Greg Clayton ec1a491701 Create synthetic symbol names on demand to improve memory consumption and startup times.
This is a resubmission of https://reviews.llvm.org/D105160 after fixing testing issues.

This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool.

Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index.

This patch fixes the issue by:

not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed
doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen
removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool
Prior to this fix the startup times for a large application was:
12.5 seconds (cold file caches)
8.5 seconds (warm file caches)

After this fix:
9.7 seconds (cold file caches)
5.7 seconds (warm file caches)

The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name.

Differential Revision: https://reviews.llvm.org/D106837
2021-07-27 16:51:12 -07:00

1150 lines
40 KiB
C++

//===-- Symtab.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 <map>
#include <set>
#include "lldb/Core/Module.h"
#include "lldb/Core/RichManglingContext.h"
#include "lldb/Core/Section.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/Symbol.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/Symtab.h"
#include "lldb/Target/Language.h"
#include "lldb/Utility/RegularExpression.h"
#include "lldb/Utility/Stream.h"
#include "lldb/Utility/Timer.h"
#include "llvm/ADT/StringRef.h"
using namespace lldb;
using namespace lldb_private;
Symtab::Symtab(ObjectFile *objfile)
: m_objfile(objfile), m_symbols(), m_file_addr_to_index(*this),
m_name_to_symbol_indices(), m_mutex(),
m_file_addr_to_index_computed(false), m_name_indexes_computed(false) {
m_name_to_symbol_indices.emplace(std::make_pair(
lldb::eFunctionNameTypeNone, UniqueCStringMap<uint32_t>()));
m_name_to_symbol_indices.emplace(std::make_pair(
lldb::eFunctionNameTypeBase, UniqueCStringMap<uint32_t>()));
m_name_to_symbol_indices.emplace(std::make_pair(
lldb::eFunctionNameTypeMethod, UniqueCStringMap<uint32_t>()));
m_name_to_symbol_indices.emplace(std::make_pair(
lldb::eFunctionNameTypeSelector, UniqueCStringMap<uint32_t>()));
}
Symtab::~Symtab() = default;
void Symtab::Reserve(size_t count) {
// Clients should grab the mutex from this symbol table and lock it manually
// when calling this function to avoid performance issues.
m_symbols.reserve(count);
}
Symbol *Symtab::Resize(size_t count) {
// Clients should grab the mutex from this symbol table and lock it manually
// when calling this function to avoid performance issues.
m_symbols.resize(count);
return m_symbols.empty() ? nullptr : &m_symbols[0];
}
uint32_t Symtab::AddSymbol(const Symbol &symbol) {
// Clients should grab the mutex from this symbol table and lock it manually
// when calling this function to avoid performance issues.
uint32_t symbol_idx = m_symbols.size();
auto &name_to_index = GetNameToSymbolIndexMap(lldb::eFunctionNameTypeNone);
name_to_index.Clear();
m_file_addr_to_index.Clear();
m_symbols.push_back(symbol);
m_file_addr_to_index_computed = false;
m_name_indexes_computed = false;
return symbol_idx;
}
size_t Symtab::GetNumSymbols() const {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
return m_symbols.size();
}
void Symtab::SectionFileAddressesChanged() {
auto &name_to_index = GetNameToSymbolIndexMap(lldb::eFunctionNameTypeNone);
name_to_index.Clear();
m_file_addr_to_index_computed = false;
}
void Symtab::Dump(Stream *s, Target *target, SortOrder sort_order,
Mangled::NamePreference name_preference) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
// s->Printf("%.*p: ", (int)sizeof(void*) * 2, this);
s->Indent();
const FileSpec &file_spec = m_objfile->GetFileSpec();
const char *object_name = nullptr;
if (m_objfile->GetModule())
object_name = m_objfile->GetModule()->GetObjectName().GetCString();
if (file_spec)
s->Printf("Symtab, file = %s%s%s%s, num_symbols = %" PRIu64,
file_spec.GetPath().c_str(), object_name ? "(" : "",
object_name ? object_name : "", object_name ? ")" : "",
(uint64_t)m_symbols.size());
else
s->Printf("Symtab, num_symbols = %" PRIu64 "", (uint64_t)m_symbols.size());
if (!m_symbols.empty()) {
switch (sort_order) {
case eSortOrderNone: {
s->PutCString(":\n");
DumpSymbolHeader(s);
const_iterator begin = m_symbols.begin();
const_iterator end = m_symbols.end();
for (const_iterator pos = m_symbols.begin(); pos != end; ++pos) {
s->Indent();
pos->Dump(s, target, std::distance(begin, pos), name_preference);
}
} break;
case eSortOrderByName: {
// Although we maintain a lookup by exact name map, the table isn't
// sorted by name. So we must make the ordered symbol list up ourselves.
