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--- dyld/dyld-960/cache-builder/OptimizerObjC.cpp
+++ /dev/null
@@ -1,1837 +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 "IMPCachesBuilder.hpp"
-#include "SharedCacheBuilder.h"
-#include "FileAbstraction.hpp"
-#include "MachOFileAbstraction.hpp"
-#include "MachOLoaded.h"
-#include "MachOAnalyzer.h"
-#include "PerfectHash.h"
-#include "OptimizerObjC.h"
-#include "objc-shared-cache.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;
-};
-
-// Note these must be after the ContentAccessor, PointerSection and ArraySection definitions
-#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::string_map::iterator element =
- _selectorStrings.insert(objc::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::string_map& strings() {
- return _selectorStrings;
- }
-
- size_t count() const { return _count; }
-
-private:
- objc::string_map _selectorStrings;
- ContentAccessor* _cache;
- size_t _count = 0;
-};
-
-
-template <typename P>
-class ClassListBuilder
-{
-private:
- std::unordered_map<std::string_view, uint64_t> _uniquedClassNames;
- objc::string_map _classNames;
- objc::class_map _classes;
- size_t _count = 0;
- const std::unordered_map<const macho_header<P>*, uint16_t>& _dylibIndices;
-
-public:
-
- ClassListBuilder(const std::unordered_map<const macho_header<P>*, uint16_t>& dylibIndices) : _dylibIndices(dylibIndices) { }
-
- void visitCoalescedStrings(const CacheBuilder::CacheCoalescedText& coalescedText) {
- const CacheBuilder::CacheCoalescedText::StringSection& classNames = coalescedText.getSectionData("__objc_classname");
- for (const auto& stringAndOffset : classNames.stringsToOffsets) {
- uint64_t vmAddr = classNames.bufferVMAddr + stringAndOffset.second;
- _uniquedClassNames[stringAndOffset.first.data()] = vmAddr;
- }
- }
-
- 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);
- // Check for an overide of the name vmAddr. This happens with split caches when we need to copy the names to be
- // within 32-bits of the hash table
- if ( auto it = _uniquedClassNames.find(name); it != _uniquedClassNames.end() )
- name_vmaddr = it->second;
- uint64_t cls_vmaddr = cache->vmAddrForContent(cls);
- auto dylibIndexIt = _dylibIndices.find(header);
- assert(dylibIndexIt != _dylibIndices.end());
- _classNames.insert(objc::string_map::value_type(name, name_vmaddr));
- _classes.insert(objc::class_map::value_type(name, std::pair<uint64_t, uint64_t>(cls_vmaddr, dylibIndexIt->second)));
- _count++;
- }
-
- objc::string_map& classNames() {
- return _classNames;
- }
-
- objc::class_map& classes() {
- return _classes;
- }
-
- size_t count() const { return _count; }
-};
-
-
-/// Builds a map from (install name, class name, method name) to actual IMPs
-template <typename P>
-class IMPMapBuilder
-{
-private:
- typedef typename P::uint_t pint_t;
-
-public:
-
- struct MapKey {
- std::string_view installName;
- std::string_view className;
- std::string_view methodName;
- bool isInstanceMethod;
-
- bool operator==(const MapKey& other) const {
- return isInstanceMethod == other.isInstanceMethod &&
- installName == other.installName &&
- className == other.className &&
- methodName == other.methodName;
- }
-
- size_t hash() const {
- std::size_t seed = 0;
- seed ^= std::hash<std::string_view>()(installName) + 0x9e3779b9 + (seed<<6) + (seed>>2);
- seed ^= std::hash<std::string_view>()(className) + 0x9e3779b9 + (seed<<6) + (seed>>2);
- seed ^= std::hash<std::string_view>()(methodName) + 0x9e3779b9 + (seed<<6) + (seed>>2);
- seed ^= std::hash<bool>()(isInstanceMethod) + 0x9e3779b9 + (seed<<6) + (seed>>2);
- return seed;
- }
- };
-
- struct MapKeyHasher {
- size_t operator()(const MapKey& k) const {
- return k.hash();
- }
- };
-
- std::unordered_map<MapKey, pint_t, MapKeyHasher> impMap;
- std::optional<uint64_t> relativeMethodListBaseAddress;
-
- IMPMapBuilder(std::optional<uint64_t> relativeMethodListBaseAddress)
- : relativeMethodListBaseAddress(relativeMethodListBaseAddress) { }
-
- void visitClass(ContentAccessor* cache,
- const macho_header<P>* header,
- objc_class_t<P>* cls)
- {
- objc_method_list_t<P> *methodList = cls->getMethodList(cache);
- if (methodList == nullptr) return;
-
- const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)header;
- bool isInstanceMethod = !cls->isMetaClass(cache);
- const char* className = cls->getName(cache);
- const char* installName = ma->installName();
-
- for (uint32_t n = 0; n < methodList->getCount(); n++) {
- // do not clobber an existing entry if any, because categories win
- impMap.try_emplace(MapKey{
- .installName = installName,
- .className = className,
- .methodName = methodList->getStringName(cache, n, relativeMethodListBaseAddress),
- .isInstanceMethod = isInstanceMethod
- }, methodList->getImp(n, cache));
- }
- }
-
- void visit(ContentAccessor* cache, const macho_header<P>* header) {
- const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)header;
-
- // Method lists from categories
- PointerSection<P, objc_category_t<P> *>
- cats(cache, header, "__DATA", "__objc_catlist");
- for (pint_t i = 0; i < cats.count(); i++) {
- objc_category_t<P> *cat = cats.get(i);
- objc_class_t<P>* cls = cat->getClass(cache);
- if (cls == nullptr)
- continue;
-
- objc_method_list_t<P> *instanceMethods = cat->getInstanceMethods(cache);
- if (instanceMethods != nullptr) {
- for (uint32_t n = 0; n < instanceMethods->getCount(); n++) {
- MapKey k {
- .installName = ma->installName(),
- .className = cls->getName(cache),
- .methodName = instanceMethods->getStringName(cache, n, relativeMethodListBaseAddress),
- .isInstanceMethod = true
- };
- //printf("Adding %s %s %s %d cat %s\n", k.installName.data(), k.className.data(), k.methodName.data(), k.isInstanceMethod, k.catName->data());
- impMap[k] = instanceMethods->getImp(n, cache);
- }
- }
- objc_method_list_t<P> *classMethods = cat->getClassMethods(cache);
- if (classMethods != nullptr) {
- for (uint32_t n = 0; n < classMethods->getCount(); n++) {
- MapKey k {
- .installName = ma->installName(),
- .className = cls->getName(cache),
- .methodName = classMethods->getStringName(cache, n, relativeMethodListBaseAddress),
- .isInstanceMethod = false
- };
- //printf("Adding %s %s %s %d cat %s\n", k.installName.data(), k.className.data(), k.methodName.data(), k.isInstanceMethod, k.catName->data());
- impMap[k] = classMethods->getImp(n, cache);
- }
- }
- }
- }
-};
-
-// List of offsets in libobjc that the shared cache optimization needs to use.
