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//===- COFFImportFile.h - COFF short import file implementation -*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// COFF short import file is a special kind of file which contains
// only symbol names for DLL-exported symbols. This class implements
// exporting of Symbols to create libraries and a SymbolicFile
// interface for the file type.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_OBJECT_COFFIMPORTFILE_H
#define LLVM_OBJECT_COFFIMPORTFILE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/IR/Mangler.h"
#include "llvm/Object/COFF.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/MemoryBufferRef.h"
#include "llvm/Support/raw_ostream.h"
namespace llvm {
namespace object {
constexpr std::string_view ImportDescriptorPrefix = "__IMPORT_DESCRIPTOR_";
constexpr std::string_view NullImportDescriptorSymbolName =
"__NULL_IMPORT_DESCRIPTOR";
constexpr std::string_view NullThunkDataPrefix = "\x7f";
constexpr std::string_view NullThunkDataSuffix = "_NULL_THUNK_DATA";
class COFFImportFile : public SymbolicFile {
private:
enum SymbolIndex { ImpSymbol, ThunkSymbol, ECAuxSymbol, ECThunkSymbol };
public:
COFFImportFile(MemoryBufferRef Source)
: SymbolicFile(ID_COFFImportFile, Source) {}
static bool classof(Binary const *V) { return V->isCOFFImportFile(); }
void moveSymbolNext(DataRefImpl &Symb) const override { ++Symb.p; }
Error printSymbolName(raw_ostream &OS, DataRefImpl Symb) const override;
Expected<uint32_t> getSymbolFlags(DataRefImpl Symb) const override {
return SymbolRef::SF_Global;
}
basic_symbol_iterator symbol_begin() const override {
return BasicSymbolRef(DataRefImpl(), this);
}
basic_symbol_iterator symbol_end() const override {
DataRefImpl Symb;
if (isData())
Symb.p = ImpSymbol + 1;
else if (COFF::isArm64EC(getMachine()))
Symb.p = ECThunkSymbol + 1;
else
Symb.p = ThunkSymbol + 1;
return BasicSymbolRef(Symb, this);
}
bool is64Bit() const override { return false; }
const coff_import_header *getCOFFImportHeader() const {
return reinterpret_cast<const object::coff_import_header *>(
Data.getBufferStart());
}
uint16_t getMachine() const { return getCOFFImportHeader()->Machine; }
StringRef getFileFormatName() const;
StringRef getExportName() const;
private:
bool isData() const {
return getCOFFImportHeader()->getType() == COFF::IMPORT_DATA;
}
};
struct COFFShortExport {
/// The name of the export as specified in the .def file or on the command
/// line, i.e. "foo" in "/EXPORT:foo", and "bar" in "/EXPORT:foo=bar". This
/// may lack mangling, such as underscore prefixing and stdcall suffixing.
std::string Name;
/// The external, exported name. Only non-empty when export renaming is in
/// effect, i.e. "foo" in "/EXPORT:foo=bar".
std::string ExtName;
/// The real, mangled symbol name from the object file. Given
/// "/export:foo=bar", this could be "_bar@8" if bar is stdcall.
std::string SymbolName;
/// Creates an import library entry that imports from a DLL export with a
/// different name. This is the name of the DLL export that should be
/// referenced when linking against this import library entry. In a .def
/// file, this is "baz" in "EXPORTS\nfoo = bar == baz".
std::string ImportName;
/// Specifies EXPORTAS name. In a .def file, this is "bar" in
/// "EXPORTS\nfoo EXPORTAS bar".
std::string ExportAs;
uint16_t Ordinal = 0;
bool Noname = false;
bool Data = false;
bool Private = false;
bool Constant = false;
friend bool operator==(const COFFShortExport &L, const COFFShortExport &R) {
return L.Name == R.Name && L.ExtName == R.ExtName &&
L.Ordinal == R.Ordinal && L.Noname == R.Noname &&
L.Data == R.Data && L.Private == R.Private;
}
friend bool operator!=(const COFFShortExport &L, const COFFShortExport &R) {
return !(L == R);
}
};
/// Writes a COFF import library containing entries described by the Exports
/// array.
///
/// For hybrid targets such as ARM64EC, additional native entry points can be
/// exposed using the NativeExports parameter. When NativeExports is used, the
/// output import library will expose these native ARM64 imports alongside the
/// entries described in the Exports array. Such a library can be used for
/// linking both ARM64EC and pure ARM64 objects, and the linker will pick only
/// the exports relevant to the target platform. For non-hybrid targets,
/// the NativeExports parameter should not be used.
Error writeImportLibrary(
StringRef ImportName, StringRef Path, ArrayRef<COFFShortExport> Exports,
COFF::MachineTypes Machine, bool MinGW,
ArrayRef<COFFShortExport> NativeExports = std::nullopt);
} // namespace object
} // namespace llvm
#endif
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