s->PutCString(" (sorted by name):\n");
DumpSymbolHeader(s);
std::multimap<llvm::StringRef, const Symbol *> name_map;
for (const_iterator pos = m_symbols.begin(), end = m_symbols.end();
pos != end; ++pos) {
const char *name = pos->GetName().AsCString();
if (name && name[0])
name_map.insert(std::make_pair(name, &(*pos)));
}
for (const auto &name_to_symbol : name_map) {
const Symbol *symbol = name_to_symbol.second;
s->Indent();
symbol->Dump(s, target, symbol - &m_symbols[0], name_preference);
}
} break;
case eSortOrderByAddress:
s->PutCString(" (sorted by address):\n");
DumpSymbolHeader(s);
if (!m_file_addr_to_index_computed)
InitAddressIndexes();
const size_t num_entries = m_file_addr_to_index.GetSize();
for (size_t i = 0; i < num_entries; ++i) {
s->Indent();
const uint32_t symbol_idx = m_file_addr_to_index.GetEntryRef(i).data;
m_symbols[symbol_idx].Dump(s, target, symbol_idx, name_preference);
}
break;
}
} else {
s->PutCString("\n");
}
}
void Symtab::Dump(Stream *s, Target *target, std::vector<uint32_t> &indexes,
Mangled::NamePreference name_preference) const {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
const size_t num_symbols = GetNumSymbols();
// s->Printf("%.*p: ", (int)sizeof(void*) * 2, this);
s->Indent();
s->Printf("Symtab %" PRIu64 " symbol indexes (%" PRIu64 " symbols total):\n",
(uint64_t)indexes.size(), (uint64_t)m_symbols.size());
s->IndentMore();
if (!indexes.empty()) {
std::vector<uint32_t>::const_iterator pos;
std::vector<uint32_t>::const_iterator end = indexes.end();
DumpSymbolHeader(s);
for (pos = indexes.begin(); pos != end; ++pos) {
size_t idx = *pos;
if (idx < num_symbols) {
s->Indent();
m_symbols[idx].Dump(s, target, idx, name_preference);
}
}
}
s->IndentLess();
}
void Symtab::DumpSymbolHeader(Stream *s) {
s->Indent(" Debug symbol\n");
s->Indent(" |Synthetic symbol\n");
s->Indent(" ||Externally Visible\n");
s->Indent(" |||\n");
s->Indent("Index UserID DSX Type File Address/Value Load "
"Address Size Flags Name\n");
s->Indent("------- ------ --- --------------- ------------------ "
"------------------ ------------------ ---------- "
"----------------------------------\n");
}
static int CompareSymbolID(const void *key, const void *p) {
const user_id_t match_uid = *(const user_id_t *)key;
const user_id_t symbol_uid = ((const Symbol *)p)->GetID();
if (match_uid < symbol_uid)
return -1;
if (match_uid > symbol_uid)
return 1;
return 0;
}
Symbol *Symtab::FindSymbolByID(lldb::user_id_t symbol_uid) const {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
Symbol *symbol =
(Symbol *)::bsearch(&symbol_uid, &m_symbols[0], m_symbols.size(),
sizeof(m_symbols[0]), CompareSymbolID);
return symbol;
}
Symbol *Symtab::SymbolAtIndex(size_t idx) {
// Clients should grab the mutex from this symbol table and lock it manually
// when calling this function to avoid performance issues.
if (idx < m_symbols.size())
return &m_symbols[idx];
return nullptr;
}
const Symbol *Symtab::SymbolAtIndex(size_t idx) const {
// Clients should grab the mutex from this symbol table and lock it manually
// when calling this function to avoid performance issues.
if (idx < m_symbols.size())
return &m_symbols[idx];
return nullptr;
}
static bool lldb_skip_name(llvm::StringRef mangled,
Mangled::ManglingScheme scheme) {
switch (scheme) {
case Mangled::eManglingSchemeItanium: {
if (mangled.size() < 3 || !mangled.startswith("_Z"))
return true;
// Avoid the following types of symbols in the index.
switch (mangled[2]) {
case 'G': // guard variables
case 'T': // virtual tables, VTT structures, typeinfo structures + names
case 'Z': // named local entities (if we eventually handle
// eSymbolTypeData, we will want this back)
return true;
default:
break;
}
// Include this name in the index.
return false;
}
// No filters for this scheme yet. Include all names in indexing.
case Mangled::eManglingSchemeMSVC:
return false;
// No filters for this scheme yet. Include all names in indexing.
case Mangled::eManglingSchemeRustV0:
return false;
// Don't try and demangle things we can't categorize.
case Mangled::eManglingSchemeNone:
return true;
}
llvm_unreachable("unknown scheme!");
}
void Symtab::InitNameIndexes() {
// Protected function, no need to lock mutex...
if (!m_name_indexes_computed) {
m_name_indexes_computed = true;
LLDB_SCOPED_TIMER();
// Collect all loaded language plugins.
