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dyld3/shared-cache/OptimizerLinkedit.cpp dyld-750.6 dyld-852
--- dyld/dyld-750.6/dyld3/shared-cache/OptimizerLinkedit.cpp
+++ dyld/dyld-852/dyld3/shared-cache/OptimizerLinkedit.cpp
@@ -53,7 +53,12 @@
 public:
     // add a string and symbol table entry index to be updated later
     void add(uint32_t symbolIndex, const char* symbolName) {
-        _map[symbolName].push_back(symbolIndex);
+        _map[symbolName].push_back({ symbolIndex, false });
+    }
+
+    // add a string and symbol table entry index to be updated later
+    void addIndirect(uint32_t symbolIndex, const char* symbolName) {
+        _map[symbolName].push_back({ symbolIndex, true });
     }
 
     // copy sorted strings to buffer and update all symbol's string offsets
@@ -66,8 +71,13 @@
             // append string to pool
             strcpy(&dstStringPool[poolOffset], symName.c_str());
             //  set each string offset of each symbol using it
-            for (uint32_t symbolIndex : entry.second) {
-                symbolTable[symbolIndex].set_n_strx(poolOffset);
+            for (std::pair<uint32_t, bool> symbolIndexAndIndirect : entry.second) {
+                if ( symbolIndexAndIndirect.second ) {
+                    // Indirect
+                    symbolTable[symbolIndexAndIndirect.first].set_n_value(poolOffset);
+                } else {
+                    symbolTable[symbolIndexAndIndirect.first].set_n_strx(poolOffset);
+                }
             }
             poolOffset += symName.size() + 1;
         }
@@ -85,7 +95,7 @@
 
 
 private:
-    std::map<std::string, std::vector<uint32_t>> _map;
+    std::map<std::string, std::vector<std::pair<uint32_t, bool>>> _map;
 };
 
 
@@ -103,11 +113,12 @@
 template <typename P>
 class LinkeditOptimizer {
 public:
-                    LinkeditOptimizer(void* cacheBuffer, macho_header<P>* mh, Diagnostics& diag);
+                    LinkeditOptimizer(const void* containerBuffer, macho_header<P>* mh, const char* dylibID,
+                                      Diagnostics& diag);
 
     uint32_t        linkeditSize() { return _linkeditSize; }
     uint64_t        linkeditAddr() { return _linkeditAddr; }
-    const char*     installName() { return _installName; }
+    const char*     dylibID() { return _dylibID; }
     void            copyWeakBindingInfo(uint8_t* newLinkEditContent, uint32_t& offset);
     void            copyLazyBindingInfo(uint8_t* newLinkEditContent, uint32_t& offset);
     void            copyBindingInfo(uint8_t* newLinkEditContent, uint32_t& offset);
@@ -124,6 +135,9 @@
                                        uint32_t sharedSymbolTableStartOffset, uint32_t sharedSymbolTableCount,
                                        uint32_t sharedSymbolStringsOffset, uint32_t sharedSymbolStringsSize);
 
+    typedef CacheBuilder::DylibStripMode DylibStripMode;
+    void            setStripMode(DylibStripMode stripMode);
+
     macho_header<P>*                        machHeader() { return _mh; }
     const std::vector<const char*>          getDownwardDependents() { return _downDependentPaths; }
     const std::vector<const char*>          getAllDependents() { return _allDependentPaths; }
@@ -138,8 +152,11 @@
     const std::vector<macho_segment_command<P>*>&  segCmds() { return _segCmds; }
 
 
-    static void optimizeLinkedit(CacheBuilder& builder);
-    static void mergeLinkedits(CacheBuilder& builder, std::vector<LinkeditOptimizer<P>*>& optimizers);
+    static void optimizeLinkedit(CacheBuilder& builder, const void* containerBuffer,
+                                 CacheBuilder::UnmappedRegion* localSymbolsRegion,
+                                 const std::vector<std::tuple<const mach_header*, const char*, DylibStripMode>>& images);
+    static void mergeLinkedits(CacheBuilder& builder, CacheBuilder::UnmappedRegion* localSymbolsRegion,
+                               std::vector<LinkeditOptimizer<P>*>& optimizers);
 
 private:
 
