Export of internal Abseil changes

--
739f9fb80212c21c015fec473e9e29803a156ef9 by Derek Mauro <dmauro@google.com>:

Define FlagStateInterface::~FlagStateInterface() in the translation
unit in which it is actually declared

Fixes #717

PiperOrigin-RevId: 319083605

--
913ef1f23113268b22d636d3ae3b992862efdb1a by Derek Mauro <dmauro@google.com>:

Fix ABSL_LOCK_RETURNED statement

PiperOrigin-RevId: 319078667

--
a43b1413da1770d638147c73e7e1693cfaf869c7 by Derek Mauro <dmauro@google.com>:

Fix redeclaration ‘absl::Cord::InlineRep::kMaxInline’, which differs in ‘constexpr’
Fixes #725

PiperOrigin-RevId: 319060910

--
1ad7d491a80f6c9de78a6fc20f09b7765d224503 by Abseil Team <absl-team@google.com>:

Make absl SpinLock trivially destructible when possible

PiperOrigin-RevId: 319049456

--
659ecad3578dfa669854a82279fa590002bdb37f by Derek Mauro <dmauro@google.com>:

Remove the static initialization of global variables used by absl::Mutex
as requested by Chromium

PiperOrigin-RevId: 319031204

--
609c491d8bb4f8bb3b44c5a4c0bee51c583df24c by Abseil Team <absl-team@google.com>:

Add implementation of %a and %A to absl::StrFormat.

Prior to this it just fell back to sprintf.

PiperOrigin-RevId: 318888039

--
5e8ae6392bcd135248aac14c4b9f2a5116868678 by Abseil Team <absl-team@google.com>:

Google-internal changes only.

PiperOrigin-RevId: 318857077

--
4a2578e33e8442954e29e5f0380ddfcf0f033f0d by Greg Falcon <gfalcon@google.com>:

Change of enum constants to accommodate internal change.

PiperOrigin-RevId: 318844716

--
4b578b102816260c213675759f4c15911735578a by Abseil Team <absl-team@google.com>:

Internal change

PiperOrigin-RevId: 318704453

--
0ee82fd24d548b260c9229fa1f54571dae1dfa24 by Gennadiy Rozental <rogeeff@google.com>:

Allow lookup of retired flags.

At the moment we issue warning on attempt to find a retired flag. This way we can't even check if flag is retired without issuing the warning.

With this change we will only issue the warning if one tries to access any functionality of retired flag but it's name "is retired" status, and type.

PiperOrigin-RevId: 318605017

--
3e35fe9b4c79f636fa328c59e2aabb93e29b7c99 by Abseil Team <absl-team@google.com>:

Fix error return from InstallSymbolDecorator().

PiperOrigin-RevId: 318490405

--
ae46063f3eb2998cb961f62a359d932e5908a4bc by Abseil Team <absl-team@google.com>:

Do not make copies of iterated collection elements into the loop variable.

PiperOrigin-RevId: 318423139

--
d06a075a12aab5f6ab98474677ce50d588b21de3 by Abseil Team <absl-team@google.com>:

add missing word making the error code better English

PiperOrigin-RevId: 318335052
GitOrigin-RevId: 739f9fb80212c21c015fec473e9e29803a156ef9
Change-Id: Id77a0a4b1959036b00555deef40e82d51884fbc1

1 files changed, 221 insertions, 9 deletions

diff --git a/absl/strings/internal/str_format/convert_test.cc b/absl/strings/internal/str_format/convert_test.cc
index e37d0546..488d4cd4 100644
--- a/absl/strings/internal/str_format/convert_test.cc
+++ b/absl/strings/internal/str_format/convert_test.cc
@@ -12,6 +12,7 @@
 #include "gtest/gtest.h"
 #include "absl/base/internal/raw_logging.h"
 #include "absl/strings/internal/str_format/bind.h"
+#include "absl/strings/match.h"
 #include "absl/types/optional.h"
 
 namespace absl {
@@ -19,6 +20,13 @@ ABSL_NAMESPACE_BEGIN
 namespace str_format_internal {
 namespace {
 
+struct NativePrintfTraits {
+  bool hex_float_has_glibc_rounding;
+  bool hex_float_prefers_denormal_repr;
+  bool hex_float_uses_minimal_precision_when_not_specified;
+  bool hex_float_optimizes_leading_digit_bit_count;
+};
+
 template <typename T, size_t N>
 size_t ArraySize(T (&)[N]) {
   return N;
@@ -118,6 +126,63 @@ std::string StrPrint(const char *format, ...) {
   return result;
 }
 
