Files
clang-p2996/lldb/source/Symbol/Variable.cpp
Adrian Prantl 0642cd768b [lldb] Turn lldb_private::Status into a value type. (#106163)
This patch removes all of the Set.* methods from Status.

This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.

This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()

Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form

`    ResultTy DoFoo(Status& error)
`
to

`    llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?

The interesting changes are in Status.h and Status.cpp, all other
changes are mostly

` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.
2024-08-27 10:59:31 -07:00

727 lines
24 KiB
C++

//===-- Variable.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 "lldb/Symbol/Variable.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectVariable.h"
#include "lldb/Symbol/Block.h"
#include "lldb/Symbol/CompileUnit.h"
#include "lldb/Symbol/CompilerDecl.h"
#include "lldb/Symbol/CompilerDeclContext.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/SymbolFile.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Symbol/TypeSystem.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/ABI.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/RegularExpression.h"
#include "lldb/Utility/Stream.h"
#include "llvm/ADT/Twine.h"
using namespace lldb;
using namespace lldb_private;
Variable::Variable(lldb::user_id_t uid, const char *name, const char *mangled,
const lldb::SymbolFileTypeSP &symfile_type_sp,
ValueType scope, SymbolContextScope *context,
const RangeList &scope_range, Declaration *decl_ptr,
const DWARFExpressionList &location_list, bool external,
bool artificial, bool location_is_constant_data,
bool static_member)
: UserID(uid), m_name(name), m_mangled(ConstString(mangled)),
m_symfile_type_sp(symfile_type_sp), m_scope(scope),
m_owner_scope(context), m_scope_range(scope_range),
m_declaration(decl_ptr), m_location_list(location_list), m_external(external),
m_artificial(artificial), m_loc_is_const_data(location_is_constant_data),
m_static_member(static_member) {}
Variable::~Variable() = default;
lldb::LanguageType Variable::GetLanguage() const {
lldb::LanguageType lang = m_mangled.GuessLanguage();
if (lang != lldb::eLanguageTypeUnknown)
return lang;
if (auto *func = m_owner_scope->CalculateSymbolContextFunction()) {
if ((lang = func->GetLanguage()) != lldb::eLanguageTypeUnknown)
return lang;
} else if (auto *comp_unit =
m_owner_scope->CalculateSymbolContextCompileUnit()) {
if ((lang = comp_unit->GetLanguage()) != lldb::eLanguageTypeUnknown)
return lang;
}
return lldb::eLanguageTypeUnknown;
}
ConstString Variable::GetName() const {
ConstString name = m_mangled.GetName();
if (name)
return name;
return m_name;
}
ConstString Variable::GetUnqualifiedName() const { return m_name; }
bool Variable::NameMatches(ConstString name) const {
if (m_name == name)
return true;
SymbolContext variable_sc;
m_owner_scope->CalculateSymbolContext(&variable_sc);
return m_mangled.NameMatches(name);
}
bool Variable::NameMatches(const RegularExpression &regex) const {
if (regex.Execute(m_name.AsCString()))
return true;
if (m_mangled)
return m_mangled.NameMatches(regex);
return false;
}
Type *Variable::GetType() {
if (m_symfile_type_sp)
return m_symfile_type_sp->GetType();
return nullptr;
}
void Variable::Dump(Stream *s, bool show_context) const {
s->Printf("%p: ", static_cast<const void *>(this));
s->Indent();
*s << "Variable" << (const UserID &)*this;
if (m_name)
*s << ", name = \"" << m_name << "\"";
if (m_symfile_type_sp) {
Type *type = m_symfile_type_sp->GetType();
if (type) {
s->Format(", type = {{{0:x-16}} {1} (", type->GetID(), type);
type->DumpTypeName(s);
s->PutChar(')');
}
}
if (m_scope != eValueTypeInvalid) {
s->PutCString(", scope = ");
switch (m_scope) {
case eValueTypeVariableGlobal:
s->PutCString(m_external ? "global" : "static");
break;
case eValueTypeVariableArgument:
s->PutCString("parameter");
break;
case eValueTypeVariableLocal:
s->PutCString("local");
break;
