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--- dyld/dyld-750.6/dyld3/shared-cache/OptimizerObjC.cpp
+++ /dev/null
@@ -1,1122 +0,0 @@
-/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
- *
- * Copyright (c) 2014 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@
- */
-
-
-#include <dirent.h>
-#include <sys/errno.h>
-#include <sys/fcntl.h>
-#include <mach-o/loader.h>
-#include <mach-o/fat.h>
-#include <assert.h>
-
-#include "DyldSharedCache.h"
-#include "Diagnostics.h"
-#include "SharedCacheBuilder.h"
-#include "FileAbstraction.hpp"
-#include "MachOFileAbstraction.hpp"
-#include "MachOLoaded.h"
-#include "MachOAnalyzer.h"
-
-#ifndef MH_HAS_OBJC
- #define MH_HAS_OBJC 0x40000000
-#endif
-
-// Scan a C++ or Swift length-mangled field.
-static bool scanMangledField(const char *&string, const char *end,
- const char *&field, int& length)
-{
- // Leading zero not allowed.
- if (*string == '0') return false;
-
- length = 0;
- field = string;
- while (field < end) {
- char c = *field;
- if (!isdigit(c)) break;
- field++;
- if (__builtin_smul_overflow(length, 10, &length)) return false;
- if (__builtin_sadd_overflow(length, c - '0', &length)) return false;
- }
-
- string = field + length;
- return length > 0 && string <= end;
-}
-
-
-// copySwiftDemangledName
-// Returns the pretty form of the given Swift-mangled class or protocol name.
-// Returns nullptr if the string doesn't look like a mangled Swift name.
-// The result must be freed with free().
-static char *copySwiftDemangledName(const char *string, bool isProtocol = false)
-{
- if (!string) return nullptr;
-
- // Swift mangling prefix.
- if (strncmp(string, isProtocol ? "_TtP" : "_TtC", 4) != 0) return nullptr;
- string += 4;
-
- const char *end = string + strlen(string);
-
- // Module name.
- const char *prefix;
- int prefixLength;
- if (string[0] == 's') {
- // "s" is the Swift module.
- prefix = "Swift";
- prefixLength = 5;
- string += 1;
- } else {
- if (! scanMangledField(string, end, prefix, prefixLength)) return nullptr;
- }
-
- // Class or protocol name.
- const char *suffix;
- int suffixLength;
- if (! scanMangledField(string, end, suffix, suffixLength)) return nullptr;
-
- if (isProtocol) {
- // Remainder must be "_".
- if (strcmp(string, "_") != 0) return nullptr;
- } else {
- // Remainder must be empty.
- if (string != end) return nullptr;
- }
-
- char *result;
- asprintf(&result, "%.*s.%.*s", prefixLength,prefix, suffixLength,suffix);
- return result;
-}
-
-
-class ContentAccessor {
-public:
- ContentAccessor(const DyldSharedCache* cache, Diagnostics& diag)
- : _diagnostics(diag)
- {
- _cacheStart = (uint8_t*)cache;
- _cacheUnslideAddr = cache->unslidLoadAddress();
- _slide = (uint64_t)cache - _cacheUnslideAddr;
- }
-
- // Converts from an on disk vmAddr to the real vmAddr
- // That is, for a chained fixup, decodes the chain, for a non-chained fixup, does nothing.
- uint64_t vmAddrForOnDiskVMAddr(uint64_t vmaddr) {
- return vmaddr;
- }
-
- void* contentForVMAddr(uint64_t vmaddr) {
- vmaddr = vmAddrForOnDiskVMAddr(vmaddr);
- if ( vmaddr != 0 ) {
- uint64_t offset = vmaddr - _cacheUnslideAddr;
- return _cacheStart + offset;
- } else
- return nullptr;
- }
-
- uint64_t vmAddrForContent(const void* content) {
- if ( content != nullptr )
- return _cacheUnslideAddr + ((uint8_t*)content - _cacheStart);
- else
- return 0;
- }
-
- Diagnostics& diagnostics() { return _diagnostics; }
-
-private:
- Diagnostics& _diagnostics;
- uint64_t _slide;
- uint64_t _cacheUnslideAddr;
- uint8_t* _cacheStart;
-};
-
-
-// Access a section containing a list of pointers
-template <typename P, typename T>
-class PointerSection
-{
- typedef typename P::uint_t pint_t;
-public:
- PointerSection(ContentAccessor* cache, const macho_header<P>* mh,
- const char* segname, const char* sectname)
- : _cache(cache),
- _section(mh->getSection(segname, sectname)),
- _base(_section ? (pint_t*)cache->contentForVMAddr(_section->addr()) : 0),
- _count(_section ? (pint_t)(_section->size() / sizeof(pint_t)) : 0) {
- }
-
- pint_t count() const { return _count; }
-
- pint_t getVMAddress(pint_t index) const {
- if ( index >= _count ) {
- _cache->diagnostics().error("index out of range in section %s", _section->sectname());
- return 0;
- }
- return (pint_t)P::getP(_base[index]);
- }
-
- pint_t getSectionVMAddress() const {
- return (pint_t)_section->addr();
- }
-
- T get(pint_t index) const {
- return (T)_cache->contentForVMAddr(getVMAddress(index));
- }
-
- void setVMAddress(pint_t index, pint_t value) {
- if ( index >= _count ) {
- _cache->diagnostics().error("index out of range in section %s", _section->sectname());
- return;
- }
- P::setP(_base[index], value);
- }
-
- void removeNulls() {
- pint_t shift = 0;
- for (pint_t i = 0; i < _count; i++) {
- pint_t value = _base[i];
- if (value) {
- _base[i-shift] = value;
- } else {
- shift++;
- }
- }
- _count -= shift;
- const_cast<macho_section<P>*>(_section)->set_size(_count * sizeof(pint_t));
- }
-
-private:
- ContentAccessor* const _cache;
- const macho_section<P>* const _section;
- pint_t* const _base;
- pint_t const _count;
-};
-
-
