+++ /dev/null
-/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
- *
- * Copyright (c) 2005-2007 Apple Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-
-
-#ifndef __OBJECTFILE__
-#define __OBJECTFILE__
-
-#include <stdint.h>
-#include <vector>
-#include <map>
-
-
-
-//
-// These classes represent the abstract Atoms and References that are the basis of the linker.
-// An Atom and a Reference correspond to a Node and Edge in graph theory.
-//
-// A Reader is a class which parses an object file and presents it as Atoms and References.
-// All linking operations are done on Atoms and References. This makes the linker file
-// format independent.
-//
-// A Writer takes a vector of Atoms with all References resolved and produces an executable file.
-//
-//
-
-
-
-namespace ObjectFile {
-
-
-struct LineInfo
-{
- uint32_t atomOffset;
- const char* fileName;
- uint32_t lineNumber;
-};
-
-
-class ReaderOptions
-{
-public:
- ReaderOptions() : fFullyLoadArchives(false), fLoadAllObjcObjectsFromArchives(false), fFlatNamespace(false),
- fLinkingMainExecutable(false), fSlowx86Stubs(false),
- fForFinalLinkedImage(false), fForStatic(false), fForDyld(false), fMakeTentativeDefinitionsReal(false),
- fWhyLoad(false), fRootSafe(false), fSetuidSafe(false),fDebugInfoStripping(kDebugInfoFull),
- fImplicitlyLinkPublicDylibs(true), fLogObjectFiles(false), fLogAllFiles(false),
- fTraceDylibs(false), fTraceIndirectDylibs(false), fTraceArchives(false),
- fTraceOutputFile(NULL), fVersionMin(kMinUnset) {}
- enum DebugInfoStripping { kDebugInfoNone, kDebugInfoMinimal, kDebugInfoFull };
- enum VersionMin { kMinUnset, k10_1, k10_2, k10_3, k10_4, k10_5, k10_6 };
-
- struct AliasPair {
- const char* realName;
- const char* alias;
- };
-
- bool fFullyLoadArchives;
- bool fLoadAllObjcObjectsFromArchives;
- bool fFlatNamespace;
- bool fLinkingMainExecutable;
- bool fSlowx86Stubs;
- bool fForFinalLinkedImage;
- bool fForStatic;
- bool fForDyld;
- bool fMakeTentativeDefinitionsReal;
- bool fWhyLoad;
- bool fRootSafe;
- bool fSetuidSafe;
- DebugInfoStripping fDebugInfoStripping;
- bool fImplicitlyLinkPublicDylibs;
- bool fLogObjectFiles;
- bool fLogAllFiles;
- bool fTraceDylibs;
- bool fTraceIndirectDylibs;
- bool fTraceArchives;
- const char* fTraceOutputFile;
- VersionMin fVersionMin;
- std::vector<AliasPair> fAliases;
-};
-
-
-class Reader
-{
-public:
- enum DebugInfoKind { kDebugInfoNone=0, kDebugInfoStabs=1, kDebugInfoDwarf=2, kDebugInfoStabsUUID=3 };
- struct Stab
- {
- class Atom* atom;
- uint8_t type;
- uint8_t other;
- uint16_t desc;
- uint32_t value;
- const char* string;
- };
- enum ObjcConstraint { kObjcNone, kObjcRetainRelease, kObjcRetainReleaseOrGC, kObjcGC };
- enum CpuConstraint { kCpuAny = 0 };
-
- class DylibHander
- {
- public:
- virtual ~DylibHander() {}
- virtual Reader* findDylib(const char* installPath, const char* fromPath) = 0;
- };
-
-
- static Reader* createReader(const char* path, const ReaderOptions& options);
-
- virtual const char* getPath() = 0;
- virtual time_t getModificationTime() = 0;
- virtual DebugInfoKind getDebugInfoKind() = 0;
- virtual std::vector<class Atom*>& getAtoms() = 0;
- virtual std::vector<class Atom*>* getJustInTimeAtomsFor(const char* name) = 0;
- virtual std::vector<Stab>* getStabs() = 0;
- virtual ObjcConstraint getObjCConstraint() { return kObjcNone; }
- virtual uint32_t updateCpuConstraint(uint32_t current) { return current; }
- virtual bool objcReplacementClasses() { return false; }
-
- // For relocatable object files only
- virtual bool canScatterAtoms() { return true; }
- virtual void optimize(std::vector<ObjectFile::Atom*>&, std::vector<ObjectFile::Atom*>&,
- std::vector<const char*>&, uint32_t, ObjectFile::Reader* writer,
- bool allGlobalsAReDeadStripRoots, int okind,
- bool verbose, bool saveTemps, const char* outputFilePath,
- bool pie, bool allowTextRelocs) { }
- virtual bool hasLongBranchStubs() { return false; }
-
- // For Dynamic Libraries only