std::vector<Language *> languages;
Language::ForEach([&languages](Language *l) {
languages.push_back(l);
return true;
});
auto &name_to_index = GetNameToSymbolIndexMap(lldb::eFunctionNameTypeNone);
auto &basename_to_index =
GetNameToSymbolIndexMap(lldb::eFunctionNameTypeBase);
auto &method_to_index =
GetNameToSymbolIndexMap(lldb::eFunctionNameTypeMethod);
auto &selector_to_index =
GetNameToSymbolIndexMap(lldb::eFunctionNameTypeSelector);
// Create the name index vector to be able to quickly search by name
const size_t num_symbols = m_symbols.size();
name_to_index.Reserve(num_symbols);
// The "const char *" in "class_contexts" and backlog::value_type::second
// must come from a ConstString::GetCString()
std::set<const char *> class_contexts;
std::vector<std::pair<NameToIndexMap::Entry, const char *>> backlog;
backlog.reserve(num_symbols / 2);
// Instantiation of the demangler is expensive, so better use a single one
// for all entries during batch processing.
RichManglingContext rmc;
for (uint32_t value = 0; value < num_symbols; ++value) {
Symbol *symbol = &m_symbols[value];
// Don't let trampolines get into the lookup by name map If we ever need
// the trampoline symbols to be searchable by name we can remove this and
// then possibly add a new bool to any of the Symtab functions that
// lookup symbols by name to indicate if they want trampolines. We also
// don't want any synthetic symbols with auto generated names in the
// name lookups.
if (symbol->IsTrampoline() || symbol->IsSyntheticWithAutoGeneratedName())
continue;
// If the symbol's name string matched a Mangled::ManglingScheme, it is
// stored in the mangled field.
Mangled &mangled = symbol->GetMangled();
if (ConstString name = mangled.GetMangledName()) {
name_to_index.Append(name, value);
if (symbol->ContainsLinkerAnnotations()) {
// If the symbol has linker annotations, also add the version without
// the annotations.
ConstString stripped = ConstString(
m_objfile->StripLinkerSymbolAnnotations(name.GetStringRef()));
name_to_index.Append(stripped, value);
}
const SymbolType type = symbol->GetType();
if (type == eSymbolTypeCode || type == eSymbolTypeResolver) {
if (mangled.DemangleWithRichManglingInfo(rmc, lldb_skip_name))
RegisterMangledNameEntry(value, class_contexts, backlog, rmc);
}
}
// Symbol name strings that didn't match a Mangled::ManglingScheme, are
// stored in the demangled field.
if (ConstString name = mangled.GetDemangledName()) {
name_to_index.Append(name, value);
if (symbol->ContainsLinkerAnnotations()) {
// If the symbol has linker annotations, also add the version without
// the annotations.
name = ConstString(
m_objfile->StripLinkerSymbolAnnotations(name.GetStringRef()));
name_to_index.Append(name, value);
}
// If the demangled name turns out to be an ObjC name, and is a category
// name, add the version without categories to the index too.
for (Language *lang : languages) {
for (auto variant : lang->GetMethodNameVariants(name)) {
if (variant.GetType() & lldb::eFunctionNameTypeSelector)
selector_to_index.Append(variant.GetName(), value);
else if (variant.GetType() & lldb::eFunctionNameTypeFull)
name_to_index.Append(variant.GetName(), value);
else if (variant.GetType() & lldb::eFunctionNameTypeMethod)
method_to_index.Append(variant.GetName(), value);
else if (variant.GetType() & lldb::eFunctionNameTypeBase)
basename_to_index.Append(variant.GetName(), value);
}
}
}
}
for (const auto &record : backlog) {
RegisterBacklogEntry(record.first, record.second, class_contexts);
}
name_to_index.Sort();
name_to_index.SizeToFit();
selector_to_index.Sort();
selector_to_index.SizeToFit();
basename_to_index.Sort();
basename_to_index.SizeToFit();
method_to_index.Sort();
method_to_index.SizeToFit();
}
}
void Symtab::RegisterMangledNameEntry(
uint32_t value, std::set<const char *> &class_contexts,
std::vector<std::pair<NameToIndexMap::Entry, const char *>> &backlog,
RichManglingContext &rmc) {
// Only register functions that have a base name.
rmc.ParseFunctionBaseName();
llvm::StringRef base_name = rmc.GetBufferRef();
if (base_name.empty())
return;
// The base name will be our entry's name.
NameToIndexMap::Entry entry(ConstString(base_name), value);
rmc.ParseFunctionDeclContextName();
llvm::StringRef decl_context = rmc.GetBufferRef();
// Register functions with no context.
if (decl_context.empty()) {
// This has to be a basename
auto &basename_to_index =
GetNameToSymbolIndexMap(lldb::eFunctionNameTypeBase);
basename_to_index.Append(entry);
// If there is no context (no namespaces or class scopes that come before
// the function name) then this also could be a fullname.
auto &name_to_index = GetNameToSymbolIndexMap(lldb::eFunctionNameTypeNone);
name_to_index.Append(entry);
return;
}
// Make sure we have a pool-string pointer and see if we already know the
// context name.