-// Access a section containing an array of structures
-template <typename P, typename T>
-class ArraySection
-{
-public:
- ArraySection(ContentAccessor* cache, const macho_header<P>* mh,
- const char *segname, const char *sectname)
- : _cache(cache),
- _section(mh->getSection(segname, sectname)),
- _base(_section ? (T *)cache->contentForVMAddr(_section->addr()) : 0),
- _count(_section ? _section->size() / sizeof(T) : 0) {
- }
-
- uint64_t count() const { return _count; }
-
- T& get(uint64_t index) const {
- if (index >= _count) {
- _cache->diagnostics().error("index out of range in section %s", _section->sectname());
- }
- return _base[index];
- }
-
-private:
- ContentAccessor* const _cache;
- const macho_section<P>* const _section;
- T * const _base;
- uint64_t const _count;
-};
-
-
-#define SELOPT_WRITE
-#include "objc-shared-cache.h"
-#include "ObjC1Abstraction.hpp"
-#include "ObjC2Abstraction.hpp"
-
-
-namespace {
-
-
-
-template <typename P>
-class ObjCSelectorUniquer
-{
-public:
- typedef typename P::uint_t pint_t;
-
- ObjCSelectorUniquer(ContentAccessor* cache) : _cache(cache) { }
-
- pint_t visit(pint_t oldValue)
- {
- _count++;
- const char *s = (const char *)_cache->contentForVMAddr(oldValue);
- oldValue = (pint_t)_cache->vmAddrForOnDiskVMAddr(oldValue);
- objc_opt::string_map::iterator element =
- _selectorStrings.insert(objc_opt::string_map::value_type(s, oldValue)).first;
- return (pint_t)element->second;
- }
-
- void visitCoalescedStrings(const CacheBuilder::CacheCoalescedText& coalescedText) {
- const CacheBuilder::CacheCoalescedText::StringSection& methodNames = coalescedText.getSectionData("__objc_methname");
- for (const auto& stringAndOffset : methodNames.stringsToOffsets) {
- uint64_t vmAddr = methodNames.bufferVMAddr + stringAndOffset.second;
- _selectorStrings[stringAndOffset.first.data()] = vmAddr;
- }
- }
-
- objc_opt::string_map& strings() {
- return _selectorStrings;
- }
-
- size_t count() const { return _count; }
-
-private:
- objc_opt::string_map _selectorStrings;
- ContentAccessor* _cache;
- size_t _count = 0;
-};
-
-
-template <typename P>
-class ClassListBuilder
-{
-private:
- objc_opt::string_map _classNames;
- objc_opt::class_map _classes;
- size_t _count = 0;
- HeaderInfoOptimizer<P, objc_header_info_ro_t<P>>& _hInfos;
-
-public:
-
- ClassListBuilder(HeaderInfoOptimizer<P, objc_header_info_ro_t<P>>& hinfos) : _hInfos(hinfos) { }
-
- void visitClass(ContentAccessor* cache,
- const macho_header<P>* header,
- objc_class_t<P>* cls)
- {
- if (cls->isMetaClass(cache)) return;
-
- const char *name = cls->getName(cache);
- uint64_t name_vmaddr = cache->vmAddrForContent((void*)name);
- uint64_t cls_vmaddr = cache->vmAddrForContent(cls);
- uint64_t hinfo_vmaddr = cache->vmAddrForContent(_hInfos.hinfoForHeader(cache, header));
- _classNames.insert(objc_opt::string_map::value_type(name, name_vmaddr));
- _classes.insert(objc_opt::class_map::value_type(name, std::pair<uint64_t, uint64_t>(cls_vmaddr, hinfo_vmaddr)));
- _count++;
- }
-
- objc_opt::string_map& classNames() {
- return _classNames;
- }
-
- objc_opt::class_map& classes() {
- return _classes;
- }
-
- size_t count() const { return _count; }
-};
-
-template <typename P>
-class ProtocolOptimizer
-{
-private:
- typedef typename P::uint_t pint_t;
-
- objc_opt::string_map _protocolNames;
- objc_opt::legacy_protocol_map _protocols;
- objc_opt::protocol_map _protocolsAndHeaders;
- size_t _protocolCount;
- size_t _protocolReferenceCount;
- Diagnostics& _diagnostics;
- HeaderInfoOptimizer<P, objc_header_info_ro_t<P>>& _hInfos;
-
- friend class ProtocolReferenceWalker<P, ProtocolOptimizer<P>>;
-
- pint_t visitProtocolReference(ContentAccessor* cache, pint_t oldValue)
- {
- objc_protocol_t<P>* proto = (objc_protocol_t<P>*)
- cache->contentForVMAddr(oldValue);
- pint_t newValue = (pint_t)_protocols[proto->getName(cache)];
- if (oldValue != newValue) _protocolReferenceCount++;
- return newValue;
- }
-
-public:
-
- ProtocolOptimizer(Diagnostics& diag, HeaderInfoOptimizer<P, objc_header_info_ro_t<P>>& hinfos)
- : _protocolCount(0), _protocolReferenceCount(0), _diagnostics(diag), _hInfos(hinfos) {
- }
-
- void addProtocols(ContentAccessor* cache, const macho_header<P>* header)
- {
- PointerSection<P, objc_protocol_t<P> *>
- protocols(cache, header, "__DATA", "__objc_protolist");
-
- for (pint_t i = 0; i < protocols.count(); i++) {
- objc_protocol_t<P> *proto = protocols.get(i);
-
- const char *name = proto->getName(cache);
- if (_protocolNames.count(name) == 0) {
- if (proto->getSize() > sizeof(objc_protocol_t<P>)) {
- _diagnostics.error("objc protocol is too big");
- return;
- }
- uint64_t name_vmaddr = cache->vmAddrForContent((void*)name);
- uint64_t proto_vmaddr = cache->vmAddrForContent(proto);
- _protocolNames.insert(objc_opt::string_map::value_type(name, name_vmaddr));
- _protocols.insert(objc_opt::legacy_protocol_map::value_type(name, proto_vmaddr));
- _protocolCount++;
- }
-
- // Note down which header this protocol came from. We'll fill in the proto_vmaddr here later
- // once we've chosen a single definition for the protocol with this name.
