Export of internal Abseil changes

--
167cd2647144583746311129b0cc98a89a9897e1 by Andy Soffer <asoffer@google.com>:

Internal Changes

PiperOrigin-RevId: 268000987

--
ab44fea7dfdaf763c69609a08ddfac22480ce520 by Derek Mauro <dmauro@google.com>:

Fix flags Cmake tests on Windows

PiperOrigin-RevId: 267859442

--
d7ec9f7611370b01bc9a5aed7e18460df2a15429 by Abseil Team <absl-team@google.com>:

Fix undefined behavior in symbolize_elf.inc

PiperOrigin-RevId: 267684904

--
e7c5f8e472a91ed99bdf4876942f2bda5751aa6c by Abseil Team <absl-team@google.com>:

Turn off ABSL_HAS_ALARM on Fuchsia.

PiperOrigin-RevId: 267666090

--
b7d25d5c71a49e697a8bf6440ed30f2e3f036420 by Chris Kennelly <ckennelly@google.com>:

Mark once initialization function as no inline.

We expect this code to run infrequently.

PiperOrigin-RevId: 267649713

--
dc2a5e5f1e39a03fff837d34a319033fde55d9ba by Derek Mauro <dmauro@google.com>:

Fix the MSVC CMake random build

PiperOrigin-RevId: 267624074

--
ba2751b67fa17d1b6c53e5ba79f81a5371e4a03a by Abseil Team <absl-team@google.com>:

Move "internal/flag.*" files to the "internal" build target.

PiperOrigin-RevId: 267588996

--
05b985a33eec4f8acff1809ad9218a1e22220f34 by Abseil Team <absl-team@google.com>:

Move "internal/flag.*" files to the "internal" build target.

PiperOrigin-RevId: 267580412
GitOrigin-RevId: 167cd2647144583746311129b0cc98a89a9897e1
Change-Id: Ibd334f46a5671c7c1d3fcf5354029e2fbb7ba91f

absl/base/call_once.h

@@ -142,6 +142,7 @@ enum {
 };
 
 template <typename Callable, typename... Args>
+ABSL_ATTRIBUTE_NOINLINE
 void CallOnceImpl(std::atomic<uint32_t>* control,
                   base_internal::SchedulingMode scheduling_mode, Callable&& fn,
                   Args&&... args) {

absl/base/config.h

@@ -336,6 +336,8 @@
 // feature tests for Microsoft's library
 #elif defined(__EMSCRIPTEN__)
 // emscripten doesn't support signals
+#elif defined(__Fuchsia__)
+// Signals don't exist on fuchsia.
 #elif defined(__native_client__)
 #else
 // other standard libraries

absl/debugging/symbolize_elf.inc

@@ -624,6 +624,13 @@ static bool InSection(const void *address, const ElfW(Shdr) * section) {
   return start <= address && address < (start + size);
 }
 
+static const char *ComputeOffset(const char *base, ptrdiff_t offset) {
+  // Note: cast to uintptr_t to avoid undefined behavior when base evaluates to
+  // zero and offset is non-zero.
+  return reinterpret_cast<const char *>(
+      reinterpret_cast<uintptr_t>(base) + offset);
+}
+
 // Read a symbol table and look for the symbol containing the
 // pc. Iterate over symbols in a symbol table and look for the symbol
 // containing "pc".  If the symbol is found, and its name fits in
@@ -676,7 +683,8 @@ static ABSL_ATTRIBUTE_NOINLINE FindSymbolResult FindSymbol(
       // We keep the original address for opd redirection below.
       const char *const original_start_address =
           reinterpret_cast<const char *>(symbol.st_value);
-      const char *start_address = original_start_address + relocation;
+      const char *start_address =
+          ComputeOffset(original_start_address, relocation);
 
       if (deref_function_descriptor_pointer &&
           InSection(original_start_address, opd)) {
@@ -688,8 +696,7 @@ static ABSL_ATTRIBUTE_NOINLINE FindSymbolResult FindSymbol(
 