@@ -147,12 +164,12 @@
     typedef typename P::E E;
 
     macho_header<P>*                        _mh;
-    void*                                   _cacheBuffer;
+    const void*                             _containerBuffer;
     Diagnostics&                            _diagnostics;
     uint32_t                                _linkeditSize        = 0;
     uint64_t                                _linkeditAddr        = 0;
     const uint8_t*                          _linkeditBias       = nullptr;
-    const char*                             _installName        = nullptr;
+    const char*                             _dylibID            = nullptr;
     macho_symtab_command<P>*                _symTabCmd          = nullptr;
     macho_dysymtab_command<P>*              _dynSymTabCmd       = nullptr;
     macho_dyld_info_command<P>*             _dyldInfo           = nullptr;
@@ -182,13 +199,14 @@
     uint32_t                                _newDataInCodeOffset            = 0;
     uint32_t                                _newIndirectSymbolTableOffset   = 0;
     uint64_t                                _dyldSectionAddr                = 0;
+    DylibStripMode                          _stripMode                 = DylibStripMode::stripAll;
 };
 
 
-
-template <typename P>
-LinkeditOptimizer<P>::LinkeditOptimizer(void* cacheBuffer, macho_header<P>* mh, Diagnostics& diag)
-: _mh(mh), _cacheBuffer(cacheBuffer), _diagnostics(diag)
+template <typename P>
+LinkeditOptimizer<P>::LinkeditOptimizer(const void* containerBuffer, macho_header<P>* mh,
+                                        const char* dylibID, Diagnostics& diag)
+: _mh(mh), _dylibID(dylibID), _containerBuffer(containerBuffer), _diagnostics(diag)
 {
     const unsigned origLoadCommandsSize = mh->sizeofcmds();
     unsigned bytesRemaining = origLoadCommandsSize;
@@ -204,9 +222,6 @@
     for (uint32_t i = 0; i < cmdCount; ++i) {
         bool remove = false;
         switch (cmd->cmd()) {
-            case LC_ID_DYLIB:
-                _installName = ((macho_dylib_command<P>*)cmd)->name();
-                break;
             case LC_SYMTAB:
                 _symTabCmd = (macho_symtab_command<P>*)cmd;
                 break;
@@ -309,6 +324,11 @@
     mh->set_sizeofcmds(origLoadCommandsSize - bytesRemaining);
 }
 
+template <typename P>
+void LinkeditOptimizer<P>::setStripMode(DylibStripMode stripMode) {
+    _stripMode = stripMode;
+}
+
 /*
 static void dumpLoadCommands(const uint8_t* mheader)
 {
@@ -412,20 +432,22 @@
     _symTabCmd->set_strsize(sharedSymbolStringsSize);
 
     // update dynamic symbol table to have proper offsets into shared symbol table
-    _dynSymTabCmd->set_ilocalsym(0);
-    _dynSymTabCmd->set_nlocalsym(_newLocalSymbolCount);
-    _dynSymTabCmd->set_iextdefsym(_newExportedSymbolsStartIndex-_newLocalSymbolsStartIndex);
-    _dynSymTabCmd->set_nextdefsym(_newExportedSymbolCount);
-    _dynSymTabCmd->set_iundefsym(_newImportedSymbolsStartIndex-_newLocalSymbolsStartIndex);
-    _dynSymTabCmd->set_nundefsym(_newImportedSymbolCount);
-    _dynSymTabCmd->set_tocoff(0);
-    _dynSymTabCmd->set_ntoc(0);
-    _dynSymTabCmd->set_modtaboff(0);
-    _dynSymTabCmd->set_nmodtab(0);
-    _dynSymTabCmd->set_indirectsymoff(mergedLinkeditStartOffset + _newIndirectSymbolTableOffset);
-    _dynSymTabCmd->set_extreloff(0);
-    _dynSymTabCmd->set_locreloff(0);
-    _dynSymTabCmd->set_nlocrel(0);
+    if ( _dynSymTabCmd != nullptr ) {
+        _dynSymTabCmd->set_ilocalsym(0);
+        _dynSymTabCmd->set_nlocalsym(_newLocalSymbolCount);
+        _dynSymTabCmd->set_iextdefsym(_newExportedSymbolsStartIndex-_newLocalSymbolsStartIndex);
+        _dynSymTabCmd->set_nextdefsym(_newExportedSymbolCount);
+        _dynSymTabCmd->set_iundefsym(_newImportedSymbolsStartIndex-_newLocalSymbolsStartIndex);
+        _dynSymTabCmd->set_nundefsym(_newImportedSymbolCount);
+        _dynSymTabCmd->set_tocoff(0);
+        _dynSymTabCmd->set_ntoc(0);
+        _dynSymTabCmd->set_modtaboff(0);
+        _dynSymTabCmd->set_nmodtab(0);
+        _dynSymTabCmd->set_indirectsymoff(mergedLinkeditStartOffset + _newIndirectSymbolTableOffset);
+        _dynSymTabCmd->set_extreloff(0);
+        _dynSymTabCmd->set_locreloff(0);
+        _dynSymTabCmd->set_nlocrel(0);
+    }
 