+NativePrintfTraits VerifyNativeImplementationImpl() {
+  NativePrintfTraits result;
+
+  // >>> hex_float_has_glibc_rounding. To have glibc's rounding behavior we need
+  // to meet three requirements:
+  //
+  //   - The threshold for rounding up is 8 (for e.g. MSVC uses 9).
+  //   - If the digits lower than than the 8 are non-zero then we round up.
+  //   - If the digits lower than the 8 are all zero then we round toward even.
+  //
+  // The numbers below represent all the cases covering {below,at,above} the
+  // threshold (8) with both {zero,non-zero} lower bits and both {even,odd}
+  // preceding digits.
+  const double d0079 = 65657.0;  // 0x1.0079p+16
+  const double d0179 = 65913.0;  // 0x1.0179p+16
+  const double d0080 = 65664.0;  // 0x1.0080p+16
+  const double d0180 = 65920.0;  // 0x1.0180p+16
+  const double d0081 = 65665.0;  // 0x1.0081p+16
+  const double d0181 = 65921.0;  // 0x1.0181p+16
+  result.hex_float_has_glibc_rounding =
+      StartsWith(StrPrint("%.2a", d0079), "0x1.00") &&
+      StartsWith(StrPrint("%.2a", d0179), "0x1.01") &&
+      StartsWith(StrPrint("%.2a", d0080), "0x1.00") &&
+      StartsWith(StrPrint("%.2a", d0180), "0x1.02") &&
+      StartsWith(StrPrint("%.2a", d0081), "0x1.01") &&
+      StartsWith(StrPrint("%.2a", d0181), "0x1.02");
+
+  // >>> hex_float_prefers_denormal_repr. Formatting `denormal` on glibc yields
+  // "0x0.0000000000001p-1022", whereas on std libs that don't use denormal
+  // representation it would either be 0x1p-1074 or 0x1.0000000000000-1074.
+  const double denormal = std::numeric_limits<double>::denorm_min();
+  result.hex_float_prefers_denormal_repr =
+      StartsWith(StrPrint("%a", denormal), "0x0.0000000000001");
+
+  // >>> hex_float_uses_minimal_precision_when_not_specified. Some (non-glibc)
+  // libs will format the following as "0x1.0079000000000p+16".
+  result.hex_float_uses_minimal_precision_when_not_specified =
+      (StrPrint("%a", d0079) == "0x1.0079p+16");
+
+  // >>> hex_float_optimizes_leading_digit_bit_count. The number 1.5, when
+  // formatted by glibc should yield "0x1.8p+0" for `double` and "0xcp-3" for
+  // `long double`, i.e., number of bits in the leading digit is adapted to the
+  // number of bits in the mantissa.
+  const double d_15 = 1.5;
+  const long double ld_15 = 1.5;
+  result.hex_float_optimizes_leading_digit_bit_count =
+      StartsWith(StrPrint("%a", d_15), "0x1.8") &&
+      StartsWith(StrPrint("%La", ld_15), "0xc");
+
+  return result;
+}
+
+const NativePrintfTraits &VerifyNativeImplementation() {
+  static NativePrintfTraits native_traits = VerifyNativeImplementationImpl();
+  return native_traits;
+}
+
 class FormatConvertTest : public ::testing::Test { };
 
 template <typename T>
@@ -476,6 +541,7 @@ TEST_F(FormatConvertTest, Uint128) {
 
 template <typename Floating>
 void TestWithMultipleFormatsHelper(const std::vector<Floating> &floats) {
+  const NativePrintfTraits &native_traits = VerifyNativeImplementation();
   // Reserve the space to ensure we don't allocate memory in the output itself.
   std::string str_format_result;
   str_format_result.reserve(1 << 20);
@@ -493,13 +559,23 @@ void TestWithMultipleFormatsHelper(const std::vector<Floating> &floats) {
                    'e', 'E'}) {
       std::string fmt_str = std::string(fmt) + f;
 
-      if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F') {
+      if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F' &&
+          f != 'a' && f != 'A') {
         // This particular test takes way too long with snprintf.
         // Disable for the case we are not implementing natively.
         continue;
       }
 
