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//===-- sanitizer_symbolizer.h ----------------------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// Symbolizer is used by sanitizers to map instruction address to a location in
// source code at run-time. Symbolizer either uses __sanitizer_symbolize_*
// defined in the program, or (if they are missing) tries to find and
// launch "llvm-symbolizer" commandline tool in a separate process and
// communicate with it.
// Generally we should try to avoid calling system library functions during
// symbolization (and use their replacements from sanitizer_libc.h instead).
#include "sanitizer_common.h"
#include "sanitizer_mutex.h"
namespace __sanitizer {
struct AddressInfo {
// Owns all the string members. Storage for them is
// (de)allocated using sanitizer internal allocator.
uptr address;
char *module;
uptr module_offset;
static const uptr kUnknown = ~(uptr)0;
char *function;
uptr function_offset;
char *file;
int line;
int column;
// Deletes all strings and resets all fields.
void Clear();
void FillAddressAndModuleInfo(uptr addr, const char *mod_name,
uptr mod_offset);
// Linked list of symbolized frames (each frame is described by AddressInfo).
struct SymbolizedStack {
SymbolizedStack *next;
AddressInfo info;
static SymbolizedStack *New(uptr addr);
// Deletes current, and all subsequent frames in the linked list.
// The object cannot be accessed after the call to this function.
void ClearAll();
// For now, DataInfo is used to describe global variable.
struct DataInfo {
// Owns all the string members. Storage for them is
// (de)allocated using sanitizer internal allocator.
char *module;
uptr module_offset;
char *name;
uptr start;
uptr size;
void Clear();
class Symbolizer {
/// Initialize and return platform-specific implementation of symbolizer
/// (if it wasn't already initialized).
static Symbolizer *GetOrInit();
// Returns a list of symbolized frames for a given address (containing
// all inlined functions, if necessary).
virtual SymbolizedStack *SymbolizePC(uptr address) {
return SymbolizedStack::New(address);
virtual bool SymbolizeData(uptr address, DataInfo *info) {
return false;
virtual bool GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
uptr *module_address) {
return false;
virtual bool CanReturnFileLineInfo() {
return false;
// Release internal caches (if any).
virtual void Flush() {}
// Attempts to demangle the provided C++ mangled name.
virtual const char *Demangle(const char *name) {
return name;
virtual void PrepareForSandboxing() {}
// Allow user to install hooks that would be called before/after Symbolizer
// does the actual file/line info fetching. Specific sanitizers may need this
// to distinguish system library calls made in user code from calls made
// during in-process symbolization.
typedef void (*StartSymbolizationHook)();
typedef void (*EndSymbolizationHook)();
// May be called at most once.
void AddHooks(StartSymbolizationHook start_hook,
EndSymbolizationHook end_hook);
/// Platform-specific function for creating a Symbolizer object.
static Symbolizer *PlatformInit();
/// Initialize the symbolizer in a disabled state. Not thread safe.
static Symbolizer *Disable();
static Symbolizer *symbolizer_;
static StaticSpinMutex init_mu_;
static LowLevelAllocator symbolizer_allocator_;
StartSymbolizationHook start_hook_;
EndSymbolizationHook end_hook_;
class SymbolizerScope {
explicit SymbolizerScope(const Symbolizer *sym);
const Symbolizer *sym_;
class ExternalSymbolizerInterface {
// Can't declare pure virtual functions in sanitizer runtimes:
// __cxa_pure_virtual might be unavailable.
virtual char *SendCommand(bool is_data, const char *module_name,
uptr module_offset) {
// SymbolizerProcess encapsulates communication between the tool and
// external symbolizer program, running in a different subprocess.
// SymbolizerProcess may not be used from two threads simultaneously.
class SymbolizerProcess : public ExternalSymbolizerInterface {
explicit SymbolizerProcess(const char *path);
char *SendCommand(bool is_data, const char *module_name,
uptr module_offset) override;
bool Restart();
char *SendCommandImpl(bool is_data, const char *module_name,
uptr module_offset);
bool ReadFromSymbolizer(char *buffer, uptr max_length);
bool WriteToSymbolizer(const char *buffer, uptr length);
bool StartSymbolizerSubprocess();
virtual bool RenderInputCommand(char *buffer, uptr max_length, bool is_data,
const char *module_name,
uptr module_offset) const {
virtual bool ReachedEndOfOutput(const char *buffer, uptr length) const {
virtual void ExecuteWithDefaultArgs(const char *path_to_binary) const {
const char *path_;
int input_fd_;
int output_fd_;
static const uptr kBufferSize = 16 * 1024;
char buffer_[kBufferSize];
static const uptr kMaxTimesRestarted = 5;
static const int kSymbolizerStartupTimeMillis = 10;
uptr times_restarted_;
bool failed_to_start_;
bool reported_invalid_path_;
} // namespace __sanitizer