xref: /llvm-project-15.0.7/lldb/source/Commands/CommandObjectExpression.cpp (revision 1d3afba3)

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

#include "CommandObjectExpression.h"

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Interpreter/Args.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/InputReader.h"
#include "lldb/Core/ValueObjectVariable.h"
#include "lldb/Expression/ClangExpressionVariable.h"
#include "lldb/Expression/ClangUserExpression.h"
#include "lldb/Expression/ClangFunction.h"
#include "lldb/Expression/DWARFExpression.h"
#include "lldb/Host/Host.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Target/ObjCLanguageRuntime.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/Variable.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "llvm/ADT/StringRef.h"

using namespace lldb;
using namespace lldb_private;

CommandObjectExpression::CommandOptions::CommandOptions () :
    Options()
{
    // Keep only one place to reset the values to their defaults
    ResetOptionValues();
}


CommandObjectExpression::CommandOptions::~CommandOptions ()
{
}

Error
CommandObjectExpression::CommandOptions::SetOptionValue (int option_idx, const char *option_arg)
{
    Error error;

    char short_option = (char) m_getopt_table[option_idx].val;

    switch (short_option)
    {
      //case 'l':
      //if (language.SetLanguageFromCString (option_arg) == false)
      //{
      //    error.SetErrorStringWithFormat("Invalid language option argument '%s'.\n", option_arg);
      //}
      //break;

    case 'g':
        debug = true;
        break;

    case 'f':
        error = Args::StringToFormat(option_arg, format);
        break;

    case 'o':
        print_object = true;
        break;

    default:
        error.SetErrorStringWithFormat("Invalid short option character '%c'.\n", short_option);
        break;
    }

    return error;
}

void
CommandObjectExpression::CommandOptions::ResetOptionValues ()
{
    Options::ResetOptionValues();
    //language.Clear();
    debug = false;
    format = eFormatDefault;
    print_object = false;
    show_types = true;
    show_summary = true;
}

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

CommandObjectExpression::CommandObjectExpression (CommandInterpreter &interpreter) :
    CommandObject (interpreter,
                   "expression",
                   "Evaluate a C/ObjC/C++ expression in the current program context, using variables currently in scope.",
                   NULL),
    m_expr_line_count (0),
    m_expr_lines ()
{
  SetHelpLong(
"Examples: \n\
\n\
   expr my_struct->a = my_array[3] \n\
   expr -f bin -- (index * 8) + 5 \n\
   expr char c[] = \"foo\"; c[0]\n");

    CommandArgumentEntry arg;
    CommandArgumentData expression_arg;

    // Define the first (and only) variant of this arg.
    expression_arg.arg_type = eArgTypeExpression;
    expression_arg.arg_repetition = eArgRepeatPlain;

    // There is only one variant this argument could be; put it into the argument entry.
    arg.push_back (expression_arg);

    // Push the data for the first argument into the m_arguments vector.
    m_arguments.push_back (arg);
}

CommandObjectExpression::~CommandObjectExpression ()
{
}

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


bool
CommandObjectExpression::Execute
(
    Args& command,
    CommandReturnObject &result
)
{
    return false;
}


size_t
CommandObjectExpression::MultiLineExpressionCallback
(
    void *baton,
    InputReader &reader,
    lldb::InputReaderAction notification,
    const char *bytes,
    size_t bytes_len
)
{
    CommandObjectExpression *cmd_object_expr = (CommandObjectExpression *) baton;

    switch (notification)
    {
    case eInputReaderActivate:
        reader.GetDebugger().GetOutputStream().Printf("%s\n", "Enter expressions, then terminate with an empty line to evaluate:");
        // Fall through
    case eInputReaderReactivate:
        //if (out_fh)
        //    reader.GetDebugger().GetOutputStream().Printf ("%3u: ", cmd_object_expr->m_expr_line_count);
        break;

    case eInputReaderDeactivate:
        break;

    case eInputReaderGotToken:
        ++cmd_object_expr->m_expr_line_count;
        if (bytes && bytes_len)
        {
            cmd_object_expr->m_expr_lines.append (bytes, bytes_len + 1);
        }

        if (bytes_len == 0)
            reader.SetIsDone(true);
        //else if (out_fh && !reader->IsDone())
        //    ::fprintf (out_fh, "%3u: ", cmd_object_expr->m_expr_line_count);
        break;

    case eInputReaderDone:
        {
            bool bare = false;
            cmd_object_expr->EvaluateExpression (cmd_object_expr->m_expr_lines.c_str(),
                                                 bare,
                                                 reader.GetDebugger().GetOutputStream(),
                                                 reader.GetDebugger().GetErrorStream());
        }
        break;
    }

    return bytes_len;
}

bool
CommandObjectExpression::EvaluateExpression
(
    const char *expr,
    bool bare,
    Stream &output_stream,
    Stream &error_stream,
    CommandReturnObject *result
)
{
    if (!m_exe_ctx.process)
    {
        error_stream.Printf ("Execution context doesn't contain a process\n");
        return false;
    }

    if (!m_exe_ctx.process->GetDynamicCheckers())
    {
        DynamicCheckerFunctions *dynamic_checkers = new DynamicCheckerFunctions();

        StreamString install_errors;

        if (!dynamic_checkers->Install(install_errors, m_exe_ctx))
        {
            error_stream.Printf("Couldn't install dynamic checkers into the execution context: %s\n", install_errors.GetData());
            return false;
        }

        m_exe_ctx.process->SetDynamicCheckers(dynamic_checkers);
    }

    ClangUserExpression user_expression (expr);

    if (!user_expression.Parse (error_stream, m_exe_ctx))
    {
        error_stream.Printf ("Couldn't parse the expresssion\n");
        return false;
    }

