+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2015 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 <sys/param.h>
+#include <sys/mman.h>
+
+#include <vector>
+
+#include "Architectures.hpp"
+#include "bitcode.hpp"
+#include "MachOFileAbstraction.hpp"
+#include "MachOTrie.hpp"
+#include "textstub_dylib_file.hpp"
+
+namespace {
+
+///
+/// A token is a light-weight reference to the content of an nmap'ed file. It
+/// doesn't own the data and it doesn't make a copy of it. The referenced data
+/// is only valid as long as the file is mapped in.
+///
+class Token {
+ const char* _p;
+ size_t _size;
+
+ int compareMemory(const char* lhs, const char* rhs, size_t size) const {
+ if (size == 0)
+ return 0;
+ return ::memcmp(lhs, rhs, size);
+ }
+
+public:
+ Token() : _p(nullptr), _size(0) {}
+
+ Token(const char* p) : _p(p), _size(0) {
+ if (p)
+ _size = ::strlen(p);
+ }
+
+ Token(const char* p, size_t s) : _p(p), _size(s) {}
+
+ const char* data() const { return _p; }
+
+ size_t size() const { return _size; }
+
+ std::string str() const { return std::move(std::string(_p, _size)); }
+
+ bool empty() const { return _size == 0; }
+
+ bool operator==(Token other) const {
+ if (_size != other._size)
+ return false;
+ return compareMemory(_p, other._p, _size) == 0;
+ }
+
+ bool operator!=(Token other) const {
+ return !(*this == other);
+ }
+};
+
+///
+/// Simple text-based dynamic library file tokenizer.
+///
+class Tokenizer {
+ const char* _start;
+ const char* _current;
+ const char* _end;
+ Token _currentToken;
+
+ void fetchNextToken();
+ void scanToNextToken();
+ void skip(unsigned distance) {
+ _current += distance;
+ assert(_current <= _end && "Skipped past the end");
+ }
+
+ const char* skipLineBreak(const char* pos) const;
+ bool isDelimiter(const char* pos) const;
+
+public:
+ Tokenizer(const char* data, uint64_t size) : _start(data), _current(data), _end(data + size) {}
+
+ void reset() {
+ _current = _start;
+ fetchNextToken();
+ }
+
+ Token peek() { return _currentToken; }
+ Token next() {
+ Token token = peek();
+ fetchNextToken();
+ return token;
+ }
+};
+
+const char* Tokenizer::skipLineBreak(const char* pos) const
+{
+ if ( pos == _end )
+ return pos;
+
+ // Carriage return.
+ if ( *pos == 0x0D ) {
+ // line feed.
+ if ( pos + 1 != _end && *(pos + 1) == 0x0A)
+ return pos + 2;
+ return pos + 1;
+ }
+
+ // line feed.
+ if ( *pos == 0x0A )
+ return pos + 1;
+
+ return pos;
+}
+
+void Tokenizer::scanToNextToken() {
+ while (true) {
+ while ( isDelimiter(_current) )
+ skip(1);
+
+ const char* i = skipLineBreak(_current);
+ if ( i == _current )
+ break;
+
+ _current = i;
+ }
+}
+
+
+bool Tokenizer::isDelimiter(const char* pos) const {
+ if ( pos == _end )
+ return false;
+ if ( *pos == ' ' || *pos == '\t' || *pos == '\r' || *pos == '\n' || *pos == ',' || *pos == ':' || *pos == '\'' || *pos == '\"' )
+ return true;
+ return false;
+}
+
+void Tokenizer::fetchNextToken() {
+ scanToNextToken();
+
+ if (_current == _end) {
+ _currentToken = Token();
+ return;
+ }
+
+ auto start = _current;
+ while ( !isDelimiter(_current) ) {
+ ++_current;
+ }
+
+ _currentToken = Token(start, _current - start);
+}
+
+///
+/// Representation of a parsed text-based dynamic library file.
+///
+struct DynamicLibrary {
+ Token _installName;
+ uint32_t _currentVersion;
+ uint32_t _compatibilityVersion;
+ uint8_t _swiftVersion;
+ ld::File::ObjcConstraint _objcConstraint;
+ Options::Platform _platform;
+ std::vector<Token> _allowedClients;
+ std::vector<Token> _reexportedLibraries;
+ std::vector<Token> _symbols;
+ std::vector<Token> _classes;
+ std::vector<Token> _ivars;
+ std::vector<Token> _weakDefSymbols;
+ std::vector<Token> _tlvSymbols;
+
+ DynamicLibrary() : _currentVersion(0x10000), _compatibilityVersion(0x10000), _swiftVersion(0),
+ _objcConstraint(ld::File::objcConstraintNone) {}
+};
+
+static uint32_t parseVersionNumber32(Token token) {
+ if ( token.size() >= 128 )
+ throwf("malformed version number");
+
+ char buffer[128];
+ uint32_t x = 0;
+ uint32_t y = 0;
+ uint32_t z = 0;
+ char* end;
+
+ // Make a null-terminated string.
