# Important changes in AFL++

This document lists important changes in AFL++, for example, major behavior changes.

## From version 3.00 onwards

With AFL++ 3.13-3.20 we introduce frida_mode (-O) to have an alternative for
binary-only fuzzing. It is slower than Qemu mode but works on MacOS, Android,
iOS etc.

With AFL++ 3.15 we introduced the following changes from previous behaviors:
  * Also -M main mode does not do deterministic fuzzing by default anymore
  * afl-cmin and afl-showmap -Ci now descent into subdirectories like
    afl-fuzz -i does (but note that afl-cmin.bash does not)

With AFL++ 3.14 we introduced the following changes from previous behaviors:
  * afl-fuzz: deterministic fuzzing it not a default for -M main anymore
  * afl-cmin/afl-showmap -i now descends into subdirectories (afl-cmin.bash,
    however, does not)

With AFL++ 3.10 we introduced the following changes from previous behaviors:
  * The '+' feature of the '-t' option now means to  auto-calculate the timeout
    with the value given being the maximum timeout. The original meaning of
    "skipping timeouts instead of abort" is now inherent to the -t option.

With AFL++ 3.00 we introduced changes that break some previous AFL and AFL++
behaviors and defaults:
  * There are no llvm_mode and gcc_plugin subdirectories anymore and there is
    only one compiler: afl-cc. All previous compilers now symlink to this one.
    All instrumentation source code is now in the `instrumentation/` folder.
  * The gcc_plugin was replaced with a new version submitted by AdaCore that
    supports more features. Thank you!
  * qemu_mode got upgraded to QEMU 5.1, but to be able to build this a current
    ninja build tool version and python3 setuptools are required.
    qemu_mode also got new options like snapshotting, instrumenting specific
    shared libraries, etc. Additionally QEMU 5.1 supports more CPU targets so
    this is really worth it.
  * When instrumenting targets, afl-cc will not supersede optimizations anymore
    if any were given. This allows to fuzz targets build regularly like those
    for debug or release versions.
  * afl-fuzz:
    * if neither -M or -S is specified, `-S default` is assumed, so more
      fuzzers can easily be added later
    * `-i` input directory option now descends into subdirectories. It also
      does not fatal on crashes and too large files, instead it skips them
      and uses them for splicing mutations
    * -m none is now default, set memory limits (in MB) with e.g. -m 250
    * deterministic fuzzing is now disabled by default (unless using -M) and
      can be enabled with -D
    * a caching of test cases can now be performed and can be modified by
      editing config.h for TESTCASE_CACHE or by specifying the environment
      variable `AFL_TESTCACHE_SIZE` (in MB). Good values are between 50-500
      (default: 50).
    * -M mains do not perform trimming
  * examples/ got renamed to utils/
  * libtokencap/ libdislocator/ and qdbi_mode/ were moved to utils/
  * afl-cmin/afl-cmin.bash now search first in PATH and last in AFL_PATH