-template <typename T>
-struct objc_opt_imp_caches_pointerlist_tt {
- T selectorStringVMAddrStart;
- T selectorStringVMAddrEnd;
- T inlinedSelectorsVMAddrStart;
- T inlinedSelectorsVMAddrEnd;
-};
-
-template <typename P>
-class IMPCachesEmitter
-{
- typedef typename P::uint_t pint_t;
-
-private:
- Diagnostics& diag;
- const IMPMapBuilder<P>& impMapBuilder;
- uint64_t selectorStringVMAddr;
- uint8_t*& readOnlyBuffer;
- size_t& readOnlyBufferSize;
- uint8_t*& readWriteBuffer;
- size_t& readWriteBufferSize;
- int cachesFormatVersion;
-
- // This tracks the slide info for anything in __OBJC_RW, but other dylibs may
- // use other trackers
- CacheBuilder::ASLR_Tracker& objcASLRTracker;
-
- std::map<std::string_view, const SharedCacheBuilder::DylibInfo*> _dylibInfos;
- std::map<std::string_view, const macho_header<P>*> _dylibs;
- const std::vector<const IMPCaches::Selector*> inlinedSelectors;
-
- struct ImpCacheHeader {
- int32_t fallback_class_offset;
- uint32_t cache_shift : 5;
- uint32_t cache_mask : 11;
- uint32_t occupied : 14;
- uint32_t has_inlines : 1;
- uint32_t bit_one : 1;
- };
-
- struct ImpCacheEntry_v1 {
- uint32_t selOffset;
- uint32_t impOffset;
- };
-
- struct ImpCacheEntry_v2 {
- int64_t impOffset : 38;
- uint64_t selOffset : 26;
- };
-
-public:
-
- static size_t sizeForImpCacheWithCount(int entries) {
- static_assert(sizeof(ImpCacheEntry_v1) == sizeof(ImpCacheEntry_v2));
- return sizeof(ImpCacheHeader) + entries * sizeof(ImpCacheEntry_v1);
- }
-
- struct ImpCacheContents {
- struct bucket_t {
- uint32_t sel_offset = 0;
- uint64_t imp = 0;
- };
- std::vector<bucket_t> buckets;
- uint64_t occupiedBuckets = 0;
- bool hasInlines = false;
-
- uint64_t capacity() const
- {
- return buckets.size();
- }
-
- uint64_t occupied() const {
- return occupiedBuckets;
- }
-
- void incrementOccupied() {
- ++occupiedBuckets;
- }
-
- void insert(uint64_t slot, uint64_t selOffset, uint64_t imp) {
- bucket_t& b = buckets[slot];
- assert(b.imp == 0);
-
- if (!b.imp) incrementOccupied();
- assert((uint32_t)selOffset == selOffset);
- b.sel_offset = (uint32_t)selOffset;
- b.imp = imp;
- }
-
- void fillBuckets(const IMPCaches::ClassData* classData, bool metaclass, const IMPMapBuilder<P> & classRecorder) {
- const std::vector<IMPCaches::ClassData::Method> & methods = classData->methods;
- buckets.resize(classData->modulo());
- for (const IMPCaches::ClassData::Method& method : methods) {
- typename IMPMapBuilder<P>::MapKey k {
- .installName = method.installName,
- .className = method.className,
- .methodName = method.selector->name,
- .isInstanceMethod = !metaclass
- };
-
- pint_t imp = classRecorder.impMap.at(k);
- int slot = (method.selector->inProgressBucketIndex >> classData->shift) & classData->mask();
- insert(slot, method.selector->offset, imp);
- hasInlines |= (method.wasInlined && !method.fromFlattening);
- }
- }
-
- std::pair<uint64_t, uint64_t>
- write(ContentAccessor* cache,
- uint64_t cacheSelectorStringVMAddr, uint64_t clsVMAddr,
- uint8_t*& buf, size_t& bufSize, int version, Diagnostics& diags) {
- constexpr bool log = false;
- static_assert(sizeof(ImpCacheEntry_v1) == sizeof(ImpCacheEntry_v2));
- uint64_t spaceRequired = sizeof(ImpCacheEntry_v1) * capacity();
-
- if (spaceRequired > bufSize) {
- diags.error("Not enough space for imp cache");
- return { 0, 0 };
- }
-
- // Convert from addresses to offsets and write out
- const void *offsetBucketsLocation = buf;
- if (version == 1) {
- ImpCacheEntry_v1* offsetBuckets = (ImpCacheEntry_v1*)buf;
- // printf("Buckets: 0x%08llx\n", cache->vmAddrForContent(offsetBuckets));
- for (uint64_t index = 0; index != buckets.size(); ++index) {
- bucket_t bucket = buckets[index];
- if (bucket.sel_offset == 0 && bucket.imp == 0) {
- // Empty bucket
- offsetBuckets[index].selOffset = 0xFFFFFFFF;
- offsetBuckets[index].impOffset = 0;
- } else {
- int64_t selOffset = (int64_t)bucket.sel_offset;
- int64_t impOffset = clsVMAddr - bucket.imp;
- assert((int32_t)impOffset == impOffset);
- assert((int32_t)selOffset == selOffset);
- offsetBuckets[index].selOffset = (int32_t)selOffset;
- offsetBuckets[index].impOffset = (int32_t)impOffset;
- if (log) {
- diags.verbose("[IMP Caches] Coder[%lld]: %#08llx (sel: %#08x, imp %#08x) %s\n", index,
- cache->vmAddrForOnDiskVMAddr(bucket.imp),
- (int32_t)selOffset, (int32_t)impOffset,
