Export of internal Abseil changes
--
1609589925459c2c0b2a17912c0d65227f709db9 by Abseil Team <absl-team@google.com>:
Clarify the "Potential Mutex deadlock" reason message.
PiperOrigin-RevId: 351367862
--
88bf28863db2c2d2d48767c3e4dfab6a48bdff79 by Abseil Team <absl-team@google.com>:
Print CPU number is fault handler.
This CL adds code to print CPU number inside the fault handler. This is only supported on Linux. The CPU number is also a hint only. There is no guarantee that it is indeed the CPU on which a fault happened.
PiperOrigin-RevId: 351238373
--
66a9c8e44b5744fec1ca0d7b8db7e1d50772d9a2 by Samuel Benzaquen <sbenza@google.com>:
Add better error message for ODR violations of flags.
PiperOrigin-RevId: 351197423
--
6efd1efb341563148dd43255aaa4bf959dfd9554 by Chris Kennelly <ckennelly@google.com>:
Assume bitwise builtins are available on GCC.
These are long-standing builtins but are not consistently detected by
ABSL_HAVE_BUILTIN.
PiperOrigin-RevId: 350814036
GitOrigin-RevId: 1609589925459c2c0b2a17912c0d65227f709db9
Change-Id: Ied3fd2f135187f2c316b403fba45f3bbaea54138
diff --git a/absl/base/config.h b/absl/base/config.h
index c9a06f1..f6ddf0c 100644
--- a/absl/base/config.h
+++ b/absl/base/config.h
@@ -379,6 +379,15 @@
#define ABSL_HAVE_PTHREAD_GETSCHEDPARAM 1
#endif
+// ABSL_HAVE_SCHED_GETCPU
+//
+// Checks whether sched_getcpu is available.
+#ifdef ABSL_HAVE_SCHED_GETCPU
+#error ABSL_HAVE_SCHED_GETCPU cannot be directly set
+#elif defined(__linux__)
+#define ABSL_HAVE_SCHED_GETCPU 1
+#endif
+
// ABSL_HAVE_SCHED_YIELD
//
// Checks whether the platform implements sched_yield(2) as defined in
diff --git a/absl/debugging/failure_signal_handler.cc b/absl/debugging/failure_signal_handler.cc
index 5d13bdb..a9ed6ef 100644
--- a/absl/debugging/failure_signal_handler.cc
+++ b/absl/debugging/failure_signal_handler.cc
@@ -21,6 +21,7 @@
#ifdef _WIN32
#include <windows.h>
#else
+#include <sched.h>
#include <unistd.h>
#endif
@@ -219,17 +220,24 @@
absl::raw_logging_internal::SafeWriteToStderr(data, strlen(data));
}
-static void WriteSignalMessage(int signo, void (*writerfn)(const char*)) {
- char buf[64];
+static void WriteSignalMessage(int signo, int cpu,
+ void (*writerfn)(const char*)) {
+ char buf[96];
+ char on_cpu[32] = {0};
+ if (cpu != -1) {
+ snprintf(on_cpu, sizeof(on_cpu), " on cpu %d", cpu);
+ }
const char* const signal_string =
debugging_internal::FailureSignalToString(signo);
if (signal_string != nullptr && signal_string[0] != '\0') {
- snprintf(buf, sizeof(buf), "*** %s received at time=%ld ***\n",
+ snprintf(buf, sizeof(buf), "*** %s received at time=%ld%s ***\n",
signal_string,
- static_cast<long>(time(nullptr))); // NOLINT(runtime/int)
+ static_cast<long>(time(nullptr)), // NOLINT(runtime/int)
+ on_cpu);
} else {
- snprintf(buf, sizeof(buf), "*** Signal %d received at time=%ld ***\n",
- signo, static_cast<long>(time(nullptr))); // NOLINT(runtime/int)
+ snprintf(buf, sizeof(buf), "*** Signal %d received at time=%ld%s ***\n",
+ signo, static_cast<long>(time(nullptr)), // NOLINT(runtime/int)
+ on_cpu);
}
writerfn(buf);
}
@@ -269,10 +277,10 @@
// Called by AbslFailureSignalHandler() to write the failure info. It is
// called once with writerfn set to WriteToStderr() and then possibly
// with writerfn set to the user provided function.
-static void WriteFailureInfo(int signo, void* ucontext,
+static void WriteFailureInfo(int signo, void* ucontext, int cpu,
void (*writerfn)(const char*)) {
WriterFnStruct writerfn_struct{writerfn};
- WriteSignalMessage(signo, writerfn);
+ WriteSignalMessage(signo, cpu, writerfn);
WriteStackTrace(ucontext, fsh_options.symbolize_stacktrace, WriterFnWrapper,
&writerfn_struct);
}
@@ -334,6 +342,14 @@
}
}
+ // Increase the chance that the CPU we report was the same CPU on which the
+ // signal was received by doing this as early as possible, i.e. after
+ // verifying that this is not a recursive signal handler invocation.