       // If pc is inside the .opd section, it points to a function descriptor.
       const size_t size = pc_in_opd ? kFunctionDescriptorSize : symbol.st_size;
-      const void *const end_address =
+      const void *const end_address = ComputeOffset(start_address, size);
-          reinterpret_cast<const char *>(start_address) + size;
       if (symbol.st_value != 0 &&  // Skip null value symbols.
           symbol.st_shndx != 0 &&  // Skip undefined symbols.
 #ifdef STT_TLS

absl/flags/BUILD.bazel

@@ -231,6 +231,7 @@ cc_test(
     copts = ABSL_TEST_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
+        ":config",
         ":flag",
         ":handle",
         ":registry",
@@ -264,6 +265,7 @@ cc_test(
     copts = ABSL_TEST_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
+        ":config",
         ":flag",
         "//absl/strings",
         "@com_google_googletest//:gtest_main",

absl/flags/CMakeLists.txt

@@ -213,6 +213,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::flags
+    absl::flags_config
     absl::flags_handle
     absl::flags_registry
     absl::memory
@@ -242,6 +243,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::flags
+    absl::flags_config
     absl::strings
     gtest_main
 )

absl/flags/flag_test.cc

@@ -15,7 +15,11 @@
 
 #include "absl/flags/flag.h"
 
+#include <algorithm>
+#include <string>
+
 #include "gtest/gtest.h"
+#include "absl/flags/usage_config.h"
 #include "absl/strings/match.h"
 #include "absl/strings/numbers.h"
 #include "absl/strings/str_cat.h"
@@ -63,7 +67,27 @@ struct UDT {
 bool AbslParseFlag(absl::string_view, UDT*, std::string*) { return true; }
 std::string AbslUnparseFlag(const UDT&) { return ""; }
 
-TEST(FlagTest, TestConstruction) {
+class FlagTest : public testing::Test {
+ protected:
+  static void SetUpTestSuite() {
+    // Install a function to normalize filenames before this test is run.
+    absl::FlagsUsageConfig default_config;
+    default_config.normalize_filename = &FlagTest::NormalizeFileName;
+    absl::SetFlagsUsageConfig(default_config);
+  }
+
+ private:
+  static std::string NormalizeFileName(absl::string_view fname) {
+#ifdef _WIN32
+    std::string normalized(fname);
+    std::replace(normalized.begin(), normalized.end(), '\\', '/');
+    fname = normalized;
+#endif
+    return std::string(fname);
+  }
+};
+
+TEST_F(FlagTest, TestConstruction) {
   TestConstructionFor<bool>();
   TestConstructionFor<int16_t>();
   TestConstructionFor<uint16_t>();
@@ -98,7 +122,7 @@ namespace {
 
 #if !ABSL_FLAGS_STRIP_NAMES
 
-TEST(FlagTest, TestFlagDeclaration) {
+TEST_F(FlagTest, TestFlagDeclaration) {
   // test that we can access flag objects.
   EXPECT_EQ(FLAGS_test_flag_01.Name(), "test_flag_01");
   EXPECT_EQ(FLAGS_test_flag_02.Name(), "test_flag_02");
@@ -133,69 +157,69 @@ ABSL_FLAG(std::string, test_flag_11, "", "test flag 11");
 namespace {
 
 #if !ABSL_FLAGS_STRIP_NAMES
-TEST(FlagTest, TestFlagDefinition) {
+TEST_F(FlagTest, TestFlagDefinition) {
   absl::string_view expected_file_name = "absl/flags/flag_test.cc";
 