case eValueTypeVariableThreadLocal:
s->PutCString("thread local");
break;
default:
s->AsRawOstream() << "??? (" << m_scope << ')';
}
}
if (show_context && m_owner_scope != nullptr) {
s->PutCString(", context = ( ");
m_owner_scope->DumpSymbolContext(s);
s->PutCString(" )");
}
bool show_fullpaths = false;
m_declaration.Dump(s, show_fullpaths);
if (m_location_list.IsValid()) {
s->PutCString(", location = ");
ABISP abi;
if (m_owner_scope) {
ModuleSP module_sp(m_owner_scope->CalculateSymbolContextModule());
if (module_sp)
abi = ABI::FindPlugin(ProcessSP(), module_sp->GetArchitecture());
}
m_location_list.GetDescription(s, lldb::eDescriptionLevelBrief, abi.get());
}
if (m_external)
s->PutCString(", external");
if (m_artificial)
s->PutCString(", artificial");
s->EOL();
}
bool Variable::DumpDeclaration(Stream *s, bool show_fullpaths,
bool show_module) {
bool dumped_declaration_info = false;
if (m_owner_scope) {
SymbolContext sc;
m_owner_scope->CalculateSymbolContext(&sc);
sc.block = nullptr;
sc.line_entry.Clear();
bool show_inlined_frames = false;
const bool show_function_arguments = true;
const bool show_function_name = true;
dumped_declaration_info = sc.DumpStopContext(
s, nullptr, Address(), show_fullpaths, show_module, show_inlined_frames,
show_function_arguments, show_function_name);
if (sc.function)
s->PutChar(':');
}
if (m_declaration.DumpStopContext(s, false))
dumped_declaration_info = true;
return dumped_declaration_info;
}
size_t Variable::MemorySize() const { return sizeof(Variable); }
CompilerDeclContext Variable::GetDeclContext() {
Type *type = GetType();
if (type)
return type->GetSymbolFile()->GetDeclContextContainingUID(GetID());
return CompilerDeclContext();
}
CompilerDecl Variable::GetDecl() {
Type *type = GetType();
return type ? type->GetSymbolFile()->GetDeclForUID(GetID()) : CompilerDecl();
}
void Variable::CalculateSymbolContext(SymbolContext *sc) {
if (m_owner_scope) {
m_owner_scope->CalculateSymbolContext(sc);
sc->variable = this;
} else
sc->Clear(false);
}
bool Variable::LocationIsValidForFrame(StackFrame *frame) {
if (frame) {
Function *function =
frame->GetSymbolContext(eSymbolContextFunction).function;
if (function) {
TargetSP target_sp(frame->CalculateTarget());
addr_t loclist_base_load_addr =
function->GetAddressRange().GetBaseAddress().GetLoadAddress(
target_sp.get());
if (loclist_base_load_addr == LLDB_INVALID_ADDRESS)
return false;
// It is a location list. We just need to tell if the location list
// contains the current address when converted to a load address
return m_location_list.ContainsAddress(
loclist_base_load_addr,
frame->GetFrameCodeAddressForSymbolication().GetLoadAddress(
target_sp.get()));
}
}
return false;
}
bool Variable::LocationIsValidForAddress(const Address &address) {
// Be sure to resolve the address to section offset prior to calling this
// function.
if (address.IsSectionOffset()) {
// We need to check if the address is valid for both scope range and value
// range.
// Empty scope range means block range.
bool valid_in_scope_range =
GetScopeRange().IsEmpty() || GetScopeRange().FindEntryThatContains(
address.GetFileAddress()) != nullptr;
if (!valid_in_scope_range)
return false;
SymbolContext sc;
CalculateSymbolContext(&sc);
if (sc.module_sp == address.GetModule()) {
// Is the variable is described by a single location?
if (m_location_list.IsAlwaysValidSingleExpr()) {
// Yes it is, the location is valid.
return true;
}
if (sc.function) {
addr_t loclist_base_file_addr =
sc.function->GetAddressRange().GetBaseAddress().GetFileAddress();
if (loclist_base_file_addr == LLDB_INVALID_ADDRESS)
return false;
// It is a location list. We just need to tell if the location list
// contains the current address when converted to a load address
return m_location_list.ContainsAddress(loclist_base_file_addr,
address.GetFileAddress());
}
}
}
return false;
}
bool Variable::IsInScope(StackFrame *frame) {
switch (m_scope) {
case eValueTypeRegister:
case eValueTypeRegisterSet:
return frame != nullptr;
