tvl-depot/absl/debugging/internal/symbolize.h
Abseil Team 12bc53e031 Export of internal Abseil changes
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c99f979ad34f155fbeeea69b88bdc7458d89a21c by Derek Mauro <dmauro@google.com>:

Remove a floating point division by zero test.

This isn't testing behavior related to the library, and MSVC warns
about it in opt mode.

PiperOrigin-RevId: 285220804

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68b015491f0dbf1ab547994673281abd1f34cd4b by Gennadiy Rozental <rogeeff@google.com>:

This CL introduces following changes to the class FlagImpl:
* We eliminate the CommandLineFlagLocks struct. Instead callback guard and callback function are combined into a single CallbackData struct, while primary data lock is stored separately.
* CallbackData member of class FlagImpl is initially set to be nullptr and is only allocated and initialized when a flag's callback is being set. For most flags we do not pay for the extra space and extra absl::Mutex now.
* Primary data guard is stored in data_guard_ data member. This is a properly aligned character buffer of necessary size. During initialization of the flag we construct absl::Mutex in this space using placement new call.
* We now avoid extra value copy after successful attempt to parse value out of string. Instead we swap flag's current value with tentative value we just produced.

PiperOrigin-RevId: 285132636

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ed45d118fb818969eb13094cf7827c885dfc562c by Tom Manshreck <shreck@google.com>:

Change null-term* (and nul-term*) to NUL-term* in comments

PiperOrigin-RevId: 285036610

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729619017944db895ce8d6d29c1995aa2e5628a5 by Derek Mauro <dmauro@google.com>:

Use the Posix implementation of thread identity on MinGW.
Some versions of MinGW suffer from thread_local bugs.

PiperOrigin-RevId: 285022920

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39a25493503c76885bc3254c28f66a251c5b5bb0 by Greg Falcon <gfalcon@google.com>:

Implementation detail change.

Add further ABSL_NAMESPACE_BEGIN and _END annotation macros to files in Abseil.

PiperOrigin-RevId: 285012012
GitOrigin-RevId: c99f979ad34f155fbeeea69b88bdc7458d89a21c
Change-Id: I4c85d3704e45d11a9ac50d562f39640a6adbedc1
2019-12-12 15:37:13 -05:00

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4.5 KiB
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// 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
//
// https://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>
#include "absl/base/config.h"
#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__) && !defined(__wasm__)
#define ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE 1
#include <elf.h>
#include <link.h> // For ElfW() macro.
#include <functional>
#include <string>
namespace absl {
ABSL_NAMESPACE_BEGIN
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
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
namespace absl {
ABSL_NAMESPACE_BEGIN
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
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_