1e6af15388
Mangling scheme varies on platform, and prepending an underscore is valid only on 32-bit x86. Added a method to mangle name to PECOFFLinkingContext and use it to avoid hard coding mangled names. llvm-svn: 190585
120 lines
3.8 KiB
C++
120 lines
3.8 KiB
C++
//===- lib/ReaderWriter/PECOFF/LinkerGeneratedSymbolFile.cpp --------------===//
|
|
//
|
|
// The LLVM Linker
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "Atoms.h"
|
|
#include "GroupedSectionsPass.h"
|
|
#include "IdataPass.h"
|
|
|
|
#include "llvm/ADT/SmallString.h"
|
|
#include "llvm/Support/Allocator.h"
|
|
#include "llvm/Support/Path.h"
|
|
#include "lld/Core/ArchiveLibraryFile.h"
|
|
#include "lld/Core/InputFiles.h"
|
|
#include "lld/Core/PassManager.h"
|
|
#include "lld/Passes/LayoutPass.h"
|
|
#include "lld/ReaderWriter/PECOFFLinkingContext.h"
|
|
#include "lld/ReaderWriter/Reader.h"
|
|
#include "lld/ReaderWriter/Simple.h"
|
|
#include "lld/ReaderWriter/Writer.h"
|
|
|
|
namespace lld {
|
|
namespace coff {
|
|
|
|
namespace {
|
|
|
|
// The symbol __ImageBase is a linker generated symbol. No standard library
|
|
// files define it, but the linker is expected to prepare it as if it was read
|
|
// from a file. The content of the atom is a 4-byte integer equal to the image
|
|
// base address. Note that because the name is prefixed by an underscore on x86
|
|
// Win32, the actual symbol name will be ___ImageBase (three underscores).
|
|
class ImageBaseAtom : public COFFLinkerInternalAtom {
|
|
public:
|
|
ImageBaseAtom(const PECOFFLinkingContext &context, const File &file,
|
|
uint32_t imageBase)
|
|
: COFFLinkerInternalAtom(file, assembleRawContent(imageBase)),
|
|
_name(context.decorateSymbol("__ImageBase")) {}
|
|
|
|
virtual StringRef name() const { return _name; }
|
|
virtual uint64_t ordinal() const { return 0; }
|
|
virtual ContentType contentType() const { return typeData; }
|
|
virtual ContentPermissions permissions() const { return permRW_; }
|
|
virtual DeadStripKind deadStrip() const { return deadStripAlways; }
|
|
|
|
private:
|
|
std::vector<uint8_t> assembleRawContent(uint32_t imageBase) {
|
|
std::vector<uint8_t> data = std::vector<uint8_t>(4);
|
|
*(reinterpret_cast<uint32_t *>(&data[0])) = imageBase;
|
|
return data;
|
|
}
|
|
|
|
StringRef _name;
|
|
};
|
|
|
|
// The file to wrap ImageBaseAtom. This is the only member file of
|
|
// LinkerGeneratedSymbolFile.
|
|
class MemberFile : public SimpleFile {
|
|
public:
|
|
MemberFile(const PECOFFLinkingContext &context)
|
|
: SimpleFile(context, "Member of the Linker Internal File"),
|
|
_atom(context, *this, context.getBaseAddress()) {
|
|
addAtom(_atom);
|
|
};
|
|
|
|
bool contains(StringRef name) const {
|
|
return _atom.name() == name;
|
|
}
|
|
|
|
private:
|
|
ImageBaseAtom _atom;
|
|
};
|
|
|
|
} // anonymous namespace
|
|
|
|
// A pseudo library file to wrap MemberFile, which in turn wraps ImageBaseAtom.
|
|
// The file the core linker handle is this.
|
|
//
|
|
// The reason why we don't pass MemberFile to the core linker is because, if we
|
|
// did so, ImageBaseAtom would always be emit to the resultant executable. By
|
|
// wrapping the file by a library file, we made it to emit ImageBaseAtom only
|
|
// when the atom is really referenced.
|
|
class LinkerGeneratedSymbolFile : public ArchiveLibraryFile {
|
|
public:
|
|
LinkerGeneratedSymbolFile(const PECOFFLinkingContext &context)
|
|
: ArchiveLibraryFile(context, "Linker Internal File"),
|
|
_memberFile(context) {};
|
|
|
|
virtual const File *find(StringRef name, bool dataSymbolOnly) const {
|
|
if (_memberFile.contains(name))
|
|
return &_memberFile;
|
|
return nullptr;
|
|
}
|
|
|
|
virtual const atom_collection<DefinedAtom> &defined() const {
|
|
return _noDefinedAtoms;
|
|
}
|
|
|
|
virtual const atom_collection<UndefinedAtom> &undefined() const {
|
|
return _noUndefinedAtoms;
|
|
}
|
|
|
|
virtual const atom_collection<SharedLibraryAtom> &sharedLibrary() const {
|
|
return _noSharedLibraryAtoms;
|
|
}
|
|
|
|
virtual const atom_collection<AbsoluteAtom> &absolute() const {
|
|
return _noAbsoluteAtoms;
|
|
}
|
|
|
|
private:
|
|
MemberFile _memberFile;
|
|
};
|
|
|
|
} // end namespace coff
|
|
} // end namespace lld
|