Changes imported from Abseil "staging" branch:

  - f0a03a750a36dfbd7ab06d2913430ed5f988fd68 Add absl::RegisterSymbolizer() to mutex_nonprod.cc for AP... by Derek Mauro <dmauro@google.com>
  - f34a2ee35b4f6b321c570c51b0c381647176df63 Add the async signal-safe Symbolizer to Abseil. by Derek Mauro <dmauro@google.com>
  - 6a29ec2d6dc080691f6d32e1982201d1d173bdb3 Document preferred placement of ABSL_CONST_INIT attribute... by Abseil Team <absl-team@google.com>
  - 6f04ed6aa9c19bd717f0e8f422a97f3e3368cf30 Internal change. by Abseil Team <absl-team@google.com>
  - 0af9a330aff8fc0b41dcb3fe519930c36b01a9ef Declare absl::raw_logging_internal::SafeWriteToStderr in ... by Abseil Team <absl-team@google.com>
  - 223ff26745d31dfb4b59c36f3dee5441506af3c2 Fix ABSL_ARRAYSIZE() to handle rvalues. by Xiaoyi Zhang <zhangxy@google.com>

GitOrigin-RevId: f0a03a750a36dfbd7ab06d2913430ed5f988fd68
Change-Id: I491f9cc81ca3ee078fb737cbf8fa9bf6a730eee1

absl/base/attributes.h

@@ -543,11 +543,18 @@
 // not compile (on supported platforms) unless the variable has a constant
 // not compile (on supported platforms) unless the variable has a constant
 // initializer. This is useful for variables with static and thread storage
 // initializer. This is useful for variables with static and thread storage
 // duration, because it guarantees that they will not suffer from the so-called
 // duration, because it guarantees that they will not suffer from the so-called
-// "static init order fiasco".
+// "static init order fiasco".  Prefer to put this attribute on the most visible
+// declaration of the variable, if there's more than one, because code that
+// accesses the variable can then use the attribute for optimization.
 //
 //
 // Example:
 // Example:
 //
 //
-//   ABSL_CONST_INIT static MyType my_var = MakeMyType(...);
+//   class MyClass {
+//    public:
+//     ABSL_CONST_INIT static MyType my_var;
+//   };
+//
+//   MyType MyClass::my_var = MakeMyType(...);
 //
 //
 // Note that this attribute is redundant if the variable is declared constexpr.
 // Note that this attribute is redundant if the variable is declared constexpr.
 #if ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization)
 #if ABSL_HAVE_CPP_ATTRIBUTE(clang::require_constant_initialization)

absl/base/internal/raw_logging.cc

@@ -104,12 +104,6 @@ inline static bool VADoRawLog(char** buf, int* size,
 
 
 static constexpr int kLogBufSize = 3000;
 static constexpr int kLogBufSize = 3000;
 
 
-namespace absl {
-namespace raw_logging_internal {
-void SafeWriteToStderr(const char *s, size_t len);
-}  // namespace raw_logging_internal
-}  // namespace absl
-
 namespace {
 namespace {
 
 
 // CAVEAT: vsnprintf called from *DoRawLog below has some (exotic) code paths
 // CAVEAT: vsnprintf called from *DoRawLog below has some (exotic) code paths
@@ -188,12 +182,6 @@ void RawLogVA(absl::LogSeverity severity, const char* file, int line,
 
 
 namespace absl {
 namespace absl {
 namespace raw_logging_internal {
 namespace raw_logging_internal {
-
-// Writes the provided buffer directly to stderr, in a safe, low-level manner.
-//
-// In POSIX this means calling write(), which is async-signal safe and does
-// not malloc.  If the platform supports the SYS_write syscall, we invoke that
-// directly to side-step any libc interception.
 void SafeWriteToStderr(const char *s, size_t len) {
 void SafeWriteToStderr(const char *s, size_t len) {
 #if defined(ABSL_HAVE_SYSCALL_WRITE)
 #if defined(ABSL_HAVE_SYSCALL_WRITE)
   syscall(SYS_write, STDERR_FILENO, s, len);
   syscall(SYS_write, STDERR_FILENO, s, len);

absl/base/internal/raw_logging.h

@@ -74,6 +74,13 @@ namespace raw_logging_internal {
 void RawLog(absl::LogSeverity severity, const char* file, int line,
 void RawLog(absl::LogSeverity severity, const char* file, int line,
             const char* format, ...) ABSL_PRINTF_ATTRIBUTE(4, 5);
             const char* format, ...) ABSL_PRINTF_ATTRIBUTE(4, 5);
 
