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diff --git a/gcc_plugin/README.instrument_list.md b/gcc_plugin/README.instrument_list.md deleted file mode 100644 index d0eaf6ff..00000000 --- a/gcc_plugin/README.instrument_list.md +++ /dev/null @@ -1,73 +0,0 @@ -======================================== -Using afl++ with partial instrumentation -======================================== - - This file describes how you can selectively instrument only the source files - that are interesting to you using the gcc instrumentation provided by - afl++. - - Plugin by hexcoder-. - - -## 1) Description and purpose - -When building and testing complex programs where only a part of the program is -the fuzzing target, it often helps to only instrument the necessary parts of -the program, leaving the rest uninstrumented. This helps to focus the fuzzer -on the important parts of the program, avoiding undesired noise and -disturbance by uninteresting code being exercised. - -For this purpose, I have added a "partial instrumentation" support to the gcc -plugin of AFLFuzz that allows you to specify on a source file level which files -should be compiled with or without instrumentation. - - -## 2) Building the gcc plugin - -The new code is part of the existing afl++ gcc plugin in the gcc_plugin/ -subdirectory. There is nothing specifically to do :) - - -## 3) How to use the partial instrumentation mode - -In order to build with partial instrumentation, you need to build with -afl-gcc-fast and afl-g++-fast respectively. The only required change is -that you need to set the environment variable AFL_GCC_INSTRUMENT_FILE when calling -the compiler. - -The environment variable must point to a file containing all the filenames -that should be instrumented. For matching, the filename that is being compiled -must end in the filename entry contained in this instrument list (to avoid breaking -the matching when absolute paths are used during compilation). - -For example if your source tree looks like this: - -``` -project/ -project/feature_a/a1.cpp -project/feature_a/a2.cpp -project/feature_b/b1.cpp -project/feature_b/b2.cpp -``` - -and you only want to test feature_a, then create a instrument list file containing: - -``` -feature_a/a1.cpp -feature_a/a2.cpp -``` - -However if the instrument list file contains only this, it works as well: - -``` -a1.cpp -a2.cpp -``` - -but it might lead to files being unwantedly instrumented if the same filename -exists somewhere else in the project directories. - -The created instrument list file is then set to AFL_GCC_INSTRUMENT_FILE when you compile -your program. For each file that didn't match the instrument list, the compiler will -issue a warning at the end stating that no blocks were instrumented. If you -didn't intend to instrument that file, then you can safely ignore that warning. |