skia2/fuzz/FuzzScaleToSides.cpp
Kevin Lubick 416b248312 Avoid platform-dependent function params in Fuzzer
We use this approach instead of T next() because different compilers
evaluate function parameters in different orders. If fuzz->next()
returned 5 and then 7, foo(fuzz->next(), fuzz->next()) would be
foo(5, 7) when compiled on GCC and foo(7, 5) when compiled on Clang.
By requiring params to be passed in, we avoid the temptation to call 
next() in a way that does not consume fuzzed bytes in a single 
platform-independent order.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4392

Change-Id: I35de849f82e8be45378f662a48100eb732fa8895
Reviewed-on: https://skia-review.googlesource.com/4392
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2016-11-10 22:52:03 +00:00

44 lines
1.1 KiB
C++

/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
// Reminder of how to run:
// $ env CC=afl-clang CXX=afl-clang++ ./gyp_skia
// $ ninja -C out/Debug fuzz
// $ afl-fuzz -i fuzz-in -o fuzz-out out/Debug/fuzz -n ScaleToSides -b @@
// where you seed fuzz-in/ with one or more small files.
#include "Fuzz.h"
#include "SkScaleToSides.h"
#include <cmath>
DEF_FUZZ(ScaleToSides, fuzz) {
float radius1, radius2, width;
fuzz->next(&radius1, &radius2, &width);
if (!std::isfinite(radius1) ||
!std::isfinite(radius2) ||
!std::isfinite(width) ||
radius1 <= 0.0f ||
radius2 <= 0.0f ||
width <= 0.0f)
{
return;
}
double scale = (double)width / ((double)radius1 + (double)radius2);
if (scale >= 1.0 || scale <= 0.0) {
return;
}
SkDebugf("%g %g %g %g\n", radius1, radius2, width, scale);
SkScaleToSides::AdjustRadii(width, scale, &radius1, &radius2);
// TODO(mtklein): add fuzz->keepResult()
volatile float junk = 0.0f;
junk *= radius1;
junk *= radius2;
}