move folly::uncaught_exceptions

Summary: It belongs with the other exception utilies. No need to keep it split out.

Reviewed By: Gownta

Differential Revision: D58552548

fbshipit-source-id: 63992b6e5e89b0afc22402b23ad8297fb0c4749c

folly/lang/BUCK

@@ -265,8 +265,6 @@ cpp_library(
     srcs = ["UncaughtExceptions.cpp"],
     headers = ["UncaughtExceptions.h"],
     exported_deps = [
-        "//folly:cpp_attributes",
-        "//folly:likely",
-        "//folly:portability",
+        ":exception",
     ],
 )

folly/lang/Exception.cpp

@@ -22,6 +22,41 @@
 
 #include <folly/lang/New.h>
 
+#if defined(__GLIBCXX__) || defined(_LIBCPP_VERSION)
+
+namespace __cxxabiv1 {
+
+struct __cxa_eh_globals {
+  void* caught_exceptions_;
+  unsigned int uncaught_exceptions_;
+};
+
+#if defined(__GLIBCXX__)
+extern "C" [[gnu::const]] __cxa_eh_globals* __cxa_get_globals() noexcept;
+#else
+extern "C" __cxa_eh_globals* __cxa_get_globals();
+#endif
+
+} // namespace __cxxabiv1
+
+#endif
+
+namespace folly {
+
+namespace detail {
+
+unsigned int* uncaught_exceptions_ptr() noexcept {
+  assert(kIsGlibcxx || kIsLibcpp);
+#if defined(__GLIBCXX__) || defined(_LIBCPP_VERSION)
+  return &__cxxabiv1::__cxa_get_globals()->uncaught_exceptions_;
+#endif
+  return nullptr;
+}
+
+} // namespace detail
+
+} // namespace folly
+
 //  Accesses std::type_info and std::exception_ptr internals. Since these vary
 //  by platform and library, import or copy the structure and function
 //  signatures from each platform and library.

folly/lang/Exception.h

@@ -310,6 +310,32 @@ catch_exception(Try&& t, Catch&& c, CatchA&&... a) noexcept(
 #endif
 }
 
+namespace detail {
+
+unsigned int* uncaught_exceptions_ptr() noexcept;
+
+} // namespace detail
+
+/// uncaught_exceptions
+///
+/// An accelerated version of std::uncaught_exceptions.
+///
+/// mimic: std::uncaught_exceptions, c++17
+[[FOLLY_ATTR_GNU_PURE]] FOLLY_EXPORT FOLLY_ALWAYS_INLINE int
+uncaught_exceptions() noexcept {
+#if defined(__APPLE__)
+  return std::uncaught_exceptions();
+#elif defined(_CPPLIB_VER)
+  return std::uncaught_exceptions();
+#elif defined(__has_feature) && !FOLLY_HAS_FEATURE(cxx_thread_local)
+  return std::uncaught_exceptions();
+#else
+  thread_local unsigned int* ct;
+  return to_signed(
+      FOLLY_LIKELY(!!ct) ? *ct : *(ct = detail::uncaught_exceptions_ptr()));
+#endif
+}
+
 namespace detail {
 #if FOLLY_APPLE_IOS
 #if __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_12_0

folly/lang/UncaughtExceptions.cpp

@@ -15,31 +15,3 @@
  */
 
 #include <folly/lang/UncaughtExceptions.h>
-
-#if defined(__GLIBCXX__) || defined(_LIBCPP_VERSION)
-
-namespace __cxxabiv1 {
-struct __cxa_eh_globals {
-  void* caught_exceptions_;
-  unsigned int uncaught_exceptions_;
-};
-extern "C" __cxa_eh_globals* __cxa_get_globals();
-} // namespace __cxxabiv1
-
-#endif
-
-namespace folly {
-
-namespace detail {
-
-unsigned int* uncaught_exceptions_ptr() noexcept {
-  assert(kIsGlibcxx || kIsLibcpp);
-#if defined(__GLIBCXX__) || defined(_LIBCPP_VERSION)
-  return &__cxxabiv1::__cxa_get_globals()->uncaught_exceptions_;
-#endif
-  return nullptr;
-}
-
-} // namespace detail
-
-} // namespace folly

