blob: 3e76b416d1a0d4121636977acac399100e88473d [file] [log] [blame]
//===- SymbolTable.h --------------------------------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "InputFiles.h"
#include "LTO.h"
#include "llvm/ADT/CachedHashString.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
struct LTOCodeGenerator;
namespace lld {
namespace coff {
class Chunk;
class CommonChunk;
class COFFLinkerContext;
class Defined;
class DefinedAbsolute;
class DefinedRegular;
class DefinedRelative;
class LazyArchive;
class SectionChunk;
class Symbol;
// SymbolTable is a bucket of all known symbols, including defined,
// undefined, or lazy symbols (the last one is symbols in archive
// files whose archive members are not yet loaded).
// We put all symbols of all files to a SymbolTable, and the
// SymbolTable selects the "best" symbols if there are name
// conflicts. For example, obviously, a defined symbol is better than
// an undefined symbol. Or, if there's a conflict between a lazy and a
// undefined, it'll read an archive member to read a real definition
// to replace the lazy symbol. The logic is implemented in the
// add*() functions, which are called by input files as they are parsed.
// There is one add* function per symbol type.
class SymbolTable {
SymbolTable(COFFLinkerContext &ctx) : ctx(ctx) {}
void addFile(InputFile *file);
// Emit errors for symbols that cannot be resolved.
void reportUnresolvable();
// Try to resolve any undefined symbols and update the symbol table
// accordingly, then print an error message for any remaining undefined
// symbols and warn about imported local symbols.
void resolveRemainingUndefines();
// Load lazy objects that are needed for MinGW automatic import and for
// doing stdcall fixups.
void loadMinGWSymbols();
bool handleMinGWAutomaticImport(Symbol *sym, StringRef name);
// Returns a list of chunks of selected symbols.
std::vector<Chunk *> getChunks() const;
// Returns a symbol for a given name. Returns a nullptr if not found.
Symbol *find(StringRef name) const;
Symbol *findUnderscore(StringRef name) const;
// Occasionally we have to resolve an undefined symbol to its
// mangled symbol. This function tries to find a mangled name
// for U from the symbol table, and if found, set the symbol as
// a weak alias for U.
Symbol *findMangle(StringRef name);
// Build a set of COFF objects representing the combined contents of
// BitcodeFiles and add them to the symbol table. Called after all files are
// added and before the writer writes results to a file.
void compileBitcodeFiles();
// Creates an Undefined symbol for a given name.
Symbol *addUndefined(StringRef name);
Symbol *addSynthetic(StringRef n, Chunk *c);
Symbol *addAbsolute(StringRef n, uint64_t va);
Symbol *addUndefined(StringRef name, InputFile *f, bool isWeakAlias);
void addLazyArchive(ArchiveFile *f, const Archive::Symbol &sym);
void addLazyObject(LazyObjFile *f, StringRef n);
void addLazyDLLSymbol(DLLFile *f, DLLFile::Symbol *sym, StringRef n);
Symbol *addAbsolute(StringRef n, COFFSymbolRef s);
Symbol *addRegular(InputFile *f, StringRef n,
const llvm::object::coff_symbol_generic *s = nullptr,
SectionChunk *c = nullptr, uint32_t sectionOffset = 0);
std::pair<DefinedRegular *, bool>
addComdat(InputFile *f, StringRef n,
const llvm::object::coff_symbol_generic *s = nullptr);
Symbol *addCommon(InputFile *f, StringRef n, uint64_t size,
const llvm::object::coff_symbol_generic *s = nullptr,
CommonChunk *c = nullptr);
Symbol *addImportData(StringRef n, ImportFile *f);
Symbol *addImportThunk(StringRef name, DefinedImportData *s,
uint16_t machine);
void addLibcall(StringRef name);
void reportDuplicate(Symbol *existing, InputFile *newFile,
SectionChunk *newSc = nullptr,
uint32_t newSectionOffset = 0);
// A list of chunks which to be added to .rdata.
std::vector<Chunk *> localImportChunks;
// Iterates symbols in non-determinstic hash table order.
template <typename T> void forEachSymbol(T callback) {
for (auto &pair : symMap)
/// Given a name without "__imp_" prefix, returns a defined symbol
/// with the "__imp_" prefix, if it exists.
Defined *impSymbol(StringRef name);
/// Inserts symbol if not already present.
std::pair<Symbol *, bool> insert(StringRef name);
/// Same as insert(Name), but also sets isUsedInRegularObj.
std::pair<Symbol *, bool> insert(StringRef name, InputFile *f);
std::vector<Symbol *> getSymsWithPrefix(StringRef prefix);
llvm::DenseMap<llvm::CachedHashStringRef, Symbol *> symMap;
std::unique_ptr<BitcodeCompiler> lto;
COFFLinkerContext &ctx;
std::vector<std::string> getSymbolLocations(ObjFile *file, uint32_t symIndex);
StringRef ltrim1(StringRef s, const char *chars);
} // namespace coff
} // namespace lld