| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * 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 |
| * |
| * http://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 is a standalone one-header-file library using only C++03. |
| // |
| // It assumes that the program is compiled for the "Itanium" C++ ABI |
| // (http://itanium-cxx-abi.github.io/cxx-abi/), a common C++ ABI used on many |
| // CPU architectures and operating systems. |
| // |
| |
| #ifndef RTTI_DUMP |
| #define RTTI_DUMP |
| |
| #include <assert.h> |
| #include <dlfcn.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include <set> |
| #include <string> |
| #include <typeinfo> |
| |
| #if defined(__ANDROID__) && !defined(RTTI_DUMP_USE_PRINTF) |
| #include <android/log.h> |
| #define RTTI_DUMP_LOG(fmt, ...) \ |
| __android_log_print(ANDROID_LOG_INFO, "rtti_dump", fmt, ## __VA_ARGS__) |
| #else |
| #define RTTI_DUMP_LOG(fmt, ...) printf(fmt "\n", ## __VA_ARGS__) |
| #endif |
| |
| // Avoid compiler warnings. |
| #define RTTI_DUMP_UNUSED __attribute__((unused)) |
| |
| // Use an anonymous namespace so this header file can be included at the top of |
| // multiple C++ source files without breaking the One Definition Rule. |
| namespace rtti_dump { |
| namespace { |
| |
| // Returns the type of the current exception object or NULL if the thread is |
| // not currently in a catch block. |
| extern "C" const std::type_info *__cxa_current_exception_type(); |
| |
| // Using run-time type information, returns an std::type_info* corresponding to |
| // the most-derived class of a pointer to an object. The pointed-to type must |
| // be a polymorphic class. (i.e. The class must have a virtual function or a |
| // base class with a virtual function.) |
| // |
| // The function can return NULL if the object's vtable comes from an object |
| // file compiled without -frtti. |
| template <typename T> |
| RTTI_DUMP_UNUSED const std::type_info *runtime_typeid(const volatile T *dynptr) { |
| T *dynptr_unqual = const_cast<T*>(dynptr); |
| |
| // Use dynamic_cast<void*> to ensure that T is polymorphic. The result is |
| // discarded just in case the most-derived object vtable and the subobject |
| // vtable point to different typeinfo objects. (XXX: I *think* that's |
| // impossible, though.) |
| (void)sizeof(dynamic_cast<void*>(dynptr_unqual)); |
| |
| void *vptr = *reinterpret_cast<void**>(dynptr_unqual); |
| void *typeid_void = reinterpret_cast<void**>(vptr)[-1]; |
| return reinterpret_cast<const std::type_info*>(typeid_void); |
| } |
| |
| // Returns the name of the DSO or binary containing the given address. |
| RTTI_DUMP_UNUSED std::string dladdr_fname(const void *ptr) { |
| Dl_info info = { 0 }; |
| if (!dladdr(const_cast<void*>(ptr), &info)) { |
| char buf[64]; |
| snprintf(buf, sizeof(buf), "[error: dladdr failed - %d]", errno); |
| return buf; |
| } else { |
| return std::string(info.dli_fname); |
| } |
| } |
| |
| // Dump the address of the std::type_info object, its name, and the shared |
| // object where the type_info object is defined. |
| RTTI_DUMP_UNUSED |
| void dump_type(const std::type_info *type, const char *label="dump_type", int indent=0) { |
| const std::string prefix = label + std::string(": ") + std::string(indent, ' '); |
| if (type == NULL) { |
| RTTI_DUMP_LOG("%sERROR: dump_type called with type==NULL!", prefix.c_str()); |
| } else { |
| struct type_info { |
| virtual ~type_info() {} |
| const char *type_name; |
| }; |
| assert(sizeof(type_info) == sizeof(std::type_info)); |
| const char *const name = type->name(); |
| const char *const raw_name = reinterpret_cast<const type_info*>(type)->type_name; |
| if (name == raw_name) { |
| RTTI_DUMP_LOG("%stype %s:", prefix.c_str(), name); |
| } else if (raw_name + 1 == name) { |
| RTTI_DUMP_LOG("%stype %s (raw name == '%s' @ %p):", prefix.c_str(), name, raw_name, raw_name); |
| } else { |