folly/lang/UncaughtExceptions.h

@@ -16,38 +16,4 @@
 
 #pragma once
 
-#include <cassert>
-#include <exception>
-
-#include <folly/CppAttributes.h>
-#include <folly/Likely.h>
-#include <folly/Portability.h>
-
-namespace folly {
-
-namespace detail {
-
-unsigned int* uncaught_exceptions_ptr() noexcept;
-
-} // namespace detail
-
-//  uncaught_exceptions
-//
-//  An accelerated version of std::uncaught_exceptions.
-//
-//  mimic: std::uncaught_exceptions, c++17
-[[FOLLY_ATTR_GNU_PURE]] FOLLY_EXPORT FOLLY_ALWAYS_INLINE int
-uncaught_exceptions() noexcept {
-#if defined(__APPLE__)
-  return std::uncaught_exceptions();
-#elif defined(_CPPLIB_VER)
-  return std::uncaught_exceptions();
-#elif defined(__has_feature) && !FOLLY_HAS_FEATURE(cxx_thread_local)
-  return std::uncaught_exceptions();
-#else
-  thread_local unsigned int* ct;
-  return FOLLY_LIKELY(!!ct) ? *ct : *(ct = detail::uncaught_exceptions_ptr());
-#endif
-}
-
-} // namespace folly
+#include <folly/lang/Exception.h>

folly/lang/test/BUCK

@@ -220,27 +220,3 @@ cpp_unittest(
         "//folly/portability:gtest",
     ],
 )
-
-cpp_benchmark(
-    name = "uncaught_exceptions_bench",
-    srcs = ["UncaughtExceptionsBench.cpp"],
-    deps = [
-        "//folly:benchmark",
-        "//folly/lang:hint",
-        "//folly/lang:keep",
-        "//folly/lang:uncaught_exceptions",
-    ],
-)
-
-cpp_unittest(
-    name = "uncaught_exceptions_test",
-    srcs = ["UncaughtExceptionsTest.cpp"],
-    headers = [],
-    supports_static_listing = False,
-    deps = [
-        "//folly:conv",
-        "//folly/functional:invoke",
-        "//folly/lang:uncaught_exceptions",
-        "//folly/portability:gtest",
-    ],
-)

folly/lang/test/ExceptionBench.cpp

@@ -21,6 +21,14 @@
 #include <folly/Benchmark.h>
 #include <folly/lang/Keep.h>
 
+extern "C" FOLLY_KEEP int check_std_uncaught_exceptions() {
+  return std::uncaught_exceptions();
+}
+
+extern "C" FOLLY_KEEP int check_folly_uncaught_exceptions() {
+  return folly::uncaught_exceptions();
+}
+
 namespace {
 
 template <int I>
@@ -68,6 +76,26 @@ check_folly_exception_ptr_get_object_hint_vmi( //
   return folly::exception_ptr_get_object_hint<A0>(ptr, folly::tag<B1, C, B2>);
 }
 
+BENCHMARK(std_uncaught_exceptions, iters) {
+  int s = 0;
+  while (iters--) {
+    int u = std::uncaught_exceptions();
+    folly::compiler_must_not_predict(u);
+    s ^= u;
+  }
+  folly::compiler_must_not_elide(s);
+}
+
+BENCHMARK(folly_uncaught_exceptions, iters) {
+  int s = 0;
+  while (iters--) {
+    int u = folly::uncaught_exceptions();
+    folly::compiler_must_not_predict(u);
+    s ^= u;
+  }
+  folly::compiler_must_not_elide(s);
+}
+
 BENCHMARK(get_object_fail, iters) {
   folly::BenchmarkSuspender braces;
   bool result = false;

folly/lang/test/ExceptionTest.cpp

@@ -208,6 +208,26 @@ TEST_F(ExceptionTest, rethrow_current_exception) {
       std::runtime_error);
 }
 
+TEST_F(ExceptionTest, uncaught_exception) {
+  struct dtor {
+    unsigned expected;
+    explicit dtor(unsigned e) noexcept : expected{e} {}
+    ~dtor() {
+      EXPECT_EQ(expected, std::uncaught_exceptions());
+      EXPECT_EQ(expected, folly::uncaught_exceptions());
+    }
+  };
+  try {
+    dtor obj{0};
+  } catch (...) {
+  }
+  try {
+    dtor obj{1};
+    throw std::exception();
+  } catch (...) {
+  }
+}
+
 TEST_F(ExceptionTest, exception_ptr_empty) {
   auto ptr = std::exception_ptr();
   EXPECT_EQ(nullptr, folly::exception_ptr_get_type(ptr));