[CIFuzz] Add support for different sanitizers (#3969)

* Revert "Revert "[CIFuzz] Add support for different sanitizers (#3516)""

This reverts commit c580d0d626247017dede2847869e1eb8a3705ee1.

* cifuzz: pass "sanitizer" to the "run fuzzer" step

It's a follow-up to https://github.com/google/oss-fuzz/pull/3516 that
should fix https://github.com/google/oss-fuzz/issues/3727.

* [cifuzz] drop a $

That's another follow-up to #3516 that should help to pass sanitizer correctly.
Otherwise, it always falls back to address with:

2020-06-11 21:10:14,852 - root - INFO - $address is not a project sanitizer, defaulting to address.

1 files changed, 62 insertions, 0 deletions

diff --git a/docs/getting-started/continuous_integration.md b/docs/getting-started/continuous_integration.md
index cc461a5b4..d536ea9be 100644
--- a/docs/getting-started/continuous_integration.md
+++ b/docs/getting-started/continuous_integration.md
@@ -82,6 +82,7 @@ jobs:
 
 ### Optional configuration
 
+#### Configurable Variables
 `fuzz-time`: Determines how long CIFuzz spends fuzzing your project in seconds.
 The default is 600 seconds. The GitHub Actions max run time is 21600 seconds (6 hours).
 
@@ -94,6 +95,67 @@ make sure to set the dry-run parameters in both the `Build Fuzzers` and `Run Fuz
 limit for broken fuzz targets than OSS-Fuzz's check_build. Most users should
 not set this.
 
+#### Adding Other Sanitizers
+CIFuzz supports address, memory and undefined sanitizers. Address is the default
+sanitizer and will be used for every job in which a sanitizer is not specified.
+To add another sanitizer to your workflow copy the `Fuzzing` job and rename it
+to the sanitizer you want to fuzz with. Then add the sanitizer variable to both
+the `Build Fuzzers` step and the `Run Fuzzers` step. The choices are `'address'`,
+`'memory'`, and `'undefined'`. Once this additional job is configured the CIFuzz
+workflow will run all of the jobs corresponding to each sanitizer simultaneously.
+It is important to note that the `Build Fuzzers` and the `Run Fuzzers` sanitizer
+field needs to be the same. See the following main.yml file for an example.
+
+```yaml
+name: CIFuzz
+on: [pull_request]
+jobs:
+ AddressFuzzing:
+   runs-on: ubuntu-latest
+   steps:
+   - name: Build Fuzzers
+     uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master
+     with:
+       oss-fuzz-project-name: 'example'
+       dry-run: false
+       # sanitizer: address
+   - name: Run Fuzzers
+     uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
+     with:
+       oss-fuzz-project-name: 'example'
+       fuzz-seconds: 600
+       dry-run: false
+       # sanitizer: address
+   - name: Upload Crash
+     uses: actions/upload-artifact@v1
+     if: failure()
+     with:
+       name: Address-Artifacts
+       path: ./out/artifacts
+ UndefinedFuzzing:
+   runs-on: ubuntu-latest
+   steps:
+   - name: Build Fuzzers
+     uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master
+     with:
+       oss-fuzz-project-name: 'example'
+       dry-run: false
+       sanitizer: 'undefined'
+   - name: Run Fuzzers
+     uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
+     with:
+       oss-fuzz-project-name: 'example'
+       fuzz-seconds: 600
+       dry-run: false
+       sanitizer: 'undefined'
+   - name: Upload Crash
+     uses: actions/upload-artifact@v1
+     if: failure()
+     with:
+       name: Undefined-Artifacts
+       path: ./out/artifacts
+```
+
 ## Understanding results
 
 The results of CIFuzz can be found in two different places.