+ ::memcpy(buffer, token.data(), token.size());
+ buffer[token.size()] = '\0';
+
+ x = strtoul(buffer, &end, 10);
+ if ( *end == '.' ) {
+ y = strtoul(&end[1], &end, 10);
+ if ( *end == '.' ) {
+ z = strtoul(&end[1], &end, 10);
+ }
+ }
+ if ( (x > 0xffff) || (y > 0xff) || (z > 0xff) )
+ throwf("malformed 32-bit x.y.z version number: %s", buffer);
+
+ return (x << 16) | ( y << 8 ) | z;
+}
+
+///
+/// A simple text-based dynamic library file parser.
+///
+class TBDFile {
+ Tokenizer _tokenizer;
+
+ Token peek() { return _tokenizer.peek(); }
+ Token next() { return _tokenizer.next(); }
+
+ void expectToken(Token str) {
+ Token token = next();
+ if (token != str)
+ throwf("unexpected token: %s", token.str().c_str());
+ }
+
+ bool hasOptionalToken(Token str) {
+ auto token = peek();
+ if ( token == str ) {
+ next();
+ return true;
+ }
+ return false;
+ }
+
+
+ void parseFlowSequence(std::function<void (Token)> func) {
+ expectToken("[");
+
+ while ( true ) {
+ auto token = peek();
+ if ( token == "]" )
+ break;
+
+ token = next();
+ func(token);
+ }
+
+ expectToken("]");
+ }
+
+ void parseAllowedClients(DynamicLibrary& lib) {
+ if ( !hasOptionalToken("allowed-clients") )
+ return;
+ parseFlowSequence([&](Token name) {
+ lib._allowedClients.emplace_back(name);
+ });
+ }
+
+ void parseReexportedDylibs(DynamicLibrary& lib) {
+ if ( !hasOptionalToken("re-exports") )
+ return;
+ parseFlowSequence([&](Token name) {
+ lib._reexportedLibraries.emplace_back(name);
+ });
+ }
+
+ void parseSymbols(DynamicLibrary& lib) {
+ if ( hasOptionalToken("symbols") ) {
+ parseFlowSequence([&](Token name) {
+ lib._symbols.emplace_back(name);
+ });
+ }
+
+ if ( hasOptionalToken("objc-classes") ) {
+ parseFlowSequence([&](Token name) {
+ lib._classes.emplace_back(name);
+ });
+ }
+
+ if ( hasOptionalToken("objc-ivars") ) {
+ parseFlowSequence([&](Token name) {
+ lib._ivars.emplace_back(name);
+ });
+ }
+
+ if ( hasOptionalToken("weak-def-symbols") ) {
+ parseFlowSequence([&](Token name) {
+ lib._weakDefSymbols.emplace_back(name);
+ });
+ }
+
+ if ( hasOptionalToken("thread-local-symbols") ) {
+ parseFlowSequence([&](Token name) {
+ lib._tlvSymbols.emplace_back(name);
+ });
+ }
+ }
+
+ bool parseArchFlowSequence(Token archName) {
+ expectToken("archs");
+
+ bool foundArch = false;
+ parseFlowSequence([&](Token name) {
+ if ( name == archName )
+ foundArch = true;
+ });
+
+ return foundArch;
+ }
+
+ void parsePlatform(DynamicLibrary& lib) {
+ expectToken("platform");
+
+ auto token = next();
+ if (token == "macosx")
+ lib._platform = Options::kPlatformOSX;
+ else if (token == "ios")
+ lib._platform = Options::kPlatformiOS;
+ else if (token == "watchos")
+ lib._platform = Options::kPlatformWatchOS;
+#if SUPPORT_APPLE_TV
+ else if (token == "tvos")
+ lib._platform = Options::kPlatform_tvOS;
+#endif
+ else
+ lib._platform = Options::kPlatformUnknown;
+ }
+
+ void parseInstallName(DynamicLibrary& lib) {
+ expectToken("install-name");
+
+ lib._installName = next();
+ if ( lib._installName.empty() )
+ throwf("no install name specified");
+ }
+
+ void parseCurrentVersion(DynamicLibrary& lib) {
+ if ( !hasOptionalToken("current-version") )
+ return;
+ lib._currentVersion = parseVersionNumber32(next());
+ }
+
+ void parseCompatibilityVersion(DynamicLibrary& lib) {
+ if ( !hasOptionalToken("compatibility-version") )
+ return;
+ lib._compatibilityVersion = parseVersionNumber32(next());
+ }
+
+ void parseSwiftVersion(DynamicLibrary& lib) {
+ if ( !hasOptionalToken("swift-version") )
+ return;
+ auto token = next();
+ if ( token == "1.0" )
+ lib._swiftVersion = 1;
+ else if ( token == "1.1" )
+ lib._swiftVersion = 2;
+ else if ( token == "2.0" )
+ lib._swiftVersion = 3;
+ else