- (const char*)cache->contentForVMAddr(cacheSelectorStringVMAddr + bucket.sel_offset));
- }
- }
- }
- } else {
- ImpCacheEntry_v2* offsetBuckets = (ImpCacheEntry_v2*)buf;
- // printf("Buckets: 0x%08llx\n", cache->vmAddrForContent(offsetBuckets));
- for (uint64_t index = 0; index != buckets.size(); ++index) {
- bucket_t bucket = buckets[index];
- if (bucket.sel_offset == 0 && bucket.imp == 0) {
- // Empty bucket
- offsetBuckets[index].selOffset = 0x3FFFFFF;
- offsetBuckets[index].impOffset = 0;
- } else {
- int64_t selOffset = (int64_t)bucket.sel_offset;
- int64_t impOffset = clsVMAddr - bucket.imp;
-
- assert(impOffset % 4 == 0); // dest and source should be aligned
- impOffset >>= 2;
- // objc assumes the imp offset always has
- // its two bottom bits set to 0, this lets us have
- // 4x more reach
-
- assert(impOffset < 1ll << 39);
- assert(-impOffset < 1ll << 39);
- assert(selOffset < 0x4000000);
- offsetBuckets[index].selOffset = selOffset;
- offsetBuckets[index].impOffset = impOffset;
- if (log) {
- diags.verbose("[IMP Caches] Coder[%lld]: %#08llx (sel: %#08llx, imp %#08llx) %s\n", index,
- cache->vmAddrForOnDiskVMAddr(bucket.imp),
- selOffset, impOffset,
- (const char*)cache->contentForVMAddr(cacheSelectorStringVMAddr + bucket.sel_offset));
- }
- }
- }
- }
-
- buf += spaceRequired;
- bufSize -= spaceRequired;
-
- return { cache->vmAddrForContent(offsetBucketsLocation), (uint64_t)buckets.size() };
- }
- };
-
- IMPCachesEmitter(Diagnostics& diags, const IMPMapBuilder<P>& builder, uint64_t selectorStringVMAddr, uint8_t*& roBuf, size_t& roBufSize, uint8_t* &rwBuf, size_t& rwBufSize, const std::vector<SharedCacheBuilder::DylibInfo> & dylibInfos, const std::vector<const macho_header<P>*> & dylibs, CacheBuilder::ASLR_Tracker& objcASLRTracker, int cachesVersion)
- : diag(diags), impMapBuilder(builder), selectorStringVMAddr(selectorStringVMAddr), readOnlyBuffer(roBuf), readOnlyBufferSize(roBufSize), readWriteBuffer(rwBuf), readWriteBufferSize(rwBufSize),
- cachesFormatVersion(cachesVersion), objcASLRTracker(objcASLRTracker) {
- for (const SharedCacheBuilder::DylibInfo& d : dylibInfos) {
- _dylibInfos[d.dylibID] = &d;
- }
- for (const macho_header<P>* d : dylibs) {
- const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*) d;
- _dylibs[ma->installName()] = d;
- }
- }
-
- // Returns true if we should filter this class out from getting an imp cache
- bool filter(ContentAccessor* cache, const dyld3::MachOAnalyzer* ma, const objc_class_t<P>* cls) {
- const SharedCacheBuilder::DylibInfo* d = _dylibInfos[ma->installName()];
- IMPCaches::ClassKey key {
- .name = cls->getName(cache),
- .metaclass = cls->isMetaClass(cache)
- };
- return (d->impCachesClassData.find(key) == d->impCachesClassData.end());
- }
-
- void visitClass(ContentAccessor* cache,
- const macho_header<P>* header,
- objc_class_t<P>* cls)
- {
- // If we ran out of space then don't try to optimize more
- if (diag.hasError())
- return;
-
- const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*) header;
- if (filter(cache, ma, cls)) {
- *cls->getVTableAddress() = 0;
- return;
- }
-
- const char* className = cls->getName(cache);
-
- if (cls->getVTable(cache) != 0) {
- diag.error("Class (%s) has non-zero vtable\n", className);
- return;
- }
-
- const SharedCacheBuilder::DylibInfo* d = _dylibInfos[ma->installName()];
- IMPCaches::ClassKey key {
- .name = cls->getName(cache),
- .metaclass = cls->isMetaClass(cache)
- };
- IMPCaches::ClassData* data = (d->impCachesClassData.at(key)).get();
-#if 0
- for (const objc_method_t<P>& method : methods) {
- printf(" 0x%llx: 0x%llx (%s)\n", method.getImp(), method.getName(),
- (const char*)cache->contentForVMAddr(method.getName()));
- }
-#endif
-
- uint64_t clsVMAddr = cache->vmAddrForContent(cls);
-
- if (data->mask() > 0x7ff) {
- diag.verbose("Cache for class %s (%#08llx) is too large (mask: %#x)\n",
- className, clsVMAddr, data->mask());
- return;
- }
-
- ImpCacheContents impCache;
- impCache.fillBuckets(data, cls->isMetaClass(cache), impMapBuilder);
-
- constexpr bool log = false;
- if (log) {
- printf("Writing cache for %sclass %s (%#08llx)\n", cls->isMetaClass(cache) ? "meta" : "", className, clsVMAddr);
- }
-
- struct ImpCacheHeader {
- int32_t fallback_class_offset;
- uint32_t cache_shift : 5;
- uint32_t cache_mask : 11;
- uint32_t occupied : 14;