- virtual const char* getInstallPath() { return NULL; }
- virtual uint32_t getTimestamp() { return 0; }
- virtual uint32_t getCurrentVersion() { return 0; }
- virtual uint32_t getCompatibilityVersion() { return 0; }
- virtual void processIndirectLibraries(DylibHander* handler) { }
- virtual void setExplicitlyLinked() { }
- virtual bool explicitlyLinked() { return false; }
- virtual bool implicitlyLinked() { return false; }
- virtual bool providedExportAtom() { return false; }
- virtual const char* parentUmbrella() { return NULL; }
- virtual std::vector<const char*>* getAllowableClients() { return NULL; }
- virtual bool hasWeakExternals() { return false; }
- virtual bool isLazyLoadedDylib() { return false; }
-
-protected:
- Reader() {}
- virtual ~Reader() {}
-};
-
-class Segment
-{
-public:
- virtual const char* getName() const = 0;
- virtual bool isContentReadable() const = 0;
- virtual bool isContentWritable() const = 0;
- virtual bool isContentExecutable() const = 0;
-
- uint64_t getBaseAddress() const { return fBaseAddress; }
- void setBaseAddress(uint64_t addr) { fBaseAddress = addr; }
- virtual bool hasFixedAddress() const { return false; }
-
-protected:
- Segment() : fBaseAddress(0) {}
- virtual ~Segment() {}
- uint64_t fBaseAddress;
-};
-
-class Reference;
-
-class Section
-{
-public:
- unsigned int getIndex() { return fIndex; }
- uint64_t getBaseAddress() { return fBaseAddress; }
- void setBaseAddress(uint64_t addr) { fBaseAddress = addr; }
- void* fOther;
-
-protected:
- Section() : fOther(NULL), fBaseAddress(0), fIndex(0) {}
- uint64_t fBaseAddress;
- unsigned int fIndex;
-};
-
-
-struct Alignment
-{
- Alignment(int p2, int m=0) : powerOf2(p2), modulus(m) {}
- uint8_t trailingZeros() const { return (modulus==0) ? powerOf2 : __builtin_ctz(modulus); }
- uint16_t powerOf2;
- uint16_t modulus;
-};
-
-//
-// An atom is the fundamental unit of linking. A C function or global variable is an atom.
-// An atom has content and some attributes. The content of a function atom is the instructions
-// that implement the function. The content of a global variable atom is its initial bits.
-//
-// Name:
-// The name of an atom is the label name generated by the compiler. A C compiler names foo()
-// as _foo. A C++ compiler names foo() as __Z3foov.
-// The name refers to the first byte of the content. An atom cannot have multiple entry points.
-// Such code is modeled as multiple atoms, each having a "follow on" reference to the next.
-// A "follow on" reference is a contraint to the linker to the atoms must be laid out contiguously.
-//
-// Scope:
-// An atom is in one of three scopes: translation-unit, linkage-unit, or global. These correspond
-// to the C visibility of static, hidden, default.
-//
-// DefinitionKind:
-// An atom is one of five defintion kinds:
-// regular Most atoms.
-// weak C++ compiler makes some functions weak if there might be multiple copies
-// that the linker needs to coalesce.
-// tentative A straggler from ancient C when the extern did not exist. "int foo;" is ambiguous.
-// It could be a prototype or it could be a definition.
-// external This is a "proxy" atom produced by a dylib reader. It has no content. It exists
-// so that all References can be resolved.
-// external-weak Same as external, but the definition in the dylib is weak.
-//
-// SymbolTableInclusion:
-// An atom may or may not be in the symbol table in an object file.
-// in Most atoms for functions or global data
-// not-in Anonymous atoms such literal c-strings, or other compiler generated data
-// in-never-strip Atom whose name the strip tool should never remove (e.g. REFERENCED_DYNAMICALLY in mach-o)
-//
-// Ordinal:
-// When a reader is created it is given a base ordinal number. All atoms created by the reader
-// should return a contiguous range of ordinal values that start at the base ordinal. The ordinal
-// values are used by the linker to sort the atom graph when producing the output file.
