Mercurial > public > mercurial-scm > hg
diff contrib/fuzz/xdiff.cc @ 38173:fa0ddd5e8fff
fuzz: extract some common utilities and use modern C++ idioms
Alex Gaynor suggested we should probably copy the left and right sides
of diffs to new blocks so we can detect over-reads in the diffing
code, and I agree. Once I got into that, I realized we should do
things with C++17 idioms rather than keep using malloc() and
free(). This change is the result. I tried to split it more than this
and failed.
Everything still compiles and works in the oss-fuzz container, so I
think we can count on C++17 being available!
Differential Revision: https://phab.mercurial-scm.org/D3675
| author | Augie Fackler <augie@google.com> |
|---|---|
| date | Sat, 28 Apr 2018 22:18:50 -0400 |
| parents | 04d64163039a |
| children | 2e60a77b7058 |
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--- a/contrib/fuzz/xdiff.cc Sat Apr 28 22:13:33 2018 -0400 +++ b/contrib/fuzz/xdiff.cc Sat Apr 28 22:18:50 2018 -0400 @@ -10,6 +10,8 @@ #include <inttypes.h> #include <stdlib.h> +#include "fuzzutil.h" + extern "C" { int hunk_consumer(long a1, long a2, long b1, long b2, void *priv) @@ -20,21 +22,17 @@ int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { - if (!Size) { + auto maybe_inputs = SplitInputs(Data, Size); + if (!maybe_inputs) { return 0; } - // figure out a random point in [0, Size] to split our input. - size_t split = Data[0] / 255.0 * Size; - + auto inputs = std::move(maybe_inputs.value()); 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; + a.ptr = inputs.left.get(); + a.size = inputs.left_size; + b.ptr = inputs.right.get(); + b.size = inputs.right_size; xpparam_t xpp = { XDF_INDENT_HEURISTIC, /* flags */ };