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//===-- CommandObjectExpression.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 "llvm/ADT/StringRef.h"
#include "CommandObjectExpression.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Expression/REPL.h"
#include "lldb/Expression/UserExpression.h"
#include "lldb/Host/OptionParser.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Interpreter/OptionArgParser.h"
#include "lldb/Target/Language.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
using namespace lldb;
using namespace lldb_private;
CommandObjectExpression::CommandOptions::CommandOptions() : OptionGroup() {}
CommandObjectExpression::CommandOptions::~CommandOptions() = default;
static constexpr OptionEnumValueElement g_description_verbosity_type[] = {
{
eLanguageRuntimeDescriptionDisplayVerbosityCompact,
"compact",
"Only show the description string",
},
{
eLanguageRuntimeDescriptionDisplayVerbosityFull,
"full",
"Show the full output, including persistent variable's name and type",
},
};
static constexpr OptionEnumValues DescriptionVerbosityTypes() {
return OptionEnumValues(g_description_verbosity_type);
}
#define LLDB_OPTIONS_expression
#include "CommandOptions.inc"
Status CommandObjectExpression::CommandOptions::SetOptionValue(
uint32_t option_idx, llvm::StringRef option_arg,
ExecutionContext *execution_context) {
Status error;
const int short_option = GetDefinitions()[option_idx].short_option;
switch (short_option) {
case 'l':
language = Language::GetLanguageTypeFromString(option_arg);
if (language == eLanguageTypeUnknown)
error.SetErrorStringWithFormat(
"unknown language type: '%s' for expression",
option_arg.str().c_str());
break;
case 'a': {
bool success;
bool result;
result = OptionArgParser::ToBoolean(option_arg, true, &success);
if (!success)
error.SetErrorStringWithFormat(
"invalid all-threads value setting: \"%s\"",
option_arg.str().c_str());
else
try_all_threads = result;
} break;
case 'i': {
bool success;
bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
if (success)
ignore_breakpoints = tmp_value;
else
error.SetErrorStringWithFormat(
"could not convert \"%s\" to a boolean value.",
option_arg.str().c_str());
break;
}
case 'j': {
bool success;
bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
if (success)
allow_jit = tmp_value;
else
error.SetErrorStringWithFormat(
"could not convert \"%s\" to a boolean value.",
option_arg.str().c_str());
break;
}
case 't':
if (option_arg.getAsInteger(0, timeout)) {
timeout = 0;
error.SetErrorStringWithFormat("invalid timeout setting \"%s\"",
option_arg.str().c_str());
}
break;
case 'u': {
bool success;
bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
if (success)
unwind_on_error = tmp_value;
else
error.SetErrorStringWithFormat(
"could not convert \"%s\" to a boolean value.",
option_arg.str().c_str());
break;
}
case 'v':
if (option_arg.empty()) {
m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityFull;
break;
}
m_verbosity = (LanguageRuntimeDescriptionDisplayVerbosity)
OptionArgParser::ToOptionEnum(
option_arg, GetDefinitions()[option_idx].enum_values, 0, error);
if (!error.Success())
error.SetErrorStringWithFormat(
"unrecognized value for description-verbosity '%s'",
option_arg.str().c_str());
break;
case 'g':
debug = true;
unwind_on_error = false;
ignore_breakpoints = false;
break;
case 'p':
top_level = true;
break;
case 'X': {
bool success;
bool tmp_value = OptionArgParser::ToBoolean(option_arg, true, &success);
if (success)
auto_apply_fixits = tmp_value ? eLazyBoolYes : eLazyBoolNo;
else
error.SetErrorStringWithFormat(
"could not convert \"%s\" to a boolean value.",
option_arg.str().c_str());
break;
}
default:
llvm_unreachable("Unimplemented option");
}
return error;
}
void CommandObjectExpression::CommandOptions::OptionParsingStarting(
ExecutionContext *execution_context) {
auto process_sp =
execution_context ? execution_context->GetProcessSP() : ProcessSP();
if (process_sp) {
ignore_breakpoints = process_sp->GetIgnoreBreakpointsInExpressions();
unwind_on_error = process_sp->GetUnwindOnErrorInExpressions();
} else {
ignore_breakpoints = true;
unwind_on_error = true;
}
show_summary = true;
try_all_threads = true;
timeout = 0;
debug = false;
language = eLanguageTypeUnknown;
m_verbosity = eLanguageRuntimeDescriptionDisplayVerbosityCompact;
