llvm/lib/Fuzzer/FuzzerMain.cpp
Dan Liew 8bb56ccbc0 [LibFuzzer] Reimplement how the optional user functions are called.
The motivation for this change is to fix linking issues on OSX.
However this only partially fixes linking issues (the uninstrumented
tests and a few others  won't succesfully link yet).

This change introduces a struct of function pointers
(``fuzzer::ExternalFuntions``) which when initialised will point to the
optional functions if they are available.  Currently these
``LLVMFuzzerInitialize`` and ``LLVMFuzzerCustomMutator`` functions.

Two implementations of ``fuzzer::ExternalFunctions`` constructor are
provided one for Linux and one for OSX.

The OSX implementation uses ``dlsym()`` because the prior implementation
using weak symbols does not work unless the additional flags are passed
to the linker.

The Linux implementation continues to use weak symbols because the
``dlsym()`` approach does not work unless additional flags are passed
to the linker.

Differential Revision: http://reviews.llvm.org/D20741

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271491 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-02 05:48:02 +00:00

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//===- FuzzerMain.cpp - main() function and flags -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// main() and flags.
//===----------------------------------------------------------------------===//
#include "FuzzerInterface.h"
#include "FuzzerInternal.h"
extern "C" {
// This function should be defined by the user.
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);
} // extern "C"
int main(int argc, char **argv) {
return fuzzer::FuzzerDriver(&argc, &argv, LLVMFuzzerTestOneInput);
}