+ throwf("unsupported Swift ABI version: %s", token.str().c_str());
+ }
+
+ void parseObjCConstraint(DynamicLibrary& lib) {
+ if ( !hasOptionalToken("objc-constraint") )
+ return;
+ auto token = next();
+ if ( token == "none" )
+ lib._objcConstraint = ld::File::objcConstraintNone;
+ else if ( token == "retain_release" )
+ lib._objcConstraint = ld::File::objcConstraintRetainRelease;
+ else if ( token == "retain_release_for_simulator" )
+ lib._objcConstraint = ld::File::objcConstraintRetainReleaseForSimulator;
+ else if ( token == "retain_release_or_gc" )
+ lib._objcConstraint = ld::File::objcConstraintRetainReleaseOrGC;
+ else if ( token == "gc" )
+ lib._objcConstraint = ld::File::objcConstraintGC;
+ else
+ throwf("unexpected token: %s", token.str().c_str());
+ }
+ void parseExportsBlock(DynamicLibrary& lib, Token archName) {
+ if ( !hasOptionalToken("exports") )
+ return;
+
+ if ( !hasOptionalToken("-") )
+ return;
+
+ while ( true ) {
+ if ( !parseArchFlowSequence(archName) ) {
+ Token token;
+ while ( true ) {
+ token = peek();
+ if ( token == "archs" || token == "..." || token.empty() )
+ break;
+ next();
+ }
+ if (token == "..." || token.empty() )
+ break;
+
+ continue;
+ }
+
+ parseAllowedClients(lib);
+ parseReexportedDylibs(lib);
+ parseSymbols(lib);
+ if ( !hasOptionalToken("-") )
+ break;
+ }
+ }
+
+ void parseDocument(DynamicLibrary& lib, Token archName) {
+ if ( !parseArchFlowSequence(archName) )
+ throwf("invalid arch");
+
+ parsePlatform(lib);
+ parseInstallName(lib);
+ parseCurrentVersion(lib);
+ parseCompatibilityVersion(lib);
+ parseSwiftVersion(lib);
+ parseObjCConstraint(lib);
+ parseExportsBlock(lib, archName);
+ }
+
+public:
+ TBDFile(const char* data, uint64_t size) : _tokenizer(data, size) {}
+
+ DynamicLibrary parseFileForArch(Token archName) {
+ _tokenizer.reset();
+ DynamicLibrary lib;
+ expectToken("---");
+ parseDocument(lib, archName);
+ expectToken("...");
+ return std::move(lib);
+ }
+
+ bool validForArch(Token archName) {
+ _tokenizer.reset();
+ auto token = next();
+ if ( token != "---" )
+ return false;
+ return parseArchFlowSequence(archName);
+ }
+
+ void dumpTokens() {
+ _tokenizer.reset();
+ Token token;
+ do {
+ token = next();
+ printf("token: %s\n", token.str().c_str());
+ } while ( !token.empty() );
+ }
+};
+
+} // end anonymous namespace
+
+namespace textstub {
+namespace dylib {
+
+// forward reference
+template <typename A> class File;
+
+
+//
+// An ExportAtom has no content. It exists so that the linker can track which imported
+// symbols came from which dynamic libraries.
+//
+template <typename A>
+class ExportAtom : public ld::Atom
+{
+public:
+ ExportAtom(const File<A>& f, const char* nm, bool weakDef, bool tlv)
+ : ld::Atom(f._importProxySection, ld::Atom::definitionProxy,
+ (weakDef? ld::Atom::combineByName : ld::Atom::combineNever),
+ ld::Atom::scopeLinkageUnit,
+ (tlv ? ld::Atom::typeTLV : ld::Atom::typeUnclassified),
+ symbolTableNotIn, false, false, false, ld::Atom::Alignment(0)),
+ _file(f), _name(nm) {}
+ // overrides of ld::Atom
+ virtual const ld::File* file() const { return &_file; }
+ virtual const char* name() const { return _name; }
+ virtual uint64_t size() const { return 0; }
+ virtual uint64_t objectAddress() const { return 0; }
+ virtual void copyRawContent(uint8_t buffer[]) const { }
+ virtual void setScope(Scope) { }
+
+protected:
+ typedef typename A::P P;
+ typedef typename A::P::uint_t pint_t;
+
+ virtual ~ExportAtom() {}
+
+ const File<A>& _file;
+ const char* _name;
+};
+
+
+//
+// The reader for a dylib extracts all exported symbols names from the memory-mapped
+// dylib, builds a hash table, then unmaps the file. This is an important memory
+// savings for large dylibs.