- uint64_t hinfo_vmaddr = cache->vmAddrForContent(_hInfos.hinfoForHeader(cache, header));
- _protocolsAndHeaders.insert(objc_opt::class_map::value_type(name, std::pair<uint64_t, uint64_t>(0, hinfo_vmaddr)));
- }
- }
-
- const char *writeProtocols(ContentAccessor* cache,
- uint8_t *& rwdest, size_t& rwremaining,
- uint8_t *& rodest, size_t& roremaining,
- CacheBuilder::ASLR_Tracker& aslrTracker,
- pint_t protocolClassVMAddr)
- {
- if (_protocolCount == 0) return NULL;
-
- if (protocolClassVMAddr == 0) {
- return "libobjc's Protocol class symbol not found (metadata not optimized)";
- }
-
- size_t rwrequired = _protocolCount * sizeof(objc_protocol_t<P>);
- if (rwremaining < rwrequired) {
- return "libobjc's read-write section is too small (metadata not optimized)";
- }
-
- for (auto iter = _protocols.begin(); iter != _protocols.end(); ++iter)
- {
- objc_protocol_t<P>* oldProto = (objc_protocol_t<P>*)
- cache->contentForVMAddr(iter->second);
-
- // Create a new protocol object.
- objc_protocol_t<P>* proto = (objc_protocol_t<P>*)rwdest;
- rwdest += sizeof(*proto);
- rwremaining -= sizeof(*proto);
-
- // Initialize it.
- uint32_t oldSize = oldProto->getSize();
- memcpy(proto, oldProto, oldSize);
- if (!proto->getIsaVMAddr()) {
- proto->setIsaVMAddr(protocolClassVMAddr);
- }
- if (oldSize < sizeof(*proto)) {
- // Protocol object is old. Populate new fields.
- proto->setSize(sizeof(objc_protocol_t<P>));
- // missing extendedMethodTypes is already nil
- }
- // Some protocol objects are big enough to have the
- // demangledName field but don't initialize it.
- // Initialize it here if it is not already set.
- if (!proto->getDemangledName(cache)) {
- const char *roName = proto->getName(cache);
- char *demangledName = copySwiftDemangledName(roName, true);
- if (demangledName) {
- size_t length = 1 + strlen(demangledName);
- if (roremaining < length) {
- return "libobjc's read-only section is too small (metadata not optimized)";
- }
-
- memmove(rodest, demangledName, length);
- roName = (const char *)rodest;
- rodest += length;
- roremaining -= length;
-
- free(demangledName);
- }
- proto->setDemangledName(cache, roName, _diagnostics);
- }
- proto->setFixedUp();
- proto->setIsCanonical();
-
- // Redirect the protocol table at our new object.
- iter->second = cache->vmAddrForContent(proto);
-
- // Add new rebase entries.
- proto->addPointers(cache, aslrTracker);
- }
-
- // Now that we've chosen the canonical protocols, set the duplicate headers to
- // point to their protocols.
- for (auto iter = _protocolsAndHeaders.begin(); iter != _protocolsAndHeaders.end(); ++iter) {
- iter->second.first = _protocols[iter->first];
- }
-
- return NULL;
- }
-
- void updateReferences(ContentAccessor* cache, const macho_header<P>* header)
- {
- ProtocolReferenceWalker<P, ProtocolOptimizer<P>> refs(*this);
- refs.walk(cache, header);
- }
-
- objc_opt::string_map& protocolNames() {
- return _protocolNames;
- }
-
- objc_opt::legacy_protocol_map& protocols() {
- return _protocols;
- }
-
- objc_opt::protocol_map& protocolsAndHeaders() {
- return _protocolsAndHeaders;
- }
-
- size_t protocolCount() const { return _protocolCount; }
- size_t protocolReferenceCount() const { return _protocolReferenceCount; }
-};
-
-
-static int percent(size_t num, size_t denom) {
- if (denom)
- return (int)(num / (double)denom * 100);
- else
- return 100;
-}
-
-template <typename P>
-void addObjcSegments(Diagnostics& diag, DyldSharedCache* cache, const mach_header* libobjcMH,
- uint8_t* objcReadOnlyBuffer, uint64_t objcReadOnlyBufferSizeAllocated,
- uint8_t* objcReadWriteBuffer, uint64_t objcReadWriteBufferSizeAllocated,
- uint32_t objcRwFileOffset)
-{
- // validate there is enough free space to add the load commands
- const dyld3::MachOAnalyzer* libobjcMA = ((dyld3::MachOAnalyzer*)libobjcMH);
- uint32_t freeSpace = libobjcMA->loadCommandsFreeSpace();
- const uint32_t segSize = sizeof(macho_segment_command<P>);
- if ( freeSpace < 2*segSize ) {
- diag.warning("not enough space in libojbc.dylib to add load commands for objc optimization regions");
- return;
- }
-
- // find location of LINKEDIT LC_SEGMENT load command, we need to insert new segments before it
- __block uint8_t* linkeditSeg = nullptr;
- libobjcMA->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& info, bool& stop) {
- if ( strcmp(info.segName, "__LINKEDIT") == 0 )
- linkeditSeg = (uint8_t*)libobjcMH + info.loadCommandOffset;
- });
- if ( linkeditSeg == nullptr ) {
- diag.warning("__LINKEDIT not found in libojbc.dylib");
- return;
- }
-
- // move load commands to make room to insert two new ones before LINKEDIT segment load command
- uint8_t* endOfLoadCommands = (uint8_t*)libobjcMH + sizeof(macho_header<P>) + libobjcMH->sizeofcmds;
- uint32_t remainingSize = (uint32_t)(endOfLoadCommands - linkeditSeg);
- memmove(linkeditSeg+2*segSize, linkeditSeg, remainingSize);
-
- // insert new segments
- macho_segment_command<P>* roSeg = (macho_segment_command<P>*)(linkeditSeg);
- macho_segment_command<P>* rwSeg = (macho_segment_command<P>*)(linkeditSeg+sizeof(macho_segment_command<P>));
- roSeg->set_cmd(macho_segment_command<P>::CMD);
- roSeg->set_cmdsize(segSize);
