[fuzzer] Format README.md

NOTRY=true
R=hablich@chromium.org

Review-Url: https://codereview.chromium.org/2692443002
Cr-Commit-Position: refs/heads/master@{#43138}

test/fuzzer/README.md

 # How to make a libFuzzer fuzzer in V8
 
-This document describes how to make a new libfuzzer fuzzer for V8. A general introduction to libfuzzer can be found at [here](https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/README.md). In short, libFuzzer is an in-process coverage-driven evolutionary fuzzer. libFuzzer serves you with a sequence of byte arrays that you can use to test your code. libFuzzer tries to generate this sequence of byte arrays in a way that maximizes test coverage. 
+This document describes how to make a new libFuzzer fuzzer for V8. A general
+introduction to libFuzzer can be found
+[here](https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/README.md).
+In short, libFuzzer is an in-process coverage-driven evolutionary fuzzer.
+libFuzzer serves you with a sequence of byte arrays that you can use to test
+your code. libFuzzer tries to generate this sequence of byte arrays in a way
+that maximizes test coverage.
 
 **Warning**: By itself libFuzzer typically does not generate valid JavaScript code.
 
 ## Changes to V8
 
-**tldr:** Do the same as https://codereview.chromium.org/2280623002 to introduce a new fuzzer to V8.
-This is a step by step guide on how to make a new fuzzer in V8. In the example the fuzzer is called `foo`.
-1) Copy one of the existing fuzzer implementations in [test/fuzzer/](https://cs.chromium.org/chromium/src/v8/test/fuzzer/), e.g. `cp wasm.cc foo.cc`
-   * Copying an existing fuzzer is a good idea to get all the required setup, e.g. setting up the isolate
-2) Create a directory called `foo` in [test/fuzzer/](https://cs.chromium.org/chromium/src/v8/test/fuzzer/) which contains at least one file
-   * The file is used by the trybots to check whether the fuzzer actually compiles and runs
-3) Copy the build rules of an existing fuzzer in [BUILD.gn](https://cs.chromium.org/chromium/src/v8/BUILD.gn), e.g. the build rules for the [wasm.cc](https://cs.chromium.org/chromium/src/v8/test/fuzzer/wasm.cc) fuzzer are `v8_source_set("wasm_fuzzer")` and `v8_fuzzer("wasm_fuzzer")`. Note that the name has to be the name of the
-directory created in Step 2 + “_fuzzer” so that the scripts on the trybots work
-4) Now you can already compile the fuzzer with `ninja -j 1000 -C out/tmp/v8_simple_foo_fuzzer`
-   * Use this binary to reproduce issues found by cluster fuzz, e.g. `out/tmp/v8_simple_foo_fuzzer testcase.foo` 
-5) Copy the build rules of an existing fuzzer in [test/fuzzer/fuzzer.gyp](https://cs.chromium.org/chromium/src/v8/test/fuzzer/fuzzer.gyp), e.g. the build rules for the [wasm.cc](https://cs.chromium.org/chromium/src/v8/test/fuzzer/wasm.cc) fuzzer are `v8_simple_wasm_fuzzer` and `wasm_fuzzer_lib`
+**tldr:** Do the same as https://codereview.chromium.org/2280623002 to introduce
+a new fuzzer to V8.
+
+This is a step by step guide on how to make a new fuzzer in V8. In the example
+the fuzzer is called `foo`.
+
+1. Copy one of the existing fuzzer implementations in
+   [test/fuzzer/](https://cs.chromium.org/chromium/src/v8/test/fuzzer/), e.g. `cp wasm.cc foo.cc`
+
+   * Copying an existing fuzzer is a good idea to get all the required setup,
+     e.g. setting up the isolate
+
+2. Create a directory called `foo` in
+   [test/fuzzer/](https://cs.chromium.org/chromium/src/v8/test/fuzzer/) which
+   contains at least one file
+
+   * The file is used by the trybots to check whether the fuzzer actually
+     compiles and runs
+
+3. Copy the build rules of an existing fuzzer in
+   [BUILD.gn](https://cs.chromium.org/chromium/src/v8/BUILD.gn), e.g. the build
+   rules for the
+   [wasm.cc](https://cs.chromium.org/chromium/src/v8/test/fuzzer/wasm.cc) fuzzer
+   are `v8_source_set("wasm_fuzzer")` and `v8_fuzzer("wasm_fuzzer")`. Note that
+   the name has to be the name of the directory created in Step 2 + `_fuzzer` so
+   that the scripts on the trybots work
+
+4. Now you can already compile the fuzzer with `ninja -j 1000 -C out/x64.debug/v8_simple_foo_fuzzer`
+
+   * Use this binary to reproduce issues found by cluster fuzz, e.g.
+     `out/tmp/v8_simple_foo_fuzzer testcase.foo`
+
+5. Copy the build rules of an existing fuzzer in
+   [test/fuzzer/fuzzer.gyp](https://cs.chromium.org/chromium/src/v8/test/fuzzer/fuzzer.gyp),
+   e.g. the build rules for the
+   [wasm.cc](https://cs.chromium.org/chromium/src/v8/test/fuzzer/wasm.cc) fuzzer
+   are `v8_simple_wasm_fuzzer` and `wasm_fuzzer_lib`
+
    * This build rule is needed to compile with gyp
-6) Copy the binary name and the test directory name in [test/fuzzer/fuzzer.isolate](https://cs.chromium.org/chromium/src/v8/test/fuzzer/fuzzer.isolate)
-7) Add the fuzzer to the FuzzerTestSuite in [test/fuzzer/testcfg.py](https://cs.chromium.org/chromium/src/v8/test/fuzzer/testcfg.py)
-   * This step is needed to run the fuzzer with the files created in Step 2 on the trybots
-8) Commit the changes described above to the V8 repository
+
+6. Copy the binary name and the test directory name in
+   [test/fuzzer/fuzzer.isolate](https://cs.chromium.org/chromium/src/v8/test/fuzzer/fuzzer.isolate)
+
+7. Add the fuzzer to the FuzzerTestSuite in
+   [test/fuzzer/testcfg.py](https://cs.chromium.org/chromium/src/v8/test/fuzzer/testcfg.py)
+
+   * This step is needed to run the fuzzer with the files created in Step 2 on
+     the trybots
+
+8. Commit the changes described above to the V8 repository
 
