fuzz: fix xdiff build

Recent xdiff code cleanups removed some files and changed some structures.
Update fuzz code.

Differential Revision: https://phab.mercurial-scm.org/D2707

contrib/fuzz/Makefile

@@ -1,40 +1,40
 bdiff.o: ../../mercurial/bdiff.c
 	clang -g -O1 -fsanitize=fuzzer-no-link,address -c -o bdiff.o \
 	  ../../mercurial/bdiff.c
 
 bdiff: bdiff.cc bdiff.o
 	clang -DHG_FUZZER_INCLUDE_MAIN=1 -g -O1 -fsanitize=fuzzer-no-link,address \
 	  -I../../mercurial bdiff.cc bdiff.o -o bdiff
 
 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++11 -I../../mercurial bdiff.cc \
 	  bdiff-oss-fuzz.o -lFuzzingEngine -o $$OUT/bdiff_fuzzer
 
 x%.o: ../../mercurial/thirdparty/xdiff/x%.c ../../mercurial/thirdparty/xdiff/*.h
 	clang -g -O1 -fsanitize=fuzzer-no-link,address -c \
 	  -o $@ \
 	  $<
 
-xdiff: xdiff.cc xdiffi.o  xemit.o  xmerge.o  xprepare.o  xutils.o
+xdiff: xdiff.cc xdiffi.o xprepare.o  xutils.o
 	clang -DHG_FUZZER_INCLUDE_MAIN=1 -g -O1 -fsanitize=fuzzer-no-link,address \
 	  -I../../mercurial xdiff.cc \
-	  xdiffi.o xemit.o xmerge.o xprepare.o xutils.o -o xdiff
+	  xdiffi.o xprepare.o xutils.o -o xdiff
 
 fuzz-x%.o: ../../mercurial/thirdparty/xdiff/x%.c ../../mercurial/thirdparty/xdiff/*.h
 	$$CC $$CFLAGS -c \
 	  -o $@ \
 	  $<
 
-xdiff_fuzzer: xdiff.cc fuzz-xdiffi.o  fuzz-xemit.o  fuzz-xmerge.o  fuzz-xprepare.o  fuzz-xutils.o
+xdiff_fuzzer: xdiff.cc fuzz-xdiffi.o fuzz-xprepare.o  fuzz-xutils.o
 	$$CXX $$CXXFLAGS -std=c++11 -I../../mercurial xdiff.cc \
-	  fuzz-xdiffi.o fuzz-xemit.o fuzz-xmerge.o fuzz-xprepare.o fuzz-xutils.o \
+	  fuzz-xdiffi.o fuzz-xprepare.o fuzz-xutils.o \
 	  -lFuzzingEngine -o $$OUT/xdiff_fuzzer
 
 all: bdiff xdiff
 
 oss-fuzz: bdiff_fuzzer xdiff_fuzzer
 
 .PHONY: all oss-fuzz

contrib/fuzz/xdiff.cc

@@ -1,67 +1,60
 /*
  * xdiff.cc - fuzzer harness for thirdparty/xdiff
  *
  * Copyright 2018, Google Inc.
  *
  * This software may be used and distributed according to the terms of
  * the GNU General Public License, incorporated herein by reference.
  */
 #include "thirdparty/xdiff/xdiff.h"
 #include <inttypes.h>
 #include <stdlib.h>
 
 extern "C" {
 
 int hunk_consumer(long a1, long a2, long b1, long b2, void *priv)
 {
 	// TODO: probably also test returning -1 from this when things break?
 	return 0;
 }
 
 int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
 {
 	if (!Size) {
 		return 0;
 	}
 	// figure out a random point in [0, Size] to split our input.
 	size_t split = Data[0] / 255.0 * Size;
 
 	mmfile_t a, b;
 
 	// `a` input to diff is data[1:split]
 	a.ptr = (char *)Data + 1;
 	// which has len split-1
 	a.size = split - 1;
 	// `b` starts at the next byte after `a` ends
 	b.ptr = a.ptr + a.size;
 	b.size = Size - split;
 	xpparam_t xpp = {
 	    XDF_INDENT_HEURISTIC, /* flags */
-	    NULL,                 /* anchors */
-	    0,                    /* anchors_nr */
 	};
 	xdemitconf_t xecfg = {
-	    0,                  /* ctxlen */
-	    0,                  /* interhunkctxlen */
 	    XDL_EMIT_BDIFFHUNK, /* flags */
-	    NULL,               /* find_func */
-	    NULL,               /* find_func_priv */
 	    hunk_consumer,      /* hunk_consume_func */
 	};
 	xdemitcb_t ecb = {
 	    NULL, /* priv */
-	    NULL, /* outf */
 	};
 	xdl_diff(&a, &b, &xpp, &xecfg, &ecb);
 	return 0; // Non-zero return values are reserved for future use.
 }
 
 #ifdef HG_FUZZER_INCLUDE_MAIN
 int main(int argc, char **argv)
 {
 	const char data[] = "asdf";
 	return LLVMFuzzerTestOneInput((const uint8_t *)data, 4);
 }
 #endif
 
 } // extern "C"