1//===-- ItaniumABILanguageRuntime.cpp -------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "ItaniumABILanguageRuntime.h"
10
11#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
12#include "lldb/Breakpoint/BreakpointLocation.h"
13#include "lldb/Core/Mangled.h"
14#include "lldb/Core/Module.h"
15#include "lldb/Core/PluginManager.h"
16#include "lldb/Core/ValueObject.h"
17#include "lldb/Core/ValueObjectMemory.h"
18#include "lldb/DataFormatters/FormattersHelpers.h"
19#include "lldb/Expression/DiagnosticManager.h"
20#include "lldb/Expression/FunctionCaller.h"
21#include "lldb/Interpreter/CommandObject.h"
22#include "lldb/Interpreter/CommandObjectMultiword.h"
23#include "lldb/Interpreter/CommandReturnObject.h"
24#include "lldb/Symbol/Symbol.h"
25#include "lldb/Symbol/SymbolFile.h"
26#include "lldb/Symbol/TypeList.h"
27#include "lldb/Target/Process.h"
28#include "lldb/Target/RegisterContext.h"
29#include "lldb/Target/SectionLoadList.h"
30#include "lldb/Target/StopInfo.h"
31#include "lldb/Target/Target.h"
32#include "lldb/Target/Thread.h"
33#include "lldb/Utility/ConstString.h"
34#include "lldb/Utility/LLDBLog.h"
35#include "lldb/Utility/Log.h"
36#include "lldb/Utility/Scalar.h"
37#include "lldb/Utility/Status.h"
38
39#include <vector>
40
41using namespace lldb;
42using namespace lldb_private;
43
44LLDB_PLUGIN_DEFINE_ADV(ItaniumABILanguageRuntime, CXXItaniumABI)
45
46static const char *vtable_demangled_prefix = "vtable for ";
47
48char ItaniumABILanguageRuntime::ID = 0;
49
50bool ItaniumABILanguageRuntime::CouldHaveDynamicValue(ValueObject &in_value) {
51  const bool check_cxx = true;
52  const bool check_objc = false;
53  return in_value.GetCompilerType().IsPossibleDynamicType(nullptr, check_cxx,
54                                                          check_objc);
55}
56
57TypeAndOrName ItaniumABILanguageRuntime::GetTypeInfo(
58    ValueObject &in_value, const VTableInfo &vtable_info) {
59  if (vtable_info.addr.IsSectionOffset()) {
60    // See if we have cached info for this type already
61    TypeAndOrName type_info = GetDynamicTypeInfo(vtable_info.addr);
62    if (type_info)
63      return type_info;
64
65    if (vtable_info.symbol) {
66      Log *log = GetLog(LLDBLog::Object);
67      llvm::StringRef symbol_name =
68          vtable_info.symbol->GetMangled().GetDemangledName().GetStringRef();
69      LLDB_LOGF(log,
70                "0x%16.16" PRIx64
71                ": static-type = '%s' has vtable symbol '%s'\n",
72                in_value.GetPointerValue(),
73                in_value.GetTypeName().GetCString(),
74                symbol_name.str().c_str());
75      // We are a C++ class, that's good.  Get the class name and look it
76      // up:
77      llvm::StringRef class_name = symbol_name;
78      class_name.consume_front(vtable_demangled_prefix);
79      // We know the class name is absolute, so tell FindTypes that by
80      // prefixing it with the root namespace:
81      std::string lookup_name("::");
82      lookup_name.append(class_name.data(), class_name.size());
83
84      type_info.SetName(class_name);
85      ConstString const_lookup_name(lookup_name);
86      TypeList class_types;
87      ModuleSP module_sp = vtable_info.symbol->CalculateSymbolContextModule();
88      // First look in the module that the vtable symbol came from and
89      // look for a single exact match.
