Integration of pw_fuzzer using FuzzTest (#34274)

* latest trial to build pw_fuzz

* migrating FuzzPayloadDecoder FuzzTest

* fix error related to latomic

* adding template for pw_fuzz_tests

* fix for linux_sysroot issue

* adding FuzzTests

* fixing warning issue

* adding support to build pw-fuzztests with build_examples.py

* Restyled by whitespace

* Restyled by clang-format

* adding pw_fuzz_tests to default target

* fixing build_examples test golden standard

* Adding Fuzzing Targets

* Adding Documentation

* cleaning-up tests

* spelling mistakes

* integrating comments

---------

Co-authored-by: Restyled.io <commits@restyled.io>

.github/.wordlist.txt

@@ -37,6 +37,7 @@ AdvSendAdvert
 AE
 aef
 AES
+AFL
 AIDL
 algs
 alloc
@@ -570,6 +571,7 @@ fsync
 ftd
 fullclean
 fuzzer
+fuzztest
 FW
 gbl
 gcloud
@@ -1008,6 +1010,7 @@ optionOverride
 optionsMask
 optionsOverride
 orgs
+OSS
 OTA
 OTADownloader
 otaDownloadPath

.gitmodules

@@ -329,3 +329,19 @@
 	path = third_party/infineon/psoc6/psoc6_sdk/libs/lwip-network-interface-integration
 	url = https://github.com/Infineon/lwip-network-interface-integration.git
 	platforms = infineon
+[submodule "third_party/abseil-cpp/src"]
+	path = third_party/abseil-cpp/src
+	url = https://github.com/abseil/abseil-cpp.git
+	platforms = linux,darwin
+[submodule "third_party/fuzztest"]
+	path = third_party/fuzztest
+	url = https://github.com/google/fuzztest.git
+	platforms = linux,darwin
+[submodule "third_party/googletest"]
+	path = third_party/googletest
+	url = https://github.com/google/googletest
+	platforms = linux,darwin
+[submodule "third_party/re2/src"]
+	path = third_party/re2/src
+	url = https://github.com/google/re2.git
+	platforms = linux,darwin

BUILD.gn

@@ -62,6 +62,18 @@ if (current_toolchain != "${dir_pw_toolchain}/default:default") {
     }
   }
 
+  if (pw_enable_fuzz_test_targets) {
+    group("pw_fuzz_tests") {
+      deps = [
+        "${chip_root}/src/credentials/tests:fuzz-chip-cert-pw(//build/toolchain/pw_fuzzer:chip_pw_fuzztest)",
+        "${chip_root}/src/lib/core/tests:fuzz-tlv-reader-pw(//build/toolchain/pw_fuzzer:chip_pw_fuzztest)",
+        "${chip_root}/src/lib/dnssd/minimal_mdns/tests:fuzz-minmdns-packet-parsing-pw(//build/toolchain/pw_fuzzer:chip_pw_fuzztest)",
+        "${chip_root}/src/lib/format/tests:fuzz-payload-decoder-pw(//build/toolchain/pw_fuzzer:chip_pw_fuzztest)",
+        "${chip_root}/src/setup_payload/tests:fuzz-setup-payload-base38-pw(//build/toolchain/pw_fuzzer:chip_pw_fuzztest)",
+      ]
+    }
+  }
+
   # Matter's in-tree pw_python_package or pw_python_distribution targets.
   _matter_python_packages = [
     "//examples/chef",
@@ -140,6 +152,10 @@ if (current_toolchain != "${dir_pw_toolchain}/default:default") {
       deps += [ "//:fuzz_tests" ]
     }
 
+    if (pw_enable_fuzz_test_targets) {
+      deps += [ "//:pw_fuzz_tests" ]
+    }
+
     if (chip_device_platform != "none") {
       deps += [ "${chip_root}/src/app/server" ]
     }

build/chip/fuzz_test.gni

@@ -14,12 +14,17 @@
 
 import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
+import("//build_overrides/pigweed.gni")
+
 import("${build_root}/config/compiler/compiler.gni")
 import("${chip_root}/build/chip/tests.gni")
+import("${dir_pw_unit_test}/test.gni")
 
 declare_args() {
   enable_fuzz_test_targets = is_clang && chip_build_tests &&
                              (current_os == "linux" || current_os == "mac")
+
+  pw_enable_fuzz_test_targets = false
 }
 
