Merge pull request #2742 from kuzkry:c++17-type-printers

BUILD.bazel

@@ -103,6 +103,7 @@ cc_library(
             "@com_google_absl//absl/debugging:stacktrace",
             "@com_google_absl//absl/debugging:symbolize",
             "@com_google_absl//absl/strings",
+            "@com_google_absl//absl/types:any",
             "@com_google_absl//absl/types:optional",
             "@com_google_absl//absl/types:variant",
         ],

googletest/include/gtest/gtest-printers.h

@@ -113,8 +113,6 @@
 
 #if GTEST_HAS_ABSL
 #include "absl/strings/string_view.h"
-#include "absl/types/optional.h"
-#include "absl/types/variant.h"
 #endif  // GTEST_HAS_ABSL
 
 namespace testing {
@@ -596,14 +594,42 @@ class UniversalPrinter {
   GTEST_DISABLE_MSC_WARNINGS_POP_()
 };
 
-#if GTEST_HAS_ABSL
+#if GTEST_INTERNAL_HAS_ANY
+
+// Printer for std::any / absl::any
 
-// Printer for absl::optional
+template <>
+class UniversalPrinter<Any> {
+ public:
+  static void Print(const Any& value, ::std::ostream* os) {
+    if (value.has_value()) {
+      *os << "value of type " << GetTypeName(value);
+    } else {
+      *os << "no value";
+    }
+  }
+
+ private:
+  static std::string GetTypeName(const Any& value) {
+#if GTEST_HAS_RTTI
+    return internal::GetTypeName(value.type());
+#else
+    static_cast<void>(value);  // possibly unused
+    return "<unknown_type>";
+#endif  // GTEST_HAS_RTTI
+  }
+};
+
+#endif  // GTEST_INTERNAL_HAS_ANY
+
+#if GTEST_INTERNAL_HAS_OPTIONAL
+
+// Printer for std::optional / absl::optional
 
 template <typename T>
-class UniversalPrinter<::absl::optional<T>> {
+class UniversalPrinter<Optional<T>> {
  public:
-  static void Print(const ::absl::optional<T>& value, ::std::ostream* os) {
+  static void Print(const Optional<T>& value, ::std::ostream* os) {
     *os << '(';
     if (!value) {
       *os << "nullopt";
@@ -614,14 +640,22 @@ class UniversalPrinter<::absl::optional<T>> {
   }
 };
 
-// Printer for absl::variant
+#endif  // GTEST_INTERNAL_HAS_OPTIONAL
+
+#if GTEST_INTERNAL_HAS_VARIANT
+
+// Printer for std::variant / absl::variant
 
 template <typename... T>
-class UniversalPrinter<::absl::variant<T...>> {
+class UniversalPrinter<Variant<T...>> {
  public:
-  static void Print(const ::absl::variant<T...>& value, ::std::ostream* os) {
+  static void Print(const Variant<T...>& value, ::std::ostream* os) {
     *os << '(';
-    absl::visit(Visitor{os}, value);
+#if GTEST_HAS_ABSL
+    absl::visit(Visitor{os, value.index()}, value);
+#else
+    std::visit(Visitor{os, value.index()}, value);
+#endif  // GTEST_HAS_ABSL
     *os << ')';
   }
 
@@ -629,14 +663,16 @@ class UniversalPrinter<::absl::variant<T...>> {
   struct Visitor {
     template <typename U>
     void operator()(const U& u) const {
-      *os << "'" << GetTypeName<U>() << "' with value ";
+      *os << "'" << GetTypeName<U>() << "(index = " << index
+          << ")' with value ";
       UniversalPrint(u, os);
     }
     ::std::ostream* os;
+    std::size_t index;
   };
 };
 
-#endif  // GTEST_HAS_ABSL
+#endif  // GTEST_INTERNAL_HAS_VARIANT
 
 // UniversalPrintArray(begin, len, os) prints an array of 'len'
 // elements, starting at address 'begin'.

