rust-re2: add wrapper for calling Re2 from Rust
This assumes that Re2 is installed following Google's guide. I am not sure
how we want to integrate it in the project, but I think a follow-up patch would
be more appropriate for such work.
As it stands, *not* having Re2 installed results in a compilation error, which
is a problem as it breaks install compatibility. Hence, this is gated behind
a non-default `with-re2` compilation feature.
Differential Revision: https://phab.mercurial-scm.org/D7910
/*
* mpatch.cc - fuzzer harness for mpatch.c
*
* 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 <iostream>
#include <memory>
#include <stdint.h>
#include <stdlib.h>
#include <vector>
#include "fuzzutil.h"
extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
return 0;
}
// To avoid having too many OOMs from the fuzzer infrastructure, we'll
// skip patch application if the resulting fulltext would be bigger
// than 10MiB.
#define MAX_OUTPUT_SIZE 10485760
extern "C" {
#include "bitmanipulation.h"
#include "mpatch.h"
struct mpatchbin {
std::unique_ptr<char[]> data;
size_t len;
};
static mpatch_flist *getitem(void *vbins, ssize_t pos)
{
std::vector<mpatchbin> *bins = (std::vector<mpatchbin> *)vbins;
const mpatchbin &bin = bins->at(pos + 1);
struct mpatch_flist *res;
LOG(2) << "mpatch_decode " << bin.len << std::endl;
if (mpatch_decode(bin.data.get(), bin.len, &res) < 0)
return NULL;
return res;
}
// input format:
// u8 number of inputs
// one u16 for each input, its length
// the inputs
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
if (!Size) {
return 0;
}
// First byte of data is how many texts we expect, first text
// being the base the rest being the deltas.
ssize_t numtexts = Data[0];
if (numtexts < 2) {
// No point if we don't have at least a base text and a delta...
return 0;
}
// Each text will be described by a byte for how long it
// should be, so give up if we don't have enough.
if ((Size - 1) < (numtexts * 2)) {
return 0;
}
size_t consumed = 1 + (numtexts * 2);
LOG(2) << "input contains " << Size << std::endl;
LOG(2) << numtexts << " texts, consuming " << consumed << std::endl;
std::vector<mpatchbin> bins;
bins.reserve(numtexts);
for (int i = 0; i < numtexts; ++i) {
mpatchbin bin;
size_t nthsize = getbeuint16((char *)Data + 1 + (2 * i));
LOG(2) << "text " << i << " is " << nthsize << std::endl;
char *start = (char *)Data + consumed;
consumed += nthsize;
if (consumed > Size) {
LOG(2) << "ran out of data, consumed " << consumed
<< " of " << Size << std::endl;
return 0;
}
bin.len = nthsize;
bin.data.reset(new char[nthsize]);
memcpy(bin.data.get(), start, nthsize);
bins.push_back(std::move(bin));
}
LOG(2) << "mpatch_flist" << std::endl;
struct mpatch_flist *patch =
mpatch_fold(&bins, getitem, 0, numtexts - 1);
if (!patch) {
return 0;
}
LOG(2) << "mpatch_calcsize" << std::endl;
ssize_t outlen = mpatch_calcsize(bins[0].len, patch);
LOG(2) << "outlen " << outlen << std::endl;
if (outlen < 0 || outlen > MAX_OUTPUT_SIZE) {
goto cleanup;
}
{
char *dest = (char *)malloc(outlen);
LOG(2) << "expecting " << outlen << " total bytes at "
<< (void *)dest << std::endl;
mpatch_apply(dest, bins[0].data.get(), bins[0].len, patch);
free(dest);
LOG(1) << "applied a complete patch" << std::endl;
}
cleanup:
mpatch_lfree(patch);
return 0;
}
} // extern "C"