90      TypeResults results;
91      TypeQuery query(const_lookup_name.GetStringRef(),
92                      TypeQueryOptions::e_exact_match |
93                          TypeQueryOptions::e_find_one);
94      if (module_sp) {
95        module_sp->FindTypes(query, results);
96        TypeSP type_sp = results.GetFirstType();
97        if (type_sp)
98          class_types.Insert(type_sp);
99      }
100
101      // If we didn't find a symbol, then move on to the entire module
102      // list in the target and get as many unique matches as possible
103      if (class_types.Empty()) {
104        query.SetFindOne(false);
105        m_process->GetTarget().GetImages().FindTypes(nullptr, query, results);
106        for (const auto &type_sp : results.GetTypeMap().Types())
107          class_types.Insert(type_sp);
108      }
109
110      lldb::TypeSP type_sp;
111      if (class_types.Empty()) {
112        LLDB_LOGF(log, "0x%16.16" PRIx64 ": is not dynamic\n",
113                  in_value.GetPointerValue());
114        return TypeAndOrName();
115      }
116      if (class_types.GetSize() == 1) {
117        type_sp = class_types.GetTypeAtIndex(0);
118        if (type_sp) {
119          if (TypeSystemClang::IsCXXClassType(
120                  type_sp->GetForwardCompilerType())) {
121            LLDB_LOGF(
122                log,
123                "0x%16.16" PRIx64
124                ": static-type = '%s' has dynamic type: uid={0x%" PRIx64
125                "}, type-name='%s'\n",
126                in_value.GetPointerValue(), in_value.GetTypeName().AsCString(),
127                type_sp->GetID(), type_sp->GetName().GetCString());
128            type_info.SetTypeSP(type_sp);
129          }
130        }
131      } else {
132        size_t i;
133        if (log) {
134          for (i = 0; i < class_types.GetSize(); i++) {
135            type_sp = class_types.GetTypeAtIndex(i);
136            if (type_sp) {
137              LLDB_LOGF(
138                  log,
139                  "0x%16.16" PRIx64
140                  ": static-type = '%s' has multiple matching dynamic "
141                  "types: uid={0x%" PRIx64 "}, type-name='%s'\n",
142                  in_value.GetPointerValue(),
143                  in_value.GetTypeName().AsCString(),
144                  type_sp->GetID(), type_sp->GetName().GetCString());
145            }
146          }
147        }
148
149        for (i = 0; i < class_types.GetSize(); i++) {
150          type_sp = class_types.GetTypeAtIndex(i);
151          if (type_sp) {
152            if (TypeSystemClang::IsCXXClassType(
153                    type_sp->GetForwardCompilerType())) {
154              LLDB_LOGF(
155                  log,
156                  "0x%16.16" PRIx64 ": static-type = '%s' has multiple "
157                  "matching dynamic types, picking "
158                  "this one: uid={0x%" PRIx64 "}, type-name='%s'\n",
159                  in_value.GetPointerValue(),
160                  in_value.GetTypeName().AsCString(),
161                  type_sp->GetID(), type_sp->GetName().GetCString());
162              type_info.SetTypeSP(type_sp);
163            }
164          }
165        }
166
167        if (log) {
168          LLDB_LOGF(log,
169                    "0x%16.16" PRIx64
170                    ": static-type = '%s' has multiple matching dynamic "
171                    "types, didn't find a C++ match\n",
172                    in_value.GetPointerValue(),
173                    in_value.GetTypeName().AsCString());
174        }
175      }
176      if (type_info)
177        SetDynamicTypeInfo(vtable_info.addr, type_info);
178      return type_info;
179    }
180  }
181  return TypeAndOrName();
182}
183
184llvm::Error ItaniumABILanguageRuntime::TypeHasVTable(CompilerType type) {
185  // Check to make sure the class has a vtable.
186  CompilerType original_type = type;
187  if (type.IsPointerOrReferenceType()) {
188    CompilerType pointee_type = type.GetPointeeType();
189    if (pointee_type)
190      type = pointee_type;
191  }
192
193  // Make sure this is a class or a struct first by checking the type class
194  // bitfield that gets returned.
195  if ((type.GetTypeClass() & (eTypeClassStruct | eTypeClassClass)) == 0) {
196    return llvm::createStringError(std::errc::invalid_argument,
197        "type \"%s\" is not a class or struct or a pointer to one",
198        original_type.GetTypeName().AsCString("<invalid>"));
199  }
200
201  // Check if the type has virtual functions by asking it if it is polymorphic.
202  if (!type.IsPolymorphicClass()) {
203    return llvm::createStringError(std::errc::invalid_argument,
204        "type \"%s\" doesn't have a vtable",
205        type.GetTypeName().AsCString("<invalid>"));
206  }
207  return llvm::Error::success();
208}
209
210// This function can accept both pointers or references to classes as well as
211// instances of classes. If you are using this function during dynamic type
212// detection, only valid ValueObjects that return true to
213// CouldHaveDynamicValue(...) should call this function and \a check_type
214// should be set to false. This function is also used by ValueObjectVTable
215// and is can pass in instances of classes which is not suitable for dynamic
216// type detection, these cases should pass true for \a check_type.