auto_apply_fixits = eLazyBoolCalculate;
top_level = false;
allow_jit = true;
}
llvm::ArrayRef<OptionDefinition>
CommandObjectExpression::CommandOptions::GetDefinitions() {
return llvm::makeArrayRef(g_expression_options);
}
CommandObjectExpression::CommandObjectExpression(
CommandInterpreter &interpreter)
: CommandObjectRaw(interpreter, "expression",
"Evaluate an expression on the current "
"thread. Displays any returned value "
"with LLDB's default formatting.",
"",
eCommandProcessMustBePaused | eCommandTryTargetAPILock),
IOHandlerDelegate(IOHandlerDelegate::Completion::Expression),
m_option_group(), m_format_options(eFormatDefault),
m_repl_option(LLDB_OPT_SET_1, false, "repl", 'r', "Drop into REPL", false,
true),
m_command_options(), m_expr_line_count(0), m_expr_lines() {
SetHelpLong(
R"(
Single and multi-line expressions:
)"
" The expression provided on the command line must be a complete expression \
with no newlines. To evaluate a multi-line expression, \
hit a return after an empty expression, and lldb will enter the multi-line expression editor. \
Hit return on an empty line to end the multi-line expression."
R"(
Timeouts:
)"
" If the expression can be evaluated statically (without running code) then it will be. \
Otherwise, by default the expression will run on the current thread with a short timeout: \
currently .25 seconds. If it doesn't return in that time, the evaluation will be interrupted \
and resumed with all threads running. You can use the -a option to disable retrying on all \
threads. You can use the -t option to set a shorter timeout."
R"(
User defined variables:
)"
" You can define your own variables for convenience or to be used in subsequent expressions. \
You define them the same way you would define variables in C. If the first character of \
your user defined variable is a $, then the variable's value will be available in future \
expressions, otherwise it will just be available in the current expression."
R"(
Continuing evaluation after a breakpoint:
)"
" If the \"-i false\" option is used, and execution is interrupted by a breakpoint hit, once \
you are done with your investigation, you can either remove the expression execution frames \
from the stack with \"thread return -x\" or if you are still interested in the expression result \
you can issue the \"continue\" command and the expression evaluation will complete and the \
expression result will be available using the \"thread.completed-expression\" key in the thread \
format."
R"(
Examples:
expr my_struct->a = my_array[3]
expr -f bin -- (index * 8) + 5
expr unsigned int $foo = 5
expr char c[] = \"foo\"; c[0])");
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);
// Add the "--format" and "--gdb-format"
m_option_group.Append(&m_format_options,
OptionGroupFormat::OPTION_GROUP_FORMAT |
OptionGroupFormat::OPTION_GROUP_GDB_FMT,
LLDB_OPT_SET_1);
m_option_group.Append(&m_command_options);
m_option_group.Append(&m_varobj_options, LLDB_OPT_SET_ALL,
LLDB_OPT_SET_1 | LLDB_OPT_SET_2);
m_option_group.Append(&m_repl_option, LLDB_OPT_SET_ALL, LLDB_OPT_SET_3);
m_option_group.Finalize();
}
CommandObjectExpression::~CommandObjectExpression() = default;
Options *CommandObjectExpression::GetOptions() { return &m_option_group; }
void CommandObjectExpression::HandleCompletion(CompletionRequest &request) {
EvaluateExpressionOptions options;
options.SetCoerceToId(m_varobj_options.use_objc);
options.SetLanguage(m_command_options.language);
options.SetExecutionPolicy(lldb_private::eExecutionPolicyNever);
options.SetAutoApplyFixIts(false);
options.SetGenerateDebugInfo(false);
ExecutionContext exe_ctx(m_interpreter.GetExecutionContext());
// Get out before we start doing things that expect a valid frame pointer.
if (exe_ctx.GetFramePtr() == nullptr)
return;
Target *exe_target = exe_ctx.GetTargetPtr();
Target &target = exe_target ? *exe_target : GetDummyTarget();
unsigned cursor_pos = request.GetRawCursorPos();
// Get the full user input including the suffix. The suffix is necessary
// as OptionsWithRaw will use it to detect if the cursor is cursor is in the
// argument part of in the raw input part of the arguments. If we cut of
// of the suffix then "expr -arg[cursor] --" would interpret the "-arg" as
// the raw input (as the "--" is hidden in the suffix).