 
+// Writes the provided buffer directly to stderr, in a safe, low-level manner.
+//
+// In POSIX this means calling write(), which is async-signal safe and does
+// not malloc.  If the platform supports the SYS_write syscall, we invoke that
+// directly to side-step any libc interception.
+void SafeWriteToStderr(const char *s, size_t len);
+
 // compile-time function to get the "base" filename, that is, the part of
 // compile-time function to get the "base" filename, that is, the part of
 // a filename after the last "/" or "\" path separator.  The search starts at
 // a filename after the last "/" or "\" path separator.  The search starts at
 // the end of the std::string; the second parameter is the length of the std::string.
 // the end of the std::string; the second parameter is the length of the std::string.

absl/base/macros.h

@@ -46,7 +46,7 @@
 namespace absl {
 namespace absl {
 namespace macros_internal {
 namespace macros_internal {
 template <typename T, size_t N>
 template <typename T, size_t N>
-char (&ArraySizeHelper(T (&array)[N]))[N];
+auto ArraySizeHelper(const T (&array)[N]) -> char (&)[N];
 }  // namespace macros_internal
 }  // namespace macros_internal
 }  // namespace absl
 }  // namespace absl
 #define ABSL_ARRAYSIZE(array) \
 #define ABSL_ARRAYSIZE(array) \

absl/debugging/BUILD.bazel

@@ -41,6 +41,42 @@ cc_library(
 )
 )
 
 
 cc_library(
 cc_library(
+    name = "symbolize",
+    srcs = [
+        "symbolize.cc",
+        "symbolize_elf.inc",
+        "symbolize_unimplemented.inc",
+    ],
+    hdrs = [
+        "internal/symbolize.h",
+        "symbolize.h",
+    ],
+    copts = ABSL_DEFAULT_COPTS,
+    deps = [
+        ":debugging_internal",
+        ":demangle_internal",
+        "//absl/base",
+        "//absl/base:core_headers",
+        "//absl/base:malloc_internal",
+    ],
+)
+
+cc_test(
+    name = "symbolize_test",
+    srcs = ["symbolize_test.cc"],
+    copts = ABSL_TEST_COPTS,
+    deps = [
+        ":stack_consumption",
+        ":symbolize",
+        "//absl/base",
+        "//absl/base:core_headers",
+        "//absl/base:malloc_extension",
+        "//absl/memory",
+        "@com_google_googletest//:gtest",
+    ],
+)
+
+cc_library(
     name = "debugging_internal",
     name = "debugging_internal",
     srcs = [
     srcs = [
         "internal/address_is_readable.cc",
         "internal/address_is_readable.cc",

absl/debugging/CMakeLists.txt

@@ -17,6 +17,7 @@
 list(APPEND DEBUGGING_PUBLIC_HEADERS
 list(APPEND DEBUGGING_PUBLIC_HEADERS
   "leak_check.h"
   "leak_check.h"
   "stacktrace.h"
   "stacktrace.h"
+  "symbolize.h"
 )
 )
 
 
 
 
@@ -25,6 +26,7 @@ list(APPEND DEBUGGING_INTERNAL_HEADERS
   "internal/demangle.h"
   "internal/demangle.h"
   "internal/elf_mem_image.h"
   "internal/elf_mem_image.h"
   "internal/stacktrace_config.h"
   "internal/stacktrace_config.h"
+  "internal/symbolize.h"
   "internal/vdso_support.h"
   "internal/vdso_support.h"
 )
 )
 