 # Define a fuzz target for chip.
@@ -66,3 +71,57 @@ template("chip_fuzz_target") {
     }
   }
 }
+
+# Define a fuzz target for Matter using pw_fuzzer and Google FuzzTest Framework.
+#
+# Google FuzzTest is only supported on Linux and MacOS using Clang:
+#
+# Sample usage
+#
+# chip_pw_fuzz_target("fuzz-target-name") {
+#   test_source = [
+#      "FuzzTarget.cpp", # Fuzz target
+#   ]
+#
+#   public_deps = [
+#     "${chip_root}/src/lib/foo",         # add dependencies here
+#   ]
+# }
+#
+#
+template("chip_pw_fuzz_target") {
+  if (defined(invoker.test_source)) {
+    _test_output_dir = "${root_out_dir}/tests"
+
+    if (defined(invoker.output_dir)) {
+      _test_output_dir = invoker.output_dir
+    }
+
+    pw_test(target_name) {
+      forward_variables_from(invoker,
+                             [
+                               "deps",
+                               "public_deps",
+                               "cflags",
+                               "configs",
+                               "remove_configs",
+                             ])
+
+      # TODO: remove this after pw_fuzzer's integration with OSS-Fuzz is complete.
+      #just a test for running FuzzTest with libfuzzer-compatibility mode, since this is the mode supported by OSS-fuzz
+      # defines = [
+      # "FUZZTEST_COMPATIBILITY_MODE=libfuzzer",
+      #   "MAKE_BUILD_TYPE=RelWithDebug",
+      #  ]
+
+      sources = invoker.test_source
+      output_dir = _test_output_dir
+
+      deps = [ "$dir_pw_fuzzer:fuzztest" ]
+
+      # this is necessary so FuzzTest is compiled into an executable in third_party/pigweed/repo/pw_unit_test/test.gni
+      # otherwise it will be built successfully but with FuzzTarget.DISABLED.ninja and no executable.
+      enable_if = true
+    }
+  }
+}

build/toolchain/pw_fuzzer/BUILD.gn

@@ -0,0 +1,70 @@
+# Copyright (c) 2024 Project CHIP Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import("//build_overrides/build.gni")
+import("//build_overrides/pigweed.gni")
+
+import("$dir_pigweed/targets/host/target_toolchains.gni")
+import("${build_root}/toolchain/gcc_toolchain.gni")
+
+# creating a secondary toolchain to be used with pw_fuzzer FuzzTests
+# This toolchain is downstreamed from pigweed's pw_target_toolchain_host.clang_fuzz
+# it allows us to specifically use googletest for fuzzing (instead of the lighter version of googletest used for unit testing)
+
+gcc_toolchain("chip_pw_fuzztest") {
+  forward_variables_from(pw_target_toolchain_host.clang_fuzz, "*", [ "name" ])
+
+  toolchain_args = {
+    # This is needed to have the defaults passed from pw_target_toolchain_host.clang_fuzz to the current scope
+    forward_variables_from(defaults, "*")
+
+    pw_unit_test_MAIN = "$dir_pw_fuzzer:fuzztest_main"
+    pw_unit_test_BACKEND = "$dir_pw_fuzzer:gtest"
+
+    # The next three lines are needed by the gcc_toolchain template
+    current_os = host_os
+    current_cpu = host_cpu
+    is_clang = true
+
+    # the upstream pigweed host_clang toolchain defines a default sysroot, which results in build errors
+    # since it does not include SSL lib and is supposed to be minimal by design.
+    # by removing this default config, we will use the system's libs. Otherwise we can define our own sysroot.
+    # discussion on: https://discord.com/channels/691686718377558037/1275092695764959232
+    remove_default_configs = [ "$dir_pw_toolchain/host_clang:linux_sysroot" ]
+
+    # when is_debug = true, we pass -O0 to cflags and ldflags, while upstream pw_fuzzer toolchain defines "optimize_speed" config that passes -O2.
+    # This condition was added to prevent mixing the flags
+    if (is_debug) {
+      remove_default_configs += [ "$dir_pw_build:optimize_speed" ]
+    }
+
+    # removing pigweed downstreamed configs related to warnings
+    # These are triggering an error related to -Wcast-qual in third_party/nlio
+    remove_default_configs += [
+      "$dir_pw_build:strict_warnings",
+      "$dir_pw_build:extra_strict_warnings",
+    ]
+
+    # the third_party abseil-cpp triggers warnings related to [-Wformat-nonliteral]
+    treat_warnings_as_errors = false
+
+    dir_pw_third_party_abseil_cpp = "//third_party/abseil-cpp/src"
+    dir_pw_third_party_fuzztest = "//third_party/fuzztest"
+    dir_pw_third_party_googletest = "//third_party/googletest"
+
+    # TODO: Seems that re2 support within FuzzTest was deprecated, keeping it defined is triggering warning
+    # Remove if re2 is indeed not needed
+    # dir_pw_third_party_re2 = "//third_party/re2/src"
+  }
+}

docs/guides/BUILDING.md

@@ -382,6 +382,26 @@ They pick up environment variables such as `$CFLAGS`, `$CXXFLAGS` and
 
 You likely want `libfuzzer` + `asan` builds instead for local testing.
 
+### `pw_fuzzer` `FuzzTests`
+
+An Alternative way for writing and running Fuzz Tests is Google's `FuzzTest`
+framework, integrated through `pw_fuzzer`. The Tests will have to be built and
+executed manually.
+
+```
+./scripts/build/build_examples.py --target linux-x64-tests-clang-pw-fuzztest build
+```
+
+NOTE: `asan` is enabled by default in FuzzTest, so please do not add it in
+build_examples.py invocation.
+
+Tests will be located in:
+`out/linux-x64-tests-clang-pw-fuzztest/chip_pw_fuzztest/tests/` where
+`chip_pw_fuzztest` is the name of the toolchain used.
+
+-   Details on How To Run Fuzz Tests in
+    [Running FuzzTests](https://github.com/project-chip/connectedhomeip/blob/master/docs/testing/fuzz_testing.md)
+
 ## Build custom configuration
 
 The build is configured by setting build arguments. These you can set in one of