     // update dyld info
     if ( _dyldInfo != nullptr ) {
@@ -533,11 +555,27 @@
                                             bool redact, std::vector<LocalSymbolInfo>& localSymbolInfos,
                                             std::vector<macho_nlist<P>>& unmappedLocalSymbols, SortedStringPool<P>& localSymbolsStringPool)
 {
-    LocalSymbolInfo localInfo;
-    localInfo.dylibOffset = (uint32_t)(((uint8_t*)_mh) - (uint8_t*)_cacheBuffer);
+    localSymbolInfos.push_back(LocalSymbolInfo());
+
+    LocalSymbolInfo& localInfo = localSymbolInfos.back();
+    localInfo.dylibOffset = (uint32_t)(((uint8_t*)_mh) - (uint8_t*)_containerBuffer);
     localInfo.nlistStartIndex = (uint32_t)unmappedLocalSymbols.size();
     localInfo.nlistCount = 0;
     _newLocalSymbolsStartIndex = symbolIndex;
+    _newLocalSymbolCount = 0;
+
+    switch (_stripMode) {
+        case CacheBuilder::DylibStripMode::stripNone:
+        case CacheBuilder::DylibStripMode::stripExports:
+            break;
+        case CacheBuilder::DylibStripMode::stripLocals:
+        case CacheBuilder::DylibStripMode::stripAll:
+            return;
+    }
+
+    if ( _dynSymTabCmd == nullptr )
+        return;
+
     const char* strings = (char*)&_linkeditBias[_symTabCmd->stroff()];
     const macho_nlist<P>* const symbolTable = (macho_nlist<P>*)(&_linkeditBias[_symTabCmd->symoff()]);
     const macho_nlist<P>* const firstExport = &symbolTable[_dynSymTabCmd->ilocalsym()];
@@ -570,7 +608,6 @@
     }
     _newLocalSymbolCount = symbolIndex - _newLocalSymbolsStartIndex;
     localInfo.nlistCount = (uint32_t)unmappedLocalSymbols.size() - localInfo.nlistStartIndex;
-    localSymbolInfos.push_back(localInfo);
 }
 
 
@@ -578,6 +615,20 @@
 void LinkeditOptimizer<P>::copyExportedSymbols(uint8_t* newLinkEditContent, SortedStringPool<P>& stringPool, uint32_t& offset, uint32_t& symbolIndex)
 {
     _newExportedSymbolsStartIndex = symbolIndex;
+    _newExportedSymbolCount = 0;
+
+    switch (_stripMode) {
+        case CacheBuilder::DylibStripMode::stripNone:
+        case CacheBuilder::DylibStripMode::stripLocals:
+            break;
+        case CacheBuilder::DylibStripMode::stripExports:
+        case CacheBuilder::DylibStripMode::stripAll:
+            return;
+    }
+
+    if ( _dynSymTabCmd == nullptr )
+        return;
+
     const char* strings = (char*)&_linkeditBias[_symTabCmd->stroff()];
     const macho_nlist<P>* const symbolTable = (macho_nlist<P>*)(&_linkeditBias[_symTabCmd->symoff()]);
     const macho_nlist<P>* const firstExport = &symbolTable[_dynSymTabCmd->iextdefsym()];
@@ -606,6 +657,20 @@
 void LinkeditOptimizer<P>::copyImportedSymbols(uint8_t* newLinkEditContent, SortedStringPool<P>& stringPool, uint32_t& offset, uint32_t& symbolIndex)
 {
     _newImportedSymbolsStartIndex = symbolIndex;
+    _newImportedSymbolCount = 0;
+
+    if ( _dynSymTabCmd == nullptr )
+        return;
+
+    switch (_stripMode) {
+        case CacheBuilder::DylibStripMode::stripNone:
+            break;
+        case CacheBuilder::DylibStripMode::stripLocals:
+        case CacheBuilder::DylibStripMode::stripExports:
+        case CacheBuilder::DylibStripMode::stripAll:
+            return;
+    }
+
     const char* strings = (char*)&_linkeditBias[_symTabCmd->stroff()];
     const macho_nlist<P>* const symbolTable = (macho_nlist<P>*)(&_linkeditBias[_symTabCmd->symoff()]);
     const macho_nlist<P>* const firstImport = &symbolTable[_dynSymTabCmd->iundefsym()];
@@ -630,6 +695,10 @@
 void LinkeditOptimizer<P>::copyIndirectSymbolTable(uint8_t* newLinkEditContent, uint32_t& offset)
 {
     _newIndirectSymbolTableOffset = offset;
+
+    if ( _dynSymTabCmd == nullptr )
+        return;
+
      const uint32_t* const indirectTable = (uint32_t*)&_linkeditBias[_dynSymTabCmd->indirectsymoff()];
     uint32_t* newIndirectTable = (uint32_t*)&newLinkEditContent[offset];
     for (uint32_t i=0; i < _dynSymTabCmd->nindirectsyms(); ++i) {
@@ -643,7 +712,9 @@
 }
 
