Export of internal Abseil changes

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f6fbb03bff276e72123e8590519079e87732ae62 by Abseil Team <absl-team@google.com>:

Replace static absl::Mutex with SpinLock in absl::Cords

to avoid static initializers by absl::Mutex destructors

PiperOrigin-RevId: 370694199

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654b7d9edfdc24f226990b2b46cbf91451a1d92a by Martijn Vels <mvels@google.com>:

Implement global data for CordzInfo in an ODR hardened way

This change puts the global data into a global list structure, and stores a reference to the global list in the handle itself. This hardens the implementation against ODR violations where info pointers are crossing dynamic library boundaries which are privately loaded.

PiperOrigin-RevId: 370673045

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712dba768e66ee2ba85d6010829c617cd2af6ba7 by Martijn Vels <mvels@google.com>:

Intrument Cord::operator= for Cordz

PiperOrigin-RevId: 370659149

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c0b347a2289e151b72680269332e264b8fa989c0 by Matt Kulukundis <kfm@google.com>:

Fix test guards for ABSL_ATTRIBUTE_RETURNS_NONNULL

PiperOrigin-RevId: 370594807

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c2bedaa3472ef223f907de2604f9b9b58852ec5f by Martijn Vels <mvels@google.com>:

Add new Cordz instrumentation on GetAppendRegion.

PiperOrigin-RevId: 370587761

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84fbfcc852697d509f6094482b86e84743a6b331 by Martijn Vels <mvels@google.com>:

Add instrumentation on Cord::Apppend(string_view)

PiperOrigin-RevId: 370576590

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9e077390b8ca2239e1cb7bfbe1d5a04f2fc11d30 by Abseil Team <absl-team@google.com>:

Google-internal changes only.

PiperOrigin-RevId: 370558424

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fb53c149eb2364ea34e3a67235f873866618b8ac by Matt Kulukundis <kfm@google.com>:

Update config.h macros with a few useful helpers to simplify version checking

PiperOrigin-RevId: 370557684

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abf8142e99b9ff7e15f6528a357f1005461950b0 by Martijn Vels <mvels@google.com>:

clang-format cord

PiperOrigin-RevId: 370549371

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e555985eabe63fcf0e980e9c433dd84caffec191 by Martijn Vels <mvels@google.com>:

Add MaybeUntrackCord() function

This function is near identical to the old UntrackCord() but allows info to be null, moving the cord.is_profiled() branch into CordzInfo.

PiperOrigin-RevId: 370528447

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3883538efe4601f7864bda70a50d868bb383c63b by Derek Mauro <dmauro@google.com>:

Internal change

PiperOrigin-RevId: 370503186

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a9514b65542fde1bc73584e6f3c1c4b3a05f215f by Derek Mauro <dmauro@google.com>:

Add -Winvalid-constexpr to warning options for LLVM

PiperOrigin-RevId: 370455171

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d8a3966de2cf15a2dc28e17e49a3d27d205eca92 by Martijn Vels <mvels@google.com>:

Add naive UniqueGenerator<T, kMaxValues, ...> to avoid flakes from dup random values.

PiperOrigin-RevId: 370179772

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46d0caa1a12b68a5998d4f919e20f0f83b9286f8 by Martijn Vels <mvels@google.com>:

Add new Cordz instrumentation on PrependTree.

PiperOrigin-RevId: 370138969
GitOrigin-RevId: f6fbb03bff276e72123e8590519079e87732ae62
Change-Id: Ifa4c00a5c7b01198ee367a3253bea6b66612135e

2 files changed, 30 insertions, 23 deletions

diff --git a/absl/base/attributes.h b/absl/base/attributes.h
index 294e5d0c..d710f287 100644
--- a/absl/base/attributes.h
+++ b/absl/base/attributes.h
@@ -281,10 +281,7 @@
 // ABSL_ATTRIBUTE_RETURNS_NONNULL
 //
 // Tells the compiler that a particular function never returns a null pointer.
-#if ABSL_HAVE_ATTRIBUTE(returns_nonnull) || \
-    (defined(__GNUC__) && \
-     (__GNUC__ > 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)) && \
-     !defined(__clang__))
+#if ABSL_HAVE_ATTRIBUTE(returns_nonnull)
 #define ABSL_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull))
 #else
 #define ABSL_ATTRIBUTE_RETURNS_NONNULL
@@ -622,7 +619,7 @@
 #if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
 #define ABSL_FALLTHROUGH_INTENDED [[clang::fallthrough]]
 #endif
-#elif defined(__GNUC__) && __GNUC__ >= 7
+#elif ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(7, 0)
 #define ABSL_FALLTHROUGH_INTENDED [[gnu::fallthrough]]
 #endif
 
diff --git a/absl/base/config.h b/absl/base/config.h
index 7abc75a6..0524196d 100644
--- a/absl/base/config.h
+++ b/absl/base/config.h
@@ -166,6 +166,22 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #define ABSL_HAVE_FEATURE(f) 0
 #endif
 