217llvm::Expected<LanguageRuntime::VTableInfo>
218 ItaniumABILanguageRuntime::GetVTableInfo(ValueObject &in_value,
219                                          bool check_type) {
220
221  CompilerType type = in_value.GetCompilerType();
222  if (check_type) {
223    if (llvm::Error err = TypeHasVTable(type))
224      return std::move(err);
225  }
226  ExecutionContext exe_ctx(in_value.GetExecutionContextRef());
227  Process *process = exe_ctx.GetProcessPtr();
228  if (process == nullptr)
229    return llvm::createStringError(std::errc::invalid_argument,
230                                   "invalid process");
231
232  AddressType address_type;
233  lldb::addr_t original_ptr = LLDB_INVALID_ADDRESS;
234  if (type.IsPointerOrReferenceType())
235    original_ptr = in_value.GetPointerValue(&address_type);
236  else
237    original_ptr = in_value.GetAddressOf(/*scalar_is_load_address=*/true,
238                                         &address_type);
239  if (original_ptr == LLDB_INVALID_ADDRESS || address_type != eAddressTypeLoad)
240    return llvm::createStringError(std::errc::invalid_argument,
241                                   "failed to get the address of the value");
242
243  Status error;
244  lldb::addr_t vtable_load_addr =
245      process->ReadPointerFromMemory(original_ptr, error);
246
247  if (!error.Success() || vtable_load_addr == LLDB_INVALID_ADDRESS)
248    return llvm::createStringError(std::errc::invalid_argument,
249        "failed to read vtable pointer from memory at 0x%" PRIx64,
250        original_ptr);
251
252  // The vtable load address can have authentication bits with
253  // AArch64 targets on Darwin.
254  vtable_load_addr = process->FixDataAddress(vtable_load_addr);
255
256  // Find the symbol that contains the "vtable_load_addr" address
257  Address vtable_addr;
258  if (!process->GetTarget().ResolveLoadAddress(vtable_load_addr, vtable_addr))
259    return llvm::createStringError(std::errc::invalid_argument,
260                                   "failed to resolve vtable pointer 0x%"
261                                   PRIx64 "to a section", vtable_load_addr);
262
263  // Check our cache first to see if we already have this info
264  {
265    std::lock_guard<std::mutex> locker(m_mutex);
266    auto pos = m_vtable_info_map.find(vtable_addr);
267    if (pos != m_vtable_info_map.end())
268      return pos->second;
269  }
270
271  Symbol *symbol = vtable_addr.CalculateSymbolContextSymbol();
272  if (symbol == nullptr)
273    return llvm::createStringError(std::errc::invalid_argument,
274                                   "no symbol found for 0x%" PRIx64,
275                                   vtable_load_addr);
276  llvm::StringRef name = symbol->GetMangled().GetDemangledName().GetStringRef();
277  if (name.starts_with(vtable_demangled_prefix)) {
278    VTableInfo info = {vtable_addr, symbol};
279    std::lock_guard<std::mutex> locker(m_mutex);
280    auto pos = m_vtable_info_map[vtable_addr] = info;
281    return info;
282  }
283  return llvm::createStringError(std::errc::invalid_argument,
284      "symbol found that contains 0x%" PRIx64 " is not a vtable symbol",
285      vtable_load_addr);
286}
287
288bool ItaniumABILanguageRuntime::GetDynamicTypeAndAddress(
289    ValueObject &in_value, lldb::DynamicValueType use_dynamic,
290    TypeAndOrName &class_type_or_name, Address &dynamic_address,
291    Value::ValueType &value_type) {
292  // For Itanium, if the type has a vtable pointer in the object, it will be at
293  // offset 0 in the object.  That will point to the "address point" within the
294  // vtable (not the beginning of the vtable.)  We can then look up the symbol
295  // containing this "address point" and that symbol's name demangled will
296  // contain the full class name. The second pointer above the "address point"
297  // is the "offset_to_top".  We'll use that to get the start of the value
298  // object which holds the dynamic type.
