pw_fuzzer: Improve .bazelrc fuzzing support

This CL drops the fuzztest.bazelrc generated by FuzzTest, and instead adds imports two new files from //pw_fuzzer: libfuzzer.bazelrc and fuzztest.bazelrc. These facilitate adding fuzzing support to downstream projects' .bazelrc files as well. Additionally, this CL fixes up the Bazel support for FuzzTest. It uses the //pw_toolchain/host_clang:asan_feature and adds a //pw_toolchain/host_clang:fuzztest_feature instead of using FuzzTest's approach of setting {c|link}opts directly. Finally, this CL extands the same support for libFuzzer, in the form of //pw_fuzzer/libfuzzer.bazelrc. Bug: b/347696410 Change-Id: I39ae203574a1065f76a6ca0ac0b1e08242cb380a Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/216112 Reviewed-by: Ted Pudlik <[email protected]> Lint: Lint 🤖 <[email protected]> Commit-Queue: Aaron Green <[email protected]>
google · Sep 13, 2024 · 993b55e · 993b55e
1 parent 82759cc
commit 993b55e
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Showing 12 changed files with 149 additions and 82 deletions.
diff --git a/.bazelrc b/.bazelrc
@@ -100,20 +100,6 @@ common:asan --//pw_toolchain/host_clang:asan
 # accumulate.
 test:asan --test_tag_filters=-integration,-noasan
 
-# Define the --config=asan-libfuzzer configuration.
-build:asan-libfuzzer \
-    --@rules_fuzzing//fuzzing:cc_engine=@rules_fuzzing//fuzzing/engines:libfuzzer
-build:asan-libfuzzer \
-    --@rules_fuzzing//fuzzing:cc_engine_instrumentation=libfuzzer
-build:asan-libfuzzer --@rules_fuzzing//fuzzing:cc_engine_sanitizer=asan
-
-# Include FuzzTest build configurations.
-try-import %workspace%/third_party/fuzztest/fuzztest.bazelrc
-build:fuzztest \
-    --//pw_fuzzer:fuzztest_backend=@com_google_fuzztest//fuzztest:fuzztest_core
-build:fuzztest \
-    --@pigweed//pw_unit_test:main=@com_google_fuzztest//fuzztest:fuzztest_gtest_main
-
 common:ubsan --//pw_toolchain/host_clang:ubsan
 # TODO: https://github.com/bazelbuild/bazel/issues/7322 - We need to repeat the
 # -integration because the test_tag_filters flag does not accumulate.
@@ -124,6 +110,12 @@ common:tsan --//pw_toolchain/host_clang:tsan
 # -integration because the test_tag_filters flag does not accumulate.
 test:tsan --test_tag_filters=-integration,-notsan
 
+# Include libFuzzer build configurations.
+import %workspace%/pw_fuzzer/libfuzzer.bazelrc
+
+# Include FuzzTest build configurations.
+import %workspace%/pw_fuzzer/fuzztest.bazelrc
+
 # Configure workspace status command to test pw_build_info git_build_info
 # https://bazel.build/docs/user-manual#workspace-status-command
 # TODO: b/348046338 - Add a Windows version of this command

diff --git a/pigweed.json b/pigweed.json
@@ -153,6 +153,12 @@
             "--aspects=@rules_rust//rust:defs.bzl%rust_clippy_aspect",
             "--output_groups=clippy_checks",
             "//..."
+          ],
+          [
+            "build",
+            "--config=asan",
+            "--config=fuzztest",
+            "//..."
           ]
         ],
         "integration": [

diff --git a/pw_bluetooth_sapphire/fuchsia/bt_host/BUILD.bazel b/pw_bluetooth_sapphire/fuchsia/bt_host/BUILD.bazel
@@ -54,6 +54,15 @@ cc_library(
         "host.h",
         "util.h",
     ],
+    # `fuchsia_cc_binary` does not understand Pigweed's sanitizer features, e.g.
+    # //pw_toolchain/host_clang:asan_feature. This leads to link errors if the
+    # binary is linked against FuzzTest, as the latter expects the sanitizer to
+    # provide the SanitizerCoverage implementation. Since the binary is not
+    # intended to be a fuzzer, it can just be excluded from fuzzing builds.
+    target_compatible_with = select({
+        "//pw_toolchain/host_clang:fuzztest_enabled": ["@platforms//:incompatible"],
+        "//conditions:default": [],
+    }),
     deps = [
         ":bt_host_config",
         "//pw_async_fuchsia:dispatcher",