+// Portable check for GCC minimum version:
+// https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
+#if defined(__GNUC__) && defined(__GNUC_MINOR__)
+#define ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(x, y) \
+  (__GNUC__ > (x) || __GNUC__ == (x) && __GNUC_MINOR__ >= (y))
+#else
+#define ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(x, y) 0
+#endif
+
+#if defined(__clang__) && defined(__clang_major__) && defined(__clang_minor__)
+#define ABSL_INTERNAL_HAVE_MIN_CLANG_VERSION(x, y) \
+  (__clang_major__ > (x) || __clang_major__ == (x) && __clang_minor__ >= (y))
+#else
+#define ABSL_INTERNAL_HAVE_MIN_CLANG_VERSION(x, y) 0
+#endif
+
 // ABSL_HAVE_TLS is defined to 1 when __thread should be supported.
 // We assume __thread is supported on Linux when compiled with Clang or compiled
 // against libstdc++ with _GLIBCXX_HAVE_TLS defined.
@@ -183,10 +199,9 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 // gcc >= 4.8.1 using libstdc++, and Visual Studio.
 #ifdef ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE
 #error ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE cannot be directly set
-#elif defined(_LIBCPP_VERSION) ||                                        \
-    (!defined(__clang__) && defined(__GNUC__) && defined(__GLIBCXX__) && \
-     (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))) ||        \
-    defined(_MSC_VER)
+#elif defined(_LIBCPP_VERSION) || defined(_MSC_VER) || \
+    (!defined(__clang__) && defined(__GLIBCXX__) &&    \
+     ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(4, 8))
 #define ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE 1
 #endif
 
@@ -205,10 +220,9 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #error ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE cannot be directly set
 #elif defined(ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE)
 #error ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE cannot directly set
-#elif (defined(__clang__) && defined(_LIBCPP_VERSION)) ||        \
-    (!defined(__clang__) && defined(__GNUC__) &&                 \
-     (__GNUC__ > 7 || (__GNUC__ == 7 && __GNUC_MINOR__ >= 4)) && \
-     (defined(_LIBCPP_VERSION) || defined(__GLIBCXX__))) ||      \
+#elif (defined(__clang__) && defined(_LIBCPP_VERSION)) ||                \
+    (!defined(__clang__) && ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(7, 4) && \
+     (defined(_LIBCPP_VERSION) || defined(__GLIBCXX__))) ||              \
     (defined(_MSC_VER) && !defined(__NVCC__))
 #define ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE 1
 #define ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE 1
@@ -222,7 +236,7 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 #if ABSL_INTERNAL_HAS_KEYWORD(__builtin_LINE) && \
     ABSL_INTERNAL_HAS_KEYWORD(__builtin_FILE)
 #define ABSL_HAVE_SOURCE_LOCATION_CURRENT 1
-#elif defined(__GNUC__) && __GNUC__ >= 5
+#elif ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(5, 0)
 #define ABSL_HAVE_SOURCE_LOCATION_CURRENT 1
 #endif
 #endif
@@ -319,25 +333,21 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 // For further details, consult the compiler's documentation.
 #ifdef ABSL_HAVE_EXCEPTIONS
 #error ABSL_HAVE_EXCEPTIONS cannot be directly set.
-
-#elif defined(__clang__)
-
-#if __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 6)
+#elif ABSL_INTERNAL_HAVE_MIN_CLANG_VERSION(3, 6)
 // Clang >= 3.6
 #if ABSL_HAVE_FEATURE(cxx_exceptions)
 #define ABSL_HAVE_EXCEPTIONS 1
 #endif  // ABSL_HAVE_FEATURE(cxx_exceptions)
-#else
+#elif defined(__clang__)
 // Clang < 3.6
 // http://releases.llvm.org/3.6.0/tools/clang/docs/ReleaseNotes.html#the-exceptions-macro
 #if defined(__EXCEPTIONS) && ABSL_HAVE_FEATURE(cxx_exceptions)
 #define ABSL_HAVE_EXCEPTIONS 1
 #endif  // defined(__EXCEPTIONS) && ABSL_HAVE_FEATURE(cxx_exceptions)
-#endif  // __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 6)
-
 // Handle remaining special cases and default to exceptions being supported.
-#elif !(defined(__GNUC__) && (__GNUC__ < 5) && !defined(__EXCEPTIONS)) &&    \
-    !(defined(__GNUC__) && (__GNUC__ >= 5) && !defined(__cpp_exceptions)) && \
+#elif !(defined(__GNUC__) && (__GNUC__ < 5) && !defined(__EXCEPTIONS)) && \
+    !(ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(5, 0) &&                        \
+      !defined(__cpp_exceptions)) &&                                      \
     !(defined(_MSC_VER) && !defined(_CPPUNWIND))
 #define ABSL_HAVE_EXCEPTIONS 1
 #endif