- uint32_t has_inlines : 1;
- uint32_t bit_one : 1;
- };
- pint_t* vtableAddr = cls->getVTableAddress();
-
- // the alignment of ImpCaches to 16 bytes is only needed for arm64_32.
- ImpCacheHeader* cachePtr = (ImpCacheHeader*)align_buffer(readOnlyBuffer, sizeof(pint_t) == 4 ? 4 : 3);
-
- assert(readOnlyBufferSize > sizeof(ImpCacheHeader));
-
- uint64_t occupied = impCache.occupied();
- int64_t fallback_class_offset = *(cls->getSuperClassAddress()) - clsVMAddr;
-
- if (data->flatteningRootSuperclass) {
- // If we are a class being flattened (inheriting all the selectors of
- // its superclasses up to and including the flattening root), the fallback class
- // should be the first superclass which is not flattened.
-
- // Find the VMAddr of that superclass, given its segment index and offset
- // in the source dylib.
- const auto & superclass = *(data->flatteningRootSuperclass);
- const dyld3::MachOAnalyzer* superMA = (const dyld3::MachOAnalyzer*)_dylibs[superclass.installName];
- __block uint64_t superclassVMAddr = 0;
- superMA->forEachSegment(^(const dyld3::MachOAnalyzer::SegmentInfo &info, bool &stop) {
- if (info.segIndex == superclass.segmentIndex) {
- superclassVMAddr = info.vmAddr + superclass.segmentOffset;
- stop = true;
- }
- });
-
- assert(superclassVMAddr > 0);
- fallback_class_offset = superclassVMAddr - clsVMAddr;
- }
-
- assert((int32_t)fallback_class_offset == fallback_class_offset);
- assert((uint32_t)occupied == occupied);
-
- *cachePtr = (ImpCacheHeader){
- .fallback_class_offset = (int32_t)fallback_class_offset,
- .cache_shift = (uint32_t)(data->shift + 7),
- .cache_mask = (uint32_t)data->mask(),
- .occupied = (uint32_t)occupied,
- .has_inlines = impCache.hasInlines,
- .bit_one = 1, // obj-c plays HORRENDOUS games here
- };
-
- // is this right?
- int64_t vmaddr = cache->vmAddrForContent(readOnlyBuffer);
- assert((pint_t)vmaddr == (uint64_t)vmaddr);
- *vtableAddr = (pint_t)cache->vmAddrForContent(readOnlyBuffer);
- d->_aslrTracker->add(vtableAddr);
- readOnlyBuffer += sizeof(ImpCacheHeader);
- readOnlyBufferSize -= sizeof(ImpCacheHeader);
-
- impCache.write(cache, selectorStringVMAddr, clsVMAddr, readOnlyBuffer, readOnlyBufferSize, cachesFormatVersion, diag);
- }
-
- void emitInlinedSelectors(const std::vector<const IMPCaches::Selector*> selectors) {
- // FIXME: this should be in constant memory
- for (const IMPCaches::Selector* s : selectors) {
- assert(readWriteBufferSize >= sizeof(pint_t));
- *(pint_t*)readWriteBuffer = (pint_t)(selectorStringVMAddr + s->offset);
- objcASLRTracker.add(readWriteBuffer);
- readWriteBuffer += sizeof(pint_t);
- readWriteBufferSize -= sizeof(pint_t);
- }
- }
-};
-
-template <typename P>
-class ProtocolOptimizer
-{
-private:
- typedef typename P::uint_t pint_t;
-
- std::unordered_map<std::string_view, uint64_t> _uniquedProtocolNames;
- objc::string_map _protocolNames;
- objc::legacy_protocol_map _protocols;
- objc::protocol_map _protocolsAndHeaders;
- size_t _protocolCount;
- size_t _protocolReferenceCount;
- Diagnostics& _diagnostics;
- const std::unordered_map<const macho_header<P>*, uint16_t>& _dylibIndices;
-
- 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, const std::unordered_map<const macho_header<P>*, uint16_t>& dylibIndices)
- : _protocolCount(0), _protocolReferenceCount(0), _diagnostics(diag), _dylibIndices(dylibIndices) {
- }
-
- void visitCoalescedStrings(const CacheBuilder::CacheCoalescedText& coalescedText) {
- const CacheBuilder::CacheCoalescedText::StringSection& classNames = coalescedText.getSectionData("__objc_classname");
- for (const auto& stringAndOffset : classNames.stringsToOffsets) {
- uint64_t vmAddr = classNames.bufferVMAddr + stringAndOffset.second;
- _uniquedProtocolNames[stringAndOffset.first.data()] = vmAddr;
- }
- }
-
- 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);
- // Check for an overide of the name vmAddr. This happens with split caches when we need to copy the names to be
- // within 32-bits of the hash table
- if ( auto it = _uniquedProtocolNames.find(name); it != _uniquedProtocolNames.end() )
- name_vmaddr = it->second;
- uint64_t proto_vmaddr = cache->vmAddrForContent(proto);
- _protocolNames.insert(objc::string_map::value_type(name, name_vmaddr));
- _protocols.insert(objc::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.