case eValueTypeConstResult:
case eValueTypeVariableGlobal:
case eValueTypeVariableStatic:
case eValueTypeVariableThreadLocal:
return true;
case eValueTypeVariableArgument:
case eValueTypeVariableLocal:
if (frame) {
// We don't have a location list, we just need to see if the block that
// this variable was defined in is currently
Block *deepest_frame_block =
frame->GetSymbolContext(eSymbolContextBlock).block;
if (deepest_frame_block) {
SymbolContext variable_sc;
CalculateSymbolContext(&variable_sc);
// Check for static or global variable defined at the compile unit
// level that wasn't defined in a block
if (variable_sc.block == nullptr)
return true;
// Check if the variable is valid in the current block
if (variable_sc.block != deepest_frame_block &&
!variable_sc.block->Contains(deepest_frame_block))
return false;
// If no scope range is specified then it means that the scope is the
// same as the scope of the enclosing lexical block.
if (m_scope_range.IsEmpty())
return true;
addr_t file_address = frame->GetFrameCodeAddress().GetFileAddress();
return m_scope_range.FindEntryThatContains(file_address) != nullptr;
}
}
break;
default:
break;
}
return false;
}
Status Variable::GetValuesForVariableExpressionPath(
llvm::StringRef variable_expr_path, ExecutionContextScope *scope,
GetVariableCallback callback, void *baton, VariableList &variable_list,
ValueObjectList &valobj_list) {
Status error;
if (!callback || variable_expr_path.empty()) {
error = Status::FromErrorString("unknown error");
return error;
}
switch (variable_expr_path.front()) {
case '*':
error = Variable::GetValuesForVariableExpressionPath(
variable_expr_path.drop_front(), scope, callback, baton, variable_list,
valobj_list);
if (error.Fail()) {
error = Status::FromErrorString("unknown error");
return error;
}
for (uint32_t i = 0; i < valobj_list.GetSize();) {
Status tmp_error;
ValueObjectSP valobj_sp(
valobj_list.GetValueObjectAtIndex(i)->Dereference(tmp_error));
if (tmp_error.Fail()) {
variable_list.RemoveVariableAtIndex(i);
valobj_list.RemoveValueObjectAtIndex(i);
} else {
valobj_list.SetValueObjectAtIndex(i, valobj_sp);
++i;
}
}
return error;
case '&': {
error = Variable::GetValuesForVariableExpressionPath(
variable_expr_path.drop_front(), scope, callback, baton, variable_list,
valobj_list);
if (error.Success()) {
for (uint32_t i = 0; i < valobj_list.GetSize();) {
Status tmp_error;
ValueObjectSP valobj_sp(
valobj_list.GetValueObjectAtIndex(i)->AddressOf(tmp_error));
if (tmp_error.Fail()) {
variable_list.RemoveVariableAtIndex(i);
valobj_list.RemoveValueObjectAtIndex(i);
} else {
valobj_list.SetValueObjectAtIndex(i, valobj_sp);
++i;
}
}
} else {
error = Status::FromErrorString("unknown error");
}
return error;
} break;
default: {
static RegularExpression g_regex(
llvm::StringRef("^([A-Za-z_:][A-Za-z_0-9:]*)(.*)"));
llvm::SmallVector<llvm::StringRef, 2> matches;
variable_list.Clear();
if (!g_regex.Execute(variable_expr_path, &matches)) {
error = Status::FromErrorStringWithFormatv(
"unable to extract a variable name from '{0}'", variable_expr_path);
return error;
}
std::string variable_name = matches[1].str();
if (!callback(baton, variable_name.c_str(), variable_list)) {
error = Status::FromErrorString("unknown error");
return error;
}
uint32_t i = 0;
while (i < variable_list.GetSize()) {
VariableSP var_sp(variable_list.GetVariableAtIndex(i));
ValueObjectSP valobj_sp;
if (!var_sp) {
variable_list.RemoveVariableAtIndex(i);
continue;
}
ValueObjectSP variable_valobj_sp(
ValueObjectVariable::Create(scope, var_sp));
if (!variable_valobj_sp) {
variable_list.RemoveVariableAtIndex(i);
continue;
}
llvm::StringRef variable_sub_expr_path =
variable_expr_path.drop_front(variable_name.size());
if (!variable_sub_expr_path.empty()) {
valobj_sp = variable_valobj_sp->GetValueForExpressionPath(
variable_sub_expr_path);
if (!valobj_sp) {
error = Status::FromErrorStringWithFormatv(
"invalid expression path '{0}' for variable '{1}'",
variable_sub_expr_path, var_sp->GetName().GetCString());