- roSeg->set_segname("__OBJC_RO");
- roSeg->set_vmaddr(cache->unslidLoadAddress() + objcReadOnlyBuffer - (uint8_t*)cache);
- roSeg->set_vmsize(objcReadOnlyBufferSizeAllocated);
- roSeg->set_fileoff(objcReadOnlyBuffer - (uint8_t*)cache);
- roSeg->set_filesize(objcReadOnlyBufferSizeAllocated);
- roSeg->set_maxprot(VM_PROT_READ);
- roSeg->set_initprot(VM_PROT_READ);
- roSeg->set_nsects(0);
- roSeg->set_flags(0);
- rwSeg->set_cmd(macho_segment_command<P>::CMD);
- rwSeg->set_cmdsize(segSize);
- rwSeg->set_segname("__OBJC_RW");
- rwSeg->set_vmaddr(cache->unslidLoadAddress() + objcReadWriteBuffer - (uint8_t*)cache);
- rwSeg->set_vmsize(objcReadWriteBufferSizeAllocated);
- rwSeg->set_fileoff(objcRwFileOffset);
- rwSeg->set_filesize(objcReadWriteBufferSizeAllocated);
- rwSeg->set_maxprot(VM_PROT_WRITE|VM_PROT_READ);
- rwSeg->set_initprot(VM_PROT_WRITE|VM_PROT_READ);
- rwSeg->set_nsects(0);
- rwSeg->set_flags(0);
-
- // update mach_header to account for new load commands
- macho_header<P>* mh = (macho_header<P>*)libobjcMH;
- mh->set_sizeofcmds(mh->sizeofcmds() + 2*segSize);
- mh->set_ncmds(mh->ncmds()+2);
-
- // fix up table at start of dyld cache that has pointer into install name for libobjc
- dyld_cache_image_info* images = (dyld_cache_image_info*)((uint8_t*)cache + cache->header.imagesOffset);
- uint64_t libobjcUnslidAddress = cache->unslidLoadAddress() + ((uint8_t*)libobjcMH - (uint8_t*)cache);
- for (uint32_t i=0; i < cache->header.imagesCount; ++i) {
- if ( images[i].address == libobjcUnslidAddress ) {
- images[i].pathFileOffset += (2*segSize);
- break;
- }
- }
-}
-
-
-template <typename P>
-void doOptimizeObjC(DyldSharedCache* cache, bool forProduction, CacheBuilder::ASLR_Tracker& aslrTracker,
- CacheBuilder::LOH_Tracker& lohTracker, const CacheBuilder::CacheCoalescedText& coalescedText,
- const std::map<void*, std::string>& missingWeakImports, Diagnostics& diag,
- uint8_t* objcReadOnlyBuffer, uint64_t objcReadOnlyBufferSizeUsed, uint64_t objcReadOnlyBufferSizeAllocated,
- uint8_t* objcReadWriteBuffer, uint64_t objcReadWriteBufferSizeAllocated,
- uint32_t objcRwFileOffset)
-{
- typedef typename P::E E;
- typedef typename P::uint_t pint_t;
-
- diag.verbose("Optimizing objc metadata:\n");
- diag.verbose(" cache type is %s\n", forProduction ? "production" : "development");
-
- ContentAccessor cacheAccessor(cache, diag);
-
- size_t headerSize = P::round_up(sizeof(objc_opt::objc_opt_t));
- if (headerSize != sizeof(objc_opt::objc_opt_t)) {
- diag.warning("libobjc's optimization structure size is wrong (metadata not optimized)");
- }
-
- //
- // Find libobjc's empty sections and build list of images with objc metadata
- //
- __block const mach_header* libobjcMH = nullptr;
- __block const macho_section<P> *optROSection = nullptr;
- __block const macho_section<P> *optPointerListSection = nullptr;
- __block std::vector<const macho_header<P>*> objcDylibs;
- cache->forEachImage(^(const mach_header* machHeader, const char* installName) {
- const macho_header<P>* mh = (const macho_header<P>*)machHeader;
- if ( strstr(installName, "/libobjc.") != nullptr ) {
- libobjcMH = (mach_header*)mh;
- optROSection = mh->getSection("__TEXT", "__objc_opt_ro");
- optPointerListSection = mh->getSection("__DATA", "__objc_opt_ptrs");
- }
- if ( mh->getSection("__DATA", "__objc_imageinfo") || mh->getSection("__OBJC", "__image_info") ) {
- objcDylibs.push_back(mh);
- }
- // log("installName %s at mhdr 0x%016lx", installName, (uintptr_t)cacheAccessor.vmAddrForContent((void*)mh));
- });
- if ( optROSection == nullptr ) {
- diag.warning("libobjc's read-only section missing (metadata not optimized)");
- return;
- }
- if ( optPointerListSection == nullptr ) {
- diag.warning("libobjc's pointer list section missing (metadata not optimized)");
- return;
- }
- // point optROData into space allocated in dyld cache
- uint8_t* optROData = objcReadOnlyBuffer + objcReadOnlyBufferSizeUsed;
- size_t optRORemaining = objcReadOnlyBufferSizeAllocated - objcReadOnlyBufferSizeUsed;
- *((uint32_t*)optROData) = objc_opt::VERSION;
- if ( optROData == nullptr ) {
- diag.warning("libobjc's read-only section has bad content");
- return;
- }
-
- uint8_t* optRWData = objcReadWriteBuffer;
- size_t optRWRemaining = objcReadWriteBufferSizeAllocated;
- if (optRORemaining < headerSize) {
- diag.warning("libobjc's read-only section is too small (metadata not optimized)");
- return;
- }
- objc_opt::objc_opt_t* optROHeader = (objc_opt::objc_opt_t *)optROData;
- optROData += headerSize;
- optRORemaining -= headerSize;
- if (E::get32(optROHeader->version) != objc_opt::VERSION) {
- diag.warning("libobjc's read-only section version is unrecognized (metadata not optimized)");
- return;
- }
-
- if (optPointerListSection->size() < sizeof(objc_opt::objc_opt_pointerlist_tt<pint_t>)) {
- diag.warning("libobjc's pointer list section is too small (metadata not optimized)");
- return;
- }
- const objc_opt::objc_opt_pointerlist_tt<pint_t> *optPointerList = (const objc_opt::objc_opt_pointerlist_tt<pint_t> *)cacheAccessor.contentForVMAddr(optPointerListSection->addr());
-
- // Write nothing to optROHeader until everything else is written.