- auto dylibIndexIt = _dylibIndices.find(header);
- assert(dylibIndexIt != _dylibIndices.end());
- _protocolsAndHeaders.insert(objc::class_map::value_type(name, std::pair<uint64_t, uint64_t>(0, dylibIndexIt->second)));
- }
- }
-
- const char *writeProtocols(ContentAccessor* cache,
- uint8_t *& rwdest, size_t& rwremaining,
- uint8_t *& rodest, size_t& roremaining,
- CacheBuilder::ASLR_Tracker& aslrTracker,
- pint_t protocolClassVMAddr,
- const dyld3::MachOLoaded::PointerMetaData& PMD)
- {
- 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 the objc runtime signed the Protocol ISA, then we need to too
- if ( PMD.authenticated ) {
- aslrTracker.setAuthData(proto->getISALocation(), PMD.diversity, PMD.usesAddrDiversity, PMD.key);
- }
-
- 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::string_map& protocolNames() {
- return _protocolNames;
- }
-
- objc::legacy_protocol_map& protocols() {
- return _protocols;
- }
-
- objc::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,
- uint64_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
- // TODO: Work out if we need this when not using sub caches. Right now we always copy
- // install names to the cache header, so we never need this code.
- // Depends on whether we always copy install names in to the cache header
-#if 0
- if ( cache->header.subCacheUUIDsCount == 0 ) {
- 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;
- }
- }
- }
-#endif
-}
-
-template <typename P> static inline void emitIMPCaches(ContentAccessor& cacheAccessor,
- std::vector<SharedCacheBuilder::DylibInfo> & allDylibs,
- std::vector<const macho_header<P>*> & sizeSortedDylibs,
- std::optional<uint64_t> relativeMethodListBaseAddress,
- uint64_t selectorStringVMAddr,
- uint8_t* optROData, size_t& optRORemaining,
- uint8_t* optRWData, size_t& optRWRemaining,
- CacheBuilder::ASLR_Tracker& objcASLRTracker,
- const std::vector<const IMPCaches::Selector*> & inlinedSelectors,
- uint8_t* &inlinedSelectorsStart,
- uint8_t* &inlinedSelectorsEnd,
- int impCachesVersion,
- Diagnostics& diag,
- TimeRecorder& timeRecorder) {
- diag.verbose("[IMP caches] computing IMP map\n");
-
- IMPMapBuilder<P> classRecorder(relativeMethodListBaseAddress);
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- ClassWalker<P, IMPMapBuilder<P>> classWalker(classRecorder, ClassWalkerMode::ClassAndMetaclasses);
- classWalker.walk(&cacheAccessor, mh);
- classRecorder.visit(&cacheAccessor, mh);
- }
-
- timeRecorder.recordTime("compute IMP map");
- diag.verbose("[IMP caches] emitting IMP caches\n");
-
- IMPCachesEmitter<P> impCachesEmitter(diag, classRecorder, selectorStringVMAddr, optROData, optRORemaining, optRWData, optRWRemaining, allDylibs, sizeSortedDylibs, objcASLRTracker, impCachesVersion);
- ClassWalker<P, IMPCachesEmitter<P>> impEmitterClassWalker(impCachesEmitter, ClassWalkerMode::ClassAndMetaclasses);
- for (const macho_header<P>* mh : sizeSortedDylibs) {
- impEmitterClassWalker.walk(&cacheAccessor, mh);
- if (diag.hasError())
- return;
- }
-
- inlinedSelectorsStart = optRWData;
- impCachesEmitter.emitInlinedSelectors(inlinedSelectors);
- inlinedSelectorsEnd = optRWData;
-}
-
-template <typename P>
-void doOptimizeObjC(DyldSharedCache* cache, bool forProduction,
- 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,
- uint64_t objcRwFileOffset,
- std::vector<SharedCacheBuilder::DylibInfo> & allDylibs,
- const std::vector<const IMPCaches::Selector*> & inlinedSelectors,
- bool impCachesSuccess,
- TimeRecorder& timeRecorder)
-{
- 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.error("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 const macho_section<P> *optImpCachesPointerSection = nullptr;
- __block std::vector<const macho_header<P>*> objcDylibs;
- __block std::unordered_map<const macho_header<P>*, uint16_t> dylibIndices;
- 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 ( optPointerListSection == nullptr )
- optPointerListSection = mh->getSection("__AUTH", "__objc_opt_ptrs");
- optImpCachesPointerSection = mh->getSection("__DATA_CONST", "__objc_scoffs");
- }
- if ( mh->getSection("__DATA", "__objc_imageinfo") || mh->getSection("__OBJC", "__image_info") ) {
- objcDylibs.push_back(mh);
- dylibIndices[mh] = (uint16_t)dylibIndices.size();
- } else {
- // Swift assumes all protocol conformance images also have an objc HeaderInfoRW to check for being loaded
- // Note, an improvement here, which would stop dyld needing to parse HeaderInfo, is to have a shared cache
- // state which we can access at runtime. We do have the PBLS state today in dyld4, but its not used with
- // JIT loaders.