299  //
300
301  class_type_or_name.Clear();
302  value_type = Value::ValueType::Scalar;
303
304  if (!CouldHaveDynamicValue(in_value))
305    return false;
306
307  // Check if we have a vtable pointer in this value. If we don't it will
308  // return an error, else it will return a valid resolved address. We don't
309  // want GetVTableInfo to check the type since we accept void * as a possible
310  // dynamic type and that won't pass the type check. We already checked the
311  // type above in CouldHaveDynamicValue(...).
312  llvm::Expected<VTableInfo> vtable_info_or_err =
313      GetVTableInfo(in_value, /*check_type=*/false);
314  if (!vtable_info_or_err) {
315    llvm::consumeError(vtable_info_or_err.takeError());
316    return false;
317  }
318
319  const VTableInfo &vtable_info = vtable_info_or_err.get();
320  class_type_or_name = GetTypeInfo(in_value, vtable_info);
321
322  if (!class_type_or_name)
323    return false;
324
325  CompilerType type = class_type_or_name.GetCompilerType();
326  // There can only be one type with a given name, so we've just found
327  // duplicate definitions, and this one will do as well as any other. We
328  // don't consider something to have a dynamic type if it is the same as
329  // the static type.  So compare against the value we were handed.
330  if (!type)
331    return true;
332
333  if (TypeSystemClang::AreTypesSame(in_value.GetCompilerType(), type)) {
334    // The dynamic type we found was the same type, so we don't have a
335    // dynamic type here...
336    return false;
337  }
338
339  // The offset_to_top is two pointers above the vtable pointer.
340  Target &target = m_process->GetTarget();
341  const addr_t vtable_load_addr = vtable_info.addr.GetLoadAddress(&target);
342  if (vtable_load_addr == LLDB_INVALID_ADDRESS)
343    return false;
344  const uint32_t addr_byte_size = m_process->GetAddressByteSize();
345  const lldb::addr_t offset_to_top_location =
346      vtable_load_addr - 2 * addr_byte_size;
347  // Watch for underflow, offset_to_top_location should be less than
348  // vtable_load_addr
349  if (offset_to_top_location >= vtable_load_addr)
350    return false;
351  Status error;
352  const int64_t offset_to_top = m_process->ReadSignedIntegerFromMemory(
353      offset_to_top_location, addr_byte_size, INT64_MIN, error);
354
355  if (offset_to_top == INT64_MIN)
356    return false;
357  // So the dynamic type is a value that starts at offset_to_top above
358  // the original address.
359  lldb::addr_t dynamic_addr = in_value.GetPointerValue() + offset_to_top;
360  if (!m_process->GetTarget().ResolveLoadAddress(
361          dynamic_addr, dynamic_address)) {
362    dynamic_address.SetRawAddress(dynamic_addr);
363  }
364  return true;
365}
366
367TypeAndOrName ItaniumABILanguageRuntime::FixUpDynamicType(
368    const TypeAndOrName &type_and_or_name, ValueObject &static_value) {
369  CompilerType static_type(static_value.GetCompilerType());
370  Flags static_type_flags(static_type.GetTypeInfo());
371
372  TypeAndOrName ret(type_and_or_name);
373  if (type_and_or_name.HasType()) {
374    // The type will always be the type of the dynamic object.  If our parent's
375    // type was a pointer, then our type should be a pointer to the type of the
376    // dynamic object.  If a reference, then the original type should be
377    // okay...
378    CompilerType orig_type = type_and_or_name.GetCompilerType();
379    CompilerType corrected_type = orig_type;
380    if (static_type_flags.AllSet(eTypeIsPointer))
381      corrected_type = orig_type.GetPointerType();
382    else if (static_type_flags.AllSet(eTypeIsReference))
383      corrected_type = orig_type.GetLValueReferenceType();
384    ret.SetCompilerType(corrected_type);
385  } else {
386    // If we are here we need to adjust our dynamic type name to include the
387    // correct & or * symbol
388    std::string corrected_name(type_and_or_name.GetName().GetCString());
389    if (static_type_flags.AllSet(eTypeIsPointer))
390      corrected_name.append(" *");
391    else if (static_type_flags.AllSet(eTypeIsReference))
392      corrected_name.append(" &");
393    // the parent type should be a correctly pointer'ed or referenc'ed type
394    ret.SetCompilerType(static_type);
395    ret.SetName(corrected_name.c_str());
396  }
397  return ret;
398}
399
400// Static Functions
401LanguageRuntime *
402ItaniumABILanguageRuntime::CreateInstance(Process *process,
403                                          lldb::LanguageType language) {
404  // FIXME: We have to check the process and make sure we actually know that
405  // this process supports
406  // the Itanium ABI.