 template <typename P>
-void LinkeditOptimizer<P>::mergeLinkedits(CacheBuilder& builder, std::vector<LinkeditOptimizer<P>*>& optimizers)
+void LinkeditOptimizer<P>::mergeLinkedits(CacheBuilder& builder,
+                                          CacheBuilder::UnmappedRegion* localSymbolsRegion,
+                                          std::vector<LinkeditOptimizer<P>*>& optimizers)
 {
     // allocate space for new linkedit data
     uint64_t totalUnoptLinkeditsSize = builder._readOnlyRegion.sizeInUse - builder._nonLinkEditReadOnlySize;
@@ -693,9 +764,11 @@
         builder._diagnostics.verbose("  lazy bindings size:      %5uKB\n", (offset-startLazyBindingsInfosOffset)/1024);
     }
 
+    bool unmapLocals = ( builder._options.localSymbolMode == DyldSharedCache::LocalSymbolsMode::unmap );
+
     // copy symbol table entries
     std::vector<macho_nlist<P>> unmappedLocalSymbols;
-    if ( builder._options.excludeLocalSymbols )
+    if ( unmapLocals )
         unmappedLocalSymbols.reserve(0x01000000);
     std::vector<LocalSymbolInfo> localSymbolInfos;
         localSymbolInfos.reserve(optimizers.size());
@@ -705,7 +778,7 @@
     uint32_t sharedSymbolTableExportsCount = 0;
     uint32_t sharedSymbolTableImportsCount = 0;
     for (LinkeditOptimizer<P>* op : optimizers) {
-         op->copyLocalSymbols(newLinkEdit, stringPool, offset, symbolIndex, builder._options.excludeLocalSymbols,
+         op->copyLocalSymbols(newLinkEdit, stringPool, offset, symbolIndex, unmapLocals,
                              localSymbolInfos, unmappedLocalSymbols, localSymbolsStringPool);
         uint32_t x = symbolIndex;
         op->copyExportedSymbols(newLinkEdit, stringPool, offset, symbolIndex);
@@ -747,7 +820,6 @@
     uint64_t newLinkeditAlignedSize = align(offset, 14);
     builder._diagnostics.verbose("  symbol table size:       %5uKB (%d exports, %d imports)\n", (sharedSymbolTableEndOffset-sharedSymbolTableStartOffset)/1024, sharedSymbolTableExportsCount, sharedSymbolTableImportsCount);
     builder._diagnostics.verbose("  symbol string pool size: %5uKB\n", sharedSymbolStringsSize/1024);
-    builder._sharedStringsPoolVmOffset = (uint32_t)((builder._readOnlyRegion.unslidLoadAddress - builder._readExecuteRegion.unslidLoadAddress) + builder._nonLinkEditReadOnlySize + sharedSymbolStringsOffset);
 
     // overwrite mapped LINKEDIT area in cache with new merged LINKEDIT content
     builder._diagnostics.verbose("LINKEDITS optimized from %uMB to %uMB\n", (uint32_t)totalUnoptLinkeditsSize/(1024*1024), (uint32_t)newLinkeditUnalignedSize/(1024*1024));
@@ -756,7 +828,7 @@
     builder._readOnlyRegion.sizeInUse = builder._nonLinkEditReadOnlySize + newLinkeditAlignedSize;
 
