llvm-project/lld/COFF/Config.h

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//===- Config.h -------------------------------------------------*- C++ -*-===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLD_COFF_CONFIG_H
#define LLD_COFF_CONFIG_H
#include "llvm/ADT/StringRef.h"
#include "llvm/Object/COFF.h"
#include <cstdint>
#include <map>
#include <set>
#include <string>
namespace lld {
namespace coff {
using llvm::COFF::IMAGE_FILE_MACHINE_UNKNOWN;
using llvm::COFF::WindowsSubsystem;
using llvm::StringRef;
class DefinedAbsolute;
class DefinedRelative;
class StringChunk;
class Undefined;
// Short aliases.
static const auto AMD64 = llvm::COFF::IMAGE_FILE_MACHINE_AMD64;
static const auto ARMNT = llvm::COFF::IMAGE_FILE_MACHINE_ARMNT;
static const auto I386 = llvm::COFF::IMAGE_FILE_MACHINE_I386;
// Represents an /export option.
struct Export {
StringRef Name; // N in /export:N or /export:E=N
StringRef ExtName; // E in /export:E=N
Undefined *Sym = nullptr;
uint16_t Ordinal = 0;
bool Noname = false;
bool Data = false;
bool Private = false;
// If an export is a form of /export:foo=dllname.bar, that means
// that foo should be exported as an alias to bar in the DLL.
// ForwardTo is set to "dllname.bar" part. Usually empty.
StringRef ForwardTo;
StringChunk *ForwardChunk = nullptr;
COFF: Improve dllexported name mangling compatibility. The rules for dllexported symbols are overly complicated due to x86 name decoration, fuzzy symbol resolution, and the fact that one symbol can be resolved by so many different names. The rules are probably intended to be "intuitive", so that users don't have to understand the name mangling schemes, but it seems that it can lead to unintended symbol exports. To make it clear what I'm trying to do with this patch, let me write how the export rules are subtle and complicated. - x86 name decoration: If machine type is i386 and export name is given by a command line option, like /export:foo, the real symbol name the linker has to search for is _foo because all symbols are decorated with "_" prefixes. This doesn't happen on non-x86 machines. This automatic name decoration happens only when the name is not C++ mangled. However, the symbol name exported from DLLs are ones without "_" on all platforms. Moreover, if the option is given via .drectve section, no symbol decoration is done (the reason being that the .drectve section is created by a compiler and the compiler should always know the exact name of the symbol, I guess). - Fuzzy symbol resolution: In addition to x86 name decoration, the linker has to look for cdecl or C++ mangled symbols for a given /export. For example, it searches for not only _foo but also _foo@<number> or ??foo@... for /export:foo. Previous implementation didn't get it right. I'm trying to make it as compatible with MSVC linker as possible with this patch however the rules are. The new code looks a bit messy to me, but I don't think it can be simpler due to the ad-hoc-ness of the rules. llvm-svn: 246424
2015-08-31 16:43:21 +08:00
// True if this /export option was in .drectves section.
bool Directives = false;
StringRef SymbolName;
StringRef ExportName; // Name in DLL
bool operator==(const Export &E) {
return (Name == E.Name && ExtName == E.ExtName &&
Ordinal == E.Ordinal && Noname == E.Noname &&
Data == E.Data && Private == E.Private);
}
};
// Global configuration.
struct Configuration {
enum ManifestKind { SideBySide, Embed, No };
bool is64() { return Machine == AMD64; }
llvm::COFF::MachineTypes Machine = IMAGE_FILE_MACHINE_UNKNOWN;
bool Verbose = false;
WindowsSubsystem Subsystem = llvm::COFF::IMAGE_SUBSYSTEM_UNKNOWN;
Undefined *Entry = nullptr;
bool NoEntry = false;
std::string OutputFile;
bool DoGC = true;
bool DoICF = true;
bool Relocatable = true;
bool Force = false;
bool Debug = false;
bool WriteSymtab = true;
// Symbols in this set are considered as live by the garbage collector.
std::set<Undefined *> GCRoot;
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std::set<StringRef> NoDefaultLibs;
bool NoDefaultLibAll = false;
// True if we are creating a DLL.
bool DLL = false;
StringRef Implib;
std::vector<Export> Exports;
std::set<std::string> DelayLoads;
std::map<std::string, int> DLLOrder;
Undefined *DelayLoadHelper = nullptr;
// Used for SafeSEH.
DefinedRelative *SEHTable = nullptr;
DefinedAbsolute *SEHCount = nullptr;
// Used for /opt:lldlto=N
unsigned LTOOptLevel = 2;
// Used for /opt:lldltojobs=N
unsigned LTOJobs = 1;
// Used for /merge:from=to (e.g. /merge:.rdata=.text)
std::map<StringRef, StringRef> Merge;
// Options for manifest files.
ManifestKind Manifest = SideBySide;
int ManifestID = 1;
StringRef ManifestDependency;
bool ManifestUAC = true;
std::vector<std::string> ManifestInput;
StringRef ManifestLevel = "'asInvoker'";
StringRef ManifestUIAccess = "'false'";
StringRef ManifestFile;
// Used for /failifmismatch.
std::map<StringRef, StringRef> MustMatch;
// Used for /alternatename.
std::map<StringRef, StringRef> AlternateNames;
uint64_t ImageBase = -1;
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uint64_t StackReserve = 1024 * 1024;
uint64_t StackCommit = 4096;
uint64_t HeapReserve = 1024 * 1024;
uint64_t HeapCommit = 4096;
uint32_t MajorImageVersion = 0;
uint32_t MinorImageVersion = 0;
uint32_t MajorOSVersion = 6;
uint32_t MinorOSVersion = 0;
bool DynamicBase = true;
bool AllowBind = true;
bool NxCompat = true;
bool AllowIsolation = true;
bool TerminalServerAware = true;
bool LargeAddressAware = false;
bool HighEntropyVA = false;
};
extern Configuration *Config;
} // namespace coff
} // namespace lld
#endif