const char *decl_context_ccstr = ConstString(decl_context).GetCString();
auto it = class_contexts.find(decl_context_ccstr);
auto &method_to_index =
GetNameToSymbolIndexMap(lldb::eFunctionNameTypeMethod);
// Register constructors and destructors. They are methods and create
// declaration contexts.
if (rmc.IsCtorOrDtor()) {
method_to_index.Append(entry);
if (it == class_contexts.end())
class_contexts.insert(it, decl_context_ccstr);
return;
}
// Register regular methods with a known declaration context.
if (it != class_contexts.end()) {
method_to_index.Append(entry);
return;
}
// Regular methods in unknown declaration contexts are put to the backlog. We
// will revisit them once we processed all remaining symbols.
backlog.push_back(std::make_pair(entry, decl_context_ccstr));
}
void Symtab::RegisterBacklogEntry(
const NameToIndexMap::Entry &entry, const char *decl_context,
const std::set<const char *> &class_contexts) {
auto &method_to_index =
GetNameToSymbolIndexMap(lldb::eFunctionNameTypeMethod);
auto it = class_contexts.find(decl_context);
if (it != class_contexts.end()) {
method_to_index.Append(entry);
} else {
// If we got here, we have something that had a context (was inside
// a namespace or class) yet we don't know the entry
method_to_index.Append(entry);
auto &basename_to_index =
GetNameToSymbolIndexMap(lldb::eFunctionNameTypeBase);
basename_to_index.Append(entry);
}
}
void Symtab::PreloadSymbols() {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
InitNameIndexes();
}
void Symtab::AppendSymbolNamesToMap(const IndexCollection &indexes,
bool add_demangled, bool add_mangled,
NameToIndexMap &name_to_index_map) const {
LLDB_SCOPED_TIMER();
if (add_demangled || add_mangled) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
// Create the name index vector to be able to quickly search by name
const size_t num_indexes = indexes.size();
for (size_t i = 0; i < num_indexes; ++i) {
uint32_t value = indexes[i];
assert(i < m_symbols.size());
const Symbol *symbol = &m_symbols[value];
const Mangled &mangled = symbol->GetMangled();
if (add_demangled) {
if (ConstString name = mangled.GetDemangledName())
name_to_index_map.Append(name, value);
}
if (add_mangled) {
if (ConstString name = mangled.GetMangledName())
name_to_index_map.Append(name, value);
}
}
}
}
uint32_t Symtab::AppendSymbolIndexesWithType(SymbolType symbol_type,
std::vector<uint32_t> &indexes,
uint32_t start_idx,
uint32_t end_index) const {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
uint32_t prev_size = indexes.size();
const uint32_t count = std::min<uint32_t>(m_symbols.size(), end_index);
for (uint32_t i = start_idx; i < count; ++i) {
if (symbol_type == eSymbolTypeAny || m_symbols[i].GetType() == symbol_type)
indexes.push_back(i);
}
return indexes.size() - prev_size;
}
uint32_t Symtab::AppendSymbolIndexesWithTypeAndFlagsValue(
SymbolType symbol_type, uint32_t flags_value,
std::vector<uint32_t> &indexes, uint32_t start_idx,
uint32_t end_index) const {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
uint32_t prev_size = indexes.size();
const uint32_t count = std::min<uint32_t>(m_symbols.size(), end_index);
for (uint32_t i = start_idx; i < count; ++i) {
if ((symbol_type == eSymbolTypeAny ||
m_symbols[i].GetType() == symbol_type) &&
m_symbols[i].GetFlags() == flags_value)
indexes.push_back(i);
}
return indexes.size() - prev_size;
}
uint32_t Symtab::AppendSymbolIndexesWithType(SymbolType symbol_type,
Debug symbol_debug_type,
Visibility symbol_visibility,
std::vector<uint32_t> &indexes,
uint32_t start_idx,
uint32_t end_index) const {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
uint32_t prev_size = indexes.size();
const uint32_t count = std::min<uint32_t>(m_symbols.size(), end_index);
for (uint32_t i = start_idx; i < count; ++i) {
if (symbol_type == eSymbolTypeAny ||
m_symbols[i].GetType() == symbol_type) {
if (CheckSymbolAtIndex(i, symbol_debug_type, symbol_visibility))
indexes.push_back(i);
}
}
return indexes.size() - prev_size;
}
uint32_t Symtab::GetIndexForSymbol(const Symbol *symbol) const {
if (!m_symbols.empty()) {
const Symbol *first_symbol = &m_symbols[0];
if (symbol >= first_symbol && symbol < first_symbol + m_symbols.size())
return symbol - first_symbol;
}
return UINT32_MAX;
}
struct SymbolSortInfo {
const bool sort_by_load_addr;
const Symbol *symbols;
};
namespace {
struct SymbolIndexComparator {
const std::vector<Symbol> &symbols;
std::vector<lldb::addr_t> &addr_cache;
// Getting from the symbol to the Address to the File Address involves some
// work. Since there are potentially many symbols here, and we're using this
// for sorting so we're going to be computing the address many times, cache
// that in addr_cache. The array passed in has to be the same size as the
// symbols array passed into the member variable symbols, and should be
// initialized with LLDB_INVALID_ADDRESS.