 ## Changes to Chromium
-**tldr:** Do the same as https://codereview.chromium.org/2344823002 to add the new fuzzer to cluster fuzz.
-1) Copy the build rules of an existing fuzzer in [testing/libfuzzer/fuzzers/BUILD.gn](https://cs.chromium.org/chromium/src/testing/libfuzzer/fuzzers/BUILD.gn), e.g. the build rule for the [wasm.cc](https://cs.chromium.org/chromium/src/v8/test/fuzzer/wasm.cc) fuzzer is {v8_wasm_fuzzer}. There is no need to set a dictionary , or a seed_corpus. See [chromium-fuzzing-getting-started](https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/getting_started.md) for more information.
-2) Compile the fuzzer in chromium (for different configurations see: https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md):
+
+**tldr:** Do the same as https://codereview.chromium.org/2344823002 to add the
+new fuzzer to cluster fuzz.
+
+1. Copy the build rules of an existing fuzzer in
+   [testing/libfuzzer/fuzzers/BUILD.gn](https://cs.chromium.org/chromium/src/testing/libfuzzer/fuzzers/BUILD.gn),
+   e.g. the build rule for the
+   [wasm.cc](https://cs.chromium.org/chromium/src/v8/test/fuzzer/wasm.cc) fuzzer
+   is `v8_wasm_fuzzer`. There is no need to set a `dictionary` , or a `seed_corpus`.
+   See
+   [chromium-fuzzing-getting-started](https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/getting_started.md)
+   for more information.
+
+2. Compile the fuzzer in chromium (for different configurations see:
+   https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md):
+
    * `gn gen out/libfuzzer '--args=use_libfuzzer=true is_asan=true is_debug=false enable_nacl=false'`
+
    * `ninja -j 1000 -C out/libfuzzer/ v8_foo_fuzzer`
-3) Run the fuzzer locally
+
+3. Run the fuzzer locally
+
    * `mkdir /tmp/empty_corpus && out/libfuzzer/v8_foo_fuzzer /tmp/empty_corpus`