llvm-project/lldb/source/Commands/CommandObjectArgs.cpp

//===-- CommandObjectArgs.cpp -----------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "CommandObjectArgs.h"
#include "Plugins/ExpressionParser/Clang/ClangExpressionVariable.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/Value.h"
#include "lldb/Host/Host.h"
#include "lldb/Interpreter/Args.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/Variable.h"
#include "lldb/Target/ABI.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"

using namespace lldb;
using namespace lldb_private;

// This command is a toy.  I'm just using it to have a way to construct the
// arguments to
// calling functions.
//

CommandObjectArgs::CommandOptions::CommandOptions(
    CommandInterpreter &interpreter)
    : Options() {
  // Keep only one place to reset the values to their defaults
  OptionParsingStarting(nullptr);
}

CommandObjectArgs::CommandOptions::~CommandOptions() = default;

Error CommandObjectArgs::CommandOptions::SetOptionValue(
    uint32_t option_idx, const char *option_arg,
    ExecutionContext *execution_context) {
  Error error;

  const int short_option = m_getopt_table[option_idx].val;
  error.SetErrorStringWithFormat("invalid short option character '%c'",
                                 short_option);

  return error;
}

void CommandObjectArgs::CommandOptions::OptionParsingStarting(
    ExecutionContext *execution_context) {}

const OptionDefinition *CommandObjectArgs::CommandOptions::GetDefinitions() {
  return g_option_table;
}

CommandObjectArgs::CommandObjectArgs(CommandInterpreter &interpreter)
    : CommandObjectParsed(interpreter, "args",
                          "When stopped at the start of a function, reads "
                          "function arguments of type (u?)int(8|16|32|64)_t, "
                          "(void|char)*",
                          "args"),
      m_options(interpreter) {}

CommandObjectArgs::~CommandObjectArgs() = default;

Options *CommandObjectArgs::GetOptions() { return &m_options; }

bool CommandObjectArgs::DoExecute(Args &args, CommandReturnObject &result) {
  ConstString target_triple;

  Process *process = m_exe_ctx.GetProcessPtr();
  if (!process) {
    result.AppendError("Args found no process.");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  const ABI *abi = process->GetABI().get();
  if (!abi) {
    result.AppendError("The current process has no ABI.");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  const size_t num_args = args.GetArgumentCount();
  size_t arg_index;

  if (!num_args) {
    result.AppendError("args requires at least one argument");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  Thread *thread = m_exe_ctx.GetThreadPtr();

  if (!thread) {
    result.AppendError("args found no thread.");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  lldb::StackFrameSP thread_cur_frame = thread->GetSelectedFrame();
  if (!thread_cur_frame) {
    result.AppendError("The current thread has no current frame.");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  ModuleSP thread_module_sp(
      thread_cur_frame->GetFrameCodeAddress().GetModule());
  if (!thread_module_sp) {
    result.AppendError("The PC has no associated module.");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  TypeSystem *type_system =
      thread_module_sp->GetTypeSystemForLanguage(eLanguageTypeC);
  if (type_system == nullptr) {
    result.AppendError("Unable to create C type system.");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  ValueList value_list;

  for (arg_index = 0; arg_index < num_args; ++arg_index) {
    const char *arg_type_cstr = args.GetArgumentAtIndex(arg_index);
    Value value;
    value.SetValueType(Value::eValueTypeScalar);
    CompilerType compiler_type;

    char *int_pos;
    if ((int_pos = strstr(const_cast<char *>(arg_type_cstr), "int"))) {
      Encoding encoding = eEncodingSint;

      int width = 0;

      if (int_pos > arg_type_cstr + 1) {
        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
        result.SetStatus(eReturnStatusFailed);
        return false;
      }
      if (int_pos == arg_type_cstr + 1 && arg_type_cstr[0] != 'u') {
        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
        result.SetStatus(eReturnStatusFailed);
        return false;
      }
      if (arg_type_cstr[0] == 'u') {
        encoding = eEncodingUint;
      }

      char *width_pos = int_pos + 3;

      if (!strcmp(width_pos, "8_t"))
        width = 8;
      else if (!strcmp(width_pos, "16_t"))
        width = 16;
      else if (!strcmp(width_pos, "32_t"))
        width = 32;
      else if (!strcmp(width_pos, "64_t"))
        width = 64;
      else {
        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
        result.SetStatus(eReturnStatusFailed);
        return false;
      }
      compiler_type =
          type_system->GetBuiltinTypeForEncodingAndBitSize(encoding, width);

      if (!compiler_type.IsValid()) {
        result.AppendErrorWithFormat(
            "Couldn't get Clang type for format %s (%s integer, width %d).\n",
            arg_type_cstr, (encoding == eEncodingSint ? "signed" : "unsigned"),
            width);

        result.SetStatus(eReturnStatusFailed);
        return false;
      }
    } else if (strchr(arg_type_cstr, '*')) {
      if (!strcmp(arg_type_cstr, "void*"))
        compiler_type =
            type_system->GetBasicTypeFromAST(eBasicTypeVoid).GetPointerType();
      else if (!strcmp(arg_type_cstr, "char*"))
        compiler_type =
            type_system->GetBasicTypeFromAST(eBasicTypeChar).GetPointerType();
      else {
        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
        result.SetStatus(eReturnStatusFailed);
        return false;
      }
    } else {
      result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
      result.SetStatus(eReturnStatusFailed);
      return false;
    }

    value.SetCompilerType(compiler_type);
    value_list.PushValue(value);
  }

  if (!abi->GetArgumentValues(*thread, value_list)) {
    result.AppendError("Couldn't get argument values");
    result.SetStatus(eReturnStatusFailed);
    return false;
  }

  result.GetOutputStream().Printf("Arguments : \n");

  for (arg_index = 0; arg_index < num_args; ++arg_index) {
    result.GetOutputStream().Printf("%" PRIu64 " (%s): ", (uint64_t)arg_index,
                                    args.GetArgumentAtIndex(arg_index));
    value_list.GetValueAtIndex(arg_index)->Dump(&result.GetOutputStream());
    result.GetOutputStream().Printf("\n");
  }

  return result.Succeeded();
}

OptionDefinition CommandObjectArgs::CommandOptions::g_option_table[] = {
    // clang-format off
  {LLDB_OPT_SET_1, false, "debug", 'g', OptionParser::eNoArgument, nullptr, nullptr, 0, eArgTypeNone, "Enable verbose debug logging of the expression parsing and evaluation."},
  {0, false, nullptr, 0, 0, nullptr, nullptr, 0, eArgTypeNone, nullptr}
    // clang-format on
};