+//
+template <typename A>
+class File : public ld::dylib::File
+{
+public:
+ static bool validFile(const uint8_t* fileContent, bool executableOrDylib);
+ File(const uint8_t* fileContent, uint64_t fileLength, const char* path,
+ time_t mTime, ld::File::Ordinal ordinal, bool linkingFlatNamespace,
+ bool hoistImplicitPublicDylibs, Options::Platform platform,
+ cpu_type_t cpuType, const char* archName, uint32_t linkMinOSVersion,
+ bool allowSimToMacOSX, bool addVers, bool buildingForSimulator,
+ bool logAllFiles, const char* installPath, bool indirectDylib);
+ virtual ~File() {}
+
+ // overrides of ld::File
+ virtual bool forEachAtom(ld::File::AtomHandler&) const;
+ virtual bool justInTimeforEachAtom(const char* name, ld::File::AtomHandler&) const;
+ virtual ld::File::ObjcConstraint objCConstraint() const { return _objcConstraint; }
+ virtual uint8_t swiftVersion() const { return _swiftVersion; }
+
+ // overrides of ld::dylib::File
+ virtual void processIndirectLibraries(ld::dylib::File::DylibHandler*, bool);
+ virtual bool providedExportAtom() const { return _providedAtom; }
+ virtual const char* parentUmbrella() const { return nullptr; }
+ virtual const std::vector<const char*>* allowableClients() const { return _allowableClients.size() != 0 ? &_allowableClients : nullptr; }
+ virtual bool hasWeakExternals() const { return _hasWeakExports; }
+ virtual bool deadStrippable() const { return false; }
+ virtual bool hasPublicInstallName() const{ return _hasPublicInstallName; }
+ virtual bool hasWeakDefinition(const char* name) const;
+ virtual bool allSymbolsAreWeakImported() const;
+ virtual bool installPathVersionSpecific() const { return _installPathOverride; }
+ // All text-based stubs are per definition AppExtensionSafe.
+ virtual bool appExtensionSafe() const { return true; };
+ virtual ld::Bitcode* getBitcode() const { return _bitcode.get(); }
+
+
+protected:
+ virtual void assertNoReExportCycles(ReExportChain*) const;
+
+private:
+ typedef typename A::P P;
+ typedef typename A::P::E E;
+ typedef typename A::P::uint_t pint_t;
+
+ friend class ExportAtom<A>;
+
+ struct CStringHash {
+ std::size_t operator()(const char* __s) const {
+ unsigned long __h = 0;
+ for ( ; *__s; ++__s)
+ __h = 5 * __h + *__s;
+ return size_t(__h);
+ };
+ };
+ struct AtomAndWeak { ld::Atom* atom; bool weakDef; bool tlv; };
+ typedef std::unordered_map<const char*, AtomAndWeak, ld::CStringHash, ld::CStringEquals> NameToAtomMap;
+ typedef std::unordered_set<const char*, CStringHash, ld::CStringEquals> NameSet;
+
+ struct Dependent { const char* path; File<A>* dylib; };
+
+ virtual std::pair<bool, bool> hasWeakDefinitionImpl(const char* name) const;
+ virtual bool containsOrReExports(const char* name, bool& weakDef, bool& tlv, uint64_t& address) const;
+
+ void buildExportHashTable(const DynamicLibrary &lib);
+ bool isPublicLocation(const char* pth);
+ bool wrongOS() { return _wrongOS; }
+ void addSymbol(const char* name, bool weak, bool tlv);
+
+ const Options::Platform _platform;
+ cpu_type_t _cpuType;
+ const uint32_t _linkMinOSVersion;
+ const bool _allowSimToMacOSXLinking;
+ const bool _addVersionLoadCommand;
+ bool _linkingFlat;
+ bool _implicitlyLinkPublicDylibs;
+ ld::File::ObjcConstraint _objcConstraint;
+ uint8_t _swiftVersion;
+ ld::Section _importProxySection;
+ ld::Section _flatDummySection;
+ std::vector<Dependent> _dependentDylibs;
+ std::vector<const char*> _allowableClients;
+ mutable NameToAtomMap _atoms;
+ NameSet _ignoreExports;
+ bool _noRexports;
+ bool _hasWeakExports;
+ bool _hasPublicInstallName;
+ mutable bool _providedAtom;
+ bool _wrongOS;
+ bool _installPathOverride;
+ bool _indirectDylibsProcessed;
+ std::unique_ptr<ld::Bitcode> _bitcode;
+ static bool _s_logHashtable;
+};
+
+template <typename A>
+bool File<A>::_s_logHashtable = false;
+
+
+template <typename A>