 
@@ -32,13 +34,21 @@ list(APPEND DEBUGGING_INTERNAL_HEADERS
 list(APPEND STACKTRACE_SRC
 list(APPEND STACKTRACE_SRC
   "stacktrace.cc"
   "stacktrace.cc"
   "internal/address_is_readable.cc"
   "internal/address_is_readable.cc"
-  "internal/demangle.cc"
   "internal/elf_mem_image.cc"
   "internal/elf_mem_image.cc"
   "internal/vdso_support.cc"
   "internal/vdso_support.cc"
   ${DEBUGGING_PUBLIC_HEADERS}
   ${DEBUGGING_PUBLIC_HEADERS}
   ${DEBUGGING_INTERNAL_HEADERS}
   ${DEBUGGING_INTERNAL_HEADERS}
 )
 )
 
 
+list(APPEND SYMBOLIZE_SRC
+  "symbolize.cc"
+  "symbolize_elf.inc"
+  "symbolize_unimplemented.inc"
+  "internal/demangle.cc"
+  ${DEBUGGING_PUBLIC_HEADERS}
+  ${DEBUGGING_INTERNAL_HEADERS}
+)
+
 absl_library(
 absl_library(
   TARGET
   TARGET
     absl_stacktrace
     absl_stacktrace
@@ -48,6 +58,14 @@ absl_library(
     stacktrace
     stacktrace
 )
 )
 
 
+absl_library(
+  TARGET
+    absl_symbolize
+  SOURCES
+    ${SYMBOLIZE_SRC}
+  EXPORT_NAME
+    symbolize
+)
 
 
 list(APPEND LEAK_CHECK_SRC
 list(APPEND LEAK_CHECK_SRC
   "leak_check.cc"
   "leak_check.cc"
@@ -112,9 +130,19 @@ absl_test(
   SOURCES
   SOURCES
     ${DEMANGLE_TEST_SRC}
     ${DEMANGLE_TEST_SRC}
   PUBLIC_LIBRARIES
   PUBLIC_LIBRARIES
-    absl_stacktrace absl_stack_consumption
+    absl_symbolize absl_stack_consumption
 )
 )
 
 
+list(APPEND SYMBOLIZE_TEST_SRC "symbolize_test.cc")
+
+absl_test(
+  TARGET
+    symbolize_test
+  SOURCES
+    ${SYMBOLIZE_TEST_SRC}
+  PUBLIC_LIBRARIES
+    absl_symbolize absl_stack_consumption
+)
 
 
 # test leak_check_test
 # test leak_check_test
 list(APPEND LEAK_CHECK_TEST_SRC "leak_check_test.cc")
 list(APPEND LEAK_CHECK_TEST_SRC "leak_check_test.cc")

