Index: vendor/lld/dist-release_70/COFF/Chunks.h =================================================================== --- vendor/lld/dist-release_70/COFF/Chunks.h (revision 340121) +++ vendor/lld/dist-release_70/COFF/Chunks.h (revision 340122) @@ -1,429 +1,431 @@ //===- Chunks.h -------------------------------------------------*- C++ -*-===// // // The LLVM Linker // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #ifndef LLD_COFF_CHUNKS_H #define LLD_COFF_CHUNKS_H #include "Config.h" #include "InputFiles.h" #include "lld/Common/LLVM.h" #include "llvm/ADT/ArrayRef.h" #include "llvm/ADT/iterator.h" #include "llvm/ADT/iterator_range.h" #include "llvm/MC/StringTableBuilder.h" #include "llvm/Object/COFF.h" #include #include namespace lld { namespace coff { using llvm::COFF::ImportDirectoryTableEntry; using llvm::object::COFFSymbolRef; using llvm::object::SectionRef; using llvm::object::coff_relocation; using llvm::object::coff_section; class Baserel; class Defined; class DefinedImportData; class DefinedRegular; class ObjFile; class OutputSection; class Symbol; // Mask for permissions (discardable, writable, readable, executable, etc). const uint32_t PermMask = 0xFE000000; // Mask for section types (code, data, bss). const uint32_t TypeMask = 0x000000E0; // A Chunk represents a chunk of data that will occupy space in the // output (if the resolver chose that). It may or may not be backed by // a section of an input file. It could be linker-created data, or // doesn't even have actual data (if common or bss). class Chunk { public: enum Kind { SectionKind, OtherKind }; Kind kind() const { return ChunkKind; } virtual ~Chunk() = default; // Returns the size of this chunk (even if this is a common or BSS.) virtual size_t getSize() const = 0; // Write this chunk to a mmap'ed file, assuming Buf is pointing to // beginning of the file. Because this function may use RVA values // of other chunks for relocations, you need to set them properly // before calling this function. virtual void writeTo(uint8_t *Buf) const {} // Called by the writer after an RVA is assigned, but before calling // getSize(). virtual void finalizeContents() {} // The writer sets and uses the addresses. uint64_t getRVA() const { return RVA; } void setRVA(uint64_t V) { RVA = V; } // Returns true if this has non-zero data. BSS chunks return // false. If false is returned, the space occupied by this chunk // will be filled with zeros. virtual bool hasData() const { return true; } // Returns readable/writable/executable bits. virtual uint32_t getOutputCharacteristics() const { return 0; } // Returns the section name if this is a section chunk. // It is illegal to call this function on non-section chunks. virtual StringRef getSectionName() const { llvm_unreachable("unimplemented getSectionName"); } // An output section has pointers to chunks in the section, and each // chunk has a back pointer to an output section. void setOutputSection(OutputSection *O) { Out = O; } OutputSection *getOutputSection() const { return Out; } // Windows-specific. // Collect all locations that contain absolute addresses for base relocations. virtual void getBaserels(std::vector *Res) {} // Returns a human-readable name of this chunk. Chunks are unnamed chunks of // bytes, so this is used only for logging or debugging. virtual StringRef getDebugName() { return ""; } // The alignment of this chunk. The writer uses the value. uint32_t Alignment = 1; protected: Chunk(Kind K = OtherKind) : ChunkKind(K) {} const Kind ChunkKind; // The RVA of this chunk in the output. The writer sets a value. uint64_t RVA = 0; // The output section for this chunk. OutputSection *Out = nullptr; public: // The offset from beginning of the output section. The writer sets a value. uint64_t OutputSectionOff = 0; }; // A chunk corresponding a section of an input file. class SectionChunk final : public Chunk { // Identical COMDAT Folding feature accesses section internal data. friend class ICF; public: class symbol_iterator : public llvm::iterator_adaptor_base< symbol_iterator, const coff_relocation *, std::random_access_iterator_tag, Symbol *> { friend SectionChunk; ObjFile *File; symbol_iterator(ObjFile *File, const coff_relocation *I) : symbol_iterator::iterator_adaptor_base(I), File(File) {} public: symbol_iterator() = default; Symbol *operator*() const { return File->getSymbol(I->SymbolTableIndex); } }; SectionChunk(ObjFile *File, const coff_section *Header); static bool classof(const Chunk *C) { return C->kind() == SectionKind; } size_t getSize() const override { return Header->SizeOfRawData; } ArrayRef getContents() const; void writeTo(uint8_t *Buf) const override; bool hasData() const override; uint32_t getOutputCharacteristics() const override; StringRef getSectionName() const override { return SectionName; } void getBaserels(std::vector *Res) override; bool isCOMDAT() const; void applyRelX64(uint8_t *Off, uint16_t Type, OutputSection *OS, uint64_t S, uint64_t P) const; void applyRelX86(uint8_t *Off, uint16_t Type, OutputSection *OS, uint64_t S, uint64_t P) const; void applyRelARM(uint8_t *Off, uint16_t Type, OutputSection *OS, uint64_t S, uint64_t P) const; void applyRelARM64(uint8_t *Off, uint16_t Type, OutputSection *OS, uint64_t S, uint64_t P) const; // Called if the garbage collector decides to not include this chunk // in a final output. It's supposed to print out a log message to stdout. void printDiscardedMessage() const; // Adds COMDAT associative sections to this COMDAT section. A chunk // and its children are treated as a group by the garbage collector. void addAssociative(SectionChunk *Child); StringRef getDebugName() override; // Returns true if the chunk was not dropped by GC. bool isLive() { return Live; } // Used by the garbage collector. void markLive() { assert(Config->DoGC && "should only mark things live from GC"); assert(!isLive() && "Cannot mark an already live section!"); Live = true; } // True if this is a codeview debug info chunk. These will not be laid out in // the image. Instead they will end up in the PDB, if one is requested. bool isCodeView() const { return SectionName == ".debug" || SectionName.startswith(".debug$"); } // True if this is a DWARF debug info or exception handling chunk. bool isDWARF() const { return SectionName.startswith(".debug_") || SectionName == ".eh_frame"; } // Allow iteration over the bodies of this chunk's relocated symbols. llvm::iterator_range symbols() const { return llvm::make_range(symbol_iterator(File, Relocs.begin()), symbol_iterator(File, Relocs.end())); } // Allow iteration over the associated child chunks for this section. ArrayRef children() const { return AssocChildren; } // A pointer pointing to a replacement for this chunk. // Initially it points to "this" object. If this chunk is merged // with other chunk by ICF, it points to another chunk, // and this chunk is considrered as dead. SectionChunk *Repl; // The CRC of the contents as described in the COFF spec 4.5.5. // Auxiliary Format 5: Section Definitions. Used for ICF. uint32_t Checksum = 0; const coff_section *Header; // The file that this chunk was created from. ObjFile *File; // The COMDAT leader symbol if this is a COMDAT chunk. DefinedRegular *Sym = nullptr; ArrayRef Relocs; private: StringRef SectionName; std::vector AssocChildren; // Used by the garbage collector. bool Live; // Used for ICF (Identical COMDAT Folding) void replace(SectionChunk *Other); uint32_t Class[2] = {0, 0}; }; // This class is used to implement an lld-specific feature (not implemented in // MSVC) that minimizes the output size by finding string literals sharing tail // parts and merging them. // // If string tail merging is enabled and a section is identified as containing a // string literal, it is added to a MergeChunk with an appropriate alignment. // The MergeChunk then tail merges the strings using the StringTableBuilder // class and assigns RVAs and section offsets to each of the member chunks based // on the offsets assigned by the StringTableBuilder. class MergeChunk : public Chunk { public: MergeChunk(uint32_t Alignment); static void addSection(SectionChunk *C); void finalizeContents() override; uint32_t getOutputCharacteristics() const override; StringRef getSectionName() const override { return ".rdata"; } size_t getSize() const override; void writeTo(uint8_t *Buf) const override; static std::map Instances; std::vector Sections; private: llvm::StringTableBuilder Builder; }; // A chunk for common symbols. Common chunks don't have actual data. class CommonChunk : public Chunk { public: CommonChunk(const COFFSymbolRef Sym); size_t getSize() const override { return Sym.getValue(); } bool