407  if (language == eLanguageTypeC_plus_plus ||
408      language == eLanguageTypeC_plus_plus_03 ||
409      language == eLanguageTypeC_plus_plus_11 ||
410      language == eLanguageTypeC_plus_plus_14)
411    return new ItaniumABILanguageRuntime(process);
412  else
413    return nullptr;
414}
415
416class CommandObjectMultiwordItaniumABI_Demangle : public CommandObjectParsed {
417public:
418  CommandObjectMultiwordItaniumABI_Demangle(CommandInterpreter &interpreter)
419      : CommandObjectParsed(
420            interpreter, "demangle", "Demangle a C++ mangled name.",
421            "language cplusplus demangle [<mangled-name> ...]") {
422    CommandArgumentEntry arg;
423    CommandArgumentData index_arg;
424
425    // Define the first (and only) variant of this arg.
426    index_arg.arg_type = eArgTypeSymbol;
427    index_arg.arg_repetition = eArgRepeatPlus;
428
429    // There is only one variant this argument could be; put it into the
430    // argument entry.
431    arg.push_back(index_arg);
432
433    // Push the data for the first argument into the m_arguments vector.
434    m_arguments.push_back(arg);
435  }
436
437  ~CommandObjectMultiwordItaniumABI_Demangle() override = default;
438
439protected:
440  void DoExecute(Args &command, CommandReturnObject &result) override {
441    bool demangled_any = false;
442    bool error_any = false;
443    for (auto &entry : command.entries()) {
444      if (entry.ref().empty())
445        continue;
446
447      // the actual Mangled class should be strict about this, but on the
448      // command line if you're copying mangled names out of 'nm' on Darwin,
449      // they will come out with an extra underscore - be willing to strip this
450      // on behalf of the user.   This is the moral equivalent of the -_/-n
451      // options to c++filt
452      auto name = entry.ref();
453      if (name.starts_with("__Z"))
454        name = name.drop_front();
455
456      Mangled mangled(name);
457      if (mangled.GuessLanguage() == lldb::eLanguageTypeC_plus_plus) {
458        ConstString demangled(mangled.GetDisplayDemangledName());
459        demangled_any = true;
460        result.AppendMessageWithFormat("%s ---> %s\n", entry.c_str(),
461                                       demangled.GetCString());
462      } else {
463        error_any = true;
464        result.AppendErrorWithFormat("%s is not a valid C++ mangled name\n",
465                                     entry.ref().str().c_str());
466      }
467    }
468
469    result.SetStatus(
470        error_any ? lldb::eReturnStatusFailed
471                  : (demangled_any ? lldb::eReturnStatusSuccessFinishResult
472                                   : lldb::eReturnStatusSuccessFinishNoResult));
473  }
474};
475
476class CommandObjectMultiwordItaniumABI : public CommandObjectMultiword {
477public:
478  CommandObjectMultiwordItaniumABI(CommandInterpreter &interpreter)
479      : CommandObjectMultiword(
480            interpreter, "cplusplus",
481            "Commands for operating on the C++ language runtime.",
482            "cplusplus <subcommand> [<subcommand-options>]") {
483    LoadSubCommand(
484        "demangle",
485        CommandObjectSP(
486            new CommandObjectMultiwordItaniumABI_Demangle(interpreter)));
487  }
488
489  ~CommandObjectMultiwordItaniumABI() override = default;
490};
491
492void ItaniumABILanguageRuntime::Initialize() {
493  PluginManager::RegisterPlugin(
494      GetPluginNameStatic(), "Itanium ABI for the C++ language", CreateInstance,
495      [](CommandInterpreter &interpreter) -> lldb::CommandObjectSP {
496        return CommandObjectSP(
497            new CommandObjectMultiwordItaniumABI(interpreter));
498      });
499}
500
501void ItaniumABILanguageRuntime::Terminate() {
502  PluginManager::UnregisterPlugin(CreateInstance);
503}
504
505BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(
506    const BreakpointSP &bkpt, bool catch_bp, bool throw_bp) {
507  return CreateExceptionResolver(bkpt, catch_bp, throw_bp, false);
508}
509
510BreakpointResolverSP ItaniumABILanguageRuntime::CreateExceptionResolver(
511    const BreakpointSP &bkpt, bool catch_bp, bool throw_bp,
512    bool for_expressions) {
513  // One complication here is that most users DON'T want to stop at
514  // __cxa_allocate_expression, but until we can do anything better with
515  // predicting unwinding the expression parser does.  So we have two forms of
516  // the exception breakpoints, one for expressions that leaves out
517  // __cxa_allocate_exception, and one that includes it. The
518  // SetExceptionBreakpoints does the latter, the CreateExceptionBreakpoint in
519  // the runtime the former.