- const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)mh;
- auto vmAddrConverter = ma->makeVMAddrConverter(false);
- Diagnostics diags;
- __block bool hasSwiftProtocols = false;
- ma->forEachSwiftProtocolConformance(diags, vmAddrConverter, true,
- ^(uint64_t protocolConformanceRuntimeOffset,
- const dyld3::MachOAnalyzer::SwiftProtocolConformance& protocolConformance,
- bool& stopProtocolConformance) {
- hasSwiftProtocols = true;
- stopProtocolConformance = true;
- });
- if ( hasSwiftProtocols ) {
- diag.error("All Swift protocol conformances dylibs are required to have __objc_imageinfo sections");
- }
- }
- // log("installName %s at mhdr 0x%016lx", installName, (uintptr_t)cacheAccessor.vmAddrForContent((void*)mh));
- });
- if ( diag.hasError() )
- return;
- if ( optROSection == nullptr ) {
- diag.error("libobjc's read-only section missing (metadata not optimized)");
- return;
- }
- if ( optPointerListSection == nullptr ) {
- diag.error("libobjc's pointer list section missing (metadata not optimized)");
- return;
- }
- if ( optImpCachesPointerSection == nullptr ) {
- diag.warning("libobjc's magical IMP caches shared cache offsets list section missing (metadata not optimized)");
- }
-
- // Split caches might move __OBJC_RO and __OBJC_RW far away from each other, and from libobjc. Maybe sure they are within
- // the 32-bit offsets in the __objc_opt_ro section
- {
- uint64_t readOnlyVMAddr = cacheAccessor.vmAddrForContent(objcReadOnlyBuffer);
- int64_t readOnlyStartOffset = readOnlyVMAddr - optROSection->addr();
- if ( (int32_t)readOnlyStartOffset != readOnlyStartOffset ) {
- diag.error("__OBJC_RO is out of range");
- return;
- }
- int64_t readOnlyEndOffset = (readOnlyVMAddr + objcReadOnlyBufferSizeAllocated) - optROSection->addr();
- if ( (int32_t)readOnlyEndOffset != readOnlyEndOffset ) {
- diag.error("__OBJC_RO is out of range");
- return;
- }
-
- uint64_t readWriteVMAddr = cacheAccessor.vmAddrForContent(objcReadWriteBuffer);
- int64_t readWriteStartOffset = readWriteVMAddr - optROSection->addr();
- if ( (int32_t)readWriteStartOffset != readWriteStartOffset ) {
- diag.error("__OBJC_RW is out of range");
- return;
- }
- int64_t readWriteEndOffset = (readWriteVMAddr + objcReadWriteBufferSizeAllocated) - optROSection->addr();
- if ( (int32_t)readWriteEndOffset != readWriteEndOffset ) {
- diag.error("__OBJC_RW is out of range");
- 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.error("libobjc's read-only section has bad content");
- return;
- }
-
- uint8_t* optRWData = objcReadWriteBuffer;
- size_t optRWRemaining = objcReadWriteBufferSizeAllocated;
- if (optRORemaining < headerSize) {
- diag.error("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.error("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.error("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());
-
- // Find the ASLR Tracker for libobjc. That tracks the range for objcRW
- CacheBuilder::ASLR_Tracker* objcASLRTracker = nullptr;
- for (const SharedCacheBuilder::DylibInfo& dylibInfo : allDylibs) {
- if ( strstr(dylibInfo.input->mappedFile.mh->installName(), "/libobjc.") != nullptr ) {
- objcASLRTracker = dylibInfo._aslrTracker;
- break;
- }
- }
- if ( objcASLRTracker == nullptr ) {
- diag.error("libobjc's ASLR Tracker could not be found");
- return;
- }
-
- // 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.error("%s", err);
- return;
- }
- else {
- for (const macho_header<P>* mh : addressSortedDylibs) {
- hinfoROOptimizer.update(&cacheAccessor, mh);
- }
- }
-
- // 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.error("%s", err);
- return;
- }
- else {
- for (const macho_header<P>* mh : addressSortedDylibs) {
- hinfoRWOptimizer.update(&cacheAccessor, mh);
- }
- }
-
- //
- // 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);
- };
-
- // Relative method lists names are initially an offset to a selector reference.
