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# afl++ drivers

## aflpp_driver

aflpp_driver is used to compile directly libfuzzer `LLVMFuzzerTestOneInput()`
targets.

Just do `afl-clang-fast++ -o fuzz fuzzer_harness.cc libAFLDriver.a [plus required linking]`.

You can also sneakily do this little trick: 
If this is the clang compile command to build for libfuzzer:
  `clang++ -o fuzz -fsanitize=fuzzer fuzzer_harness.cc -lfoo`
then just switch `clang++` with `afl-clang-fast++` and our compiler will
magically insert libAFLDriver.a :)

To use shared-memory testcases, you need nothing to do.
To use stdin testcases give `-` as the only command line parameter.
To use file input testcases give `@@` as the only command line parameter.

IMPORTANT: if you use `afl-cmin` or `afl-cmin.bash` then either pass `-`
or `@@` as command line parameters.

## aflpp_qemu_driver

Note that you can use the driver too for frida_mode (`-O`).

aflpp_qemu_driver is used for libfuzzer `LLVMFuzzerTestOneInput()` targets that
are to be fuzzed in qemu_mode. So we compile them with clang/clang++, without
-fsantize=fuzzer or afl-clang-fast, and link in libAFLQemuDriver.a:

`clang++ -o fuzz fuzzer_harness.cc libAFLQemuDriver.a [plus required linking]`.


Then just do (where the name of the binary is `fuzz`):
```
AFL_QEMU_PERSISTENT_ADDR=0x$(nm fuzz | grep "T LLVMFuzzerTestOneInput" | awk '{print $1}')
AFL_QEMU_PERSISTENT_HOOK=/path/to/aflpp_qemu_driver_hook.so afl-fuzz -Q ... -- ./fuzz`
```

if you use afl-cmin or `afl-showmap -C` with the aflpp_qemu_driver you need to
set the set same AFL_QEMU_... (or AFL_FRIDA_...) environment variables.
If you want to use afl-showmap (without -C) or afl-cmin.bash then you may not
set these environment variables and rather set `AFL_QEMU_DRIVER_NO_HOOK=1`.