1 //===-- sanitizer_symbolizer.h ----------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Symbolizer is used by sanitizers to map instruction address to a location in
11 // source code at run-time. Symbolizer either uses __sanitizer_symbolize_*
12 // defined in the program, or (if they are missing) tries to find and
13 // launch "llvm-symbolizer" commandline tool in a separate process and
14 // communicate with it.
16 // Generally we should try to avoid calling system library functions during
17 // symbolization (and use their replacements from sanitizer_libc.h instead).
18 //===----------------------------------------------------------------------===//
19 #ifndef SANITIZER_SYMBOLIZER_H
20 #define SANITIZER_SYMBOLIZER_H
22 #include "sanitizer_common.h"
23 #include "sanitizer_mutex.h"
25 namespace __sanitizer {
28 // Owns all the string members. Storage for them is
29 // (de)allocated using sanitizer internal allocator.
35 static const uptr kUnknown = ~(uptr)0;
44 // Deletes all strings and resets all fields.
46 void FillModuleInfo(const char *mod_name, uptr mod_offset);
49 // Linked list of symbolized frames (each frame is described by AddressInfo).
50 struct SymbolizedStack {
51 SymbolizedStack *next;
53 static SymbolizedStack *New(uptr addr);
54 // Deletes current, and all subsequent frames in the linked list.
55 // The object cannot be accessed after the call to this function.
62 // For now, DataInfo is used to describe global variable.
64 // Owns all the string members. Storage for them is
65 // (de)allocated using sanitizer internal allocator.
80 class Symbolizer final {
82 /// Initialize and return platform-specific implementation of symbolizer
83 /// (if it wasn't already initialized).
84 static Symbolizer *GetOrInit();
85 static void LateInitialize();
86 // Returns a list of symbolized frames for a given address (containing
87 // all inlined functions, if necessary).
88 SymbolizedStack *SymbolizePC(uptr address);
89 bool SymbolizeData(uptr address, DataInfo *info);
91 // The module names Symbolizer returns are stable and unique for every given
92 // module. It is safe to store and compare them as pointers.
93 bool GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
94 uptr *module_address);
95 const char *GetModuleNameForPc(uptr pc) {
96 const char *module_name = nullptr;
98 if (GetModuleNameAndOffsetForPC(pc, &module_name, &unused))
103 // Release internal caches (if any).
105 // Attempts to demangle the provided C++ mangled name.
106 const char *Demangle(const char *name);
107 void PrepareForSandboxing();
109 // Allow user to install hooks that would be called before/after Symbolizer
110 // does the actual file/line info fetching. Specific sanitizers may need this
111 // to distinguish system library calls made in user code from calls made
112 // during in-process symbolization.
113 typedef void (*StartSymbolizationHook)();
114 typedef void (*EndSymbolizationHook)();
115 // May be called at most once.
116 void AddHooks(StartSymbolizationHook start_hook,
117 EndSymbolizationHook end_hook);
119 const LoadedModule *FindModuleForAddress(uptr address);
122 // GetModuleNameAndOffsetForPC has to return a string to the caller.
123 // Since the corresponding module might get unloaded later, we should create
124 // our owned copies of the strings that we can safely return.
125 // ModuleNameOwner does not provide any synchronization, thus calls to
126 // its method should be protected by |mu_|.
127 class ModuleNameOwner {
129 explicit ModuleNameOwner(BlockingMutex *synchronized_by)
130 : storage_(kInitialCapacity), last_match_(nullptr),
131 mu_(synchronized_by) {}
132 const char *GetOwnedCopy(const char *str);
135 static const uptr kInitialCapacity = 1000;
136 InternalMmapVector<const char*> storage_;
137 const char *last_match_;
142 /// Platform-specific function for creating a Symbolizer object.
143 static Symbolizer *PlatformInit();
145 bool FindModuleNameAndOffsetForAddress(uptr address, const char **module_name,
146 uptr *module_offset);
147 ListOfModules modules_;
148 // If stale, need to reload the modules before looking up addresses.
151 // Platform-specific default demangler, must not return nullptr.
152 const char *PlatformDemangle(const char *name);
153 void PlatformPrepareForSandboxing();
155 static Symbolizer *symbolizer_;
156 static StaticSpinMutex init_mu_;
158 // Mutex locked from public methods of |Symbolizer|, so that the internals
159 // (including individual symbolizer tools and platform-specific methods) are
160 // always synchronized.
163 IntrusiveList<SymbolizerTool> tools_;
165 explicit Symbolizer(IntrusiveList<SymbolizerTool> tools);
167 static LowLevelAllocator symbolizer_allocator_;
169 StartSymbolizationHook start_hook_;
170 EndSymbolizationHook end_hook_;
171 class SymbolizerScope {
173 explicit SymbolizerScope(const Symbolizer *sym);
176 const Symbolizer *sym_;
180 #ifdef SANITIZER_WINDOWS
181 void InitializeDbgHelpIfNeeded();
184 } // namespace __sanitizer
186 #endif // SANITIZER_SYMBOLIZER_H