+File<A>::File(const uint8_t* fileContent, uint64_t fileLength, const char* path, time_t mTime,
+ ld::File::Ordinal ord, bool linkingFlatNamespace, bool hoistImplicitPublicDylibs,
+ Options::Platform platform, cpu_type_t cpuType, const char* archName,
+ uint32_t linkMinOSVersion, bool allowSimToMacOSX, bool addVers,
+ bool buildingForSimulator, bool logAllFiles, const char* targetInstallPath,
+ bool indirectDylib)
+ : ld::dylib::File(strdup(path), mTime, ord), _platform(platform), _cpuType(cpuType),
+ _linkMinOSVersion(linkMinOSVersion), _allowSimToMacOSXLinking(allowSimToMacOSX),
+ _addVersionLoadCommand(addVers), _linkingFlat(linkingFlatNamespace),
+ _implicitlyLinkPublicDylibs(hoistImplicitPublicDylibs),
+ _objcConstraint(ld::File::objcConstraintNone), _swiftVersion(0),
+ _importProxySection("__TEXT", "__import", ld::Section::typeImportProxies, true),
+ _flatDummySection("__LINKEDIT", "__flat_dummy", ld::Section::typeLinkEdit, true),
+ _noRexports(false), _hasWeakExports(false),
+ _hasPublicInstallName(false), _providedAtom(false), _wrongOS(false),
+ _installPathOverride(false), _indirectDylibsProcessed(false),
+ _bitcode(new ld::Bitcode(nullptr, 0))
+{
+ // write out path for -t option
+ if ( logAllFiles )
+ printf("%s\n", path);
+
+ TBDFile stub((const char*)fileContent, fileLength);
+ auto lib = stub.parseFileForArch(archName);
+
+ _noRexports = lib._reexportedLibraries.empty();
+ _hasWeakExports = !lib._weakDefSymbols.empty();
+ _dylibInstallPath = strdup(lib._installName.str().c_str());
+ _dylibCurrentVersion = lib._currentVersion;
+ _dylibCompatibilityVersion = lib._compatibilityVersion;
+ _swiftVersion = lib._swiftVersion;
+ _objcConstraint = lib._objcConstraint;
+ _hasPublicInstallName = isPublicLocation(_dylibInstallPath);
+
+ for (auto &client : lib._allowedClients)
+ _allowableClients.push_back(strdup(client.str().c_str()));
+
+ // <rdar://problem/20659505> [TAPI] Don't hoist "public" (in /usr/lib/) dylibs that should not be directly linked
+ if ( !_allowableClients.empty() )
+ _hasPublicInstallName = false;
+
+ if ( (lib._platform != platform) && (platform != Options::kPlatformUnknown) ) {
+ _wrongOS = true;
+ if ( _addVersionLoadCommand && !indirectDylib ) {
+ if ( buildingForSimulator ) {
+ if ( !_allowSimToMacOSXLinking )
+ throwf("building for %s simulator, but linking against dylib built for %s (%s).",
+ Options::platformName(platform), Options::platformName(lib._platform), path);
+ } else {
+ throwf("building for %s, but linking against dylib built for %s (%s).",
+ Options::platformName(platform), Options::platformName(lib._platform), path);
+ }
+ }
+ }
+
+ _dependentDylibs.reserve(lib._reexportedLibraries.size());
+ for ( auto& reexport : lib._reexportedLibraries ) {
+ Dependent entry;
+ entry.path = strdup(reexport.str().c_str());
+ entry.dylib = nullptr;
+ if ( (targetInstallPath == nullptr) || (strcmp(targetInstallPath, entry.path) != 0) )
+ _dependentDylibs.push_back(entry);
+ }
+
+ // build hash table
+ buildExportHashTable(lib);
+
+ munmap((caddr_t)fileContent, fileLength);
+}
+
+template <typename A>
+void File<A>::buildExportHashTable(const DynamicLibrary& lib) {
+ if ( _s_logHashtable )
+ fprintf(stderr, "ld: building hashtable from text-stub info in %s\n", this->path());
+
+ for (auto &sym : lib._symbols)
+ addSymbol(sym.str().c_str(), /*weak=*/false, /*tlv=*/false);
+
+#if SUPPORT_ARCH_i386
+ if (_platform == Options::kPlatformOSX && _cpuType == CPU_TYPE_I386) {
+ for (auto &sym : lib._classes)
+ addSymbol((".objc_class_name" + sym.str()).c_str(), /*weak=*/false, /*tlv=*/false);
+ } else {
+ for (auto &sym : lib._classes) {
+ addSymbol(("_OBJC_CLASS_$" + sym.str()).c_str(), /*weak=*/false, /*tlv=*/false);
+ addSymbol(("_OBJC_METACLASS_$" + sym.str()).c_str(), /*weak=*/false, /*tlv=*/false);
+ }
+ }
+#else
+ for (auto &sym : lib._classes) {
+ addSymbol(("_OBJC_CLASS_$" + sym.str()).c_str(), /*weak=*/false, /*tlv=*/false);