| RTTI_DUMP_LOG("%stype %s (raw name == %p):", prefix.c_str(), name, raw_name); |
| } |
| RTTI_DUMP_LOG("%s type_info obj: %p (in %s)", |
| prefix.c_str(), type, dladdr_fname(type).c_str()); |
| RTTI_DUMP_LOG("%s type_info name: %p (in %s)", |
| prefix.c_str(), name, dladdr_fname(name).c_str()); |
| } |
| } |
| |
| // Call from a catch block to dump the type of the current exception. |
| RTTI_DUMP_UNUSED |
| void dump_current_exception(const char *label="dump_current_exception") { |
| const std::type_info *type = __cxa_current_exception_type(); |
| if (type != NULL) { |
| dump_type(type, label); |
| } else { |
| RTTI_DUMP_LOG("%s: ERROR: dump_current_exception called outside a catch block!", label); |
| } |
| } |
| |
| namespace hierarchy_dumper_internals { |
| |
| // std::type_info has virtual member functions, so the most-derived type of |
| // a pointer to a std::type_info object can be determined at run-time by |
| // looking for the std::type_info's own std::type_info. We rely upon this |
| // property to walk a class's RTTI graph at run-time. |
| |
| struct __class_type_info : std::type_info {}; |
| |
| struct __si_class_type_info : __class_type_info { |
| const __class_type_info *__base_type; |
| }; |
| |
| struct __base_class_type_info { |
| const __class_type_info* __base_type; |
| long __offset_flags; |
| }; |
| |
| struct __vmi_class_type_info : __class_type_info { |
| unsigned int __flags; |
| unsigned int __base_count; |
| __base_class_type_info __base_info[1]; |
| }; |
| |
| class Dumper { |
| const char *label_; |
| std::set<const std::type_info*> seen_; |
| public: |
| Dumper(const char *label) : label_(label) {} |
| void dump_type(const std::type_info *info, int indent); |
| }; |
| |
| const int kIndent = 4; |
| |
| void Dumper::dump_type(const std::type_info *info, int indent) { |
| ::rtti_dump::dump_type(info, label_, indent * kIndent); |
| |
| if (info == NULL) { |
| return; |
| } |
| |
| const std::type_info *info_type = runtime_typeid(info); |
| __base_class_type_info lone_base = { 0 }; |
| const __base_class_type_info *base_table = NULL; |
| unsigned int base_count = 0; |
| |
| // Determine type equality using a string comparison, because this dumping |
| // system doesn't trust std::type_info::operator== to work with multiple |
| // shared objects. |
| |
| const int sub_indent_sp = (indent + 1) * kIndent; |
| |
| if (info_type == NULL) { |
| // I don't think info_type can ever be NULL here. |
| RTTI_DUMP_LOG("%s: %*sERROR: runtime_typeid(info) was NULL!", label_, sub_indent_sp, ""); |
| } else if (!strcmp(info_type->name(), "N10__cxxabiv120__si_class_type_infoE")) { |
| const __si_class_type_info &infox = |
| *reinterpret_cast<const __si_class_type_info*>(info); |
| lone_base.__base_type = infox.__base_type; |
| base_count = 1; |
| base_table = &lone_base; |
| } else if (!strcmp(info_type->name(), "N10__cxxabiv121__vmi_class_type_infoE")) { |
| const __vmi_class_type_info &infox = |
| *reinterpret_cast<const __vmi_class_type_info*>(info); |
| base_count = infox.__base_count; |
| base_table = infox.__base_info; |
| } |
| |
| if (base_count > 0) { |
| if (seen_.find(info) != seen_.end()) { |
| RTTI_DUMP_LOG("%s: %*sbase classes: ...elided...", label_, sub_indent_sp, ""); |
| } else { |
| RTTI_DUMP_LOG("%s: %*sbase classes:", label_, sub_indent_sp, ""); |
| seen_.insert(info); |
| for (unsigned int i = 0; i < base_count; ++i) { |
| dump_type(base_table[i].__base_type, indent + 2); |
| } |
| } |
| } |
| } |
| } // namespace hierarchy_dumper_internals |
| |
| // Dump the std::type_info object, and if it represents a class with base |
| // classes, then dumps the class hierarchy. |
| RTTI_DUMP_UNUSED |
| void dump_class_hierarchy(const std::type_info *info, const char *label="dump_class_hierarchy") { |
| hierarchy_dumper_internals::Dumper dumper(label); |
| dumper.dump_type(info, 0); |
| } |
| |
| } // anonymous namespace |
| } // namespace rtti_dump |
| |
| #endif // RTTI_DUMP |