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

@@ -199,9 +199,18 @@
 //                                        suppressed (constant conditional).
 //   GTEST_INTENTIONAL_CONST_COND_POP_  - finish code section where MSVC C4127
 //                                        is suppressed.
+//   GTEST_INTERNAL_HAS_ANY - for enabling UniversalPrinter<std::any> or
+//                            UniversalPrinter<absl::any> specializations.
+//   GTEST_INTERNAL_HAS_OPTIONAL - for enabling UniversalPrinter<std::optional>
+//   or
+//                                 UniversalPrinter<absl::optional>
+//                                 specializations.
 //   GTEST_INTERNAL_HAS_STRING_VIEW - for enabling Matcher<std::string_view> or
 //                                    Matcher<absl::string_view>
 //                                    specializations.
+//   GTEST_INTERNAL_HAS_VARIANT - for enabling UniversalPrinter<std::variant> or
+//                                UniversalPrinter<absl::variant>
+//                                specializations.
 //
 // Synchronization:
 //   Mutex, MutexLock, ThreadLocal, GetThreadCount()
@@ -2244,6 +2253,64 @@ const char* StringFromGTestEnv(const char* flag, const char* default_val);
 #endif  // !defined(GTEST_INTERNAL_DEPRECATED)
 
 #if GTEST_HAS_ABSL
+// Always use absl::any for UniversalPrinter<> specializations if googletest
+// is built with absl support.
+#define GTEST_INTERNAL_HAS_ANY 1
+#include "absl/types/any.h"
+namespace testing {
+namespace internal {
+using Any = ::absl::any;
+}  // namespace internal
+}  // namespace testing
+#else
+#ifdef __has_include
+#if __has_include(<any>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::any for UniversalPrinter<>
+// specializations.
+#define GTEST_INTERNAL_HAS_ANY 1
+#include <any>
+namespace testing {
+namespace internal {
+using Any = ::std::any;
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::any is not
+// supported.
+#endif  // __has_include(<any>) && __cplusplus >= 201703L
+#endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
+#if GTEST_HAS_ABSL
+// Always use absl::optional for UniversalPrinter<> specializations if
+// googletest is built with absl support.
+#define GTEST_INTERNAL_HAS_OPTIONAL 1
+#include "absl/types/optional.h"
+namespace testing {
+namespace internal {
+template <typename T>
+using Optional = ::absl::optional<T>;
+}  // namespace internal
+}  // namespace testing
+#else
+#ifdef __has_include
+#if __has_include(<optional>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::optional for UniversalPrinter<>
+// specializations.
+#define GTEST_INTERNAL_HAS_OPTIONAL 1
+#include <optional>
+namespace testing {
+namespace internal {
+template <typename T>
+using Optional = ::std::optional<T>;
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::optional is not
+// supported.
+#endif  // __has_include(<optional>) && __cplusplus >= 201703L
+#endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
+#if GTEST_HAS_ABSL
 // Always use absl::string_view for Matcher<> specializations if googletest
 // is built with absl support.
 # define GTEST_INTERNAL_HAS_STRING_VIEW 1
@@ -2271,4 +2338,33 @@ using StringView = ::std::string_view;
 # endif  // __has_include
 #endif  // GTEST_HAS_ABSL
 
+#if GTEST_HAS_ABSL
+// Always use absl::variant for UniversalPrinter<> specializations if googletest
+// is built with absl support.
+#define GTEST_INTERNAL_HAS_VARIANT 1
+#include "absl/types/variant.h"
+namespace testing {
+namespace internal {
+template <typename... T>
+using Variant = ::absl::variant<T...>;
+}  // namespace internal
+}  // namespace testing
+#else
+#ifdef __has_include
+#if __has_include(<variant>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::variant for UniversalPrinter<>
+// specializations.
+#define GTEST_INTERNAL_HAS_VARIANT 1
+#include <variant>
+namespace testing {
+namespace internal {
+template <typename... T>
+using Variant = ::std::variant<T...>;
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::variant is not supported.
+#endif  // __has_include(<variant>) && __cplusplus >= 201703L
+#endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
 #endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_

googletest/include/gtest/internal/gtest-type-util.h

@@ -64,34 +64,38 @@ inline std::string CanonicalizeForStdLibVersioning(std::string s) {
   return s;
 }
 
-// GetTypeName<T>() returns a human-readable name of type T.
-// NB: This function is also used in Google Mock, so don't move it inside of
-// the typed-test-only section below.
-template <typename T>
-std::string GetTypeName() {
-# if GTEST_HAS_RTTI
-
-  const char* const name = typeid(T).name();
-#  if GTEST_HAS_CXXABI_H_ || defined(__HP_aCC)
+#if GTEST_HAS_RTTI
+// GetTypeName(const std::type_info&) returns a human-readable name of type T.
+inline std::string GetTypeName(const std::type_info& type) {
+  const char* const name = type.name();
+#if GTEST_HAS_CXXABI_H_ || defined(__HP_aCC)
   int status = 0;
   // gcc's implementation of typeid(T).name() mangles the type name,
   // so we have to demangle it.
-#   if GTEST_HAS_CXXABI_H_
+#if GTEST_HAS_CXXABI_H_
   using abi::__cxa_demangle;
-#   endif  // GTEST_HAS_CXXABI_H_
+#endif  // GTEST_HAS_CXXABI_H_
   char* const readable_name = __cxa_demangle(name, nullptr, nullptr, &status);
   const std::string name_str(status == 0 ? readable_name : name);
   free(readable_name);
   return CanonicalizeForStdLibVersioning(name_str);
-#  else
+#else
   return name;
-#  endif  // GTEST_HAS_CXXABI_H_ || __HP_aCC
-
-# else
+#endif  // GTEST_HAS_CXXABI_H_ || __HP_aCC
+}
+#endif  // GTEST_HAS_RTTI
 