   EXPECT_EQ(FLAGS_test_flag_01.Name(), "test_flag_01");
   EXPECT_EQ(FLAGS_test_flag_01.Help(), "test flag 01");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_01.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_01.Filename(), expected_file_name));
+      << FLAGS_test_flag_01.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_02.Name(), "test_flag_02");
   EXPECT_EQ(FLAGS_test_flag_02.Help(), "test flag 02");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_02.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_02.Filename(), expected_file_name));
+      << FLAGS_test_flag_02.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_03.Name(), "test_flag_03");
   EXPECT_EQ(FLAGS_test_flag_03.Help(), "test flag 03");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_03.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_03.Filename(), expected_file_name));
+      << FLAGS_test_flag_03.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_04.Name(), "test_flag_04");
   EXPECT_EQ(FLAGS_test_flag_04.Help(), "test flag 04");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_04.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_04.Filename(), expected_file_name));
+      << FLAGS_test_flag_04.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_05.Name(), "test_flag_05");
   EXPECT_EQ(FLAGS_test_flag_05.Help(), "test flag 05");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_05.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_05.Filename(), expected_file_name));
+      << FLAGS_test_flag_05.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_06.Name(), "test_flag_06");
   EXPECT_EQ(FLAGS_test_flag_06.Help(), "test flag 06");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_06.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_06.Filename(), expected_file_name));
+      << FLAGS_test_flag_06.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_07.Name(), "test_flag_07");
   EXPECT_EQ(FLAGS_test_flag_07.Help(), "test flag 07");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_07.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_07.Filename(), expected_file_name));
+      << FLAGS_test_flag_07.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_08.Name(), "test_flag_08");
   EXPECT_EQ(FLAGS_test_flag_08.Help(), "test flag 08");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_08.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_08.Filename(), expected_file_name));
+      << FLAGS_test_flag_08.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_09.Name(), "test_flag_09");
   EXPECT_EQ(FLAGS_test_flag_09.Help(), "test flag 09");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_09.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_09.Filename(), expected_file_name));
+      << FLAGS_test_flag_09.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_10.Name(), "test_flag_10");
   EXPECT_EQ(FLAGS_test_flag_10.Help(), "test flag 10");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_10.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_10.Filename(), expected_file_name));
+      << FLAGS_test_flag_10.Filename();
 
   EXPECT_EQ(FLAGS_test_flag_11.Name(), "test_flag_11");
   EXPECT_EQ(FLAGS_test_flag_11.Help(), "test flag 11");
-  EXPECT_TRUE(
+  EXPECT_TRUE(absl::EndsWith(FLAGS_test_flag_11.Filename(), expected_file_name))
-      absl::EndsWith(FLAGS_test_flag_11.Filename(), expected_file_name));
+      << FLAGS_test_flag_11.Filename();
 }
 #endif  // !ABSL_FLAGS_STRIP_NAMES
 
 // --------------------------------------------------------------------
 
-TEST(FlagTest, TestDefault) {
+TEST_F(FlagTest, TestDefault) {
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_01), true);
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_02), 1234);
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_03), -34);
@@ -211,7 +235,7 @@ TEST(FlagTest, TestDefault) {
 
 // --------------------------------------------------------------------
 
-TEST(FlagTest, TestGetSet) {
+TEST_F(FlagTest, TestGetSet) {
   absl::SetFlag(&FLAGS_test_flag_01, false);
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_01), false);
 
@@ -258,7 +282,7 @@ ABSL_FLAG(std::string, test_flag_13, absl::StrCat("AAA", "BBB"),
 
 namespace {
 
-TEST(FlagTest, TestNonConstexprDefault) {
+TEST_F(FlagTest, TestNonConstexprDefault) {
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_12), 1);
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_13), "AAABBB");
 }
@@ -272,7 +296,7 @@ ABSL_FLAG(bool, test_flag_14, true, absl::StrCat("test ", "flag ", "14"));
 namespace {
 
