From 048fa5a8f18d222d51f928da4098c2c826b88d62 Mon Sep 17 00:00:00 2001
From: Xinhao Yuan <xinhaoyuan@google.com>
Date: Fri, 10 Jan 2025 12:09:33 -0800
Subject: [PATCH] Enable FuzzTest on macOS (experimental) with documentation.

PiperOrigin-RevId: 714132065
---
 doc/quickstart-bazel.md                         |  7 ++++++-
 .../fuzz_tests_for_functional_testing.cc        |  2 +-
 fuzztest/internal/coverage.cc                   | 17 ++++++++++++-----
 fuzztest/internal/runtime.cc                    |  6 +++---
 4 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/doc/quickstart-bazel.md b/doc/quickstart-bazel.md
index 7f73f8ae..0977ba21 100644
--- a/doc/quickstart-bazel.md
+++ b/doc/quickstart-bazel.md
@@ -10,7 +10,7 @@ more extensive showcase of the FuzzTest framework, consider doing the
 
 To use FuzzTest, you'll need:
 
-*   A Linux-based operating system
+*   A Linux-based operating system or macOS (experimental)
 *   [Clang](https://clang.llvm.org/)
 *   [Bazel](https://bazel.build/)
 
@@ -52,6 +52,8 @@ Next, create a [Bazel configuration file](https://bazel.build/run/bazelrc) named
 `.bazelrc` to configure the build flags:
 
 ```
+common --enable_platform_specific_config
+
 # Force the use of Clang for all builds. FuzzTest relies on Clang for sanitizer
 # coverage (https://clang.llvm.org/docs/SanitizerCoverage.html).
 build --action_env=CC=clang
@@ -63,6 +65,9 @@ build --cxxopt=-std=c++17
 # Show everything when running tests.
 test --test_output=streamed
 
+build:macos --macos_minimum_os=10.15
+build:macos --no@fuzztest//fuzztest:use_riegeli
+
 # To create this file, please run:
 #
 #  bazel run @fuzztest//bazel:setup_configs > fuzztest.bazelrc
diff --git a/e2e_tests/testdata/fuzz_tests_for_functional_testing.cc b/e2e_tests/testdata/fuzz_tests_for_functional_testing.cc
index eeec09ae..fc88e680 100644
--- a/e2e_tests/testdata/fuzz_tests_for_functional_testing.cc
+++ b/e2e_tests/testdata/fuzz_tests_for_functional_testing.cc
@@ -552,7 +552,7 @@ FUZZ_TEST(MySuite, FailsWhenOneofFieldDoesntHaveOneofValue)
     .WithDomains(Arbitrary<TestProtobuf>()
                      .WithOneofAlwaysSet("oneof_field")
                      .WithFieldUnset("oneof_u32")
-                     .WithInt64Field("oneof_i64", fuzztest::Just(1l)));
+                     .WithInt64Field("oneof_i64", fuzztest::Just(int64_t{1})));
 
 void FailsIfProtobufEnumEqualsLabel4(TestProtobuf::Enum e) {
   if (e == TestProtobuf::Enum::TestProtobuf_Enum_Label4) {
diff --git a/fuzztest/internal/coverage.cc b/fuzztest/internal/coverage.cc
index 25a6623f..d4d50d18 100644
--- a/fuzztest/internal/coverage.cc
+++ b/fuzztest/internal/coverage.cc
@@ -172,9 +172,16 @@ void ExecutionCoverage::UpdateMaxStack(uintptr_t PC) {
   }
 }
 
-// Coverage only available in Clang, but only for Linux.
-// iOS and Windows and Android might not have what we need.
-#if defined(__clang__) && defined(__linux__) && !defined(__ANDROID__)
+// Coverage only available in Clang, but only for Linux and macOS.
+// Windows and Android might not have what we need.
+#if /* Supported compilers */  \
+    defined(__clang__) &&      \
+    (/* Supported platforms */ \
+     (defined(__linux__) && !defined(__ANDROID__)) || defined(__APPLE__))
+#define FUZZTEST_COVERAGE_IS_AVAILABLE
+#endif
+
+#ifdef FUZZTEST_COVERAGE_IS_AVAILABLE
 namespace {
 // Use clang's vector extensions. This way it will implement with whatever the
 // platform supports.
@@ -315,7 +322,7 @@ bool CorpusCoverage::Update(ExecutionCoverage* execution_coverage) {
   return new_coverage || execution_coverage->NewCoverageFound();
 }
 
-#else  // __clang__ && __linux__
+#else  // FUZZTEST_COVERAGE_IS_AVAILABLE
 
 // On other compilers we just need it to build, but we know we don't have any
 // instrumentation.
@@ -326,7 +333,7 @@ bool CorpusCoverage::Update(ExecutionCoverage* execution_coverage) {
   return false;
 }
 
-#endif  // __clang__ && __linux__
+#endif  // FUZZTEST_COVERAGE_IS_AVAILABLE
 
 }  // namespace fuzztest::internal
 
diff --git a/fuzztest/internal/runtime.cc b/fuzztest/internal/runtime.cc
index ecdf0200..a19be1a9 100644
--- a/fuzztest/internal/runtime.cc
+++ b/fuzztest/internal/runtime.cc
@@ -403,7 +403,7 @@ void Runtime::OnTestIterationEnd() {
   watchdog_spinlock_.clear();
 }
 
-#if defined(__linux__)
+#if defined(__linux__) || defined(__APPLE__)
 
 struct OldSignalHandler {
   int signum;
@@ -554,14 +554,14 @@ void Runtime::PrintReportOnDefaultSink() const {
   PrintReport(&signal_out_sink);
 }
 
-#else   // __linux__
+#else   // __linux__ || __APPLE__
 // TODO(sbenzaquen): We should still install signal handlers in other systems.
 void InstallSignalHandlers(FILE* out) {}
 
 void Runtime::PrintFinalStatsOnDefaultSink() const {}
 
 void Runtime::PrintReportOnDefaultSink() const {}
-#endif  // __linux__
+#endif  // __linux__ || __APPLE__
 
 using corpus_type = GenericDomainCorpusType;