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Diffstat (limited to 'security/sandbox/chromium/base/location.h')
-rw-r--r-- | security/sandbox/chromium/base/location.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/location.h b/security/sandbox/chromium/base/location.h new file mode 100644 index 0000000000..bcc3ca0e14 --- /dev/null +++ b/security/sandbox/chromium/base/location.h @@ -0,0 +1,142 @@ +// Copyright (c) 2012 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef BASE_LOCATION_H_ +#define BASE_LOCATION_H_ + +#include <stddef.h> + +#include <cassert> +#include <functional> +#include <string> + +#include "base/base_export.h" +#include "base/debug/debugging_buildflags.h" +#include "base/hash/hash.h" +#include "build/build_config.h" + +namespace base { + +#if defined(__has_builtin) +// Clang allows detection of these builtins. +#define SUPPORTS_LOCATION_BUILTINS \ + (__has_builtin(__builtin_FUNCTION) && __has_builtin(__builtin_FILE) && \ + __has_builtin(__builtin_LINE)) +#elif defined(COMPILER_GCC) && __GNUC__ >= 7 +// GCC has supported these for a long time, but they point at the function +// declaration in the case of default arguments, rather than at the call site. +#define SUPPORTS_LOCATION_BUILTINS 1 +#else +#define SUPPORTS_LOCATION_BUILTINS 0 +#endif + +// Location provides basic info where of an object was constructed, or was +// significantly brought to life. +class BASE_EXPORT Location { + public: + Location(); + Location(const Location& other); + + // Only initializes the file name and program counter, the source information + // will be null for the strings, and -1 for the line number. + // TODO(http://crbug.com/760702) remove file name from this constructor. + Location(const char* file_name, const void* program_counter); + + // Constructor should be called with a long-lived char*, such as __FILE__. + // It assumes the provided value will persist as a global constant, and it + // will not make a copy of it. + Location(const char* function_name, + const char* file_name, + int line_number, + const void* program_counter); + + // Comparator for hash map insertion. The program counter should uniquely + // identify a location. + bool operator==(const Location& other) const { + return program_counter_ == other.program_counter_; + } + + // Returns true if there is source code location info. If this is false, + // the Location object only contains a program counter or is + // default-initialized (the program counter is also null). + bool has_source_info() const { return function_name_ && file_name_; } + + // Will be nullptr for default initialized Location objects and when source + // names are disabled. + const char* function_name() const { return function_name_; } + + // Will be nullptr for default initialized Location objects and when source + // names are disabled. + const char* file_name() const { return file_name_; } + + // Will be -1 for default initialized Location objects and when source names + // are disabled. + int line_number() const { return line_number_; } + + // The address of the code generating this Location object. Should always be + // valid except for default initialized Location objects, which will be + // nullptr. + const void* program_counter() const { return program_counter_; } + + // Converts to the most user-readable form possible. If function and filename + // are not available, this will return "pc:<hex address>". + std::string ToString() const; + + static Location CreateFromHere(const char* file_name); + static Location CreateFromHere(const char* function_name, + const char* file_name, + int line_number); + +#if SUPPORTS_LOCATION_BUILTINS && BUILDFLAG(ENABLE_LOCATION_SOURCE) + static Location Current(const char* function_name = __builtin_FUNCTION(), + const char* file_name = __builtin_FILE(), + int line_number = __builtin_LINE()); +#elif SUPPORTS_LOCATION_BUILTINS + static Location Current(const char* file_name = __builtin_FILE()); +#else + static Location Current(); +#endif + + private: + const char* function_name_ = nullptr; + const char* file_name_ = nullptr; + int line_number_ = -1; + const void* program_counter_ = nullptr; +}; + +BASE_EXPORT const void* GetProgramCounter(); + +// The macros defined here will expand to the current function. +#if BUILDFLAG(ENABLE_LOCATION_SOURCE) + +// Full source information should be included. +#define FROM_HERE FROM_HERE_WITH_EXPLICIT_FUNCTION(__func__) +#define FROM_HERE_WITH_EXPLICIT_FUNCTION(function_name) \ + ::base::Location::CreateFromHere(function_name, __FILE__, __LINE__) + +#else + +// TODO(http://crbug.com/760702) remove the __FILE__ argument from these calls. +#define FROM_HERE ::base::Location::CreateFromHere(__FILE__) +#define FROM_HERE_WITH_EXPLICIT_FUNCTION(function_name) \ + ::base::Location::CreateFromHere(function_name, __FILE__, -1) + +#endif + +} // namespace base + +namespace std { + +// Specialization for using Location in hash tables. +template <> +struct hash<::base::Location> { + std::size_t operator()(const ::base::Location& loc) const { + const void* program_counter = loc.program_counter(); + return base::FastHash(base::as_bytes(base::make_span(&program_counter, 1))); + } +}; + +} // namespace std + +#endif // BASE_LOCATION_H_ |