 #if !ABSL_FLAGS_STRIP_HELP
-TEST(FlagTest, TestNonConstexprHelp) {
+TEST_F(FlagTest, TestNonConstexprHelp) {
   EXPECT_EQ(FLAGS_test_flag_14.Help(), "test flag 14");
 }
 #endif  //! ABSL_FLAGS_STRIP_HELP
@@ -296,7 +320,7 @@ namespace {
 void TestFlagCB() { cb_test_value = absl::GetFlag(FLAGS_test_flag_with_cb); }
 
 // Tests side-effects of callback invocation.
-TEST(FlagTest, CallbackInvocation) {
+TEST_F(FlagTest, CallbackInvocation) {
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_with_cb), 100);
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_with_lambda_cb), 200);
   EXPECT_EQ(cb_test_value, 300);
@@ -343,7 +367,7 @@ ABSL_FLAG(CustomUDT, test_flag_15, CustomUDT(), "test flag 15");
 
 namespace {
 
-TEST(FlagTest, TestCustomUDT) {
+TEST_F(FlagTest, TestCustomUDT) {
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_15), CustomUDT(1, 1));
   absl::SetFlag(&FLAGS_test_flag_15, CustomUDT(2, 3));
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_15), CustomUDT(2, 3));
@@ -409,7 +433,7 @@ ABSL_FLAG(ConversionTestVal, test_flag_16,
 
 namespace {
 
-TEST(FlagTest, CanSetViaImplicitConversion) {
+TEST_F(FlagTest, CanSetViaImplicitConversion) {
   EXPECT_EQ(absl::GetFlag(FLAGS_test_flag_16).a, 10);
   absl::SetFlag(&FLAGS_test_flag_16,
                 ConversionTestVal::ViaImplicitConv::kEleven);
@@ -447,7 +471,7 @@ ABSL_FLAG(NonDfltConstructible, ndc_flag2, 0,
 
 namespace {
 
-TEST(FlagTest, TestNonDefaultConstructibleType) {
+TEST_F(FlagTest, TestNonDefaultConstructibleType) {
   EXPECT_EQ(absl::GetFlag(FLAGS_ndc_flag1).value, '1' + 100);
   EXPECT_EQ(absl::GetFlag(FLAGS_ndc_flag2).value, 0);
 
@@ -468,7 +492,7 @@ ABSL_RETIRED_FLAG(std::string, old_str_flag, "", absl::StrCat("old ", "descr"));
 
 namespace {
 
-TEST(FlagTest, TestRetiredFlagRegistration) {
+TEST_F(FlagTest, TestRetiredFlagRegistration) {
   bool is_bool = false;
   EXPECT_TRUE(flags::IsRetiredFlag("old_bool_flag", &is_bool));
   EXPECT_TRUE(is_bool);

absl/flags/internal/commandlineflag_test.cc

@@ -15,9 +15,13 @@
 
 #include "absl/flags/internal/commandlineflag.h"
 
+#include <algorithm>
+#include <string>
+
 #include "gtest/gtest.h"
 #include "absl/flags/flag.h"
 #include "absl/flags/internal/registry.h"
+#include "absl/flags/usage_config.h"
 #include "absl/memory/memory.h"
 #include "absl/strings/match.h"
 #include "absl/strings/str_cat.h"
@@ -33,10 +37,26 @@ namespace flags = absl::flags_internal;
 
 class CommandLineFlagTest : public testing::Test {
  protected:
+  static void SetUpTestSuite() {
+    // Install a function to normalize filenames before this test is run.
+    absl::FlagsUsageConfig default_config;
+    default_config.normalize_filename = &CommandLineFlagTest::NormalizeFileName;
+    absl::SetFlagsUsageConfig(default_config);
+  }
+
   void SetUp() override { flag_saver_ = absl::make_unique<flags::FlagSaver>(); }
   void TearDown() override { flag_saver_.reset(); }
 
  private:
+  static std::string NormalizeFileName(absl::string_view fname) {
+#ifdef _WIN32
+    std::string normalized(fname);
+    std::replace(normalized.begin(), normalized.end(), '\\', '/');
+    fname = normalized;
+#endif
+    return std::string(fname);
+  }
+
   std::unique_ptr<flags::FlagSaver> flag_saver_;
 };
 