-//
-class Atom
-{
-public:
- enum Scope { scopeTranslationUnit, scopeLinkageUnit, scopeGlobal };
- enum DefinitionKind { kRegularDefinition, kWeakDefinition, kTentativeDefinition, kExternalDefinition, kExternalWeakDefinition, kAbsoluteSymbol };
- enum SymbolTableInclusion { kSymbolTableNotIn, kSymbolTableIn, kSymbolTableInAndNeverStrip, kSymbolTableInAsAbsolute };
-
- virtual Reader* getFile() const = 0;
- virtual bool getTranslationUnitSource(const char** dir, const char** name) const = 0;
- virtual const char* getName() const = 0;
- virtual const char* getDisplayName() const = 0;
- virtual Scope getScope() const = 0;
- virtual DefinitionKind getDefinitionKind() const = 0;
- virtual SymbolTableInclusion getSymbolTableInclusion() const = 0;
- virtual bool dontDeadStrip() const = 0;
- virtual bool isZeroFill() const = 0;
- virtual bool isThumb() const = 0;
- virtual uint64_t getSize() const = 0;
- virtual std::vector<ObjectFile::Reference*>& getReferences() const = 0;
- virtual bool mustRemainInSection() const = 0;
- virtual const char* getSectionName() const = 0;
- virtual Segment& getSegment() const = 0;
- virtual Atom& getFollowOnAtom() const = 0;
- virtual uint32_t getOrdinal() const = 0;
- virtual std::vector<LineInfo>* getLineInfo() const = 0;
- virtual Alignment getAlignment() const = 0;
- virtual void copyRawContent(uint8_t buffer[]) const = 0;
- virtual void setScope(Scope) = 0;
-
-
- uint64_t getSectionOffset() const { return fSectionOffset; }
- uint64_t getAddress() const { return fSection->getBaseAddress() + fSectionOffset; }
- class Section* getSection() const { return fSection; }
-
- virtual void setSectionOffset(uint64_t offset) { fSectionOffset = offset; }
- virtual void setSection(class Section* sect) { fSection = sect; }
-
-protected:
- Atom() : fSectionOffset(0), fSection(NULL) {}
- virtual ~Atom() {}
-
- uint64_t fSectionOffset;
- class Section* fSection;
-};
-
-
-//
-// A Reference is a directed edge to another Atom. When an instruction in
-// the content of an Atom refers to another Atom, that is represented by a
-// Reference.
-//
-// There are two kinds of references: direct and by-name. With a direct Reference,
-// the target is bound by the Reader that created it. For instance a reference to a
-// static would produce a direct reference. A by-name reference requires the linker
-// to find the target Atom with the required name in order to be bound.
-//
-// For a link to succeed all References must be bound.
-//
-// A Reference has an optional "from" target. This is used when the content to fix-up
-// is the difference of two Atom address. For instance, if a pointer sized data Atom
-// is to contain A - B, then the Atom would have on Reference with a target of "A" and
-// a from-target of "B".
-//
-// A Reference also has a fix-up-offset. This is the offset into the content of the
-// Atom holding the reference where the fix-up (relocation) will be applied.
-//
-//
-//
-class Reference
-{
-public:
- enum TargetBinding { kUnboundByName, kBoundDirectly, kBoundByName, kDontBind };
-
- virtual TargetBinding getTargetBinding() const = 0;
- virtual TargetBinding getFromTargetBinding() const = 0;
- virtual uint8_t getKind() const = 0;
- virtual uint64_t getFixUpOffset() const = 0;
- virtual const char* getTargetName() const = 0;
- virtual Atom& getTarget() const = 0;
- virtual uint64_t getTargetOffset() const = 0;
- virtual Atom& getFromTarget() const = 0;
- virtual const char* getFromTargetName() const = 0;
- virtual uint64_t getFromTargetOffset() const = 0;
-
- virtual void setTarget(Atom&, uint64_t offset) = 0;
- virtual void setFromTarget(Atom&) = 0;
- virtual const char* getDescription() const = 0;
-
-protected:
- Reference() {}
- virtual ~Reference() {}
-};
-
-
-}; // namespace ObjectFile
-
-
-#endif // __OBJECTFILE__
projects / apple / ld64.git / blobdiff