llvm-project/lldb/source/Commands/CommandObjectExpression.cpp
Sean Callanan 92adcac9ec Implemented a major overhaul of the way variables are handled
by LLDB.  Instead of being materialized into the input structure
passed to the expression, variables are left in place and pointers
to them are materialzied into the structure.  Variables not resident
in memory (notably, registers) get temporary memory regions allocated
for them.

Persistent variables are the most complex part of this, because they
are made in various ways and there are different expectations about
their lifetime.  Persistent variables now have flags indicating their
status and what the expectations for longevity are.  They can be
marked as residing in target memory permanently -- this is the
default for result variables from expressions entered on the command
line and for explicitly declared persistent variables (but more on
that below).  Other result variables have their memory freed.

Some major improvements resulting from this include being able to
properly take the address of variables, better and cleaner support
for functions that return references, and cleaner C++ support in
general.  One problem that remains is the problem of explicitly
declared persistent variables; I have not yet implemented the code
that makes references to them into indirect references, so currently
materialization and dematerialization of these variables is broken.

llvm-svn: 123371
2011-01-13 08:53:35 +00:00

391 lines
13 KiB
C++

//===-- 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 "CommandObjectThread.h" // For DisplayThreadInfo.
#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;
case 'u':
bool success;
unwind_on_error = Args::StringToBoolean(option_arg, true, &success);
if (!success)
error.SetErrorStringWithFormat("Could not convert \"%s\" to a boolean value.", option_arg);
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;
unwind_on_error = true;
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 eInputReaderInterrupt:
cmd_object_expr->m_expr_lines.clear();
reader.SetIsDone (true);
reader.GetDebugger().GetOutputStream().Printf("%s\n", "Expression evaluation cancelled.");
break;
case eInputReaderEndOfFile:
reader.SetIsDone (true);
break;
case eInputReaderDone:
if (cmd_object_expr->m_expr_lines.size() > 0)
{
cmd_object_expr->EvaluateExpression (cmd_object_expr->m_expr_lines.c_str(),
reader.GetDebugger().GetOutputStream(),
reader.GetDebugger().GetErrorStream());
}
break;
}
return bytes_len;
}
bool
CommandObjectExpression::EvaluateExpression
(
const char *expr,
Stream &output_stream,
Stream &error_stream,
CommandReturnObject *result
)
{
if (m_exe_ctx.target)
{
lldb::ValueObjectSP result_valobj_sp;
lldb::ExecutionResults exe_results;
bool keep_in_memory = true;
exe_results = m_exe_ctx.target->EvaluateExpression(expr, m_exe_ctx.frame, m_options.unwind_on_error, keep_in_memory, result_valobj_sp);
if (exe_results == eExecutionInterrupted && !m_options.unwind_on_error)
{
if (m_exe_ctx.thread)
lldb_private::DisplayThreadInfo (m_interpreter, result->GetOutputStream(), m_exe_ctx.thread, false, true);
else
lldb_private::DisplayThreadsInfo (m_interpreter, &m_exe_ctx, *result, true, true);
}
if (result_valobj_sp)
{
if (result_valobj_sp->GetError().Success())
{
if (m_options.format != eFormatDefault)
result_valobj_sp->SetFormat (m_options.format);
ValueObject::DumpValueObject (output_stream,
m_exe_ctx.GetBestExecutionContextScope(),
result_valobj_sp.get(), // Variable object to dump
result_valobj_sp->GetName().GetCString(),// 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.
false); // Don't flatten output
if (result)
result->SetStatus (eReturnStatusSuccessFinishResult);
}
else
{
error_stream.PutCString(result_valobj_sp->GetError().AsCString());
if (result)
result->SetStatus (eReturnStatusFailed);
}
}
}
else
{
error_stream.Printf ("error: invalid execution context for expression\n");
return false;
}
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, 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, "unwind-on-error", 'u', required_argument, NULL, 0, eArgTypeBoolean, "Clean up program state if the expression causes a crash, breakpoint hit or signal."},
{ 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 }
};