@@ -49,9 +69,10 @@ TEST_F(CommandLineFlagTest, TestAttributesAccessMethods) {
   EXPECT_EQ(flag_01->Typename(), "");
   EXPECT_TRUE(!flag_01->IsRetired());
   EXPECT_TRUE(flag_01->IsOfType<int>());
-  EXPECT_TRUE(absl::EndsWith(
+  EXPECT_TRUE(
-      flag_01->Filename(),
+      absl::EndsWith(flag_01->Filename(),
-      "absl/flags/internal/commandlineflag_test.cc"));
+                     "absl/flags/internal/commandlineflag_test.cc"))
+      << flag_01->Filename();
 
   auto* flag_02 = flags::FindCommandLineFlag("string_flag");
 
@@ -61,9 +82,10 @@ TEST_F(CommandLineFlagTest, TestAttributesAccessMethods) {
   EXPECT_EQ(flag_02->Typename(), "");
   EXPECT_TRUE(!flag_02->IsRetired());
   EXPECT_TRUE(flag_02->IsOfType<std::string>());
-  EXPECT_TRUE(absl::EndsWith(
+  EXPECT_TRUE(
-      flag_02->Filename(),
+      absl::EndsWith(flag_02->Filename(),
-      "absl/flags/internal/commandlineflag_test.cc"));
+                     "absl/flags/internal/commandlineflag_test.cc"))
+      << flag_02->Filename();
 
   auto* flag_03 = flags::FindRetiredFlag("bool_retired_flag");
 

absl/flags/internal/usage_test.cc

@@ -67,9 +67,9 @@ static std::string NormalizeFileName(absl::string_view fname) {
   fname = normalized;
 #endif
 
-  auto absl_pos = fname.find("/absl/");
+  auto absl_pos = fname.rfind("absl/");
   if (absl_pos != absl::string_view::npos) {
-    fname = fname.substr(absl_pos + 1);
+    fname = fname.substr(absl_pos);
   }
   return std::string(fname);
 }

absl/random/CMakeLists.txt

@@ -1025,6 +1025,8 @@ absl_cc_test(
     random_internal_iostream_state_saver_test
   SRCS
     "internal/iostream_state_saver_test.cc"
+  COPTS
+    ${ABSL_TEST_COPTS}
   LINKOPTS
     ${ABSL_DEFAULT_LINKOPTS}
   DEPS

absl/random/beta_distribution.h

@@ -129,7 +129,7 @@ class beta_distribution {
    private:
     friend class beta_distribution;
 
-#ifdef COMPILER_MSVC
+#ifdef _MSC_VER
     // MSVC does not have constexpr implementations for std::log and std::exp
     // so they are computed at runtime.
 #define ABSL_RANDOM_INTERNAL_LOG_EXP_CONSTEXPR

absl/random/distribution_format_traits.h

@@ -36,6 +36,12 @@
 #include "absl/types/span.h"
 
 namespace absl {
+
+struct IntervalClosedClosedTag;
+struct IntervalClosedOpenTag;
+struct IntervalOpenClosedTag;
+struct IntervalOpenOpenTag;
+
 namespace random_internal {
 
 // ScalarTypeName defines a preferred hierarchy of preferred type names for
@@ -243,6 +249,39 @@ struct DistributionFormatTraits<absl::log_uniform_int_distribution<R>> {
   }
 };
 