     // overwrite end of un-opt linkedits to create a new unmapped region for local symbols
-    if ( builder._options.excludeLocalSymbols ) {
+    if ( unmapLocals ) {
         const uint32_t entriesOffset = sizeof(dyld_cache_local_symbols_info);
         const uint32_t entriesCount  = (uint32_t)localSymbolInfos.size();
         const uint32_t nlistOffset   = (uint32_t)align(entriesOffset + entriesCount * sizeof(dyld_cache_local_symbols_info), 4); // 16-byte align start
@@ -787,13 +859,10 @@
             ::memcpy(newLocalsSymbolTable, &unmappedLocalSymbols[0], nlistCount*sizeof(macho_nlist<P>));
             // copy string pool
             localSymbolsStringPool.copyPoolAndUpdateOffsets(((char*)infoHeader)+stringsOffset, newLocalsSymbolTable);
-            // update cache header
-            DyldSharedCache* cacheHeader = (DyldSharedCache*)builder._readExecuteRegion.buffer;
-            cacheHeader->header.localSymbolsSize    = localsBufferSize;
             // return buffer of local symbols, caller to free() it
-            builder._localSymbolsRegion.buffer      = (uint8_t*)localsBuffer;
-            builder._localSymbolsRegion.bufferSize  = localsBufferSize;
-            builder._localSymbolsRegion.sizeInUse   = localsBufferSize;
+            localSymbolsRegion->buffer      = (uint8_t*)localsBuffer;
+            localSymbolsRegion->bufferSize  = localsBufferSize;
+            localSymbolsRegion->sizeInUse   = localsBufferSize;
         }
         else {
             builder._diagnostics.warning("could not allocate local symbols");
@@ -812,14 +881,16 @@
 
 
 template <typename P>
-void LinkeditOptimizer<P>::optimizeLinkedit(CacheBuilder& builder)
-{
-    DyldSharedCache* cache = (DyldSharedCache*)builder._readExecuteRegion.buffer;
+void LinkeditOptimizer<P>::optimizeLinkedit(CacheBuilder& builder, const void* containerBuffer,
+                                            CacheBuilder::UnmappedRegion* localSymbolsRegion,
+                                            const std::vector<std::tuple<const mach_header*, const char*, DylibStripMode>>& images)
+{
     // construct a LinkeditOptimizer for each image
     __block std::vector<LinkeditOptimizer<P>*> optimizers;
-    cache->forEachImage(^(const mach_header* mh, const char*) {
-        optimizers.push_back(new LinkeditOptimizer<P>(cache, (macho_header<P>*)mh, builder._diagnostics));
-    });
+    for (std::tuple<const mach_header*, const char*, DylibStripMode> image : images) {
+        optimizers.push_back(new LinkeditOptimizer<P>(containerBuffer, (macho_header<P>*)std::get<0>(image), std::get<1>(image), builder._diagnostics));
+        optimizers.back()->setStripMode(std::get<2>(image));
+    }
 #if 0
     // add optimizer for each branch pool
     for (uint64_t poolOffset : branchPoolOffsets) {
@@ -828,22 +899,26 @@
     }
 #endif
     // merge linkedit info
-    mergeLinkedits(builder, optimizers);
+    mergeLinkedits(builder, localSymbolsRegion, optimizers);
 
     // delete optimizers
     for (LinkeditOptimizer<P>* op : optimizers)
         delete op;
 }
 
-void CacheBuilder::optimizeLinkedit()
-{
+void CacheBuilder::optimizeLinkedit(UnmappedRegion* localSymbolsRegion,
+                                    const std::vector<std::tuple<const mach_header*, const char*, DylibStripMode>>& images)
+{
+    const void* buffer = (const void*)_fullAllocatedBuffer;
     if ( _is64 ) {
-        return LinkeditOptimizer<Pointer64<LittleEndian>>::optimizeLinkedit(*this);
+        return LinkeditOptimizer<Pointer64<LittleEndian>>::optimizeLinkedit(*this, buffer,
+                                                                            localSymbolsRegion, images);
     }
     else {
-         return LinkeditOptimizer<Pointer32<LittleEndian>>::optimizeLinkedit(*this);
-    }
-}
-
-
-
+         return LinkeditOptimizer<Pointer32<LittleEndian>>::optimizeLinkedit(*this, buffer,
+                                                                             localSymbolsRegion, images);
+    }
+}
+
+
+