Fix libFuzzer when setting -close_fd_mask to a non-zero value.
In previous implementation, libFuzzer closes the file descriptors for
stdout/stderr. This has some disavantages:
For `fuzzer-fdmask.test`, we write directly to stdout and stderr using the
file streams stdout and stderr, after the file descriptors are closed, which is
undefined behavior. In Windows, in particular, this was making the test fail.
Also, if we close stdout and we open a new file in libFuzzer, we get the file
descriptor 1, which could generate problem if some code assumes file descriptors
refers to stdout and works directly writing to the file descriptor 1, but it
will be writing to the opened file (for example using std::cout).
Instead of closing the file descriptors, I redirect the output to /dev/null on
linux and nul on Windows.
Differential Revision: https://reviews.llvm.org/D28718
llvm-svn: 292743
Reorganize #includes to follow LLVM Coding Standards.
Include some missing headers. Required to use `Printf()`.
Aside from that, this patch contains no functional change.
It is purely a re-organization.
Differential Revision: https://reviews.llvm.org/D27363
llvm-svn: 289560
This patch moves some posix specific file i/o code into a new
file, FuzzerIOPosix.cpp, and provides implementations for these
functions on Windows in FuzzerIOWindows.cpp. This is another
incremental step towards getting libfuzzer working on Windows,
although it still should not be expected to be fully working.
Patch by Marcos Pividori
Differential Revision: https://reviews.llvm.org/D27233
llvm-svn: 288275
In an effort to get libfuzzer working on Windows, we need to make
a distinction between what functions require platform specific
code (e.g. different code on Windows vs Linux) and what code
doesn't. IO functions, for example, tend to be platform
specific.
This patch separates out some of the functions which will need
to have platform specific implementations into different headers,
so that we can then provide different implementations for each
platform.
Aside from that, this patch contains no functional change. It
is purely a re-organization.
Patch by Marcos Pividori
Differential Revision: https://reviews.llvm.org/D27230
llvm-svn: 288264
This fixes linking problems on OSX.
Unfortunately it turns out we need to use an instance of the
``fuzzer::ExternalFunctions`` object in several places so this
commit also replaces all instances with a single global instance.
It also turns out initializing a global ``fuzzer::ExternalFunctions``
before main is entered (i.e. letting the object be initialised by the
global initializers) is not safe (on OSX the call to ``Printf()`` in the
CTOR crashes if it is called from a global initializer) so we instead
have a global ``fuzzer::ExternalFunctions*`` and initialize it inside
``FuzzerDriver()``.
Multiple unit tests depend also depend on the
``fuzzer::ExternalFunctions*`` global so a ``main()`` function has been
added that initializes it before running any tests.
Differential Revision: http://reviews.llvm.org/D20943
llvm-svn: 272072
Summary:
A simple genetic in-process coverage-guided fuzz testing library.
I've used this fuzzer to test clang-format
(it found 12+ bugs, thanks djasper@ for the fixes!)
and it may also help us test other parts of LLVM.
So why not keep it in the LLVM repository?
I plan to add the cmake build rules later (in a separate patch, if that's ok)
and also add a clang-format-fuzzer target.
See README.txt for details.
Test Plan: Tests will follow separately.
Reviewers: djasper, chandlerc, rnk
Reviewed By: rnk
Subscribers: majnemer, ygribov, dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D7184
llvm-svn: 227252
Marcos Pividori