diff --git a/pw_fuzzer/fuzztest.bazelrc b/pw_fuzzer/fuzztest.bazelrc
@@ -0,0 +1,32 @@
+# Copyright 2024 The Pigweed 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
+#
+#     https://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.
+
+# Adapted from @com_google_fuzztest//bazel:setup_configs
+
+build:fuzztest --@pigweed//pw_toolchain/host_clang:fuzztest
+build:fuzztest --dynamic_mode=off
+build:fuzztest \
+    --per_file_copt=+//,-fuzztest/.*,-googletest/.*,-googlemock/.*@-fsanitize-coverage=inline-8bit-counters,-fsanitize-coverage=trace-cmp
+build:fuzztest \
+    --@pigweed//pw_fuzzer:fuzztest_backend=@com_google_fuzztest//fuzztest:fuzztest_core
+build:fuzztest \
+    --@pigweed//pw_unit_test:backend=@pigweed//pw_unit_test:googletest
+build:fuzztest \
+    --@pigweed//pw_unit_test:main=@com_google_fuzztest//fuzztest:fuzztest_gtest_main
+
+# For fuzzing, we want to disregard any test strategy options and execute each
+# test locally and one at a time. We also want to display as much information as
+# soon as it is available, including PRNG seeds and corpus statistics.
+# Both of these are achieved by streaming the test output.
+test:fuzztest --test_output=streamed
diff --git a/pw_fuzzer/guides/fuzztest.rst b/pw_fuzzer/guides/fuzztest.rst
@@ -80,14 +80,30 @@ See the following:
    .. tab-item:: Bazel
       :sync: bazel
 
-      FuzzTest provides a build configuration that can be imported into your
-      ``.bazelrc`` file. Add the following:
+      Include Abseil-C++ and GoogleTest in your ``WORKSPACE`` file. For example:
+
+      .. code-block::
+
+         http_archive(
+            name = "com_google_absl",
+            sha256 = "338420448b140f0dfd1a1ea3c3ce71b3bc172071f24f4d9a57d59b45037da440",
+            strip_prefix = "abseil-cpp-20240116.0",
+            url = "https://github.com/abseil/abseil-cpp/releases/download/20240116.0/abseil-cpp-20240116.0.tar.gz",
+         )
+
+         git_repository(
+            name = "com_google_googletest",
+            commit = "3b6d48e8d5c1d9b3f9f10ac030a94008bfaf032b",
+            remote = "https://pigweed.googlesource.com/third_party/github/google/googletest",
+         )
+
+      Then, import the FuzzTest build configurations in your ``.bazelrc`` file
+      by adding and adapting the following:
 
       .. code-block::
 
          # Include FuzzTest build configurations.
-         try-import %workspace%/third_party/fuzztest/fuzztest.bazelrc
-         build:fuzztest --@pigweed//targets:fuzztest_config=//pw_fuzzer:fuzztest
+         try-import %workspace%/path/to/pigweed/pw_fuzzer/fuzztest.bazelrc
 
 ----------------------------------------
 Step 1: Write a unit test for the target

diff --git a/pw_fuzzer/guides/libfuzzer.rst b/pw_fuzzer/guides/libfuzzer.rst
@@ -52,19 +52,10 @@ installation. In order to use it, you only need to define a suitable toolchain.
    .. tab-item:: Bazel
       :sync: bazel
 
-      Include ``rules_fuzzing`` and its Abseil C++ dependency in your
-      ``WORKSPACE`` file. For example:
+      Include ``rules_fuzzing`` in your ``WORKSPACE`` file. For example:
 
       .. code-block::
 
-         # Required by: rules_fuzzing.
-         http_archive(
-             name = "com_google_absl",
-             sha256 = "3ea49a7d97421b88a8c48a0de16c16048e17725c7ec0f1d3ea2683a2a75adc21",
-             strip_prefix = "abseil-cpp-20230125.0",
-             urls = ["https://github.com/abseil/abseil-cpp/archive/refs/tags/20230125.0.tar.gz"],
-         )
-
          # Set up rules for fuzz testing.
          http_archive(
              name = "rules_fuzzing",
@@ -81,15 +72,13 @@ installation. In order to use it, you only need to define a suitable toolchain.
 
          rules_fuzzing_init()
 
-      Then, define the following build configuration in your ``.bazelrc`` file:
+      Then, import the libFuzzer build configurations in your ``.bazelrc`` file
+      by adding and adapting the following:
 