// NOTE: You have to make addr_cache externally and pass it in because
// std::stable_sort
// makes copies of the comparator it is initially passed in, and you end up
// spending huge amounts of time copying this array...
SymbolIndexComparator(const std::vector<Symbol> &s,
std::vector<lldb::addr_t> &a)
: symbols(s), addr_cache(a) {
assert(symbols.size() == addr_cache.size());
}
bool operator()(uint32_t index_a, uint32_t index_b) {
addr_t value_a = addr_cache[index_a];
if (value_a == LLDB_INVALID_ADDRESS) {
value_a = symbols[index_a].GetAddressRef().GetFileAddress();
addr_cache[index_a] = value_a;
}
addr_t value_b = addr_cache[index_b];
if (value_b == LLDB_INVALID_ADDRESS) {
value_b = symbols[index_b].GetAddressRef().GetFileAddress();
addr_cache[index_b] = value_b;
}
if (value_a == value_b) {
// The if the values are equal, use the original symbol user ID
lldb::user_id_t uid_a = symbols[index_a].GetID();
lldb::user_id_t uid_b = symbols[index_b].GetID();
if (uid_a < uid_b)
return true;
if (uid_a > uid_b)
return false;
return false;
} else if (value_a < value_b)
return true;
return false;
}
};
}
void Symtab::SortSymbolIndexesByValue(std::vector<uint32_t> &indexes,
bool remove_duplicates) const {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
LLDB_SCOPED_TIMER();
// No need to sort if we have zero or one items...
if (indexes.size() <= 1)
return;
// Sort the indexes in place using std::stable_sort.
// NOTE: The use of std::stable_sort instead of llvm::sort here is strictly
// for performance, not correctness. The indexes vector tends to be "close"
// to sorted, which the stable sort handles better.
std::vector<lldb::addr_t> addr_cache(m_symbols.size(), LLDB_INVALID_ADDRESS);
SymbolIndexComparator comparator(m_symbols, addr_cache);
std::stable_sort(indexes.begin(), indexes.end(), comparator);
// Remove any duplicates if requested
if (remove_duplicates) {
auto last = std::unique(indexes.begin(), indexes.end());
indexes.erase(last, indexes.end());
}
}
uint32_t Symtab::GetNameIndexes(ConstString symbol_name,
std::vector<uint32_t> &indexes) {
auto &name_to_index = GetNameToSymbolIndexMap(lldb::eFunctionNameTypeNone);
const uint32_t count = name_to_index.GetValues(symbol_name, indexes);
if (count)
return count;
// Synthetic symbol names are not added to the name indexes, but they start
// with a prefix and end with a the symbol UserID. This allows users to find
// these symbols without having to add them to the name indexes. These
// queries will not happen very often since the names don't mean anything, so
// performance is not paramount in this case.
llvm::StringRef name = symbol_name.GetStringRef();
// String the synthetic prefix if the name starts with it.
if (!name.consume_front(Symbol::GetSyntheticSymbolPrefix()))
return 0; // Not a synthetic symbol name
// Extract the user ID from the symbol name
unsigned long long uid = 0;
if (getAsUnsignedInteger(name, /*Radix=*/10, uid))
return 0; // Failed to extract the user ID as an integer
Symbol *symbol = FindSymbolByID(uid);
if (symbol == nullptr)
return 0;
const uint32_t symbol_idx = GetIndexForSymbol(symbol);
if (symbol_idx == UINT32_MAX)
return 0;
indexes.push_back(symbol_idx);
return 1;
}
uint32_t Symtab::AppendSymbolIndexesWithName(ConstString symbol_name,
std::vector<uint32_t> &indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
LLDB_SCOPED_TIMER();
if (symbol_name) {
if (!m_name_indexes_computed)
InitNameIndexes();
return GetNameIndexes(symbol_name, indexes);
}
return 0;
}
uint32_t Symtab::AppendSymbolIndexesWithName(ConstString symbol_name,
Debug symbol_debug_type,
Visibility symbol_visibility,
std::vector<uint32_t> &indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
LLDB_SCOPED_TIMER();
if (symbol_name) {
const size_t old_size = indexes.size();
if (!m_name_indexes_computed)
InitNameIndexes();
std::vector<uint32_t> all_name_indexes;
const size_t name_match_count =
GetNameIndexes(symbol_name, all_name_indexes);
for (size_t i = 0; i < name_match_count; ++i) {
if (CheckSymbolAtIndex(all_name_indexes[i], symbol_debug_type,
symbol_visibility))
indexes.push_back(all_name_indexes[i]);
}
return indexes.size() - old_size;
}
return 0;
}
uint32_t
Symtab::AppendSymbolIndexesWithNameAndType(ConstString symbol_name,
SymbolType symbol_type,
std::vector<uint32_t> &indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (AppendSymbolIndexesWithName(symbol_name, indexes) > 0) {
std::vector<uint32_t>::iterator pos = indexes.begin();
while (pos != indexes.end()) {