- // Eventually we'll update them to offsets directly to the selector string, from the given base address
-
- SelectorOptimizer<P, ObjCSelectorUniquer<P> > selOptimizer(uniq);
- selOptimizer.visitCoalescedStrings(coalescedText);
- uint64_t relativeMethodListBaseAddress = 0;
- constexpr std::string_view magicSelector = "\xf0\x9f\xa4\xaf";
- if ( auto it = selOptimizer.strings().find(magicSelector.data()); it != selOptimizer.strings().end() ) {
- relativeMethodListBaseAddress = it->second;
- selOptimizer.setSelectorBaseAddress(relativeMethodListBaseAddress);
- } else {
- diag.error("Could not find magic selector string address");
- return;
- }
- 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::SelectorHashTable *selopt = new(optROData) objc::SelectorHashTable;
- selopt->write(diag, seloptVMAddr, optRORemaining, uniq.strings());
- if ( diag.hasError() )
- return;
- optROData += selopt->size();
- optROData = alignPointer(optROData);
- optRORemaining -= selopt->size();
- }
-
-
- //
- // 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(dylibIndices);
- classes.visitCoalescedStrings(coalescedText);
- 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::ClassHashTable *clsopt = new(optROData) objc::ClassHashTable;
- clsopt->write(diag, clsoptVMAddr, cacheAccessor.vmAddrForContent(cache), optRORemaining,
- classes.classNames(), classes.classes());
- if ( diag.hasError() )
- return;
- optROData += clsopt->size();
- optROData = alignPointer(optROData);
- optRORemaining -= clsopt->size();
- }
-
-
- //
- // Sort method lists.
- //
- // This is SAFE: modified binaries are still usable as unsorted lists.
- // This must be done AFTER uniquing selectors.
- MethodListSorter<P> methodSorter(relativeMethodListBaseAddress);
- 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, dylibIndices);
- protocolOptimizer.visitCoalescedStrings(coalescedText);
- 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);
-
- // Get the pointer metadata from the magic protocolClassVMAddr symbol
- // We'll transfer it over to the ISA on all the objc protocols when we set their ISAs
- dyld3::MachOLoaded::PointerMetaData protocolClassPMD;
- uint16_t protocolClassAuthDiversity = 0;
- bool protocolClassAuthIsAddr = false;
- uint8_t protocolClassAuthKey = 0;
- if ( objcASLRTracker->hasAuthData((void*)&optPointerList->protocolClass, &protocolClassAuthDiversity, &protocolClassAuthIsAddr, &protocolClassAuthKey) ) {
- protocolClassPMD.diversity = protocolClassAuthDiversity;
- protocolClassPMD.high8 = 0;
- protocolClassPMD.authenticated = 1;
- protocolClassPMD.key = protocolClassAuthKey;
- protocolClassPMD.usesAddrDiversity = protocolClassAuthIsAddr;
- }
-
- err = protocolOptimizer.writeProtocols(&cacheAccessor,
- optRWData, optRWRemaining,
- optROData, optRORemaining,
- *objcASLRTracker, protocolClassVMAddr,
- protocolClassPMD);
- if (err) {
- diag.error("%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::ProtocolHashTable *protocolopt = new (optROData) objc::ProtocolHashTable;
- protocolopt->write(diag, protocoloptVMAddr, cacheAccessor.vmAddrForContent(cache), optRORemaining,
- protocolOptimizer.protocolNames(),
- protocolOptimizer.protocolsAndHeaders());
- if ( diag.hasError() )
- return;
- optROData += protocolopt->size();
- optROData = alignPointer(optROData);
- optRORemaining -= protocolopt->size();
- }
-
-
- // 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());
-
- //
- // Build imp caches
- //
- // Objc has a magic section of imp cache base pointers. We need these to
- // offset everything else from
- const CacheBuilder::CacheCoalescedText::StringSection& methodNames = coalescedText.getSectionData("__objc_methname");
- uint64_t selectorStringVMAddr = methodNames.bufferVMAddr;
- uint64_t selectorStringVMSize = methodNames.bufferSize;
- uint64_t impCachesVMSize = 0; // We'll calculate this later
-
- uint64_t optRODataRemainingBeforeImpCaches = optRORemaining;
-
- timeRecorder.pushTimedSection();
-
- uint8_t* inlinedSelectorsStart = optRWData;
- uint8_t* inlinedSelectorsEnd = optRWData;
-
- int impCachesVersion = 1;
-
- uint64_t pointersVMAddr = 0;
- if (optImpCachesPointerSection) {
- if (optImpCachesPointerSection->size() < sizeof(objc_opt::objc_opt_pointerlist_tt<pint_t>)) {
- diag.warning("libobjc's imp cache pointer list section is too small (metadata not optimized)");
- return;
- }
-
- dyld3::MachOAnalyzer::FoundSymbol foundInfo;
- bool found = ((dyld3::MachOAnalyzer*)libobjcMH)->findExportedSymbol(diag, "_objc_opt_preopt_caches_version", false, foundInfo, nullptr);
-
- if (found) {
- impCachesVersion = *(int*)((uint8_t*)libobjcMH + foundInfo.value);
- found = ((dyld3::MachOAnalyzer*)libobjcMH)->findExportedSymbol(diag, "_objc_opt_offsets", false, foundInfo, nullptr);
- if (!found) {
- diag.error("libobjc's imp cache pointer list not found (metadata not optimized)");
- return;
- }
- pointersVMAddr = ((dyld3::MachOAnalyzer*)libobjcMH)->preferredLoadAddress() + foundInfo.value;
- } else {
- impCachesVersion = 1;
