Rollback: Improve detection for wchar_t and wstring support.

Add a configurable `GTEST_HAS_WCHAR` option to control whether to provide `wchar_t*` overloads for `PrintTo`. Check implementation-specific standard library defines to determine proper defaults for  `GTEST_HAS_WCHAR` and `GTEST_HAS_STD_WSTRING` and to produce compile errors if the users pick a configuration that depends on unavailable standard library features.

PiperOrigin-RevId: 958668507
Change-Id: Ic9b78d83fb455dff7d993303d54a0bde749a8cd8

googletest/include/gtest/gtest-printers.h

@@ -676,13 +676,18 @@ inline void PrintTo(char32_t* s, ::std::ostream* os) {
   PrintTo(ImplicitCast_<const char32_t*>(s), os);
 }
 
-#if GTEST_HAS_WCHAR
+// MSVC can be configured to define wchar_t as a typedef of unsigned
+// short.  It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native
+// type.  When wchar_t is a typedef, defining an overload for const
+// wchar_t* would cause unsigned short* be printed as a wide string,
+// possibly causing invalid memory accesses.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
 // Overloads for wide C strings
 GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
 inline void PrintTo(wchar_t* s, ::std::ostream* os) {
   PrintTo(ImplicitCast_<const wchar_t*>(s), os);
 }
-#endif  // GTEST_HAS_WCHAR
+#endif
 
 // Overload for C arrays.  Multi-dimensional arrays are printed
 // properly.

googletest/include/gtest/internal/gtest-port.h

@@ -80,11 +80,6 @@
 //                              is/isn't available.
 //   GTEST_HAS_RTTI           - Define it to 1/0 to indicate that RTTI is/isn't
 //                              enabled.
-//   GTEST_HAS_WCHAR          - Define it to 1/0 to indicate that wide
-//                              characters are/aren't supported. (Google Test
-//                              can be used where std::char_traits<wchar_t> and
-//                              libc wchar_t functions (putwc, getwc, etc.) are
-//                              unavailable.)
 //   GTEST_HAS_STD_WSTRING    - Define it to 1/0 to indicate that
 //                              std::wstring does/doesn't work (Google Test can
 //                              be used where std::wstring is unavailable).
@@ -504,89 +499,22 @@ typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
 #endif  // defined(_MSC_VER) || defined(__BORLANDC__)
 #endif  // GTEST_HAS_EXCEPTIONS
 