+template <typename TagType, typename NumType>
+struct UniformDistributionWrapper;
+
+template <typename TagType, typename NumType>
+struct DistributionFormatTraits<UniformDistributionWrapper<TagType, NumType>> {
+  using distribution_t = UniformDistributionWrapper<TagType, NumType>;
+  using result_t = NumType;
+
+  static constexpr const char* Name() { return "Uniform"; }
+
+  static std::string FunctionName() {
+    return absl::StrCat(Name(), "<", ScalarTypeName<NumType>(), ">");
+  }
+  static std::string FormatArgs(const distribution_t& d) {
+    absl::string_view tag;
+    if (std::is_same<TagType, IntervalClosedClosedTag>::value) {
+      tag = "IntervalClosedClosed";
+    } else if (std::is_same<TagType, IntervalClosedOpenTag>::value) {
+      tag = "IntervalClosedOpen";
+    } else if (std::is_same<TagType, IntervalOpenClosedTag>::value) {
+      tag = "IntervalOpenClosed";
+    } else if (std::is_same<TagType, IntervalOpenOpenTag>::value) {
+      tag = "IntervalOpenOpen";
+    } else {
+      tag = "[[unknown tag type]]";
+    }
+    return absl::StrCat(tag, ", ", (d.min)(), ", ", (d.max)());
+  }
+  static std::string FormatResults(absl::Span<const result_t> results) {
+    return absl::StrJoin(results, ", ");
+  }
+};
+
 }  // namespace random_internal
 }  // namespace absl
 

absl/random/internal/BUILD.bazel

@@ -60,13 +60,11 @@ cc_library(
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
         ":distribution_caller",
-        ":fast_uniform_bits",
-        ":fastmath",
         ":traits",
         ":uniform_helper",
+        "//absl/base",
         "//absl/meta:type_traits",
         "//absl/strings",
-        "//absl/types:span",
     ],
 )
 
@@ -618,11 +616,6 @@ cc_library(
     copts = ABSL_DEFAULT_COPTS,
     linkopts = ABSL_DEFAULT_LINKOPTS,
     deps = [
-        ":distribution_impl",
-        ":fast_uniform_bits",
-        ":iostream_state_saver",
-        ":traits",
-        "//absl/base:core_headers",
         "//absl/meta:type_traits",
     ],
 )

absl/random/internal/distributions.h

@@ -39,22 +39,20 @@ NumType UniformImpl(TagType tag,
       "absl::Uniform<T>() must use an integer or real parameter type.");
 
   using distribution_t =
-      typename std::conditional<std::is_integral<NumType>::value,
+      UniformDistributionWrapper<absl::decay_t<TagType>, NumType>;
-                                absl::uniform_int_distribution<NumType>,
-                                absl::uniform_real_distribution<NumType>>::type;
   using format_t = random_internal::DistributionFormatTraits<distribution_t>;
+  auto a = uniform_lower_bound(tag, lo, hi);
+  auto b = uniform_upper_bound(tag, lo, hi);
 
-  auto a = random_internal::uniform_lower_bound<NumType>(tag, lo, hi);
-  auto b = random_internal::uniform_upper_bound<NumType>(tag, lo, hi);
   // TODO(lar): it doesn't make a lot of sense to ask for a random number in an
   // empty range.  Right now we just return a boundary--even though that
   // boundary is not an acceptable value!  Is there something better we can do
   // here?
+  if (a > b) return a;
 
   using gen_t = absl::decay_t<URBG>;
-  if (a > b) return a;
   return DistributionCaller<gen_t>::template Call<distribution_t, format_t>(
-      &urbg, a, b);
+      &urbg, tag, lo, hi);
 }
 
 // In the absence of an explicitly provided return-type, the template

absl/random/internal/uniform_helper.h

@@ -156,7 +156,7 @@ using UniformDistribution =
 
 template <typename TagType, typename NumType>
 struct UniformDistributionWrapper : public UniformDistribution<NumType> {
-  explicit UniformDistributionWrapper(NumType lo, NumType hi)
+  explicit UniformDistributionWrapper(TagType, NumType lo, NumType hi)
       : UniformDistribution<NumType>(
             uniform_lower_bound<NumType>(TagType{}, lo, hi),
             uniform_upper_bound<NumType>(TagType{}, lo, hi)) {}