    ClangExpressionVariable *expr_result = NULL;

    if (!user_expression.Execute (error_stream, m_exe_ctx, expr_result))
    {
        error_stream.Printf ("Couldn't execute the expresssion\n");
        return false;
    }

    if (expr_result)
    {
        // TODO: seems weird to get a pointer to a result object back from
        // a function. Do we own it? Feels like we do, but from looking at the
        // code we don't. Might be best to make this a reference and state
        // explicitly that we don't own it when we get a reference back from
        // the execute?
        lldb::ValueObjectSP valobj_sp (expr_result->GetExpressionResult (&m_exe_ctx));
        if (valobj_sp)
        {
            ValueObject::DumpValueObject (output_stream,
                                          m_exe_ctx.GetBestExecutionContextScope(),
                                          valobj_sp.get(),          // Variable object to dump
                                          expr_result->m_name.c_str(),// Root object name
                                          0,                        // Pointer depth to traverse (zero means stop at pointers)
                                          0,                        // Current depth, this is the top most, so zero...
                                          UINT32_MAX,               // Max depth to go when dumping concrete types, dump everything...
                                          m_options.show_types,     // Show types when dumping?
                                          false,                    // Show locations of variables, no since this is a host address which we don't care to see
                                          m_options.print_object,   // Print the objective C object?
                                          true);                    // Scope is already checked. Const results are always in scope.
            output_stream.EOL();
        }
        else
        {
            error_stream.PutCString ("Couldn't extract expression result");
        }
        if (result)
            result->SetStatus (eReturnStatusSuccessFinishResult);
    }
    else
    {
        if (result)
            result->SetStatus (eReturnStatusSuccessFinishNoResult);
    }

    return true;
}

bool
CommandObjectExpression::ExecuteRawCommandString
(
    const char *command,
    CommandReturnObject &result
)
{
    m_exe_ctx = m_interpreter.GetDebugger().GetExecutionContext();

    m_options.ResetOptionValues();

    const char * expr = NULL;

    if (command[0] == '\0')
    {
        m_expr_lines.clear();
        m_expr_line_count = 0;

        InputReaderSP reader_sp (new InputReader(m_interpreter.GetDebugger()));
        if (reader_sp)
        {
            Error err (reader_sp->Initialize (CommandObjectExpression::MultiLineExpressionCallback,
                                              this,                         // baton
                                              eInputReaderGranularityLine,  // token size, to pass to callback function
                                              NULL,                         // end token
                                              NULL,                         // prompt
                                              true));                       // echo input
            if (err.Success())
            {
                m_interpreter.GetDebugger().PushInputReader (reader_sp);
                result.SetStatus (eReturnStatusSuccessFinishNoResult);
            }
            else
            {
                result.AppendError (err.AsCString());
                result.SetStatus (eReturnStatusFailed);
            }
        }
        else
        {
            result.AppendError("out of memory");
            result.SetStatus (eReturnStatusFailed);
        }
        return result.Succeeded();
    }

    if (command[0] == '-')
    {
        // We have some options and these options MUST end with --.
        const char *end_options = NULL;
        const char *s = command;
        while (s && s[0])
        {
            end_options = ::strstr (s, "--");
            if (end_options)
            {
                end_options += 2; // Get past the "--"
                if (::isspace (end_options[0]))
                {
                    expr = end_options;
                    while (::isspace (*expr))
                        ++expr;
                    break;
                }
            }
            s = end_options;
        }

        if (end_options)
        {
            Args args (command, end_options - command);
            if (!ParseOptions (args, result))
                return false;
        }
    }

    if (expr == NULL)
        expr = command;

    if (EvaluateExpression (expr, false, result.GetOutputStream(), result.GetErrorStream(), &result))
        return true;

    result.SetStatus (eReturnStatusFailed);
    return false;
}

lldb::OptionDefinition
CommandObjectExpression::CommandOptions::g_option_table[] =
{
  //{ LLDB_OPT_SET_ALL, false, "language",   'l', required_argument, NULL, 0, "[c|c++|objc|objc++]",          "Sets the language to use when parsing the expression."},
//{ LLDB_OPT_SET_1, false, "format",     'f', required_argument, NULL, 0, "[ [bool|b] | [bin] | [char|c] | [oct|o] | [dec|i|d|u] | [hex|x] | [float|f] | [cstr|s] ]",  "Specify the format that the expression output should use."},
{ LLDB_OPT_SET_1, false, "format",             'f', required_argument, NULL, 0, eArgTypeExprFormat,  "Specify the format that the expression output should use."},
{ LLDB_OPT_SET_2, false, "object-description", 'o', no_argument,       NULL, 0, eArgTypeNone, "Print the object description of the value resulting from the expression"},
{ LLDB_OPT_SET_ALL, false, "debug",            'g', no_argument,       NULL, 0, eArgTypeNone, "Enable verbose debug logging of the expression parsing and evaluation."},
{ LLDB_OPT_SET_ALL, false, "use-ir",           'i', no_argument,       NULL, 0, eArgTypeNone, "[Temporary] Instructs the expression evaluator to use IR instead of ASTs."},
{ 0, false, NULL, 0, 0, NULL, NULL, eArgTypeNone, NULL }
};