-// 1. Calculate default GTEST_HAS_WCHAR and GTEST_HAS_STD_WSTRING values based
+#ifndef GTEST_HAS_STD_WSTRING
-// on compiler / STL capabilities.
+// The user didn't tell us whether ::std::wstring is available, so we need
-#if defined(_MSC_VER)
+// to figure it out.
-// MSVC always supports ::std::wstring.
-#define GTEST_HAS_STD_WSTRING_DEFAULT 1
-// MSVC either defines wchar_t as a typedef of unsigned short, or as a native
-// type (in which case, it defines _NATIVE_WCHAR_T_DEFINED). When wchar_t is a
-// typedef, defining an overload for const wchar_t* would cause unsigned short*
-// be printed as a wide string, possibly causing invalid memory accesses, so we
-// omit wchar_t overloads in that case.
-#if defined(_NATIVE_WCHAR_T_DEFINED)
-#define GTEST_HAS_WCHAR_DEFAULT 1
-#else
-#define GTEST_HAS_WCHAR_DEFAULT 0
-#endif
-
-#elif defined(_LIBCPP_VERSION)
-#if _LIBCPP_HAS_WIDE_CHARACTERS
-#define GTEST_HAS_WCHAR_DEFAULT 1
-#define GTEST_HAS_STD_WSTRING_DEFAULT 1
-#else
-#define GTEST_HAS_WCHAR_DEFAULT 0
-#define GTEST_HAS_STD_WSTRING_DEFAULT 0
-#endif
-
-#elif defined(__GLIBCXX__)
-#if _GLIBCXX_USE_WCHAR_T
-#define GTEST_HAS_WCHAR_DEFAULT 1
-#define GTEST_HAS_STD_WSTRING_DEFAULT 1
-#else
-#define GTEST_HAS_WCHAR_DEFAULT 0
-#define GTEST_HAS_STD_WSTRING_DEFAULT 0
-#endif
-
-#else
-// Unknown standard library implementation; fall back to a list of OSes known to
-// not support wide characters.
-//
 // Cygwin 1.7 and below doesn't support ::std::wstring.
 // Solaris' libc++ doesn't support it either.  Android has
 // no support for it at least as recent as Froyo (2.2).
-//
-// Always let the user override the defaults in this case; they might have more
-// information about what's supported than we do.
 #if (!(defined(GTEST_OS_LINUX_ANDROID) || defined(GTEST_OS_CYGWIN) || \
        defined(GTEST_OS_SOLARIS) || defined(GTEST_OS_HAIKU) ||        \
        defined(GTEST_OS_ESP32) || defined(GTEST_OS_ESP8266) ||        \
        defined(GTEST_OS_XTENSA) || defined(GTEST_OS_QURT) ||          \
        defined(GTEST_OS_NXP_QN9090) || defined(GTEST_OS_NRF52)))
-#define GTEST_HAS_WCHAR_DEFAULT 1
+#define GTEST_HAS_STD_WSTRING 1
-#define GTEST_HAS_STD_WSTRING_DEFAULT 1
 #else
-#define GTEST_HAS_WCHAR_DEFAULT 0
+#define GTEST_HAS_STD_WSTRING 0
-#define GTEST_HAS_STD_WSTRING_DEFAULT 0
-#endif
-#endif
-
-// 2. Validate explicit user overrides (if user passed -DGTEST_HAS_*=1)
-#if defined(GTEST_HAS_WCHAR) && GTEST_HAS_WCHAR
-#if defined(_MSC_VER) && !defined(_NATIVE_WCHAR_T_DEFINED)
-#error Cannot explicitly enable GTEST_HAS_WCHAR when wchar_t is a typedef.
-#elif defined(_LIBCPP_VERSION) && !_LIBCPP_HAS_WIDE_CHARACTERS
-#error Cannot explicitly enable GTEST_HAS_WCHAR without libc++ wide character support.
-#elif defined(__GLIBCXX__) && !_GLIBCXX_USE_WCHAR_T
-#error Cannot explicitly enable GTEST_HAS_WCHAR without libstdc++ wide character support.
-#endif
-#endif
-
-#if defined(GTEST_HAS_STD_WSTRING) && GTEST_HAS_STD_WSTRING
-#if defined(_LIBCPP_VERSION) && !_LIBCPP_HAS_WIDE_CHARACTERS
-#error Cannot explicitly enable GTEST_HAS_STD_WSTRING without libc++ wide character support.
-#elif defined(__GLIBCXX__) && !_GLIBCXX_USE_WCHAR_T
-#error Cannot explicitly enable GTEST_HAS_STD_WSTRING without libstdc++ wide character support.
-#endif
-#endif
-
-// 3. Set final values if not explicitly overridden by user
-#if !defined(GTEST_HAS_WCHAR)
-#define GTEST_HAS_WCHAR GTEST_HAS_WCHAR_DEFAULT
-#endif
-#if !defined(GTEST_HAS_STD_WSTRING)
-#define GTEST_HAS_STD_WSTRING GTEST_HAS_STD_WSTRING_DEFAULT
 #endif
+#endif  // GTEST_HAS_STD_WSTRING
 
 #ifndef GTEST_HAS_FILE_SYSTEM
 // Most platforms support a file system.

googletest/src/gtest-printers.cc

@@ -445,10 +445,16 @@ void PrintTo(const char16_t* s, ostream* os) { PrintCStringTo(s, os); }
 
 void PrintTo(const char32_t* s, ostream* os) { PrintCStringTo(s, os); }
 
-#if GTEST_HAS_WCHAR
+// MSVC compiler can be configured to define whar_t as a typedef
+// of unsigned short. Defining an overload for const wchar_t* in that case
+// would cause pointers to unsigned shorts be printed as wide strings,
+// possibly accessing more memory than intended and causing invalid
+// memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
+// wchar_t is implemented as a native type.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
 // Prints the given wide C string to the ostream.
 void PrintTo(const wchar_t* s, ostream* os) { PrintCStringTo(s, os); }
-#endif  // GTEST_HAS_WCHAR
+#endif  // wchar_t is native
 
 namespace {
 

googletest/test/googletest-printers-test.cc

@@ -648,7 +648,13 @@ TEST(PrintU32StringTest, EscapesProperly) {
             Print(p));
 }
 
-#if GTEST_HAS_WCHAR
+// MSVC compiler can be configured to define whar_t as a typedef
+// of unsigned short. Defining an overload for const wchar_t* in that case
+// would cause pointers to unsigned shorts be printed as wide strings,
+// possibly accessing more memory than intended and causing invalid
+// memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
+// wchar_t is implemented as a native type.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
 
 // const wchar_t*.
 TEST(PrintWideCStringTest, Const) {
@@ -679,7 +685,7 @@ TEST(PrintWideCStringTest, EscapesProperly) {
                 "\\n\\r\\t\\v\\xD3\\x576\\x8D3\\xC74D a\"",
             Print(static_cast<const wchar_t*>(s)));
 }
-#endif  // GTEST_HAS_WCHAR
+#endif  // native wchar_t
 
 // Tests printing pointers to other char types.