blob: 92332230f80a03207620e5c13255d82238048532 [file] [log] [blame]
//===-- 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 FillModuleInfo(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 SymbolizerTool;
class Symbolizer final {
/// 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).
SymbolizedStack *SymbolizePC(uptr address);
bool SymbolizeData(uptr address, DataInfo *info);
// The module names Symbolizer returns are stable and unique for every given
// module. It is safe to store and compare them as pointers.
bool GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
uptr *module_address);
const char *GetModuleNameForPc(uptr pc) {
const char *module_name = nullptr;
uptr unused;
if (GetModuleNameAndOffsetForPC(pc, &module_name, &unused))
return module_name;
return nullptr;
// Release internal caches (if any).
void Flush();
// Attempts to demangle the provided C++ mangled name.
const char *Demangle(const char *name);
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);
// GetModuleNameAndOffsetForPC has to return a string to the caller.
// Since the corresponding module might get unloaded later, we should create
// our owned copies of the strings that we can safely return.
// ModuleNameOwner does not provide any synchronization, thus calls to
// its method should be protected by |mu_|.
class ModuleNameOwner {
explicit ModuleNameOwner(BlockingMutex *synchronized_by)
: storage_(kInitialCapacity), last_match_(nullptr),
mu_(synchronized_by) {}
const char *GetOwnedCopy(const char *str);
static const uptr kInitialCapacity = 1000;
InternalMmapVector<const char*> storage_;
const char *last_match_;
BlockingMutex *mu_;
} module_names_;
/// Platform-specific function for creating a Symbolizer object.
static Symbolizer *PlatformInit();
bool FindModuleNameAndOffsetForAddress(uptr address, const char **module_name,
uptr *module_offset);
LoadedModule *FindModuleForAddress(uptr address);
LoadedModule modules_[kMaxNumberOfModules];
uptr n_modules_;
// If stale, need to reload the modules before looking up addresses.
bool modules_fresh_;
// Platform-specific default demangler, must not return nullptr.
const char *PlatformDemangle(const char *name);
void PlatformPrepareForSandboxing();
static Symbolizer *symbolizer_;
static StaticSpinMutex init_mu_;
// Mutex locked from public methods of |Symbolizer|, so that the internals
// (including individual symbolizer tools and platform-specific methods) are
// always synchronized.
BlockingMutex mu_;
typedef IntrusiveList<SymbolizerTool>::Iterator Iterator;
IntrusiveList<SymbolizerTool> tools_;
explicit Symbolizer(IntrusiveList<SymbolizerTool> tools);
static LowLevelAllocator symbolizer_allocator_;
StartSymbolizationHook start_hook_;
EndSymbolizationHook end_hook_;
class SymbolizerScope {
explicit SymbolizerScope(const Symbolizer *sym);
const Symbolizer *sym_;
} // namespace __sanitizer