- // If something fails below, libobjc will not use the section.
-
-
- //
- // Make copy of objcList and sort that list.
- //
- std::vector<const macho_header<P>*> addressSortedDylibs = objcDylibs;
- std::sort(addressSortedDylibs.begin(), addressSortedDylibs.end(), [](const macho_header<P>* lmh, const macho_header<P>* rmh) -> bool {
- return lmh < rmh;
- });
-
- //
- // Build HeaderInfo list in cache
- //
- // First the RO header info
- // log("writing out %d RO dylibs at offset %d", (uint32_t)objcDylibs.size(), (uint32_t)(optROSection->size() - optRORemaining));
- uint64_t hinfoROVMAddr = cacheAccessor.vmAddrForContent(optROData);
- HeaderInfoOptimizer<P, objc_header_info_ro_t<P>> hinfoROOptimizer;
- const char* err = hinfoROOptimizer.init((uint32_t)objcDylibs.size(), optROData, optRORemaining);
- if (err) {
- diag.warning("%s", err);
- return;
- }
- else {
- for (const macho_header<P>* mh : addressSortedDylibs) {
- hinfoROOptimizer.update(&cacheAccessor, mh, aslrTracker);
- }
- }
-
- // Then the RW header info
- // log("writing out %d RW dylibs at offset %d", (uint32_t)objcDylibs.size(), (uint32_t)(optRWSection->size() - optRWRemaining));
- uint64_t hinfoRWVMAddr = cacheAccessor.vmAddrForContent(optRWData);
- HeaderInfoOptimizer<P, objc_header_info_rw_t<P>> hinfoRWOptimizer;
- err = hinfoRWOptimizer.init((uint32_t)objcDylibs.size(), optRWData, optRWRemaining);
- if (err) {
- diag.warning("%s", err);
- return;
- }
- else {
- for (const macho_header<P>* mh : addressSortedDylibs) {
- hinfoRWOptimizer.update(&cacheAccessor, mh, aslrTracker);
- }
- }
-
- //
- // Update selector references and build selector list
- //
- // This is SAFE: if we run out of room for the selector table,
- // the modified binaries are still usable.
- //
- // Heuristic: choose selectors from libraries with more selector cstring data first.
- // This tries to localize selector cstring memory.
- //
- ObjCSelectorUniquer<P> uniq(&cacheAccessor);
- std::vector<const macho_header<P>*> sizeSortedDylibs = objcDylibs;
- std::sort(sizeSortedDylibs.begin(), sizeSortedDylibs.end(), [](const macho_header<P>* lmh, const macho_header<P>* rmh) -> bool {
- // Sort a select few heavy hitters first.
- auto getPriority = [](const char* installName) -> int {
- if (!strcmp(installName, "/usr/lib/libobjc.A.dylib"))
- return 0;
- if (!strcmp(installName, "/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation") ||
- !strcmp(installName, "/System/Library/Frameworks/Foundation.framework/Foundation"))
- return 1;
- if (!strcmp(installName, "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation") ||
- !strcmp(installName, "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation"))
- return 2;
- // Note we don't sort iOSMac UIKitCore early as we want iOSMac after macOS.