+// GetTypeName<T>() returns a human-readable name of type T if and only if
+// RTTI is enabled, otherwise it returns a dummy type name.
+// NB: This function is also used in Google Mock, so don't move it inside of
+// the typed-test-only section below.
+template <typename T>
+std::string GetTypeName() {
+#if GTEST_HAS_RTTI
+  return GetTypeName(typeid(T));
+#else
   return "<type>";
-
-# endif  // GTEST_HAS_RTTI
+#endif  // GTEST_HAS_RTTI
 }
 
 #if GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P

googletest/test/googletest-printers-test.cc

@@ -1531,32 +1531,65 @@ TEST(UniversalTersePrintTupleFieldsToStringsTestWithStd, PrintsTersely) {
   EXPECT_EQ("\"a\"", result[1]);
 }
 
-#if GTEST_HAS_ABSL
+#if GTEST_INTERNAL_HAS_ANY
+class PrintAnyTest : public ::testing::Test {
+ protected:
+  template <typename T>
+  static std::string ExpectedTypeName() {
+#if GTEST_HAS_RTTI
+    return internal::GetTypeName<T>();
+#else
+    return "<unknown_type>";
+#endif  // GTEST_HAS_RTTI
+  }
+};
+
+TEST_F(PrintAnyTest, Empty) {
+  internal::Any any;
+  EXPECT_EQ("no value", PrintToString(any));
+}
+
+TEST_F(PrintAnyTest, NonEmpty) {
+  internal::Any any;
+  constexpr int val1 = 10;
+  const std::string val2 = "content";
+
+  any = val1;
+  EXPECT_EQ("value of type " + ExpectedTypeName<int>(), PrintToString(any));
+
+  any = val2;
+  EXPECT_EQ("value of type " + ExpectedTypeName<std::string>(),
+            PrintToString(any));
+}
+#endif  // GTEST_INTERNAL_HAS_ANY
 
+#if GTEST_INTERNAL_HAS_OPTIONAL
 TEST(PrintOptionalTest, Basic) {
-  absl::optional<int> value;
+  internal::Optional<int> value;
   EXPECT_EQ("(nullopt)", PrintToString(value));
   value = {7};
   EXPECT_EQ("(7)", PrintToString(value));
-  EXPECT_EQ("(1.1)", PrintToString(absl::optional<double>{1.1}));
-  EXPECT_EQ("(\"A\")", PrintToString(absl::optional<std::string>{"A"}));
+  EXPECT_EQ("(1.1)", PrintToString(internal::Optional<double>{1.1}));
+  EXPECT_EQ("(\"A\")", PrintToString(internal::Optional<std::string>{"A"}));
 }
+#endif  // GTEST_INTERNAL_HAS_OPTIONAL
 
+#if GTEST_INTERNAL_HAS_VARIANT
 struct NonPrintable {
   unsigned char contents = 17;
 };
 
 TEST(PrintOneofTest, Basic) {
-  using Type = absl::variant<int, StreamableInGlobal, NonPrintable>;
-  EXPECT_EQ("('int' with value 7)", PrintToString(Type(7)));
-  EXPECT_EQ("('StreamableInGlobal' with value StreamableInGlobal)",
+  using Type = internal::Variant<int, StreamableInGlobal, NonPrintable>;
+  EXPECT_EQ("('int(index = 0)' with value 7)", PrintToString(Type(7)));
+  EXPECT_EQ("('StreamableInGlobal(index = 1)' with value StreamableInGlobal)",
             PrintToString(Type(StreamableInGlobal{})));
   EXPECT_EQ(
-      "('testing::gtest_printers_test::NonPrintable' with value 1-byte object "
-      "<11>)",
+      "('testing::gtest_printers_test::NonPrintable(index = 2)' with value "
+      "1-byte object <11>)",
       PrintToString(Type(NonPrintable{})));
 }
-#endif  // GTEST_HAS_ABSL
+#endif  // GTEST_INTERNAL_HAS_VARIANT
 namespace {
 class string_ref;