llvm::StringRef code = request.GetRawLineWithUnusedSuffix();
const std::size_t original_code_size = code.size();
// Remove the first token which is 'expr' or some alias/abbreviation of that.
code = llvm::getToken(code).second.ltrim();
OptionsWithRaw args(code);
code = args.GetRawPart();
// The position where the expression starts in the command line.
assert(original_code_size >= code.size());
std::size_t raw_start = original_code_size - code.size();
// Check if the cursor is actually in the expression string, and if not, we
// exit.
// FIXME: We should complete the options here.
if (cursor_pos < raw_start)
return;
// Make the cursor_pos again relative to the start of the code string.
assert(cursor_pos >= raw_start);
cursor_pos -= raw_start;
auto language = exe_ctx.GetFrameRef().GetLanguage();
Status error;
lldb::UserExpressionSP expr(target.GetUserExpressionForLanguage(
code, llvm::StringRef(), language, UserExpression::eResultTypeAny,
options, nullptr, error));
if (error.Fail())
return;
expr->Complete(exe_ctx, request, cursor_pos);
}
static lldb_private::Status
CanBeUsedForElementCountPrinting(ValueObject &valobj) {
CompilerType type(valobj.GetCompilerType());
CompilerType pointee;
if (!type.IsPointerType(&pointee))
return Status("as it does not refer to a pointer");
if (pointee.IsVoidType())
return Status("as it refers to a pointer to void");
return Status();
}
EvaluateExpressionOptions
CommandObjectExpression::GetEvalOptions(const Target &target) {
EvaluateExpressionOptions options;
options.SetCoerceToId(m_varobj_options.use_objc);
options.SetUnwindOnError(m_command_options.unwind_on_error);
options.SetIgnoreBreakpoints(m_command_options.ignore_breakpoints);
options.SetKeepInMemory(true);
options.SetUseDynamic(m_varobj_options.use_dynamic);
options.SetTryAllThreads(m_command_options.try_all_threads);
options.SetDebug(m_command_options.debug);
options.SetLanguage(m_command_options.language);
options.SetExecutionPolicy(
m_command_options.allow_jit
? EvaluateExpressionOptions::default_execution_policy
: lldb_private::eExecutionPolicyNever);
bool auto_apply_fixits;
if (m_command_options.auto_apply_fixits == eLazyBoolCalculate)
auto_apply_fixits = target.GetEnableAutoApplyFixIts();
else
auto_apply_fixits = m_command_options.auto_apply_fixits == eLazyBoolYes;
options.SetAutoApplyFixIts(auto_apply_fixits);
options.SetRetriesWithFixIts(target.GetNumberOfRetriesWithFixits());
if (m_command_options.top_level)
options.SetExecutionPolicy(eExecutionPolicyTopLevel);
// If there is any chance we are going to stop and want to see what went
// wrong with our expression, we should generate debug info
if (!m_command_options.ignore_breakpoints ||
!m_command_options.unwind_on_error)
options.SetGenerateDebugInfo(true);
if (m_command_options.timeout > 0)
options.SetTimeout(std::chrono::microseconds(m_command_options.timeout));
else
options.SetTimeout(llvm::None);
return options;
}
bool CommandObjectExpression::EvaluateExpression(llvm::StringRef expr,
Stream &output_stream,
Stream &error_stream,
CommandReturnObject &result) {
// Don't use m_exe_ctx as this might be called asynchronously after the
// command object DoExecute has finished when doing multi-line expression
// that use an input reader...
ExecutionContext exe_ctx(m_interpreter.GetExecutionContext());
Target *exe_target = exe_ctx.GetTargetPtr();
Target &target = exe_target ? *exe_target : GetDummyTarget();
lldb::ValueObjectSP result_valobj_sp;
StackFrame *frame = exe_ctx.GetFramePtr();
if (m_command_options.top_level && !m_command_options.allow_jit) {
result.AppendErrorWithFormat(
"Can't disable JIT compilation for top-level expressions.\n");
return false;
}
const EvaluateExpressionOptions options = GetEvalOptions(target);
ExpressionResults success = target.EvaluateExpression(
expr, frame, result_valobj_sp, options, &m_fixed_expression);
// We only tell you about the FixIt if we applied it. The compiler errors
// will suggest the FixIt if it parsed.