+ addSymbol(("_OBJC_METACLASS_$" + sym.str()).c_str(), /*weak=*/false, /*tlv=*/false);
+ }
+#endif
+
+ for (auto &sym : lib._ivars)
+ addSymbol(("_OBJC_IVAR_$" + sym.str()).c_str(), /*weak=*/false, /*tlv=*/false);
+
+ for (auto &sym : lib._weakDefSymbols)
+ addSymbol(sym.str().c_str(), /*weak=*/true, /*tlv=*/false);
+
+ for (auto &sym : lib._tlvSymbols)
+ addSymbol(sym.str().c_str(), /*weak=*/false, /*tlv=*/true);
+}
+
+
+template <typename A>
+void File<A>::addSymbol(const char* name, bool weakDef, bool tlv)
+{
+ // symbols that start with $ld$ are meta-data to the static linker
+ // <rdar://problem/5182537> need way for ld and dyld to see different exported symbols in a dylib
+ if ( strncmp(name, "$ld$", 4) == 0 ) {
+ // $ld$ <action> $ <condition> $ <symbol-name>
+ const char* symAction = &name[4];
+ const char* symCond = strchr(symAction, '$');
+ if ( symCond != nullptr ) {
+ char curOSVers[16];
+ sprintf(curOSVers, "$os%d.%d$", (_linkMinOSVersion >> 16), ((_linkMinOSVersion >> 8) & 0xFF));
+ if ( strncmp(symCond, curOSVers, strlen(curOSVers)) == 0 ) {
+ const char* symName = strchr(&symCond[1], '$');
+ if ( symName != nullptr ) {
+ ++symName;
+ if ( strncmp(symAction, "hide$", 5) == 0 ) {
+ if ( _s_logHashtable )
+ fprintf(stderr, " adding %s to ignore set for %s\n", symName, this->path());
+ _ignoreExports.insert(strdup(symName));
+ return;
+ }
+ else if ( strncmp(symAction, "add$", 4) == 0 ) {
+ this->addSymbol(symName, weakDef, false);
+ return;
+ }
+ else if ( strncmp(symAction, "install_name$", 13) == 0 ) {
+ _dylibInstallPath = strdup(symName);
+ _installPathOverride = true;
+ return;
+ }
+ else if ( strncmp(symAction, "compatibility_version$", 22) == 0 ) {
+ _dylibCompatibilityVersion = parseVersionNumber32(symName);
+ return;
+ }
+ else {
+ warning("bad symbol action: %s in dylib %s", name, this->path());
+ }
+ }
+ }
+ }
+ else {
+ warning("bad symbol condition: %s in dylib %s", name, this->path());
+ }
+ }
+
+ // add symbol as possible export if we are not supposed to ignore it
+ if ( _ignoreExports.count(name) == 0 ) {
+ AtomAndWeak bucket;
+ bucket.atom = nullptr;
+ bucket.weakDef = weakDef;
+ bucket.tlv = tlv;
+ if ( _s_logHashtable )
+ fprintf(stderr, " adding %s to hash table for %s\n", name, this->path());
+ _atoms[strdup(name)] = bucket;
+ }
+}
+
+
+template <typename A>
+bool File<A>::forEachAtom(ld::File::AtomHandler& handler) const
+{
+ handler.doFile(*this);
+ return false;
+}
+
+
+template <typename A>
+std::pair<bool, bool> File<A>::hasWeakDefinitionImpl(const char* name) const
+{
+ const auto pos = _atoms.find(name);
+ if ( pos != _atoms.end() )
+ return std::make_pair(true, pos->second.weakDef);
+
+ // look in children that I re-export
+ for (const auto &dep : _dependentDylibs) {
+ auto ret = dep.dylib->hasWeakDefinitionImpl(name);
+ if ( ret.first )
+ return ret;
+ }
+ return std::make_pair(false, false);
+}
+
+
+template <typename A>
+bool File<A>::hasWeakDefinition(const char* name) const
+{
+ // if supposed to ignore this export, then pretend I don't have it
+ if ( _ignoreExports.count(name) != 0 )
+ return false;
+
+ return hasWeakDefinitionImpl(name).second;
+}
+
+
+// <rdar://problem/5529626> If only weak_import symbols are used, linker should use LD_LOAD_WEAK_DYLIB
+template <typename A>
+bool File<A>::allSymbolsAreWeakImported() const
+{
+ bool foundNonWeakImport = false;
+ bool foundWeakImport = false;
+ for (const auto &it : _atoms) {
+ const ld::Atom* atom = it.second.atom;
+ if ( atom != nullptr ) {
+ if ( atom->weakImported() )
+ foundWeakImport = true;
+ else
+ foundNonWeakImport = true;
+ }
+ }
+
+ // don't automatically weak link dylib with no imports
+ // so at least one weak import symbol and no non-weak-imported symbols must be found
+ return foundWeakImport && !foundNonWeakImport;
+}
+
+
+template <typename A>