if (symbol_type == eSymbolTypeAny ||
m_symbols[*pos].GetType() == symbol_type)
++pos;
else
pos = indexes.erase(pos);
}
}
return indexes.size();
}
uint32_t Symtab::AppendSymbolIndexesWithNameAndType(
ConstString symbol_name, SymbolType symbol_type,
Debug symbol_debug_type, Visibility symbol_visibility,
std::vector<uint32_t> &indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (AppendSymbolIndexesWithName(symbol_name, symbol_debug_type,
symbol_visibility, indexes) > 0) {
std::vector<uint32_t>::iterator pos = indexes.begin();
while (pos != indexes.end()) {
if (symbol_type == eSymbolTypeAny ||
m_symbols[*pos].GetType() == symbol_type)
++pos;
else
pos = indexes.erase(pos);
}
}
return indexes.size();
}
uint32_t Symtab::AppendSymbolIndexesMatchingRegExAndType(
const RegularExpression &regexp, SymbolType symbol_type,
std::vector<uint32_t> &indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
uint32_t prev_size = indexes.size();
uint32_t sym_end = m_symbols.size();
for (uint32_t i = 0; i < sym_end; i++) {
if (symbol_type == eSymbolTypeAny ||
m_symbols[i].GetType() == symbol_type) {
const char *name = m_symbols[i].GetName().AsCString();
if (name) {
if (regexp.Execute(name))
indexes.push_back(i);
}
}
}
return indexes.size() - prev_size;
}
uint32_t Symtab::AppendSymbolIndexesMatchingRegExAndType(
const RegularExpression &regexp, SymbolType symbol_type,
Debug symbol_debug_type, Visibility symbol_visibility,
std::vector<uint32_t> &indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
uint32_t prev_size = indexes.size();
uint32_t sym_end = m_symbols.size();
for (uint32_t i = 0; i < sym_end; i++) {
if (symbol_type == eSymbolTypeAny ||
m_symbols[i].GetType() == symbol_type) {
if (!CheckSymbolAtIndex(i, symbol_debug_type, symbol_visibility))
continue;
const char *name = m_symbols[i].GetName().AsCString();
if (name) {
if (regexp.Execute(name))
indexes.push_back(i);
}
}
}
return indexes.size() - prev_size;
}
Symbol *Symtab::FindSymbolWithType(SymbolType symbol_type,
Debug symbol_debug_type,
Visibility symbol_visibility,
uint32_t &start_idx) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
const size_t count = m_symbols.size();
for (size_t idx = start_idx; idx < count; ++idx) {
if (symbol_type == eSymbolTypeAny ||
m_symbols[idx].GetType() == symbol_type) {
if (CheckSymbolAtIndex(idx, symbol_debug_type, symbol_visibility)) {
start_idx = idx;
return &m_symbols[idx];
}
}
}
return nullptr;
}
void
Symtab::FindAllSymbolsWithNameAndType(ConstString name,
SymbolType symbol_type,
std::vector<uint32_t> &symbol_indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
LLDB_SCOPED_TIMER();
// Initialize all of the lookup by name indexes before converting NAME to a
// uniqued string NAME_STR below.
if (!m_name_indexes_computed)
InitNameIndexes();
if (name) {
// The string table did have a string that matched, but we need to check
// the symbols and match the symbol_type if any was given.
AppendSymbolIndexesWithNameAndType(name, symbol_type, symbol_indexes);
}
}
void Symtab::FindAllSymbolsWithNameAndType(
ConstString name, SymbolType symbol_type, Debug symbol_debug_type,
Visibility symbol_visibility, std::vector<uint32_t> &symbol_indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
LLDB_SCOPED_TIMER();
// Initialize all of the lookup by name indexes before converting NAME to a
// uniqued string NAME_STR below.
if (!m_name_indexes_computed)
InitNameIndexes();
if (name) {
// The string table did have a string that matched, but we need to check
// the symbols and match the symbol_type if any was given.
AppendSymbolIndexesWithNameAndType(name, symbol_type, symbol_debug_type,
symbol_visibility, symbol_indexes);
}
}
void Symtab::FindAllSymbolsMatchingRexExAndType(
const RegularExpression &regex, SymbolType symbol_type,
Debug symbol_debug_type, Visibility symbol_visibility,
std::vector<uint32_t> &symbol_indexes) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
AppendSymbolIndexesMatchingRegExAndType(regex, symbol_type, symbol_debug_type,
symbol_visibility, symbol_indexes);
}
Symbol *Symtab::FindFirstSymbolWithNameAndType(ConstString name,
SymbolType symbol_type,
Debug symbol_debug_type,
Visibility symbol_visibility) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
LLDB_SCOPED_TIMER();
if (!m_name_indexes_computed)
InitNameIndexes();
if (name) {
std::vector<uint32_t> matching_indexes;
// The string table did have a string that matched, but we need to check
// the symbols and match the symbol_type if any was given.
