llvm-project/lldb/source/Plugins/ExpressionParser/Go/GoUserExpression.cpp

757 lines
23 KiB
C++

//===-- GoUserExpression.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
#include <stdio.h>
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
// C++ Includes
#include <cstdlib>
#include <memory>
#include <string>
#include <vector>
// Other libraries and framework includes
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringMap.h"
// Project includes
#include "GoUserExpression.h"
#include "lldb/lldb-private.h"
#include "lldb/Core/ConstString.h"
#include "lldb/Core/DataBufferHeap.h"
#include "lldb/Core/DataEncoder.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Core/ValueObjectRegister.h"
#include "lldb/Expression/ExpressionVariable.h"
#include "lldb/Symbol/TypeList.h"
#include "lldb/Symbol/GoASTContext.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadPlan.h"
#include "lldb/Target/ThreadPlanCallUserExpression.h"
#include "Plugins/ExpressionParser/Go/GoAST.h"
#include "Plugins/ExpressionParser/Go/GoParser.h"
using namespace lldb_private;
using namespace lldb;
class GoUserExpression::GoInterpreter
{
public:
GoInterpreter(ExecutionContext &exe_ctx, const char *expr)
: m_exe_ctx(exe_ctx), m_frame(exe_ctx.GetFrameSP()), m_parser(expr)
{
if (m_frame)
{
const SymbolContext &ctx = m_frame->GetSymbolContext(eSymbolContextFunction);
ConstString fname = ctx.GetFunctionName();
if (fname.GetLength() > 0)
{
size_t dot = fname.GetStringRef().find('.');
if (dot != llvm::StringRef::npos)
m_package = llvm::StringRef(fname.AsCString(), dot);
}
}
}
void
set_use_dynamic(DynamicValueType use_dynamic)
{
m_use_dynamic = use_dynamic;
}
bool Parse();
lldb::ValueObjectSP Evaluate(ExecutionContext &exe_ctx);
lldb::ValueObjectSP EvaluateStatement(const GoASTStmt *s);
lldb::ValueObjectSP EvaluateExpr(const GoASTExpr *e);
ValueObjectSP
VisitBadExpr(const GoASTBadExpr *e)
{
m_parser.GetError(m_error);
return nullptr;
}
ValueObjectSP VisitParenExpr(const GoASTParenExpr *e);
ValueObjectSP VisitIdent(const GoASTIdent *e);
ValueObjectSP VisitStarExpr(const GoASTStarExpr *e);
ValueObjectSP VisitSelectorExpr(const GoASTSelectorExpr *e);
ValueObjectSP VisitBasicLit(const GoASTBasicLit *e);
ValueObjectSP VisitIndexExpr(const GoASTIndexExpr *e);
ValueObjectSP VisitUnaryExpr(const GoASTUnaryExpr *e);
ValueObjectSP VisitCallExpr(const GoASTCallExpr *e);
ValueObjectSP
VisitTypeAssertExpr(const GoASTTypeAssertExpr *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitBinaryExpr(const GoASTBinaryExpr *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitArrayType(const GoASTArrayType *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitChanType(const GoASTChanType *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitCompositeLit(const GoASTCompositeLit *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitEllipsis(const GoASTEllipsis *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitFuncType(const GoASTFuncType *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitFuncLit(const GoASTFuncLit *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitInterfaceType(const GoASTInterfaceType *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitKeyValueExpr(const GoASTKeyValueExpr *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitMapType(const GoASTMapType *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitSliceExpr(const GoASTSliceExpr *e)
{
return NotImplemented(e);
}
ValueObjectSP