+bool File<A>::containsOrReExports(const char* name, bool& weakDef, bool& tlv, uint64_t& addr) const
+{
+ if ( _ignoreExports.count(name) != 0 )
+ return false;
+
+ // check myself
+ const auto pos = _atoms.find(name);
+ if ( pos != _atoms.end() ) {
+ weakDef = pos->second.weakDef;
+ tlv = pos->second.tlv;
+ addr = 0;
+ return true;
+ }
+
+ // check dylibs I re-export
+ for (const auto& lib : _dependentDylibs) {
+ if ( !lib.dylib->implicitlyLinked() ) {
+ if ( lib.dylib->containsOrReExports(name, weakDef, tlv, addr) )
+ return true;
+ }
+ }
+
+ return false;
+}
+
+
+template <typename A>
+bool File<A>::justInTimeforEachAtom(const char* name, ld::File::AtomHandler& handler) const
+{
+ // if supposed to ignore this export, then pretend I don't have it
+ if ( _ignoreExports.count(name) != 0 )
+ return false;
+
+
+ AtomAndWeak bucket;
+ uint64_t addr;
+ if ( this->containsOrReExports(name, bucket.weakDef, bucket.tlv, addr) ) {
+ bucket.atom = new ExportAtom<A>(*this, name, bucket.weakDef, bucket.tlv);
+ _atoms[name] = bucket;
+ _providedAtom = true;
+ if ( _s_logHashtable )
+ fprintf(stderr, "getJustInTimeAtomsFor: %s found in %s\n", name, this->path());
+ // call handler with new export atom
+ handler.doAtom(*bucket.atom);
+ return true;
+ }
+
+ return false;
+}
+
+
+
+template <typename A>
+bool File<A>::isPublicLocation(const char* path)
+{
+ // -no_implicit_dylibs disables this optimization
+ if ( ! _implicitlyLinkPublicDylibs )
+ return false;
+
+ // /usr/lib is a public location
+ if ( (strncmp(path, "/usr/lib/", 9) == 0) && (strchr(&path[9], '/') == nullptr) )
+ return true;
+
+ // /System/Library/Frameworks/ is a public location
+ if ( strncmp(path, "/System/Library/Frameworks/", 27) == 0 ) {
+ const char* frameworkDot = strchr(&path[27], '.');
+ // but only top level framework
+ // /System/Library/Frameworks/Foo.framework/Versions/A/Foo ==> true
+ // /System/Library/Frameworks/Foo.framework/Resources/libBar.dylib ==> false
+ // /System/Library/Frameworks/Foo.framework/Frameworks/Bar.framework/Bar ==> false
+ // /System/Library/Frameworks/Foo.framework/Frameworks/Xfoo.framework/XFoo ==> false
+ if ( frameworkDot != nullptr ) {
+ int frameworkNameLen = frameworkDot - &path[27];
+ if ( strncmp(&path[strlen(path)-frameworkNameLen-1], &path[26], frameworkNameLen+1) == 0 )
+ return true;
+ }
+ }
+
+ return false;
+}
+
+template <typename A>
+void File<A>::processIndirectLibraries(ld::dylib::File::DylibHandler* handler, bool addImplicitDylibs)
+{
+ // only do this once
+ if ( _indirectDylibsProcessed )
+ return;
+
+ const static bool log = false;
+ if ( log ) fprintf(stderr, "processIndirectLibraries(%s)\n", this->installPath());
+ if ( _linkingFlat ) {
+ for (auto& lib : _dependentDylibs) {
+ lib.dylib = (File<A>*)handler->findDylib(lib.path, this->path());
+ }
+ }
+ else if ( _noRexports ) {
+ // MH_NO_REEXPORTED_DYLIBS bit set, then nothing to do
+ }
+ else {
+ // two-level, might have re-exports
+ for (auto& lib : _dependentDylibs) {
+ if ( log )
+ fprintf(stderr, "processIndirectLibraries() parent=%s, child=%s\n", this->installPath(), lib.path);
+ // a LC_REEXPORT_DYLIB, LC_SUB_UMBRELLA or LC_SUB_LIBRARY says we re-export this child
+ lib.dylib = (File<A>*)handler->findDylib(lib.path, this->path());
+ if ( lib.dylib->hasPublicInstallName() && !lib.dylib->wrongOS() ) {
+ // promote this child to be automatically added as a direct dependent if this already is
+ if ( (this->explicitlyLinked() || this->implicitlyLinked()) && (strcmp(lib.path, lib.dylib->installPath()) == 0) ) {
+ if ( log )
+ fprintf(stderr, "processIndirectLibraries() implicitly linking %s\n", lib.dylib->installPath());
+ lib.dylib->setImplicitlyLinked();
+ }
+ else if ( lib.dylib->explicitlyLinked() || lib.dylib->implicitlyLinked() ) {
+ if ( log )
+ fprintf(stderr, "processIndirectLibraries() parent is not directly linked, but child is, so no need to re-export child\n");