if (AppendSymbolIndexesWithNameAndType(name, symbol_type, symbol_debug_type,
symbol_visibility,
matching_indexes)) {
std::vector<uint32_t>::const_iterator pos, end = matching_indexes.end();
for (pos = matching_indexes.begin(); pos != end; ++pos) {
Symbol *symbol = SymbolAtIndex(*pos);
if (symbol->Compare(name, symbol_type))
return symbol;
}
}
}
return nullptr;
}
typedef struct {
const Symtab *symtab;
const addr_t file_addr;
Symbol *match_symbol;
const uint32_t *match_index_ptr;
addr_t match_offset;
} SymbolSearchInfo;
// Add all the section file start address & size to the RangeVector, recusively
// adding any children sections.
static void AddSectionsToRangeMap(SectionList *sectlist,
RangeVector<addr_t, addr_t> &section_ranges) {
const int num_sections = sectlist->GetNumSections(0);
for (int i = 0; i < num_sections; i++) {
SectionSP sect_sp = sectlist->GetSectionAtIndex(i);
if (sect_sp) {
SectionList &child_sectlist = sect_sp->GetChildren();
// If this section has children, add the children to the RangeVector.
// Else add this section to the RangeVector.
if (child_sectlist.GetNumSections(0) > 0) {
AddSectionsToRangeMap(&child_sectlist, section_ranges);
} else {
size_t size = sect_sp->GetByteSize();
if (size > 0) {
addr_t base_addr = sect_sp->GetFileAddress();
RangeVector<addr_t, addr_t>::Entry entry;
entry.SetRangeBase(base_addr);
entry.SetByteSize(size);
section_ranges.Append(entry);
}
}
}
}
}
void Symtab::InitAddressIndexes() {
// Protected function, no need to lock mutex...
if (!m_file_addr_to_index_computed && !m_symbols.empty()) {
m_file_addr_to_index_computed = true;
FileRangeToIndexMap::Entry entry;
const_iterator begin = m_symbols.begin();
const_iterator end = m_symbols.end();
for (const_iterator pos = m_symbols.begin(); pos != end; ++pos) {
if (pos->ValueIsAddress()) {
entry.SetRangeBase(pos->GetAddressRef().GetFileAddress());
entry.SetByteSize(pos->GetByteSize());
entry.data = std::distance(begin, pos);
m_file_addr_to_index.Append(entry);
}
}
const size_t num_entries = m_file_addr_to_index.GetSize();
if (num_entries > 0) {
m_file_addr_to_index.Sort();
// Create a RangeVector with the start & size of all the sections for
// this objfile. We'll need to check this for any FileRangeToIndexMap
// entries with an uninitialized size, which could potentially be a large
// number so reconstituting the weak pointer is busywork when it is
// invariant information.
SectionList *sectlist = m_objfile->GetSectionList();
RangeVector<addr_t, addr_t> section_ranges;
if (sectlist) {
AddSectionsToRangeMap(sectlist, section_ranges);
section_ranges.Sort();
}
// Iterate through the FileRangeToIndexMap and fill in the size for any
// entries that didn't already have a size from the Symbol (e.g. if we
// have a plain linker symbol with an address only, instead of debug info
// where we get an address and a size and a type, etc.)
for (size_t i = 0; i < num_entries; i++) {
FileRangeToIndexMap::Entry *entry =
m_file_addr_to_index.GetMutableEntryAtIndex(i);
if (entry->GetByteSize() == 0) {
addr_t curr_base_addr = entry->GetRangeBase();
const RangeVector<addr_t, addr_t>::Entry *containing_section =
section_ranges.FindEntryThatContains(curr_base_addr);
// Use the end of the section as the default max size of the symbol
addr_t sym_size = 0;
if (containing_section) {
sym_size =
containing_section->GetByteSize() -
(entry->GetRangeBase() - containing_section->GetRangeBase());
}
for (size_t j = i; j < num_entries; j++) {
FileRangeToIndexMap::Entry *next_entry =
m_file_addr_to_index.GetMutableEntryAtIndex(j);
addr_t next_base_addr = next_entry->GetRangeBase();
if (next_base_addr > curr_base_addr) {
addr_t size_to_next_symbol = next_base_addr - curr_base_addr;
// Take the difference between this symbol and the next one as
// its size, if it is less than the size of the section.
if (sym_size == 0 || size_to_next_symbol < sym_size) {
sym_size = size_to_next_symbol;
}
break;
}
}
if (sym_size > 0) {
entry->SetByteSize(sym_size);
Symbol &symbol = m_symbols[entry->data];
symbol.SetByteSize(sym_size);
symbol.SetSizeIsSynthesized(true);
}
}
}
// Sort again in case the range size changes the ordering
m_file_addr_to_index.Sort();
}
}
}
void Symtab::CalculateSymbolSizes() {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
// Size computation happens inside InitAddressIndexes.