VisitStructType(const GoASTStructType *e)
{
return NotImplemented(e);
}
CompilerType EvaluateType(const GoASTExpr *e);
Error &
error()
{
return m_error;
}
private:
std::nullptr_t
NotImplemented(const GoASTExpr *e)
{
m_error.SetErrorStringWithFormat("%s node not implemented", e->GetKindName());
return nullptr;
}
ExecutionContext m_exe_ctx;
lldb::StackFrameSP m_frame;
GoParser m_parser;
DynamicValueType m_use_dynamic;
Error m_error;
llvm::StringRef m_package;
std::vector<std::unique_ptr<GoASTStmt>> m_statements;
};
VariableSP
FindGlobalVariable(TargetSP target, llvm::Twine name)
{
ConstString fullname(name.str());
VariableList variable_list;
const bool append = true;
if (!target)
{
return nullptr;
}
const uint32_t match_count = target->GetImages().FindGlobalVariables(fullname, append, 1, variable_list);
if (match_count == 1)
{
return variable_list.GetVariableAtIndex(0);
}
return nullptr;
}
CompilerType
LookupType(TargetSP target, ConstString name)
{
if (!target)
return CompilerType();
SymbolContext sc;
TypeList type_list;
uint32_t num_matches = target->GetImages().FindTypes(sc, name, false, 2, type_list);
if (num_matches > 0)
{
return type_list.GetTypeAtIndex(0)->GetFullCompilerType();
}
return CompilerType();
}
GoUserExpression::GoUserExpression(ExecutionContextScope &exe_scope, const char *expr, const char *expr_prefix,
lldb::LanguageType language, ResultType desired_type,
const EvaluateExpressionOptions &options)
: UserExpression(exe_scope, expr, expr_prefix, language, desired_type, options)
{
}
bool
GoUserExpression::Parse(Stream &error_stream, ExecutionContext &exe_ctx, lldb_private::ExecutionPolicy execution_policy,
bool keep_result_in_memory, bool generate_debug_info)
{
InstallContext(exe_ctx);
m_interpreter.reset(new GoInterpreter(exe_ctx, GetUserText()));
if (m_interpreter->Parse())
return true;
const char *error_cstr = m_interpreter->error().AsCString();
if (error_cstr && error_cstr[0])
error_stream.Printf("error: %s\n", error_cstr);
else
error_stream.Printf("error: expression can't be interpreted or run\n");
return false;
}
lldb::ExpressionResults
GoUserExpression::Execute(Stream &error_stream, ExecutionContext &exe_ctx, const EvaluateExpressionOptions &options,
lldb::UserExpressionSP &shared_ptr_to_me, lldb::ExpressionVariableSP &result)
{
Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP));
lldb_private::ExecutionPolicy execution_policy = options.GetExecutionPolicy();
lldb::ExpressionResults execution_results = lldb::eExpressionSetupError;
Process *process = exe_ctx.GetProcessPtr();
Target *target = exe_ctx.GetTargetPtr();
if (target == nullptr || process == nullptr || process->GetState() != lldb::eStateStopped)
{
if (execution_policy == eExecutionPolicyAlways)
{
if (log)
log->Printf("== [GoUserExpression::Evaluate] Expression may not run, but is not constant ==");
error_stream.Printf("expression needed to run but couldn't");
return execution_results;
}
}
m_interpreter->set_use_dynamic(options.GetUseDynamic());
ValueObjectSP result_val_sp = m_interpreter->Evaluate(exe_ctx);
Error err = m_interpreter->error();
m_interpreter.reset();
if (!result_val_sp)
{
const char *error_cstr = err.AsCString();
if (error_cstr && error_cstr[0])
error_stream.Printf("error: %s\n", error_cstr);
else
error_stream.Printf("error: expression can't be interpreted or run\n");
return lldb::eExpressionDiscarded;
}
result.reset(new ExpressionVariable(ExpressionVariable::eKindGo));
result->m_live_sp = result->m_frozen_sp = result_val_sp;