+ } else {
+ if ( log )
+ fprintf(stderr, "processIndirectLibraries() parent is not directly linked, so parent=%s will re-export child=%s\n", this->installPath(), lib.path);
+ }
+ } else {
+ // add all child's symbols to me
+ if ( log )
+ fprintf(stderr, "processIndirectLibraries() child is not public, so parent=%s will re-export child=%s\n", this->installPath(), lib.path);
+ }
+ }
+ }
+
+ // check for re-export cycles
+ ReExportChain chain;
+ chain.prev = nullptr;
+ chain.file = this;
+ this->assertNoReExportCycles(&chain);
+
+ _indirectDylibsProcessed = true;
+}
+
+template <typename A>
+void File<A>::assertNoReExportCycles(ReExportChain* prev) const
+{
+ // recursively check my re-exported dylibs
+ ReExportChain chain;
+ chain.prev = prev;
+ chain.file = this;
+ for (const auto& dep : _dependentDylibs) {
+ ld::File* child = dep.dylib;
+ // check child is not already in chain
+ for (ReExportChain* p = prev; p != nullptr; p = p->prev) {
+ if ( p->file == child )
+ throwf("cycle in dylib re-exports with %s and %s", child->path(), this->path());
+ }
+ if ( dep.dylib != nullptr )
+ dep.dylib->assertNoReExportCycles(&chain);
+ }
+}
+
+
+template <typename A>
+class Parser
+{
+public:
+ typedef typename A::P P;
+
+ static bool validFile(const uint8_t* fileContent, uint64_t fileLength, const std::string &path, const char* archName);
+ static ld::dylib::File* parse(const uint8_t* fileContent, uint64_t fileLength, const char* path,
+ time_t mTime, ld::File::Ordinal ordinal, const Options& opts,
+ bool indirectDylib) {
+ return new File<A>(fileContent, fileLength, path, mTime, ordinal,
+ opts.flatNamespace(),
+ opts.implicitlyLinkIndirectPublicDylibs(),
+ opts.platform(),
+ opts.architecture(),
+ opts.architectureName(),
+ opts.minOSversion(),
+ opts.allowSimulatorToLinkWithMacOSX(),
+ opts.addVersionLoadCommand(),
+ opts.targetIOSSimulator(),
+ opts.logAllFiles(),
+ opts.installPath(),
+ indirectDylib);
+ }
+};
+
+template <typename A>
+bool Parser<A>::validFile(const uint8_t* fileContent, uint64_t fileLength, const std::string &path, const char* archName)
+{
+ if ( path.find(".tbd", path.size()-4) == std::string::npos )
+ return false;
+
+ TBDFile stub((const char*)fileContent, fileLength);
+ if ( !stub.validForArch(archName) )
+ throwf("missing required architecture %s in file %s", archName, path.c_str());
+
+ return true;
+}
+
+//
+// main function used by linker to instantiate ld::Files
+//
+ld::dylib::File* parse(const uint8_t* fileContent, uint64_t fileLength, const char* path,
+ time_t modTime, const Options& opts, ld::File::Ordinal ordinal,
+ bool bundleLoader, bool indirectDylib)
+{
+ switch ( opts.architecture() ) {
+#if SUPPORT_ARCH_x86_64
+ case CPU_TYPE_X86_64:
+ if ( Parser<x86_64>::validFile(fileContent, fileLength, path, opts.architectureName()) )
+ return Parser<x86_64>::parse(fileContent, fileLength, path, modTime, ordinal, opts, indirectDylib);
+ break;
+#endif
+#if SUPPORT_ARCH_i386
+ case CPU_TYPE_I386:
+ if ( Parser<x86>::validFile(fileContent, fileLength, path, opts.architectureName()) )
+ return Parser<x86>::parse(fileContent, fileLength, path, modTime, ordinal, opts, indirectDylib);
+ break;
+#endif
+#if SUPPORT_ARCH_arm_any
+ case CPU_TYPE_ARM:
+ if ( Parser<arm>::validFile(fileContent, fileLength, path, opts.architectureName()) )
+ return Parser<arm>::parse(fileContent, fileLength, path, modTime, ordinal, opts, indirectDylib);
+ break;
+#endif
+#if SUPPORT_ARCH_arm64
+ case CPU_TYPE_ARM64:
+ if ( Parser<arm64>::validFile(fileContent, fileLength, path, opts.architectureName()) )
+ return Parser<arm64>::parse(fileContent, fileLength, path, modTime, ordinal, opts, indirectDylib);
+ break;
+#endif
+ }
+ return nullptr;
+}
+
+
+} // namespace dylib
+} // namespace textstub
+
+
projects / apple / ld64.git / commitdiff