+      if ((f == 'a' || f == 'A') &&
+          !native_traits.hex_float_has_glibc_rounding) {
+        continue;
+      }
+
       for (Floating d : floats) {
+        if (!native_traits.hex_float_prefers_denormal_repr &&
+            (f == 'a' || f == 'A') && std::fpclassify(d) == FP_SUBNORMAL) {
+          continue;
+        }
         int i = -10;
         FormatArgImpl args[2] = {FormatArgImpl(d), FormatArgImpl(i)};
         UntypedFormatSpecImpl format(fmt_str);
@@ -766,6 +842,111 @@ TEST_F(FormatConvertTest, DoubleRound) {
             "1837869002408041296803276054561138153076171875");
 }
 
+TEST_F(FormatConvertTest, DoubleRoundA) {
+  const NativePrintfTraits &native_traits = VerifyNativeImplementation();
+  std::string s;
+  const auto format = [&](const char *fmt, double d) -> std::string & {
+    s.clear();
+    FormatArgImpl args[1] = {FormatArgImpl(d)};
+    AppendPack(&s, UntypedFormatSpecImpl(fmt), absl::MakeSpan(args));
+    if (native_traits.hex_float_has_glibc_rounding) {
+      EXPECT_EQ(StrPrint(fmt, d), s);
+    }
+    return s;
+  };
+
+  // 0x1.00018000p+100
+  const double on_boundary_odd = 1267679614447900152596896153600.0;
+  EXPECT_EQ(format("%.0a", on_boundary_odd), "0x1p+100");
+  EXPECT_EQ(format("%.1a", on_boundary_odd), "0x1.0p+100");
+  EXPECT_EQ(format("%.2a", on_boundary_odd), "0x1.00p+100");
+  EXPECT_EQ(format("%.3a", on_boundary_odd), "0x1.000p+100");
+  EXPECT_EQ(format("%.4a", on_boundary_odd), "0x1.0002p+100");  // round
+  EXPECT_EQ(format("%.5a", on_boundary_odd), "0x1.00018p+100");
+  EXPECT_EQ(format("%.6a", on_boundary_odd), "0x1.000180p+100");
+
+  // 0x1.00028000p-2
+  const double on_boundary_even = 0.250009536743164062500;
+  EXPECT_EQ(format("%.0a", on_boundary_even), "0x1p-2");
+  EXPECT_EQ(format("%.1a", on_boundary_even), "0x1.0p-2");
+  EXPECT_EQ(format("%.2a", on_boundary_even), "0x1.00p-2");
+  EXPECT_EQ(format("%.3a", on_boundary_even), "0x1.000p-2");
+  EXPECT_EQ(format("%.4a", on_boundary_even), "0x1.0002p-2");  // no round
+  EXPECT_EQ(format("%.5a", on_boundary_even), "0x1.00028p-2");
+  EXPECT_EQ(format("%.6a", on_boundary_even), "0x1.000280p-2");
+
+  // 0x1.00018001p+1
+  const double slightly_over = 2.00004577683284878730773925781250;
+  EXPECT_EQ(format("%.0a", slightly_over), "0x1p+1");
+  EXPECT_EQ(format("%.1a", slightly_over), "0x1.0p+1");
+  EXPECT_EQ(format("%.2a", slightly_over), "0x1.00p+1");
+  EXPECT_EQ(format("%.3a", slightly_over), "0x1.000p+1");
+  EXPECT_EQ(format("%.4a", slightly_over), "0x1.0002p+1");
+  EXPECT_EQ(format("%.5a", slightly_over), "0x1.00018p+1");
+  EXPECT_EQ(format("%.6a", slightly_over), "0x1.000180p+1");
+
+  // 0x1.00017fffp+0
+  const double slightly_under = 1.000022887950763106346130371093750;
+  EXPECT_EQ(format("%.0a", slightly_under), "0x1p+0");
+  EXPECT_EQ(format("%.1a", slightly_under), "0x1.0p+0");
+  EXPECT_EQ(format("%.2a", slightly_under), "0x1.00p+0");
+  EXPECT_EQ(format("%.3a", slightly_under), "0x1.000p+0");
+  EXPECT_EQ(format("%.4a", slightly_under), "0x1.0001p+0");
+  EXPECT_EQ(format("%.5a", slightly_under), "0x1.00018p+0");
+  EXPECT_EQ(format("%.6a", slightly_under), "0x1.000180p+0");
+  EXPECT_EQ(format("%.7a", slightly_under), "0x1.0001800p+0");
+
+  // 0x1.1b3829ac28058p+3
+  const double hex_value = 8.85060580848964661981881363317370414733886718750;
+  EXPECT_EQ(format("%.0a", hex_value), "0x1p+3");