- pointersVMAddr = optImpCachesPointerSection->addr();
- }
- }
-
- if (impCachesSuccess) {
- emitIMPCaches<P>(cacheAccessor, allDylibs, sizeSortedDylibs, relativeMethodListBaseAddress,
- selectorStringVMAddr, optROData, optRORemaining, optRWData, optRWRemaining,
- *objcASLRTracker, inlinedSelectors, inlinedSelectorsStart, inlinedSelectorsEnd, impCachesVersion, diag, timeRecorder);
- }
-
- uint8_t* alignedROData = alignPointer(optROData);
- optRORemaining -= (alignedROData - optROData);
- optROData = alignedROData;
-
- impCachesVMSize = optRODataRemainingBeforeImpCaches - optRORemaining;
- timeRecorder.recordTime("emit IMP caches");
- timeRecorder.popTimedSection();
-
- diag.verbose("[IMP Caches] Imp caches size: %'lld bytes\n\n", impCachesVMSize);
-
- // Update the pointers in the pointer list section
- if (optImpCachesPointerSection) {
- auto *impCachePointers = (objc_opt_imp_caches_pointerlist_tt<pint_t> *)cacheAccessor.contentForVMAddr(pointersVMAddr);
- impCachePointers->selectorStringVMAddrStart = (pint_t)selectorStringVMAddr;
- impCachePointers->selectorStringVMAddrEnd = (pint_t)(selectorStringVMAddr + selectorStringVMSize);
- impCachePointers->inlinedSelectorsVMAddrStart = (pint_t)cacheAccessor.vmAddrForContent(inlinedSelectorsStart);
- impCachePointers->inlinedSelectorsVMAddrEnd = (pint_t)cacheAccessor.vmAddrForContent(inlinedSelectorsEnd);
-
- objcASLRTracker->add(&impCachePointers->selectorStringVMAddrStart);
- objcASLRTracker->add(&impCachePointers->selectorStringVMAddrEnd);
- objcASLRTracker->add(&impCachePointers->inlinedSelectorsVMAddrStart);
- objcASLRTracker->add(&impCachePointers->inlinedSelectorsVMAddrEnd);
- }
-
- // Collect flags.
- uint32_t headerFlags = 0;
- if (forProduction) {
- headerFlags |= objc_opt::IsProduction;
- }
- if (noMissingWeakSuperclasses) {
- headerFlags |= objc_opt::NoMissingWeakSuperclasses;
- }
- headerFlags |= objc_opt::LargeSharedCache;
-
-
- // 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());
- if ( libROHeader->version < 15 ) {
- diag.error("Expected libobjc __objc_opt_ro::version to be at least 15");
- return;
- }
- E::set32(libROHeader->flags, headerFlags);
- E::set32(libROHeader->selopt_offset, (uint32_t)(seloptVMAddr - optROSection->addr()));
- E::set32(libROHeader->unused_clsopt_offset, 0);
- 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->unused_protocolopt2_offset, 0);
- E::set32(libROHeader->largeSharedCachesClassOffset, (uint32_t)(clsoptVMAddr - optROSection->addr()));
- E::set32(libROHeader->largeSharedCachesProtocolOffset, (uint32_t)(protocoloptVMAddr - optROSection->addr()));
- E::set64(libROHeader->relativeMethodSelectorBaseAddressOffset, relativeMethodListBaseAddress - 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
- {
- 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 selStringVMAddr = cacheAccessor.vmAddrForContent(selectorString);
-
- if ( (instruction & 0x9F000000) == 0x90000000 ) {
- // ADRP
- int64_t pageDistance = ((selStringVMAddr & ~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 |= (selStringVMAddr & 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
-
-size_t IMPCaches::sizeForImpCacheWithCount(int count) {
- // The architecture should not be relevant here as it's all offsets and fixed int sizes.
- // It was just the most logical place to host this function in.
-
- size_t size64 = IMPCachesEmitter<Pointer64<LittleEndian>>::sizeForImpCacheWithCount(count);
- size_t size32 = IMPCachesEmitter<Pointer32<LittleEndian>>::sizeForImpCacheWithCount(count);
- assert(size64 == size32);
-
- return size64;
-}
-
-void SharedCacheBuilder::optimizeObjC(bool impCachesSuccess, const std::vector<const IMPCaches::Selector*> & inlinedSelectors)
-{
- DyldSharedCache* cache = (DyldSharedCache*)_subCaches.front()._readExecuteRegion.buffer;
- // FIXME: We need to be able to convert relative method lists to direct
- // Mike suggests all relative method lists are offsets from the magic selector
- if ( _archLayout->is64 )
- doOptimizeObjC<Pointer64<LittleEndian>>(cache,
- _options.optimizeStubs,
- _lohTracker,
- _coalescedText,
- _missingWeakImports, _diagnostics,
- _objcReadOnlyBuffer,
- _objcReadOnlyBufferSizeUsed,
- _objcReadOnlyBufferSizeAllocated,
- _objcReadWriteBuffer, _objcReadWriteBufferSizeAllocated,
- _objcReadWriteFileOffset, _sortedDylibs, inlinedSelectors, impCachesSuccess, _timeRecorder);
- else
- doOptimizeObjC<Pointer32<LittleEndian>>(cache,
- _options.optimizeStubs,
- _lohTracker,
- _coalescedText,
- _missingWeakImports, _diagnostics,
- _objcReadOnlyBuffer,
- _objcReadOnlyBufferSizeUsed,
- _objcReadOnlyBufferSizeAllocated,
- _objcReadWriteBuffer, _objcReadWriteBufferSizeAllocated,
- _objcReadWriteFileOffset, _sortedDylibs, inlinedSelectors, impCachesSuccess, _timeRecorder);
-}
-
-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)
-{
- uint8_t pointerSize = _archLayout->is64 ? 8 : 4;
- return 8*imageCount
- + protocolDefCount*12*pointerSize
- + (int)_impCachesBuilder->inlinedSelectors.size() * pointerSize;
-}