result->m_flags |= ExpressionVariable::EVIsProgramReference;
PersistentExpressionState *pv = target->GetPersistentExpressionStateForLanguage(eLanguageTypeGo);
if (pv != nullptr)
{
result->SetName(pv->GetNextPersistentVariableName());
pv->AddVariable(result);
}
return lldb::eExpressionCompleted;
}
bool
GoUserExpression::GoInterpreter::Parse()
{
for (std::unique_ptr<GoASTStmt> stmt(m_parser.Statement()); stmt; stmt.reset(m_parser.Statement()))
{
if (m_parser.Failed())
break;
m_statements.emplace_back(std::move(stmt));
}
if (m_parser.Failed() || !m_parser.AtEOF())
m_parser.GetError(m_error);
return m_error.Success();
}
ValueObjectSP
GoUserExpression::GoInterpreter::Evaluate(ExecutionContext &exe_ctx)
{
m_exe_ctx = exe_ctx;
ValueObjectSP result;
for (const std::unique_ptr<GoASTStmt> &stmt : m_statements)
{
result = EvaluateStatement(stmt.get());
if (m_error.Fail())
return nullptr;
}
return result;
}
ValueObjectSP
GoUserExpression::GoInterpreter::EvaluateStatement(const lldb_private::GoASTStmt *stmt)
{
ValueObjectSP result;
switch (stmt->GetKind())
{
case GoASTNode::eBlockStmt:
{
const GoASTBlockStmt *block = llvm::cast<GoASTBlockStmt>(stmt);
for (size_t i = 0; i < block->NumList(); ++i)
result = EvaluateStatement(block->GetList(i));
break;
}
case GoASTNode::eBadStmt:
m_parser.GetError(m_error);
break;
case GoASTNode::eExprStmt:
{
const GoASTExprStmt *expr = llvm::cast<GoASTExprStmt>(stmt);
return EvaluateExpr(expr->GetX());
}
default:
m_error.SetErrorStringWithFormat("%s node not supported", stmt->GetKindName());
}
return result;
}
ValueObjectSP
GoUserExpression::GoInterpreter::EvaluateExpr(const lldb_private::GoASTExpr *e)
{
if (e)
return e->Visit<ValueObjectSP>(this);
return ValueObjectSP();
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitParenExpr(const lldb_private::GoASTParenExpr *e)
{
return EvaluateExpr(e->GetX());
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitIdent(const GoASTIdent *e)
{
ValueObjectSP val;
if (m_frame)
{
VariableSP var_sp;
std::string varname = e->GetName().m_value.str();
if (varname.size() > 1 && varname[0] == '$')
{
RegisterContextSP reg_ctx_sp = m_frame->GetRegisterContext();
const RegisterInfo *reg = reg_ctx_sp->GetRegisterInfoByName(varname.c_str() + 1);
if (reg)
{
std::string type;
switch (reg->encoding)
{
case lldb::eEncodingSint:
type.append("int");
break;
case lldb::eEncodingUint:
type.append("uint");
break;
case lldb::eEncodingIEEE754:
type.append("float");
break;
default:
m_error.SetErrorString("Invaild register encoding");
return nullptr;
}
switch (reg->byte_size)
{
case 8:
type.append("64");
break;
case 4:
type.append("32");
break;
case 2:
type.append("16");
break;
case 1:
type.append("8");
break;
default:
m_error.SetErrorString("Invaild register size");
return nullptr;
}
ValueObjectSP regVal =
ValueObjectRegister::Create(m_frame.get(), reg_ctx_sp, reg->kinds[eRegisterKindLLDB]);
CompilerType goType = LookupType(m_frame->CalculateTarget(), ConstString(type));
if (regVal)
{
regVal = regVal->Cast(goType);
return regVal;
}
}
m_error.SetErrorString("Invaild register name");
return nullptr;
}
VariableListSP var_list_sp(m_frame->GetInScopeVariableList(false));
if (var_list_sp)
{
var_sp = var_list_sp->FindVariable(ConstString(varname));
if (var_sp)
val = m_frame->GetValueObjectForFrameVariable(var_sp, m_use_dynamic);
else
{
// When a variable is on the heap instead of the stack, go records a variable
// '&x' instead of 'x'.