+ int my_cpu = -1;
+#ifdef ABSL_HAVE_SCHED_GETCPU
+ my_cpu = sched_getcpu();
+#endif
+
#ifdef ABSL_HAVE_ALARM
// Set an alarm to abort the program in case this code hangs or deadlocks.
if (fsh_options.alarm_on_failure_secs > 0) {
@@ -344,12 +360,12 @@
#endif
// First write to stderr.
- WriteFailureInfo(signo, ucontext, WriteToStderr);
+ WriteFailureInfo(signo, ucontext, my_cpu, WriteToStderr);
// Riskier code (because it is less likely to be async-signal-safe)
// goes after this point.
if (fsh_options.writerfn != nullptr) {
- WriteFailureInfo(signo, ucontext, fsh_options.writerfn);
+ WriteFailureInfo(signo, ucontext, my_cpu, fsh_options.writerfn);
}
if (fsh_options.call_previous_handler) {
diff --git a/absl/debugging/failure_signal_handler_test.cc b/absl/debugging/failure_signal_handler_test.cc
index d8283b2..6a62428 100644
--- a/absl/debugging/failure_signal_handler_test.cc
+++ b/absl/debugging/failure_signal_handler_test.cc
@@ -122,6 +122,12 @@
"*** ", absl::debugging_internal::FailureSignalToString(signo),
" received at ")));
+ // On platforms where it is possible to get the current CPU, the
+ // CPU number is also logged. Check that it is present in output.
+#if defined(__linux__)
+ EXPECT_THAT(error_line, testing::HasSubstr(" on cpu "));
+#endif
+
if (absl::debugging_internal::StackTraceWorksForTest()) {
std::getline(error_output, error_line);
EXPECT_THAT(error_line, StartsWith("PC: "));
diff --git a/absl/flags/flag.h b/absl/flags/flag.h
index a9cb2b7..f09580b 100644
--- a/absl/flags/flag.h
+++ b/absl/flags/flag.h
@@ -301,13 +301,15 @@
#if ABSL_FLAGS_STRIP_NAMES
#define ABSL_FLAG_IMPL_FLAGNAME(txt) ""
#define ABSL_FLAG_IMPL_FILENAME() ""
-#define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \
- absl::flags_internal::FlagRegistrar<T, false>(ABSL_FLAG_IMPL_FLAG_PTR(flag))
+#define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \
+ absl::flags_internal::FlagRegistrar<T, false>(ABSL_FLAG_IMPL_FLAG_PTR(flag), \
+ nullptr)
#else
#define ABSL_FLAG_IMPL_FLAGNAME(txt) txt
#define ABSL_FLAG_IMPL_FILENAME() __FILE__
-#define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \
- absl::flags_internal::FlagRegistrar<T, true>(ABSL_FLAG_IMPL_FLAG_PTR(flag))
+#define ABSL_FLAG_IMPL_REGISTRAR(T, flag) \
+ absl::flags_internal::FlagRegistrar<T, true>(ABSL_FLAG_IMPL_FLAG_PTR(flag), \
+ __FILE__)
#endif
// ABSL_FLAG_IMPL macro definition conditional on ABSL_FLAGS_STRIP_HELP
diff --git a/absl/flags/flag_test.cc b/absl/flags/flag_test.cc
index 72507b9..6912b54 100644
--- a/absl/flags/flag_test.cc
+++ b/absl/flags/flag_test.cc
@@ -177,7 +177,7 @@
EXPECT_EQ(absl::GetFlagReflectionHandle(f1).Help(), "literal help");
EXPECT_EQ(absl::GetFlagReflectionHandle(f1).Filename(), "file");
- flags::FlagRegistrar<T, false>(ABSL_FLAG_IMPL_FLAG_PTR(f2))
+ flags::FlagRegistrar<T, false>(ABSL_FLAG_IMPL_FLAG_PTR(f2), nullptr)
.OnUpdate(TestCallback);
EXPECT_EQ(absl::GetFlagReflectionHandle(f2).Name(), "f2");
diff --git a/absl/flags/internal/flag.h b/absl/flags/internal/flag.h
index 8354814..e6bade0 100644
--- a/absl/flags/internal/flag.h
+++ b/absl/flags/internal/flag.h
@@ -721,8 +721,9 @@
template <typename T, bool do_register>
class FlagRegistrar {
public:
- explicit FlagRegistrar(Flag<T>& flag) : flag_(flag) {
- if (do_register) flags_internal::RegisterCommandLineFlag(flag_.impl_);
+ explicit FlagRegistrar(Flag<T>& flag, const char* filename) : flag_(flag) {
+ if (do_register)
+ flags_internal::RegisterCommandLineFlag(flag_.impl_, filename);
}
FlagRegistrar OnUpdate(FlagCallbackFunc cb) && {
diff --git a/absl/flags/internal/registry.h b/absl/flags/internal/registry.h
index a8d9eb9..4b68c85 100644
--- a/absl/flags/internal/registry.h
+++ b/absl/flags/internal/registry.h
@@ -36,7 +36,7 @@
//-----------------------------------------------------------------------------
-bool RegisterCommandLineFlag(CommandLineFlag&);
+bool RegisterCommandLineFlag(CommandLineFlag&, const char* filename);
void FinalizeRegistry();
diff --git a/absl/flags/reflection.cc b/absl/flags/reflection.cc
index c976d46..0c76110 100644
--- a/absl/flags/reflection.cc
+++ b/absl/flags/reflection.cc
@@ -50,7 +50,7 @@
~FlagRegistry() = default;
// Store a flag in this registry. Takes ownership of *flag.
