PDFCanvas" "-n RasterN32Canvas")

# We can't simply pass the directories to the fuzzers because some of the fuzzes will
# crash or assert, which would kill the call to fuzz prematurely. Instead we run them
# individually using the loops below.
for i in `seq ${#QUEUES[@]}`
do
	FILES=${QUEUES[i]}
	for f in $FILES
	do
		# Executing the fuzzes sequentially would take a very long time. So, we run them
		# in the background, making sure we don't go crazy and execute them too fast or
		# that they execute for a long time.
		timeout 10 $BUILD/$EXECUTABLE ${ARGS[i]}  -b $f &
		sleep .005s
	done
done

sleep 10s

echo "done running the fuzzes -- generating report"

lcov -q --gcov-tool="$GCOV" -c -b "$BUILD" -d "$BUILD" -o "$DIR"/coverage

lcov -q -a "$DIR"/baseline -a "$DIR"/coverage -o "$DIR"/merged

genhtml -q "$DIR"/merged --legend -o "$DIR"/coverage_report --ignore-errors source

xdg-open "$DIR"/coverage_report/index.html