       .. code-block::
 
-         build:asan-libfuzzer \
-             --@rules_fuzzing//fuzzing:cc_engine=@rules_fuzzing//fuzzing/engines:libfuzzer
-         build:asan-libfuzzer \
-             --@rules_fuzzing//fuzzing:cc_engine_instrumentation=libfuzzer
-         build:asan-libfuzzer --@rules_fuzzing//fuzzing:cc_engine_sanitizer=asan
+         # Include FuzzTest build configurations.
+         try-import %workspace%/path/to/pigweed/pw_fuzzer/libfuzzer.bazelrc
 
 ------------------------------------
 Step 1: Write a fuzz target function

diff --git a/pw_fuzzer/libfuzzer.bazelrc b/pw_fuzzer/libfuzzer.bazelrc
@@ -0,0 +1,25 @@
+# Copyright 2024 The Pigweed 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
+#
+#     https://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.
+
+# TODO(b/347696410): Currently, building with `--config=libfuzzer` causes link
+# errors for `pw_target_runner`.
+
+build:libfuzzer \
+    --@rules_fuzzing//fuzzing:cc_engine=@rules_fuzzing//fuzzing/engines:libfuzzer
+build:libfuzzer \
+    --@rules_fuzzing//fuzzing:cc_engine_instrumentation=libfuzzer
+build:libfuzzer --@rules_fuzzing//fuzzing:cc_engine_sanitizer=asan
+
+test:libfuzzer --test_output=streamed
+
diff --git a/pw_system/BUILD.bazel b/pw_system/BUILD.bazel
@@ -542,6 +542,11 @@ pw_cc_binary(
     # testonly dependencies.
     testonly = True,
     srcs = ["example_user_app_init.cc"],
+    # TODO(b/365184562): This target does not build with asan and fuzztest.
+    target_compatible_with = select({
+        "//pw_fuzzer:use_fuzztest": ["@platforms//:incompatible"],
+        "//conditions:default": [],
+    }),
     deps = [
         ":pw_system",
         "//pw_unit_test:rpc_service",

diff --git a/pw_toolchain/host_clang/BUILD.bazel b/pw_toolchain/host_clang/BUILD.bazel
@@ -219,6 +219,28 @@ pw_cc_feature_set(
     all_of = [":rules_rust_unsupported_feature"],
 )
 
+bool_flag(
+    name = "fuzztest",
+    build_setting_default = False,
+)
+
+config_setting(
+    name = "fuzztest_enabled",
+    flag_values = {
+        ":fuzztest": "true",
+    },
+)
+
+pw_cc_feature(
+    name = "fuzztest_feature",
+    enabled = select({
+        ":fuzztest_enabled": True,
+        "//conditions:default": False,
+    }),
+    feature_name = "fuzztest",
+    flag_sets = ["@pw_toolchain//flag_sets:fuzztest"],
+)
+
 # This is a sentinel feature defined by rules_rust. It is by definition
 # unsupported: rules_rust will disable this feature when linking Rust code.
 pw_cc_feature(

diff --git a/pw_toolchain_bazel/flag_sets/BUILD.bazel b/pw_toolchain_bazel/flag_sets/BUILD.bazel
@@ -156,3 +156,17 @@ pw_cc_flag_set(
         "-DTHREAD_SANITIZER",
     ],
 )
+
+pw_cc_flag_set(
+    name = "fuzztest",
+    actions = [
+        "@pw_toolchain//actions:all_compiler_actions",
+        "@pw_toolchain//actions:all_link_actions",
+    ],
+    flags = [
+        "-mcrc32",
+        "-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION",
+        "-UNDEBUG",
+        "-D_LIBCPP_ENABLE_ASSERTIONS=1",
+    ],
+)
diff --git a/targets/rp2040/BUILD.bazel b/targets/rp2040/BUILD.bazel
@@ -189,6 +189,11 @@ pw_cc_binary(
     name = "system_async_example",
     testonly = True,
     srcs = ["system_async_example.cc"],
+    # TODO(b/365184562): This target does not build with asan and fuzztest.
+    target_compatible_with = select({
+        "//pw_fuzzer:use_fuzztest": ["@platforms//:incompatible"],
+        "//conditions:default": [],
+    }),
     deps = [
         "//pw_channel:rp2_stdio_channel",
         "//pw_libcxx",

diff --git a/third_party/fuzztest/fuzztest.bazelrc b/third_party/fuzztest/fuzztest.bazelrc