contrib/fuzz/Makefile

documentation: add some internals documentation about bid merge

This is an important algorithm that was only documented on the wiki so far.

Some update to the algorithm (and associated doc) is to expected in the future
since the bid merge algorithm is bug-ridden when it comes to file deletion comes
to play.

Differential Revision: https://phab.mercurial-scm.org/D8711

CC = clang
CXX = clang++

# By default, use our own standalone_fuzz_target_runner.
# This runner does no fuzzing, but simply executes the inputs
# provided via parameters.
# Run e.g. "make all LIB_FUZZING_ENGINE=/path/to/libFuzzer.a"
# to link the fuzzer(s) against a real fuzzing engine.
#
# OSS-Fuzz will define its own value for LIB_FUZZING_ENGINE.
LIB_FUZZING_ENGINE ?= standalone_fuzz_target_runner.o

PYTHON_CONFIG ?= $$OUT/sanpy/bin/python-config
PYTHON_CONFIG_FLAGS ?= --ldflags

CXXFLAGS += -Wno-deprecated-register

all: standalone_fuzz_target_runner.o oss-fuzz

standalone_fuzz_target_runner.o: standalone_fuzz_target_runner.cc

$$OUT/%_fuzzer_seed_corpus.zip: %_corpus.py
	python $< $@

pyutil.o: pyutil.cc pyutil.h
	$(CXX) $(CXXFLAGS) -g -O1 \
	  `$(PYTHON_CONFIG) --cflags` \
	  -I../../mercurial -c -o pyutil.o pyutil.cc

bdiff-oss-fuzz.o: ../../mercurial/bdiff.c
	$(CC) $(CFLAGS) -c -o bdiff-oss-fuzz.o ../../mercurial/bdiff.c

bdiff_fuzzer: bdiff.cc bdiff-oss-fuzz.o
	$(CXX) $(CXXFLAGS) -std=c++17 -I../../mercurial bdiff.cc \
	  bdiff-oss-fuzz.o $(LIB_FUZZING_ENGINE) -o \
	  $$OUT/bdiff_fuzzer

mpatch.o: ../../mercurial/mpatch.c
	$(CC) -g -O1 -fsanitize=fuzzer-no-link,address -c -o mpatch.o \
	  ../../mercurial/mpatch.c

mpatch-oss-fuzz.o: ../../mercurial/mpatch.c
	$(CC) $(CFLAGS) -c -o mpatch-oss-fuzz.o ../../mercurial/mpatch.c

mpatch_fuzzer: mpatch.cc mpatch-oss-fuzz.o $$OUT/mpatch_fuzzer_seed_corpus.zip
	$(CXX) $(CXXFLAGS) -std=c++17 -I../../mercurial mpatch.cc \
	  mpatch-oss-fuzz.o $(LIB_FUZZING_ENGINE) -o \
	  $$OUT/mpatch_fuzzer

fuzz-x%.o: ../../mercurial/thirdparty/xdiff/x%.c ../../mercurial/thirdparty/xdiff/*.h
	$(CC) $(CFLAGS) -c \
	  -o $@ \
	  $<

xdiff_fuzzer: xdiff.cc fuzz-xdiffi.o fuzz-xprepare.o fuzz-xutils.o 
	$(CXX) $(CXXFLAGS) -std=c++17 -I../../mercurial xdiff.cc \
	  fuzz-xdiffi.o fuzz-xprepare.o fuzz-xutils.o \
	  $(LIB_FUZZING_ENGINE) -o $$OUT/xdiff_fuzzer

parsers-%.o: ../../mercurial/cext/%.c
	$(CC) -I../../mercurial `$(PYTHON_CONFIG) --cflags` $(CFLAGS) -c \
	  -o $@ $<

PARSERS_OBJS=parsers-manifest.o parsers-charencode.o parsers-parsers.o parsers-dirs.o parsers-pathencode.o parsers-revlog.o

dirs_fuzzer: dirs.cc pyutil.o $(PARSERS_OBJS) $$OUT/dirs_fuzzer_seed_corpus.zip
	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
	  -Wno-register -Wno-macro-redefined \
	  -I../../mercurial dirs.cc \
	  pyutil.o $(PARSERS_OBJS) \
	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
	  -o $$OUT/dirs_fuzzer

fncache_fuzzer: fncache.cc 
	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
	  -Wno-register -Wno-macro-redefined \
	  -I../../mercurial fncache.cc \
	  pyutil.o $(PARSERS_OBJS) \
	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
	  -o $$OUT/fncache_fuzzer

jsonescapeu8fast_fuzzer: jsonescapeu8fast.cc pyutil.o $(PARSERS_OBJS)
	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
	  -Wno-register -Wno-macro-redefined \
	  -I../../mercurial jsonescapeu8fast.cc \
	  pyutil.o $(PARSERS_OBJS) \
	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
	  -o $$OUT/jsonescapeu8fast_fuzzer

manifest_fuzzer: manifest.cc pyutil.o $(PARSERS_OBJS) $$OUT/manifest_fuzzer_seed_corpus.zip
	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
	  -Wno-register -Wno-macro-redefined \
	  -I../../mercurial manifest.cc \
	  pyutil.o $(PARSERS_OBJS) \
	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
	  -o $$OUT/manifest_fuzzer

revlog_fuzzer: revlog.cc pyutil.o $(PARSERS_OBJS) $$OUT/revlog_fuzzer_seed_corpus.zip
	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
	  -Wno-register -Wno-macro-redefined \
	  -I../../mercurial revlog.cc \
	  pyutil.o $(PARSERS_OBJS) \
	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
	  -o $$OUT/revlog_fuzzer

dirstate_fuzzer: dirstate.cc pyutil.o $(PARSERS_OBJS) $$OUT/dirstate_fuzzer_seed_corpus.zip
	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
	  -Wno-register -Wno-macro-redefined \
	  -I../../mercurial dirstate.cc \
	  pyutil.o $(PARSERS_OBJS) \
	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
	  -o $$OUT/dirstate_fuzzer

fm1readmarkers_fuzzer: fm1readmarkers.cc pyutil.o $(PARSERS_OBJS) $$OUT/fm1readmarkers_fuzzer_seed_corpus.zip
	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
	  -Wno-register -Wno-macro-redefined \
	  -I../../mercurial fm1readmarkers.cc \
	  pyutil.o $(PARSERS_OBJS) \
	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
	  -o $$OUT/fm1readmarkers_fuzzer

clean:
	$(RM) *.o *_fuzzer \
	  bdiff \
	  mpatch \
	  xdiff

oss-fuzz: bdiff_fuzzer mpatch_fuzzer xdiff_fuzzer dirs_fuzzer fncache_fuzzer jsonescapeu8fast_fuzzer manifest_fuzzer revlog_fuzzer dirstate_fuzzer fm1readmarkers_fuzzer

.PHONY: all clean oss-fuzz