Mercurial > hg
annotate contrib/fuzz/xdiff.cc @ 43813:5a9e2ae9899b
fuzz: use a more standard approach to allow local builds of fuzzers
This is taken from the (improved since we started fuzzing) guide on ideal
integrations. Rather than have our own wonky targets for building outside the
fuzzer universe, we have a driver program we carry along and use when we're
not using LibFuzzer. This will let us jettison a fair amount of goo.
contrib/fuzz/standalone_fuzz_target_runner.cc is
https://github.com/google/oss-fuzz/ file
projects/example/my-api-repo/standalone from git revision
c4579d9358a73ea5dbcc99cb985de1f2bf76dcf7, reformatted with out
clang-format settings and a no-check-code comment added. It allows
running a single test input through a fuzzer, rather than performing
ongoing fuzzing as libfuzzer would.
contrib/fuzz/FuzzedDataProvider.h is
https://github.com/llvm/llvm-project/ file
/compiler-rt/include/fuzzer/FuzzedDataProvider.h from git revision
a44ef027ebca1598892ea9b104d6189aeb3bc2f0, reformatted with our
clang-format settings and a no-check-code comment added. We can
discard this if we instead want to add an hghave check for a new
enough llvm that includes FuzzedDataProvder.h in the fuzzer headers.
Differential Revision: https://phab.mercurial-scm.org/D7564
author | Augie Fackler <augie@google.com> |
---|---|
date | Fri, 06 Dec 2019 15:19:47 -0500 |
parents | 51a99e09c54b |
children | d37658efbec2 |
rev | line source |
---|---|
36679 | 1 /* |
2 * xdiff.cc - fuzzer harness for thirdparty/xdiff | |
3 * | |
4 * Copyright 2018, Google Inc. | |
5 * | |
6 * This software may be used and distributed according to the terms of | |
7 * the GNU General Public License, incorporated herein by reference. | |
8 */ | |
9 #include "thirdparty/xdiff/xdiff.h" | |
10 #include <inttypes.h> | |
11 #include <stdlib.h> | |
12 | |
43813
5a9e2ae9899b
fuzz: use a more standard approach to allow local builds of fuzzers
Augie Fackler <augie@google.com>
parents:
43809
diff
changeset
|
13 #include "FuzzedDataProvider.h" |
38173
fa0ddd5e8fff
fuzz: extract some common utilities and use modern C++ idioms
Augie Fackler <augie@google.com>
parents:
36765
diff
changeset
|
14 |
36679 | 15 extern "C" { |
16 | |
43809
51a99e09c54b
fuzz: always define LLVMFuzzerInitialize() even if we don't need it
Augie Fackler <augie@google.com>
parents:
43614
diff
changeset
|
17 int LLVMFuzzerInitialize(int *argc, char ***argv) |
51a99e09c54b
fuzz: always define LLVMFuzzerInitialize() even if we don't need it
Augie Fackler <augie@google.com>
parents:
43614
diff
changeset
|
18 { |
51a99e09c54b
fuzz: always define LLVMFuzzerInitialize() even if we don't need it
Augie Fackler <augie@google.com>
parents:
43614
diff
changeset
|
19 return 0; |
51a99e09c54b
fuzz: always define LLVMFuzzerInitialize() even if we don't need it
Augie Fackler <augie@google.com>
parents:
43614
diff
changeset
|
20 } |
51a99e09c54b
fuzz: always define LLVMFuzzerInitialize() even if we don't need it
Augie Fackler <augie@google.com>
parents:
43614
diff
changeset
|
21 |
36679 | 22 int hunk_consumer(long a1, long a2, long b1, long b2, void *priv) |
23 { | |
24 // TODO: probably also test returning -1 from this when things break? | |
25 return 0; | |
26 } | |
27 | |
28 int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) | |
29 { | |
41139
2e60a77b7058
xdiff: don't attempt to use fuzzer inputs larger than 100k
Augie Fackler <augie@google.com>
parents:
38173
diff
changeset
|
30 // Don't allow fuzzer inputs larger than 100k, since we'll just bog |
2e60a77b7058
xdiff: don't attempt to use fuzzer inputs larger than 100k
Augie Fackler <augie@google.com>
parents:
38173
diff
changeset
|
31 // down and not accomplish much. |
2e60a77b7058
xdiff: don't attempt to use fuzzer inputs larger than 100k
Augie Fackler <augie@google.com>
parents:
38173
diff
changeset
|
32 if (Size > 100000) { |
2e60a77b7058
xdiff: don't attempt to use fuzzer inputs larger than 100k
Augie Fackler <augie@google.com>
parents:
38173
diff
changeset
|
33 return 0; |
2e60a77b7058
xdiff: don't attempt to use fuzzer inputs larger than 100k
Augie Fackler <augie@google.com>
parents:
38173
diff
changeset
|
34 } |
43614
78df32a8b6f4
fuzz: migrate xdiff fuzzer to use FuzzedDataProvider
Augie Fackler <augie@google.com>
parents:
41139
diff
changeset
|
35 FuzzedDataProvider provider(Data, Size); |
78df32a8b6f4
fuzz: migrate xdiff fuzzer to use FuzzedDataProvider
Augie Fackler <augie@google.com>
parents:
41139
diff
changeset
|
36 std::string left = provider.ConsumeRandomLengthString(Size); |
78df32a8b6f4
fuzz: migrate xdiff fuzzer to use FuzzedDataProvider
Augie Fackler <augie@google.com>
parents:
41139
diff
changeset
|
37 std::string right = provider.ConsumeRemainingBytesAsString(); |
36679 | 38 mmfile_t a, b; |
39 | |
43614
78df32a8b6f4
fuzz: migrate xdiff fuzzer to use FuzzedDataProvider
Augie Fackler <augie@google.com>
parents:
41139
diff
changeset
|
40 a.ptr = (char *)left.c_str(); |
78df32a8b6f4
fuzz: migrate xdiff fuzzer to use FuzzedDataProvider
Augie Fackler <augie@google.com>
parents:
41139
diff
changeset
|
41 a.size = left.size(); |
78df32a8b6f4
fuzz: migrate xdiff fuzzer to use FuzzedDataProvider
Augie Fackler <augie@google.com>
parents:
41139
diff
changeset
|
42 b.ptr = (char *)right.c_str(); |
78df32a8b6f4
fuzz: migrate xdiff fuzzer to use FuzzedDataProvider
Augie Fackler <augie@google.com>
parents:
41139
diff
changeset
|
43 b.size = right.size(); |
36679 | 44 xpparam_t xpp = { |
45 XDF_INDENT_HEURISTIC, /* flags */ | |
46 }; | |
47 xdemitconf_t xecfg = { | |
48 XDL_EMIT_BDIFFHUNK, /* flags */ | |
49 hunk_consumer, /* hunk_consume_func */ | |
50 }; | |
51 xdemitcb_t ecb = { | |
52 NULL, /* priv */ | |
53 }; | |
54 xdl_diff(&a, &b, &xpp, &xecfg, &ecb); | |
55 return 0; // Non-zero return values are reserved for future use. | |
56 } | |
57 | |
58 #ifdef HG_FUZZER_INCLUDE_MAIN | |
59 int main(int argc, char **argv) | |
60 { | |
61 const char data[] = "asdf"; | |
62 return LLVMFuzzerTestOneInput((const uint8_t *)data, 4); | |
63 } | |
64 #endif | |
65 | |
66 } // extern "C" |