absl/debugging/internal/symbolize.h

+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file contains internal parts of the Abseil symbolizer.
+// Do not depend on the anything in this file, it may change at anytime.
+
+#ifndef ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
+#define ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
+
+#include <cstddef>
+#include <cstdint>
+
+#ifdef ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
+#error ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE cannot be directly set
+#elif defined(__ELF__) && defined(__GLIBC__) && !defined(__native_client__) && \
+    !defined(__asmjs__)
+#define ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE 1
+
+#include <elf.h>
+#include <link.h>  // For ElfW() macro.
+#include <functional>
+#include <string>
+
+namespace absl {
+namespace debugging_internal {
+
+// Iterates over all sections, invoking callback on each with the section name
+// and the section header.
+//
+// Returns true on success; otherwise returns false in case of errors.
+//
+// This is not async-signal-safe.
+bool ForEachSection(
+    int fd, const std::function<bool(const std::string& name, const ElfW(Shdr) &)>&
+                callback);
+
+// Gets the section header for the given name, if it exists. Returns true on
+// success. Otherwise, returns false.
+bool GetSectionHeaderByName(int fd, const char *name, size_t name_len,
+                            ElfW(Shdr) *out);
+
+}  // namespace debugging_internal
+}  // namespace absl
+
+#endif  // ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
+
+namespace absl {
+namespace debugging_internal {
+
+struct SymbolDecoratorArgs {
+  // The program counter we are getting symbolic name for.
+  const void *pc;
+  // 0 for main executable, load address for shared libraries.
+  ptrdiff_t relocation;
+  // Read-only file descriptor for ELF image covering "pc",
+  // or -1 if no such ELF image exists in /proc/self/maps.
+  int fd;
+  // Output buffer, size.
+  // Note: the buffer may not be empty -- default symbolizer may have already
+  // produced some output, and earlier decorators may have adorned it in
+  // some way. You are free to replace or augment the contents (within the
+  // symbol_buf_size limit).
+  char *const symbol_buf;
+  size_t symbol_buf_size;
+  // Temporary scratch space, size.
+  // Use that space in preference to allocating your own stack buffer to
+  // conserve stack.
+  char *const tmp_buf;
+  size_t tmp_buf_size;
+  // User-provided argument
+  void* arg;
+};
+using SymbolDecorator = void (*)(const SymbolDecoratorArgs *);
+
+// Installs a function-pointer as a decorator. Returns a value less than zero
+// if the system cannot install the decorator. Otherwise, returns a unique
+// identifier corresponding to the decorator. This identifier can be used to
+// uninstall the decorator - See RemoveSymbolDecorator() below.
+int InstallSymbolDecorator(SymbolDecorator decorator, void* arg);
+
+// Removes a previously installed function-pointer decorator. Parameter "ticket"
+// is the return-value from calling InstallSymbolDecorator().
+bool RemoveSymbolDecorator(int ticket);
+
+// Remove all installed decorators.  Returns true if successful, false if
+// symbolization is currently in progress.
+bool RemoveAllSymbolDecorators(void);
+
+// Registers an address range to a file mapping.
+//
+// Preconditions:
+//   start <= end
+//   filename != nullptr
+//
+// Returns true if the file was successfully registered.
+bool RegisterFileMappingHint(
+    const void* start, const void* end, uint64_t offset, const char* filename);
+
+// Looks up the file mapping registered by RegisterFileMappingHint for an
+// address range. If there is one, the file name is stored in *filename and
+// *start and *end are modified to reflect the registered mapping. Returns
+// whether any hint was found.
+bool GetFileMappingHint(const void** start,
+                        const void** end,
+                        uint64_t    *  offset,
+                        const char** filename);
+
+}  // namespace debugging_internal
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_

absl/debugging/symbolize.cc

+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/debugging/symbolize.h"
+
+#ifdef ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
+#include "absl/debugging/symbolize_elf.inc"
+#else
+#include "absl/debugging/symbolize_unimplemented.inc"
+#endif

absl/debugging/symbolize.h

+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_DEBUGGING_SYMBOLIZE_H_
+#define ABSL_DEBUGGING_SYMBOLIZE_H_
+
+#include "absl/debugging/internal/symbolize.h"
+
+namespace absl {
+
+// Initializes this module. Symbolize() may fail prior calling this function.
+// `argv0` is the path to this program, which is usually obtained in main()
+// though argv[0].
+void InitializeSymbolizer(const char* argv0);
+
+// Symbolizes a program counter.  On success, returns true and write the
+// symbol name to "out".  The symbol name is demangled if possible
+// (supports symbols generated by GCC 3.x or newer), may be truncated, and
+// will be '\0' terminated.  Otherwise, returns false.
+bool Symbolize(const void *pc, char *out, int out_size);
+
+}  // namespace absl
+
+#endif  // ABSL_DEBUGGING_SYMBOLIZE_H_

absl/debugging/symbolize_unimplemented.inc

+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <cstdint>
+
+#include "absl/base/internal/raw_logging.h"
+
+namespace absl {
+
+namespace debugging_internal {
+
+int InstallSymbolDecorator(SymbolDecorator, void*) { return -1; }
+bool RemoveSymbolDecorator(int) { return false; }
+bool RemoveAllSymbolDecorators(void) { return false; }
+bool RegisterFileMappingHint(const void *, const void *, uint64_t, const char *) {
+  return false;
+}
+
+}  // namespace debugging_internal
+
+void InitializeSymbolizer(const char*) {}
+bool Symbolize(const void *, char *, int) { return false; }
+
+}  // namespace absl

absl/synchronization/internal/mutex_nonprod.cc

@@ -313,4 +313,6 @@ bool Condition::Eval() const {
   return (this->eval_ == nullptr) || (*this->eval_)(this);
   return (this->eval_ == nullptr) || (*this->eval_)(this);
 }
 }
 
 
+void RegisterSymbolizer(bool (*)(const void*, char*, int)) {}
+
 }  // namespace absl
 }  // namespace absl