+  EXPECT_EQ(format("%.1a", hex_value), "0x1.2p+3");
+  EXPECT_EQ(format("%.2a", hex_value), "0x1.1bp+3");
+  EXPECT_EQ(format("%.3a", hex_value), "0x1.1b4p+3");
+  EXPECT_EQ(format("%.4a", hex_value), "0x1.1b38p+3");
+  EXPECT_EQ(format("%.5a", hex_value), "0x1.1b383p+3");
+  EXPECT_EQ(format("%.6a", hex_value), "0x1.1b382ap+3");
+  EXPECT_EQ(format("%.7a", hex_value), "0x1.1b3829bp+3");
+  EXPECT_EQ(format("%.8a", hex_value), "0x1.1b3829acp+3");
+  EXPECT_EQ(format("%.9a", hex_value), "0x1.1b3829ac3p+3");
+  EXPECT_EQ(format("%.10a", hex_value), "0x1.1b3829ac28p+3");
+  EXPECT_EQ(format("%.11a", hex_value), "0x1.1b3829ac280p+3");
+  EXPECT_EQ(format("%.12a", hex_value), "0x1.1b3829ac2806p+3");
+  EXPECT_EQ(format("%.13a", hex_value), "0x1.1b3829ac28058p+3");
+  EXPECT_EQ(format("%.14a", hex_value), "0x1.1b3829ac280580p+3");
+  EXPECT_EQ(format("%.15a", hex_value), "0x1.1b3829ac2805800p+3");
+  EXPECT_EQ(format("%.16a", hex_value), "0x1.1b3829ac28058000p+3");
+  EXPECT_EQ(format("%.17a", hex_value), "0x1.1b3829ac280580000p+3");
+  EXPECT_EQ(format("%.18a", hex_value), "0x1.1b3829ac2805800000p+3");
+  EXPECT_EQ(format("%.19a", hex_value), "0x1.1b3829ac28058000000p+3");
+  EXPECT_EQ(format("%.20a", hex_value), "0x1.1b3829ac280580000000p+3");
+  EXPECT_EQ(format("%.21a", hex_value), "0x1.1b3829ac2805800000000p+3");
+
+  // 0x1.0818283848586p+3
+  const double hex_value2 = 8.2529488658208371987257123691961169242858886718750;
+  EXPECT_EQ(format("%.0a", hex_value2), "0x1p+3");
+  EXPECT_EQ(format("%.1a", hex_value2), "0x1.1p+3");
+  EXPECT_EQ(format("%.2a", hex_value2), "0x1.08p+3");
+  EXPECT_EQ(format("%.3a", hex_value2), "0x1.082p+3");
+  EXPECT_EQ(format("%.4a", hex_value2), "0x1.0818p+3");
+  EXPECT_EQ(format("%.5a", hex_value2), "0x1.08183p+3");
+  EXPECT_EQ(format("%.6a", hex_value2), "0x1.081828p+3");
+  EXPECT_EQ(format("%.7a", hex_value2), "0x1.0818284p+3");
+  EXPECT_EQ(format("%.8a", hex_value2), "0x1.08182838p+3");
+  EXPECT_EQ(format("%.9a", hex_value2), "0x1.081828385p+3");
+  EXPECT_EQ(format("%.10a", hex_value2), "0x1.0818283848p+3");
+  EXPECT_EQ(format("%.11a", hex_value2), "0x1.08182838486p+3");
+  EXPECT_EQ(format("%.12a", hex_value2), "0x1.081828384858p+3");
+  EXPECT_EQ(format("%.13a", hex_value2), "0x1.0818283848586p+3");
+  EXPECT_EQ(format("%.14a", hex_value2), "0x1.08182838485860p+3");
+  EXPECT_EQ(format("%.15a", hex_value2), "0x1.081828384858600p+3");
+  EXPECT_EQ(format("%.16a", hex_value2), "0x1.0818283848586000p+3");
+  EXPECT_EQ(format("%.17a", hex_value2), "0x1.08182838485860000p+3");
+  EXPECT_EQ(format("%.18a", hex_value2), "0x1.081828384858600000p+3");
+  EXPECT_EQ(format("%.19a", hex_value2), "0x1.0818283848586000000p+3");
+  EXPECT_EQ(format("%.20a", hex_value2), "0x1.08182838485860000000p+3");
+  EXPECT_EQ(format("%.21a", hex_value2), "0x1.081828384858600000000p+3");
+}
+
 // We don't actually store the results. This is just to exercise the rest of the
 // machinery.
 struct NullSink {
@@ -797,6 +978,7 @@ TEST_F(FormatConvertTest, LongDouble) {
   // implementation against the native one there.
   return;
 #endif  // _MSC_VER
+  const NativePrintfTraits &native_traits = VerifyNativeImplementation();
   const char *const kFormats[] = {"%",    "%.3", "%8.5", "%9",  "%.5000",
                                   "%.60", "%+",  "% ",   "%-10"};
 