var_sp = var_list_sp->FindVariable(ConstString("&" + varname));
if (var_sp)
{
val = m_frame->GetValueObjectForFrameVariable(var_sp, m_use_dynamic);
if (val)
val = val->Dereference(m_error);
if (m_error.Fail())
return nullptr;
}
}
}
if (!val)
{
m_error.Clear();
TargetSP target = m_frame->CalculateTarget();
if (!target)
{
m_error.SetErrorString("No target");
return nullptr;
}
var_sp = FindGlobalVariable(target, m_package + "." + e->GetName().m_value);
if (var_sp)
return m_frame->TrackGlobalVariable(var_sp, m_use_dynamic);
}
}
if (!val)
m_error.SetErrorStringWithFormat("Unknown variable %s", e->GetName().m_value.str().c_str());
return val;
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitStarExpr(const GoASTStarExpr *e)
{
ValueObjectSP target = EvaluateExpr(e->GetX());
if (!target)
return nullptr;
return target->Dereference(m_error);
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitSelectorExpr(const lldb_private::GoASTSelectorExpr *e)
{
ValueObjectSP target = EvaluateExpr(e->GetX());
if (target)
{
if (target->GetCompilerType().IsPointerType())
{
target = target->Dereference(m_error);
if (m_error.Fail())
return nullptr;
}
ConstString field(e->GetSel()->GetName().m_value);
ValueObjectSP result = target->GetChildMemberWithName(field, true);
if (!result)
m_error.SetErrorStringWithFormat("Unknown child %s", field.AsCString());
return result;
}
if (const GoASTIdent *package = llvm::dyn_cast<GoASTIdent>(e->GetX()))
{
if (VariableSP global = FindGlobalVariable(m_exe_ctx.GetTargetSP(),
package->GetName().m_value + "." + e->GetSel()->GetName().m_value))
{
if (m_frame)
{
m_error.Clear();
return m_frame->GetValueObjectForFrameVariable(global, m_use_dynamic);
}
}
}
if (const GoASTBasicLit *packageLit = llvm::dyn_cast<GoASTBasicLit>(e->GetX()))
{
if (packageLit->GetValue().m_type == GoLexer::LIT_STRING)
{
std::string value = packageLit->GetValue().m_value.str();
value = value.substr(1, value.size() - 2);
if (VariableSP global =
FindGlobalVariable(m_exe_ctx.GetTargetSP(), value + "." + e->GetSel()->GetName().m_value))
{
if (m_frame)
{
m_error.Clear();
return m_frame->TrackGlobalVariable(global, m_use_dynamic);
}
}
}
}
// EvaluateExpr should have already set m_error.
return target;
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitBasicLit(const lldb_private::GoASTBasicLit *e)
{
std::string value = e->GetValue().m_value.str();
if (e->GetValue().m_type != GoLexer::LIT_INTEGER)
{
m_error.SetErrorStringWithFormat("Unsupported literal %s", value.c_str());
return nullptr;
}
errno = 0;
int64_t intvalue = strtol(value.c_str(), nullptr, 0);
if (errno != 0)
{
m_error.SetErrorToErrno();
return nullptr;
}
DataBufferSP buf(new DataBufferHeap(sizeof(intvalue), 0));
TargetSP target = m_exe_ctx.GetTargetSP();
if (!target)
{
m_error.SetErrorString("No target");
return nullptr;
}
ByteOrder order = target->GetArchitecture().GetByteOrder();
uint8_t addr_size = target->GetArchitecture().GetAddressByteSize();
DataEncoder enc(buf, order, addr_size);
enc.PutU64(0, static_cast<uint64_t>(intvalue));
DataExtractor data(buf, order, addr_size);
CompilerType type = LookupType(target, ConstString("int64"));
return ValueObject::CreateValueObjectFromData(nullptr, data, m_exe_ctx, type);
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitIndexExpr(const lldb_private::GoASTIndexExpr *e)
{
ValueObjectSP target = EvaluateExpr(e->GetX());
if (!target)
return nullptr;
ValueObjectSP index = EvaluateExpr(e->GetIndex());
if (!index)
return nullptr;
bool is_signed;
if (!index->GetCompilerType().IsIntegerType(is_signed))
{
m_error.SetErrorString("Unsupported index");
return nullptr;
}
size_t idx;
if (is_signed)
idx = index->GetValueAsSigned(0);
else
idx = index->GetValueAsUnsigned(0);
if (GoASTContext::IsGoSlice(target->GetCompilerType()))
{
target = target->GetStaticValue();
ValueObjectSP cap = target->GetChildMemberWithName(ConstString("cap"), true);
if (cap)
{
uint64_t capval = cap->GetValueAsUnsigned(0);
if (idx >= capval)
{
