StackFrameRecognizer.cpp

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//===-- StackFrameRecognizer.cpp ------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "lldb/Target/StackFrameRecognizer.h"
#include "lldb/Core/Module.h"
#include "lldb/Interpreter/ScriptInterpreter.h"
#include "lldb/Symbol/Symbol.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Utility/RegularExpression.h"
 
using namespace lldb;
using namespace lldb_private;
 
class ScriptedRecognizedStackFrame : public RecognizedStackFrame {
  bool m_hidden;
 
public:
  ScriptedRecognizedStackFrame(ValueObjectListSP args, bool hidden)
      : m_hidden(hidden) {
    m_arguments = std::move(args);
  }
  bool ShouldHide() override { return m_hidden; }
};
 
ScriptedStackFrameRecognizer::ScriptedStackFrameRecognizer(
    ScriptInterpreter *interpreter, const char *pclass)
    : m_interpreter(interpreter), m_python_class(pclass) {
  m_python_object_sp =
      m_interpreter->CreateFrameRecognizer(m_python_class.c_str());
}
 
RecognizedStackFrameSP
ScriptedStackFrameRecognizer::RecognizeFrame(lldb::StackFrameSP frame) {
  if (!m_python_object_sp || !m_interpreter)
    return RecognizedStackFrameSP();
 
  ValueObjectListSP args =
      m_interpreter->GetRecognizedArguments(m_python_object_sp, frame);
  auto args_synthesized = ValueObjectListSP(new ValueObjectList());
  if (args) {
    for (const auto &o : args->GetObjects())
      args_synthesized->Append(ValueObjectRecognizerSynthesizedValue::Create(
          *o, eValueTypeVariableArgument));
  }
 
  bool hidden = m_interpreter->ShouldHide(m_python_object_sp, frame);
 
  return RecognizedStackFrameSP(
      new ScriptedRecognizedStackFrame(args_synthesized, hidden));
}
 
void StackFrameRecognizerManager::BumpGeneration() {
  uint32_t n = m_generation;
  n = (n + 1) & ((1 << 16) - 1);
  m_generation = n;
}
 
void StackFrameRecognizerManager::AddRecognizer(
    StackFrameRecognizerSP recognizer, ConstString module,
    llvm::ArrayRef<ConstString> symbols, bool first_instruction_only) {
  m_recognizers.push_front({(uint32_t)m_recognizers.size(), recognizer, false,
                            module, RegularExpressionSP(), symbols,
                            RegularExpressionSP(), first_instruction_only});
  BumpGeneration();
}
 
void StackFrameRecognizerManager::AddRecognizer(
    StackFrameRecognizerSP recognizer, RegularExpressionSP module,
    RegularExpressionSP symbol, bool first_instruction_only) {
  m_recognizers.push_front({(uint32_t)m_recognizers.size(), recognizer, true,
                            ConstString(), module, std::vector<ConstString>(),
                            symbol, first_instruction_only});
  BumpGeneration();
}
 
void StackFrameRecognizerManager::ForEach(
    const std::function<void(uint32_t, std::string, std::string,
                             llvm::ArrayRef<ConstString>, bool)> &callback) {
  for (auto entry : m_recognizers) {
    if (entry.is_regexp) {
      std::string module_name;
      std::string symbol_name;
 
      if (entry.module_regexp)
        module_name = entry.module_regexp->GetText().str();
      if (entry.symbol_regexp)
        symbol_name = entry.symbol_regexp->GetText().str();
 
      callback(entry.recognizer_id, entry.recognizer->GetName(), module_name,
               llvm::ArrayRef(ConstString(symbol_name)), true);
 
    } else {
      callback(entry.recognizer_id, entry.recognizer->GetName(),
               entry.module.GetCString(), entry.symbols, false);
    }
  }
}
 
bool StackFrameRecognizerManager::RemoveRecognizerWithID(
    uint32_t recognizer_id) {
  if (recognizer_id >= m_recognizers.size())
    return false;
  auto found =
      llvm::find_if(m_recognizers, [recognizer_id](const RegisteredEntry &e) {
        return e.recognizer_id == recognizer_id;
      });
  if (found == m_recognizers.end())
    return false;
  m_recognizers.erase(found);
  BumpGeneration();
  return true;
}
 
void StackFrameRecognizerManager::RemoveAllRecognizers() {
  BumpGeneration();
  m_recognizers.clear();
}
 
StackFrameRecognizerSP
StackFrameRecognizerManager::GetRecognizerForFrame(StackFrameSP frame) {
  const SymbolContext &symctx = frame->GetSymbolContext(
      eSymbolContextModule | eSymbolContextFunction | eSymbolContextSymbol);
  ConstString function_name = symctx.GetFunctionName();
  ModuleSP module_sp = symctx.module_sp;
  if (!module_sp)
    return StackFrameRecognizerSP();
  ConstString module_name = module_sp->GetFileSpec().GetFilename();
  Symbol *symbol = symctx.symbol;
  if (!symbol)
    return StackFrameRecognizerSP();
  Address start_addr = symbol->GetAddress();
  Address current_addr = frame->GetFrameCodeAddress();
 
  for (auto entry : m_recognizers) {
    if (entry.module)
      if (entry.module != module_name)
        continue;
 
    if (entry.module_regexp)
      if (!entry.module_regexp->Execute(module_name.GetStringRef()))
        continue;
 
    if (!entry.symbols.empty())
      if (!llvm::is_contained(entry.symbols, function_name))
        continue;
 
    if (entry.symbol_regexp)
      if (!entry.symbol_regexp->Execute(function_name.GetStringRef()))
        continue;
 
    if (entry.first_instruction_only)
      if (start_addr != current_addr)
        continue;
 
    return entry.recognizer;
  }
  return StackFrameRecognizerSP();
}
 
RecognizedStackFrameSP
StackFrameRecognizerManager::RecognizeFrame(StackFrameSP frame) {
  auto recognizer = GetRecognizerForFrame(frame);
  if (!recognizer)
    return RecognizedStackFrameSP();
  return recognizer->RecognizeFrame(frame);
}