520  static const char *g_catch_name = "__cxa_begin_catch";
521  static const char *g_throw_name1 = "__cxa_throw";
522  static const char *g_throw_name2 = "__cxa_rethrow";
523  static const char *g_exception_throw_name = "__cxa_allocate_exception";
524  std::vector<const char *> exception_names;
525  exception_names.reserve(4);
526  if (catch_bp)
527    exception_names.push_back(g_catch_name);
528
529  if (throw_bp) {
530    exception_names.push_back(g_throw_name1);
531    exception_names.push_back(g_throw_name2);
532  }
533
534  if (for_expressions)
535    exception_names.push_back(g_exception_throw_name);
536
537  BreakpointResolverSP resolver_sp(new BreakpointResolverName(
538      bkpt, exception_names.data(), exception_names.size(),
539      eFunctionNameTypeBase, eLanguageTypeUnknown, 0, eLazyBoolNo));
540
541  return resolver_sp;
542}
543
544lldb::SearchFilterSP ItaniumABILanguageRuntime::CreateExceptionSearchFilter() {
545  Target &target = m_process->GetTarget();
546
547  FileSpecList filter_modules;
548  if (target.GetArchitecture().GetTriple().getVendor() == llvm::Triple::Apple) {
549    // Limit the number of modules that are searched for these breakpoints for
550    // Apple binaries.
551    filter_modules.EmplaceBack("libc++abi.dylib");
552    filter_modules.EmplaceBack("libSystem.B.dylib");
553    filter_modules.EmplaceBack("libc++abi.1.0.dylib");
554    filter_modules.EmplaceBack("libc++abi.1.dylib");
555  }
556  return target.GetSearchFilterForModuleList(&filter_modules);
557}
558
559lldb::BreakpointSP ItaniumABILanguageRuntime::CreateExceptionBreakpoint(
560    bool catch_bp, bool throw_bp, bool for_expressions, bool is_internal) {
561  Target &target = m_process->GetTarget();
562  FileSpecList filter_modules;
563  BreakpointResolverSP exception_resolver_sp =
564      CreateExceptionResolver(nullptr, catch_bp, throw_bp, for_expressions);
565  SearchFilterSP filter_sp(CreateExceptionSearchFilter());
566  const bool hardware = false;
567  const bool resolve_indirect_functions = false;
568  return target.CreateBreakpoint(filter_sp, exception_resolver_sp, is_internal,
569                                 hardware, resolve_indirect_functions);
570}
571
572void ItaniumABILanguageRuntime::SetExceptionBreakpoints() {
573  if (!m_process)
574    return;
575
576  const bool catch_bp = false;
577  const bool throw_bp = true;
578  const bool is_internal = true;
579  const bool for_expressions = true;
580
581  // For the exception breakpoints set by the Expression parser, we'll be a
582  // little more aggressive and stop at exception allocation as well.