- if (!strcmp(installName, "/System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore"))
- return 3;
- if (!strcmp(installName, "/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit"))
- return 4;
- if (!strcmp(installName, "/System/Library/Frameworks/CFNetwork.framework/Versions/A/CFNetwork") ||
- !strcmp(installName, "/System/Library/Frameworks/CFNetwork.framework/CFNetwork"))
- return 5;
- return INT_MAX;
- };
-
- // Sort by priority first
- int priorityA = getPriority(((const dyld3::MachOFile*)lmh)->installName());
- int priorityB = getPriority(((const dyld3::MachOFile*)rmh)->installName());
- if (priorityA != priorityB)
- return priorityA < priorityB;
-
- // Sort mac before iOSMac
- bool isIOSMacA = strncmp(((const dyld3::MachOFile*)lmh)->installName(), "/System/iOSSupport/", 19) == 0;
- bool isIOSMacB = strncmp(((const dyld3::MachOFile*)rmh)->installName(), "/System/iOSSupport/", 19) == 0;
- if (isIOSMacA != isIOSMacB)
- return !isIOSMacA;
-
- const macho_section<P>* lSection = lmh->getSection("__TEXT", "__objc_methname");
- const macho_section<P>* rSection = rmh->getSection("__TEXT", "__objc_methname");
- uint64_t lSelectorSize = (lSection ? lSection->size() : 0);
- uint64_t rSelectorSize = (rSection ? rSection->size() : 0);
- return lSelectorSize > rSelectorSize;
- });
-
- auto alignPointer = [](uint8_t* ptr) -> uint8_t* {
- return (uint8_t*)(((uintptr_t)ptr + 0x7) & ~0x7);
- };
-
- SelectorOptimizer<P, ObjCSelectorUniquer<P> > selOptimizer(uniq);
- selOptimizer.visitCoalescedStrings(coalescedText);
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- LegacySelectorUpdater<P, ObjCSelectorUniquer<P>>::update(&cacheAccessor, mh, uniq);
- selOptimizer.optimize(&cacheAccessor, mh);
- }
-
- diag.verbose(" uniqued %6lu selectors\n", uniq.strings().size());
- diag.verbose(" updated %6lu selector references\n", uniq.count());
-
- uint64_t seloptVMAddr = cacheAccessor.vmAddrForContent(optROData);
- objc_opt::objc_selopt_t *selopt = new(optROData) objc_opt::objc_selopt_t;
- err = selopt->write(seloptVMAddr, optRORemaining, uniq.strings());
- if (err) {
- diag.warning("%s", err);
- return;
- }
- optROData += selopt->size();
- optROData = alignPointer(optROData);
- optRORemaining -= selopt->size();
- uint32_t seloptCapacity = selopt->capacity;
- uint32_t seloptOccupied = selopt->occupied;
- selopt->byteswap(E::little_endian), selopt = nullptr;
-
- diag.verbose(" selector table occupancy %u/%u (%u%%)\n",
- seloptOccupied, seloptCapacity,
- (unsigned)(seloptOccupied/(double)seloptCapacity*100));
-
-
- //
- // Detect classes that have missing weak-import superclasses.
- //
- // Production shared caches don't support roots so we can set this and know
- // there will definitely not be missing weak superclasses at runtime.
- // Development shared caches can set this bit as the objc runtime only trusts
- // this bit if there are no roots at runtime.
- //
- // This is SAFE: the binaries themselves are unmodified.
- WeakClassDetector<P> weakopt;
- bool noMissingWeakSuperclasses = weakopt.noMissingWeakSuperclasses(&cacheAccessor,
- missingWeakImports,
- sizeSortedDylibs);
-
- if (forProduction) {
- // Shared cache does not currently support unbound weak references.
- // Here we assert that there are none. If support is added later then
- // this assertion needs to be removed and this path needs to be tested.
- // FIXME: The internal cache also isn't going to notice that an on-disk
- // dylib could resolve a weak bind from the shared cache. Should we just
- // error on all caches, regardless of dev/customer?
- if (!noMissingWeakSuperclasses) {
- diag.error("Some Objective-C class has a superclass that is "
- "weak-import and missing from the cache.");
- }
- }
-
-
- //
- // Build class table.
- //
- // This is SAFE: the binaries themselves are unmodified.
- ClassListBuilder<P> classes(hinfoROOptimizer);
- ClassWalker<P, ClassListBuilder<P>> classWalker(classes);
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- classWalker.walk(&cacheAccessor, mh);
- }
-
- diag.verbose(" recorded % 6ld classes\n", classes.classNames().size());
-
- uint64_t clsoptVMAddr = cacheAccessor.vmAddrForContent(optROData);
- objc_opt::objc_clsopt_t *clsopt = new(optROData) objc_opt::objc_clsopt_t;
- err = clsopt->write(clsoptVMAddr, optRORemaining,
- classes.classNames(), classes.classes(), false);
- if (err) {
- diag.warning("%s", err);
- return;
- }
- optROData += clsopt->size();
- optROData = alignPointer(optROData);
- optRORemaining -= clsopt->size();
- size_t duplicateCount = clsopt->duplicateCount();
- uint32_t clsoptCapacity = clsopt->capacity;
- uint32_t clsoptOccupied = clsopt->occupied;
- clsopt->byteswap(E::little_endian);
- clsopt = nullptr;
-
- diag.verbose(" found % 6ld duplicate classes\n",
- duplicateCount);
- diag.verbose(" class table occupancy %u/%u (%u%%)\n",
- clsoptOccupied, clsoptCapacity,
- (unsigned)(clsoptOccupied/(double)clsoptCapacity*100));
-
-
- //
- // Sort method lists.
- //
- // This is SAFE: modified binaries are still usable as unsorted lists.
- // This must be done AFTER uniquing selectors.
- MethodListSorter<P> methodSorter;
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- methodSorter.optimize(&cacheAccessor, mh);
- }
-
- diag.verbose(" sorted % 6ld method lists\n", methodSorter.optimized());
-
-
- // Unique protocols and build protocol table.
-
- // This is SAFE: no protocol references are updated yet
- // This must be done AFTER updating method lists.
-
- ProtocolOptimizer<P> protocolOptimizer(diag, hinfoROOptimizer);
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- protocolOptimizer.addProtocols(&cacheAccessor, mh);
- }
-
- diag.verbose(" uniqued % 6ld protocols\n",
- protocolOptimizer.protocolCount());
-
- pint_t protocolClassVMAddr = (pint_t)P::getP(optPointerList->protocolClass);
- err = protocolOptimizer.writeProtocols(&cacheAccessor,
- optRWData, optRWRemaining,
- optROData, optRORemaining,
- aslrTracker, protocolClassVMAddr);
- if (err) {
- diag.warning("%s", err);
- return;
- }
-
- // Align the buffer again. The new protocols may have added an odd number of name characters
- optROData = alignPointer(optROData);
-
- // New protocol table which tracks loaded images.