variable_list.RemoveVariableAtIndex(i);
continue;
}
} else {
// Just the name of a variable with no extras
valobj_sp = variable_valobj_sp;
}
valobj_list.Append(valobj_sp);
++i;
}
if (variable_list.GetSize() > 0) {
error.Clear();
return error;
}
} break;
}
error = Status::FromErrorString("unknown error");
return error;
}
bool Variable::DumpLocations(Stream *s, const Address &address) {
SymbolContext sc;
CalculateSymbolContext(&sc);
ABISP abi;
if (m_owner_scope) {
ModuleSP module_sp(m_owner_scope->CalculateSymbolContextModule());
if (module_sp)
abi = ABI::FindPlugin(ProcessSP(), module_sp->GetArchitecture());
}
const addr_t file_addr = address.GetFileAddress();
if (sc.function) {
addr_t loclist_base_file_addr =
sc.function->GetAddressRange().GetBaseAddress().GetFileAddress();
if (loclist_base_file_addr == LLDB_INVALID_ADDRESS)
return false;
return m_location_list.DumpLocations(s, eDescriptionLevelBrief,
loclist_base_file_addr, file_addr,
abi.get());
}
return false;
}
static void PrivateAutoComplete(
StackFrame *frame, llvm::StringRef partial_path,
const llvm::Twine
&prefix_path, // Anything that has been resolved already will be in here
const CompilerType &compiler_type, CompletionRequest &request);
static void PrivateAutoCompleteMembers(
StackFrame *frame, const std::string &partial_member_name,
llvm::StringRef partial_path,
const llvm::Twine
&prefix_path, // Anything that has been resolved already will be in here
const CompilerType &compiler_type, CompletionRequest &request) {
// We are in a type parsing child members
const uint32_t num_bases = compiler_type.GetNumDirectBaseClasses();
if (num_bases > 0) {
for (uint32_t i = 0; i < num_bases; ++i) {
CompilerType base_class_type =
compiler_type.GetDirectBaseClassAtIndex(i, nullptr);
PrivateAutoCompleteMembers(frame, partial_member_name, partial_path,
prefix_path,
base_class_type.GetCanonicalType(), request);
}
}
const uint32_t num_vbases = compiler_type.GetNumVirtualBaseClasses();
if (num_vbases > 0) {
for (uint32_t i = 0; i < num_vbases; ++i) {
CompilerType vbase_class_type =
compiler_type.GetVirtualBaseClassAtIndex(i, nullptr);
PrivateAutoCompleteMembers(frame, partial_member_name, partial_path,
prefix_path,
vbase_class_type.GetCanonicalType(), request);
}
}
// We are in a type parsing child members
const uint32_t num_fields = compiler_type.GetNumFields();
if (num_fields > 0) {
for (uint32_t i = 0; i < num_fields; ++i) {
std::string member_name;
CompilerType member_compiler_type = compiler_type.GetFieldAtIndex(
i, member_name, nullptr, nullptr, nullptr);
if (partial_member_name.empty()) {
request.AddCompletion((prefix_path + member_name).str());
} else if (llvm::StringRef(member_name)
.starts_with(partial_member_name)) {
if (member_name == partial_member_name) {
PrivateAutoComplete(
frame, partial_path,
prefix_path + member_name, // Anything that has been resolved
// already will be in here
member_compiler_type.GetCanonicalType(), request);
} else if (partial_path.empty()) {
request.AddCompletion((prefix_path + member_name).str());
}
}
}
}
}
static void PrivateAutoComplete(
StackFrame *frame, llvm::StringRef partial_path,
const llvm::Twine
&prefix_path, // Anything that has been resolved already will be in here
const CompilerType &compiler_type, CompletionRequest &request) {
// printf ("\nPrivateAutoComplete()\n\tprefix_path = '%s'\n\tpartial_path =
// '%s'\n", prefix_path.c_str(), partial_path.c_str());
std::string remaining_partial_path;
const lldb::TypeClass type_class = compiler_type.GetTypeClass();
if (partial_path.empty()) {
if (compiler_type.IsValid()) {
switch (type_class) {
default:
case eTypeClassArray:
case eTypeClassBlockPointer:
case eTypeClassBuiltin:
case eTypeClassComplexFloat:
case eTypeClassComplexInteger:
case eTypeClassEnumeration:
case eTypeClassFunction:
case eTypeClassMemberPointer:
case eTypeClassReference:
case eTypeClassTypedef:
case eTypeClassVector: {
request.AddCompletion(prefix_path.str());
} break;
case eTypeClassClass:
case eTypeClassStruct:
case eTypeClassUnion:
if (prefix_path.str().back() != '.')
request.AddCompletion((prefix_path + ".").str());
break;
case eTypeClassObjCObject:
case eTypeClassObjCInterface:
break;
case eTypeClassObjCObjectPointer:
case eTypeClassPointer: {
bool omit_empty_base_classes = true;
if (llvm::expectedToStdOptional(
compiler_type.GetNumChildren(omit_empty_base_classes, nullptr))
.value_or(0))
request.AddCompletion((prefix_path + "->").str());
else {
request.AddCompletion(prefix_path.str());
}
} break;
}
} else {
if (frame) {
const bool get_file_globals = true;
VariableList *variable_list = frame->GetVariableList(get_file_globals,
nullptr);
if (variable_list) {
for (const VariableSP &var_sp : *variable_list)
request.AddCompletion(var_sp->GetName().AsCString());
}
}
}
} else {
const char ch = partial_path[0];
switch (ch) {
case '*':
if (prefix_path.str().empty()) {
PrivateAutoComplete(frame, partial_path.substr(1), "*", compiler_type,
request);
}
break;
case '&':
if (prefix_path.isTriviallyEmpty()) {
PrivateAutoComplete(frame, partial_path.substr(1), std::string("&"),
compiler_type, request);
}
break;
case '-':
if (partial_path.size() > 1 && partial_path[1] == '>' &&
!prefix_path.str().empty()) {
switch (type_class) {
case lldb::eTypeClassPointer: {
CompilerType pointee_type(compiler_type.GetPointeeType());
if (partial_path.size() > 2 && partial_path[2]) {
// If there is more after the "->", then search deeper
PrivateAutoComplete(frame, partial_path.substr(2),
prefix_path + "->",
pointee_type.GetCanonicalType(), request);
} else {
// Nothing after the "->", so list all members
PrivateAutoCompleteMembers(
frame, std::string(), std::string(), prefix_path + "->",
pointee_type.GetCanonicalType(), request);
}
} break;
default:
break;
}
}
break;
case '.':
if (compiler_type.IsValid()) {
switch (type_class) {
case lldb::eTypeClassUnion:
case lldb::eTypeClassStruct:
case lldb::eTypeClassClass:
if (partial_path.size() > 1 && partial_path[1]) {
// If there is more after the ".", then search deeper
PrivateAutoComplete(frame, partial_path.substr(1),
prefix_path + ".", compiler_type, request);
} else {
// Nothing after the ".", so list all members
PrivateAutoCompleteMembers(frame, std::string(), partial_path,
prefix_path + ".", compiler_type,
request);
}
break;
default:
break;
}
}
break;
default:
if (isalpha(ch) || ch == '_' || ch == '$') {
const size_t partial_path_len = partial_path.size();
size_t pos = 1;
while (pos < partial_path_len) {
const char curr_ch = partial_path[pos];
if (isalnum(curr_ch) || curr_ch == '_' || curr_ch == '$') {
++pos;
continue;
}
break;
}
std::string token(std::string(partial_path), 0, pos);
remaining_partial_path = std::string(partial_path.substr(pos));
if (compiler_type.IsValid()) {
PrivateAutoCompleteMembers(frame, token, remaining_partial_path,
prefix_path, compiler_type, request);
} else if (frame) {
// We haven't found our variable yet
const bool get_file_globals = true;
VariableList *variable_list =
frame->GetVariableList(get_file_globals, nullptr);
if (!variable_list)
break;
for (VariableSP var_sp : *variable_list) {
if (!var_sp)
continue;
llvm::StringRef variable_name = var_sp->GetName().GetStringRef();
if (variable_name.starts_with(token)) {
if (variable_name == token) {
Type *variable_type = var_sp->GetType();
if (variable_type) {
CompilerType variable_compiler_type(
variable_type->GetForwardCompilerType());
PrivateAutoComplete(
frame, remaining_partial_path,
prefix_path + token, // Anything that has been resolved
// already will be in here
variable_compiler_type.GetCanonicalType(), request);
} else {
request.AddCompletion((prefix_path + variable_name).str());
}
} else if (remaining_partial_path.empty()) {
request.AddCompletion((prefix_path + variable_name).str());
}
}
}
}
}
break;
}
}
}
void Variable::AutoComplete(const ExecutionContext &exe_ctx,
CompletionRequest &request) {
CompilerType compiler_type;
PrivateAutoComplete(exe_ctx.GetFramePtr(), request.GetCursorArgumentPrefix(),
"", compiler_type, request);
}