- void RegisterFlag(CommandLineFlag& flag);
+ void RegisterFlag(CommandLineFlag& flag, const char* filename);
void Lock() ABSL_EXCLUSIVE_LOCK_FUNCTION(lock_) { lock_.Lock(); }
void Unlock() ABSL_UNLOCK_FUNCTION(lock_) { lock_.Unlock(); }
@@ -110,7 +110,20 @@
return it != flags_.end() ? it->second : nullptr;
}
-void FlagRegistry::RegisterFlag(CommandLineFlag& flag) {
+void FlagRegistry::RegisterFlag(CommandLineFlag& flag, const char* filename) {
+ if (filename != nullptr &&
+ flag.Filename() != GetUsageConfig().normalize_filename(filename)) {
+ flags_internal::ReportUsageError(
+ absl::StrCat(
+ "Inconsistency between flag object and registration for flag '",
+ flag.Name(),
+ "', likely due to duplicate flags or an ODR violation. Relevant "
+ "files: ",
+ flag.Filename(), " and ", filename),
+ true);
+ std::exit(1);
+ }
+
FlagRegistryLock registry_lock(*this);
std::pair<FlagIterator, bool> ins =
@@ -175,8 +188,8 @@
// --------------------------------------------------------------------
-bool RegisterCommandLineFlag(CommandLineFlag& flag) {
- FlagRegistry::GlobalRegistry().RegisterFlag(flag);
+bool RegisterCommandLineFlag(CommandLineFlag& flag, const char* filename) {
+ FlagRegistry::GlobalRegistry().RegisterFlag(flag, filename);
return true;
}
@@ -266,7 +279,7 @@
static_assert(alignof(RetiredFlagObj) == kRetiredFlagObjAlignment, "");
auto* flag = ::new (static_cast<void*>(buf))
flags_internal::RetiredFlagObj(name, type_id);
- FlagRegistry::GlobalRegistry().RegisterFlag(*flag);
+ FlagRegistry::GlobalRegistry().RegisterFlag(*flag, nullptr);
}
// --------------------------------------------------------------------
diff --git a/absl/numeric/bits_test.cc b/absl/numeric/bits_test.cc
index 8bf7bc9..7c942aa 100644
--- a/absl/numeric/bits_test.cc
+++ b/absl/numeric/bits_test.cc
@@ -560,6 +560,14 @@
}
}
+// On GCC and Clang, anticiapte that implementations will be constexpr
+#if defined(__GNUC__)
+static_assert(ABSL_INTERNAL_HAS_CONSTEXPR_POPCOUNT,
+ "popcount should be constexpr");
+static_assert(ABSL_INTERNAL_HAS_CONSTEXPR_CLZ, "clz should be constexpr");
+static_assert(ABSL_INTERNAL_HAS_CONSTEXPR_CTZ, "ctz should be constexpr");
+#endif
+
} // namespace
ABSL_NAMESPACE_END
} // namespace absl
diff --git a/absl/numeric/internal/bits.h b/absl/numeric/internal/bits.h
index af45700..e51941d 100644
--- a/absl/numeric/internal/bits.h
+++ b/absl/numeric/internal/bits.h
@@ -28,8 +28,15 @@
#include "absl/base/attributes.h"
#include "absl/base/config.h"
-#if ABSL_HAVE_BUILTIN(__builtin_popcountl) && \
- ABSL_HAVE_BUILTIN(__builtin_popcountll)
+#if defined(__GNUC__) && !defined(__clang__)
+// GCC
+#define ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(x) 1
+#else
+#define ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(x) ABSL_HAVE_BUILTIN(x)
+#endif
+
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_popcountl) && \
+ ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_popcountll)
#define ABSL_INTERNAL_CONSTEXPR_POPCOUNT constexpr
#define ABSL_INTERNAL_HAS_CONSTEXPR_POPCOUNT 1
#else
@@ -37,7 +44,8 @@
#define ABSL_INTERNAL_HAS_CONSTEXPR_POPCOUNT 0
#endif
-#if ABSL_HAVE_BUILTIN(__builtin_clz) && ABSL_HAVE_BUILTIN(__builtin_clzll)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_clz) && \
+ ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_clzll)
#define ABSL_INTERNAL_CONSTEXPR_CLZ constexpr
#define ABSL_INTERNAL_HAS_CONSTEXPR_CLZ 1
#else
@@ -45,7 +53,8 @@
#define ABSL_INTERNAL_HAS_CONSTEXPR_CLZ 0
#endif
-#if ABSL_HAVE_BUILTIN(__builtin_ctz) && ABSL_HAVE_BUILTIN(__builtin_ctzll)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_ctz) && \
+ ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_ctzll)
#define ABSL_INTERNAL_CONSTEXPR_CTZ constexpr
#define ABSL_INTERNAL_HAS_CONSTEXPR_CTZ 1
#else
@@ -85,7 +94,7 @@
ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_POPCOUNT inline int
Popcount32(uint32_t x) noexcept {
-#if ABSL_HAVE_BUILTIN(__builtin_popcount)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_popcount)
static_assert(sizeof(unsigned int) == sizeof(x),
"__builtin_popcount does not take 32-bit arg");
return __builtin_popcount(x);
@@ -98,7 +107,7 @@
ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_POPCOUNT inline int
Popcount64(uint64_t x) noexcept {
-#if ABSL_HAVE_BUILTIN(__builtin_popcountll)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_popcountll)
static_assert(sizeof(unsigned long long) == sizeof(x), // NOLINT(runtime/int)
"__builtin_popcount does not take 64-bit arg");
return __builtin_popcountll(x);
@@ -122,7 +131,7 @@
ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_CLZ inline int
CountLeadingZeroes32(uint32_t x) {
-#if ABSL_HAVE_BUILTIN(__builtin_clz)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_clz)
// Use __builtin_clz, which uses the following instructions:
// x86: bsr, lzcnt
// ARM64: clz
@@ -169,7 +178,7 @@
ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_CLZ inline int
CountLeadingZeroes64(uint64_t x) {
-#if ABSL_HAVE_BUILTIN(__builtin_clzll)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_clzll)
// Use __builtin_clzll, which uses the following instructions:
// x86: bsr, lzcnt
// ARM64: clz
@@ -240,7 +249,7 @@
ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_CTZ inline int
CountTrailingZeroesNonzero32(uint32_t x) {
-#if ABSL_HAVE_BUILTIN(__builtin_ctz)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_ctz)
static_assert(sizeof(unsigned int) == sizeof(x),
"__builtin_ctz does not take 32-bit arg");
return __builtin_ctz(x);
@@ -262,7 +271,7 @@
ABSL_ATTRIBUTE_ALWAYS_INLINE ABSL_INTERNAL_CONSTEXPR_CTZ inline int
CountTrailingZeroesNonzero64(uint64_t x) {
-#if ABSL_HAVE_BUILTIN(__builtin_ctzll)
+#if ABSL_NUMERIC_INTERNAL_HAVE_BUILTIN_OR_GCC(__builtin_ctzll)
static_assert(sizeof(unsigned long long) == sizeof(x), // NOLINT(runtime/int)
"__builtin_ctzll does not take 64-bit arg");
return __builtin_ctzll(x);
diff --git a/absl/synchronization/mutex.cc b/absl/synchronization/mutex.cc
index d2468ce..7e66a7d 100644
--- a/absl/synchronization/mutex.cc
+++ b/absl/synchronization/mutex.cc
@@ -1372,7 +1372,9 @@
len += static_cast<int>(strlen(&b->buf[len]));
}
}
- ABSL_RAW_LOG(ERROR, "Acquiring %p Mutexes held: %s",
+ ABSL_RAW_LOG(ERROR,
+ "Acquiring absl::Mutex %p while holding %s; a cycle in the "
+ "historical lock ordering graph has been observed",
static_cast<void *>(mu), b->buf);
ABSL_RAW_LOG(ERROR, "Cycle: ");
int path_len = deadlock_graph->FindPath(