- uint64_t protocoloptVMAddr = cacheAccessor.vmAddrForContent(optROData);
- objc_opt::objc_protocolopt2_t *protocolopt = new (optROData) objc_opt::objc_protocolopt2_t;
- err = protocolopt->write(protocoloptVMAddr, optRORemaining,
- protocolOptimizer.protocolNames(),
- protocolOptimizer.protocolsAndHeaders(), false);
- if (err) {
- diag.warning("%s", err);
- return;
- }
- optROData += protocolopt->size();
- optROData = alignPointer(optROData);
- optRORemaining -= protocolopt->size();
- uint32_t protocoloptCapacity = protocolopt->capacity;
- uint32_t protocoloptOccupied = protocolopt->occupied;
- protocolopt->byteswap(E::little_endian), protocolopt = NULL;
-
- diag.verbose(" protocol table occupancy %u/%u (%u%%)\n",
- protocoloptOccupied, protocoloptCapacity,
- (unsigned)(protocoloptOccupied/(double)protocoloptCapacity*100));
-
-
- // Redirect protocol references to the uniqued protocols.
-
- // This is SAFE: the new protocol objects are still usable as-is.
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- protocolOptimizer.updateReferences(&cacheAccessor, mh);
- }
-
- diag.verbose(" updated % 6ld protocol references\n", protocolOptimizer.protocolReferenceCount());
-
-
- //
- // Repair ivar offsets.
- //
- // This is SAFE: the runtime always validates ivar offsets at runtime.
- IvarOffsetOptimizer<P> ivarOffsetOptimizer;
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- ivarOffsetOptimizer.optimize(&cacheAccessor, mh);
- }
-
- diag.verbose(" updated % 6ld ivar offsets\n", ivarOffsetOptimizer.optimized());
-
-
- // Collect flags.
- uint32_t headerFlags = 0;
- if (forProduction) {
- headerFlags |= objc_opt::IsProduction;
- }
- if (noMissingWeakSuperclasses) {
- headerFlags |= objc_opt::NoMissingWeakSuperclasses;
- }
-
-
- // Success. Mark dylibs as optimized.
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- const macho_section<P>* imageInfoSection = mh->getSection("__DATA", "__objc_imageinfo");
- if (!imageInfoSection) {
- imageInfoSection = mh->getSection("__OBJC", "__image_info");
- }
- if (imageInfoSection) {
- objc_image_info<P>* info = (objc_image_info<P>*)cacheAccessor.contentForVMAddr(imageInfoSection->addr());
- info->setOptimizedByDyld();
- }
- }
-
-
- // Success. Update __objc_opt_ro section in libobjc.dylib to contain offsets to generated optimization structures
- objc_opt::objc_opt_t* libROHeader = (objc_opt::objc_opt_t *)cacheAccessor.contentForVMAddr(optROSection->addr());
- E::set32(libROHeader->flags, headerFlags);
- E::set32(libROHeader->selopt_offset, (uint32_t)(seloptVMAddr - optROSection->addr()));
- E::set32(libROHeader->clsopt_offset, (uint32_t)(clsoptVMAddr - optROSection->addr()));
- E::set32(libROHeader->unused_protocolopt_offset, 0);
- E::set32(libROHeader->headeropt_ro_offset, (uint32_t)(hinfoROVMAddr - optROSection->addr()));
- E::set32(libROHeader->headeropt_rw_offset, (uint32_t)(hinfoRWVMAddr - optROSection->addr()));
- E::set32(libROHeader->protocolopt_offset, (uint32_t)(protocoloptVMAddr - optROSection->addr()));
-
- // Log statistics.
- size_t roSize = objcReadOnlyBufferSizeAllocated - optRORemaining;
- size_t rwSize = objcReadWriteBufferSizeAllocated - optRWRemaining;
- diag.verbose(" %lu/%llu bytes (%d%%) used in shared cache read-only optimization region\n",
- roSize, objcReadOnlyBufferSizeAllocated, percent(roSize, objcReadOnlyBufferSizeAllocated));
- diag.verbose(" %lu/%llu bytes (%d%%) used in shared cache read/write optimization region\n",
- rwSize, objcReadWriteBufferSizeAllocated, percent(rwSize, objcReadWriteBufferSizeAllocated));
- diag.verbose(" wrote objc metadata optimization version %d\n", objc_opt::VERSION);
-
- // Add segments to libobjc.dylib that cover cache builder allocated r/o and r/w regions
- addObjcSegments<P>(diag, cache, libobjcMH, objcReadOnlyBuffer, objcReadOnlyBufferSizeAllocated, objcReadWriteBuffer, objcReadWriteBufferSizeAllocated, objcRwFileOffset);
-
-
- // Now that objc has uniqued the selector references, we can apply the LOHs so that ADRP/LDR -> ADRP/ADD
- if (forProduction) {
- const bool logSelectors = false;
- uint64_t lohADRPCount = 0;
- uint64_t lohLDRCount = 0;
-
- for (auto& targetAndInstructions : lohTracker) {
- uint64_t targetVMAddr = targetAndInstructions.first;
- if (!selOptimizer.isSelectorRefAddress((pint_t)targetVMAddr))
- continue;
-
- std::set<void*>& instructions = targetAndInstructions.second;
- // We do 2 passes over the instructions. The first to validate them and the second
- // to actually update them.