if (!m_fixed_expression.empty() && target.GetEnableNotifyAboutFixIts()) {
error_stream.Printf(" Fix-it applied, fixed expression was: \n %s\n",
m_fixed_expression.c_str());
}
if (result_valobj_sp) {
Format format = m_format_options.GetFormat();
if (result_valobj_sp->GetError().Success()) {
if (format != eFormatVoid) {
if (format != eFormatDefault)
result_valobj_sp->SetFormat(format);
if (m_varobj_options.elem_count > 0) {
Status error(CanBeUsedForElementCountPrinting(*result_valobj_sp));
if (error.Fail()) {
result.AppendErrorWithFormat(
"expression cannot be used with --element-count %s\n",
error.AsCString(""));
return false;
}
}
DumpValueObjectOptions options(m_varobj_options.GetAsDumpOptions(
m_command_options.m_verbosity, format));
options.SetVariableFormatDisplayLanguage(
result_valobj_sp->GetPreferredDisplayLanguage());
result_valobj_sp->Dump(output_stream, options);
result.SetStatus(eReturnStatusSuccessFinishResult);
}
} else {
if (result_valobj_sp->GetError().GetError() ==
UserExpression::kNoResult) {
if (format != eFormatVoid && GetDebugger().GetNotifyVoid()) {
error_stream.PutCString("(void)\n");
}
result.SetStatus(eReturnStatusSuccessFinishResult);
} else {
const char *error_cstr = result_valobj_sp->GetError().AsCString();
if (error_cstr && error_cstr[0]) {
const size_t error_cstr_len = strlen(error_cstr);
const bool ends_with_newline = error_cstr[error_cstr_len - 1] == '\n';
if (strstr(error_cstr, "error:") != error_cstr)
error_stream.PutCString("error: ");
error_stream.Write(error_cstr, error_cstr_len);
if (!ends_with_newline)
error_stream.EOL();
} else {
error_stream.PutCString("error: unknown error\n");
}
result.SetStatus(eReturnStatusFailed);
}
}
}
return (success != eExpressionSetupError &&
success != eExpressionParseError);
}
void CommandObjectExpression::IOHandlerInputComplete(IOHandler &io_handler,
std::string &line) {
io_handler.SetIsDone(true);
// StreamSP output_stream =
// io_handler.GetDebugger().GetAsyncOutputStream();
// StreamSP error_stream = io_handler.GetDebugger().GetAsyncErrorStream();
StreamFileSP output_sp = io_handler.GetOutputStreamFileSP();
StreamFileSP error_sp = io_handler.GetErrorStreamFileSP();
CommandReturnObject return_obj(
GetCommandInterpreter().GetDebugger().GetUseColor());
EvaluateExpression(line.c_str(), *output_sp, *error_sp, return_obj);
if (output_sp)
output_sp->Flush();
if (error_sp)
error_sp->Flush();
}
bool CommandObjectExpression::IOHandlerIsInputComplete(IOHandler &io_handler,
StringList &lines) {
// An empty lines is used to indicate the end of input
const size_t num_lines = lines.GetSize();
if (num_lines > 0 && lines[num_lines - 1].empty()) {
// Remove the last empty line from "lines" so it doesn't appear in our
// resulting input and return true to indicate we are done getting lines
lines.PopBack();
return true;
}
return false;
}
void CommandObjectExpression::GetMultilineExpression() {
m_expr_lines.clear();
m_expr_line_count = 0;
Debugger &debugger = GetCommandInterpreter().GetDebugger();
bool color_prompt = debugger.GetUseColor();
const bool multiple_lines = true; // Get multiple lines
IOHandlerSP io_handler_sp(
new IOHandlerEditline(debugger, IOHandler::Type::Expression,
"lldb-expr", // Name of input reader for history
llvm::StringRef(), // No prompt
llvm::StringRef(), // Continuation prompt
multiple_lines, color_prompt,
1, // Show line numbers starting at 1
*this, nullptr));
StreamFileSP output_sp = io_handler_sp->GetOutputStreamFileSP();
if (output_sp) {
output_sp->PutCString(
"Enter expressions, then terminate with an empty line to evaluate:\n");
output_sp->Flush();
}
debugger.RunIOHandlerAsync(io_handler_sp);
}
static EvaluateExpressionOptions
GetExprOptions(ExecutionContext &ctx,
CommandObjectExpression::CommandOptions command_options) {
command_options.OptionParsingStarting(&ctx);
// Default certain settings for REPL regardless of the global settings.