InitAddressIndexes();
}
Symbol *Symtab::FindSymbolAtFileAddress(addr_t file_addr) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (!m_file_addr_to_index_computed)
InitAddressIndexes();
const FileRangeToIndexMap::Entry *entry =
m_file_addr_to_index.FindEntryStartsAt(file_addr);
if (entry) {
Symbol *symbol = SymbolAtIndex(entry->data);
if (symbol->GetFileAddress() == file_addr)
return symbol;
}
return nullptr;
}
Symbol *Symtab::FindSymbolContainingFileAddress(addr_t file_addr) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (!m_file_addr_to_index_computed)
InitAddressIndexes();
const FileRangeToIndexMap::Entry *entry =
m_file_addr_to_index.FindEntryThatContains(file_addr);
if (entry) {
Symbol *symbol = SymbolAtIndex(entry->data);
if (symbol->ContainsFileAddress(file_addr))
return symbol;
}
return nullptr;
}
void Symtab::ForEachSymbolContainingFileAddress(
addr_t file_addr, std::function<bool(Symbol *)> const &callback) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (!m_file_addr_to_index_computed)
InitAddressIndexes();
std::vector<uint32_t> all_addr_indexes;
// Get all symbols with file_addr
const size_t addr_match_count =
m_file_addr_to_index.FindEntryIndexesThatContain(file_addr,
all_addr_indexes);
for (size_t i = 0; i < addr_match_count; ++i) {
Symbol *symbol = SymbolAtIndex(all_addr_indexes[i]);
if (symbol->ContainsFileAddress(file_addr)) {
if (!callback(symbol))
break;
}
}
}
void Symtab::SymbolIndicesToSymbolContextList(
std::vector<uint32_t> &symbol_indexes, SymbolContextList &sc_list) {
// No need to protect this call using m_mutex all other method calls are
// already thread safe.
const bool merge_symbol_into_function = true;
size_t num_indices = symbol_indexes.size();
if (num_indices > 0) {
SymbolContext sc;
sc.module_sp = m_objfile->GetModule();
for (size_t i = 0; i < num_indices; i++) {
sc.symbol = SymbolAtIndex(symbol_indexes[i]);
if (sc.symbol)
sc_list.AppendIfUnique(sc, merge_symbol_into_function);
}
}
}
void Symtab::FindFunctionSymbols(ConstString name, uint32_t name_type_mask,
SymbolContextList &sc_list) {
std::vector<uint32_t> symbol_indexes;
// eFunctionNameTypeAuto should be pre-resolved by a call to
// Module::LookupInfo::LookupInfo()
assert((name_type_mask & eFunctionNameTypeAuto) == 0);
if (name_type_mask & (eFunctionNameTypeBase | eFunctionNameTypeFull)) {
std::vector<uint32_t> temp_symbol_indexes;
FindAllSymbolsWithNameAndType(name, eSymbolTypeAny, temp_symbol_indexes);
unsigned temp_symbol_indexes_size = temp_symbol_indexes.size();
if (temp_symbol_indexes_size > 0) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
for (unsigned i = 0; i < temp_symbol_indexes_size; i++) {
SymbolContext sym_ctx;
sym_ctx.symbol = SymbolAtIndex(temp_symbol_indexes[i]);
if (sym_ctx.symbol) {
switch (sym_ctx.symbol->GetType()) {
case eSymbolTypeCode:
case eSymbolTypeResolver:
case eSymbolTypeReExported:
symbol_indexes.push_back(temp_symbol_indexes[i]);
break;
default:
break;
}
}
}
}
}
if (!m_name_indexes_computed)
InitNameIndexes();
for (lldb::FunctionNameType type :
{lldb::eFunctionNameTypeBase, lldb::eFunctionNameTypeMethod,
lldb::eFunctionNameTypeSelector}) {
if (name_type_mask & type) {
auto map = GetNameToSymbolIndexMap(type);
const UniqueCStringMap<uint32_t>::Entry *match;
for (match = map.FindFirstValueForName(name); match != nullptr;
match = map.FindNextValueForName(match)) {
symbol_indexes.push_back(match->value);
}
}
}
if (!symbol_indexes.empty()) {
llvm::sort(symbol_indexes.begin(), symbol_indexes.end());
symbol_indexes.erase(
std::unique(symbol_indexes.begin(), symbol_indexes.end()),
symbol_indexes.end());
SymbolIndicesToSymbolContextList(symbol_indexes, sc_list);
}
}
const Symbol *Symtab::GetParent(Symbol *child_symbol) const {
uint32_t child_idx = GetIndexForSymbol(child_symbol);
if (child_idx != UINT32_MAX && child_idx > 0) {
for (uint32_t idx = child_idx - 1; idx != UINT32_MAX; --idx) {
const Symbol *symbol = SymbolAtIndex(idx);
const uint32_t sibling_idx = symbol->GetSiblingIndex();
if (sibling_idx != UINT32_MAX && sibling_idx > child_idx)
return symbol;
}
}
return nullptr;
}