Use attribute testing to simplify portable attribute macros

Fixes #4025

PiperOrigin-RevId: 481186097
Change-Id: Id7d09e4626e5ccf564e8cfaa65581c1cd827918d

1 files changed, 37 insertions, 48 deletions

diff --git a/googletest/include/gtest/internal/gtest-port.h b/googletest/include/gtest/internal/gtest-port.h
index 3556fdb..50d4c41 100644
--- a/googletest/include/gtest/internal/gtest-port.h
+++ b/googletest/include/gtest/internal/gtest-port.h
@@ -642,6 +642,22 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
   default:  // NOLINT
 #endif
 
+// GTEST_HAVE_ATTRIBUTE_
+//
+// A function-like feature checking macro that is a wrapper around
+// `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a
+// nonzero constant integer if the attribute is supported or 0 if not.
+//
+// It evaluates to zero if `__has_attribute` is not defined by the compiler.
+//
+// GCC: https://gcc.gnu.org/gcc-5/changes.html
+// Clang: https://clang.llvm.org/docs/LanguageExtensions.html
+#ifdef __has_attribute
+#define GTEST_HAVE_ATTRIBUTE_(x) __has_attribute(x)
+#else
+#define GTEST_HAVE_ATTRIBUTE_(x) 0
+#endif
+
 // Use this annotation at the end of a struct/class definition to
 // prevent the compiler from optimizing away instances that are never
 // used.  This is useful when all interesting logic happens inside the
@@ -653,30 +669,22 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
 //
 // Also use it after a variable or parameter declaration to tell the
 // compiler the variable/parameter does not have to be used.
-#if defined(__GNUC__) && !defined(COMPILER_ICC)
-#define GTEST_ATTRIBUTE_UNUSED_ __attribute__((unused))
-#elif defined(__clang__)
-#if __has_attribute(unused)
+#if GTEST_HAVE_ATTRIBUTE_(unused)
 #define GTEST_ATTRIBUTE_UNUSED_ __attribute__((unused))
-#endif
-#endif
-#ifndef GTEST_ATTRIBUTE_UNUSED_
+#else
 #define GTEST_ATTRIBUTE_UNUSED_
 #endif
 
 // Use this annotation before a function that takes a printf format string.
-#if (defined(__GNUC__) || defined(__clang__)) && !defined(COMPILER_ICC)
-#if defined(__MINGW_PRINTF_FORMAT)
+#if GTEST_HAVE_ATTRIBUTE_(format) && defined(__MINGW_PRINTF_FORMAT)
 // MinGW has two different printf implementations. Ensure the format macro
 // matches the selected implementation. See
 // https://sourceforge.net/p/mingw-w64/wiki2/gnu%20printf/.
 #define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
-  __attribute__((                                             \
-      __format__(__MINGW_PRINTF_FORMAT, string_index, first_to_check)))
-#else
-#define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
-  __attribute__((__format__(__printf__, string_index, first_to_check)))
-#endif
+  __attribute__((format(__MINGW_PRINTF_FORMAT, string_index, first_to_check)))
+#elif GTEST_HAVE_ATTRIBUTE_(format)
+#define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check)   \
+  __attribute__((format(printf, string_index, first_to_check)))
 #else
 #define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check)
 #endif
@@ -686,11 +694,11 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
 // following the argument list:
 //
 //   Sprocket* AllocateSprocket() GTEST_MUST_USE_RESULT_;
-#if defined(__GNUC__) && !defined(COMPILER_ICC)
+#if GTEST_HAVE_ATTRIBUTE_(warn_unused_result)
 #define GTEST_MUST_USE_RESULT_ __attribute__((warn_unused_result))
 #else
 #define GTEST_MUST_USE_RESULT_
-#endif  // __GNUC__ && !COMPILER_ICC
+#endif
 
 // MS C++ compiler emits warning when a conditional expression is compile time
 // constant. In some contexts this warning is false positive and needs to be
@@ -746,7 +754,7 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
 #elif GTEST_CREATE_SHARED_LIBRARY
 #define GTEST_API_ __declspec(dllexport)
 #endif
-#elif __GNUC__ >= 4 || defined(__clang__)
+#elif GTEST_HAVE_ATTRIBUTE_(visibility)
 #define GTEST_API_ __attribute__((visibility("default")))
 #endif  // _MSC_VER
 
@@ -760,20 +768,17 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
 #define GTEST_DEFAULT_DEATH_TEST_STYLE "fast"
 #endif  // GTEST_DEFAULT_DEATH_TEST_STYLE
 
-#ifdef __GNUC__
+#if GTEST_HAVE_ATTRIBUTE_(noinline)
 // Ask the compiler to never inline a given function.
 #define GTEST_NO_INLINE_ __attribute__((noinline))
 #else
 #define GTEST_NO_INLINE_
 #endif
 
-#if defined(__clang__)
-// Nested ifs to avoid triggering MSVC warning.
-#if __has_attribute(disable_tail_calls)
+#if GTEST_HAVE_ATTRIBUTE_(disable_tail_calls)
 // Ask the compiler not to perform tail call optimization inside
 // the marked function.
 #define GTEST_NO_TAIL_CALL_ __attribute__((disable_tail_calls))
-#endif
 #elif __GNUC__
 #define GTEST_NO_TAIL_CALL_ \
   __attribute__((optimize("no-optimize-sibling-calls")))
@@ -792,50 +797,34 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
 
 // A function level attribute to disable checking for use of uninitialized
 // memory when built with MemorySanitizer.
-#if defined(__clang__)
-#if __has_feature(memory_sanitizer)
+#if GTEST_HAVE_ATTRIBUTE_(no_sanitize_memory)
 #define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ __attribute__((no_sanitize_memory))
 #else
 #define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
-#endif  // __has_feature(memory_sanitizer)
-#else
-#define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
-#endif  // __clang__
+#endif
 
 // A function level attribute to disable AddressSanitizer instrumentation.
-#if defined(__clang__)
-#if __has_feature(address_sanitizer)
+#if GTEST_HAVE_ATTRIBUTE_(no_sanitize_address)
 #define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_ \
   __attribute__((no_sanitize_address))
 #else
 #define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-#endif  // __has_feature(address_sanitizer)
-#else
-#define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
-#endif  // __clang__
+#endif
 
 // A function level attribute to disable HWAddressSanitizer instrumentation.
-#if defined(__clang__)
-#if __has_feature(hwaddress_sanitizer)
+#if GTEST_HAVE_ATTRIBUTE_(no_sanitize)
 #define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_ \
   __attribute__((no_sanitize("hwaddress")))
 #else
 #define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-#endif  // __has_feature(hwaddress_sanitizer)
-#else
-#define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
-#endif  // __clang__
+#endif
 
 // A function level attribute to disable ThreadSanitizer instrumentation.
-#if defined(__clang__)
-#if __has_feature(thread_sanitizer)
-#define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ __attribute__((no_sanitize_thread))
+#if GTEST_HAVE_ATTRIBUTE_(no_sanitize_thread)
+#define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ __attribute((no_sanitize_thread))
 #else
 #define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
-#endif  // __has_feature(thread_sanitizer)
-#else
-#define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
-#endif  // __clang__
+#endif
 
 namespace testing {