m_error.SetErrorStringWithFormat("Invalid index %" PRIu64 " , cap = %" PRIu64, uint64_t(idx), capval);
return nullptr;
}
}
target = target->GetChildMemberWithName(ConstString("array"), true);
if (target && m_use_dynamic != eNoDynamicValues)
{
ValueObjectSP dynamic = target->GetDynamicValue(m_use_dynamic);
if (dynamic)
target = dynamic;
}
if (!target)
return nullptr;
return target->GetSyntheticArrayMember(idx, true);
}
return target->GetChildAtIndex(idx, true);
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitUnaryExpr(const GoASTUnaryExpr *e)
{
ValueObjectSP x = EvaluateExpr(e->GetX());
if (!x)
return nullptr;
switch (e->GetOp())
{
case GoLexer::OP_AMP:
{
CompilerType type = x->GetCompilerType().GetPointerType();
uint64_t address = x->GetAddressOf();
return ValueObject::CreateValueObjectFromAddress(nullptr, address, m_exe_ctx, type);
}
case GoLexer::OP_PLUS:
return x;
default:
m_error.SetErrorStringWithFormat("Operator %s not supported",
GoLexer::LookupToken(e->GetOp()).str().c_str());
return nullptr;
}
}
CompilerType
GoUserExpression::GoInterpreter::EvaluateType(const GoASTExpr *e)
{
TargetSP target = m_exe_ctx.GetTargetSP();
if (auto *id = llvm::dyn_cast<GoASTIdent>(e))
{
CompilerType result = LookupType(target, ConstString(id->GetName().m_value));
if (result.IsValid())
return result;
std::string fullname = (m_package + "." + id->GetName().m_value).str();
result = LookupType(target, ConstString(fullname));
if (!result)
m_error.SetErrorStringWithFormat("Unknown type %s", fullname.c_str());
return result;
}
if (auto *sel = llvm::dyn_cast<GoASTSelectorExpr>(e))
{
std::string package;
if (auto *pkg_node = llvm::dyn_cast<GoASTIdent>(sel->GetX()))
{
package = pkg_node->GetName().m_value.str();
}
else if (auto *str_node = llvm::dyn_cast<GoASTBasicLit>(sel->GetX()))
{
if (str_node->GetValue().m_type == GoLexer::LIT_STRING)
{
package = str_node->GetValue().m_value.substr(1).str();
package.resize(package.length() - 1);
}
}
if (package.empty())
{
m_error.SetErrorStringWithFormat("Invalid %s in type expression", sel->GetX()->GetKindName());
return CompilerType();
}
std::string fullname = (package + "." + sel->GetSel()->GetName().m_value).str();
CompilerType result = LookupType(target, ConstString(fullname));
if (!result)
m_error.SetErrorStringWithFormat("Unknown type %s", fullname.c_str());
return result;
}
if (auto *star = llvm::dyn_cast<GoASTStarExpr>(e))
{
CompilerType elem = EvaluateType(star->GetX());
return elem.GetPointerType();
}
if (auto *paren = llvm::dyn_cast<GoASTParenExpr>(e))
return EvaluateType(paren->GetX());
if (auto *array = llvm::dyn_cast<GoASTArrayType>(e))
{
CompilerType elem = EvaluateType(array->GetElt());
}
m_error.SetErrorStringWithFormat("Invalid %s in type expression", e->GetKindName());
return CompilerType();
}
ValueObjectSP
GoUserExpression::GoInterpreter::VisitCallExpr(const lldb_private::GoASTCallExpr *e)
{
ValueObjectSP x = EvaluateExpr(e->GetFun());
if (x || e->NumArgs() != 1)
{
m_error.SetErrorStringWithFormat("Code execution not supported");
return nullptr;
}
m_error.Clear();
CompilerType type = EvaluateType(e->GetFun());
if (!type)
{
return nullptr;
}
ValueObjectSP value = EvaluateExpr(e->GetArgs(0));
if (!value)
return nullptr;
// TODO: Handle special conversions
return value->Cast(type);
}
GoPersistentExpressionState::GoPersistentExpressionState() : PersistentExpressionState(eKindGo)
{
}
ConstString
GoPersistentExpressionState::GetNextPersistentVariableName()
{
char name_cstr[256];
// We can't use the same variable format as clang.
::snprintf(name_cstr, sizeof(name_cstr), "$go%u", m_next_persistent_variable_id++);
ConstString name(name_cstr);
return name;
}
void
GoPersistentExpressionState::RemovePersistentVariable(lldb::ExpressionVariableSP variable)
{
RemoveVariable(variable);
const char *name = variable->GetName().AsCString();
if (*(name++) != '$')
return;
if (*(name++) != 'g')
return;
if (*(name++) != 'o')
return;
if (strtoul(name, nullptr, 0) == m_next_persistent_variable_id - 1)
m_next_persistent_variable_id--;
}