command_options.unwind_on_error = false;
command_options.ignore_breakpoints = false;
command_options.debug = false;
EvaluateExpressionOptions expr_options;
expr_options.SetUnwindOnError(command_options.unwind_on_error);
expr_options.SetIgnoreBreakpoints(command_options.ignore_breakpoints);
expr_options.SetTryAllThreads(command_options.try_all_threads);
if (command_options.timeout > 0)
expr_options.SetTimeout(std::chrono::microseconds(command_options.timeout));
else
expr_options.SetTimeout(llvm::None);
return expr_options;
}
bool CommandObjectExpression::DoExecute(llvm::StringRef command,
CommandReturnObject &result) {
m_fixed_expression.clear();
auto exe_ctx = GetCommandInterpreter().GetExecutionContext();
m_option_group.NotifyOptionParsingStarting(&exe_ctx);
if (command.empty()) {
GetMultilineExpression();
return result.Succeeded();
}
OptionsWithRaw args(command);
llvm::StringRef expr = args.GetRawPart();
if (args.HasArgs()) {
if (!ParseOptionsAndNotify(args.GetArgs(), result, m_option_group, exe_ctx))
return false;
if (m_repl_option.GetOptionValue().GetCurrentValue()) {
Target &target = GetSelectedOrDummyTarget();
// Drop into REPL
m_expr_lines.clear();
m_expr_line_count = 0;
Debugger &debugger = target.GetDebugger();
// Check if the LLDB command interpreter is sitting on top of a REPL
// that launched it...
if (debugger.CheckTopIOHandlerTypes(IOHandler::Type::CommandInterpreter,
IOHandler::Type::REPL)) {
// the LLDB command interpreter is sitting on top of a REPL that
// launched it, so just say the command interpreter is done and
// fall back to the existing REPL
m_interpreter.GetIOHandler(false)->SetIsDone(true);
} else {
// We are launching the REPL on top of the current LLDB command
// interpreter, so just push one
bool initialize = false;
Status repl_error;
REPLSP repl_sp(target.GetREPL(repl_error, m_command_options.language,
nullptr, false));
if (!repl_sp) {
initialize = true;
repl_sp = target.GetREPL(repl_error, m_command_options.language,
nullptr, true);
if (!repl_error.Success()) {
result.SetError(repl_error);
return result.Succeeded();
}
}
if (repl_sp) {
if (initialize) {
repl_sp->SetEvaluateOptions(
GetExprOptions(exe_ctx, m_command_options));
repl_sp->SetFormatOptions(m_format_options);
repl_sp->SetValueObjectDisplayOptions(m_varobj_options);
}
IOHandlerSP io_handler_sp(repl_sp->GetIOHandler());
io_handler_sp->SetIsDone(false);
debugger.RunIOHandlerAsync(io_handler_sp);
} else {
repl_error.SetErrorStringWithFormat(
"Couldn't create a REPL for %s",
Language::GetNameForLanguageType(m_command_options.language));
result.SetError(repl_error);
return result.Succeeded();
}
}
}
// No expression following options
else if (expr.empty()) {
GetMultilineExpression();
return result.Succeeded();
}
}
Target &target = GetSelectedOrDummyTarget();
if (EvaluateExpression(expr, result.GetOutputStream(),
result.GetErrorStream(), result)) {
if (!m_fixed_expression.empty() && target.GetEnableNotifyAboutFixIts()) {
CommandHistory &history = m_interpreter.GetCommandHistory();
// FIXME: Can we figure out what the user actually typed (e.g. some alias
// for expr???)
// If we can it would be nice to show that.
std::string fixed_command("expression ");
if (args.HasArgs()) {
// Add in any options that might have been in the original command:
fixed_command.append(std::string(args.GetArgStringWithDelimiter()));
fixed_command.append(m_fixed_expression);
} else
fixed_command.append(m_fixed_expression);
history.AppendString(fixed_command);
}
return true;
}
result.SetStatus(eReturnStatusFailed);
return false;
}