- for (unsigned pass = 0; pass != 2; ++pass) {
- uint32_t adrpCount = 0;
- uint32_t ldrCount = 0;
- for (void* instructionAddress : instructions) {
- uint32_t& instruction = *(uint32_t*)instructionAddress;
- uint64_t instructionVMAddr = cacheAccessor.vmAddrForContent(&instruction);
- uint64_t selRefContent = *(uint64_t*)cacheAccessor.contentForVMAddr(targetVMAddr);
- const char* selectorString = (const char*)cacheAccessor.contentForVMAddr(selRefContent);
- uint64_t selectorStringVMAddr = cacheAccessor.vmAddrForContent(selectorString);
-
- if ( (instruction & 0x9F000000) == 0x90000000 ) {
- // ADRP
- int64_t pageDistance = ((selectorStringVMAddr & ~0xFFF) - (instructionVMAddr & ~0xFFF));
- int64_t newPage21 = pageDistance >> 12;
-
- if (pass == 0) {
- if ( (newPage21 > 2097151) || (newPage21 < -2097151) ) {
- if (logSelectors)
- fprintf(stderr, "Out of bounds ADRP selector reference target\n");
- instructions.clear();
- break;
- }
- ++adrpCount;
- }
-
- if (pass == 1) {
- instruction = (instruction & 0x9F00001F) | ((newPage21 << 29) & 0x60000000) | ((newPage21 << 3) & 0x00FFFFE0);
- ++lohADRPCount;
- }
- continue;
- }
-
- if ( (instruction & 0x3B000000) == 0x39000000 ) {
- // LDR/STR. STR shouldn't be possible as this is a selref!
- if (pass == 0) {
- if ( (instruction & 0xC0C00000) != 0xC0400000 ) {
- // Not a load, or dest reg isn't xN, or uses sign extension
- if (logSelectors)
- fprintf(stderr, "Bad LDR for selector reference optimisation\n");
- instructions.clear();
- break;
- }
- if ( (instruction & 0x04000000) != 0 ) {
- // Loading a float
- if (logSelectors)
- fprintf(stderr, "Bad LDR for selector reference optimisation\n");
- instructions.clear();
- break;
- }
- ++ldrCount;
- }
-
- if (pass == 1) {
- uint32_t ldrDestReg = (instruction & 0x1F);
- uint32_t ldrBaseReg = ((instruction >> 5) & 0x1F);
-
- // Convert the LDR to an ADD
- instruction = 0x91000000;
- instruction |= ldrDestReg;
- instruction |= ldrBaseReg << 5;
- instruction |= (selectorStringVMAddr & 0xFFF) << 10;
-
- ++lohLDRCount;
- }
- continue;
- }
-
- if ( (instruction & 0xFFC00000) == 0x91000000 ) {
- // ADD imm12
- // We don't support ADDs.
- if (logSelectors)
- fprintf(stderr, "Bad ADD for selector reference optimisation\n");
- instructions.clear();
- break;
- }
-
- if (logSelectors)
- fprintf(stderr, "Unknown instruction for selref optimisation\n");
- instructions.clear();
- break;
- }
- if (pass == 0) {
- // If we didn't see at least one ADRP/LDR in pass one then don't optimize this location
- if ((adrpCount == 0) || (ldrCount == 0)) {
- instructions.clear();
- break;
- }
- }
- }
- }
-
- diag.verbose(" Optimized %lld ADRP LOHs\n", lohADRPCount);
- diag.verbose(" Optimized %lld LDR LOHs\n", lohLDRCount);
- }
-}
-
-
-} // anon namespace
-
-void SharedCacheBuilder::optimizeObjC()
-{
- uint32_t objcRwFileOffset = (uint32_t)((_objcReadWriteBuffer - _readWriteRegion.buffer) + _readWriteRegion.cacheFileOffset);
- if ( _archLayout->is64 )
- doOptimizeObjC<Pointer64<LittleEndian>>((DyldSharedCache*)_readExecuteRegion.buffer, _options.optimizeStubs, _aslrTracker, _lohTracker,
- _coalescedText, _missingWeakImports,
- _diagnostics, _objcReadOnlyBuffer, _objcReadOnlyBufferSizeUsed, _objcReadOnlyBufferSizeAllocated,
- _objcReadWriteBuffer, _objcReadWriteBufferSizeAllocated, objcRwFileOffset);
- else
- doOptimizeObjC<Pointer32<LittleEndian>>((DyldSharedCache*)_readExecuteRegion.buffer, _options.optimizeStubs, _aslrTracker, _lohTracker,
- _coalescedText, _missingWeakImports,
- _diagnostics, _objcReadOnlyBuffer, _objcReadOnlyBufferSizeUsed, _objcReadOnlyBufferSizeAllocated,
- _objcReadWriteBuffer, _objcReadWriteBufferSizeAllocated, objcRwFileOffset);
-}
-
-static uint32_t hashTableSize(uint32_t maxElements, uint32_t perElementData)
-{
- uint32_t elementsWithPadding = maxElements*11/10; // if close to power of 2, perfect hash may fail, so don't get within 10% of that
- uint32_t powTwoCapacity = 1 << (32 - __builtin_clz(elementsWithPadding - 1));
- uint32_t headerSize = 4*(8+256);
- return headerSize + powTwoCapacity/2 + powTwoCapacity + powTwoCapacity*perElementData;
-}
-
-// The goal here is to allocate space in the dyld shared cache (while it is being laid out) that will contain
-// the objc structures that previously were in the __objc_opt_ro section.
-uint32_t SharedCacheBuilder::computeReadOnlyObjC(uint32_t selRefCount, uint32_t classDefCount, uint32_t protocolDefCount)
-{
- return 0xA000 + hashTableSize(selRefCount, 5) + hashTableSize(classDefCount, 12) + hashTableSize(protocolDefCount, 8);
-}
-
-// Space to replace the __objc_opt_rw section.
-uint32_t SharedCacheBuilder::computeReadWriteObjC(uint32_t imageCount, uint32_t protocolDefCount)
-{
- return 8*imageCount + protocolDefCount*12*(_archLayout->is64 ? 8 : 4);
-}