fuzz: add config knob for PYTHON_CONFIG_FLAGS

I'll clean this up once we get oss-fuzz to use Python 3.8 instead of
2.7, but for now we need a way to evolve the flags passed to
python-config in lockstep with the Python version. Yuck.

Differential Revision: https://phab.mercurial-scm.org/D8637

contrib/fuzz/Makefile

@@ -1,129 +1,130 b''
 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) $$OUT/dirs_fuzzer_seed_corpus.zip
 	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
 	  -Wno-register -Wno-macro-redefined \
 	  -I../../mercurial dirs.cc \
 	  pyutil.o $(PARSERS_OBJS) \
-	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) --ldflags` \
+	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
 	  -o $$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) --ldflags` \
+	  $(LIB_FUZZING_ENGINE) `$(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) --ldflags` \
+	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
 	  -o $$OUT/jsonescapeu8fast_fuzzer
 
 manifest_fuzzer: manifest.cc pyutil.o $(PARSERS_OBJS) $$OUT/manifest_fuzzer_seed_corpus.zip
 	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
 	  -Wno-register -Wno-macro-redefined \
 	  -I../../mercurial manifest.cc \
 	  pyutil.o $(PARSERS_OBJS) \
-	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) --ldflags` \
+	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
 	  -o $$OUT/manifest_fuzzer
 
 revlog_fuzzer: revlog.cc pyutil.o $(PARSERS_OBJS) $$OUT/revlog_fuzzer_seed_corpus.zip
 	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
 	  -Wno-register -Wno-macro-redefined \
 	  -I../../mercurial revlog.cc \
 	  pyutil.o $(PARSERS_OBJS) \
-	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) --ldflags` \
+	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
 	  -o $$OUT/revlog_fuzzer
 
 dirstate_fuzzer: dirstate.cc pyutil.o $(PARSERS_OBJS) $$OUT/dirstate_fuzzer_seed_corpus.zip
 	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
 	  -Wno-register -Wno-macro-redefined \
 	  -I../../mercurial dirstate.cc \
 	  pyutil.o $(PARSERS_OBJS) \
-	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) --ldflags` \
+	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
 	  -o $$OUT/dirstate_fuzzer
 
 fm1readmarkers_fuzzer: fm1readmarkers.cc pyutil.o $(PARSERS_OBJS) $$OUT/fm1readmarkers_fuzzer_seed_corpus.zip
 	$(CXX) $(CXXFLAGS) `$(PYTHON_CONFIG) --cflags` \
 	  -Wno-register -Wno-macro-redefined \
 	  -I../../mercurial fm1readmarkers.cc \
 	  pyutil.o $(PARSERS_OBJS) \
-	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) --ldflags` \
+	  $(LIB_FUZZING_ENGINE) `$(PYTHON_CONFIG) $(PYTHON_CONFIG_FLAGS)` \
 	  -o $$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