583
584  if (m_cxx_exception_bp_sp) {
585    m_cxx_exception_bp_sp->SetEnabled(true);
586  } else {
587    m_cxx_exception_bp_sp = CreateExceptionBreakpoint(
588        catch_bp, throw_bp, for_expressions, is_internal);
589    if (m_cxx_exception_bp_sp)
590      m_cxx_exception_bp_sp->SetBreakpointKind("c++ exception");
591  }
592}
593
594void ItaniumABILanguageRuntime::ClearExceptionBreakpoints() {
595  if (!m_process)
596    return;
597
598  if (m_cxx_exception_bp_sp) {
599    m_cxx_exception_bp_sp->SetEnabled(false);
600  }
601}
602
603bool ItaniumABILanguageRuntime::ExceptionBreakpointsAreSet() {
604  return m_cxx_exception_bp_sp && m_cxx_exception_bp_sp->IsEnabled();
605}
606
607bool ItaniumABILanguageRuntime::ExceptionBreakpointsExplainStop(
608    lldb::StopInfoSP stop_reason) {
609  if (!m_process)
610    return false;
611
612  if (!stop_reason || stop_reason->GetStopReason() != eStopReasonBreakpoint)
613    return false;
614
615  uint64_t break_site_id = stop_reason->GetValue();
616  return m_process->GetBreakpointSiteList().StopPointSiteContainsBreakpoint(
617      break_site_id, m_cxx_exception_bp_sp->GetID());
618}
619
620ValueObjectSP ItaniumABILanguageRuntime::GetExceptionObjectForThread(
621    ThreadSP thread_sp) {
622  if (!thread_sp->SafeToCallFunctions())
623    return {};
624
625  TypeSystemClangSP scratch_ts_sp =
626      ScratchTypeSystemClang::GetForTarget(m_process->GetTarget());
627  if (!scratch_ts_sp)
628    return {};
629
630  CompilerType voidstar =
631      scratch_ts_sp->GetBasicType(eBasicTypeVoid).GetPointerType();
632
633  DiagnosticManager diagnostics;
634  ExecutionContext exe_ctx;
635  EvaluateExpressionOptions options;
636
637  options.SetUnwindOnError(true);
638  options.SetIgnoreBreakpoints(true);
639  options.SetStopOthers(true);
640  options.SetTimeout(m_process->GetUtilityExpressionTimeout());
641  options.SetTryAllThreads(false);
642  thread_sp->CalculateExecutionContext(exe_ctx);
643
644  const ModuleList &modules = m_process->GetTarget().GetImages();
645  SymbolContextList contexts;
646  SymbolContext context;
647
648  modules.FindSymbolsWithNameAndType(
649      ConstString("__cxa_current_exception_type"), eSymbolTypeCode, contexts);
650  contexts.GetContextAtIndex(0, context);
651  if (!context.symbol) {
652    return {};
653  }
654  Address addr = context.symbol->GetAddress();
655
656  Status error;
657  FunctionCaller *function_caller =
658      m_process->GetTarget().GetFunctionCallerForLanguage(
659          eLanguageTypeC, voidstar, addr, ValueList(), "caller", error);
660
661  ExpressionResults func_call_ret;
662  Value results;
663  func_call_ret = function_caller->ExecuteFunction(exe_ctx, nullptr, options,
664                                                   diagnostics, results);
665  if (func_call_ret != eExpressionCompleted || !error.Success()) {
666    return ValueObjectSP();
667  }
668
669  size_t ptr_size = m_process->GetAddressByteSize();
670  addr_t result_ptr = results.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
671  addr_t exception_addr =
672      m_process->ReadPointerFromMemory(result_ptr - ptr_size, error);
673
674  if (!error.Success()) {
675    return ValueObjectSP();
676  }
677
678  lldb_private::formatters::InferiorSizedWord exception_isw(exception_addr,
679                                                            *m_process);
680  ValueObjectSP exception = ValueObject::CreateValueObjectFromData(
681      "exception", exception_isw.GetAsData(m_process->GetByteOrder()), exe_ctx,
682      voidstar);
683  ValueObjectSP dyn_exception
684      = exception->GetDynamicValue(eDynamicDontRunTarget);
685  // If we succeed in making a dynamic value, return that:
686  if (dyn_exception)
687     return dyn_exception;
688
689  return exception;
690}
691
692TypeAndOrName ItaniumABILanguageRuntime::GetDynamicTypeInfo(
693    const lldb_private::Address &vtable_addr) {
694  std::lock_guard<std::mutex> locker(m_mutex);
695  DynamicTypeCache::const_iterator pos = m_dynamic_type_map.find(vtable_addr);
696  if (pos == m_dynamic_type_map.end())
697    return TypeAndOrName();
698  else
699    return pos->second;
700}
701
702void ItaniumABILanguageRuntime::SetDynamicTypeInfo(
703    const lldb_private::Address &vtable_addr, const TypeAndOrName &type_info) {
704  std::lock_guard<std::mutex> locker(m_mutex);
705  m_dynamic_type_map[vtable_addr] = type_info;
706}
707