@@ -839,12 +1021,20 @@ TEST_F(FormatConvertTest, LongDouble) {
                    'e', 'E'}) {
       std::string fmt_str = std::string(fmt) + 'L' + f;
 
-      if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F') {
+      if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F' &&
+          f != 'a' && f != 'A') {
         // This particular test takes way too long with snprintf.
         // Disable for the case we are not implementing natively.
         continue;
       }
 
+      if (f == 'a' || f == 'A') {
+        if (!native_traits.hex_float_has_glibc_rounding ||
+            !native_traits.hex_float_optimizes_leading_digit_bit_count) {
+          continue;
+        }
+      }
+
       for (auto d : doubles) {
         FormatArgImpl arg(d);
         UntypedFormatSpecImpl format(fmt_str);
@@ -860,6 +1050,7 @@ TEST_F(FormatConvertTest, LongDouble) {
 }
 
 TEST_F(FormatConvertTest, IntAsDouble) {
+  const NativePrintfTraits &native_traits = VerifyNativeImplementation();
   const int kMin = std::numeric_limits<int>::min();
   const int kMax = std::numeric_limits<int>::max();
   const int ia[] = {
@@ -875,14 +1066,16 @@ TEST_F(FormatConvertTest, IntAsDouble) {
       const char *fmt;
     };
     const double dx = static_cast<double>(fx);
-    const Expectation kExpect[] = {
-      { __LINE__, StrPrint("%f", dx), "%f" },
-      { __LINE__, StrPrint("%12f", dx), "%12f" },
-      { __LINE__, StrPrint("%.12f", dx), "%.12f" },
-      { __LINE__, StrPrint("%12a", dx), "%12a" },
-      { __LINE__, StrPrint("%.12a", dx), "%.12a" },
+    std::vector<Expectation> expect = {
+        {__LINE__, StrPrint("%f", dx), "%f"},
+        {__LINE__, StrPrint("%12f", dx), "%12f"},
+        {__LINE__, StrPrint("%.12f", dx), "%.12f"},
+        {__LINE__, StrPrint("%.12a", dx), "%.12a"},
     };
-    for (const Expectation &e : kExpect) {
+    if (native_traits.hex_float_uses_minimal_precision_when_not_specified) {
+      expect.push_back({__LINE__, StrPrint("%12a", dx), "%12a"});
+    }
+    for (const Expectation &e : expect) {
       SCOPED_TRACE(e.line);
       SCOPED_TRACE(e.fmt);
       UntypedFormatSpecImpl format(e.fmt);
@@ -927,6 +1120,25 @@ TEST_F(FormatConvertTest, ExpectedFailures) {
   EXPECT_TRUE(FormatFails("%*d", ""));
 }
 
+// Sanity check to make sure that we are testing what we think we're testing on
+// e.g. the x86_64+glibc platform.
+TEST_F(FormatConvertTest, GlibcHasCorrectTraits) {
+#if !defined(__GLIBC__) || !defined(__x86_64__)
+  return;
+#endif
+  const NativePrintfTraits &native_traits = VerifyNativeImplementation();
+  // If one of the following tests break then it is either because the above PP
+  // macro guards failed to exclude a new platform (likely) or because something
+  // has changed in the implemention of glibc sprintf float formatting behavior.
+  // If the latter, then the code that computes these flags needs to be
+  // revisited and/or possibly the StrFormat implementation.
+  EXPECT_TRUE(native_traits.hex_float_has_glibc_rounding);
+  EXPECT_TRUE(native_traits.hex_float_prefers_denormal_repr);
+  EXPECT_TRUE(
+      native_traits.hex_float_uses_minimal_precision_when_not_specified);
+  EXPECT_TRUE(native_traits.hex_float_optimizes_leading_digit_bit_count);
+}
+
 }  // namespace
 }  // namespace str_format_internal
 ABSL_NAMESPACE_END