hasData() const override { return false; } uint32_t getOutputCharacteristics() const override; StringRef getSectionName() const override { return ".bss"; } private: const COFFSymbolRef Sym; }; // A chunk for linker-created strings. class StringChunk : public Chunk { public: explicit StringChunk(StringRef S) : Str(S) {} size_t getSize() const override { return Str.size() + 1; } void writeTo(uint8_t *Buf) const override; private: StringRef Str; }; static const uint8_t ImportThunkX86[] = { 0xff, 0x25, 0x00, 0x00, 0x00, 0x00, // JMP *0x0 }; static const uint8_t ImportThunkARM[] = { 0x40, 0xf2, 0x00, 0x0c, // mov.w ip, #0 0xc0, 0xf2, 0x00, 0x0c, // mov.t ip, #0 0xdc, 0xf8, 0x00, 0xf0, // ldr.w pc, [ip] }; static const uint8_t ImportThunkARM64[] = { 0x10, 0x00, 0x00, 0x90, // adrp x16, #0 0x10, 0x02, 0x40, 0xf9, // ldr x16, [x16] 0x00, 0x02, 0x1f, 0xd6, // br x16 }; // Windows-specific. // A chunk for DLL import jump table entry. In a final output, it's // contents will be a JMP instruction to some __imp_ symbol. class ImportThunkChunkX64 : public Chunk { public: explicit ImportThunkChunkX64(Defined *S); size_t getSize() const override { return sizeof(ImportThunkX86); } void writeTo(uint8_t *Buf) const override; private: Defined *ImpSymbol; }; class ImportThunkChunkX86 : public Chunk { public: explicit ImportThunkChunkX86(Defined *S) : ImpSymbol(S) {} size_t getSize() const override { return sizeof(ImportThunkX86); } void getBaserels(std::vector *Res) override; void writeTo(uint8_t *Buf) const override; private: Defined *ImpSymbol; }; class ImportThunkChunkARM : public Chunk { public: explicit ImportThunkChunkARM(Defined *S) : ImpSymbol(S) {} size_t getSize() const override { return sizeof(ImportThunkARM); } void getBaserels(std::vector *Res) override; void writeTo(uint8_t *Buf) const override; private: Defined *ImpSymbol; }; class ImportThunkChunkARM64 : public Chunk { public: explicit ImportThunkChunkARM64(Defined *S) : ImpSymbol(S) {} size_t getSize() const override { return sizeof(ImportThunkARM64); } void writeTo(uint8_t *Buf) const override; private: Defined *ImpSymbol; }; // Windows-specific. // See comments for DefinedLocalImport class. class LocalImportChunk : public Chunk { public: - explicit LocalImportChunk(Defined *S) : Sym(S) {} + explicit LocalImportChunk(Defined *S) : Sym(S) { + Alignment = Config->is64() ? 8 : 4; + } size_t getSize() const override; void getBaserels(std::vector *Res) override; void writeTo(uint8_t *Buf) const override; private: Defined *Sym; }; // Duplicate RVAs are not allowed in RVA tables, so unique symbols by chunk and // offset into the chunk. Order does not matter as the RVA table will be sorted // later. struct ChunkAndOffset { Chunk *InputChunk; uint32_t Offset; struct DenseMapInfo { static ChunkAndOffset getEmptyKey() { return {llvm::DenseMapInfo::getEmptyKey(), 0}; } static ChunkAndOffset getTombstoneKey() { return {llvm::DenseMapInfo::getTombstoneKey(), 0}; } static unsigned getHashValue(const ChunkAndOffset &CO) { return llvm::DenseMapInfo>::getHashValue( {CO.InputChunk, CO.Offset}); } static bool isEqual(const ChunkAndOffset &LHS, const ChunkAndOffset &RHS) { return LHS.InputChunk == RHS.InputChunk && LHS.Offset == RHS.Offset; } }; }; using SymbolRVASet = llvm::DenseSet; // Table which contains symbol RVAs. Used for /safeseh and /guard:cf. class RVATableChunk : public Chunk { public: explicit RVATableChunk(SymbolRVASet S) : Syms(std::move(S)) {} size_t getSize() const override { return Syms.size() * 4; } void writeTo(uint8_t *Buf) const override; private: SymbolRVASet Syms; }; // Windows-specific. // This class represents a block in .reloc section. // See the PE/COFF spec 5.6 for details. class BaserelChunk : public Chunk { public: BaserelChunk(uint32_t Page, Baserel *Begin, Baserel *End); size_t getSize() const override { return Data.size(); } void writeTo(uint8_t *Buf) const override; private: std::vector Data; }; class Baserel { public: Baserel(uint32_t V, uint8_t Ty) : RVA(V), Type(Ty) {} explicit Baserel(uint32_t V) : Baserel(V, getDefaultType()) {} uint8_t getDefaultType(); uint32_t RVA; uint8_t Type; }; void applyMOV32T(uint8_t *Off, uint32_t V); void applyBranch24T(uint8_t *Off, int32_t V); } // namespace coff } // namespace lld namespace llvm { template <> struct DenseMapInfo : lld::coff::ChunkAndOffset::DenseMapInfo {}; } #endif Index: vendor/lld/dist-release_70/ELF/ScriptParser.cpp =================================================================== --- vendor/lld/dist-release_70/ELF/ScriptParser.cpp (revision 340121) +++ vendor/lld/dist-release_70/ELF/ScriptParser.cpp (revision 340122) @@ -1,1472 +1,1480 @@ //===- ScriptParser.cpp ---------------------------------------------------===// // // The LLVM Linker // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file contains a recursive-descendent parser for linker scripts. // Parsed results are stored to Config and Script global objects. // //===----------------------------------------------------------------------===// #include "ScriptParser.h" #include "Config.h" #include "Driver.h" #include "InputSection.h" #include "LinkerScript.h" #include "OutputSections.h" #include "ScriptLexer.h" #include "Symbols.h" #include "Target.h" #include "lld/Common/Memory.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/StringRef.h" #include "llvm/ADT/StringSet.h" #include "llvm/ADT/StringSwitch.h" #include "llvm/BinaryFormat/ELF.h" #include "llvm/Support/Casting.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/FileSystem.h" #include "llvm/Support/Path.h" #include #include #include using namespace llvm; using namespace llvm::ELF; using namespace llvm::support::endian; using namespace lld; using namespace lld::elf; static bool isUnderSysroot(StringRef Path); namespace { class ScriptParser final : ScriptLexer { public: ScriptParser(MemoryBufferRef MB) : ScriptLexer(MB), IsUnderSysroot(isUnderSysroot(MB.getBufferIdentifier())) {} void readLinkerScript(); void readVersionScript(); void readDynamicList(); void readDefsym(StringRef Name); private: void addFile(StringRef Path); void readAsNeeded(); void readEntry(); void readExtern(); void readGroup(); void readInclude(); void readInput(); void readMemory(); void readOutput(); void readOutputArch(); void readOutputFormat(); void readPhdrs(); void readRegionAlias(); void readSearchDir(); void readSections(); void readVersion(); void readVersionScriptCommand(); SymbolAssignment *readSymbolAssignment(StringRef Name); ByteCommand *readByteCommand(StringRef Tok); uint32_t readFill(); uint32_t parseFill(StringRef Tok); void readSectionAddressType(OutputSection *Cmd); OutputSection *readOverlaySectionDescription(); OutputSection *readOutputSectionDescription(StringRef OutSec); std::vector readOverlay(); std::vector readOutputSectionPhdrs(); InputSectionDescription *readInputSectionDescription(StringRef Tok); StringMatcher readFilePatterns(); std::vector readInputSectionsList(); InputSectionDescription *readInputSectionRules(StringRef FilePattern); unsigned readPhdrType(); SortSectionPolicy readSortKind(); SymbolAssignment *readProvideHidden(bool Provide, bool Hidden); SymbolAssignment *readAssignment(StringRef Tok); void readSort(); Expr readAssert(); Expr readConstant(); Expr getPageSize(); uint64_t readMemoryAssignment(StringRef, StringRef, StringRef); std::pair readMemoryAttributes(); Expr combine(StringRef Op, Expr L, Expr R); Expr readExpr(); Expr readExpr1(Expr Lhs, int MinPrec); StringRef readParenLiteral(); Expr readPrimary(); Expr readTernary(Expr Cond); Expr readParenExpr(); // For parsing version script. std::vector readVersionExtern(); void readAnonymousDeclaration(); void readVersionDeclaration(StringRef VerStr); std::pair, std::vector> readSymbols(); // True if a script being read is in a subdirectory specified by -sysroot. bool IsUnderSysroot; // A set to detect an INCLUDE() cycle. StringSet<> Seen; }; } // namespace static StringRef unquote(StringRef S) { if (S.startswith("\"")) return S.substr(1, S.size() - 2); return S; } static bool isUnderSysroot(StringRef Path) { if (Config->Sysroot == "") return false; for (; !Path.empty(); Path = sys::path::parent_path(Path)) if (sys::fs::equivalent(Config->Sysroot, Path)) return true; return false; } // Some operations only support one non absolute value. Move the // absolute one to the right hand side for convenience. static void moveAbsRight(ExprValue &A, ExprValue &B) { if (A.Sec == nullptr || (A.ForceAbsolute && !B.isAbsolute())) std::swap(A, B); if (!B.isAbsolute()) error(A.Loc + ": at least one side of the expression must be absolute"); } static ExprValue add(ExprValue A, ExprValue B) { moveAbsRight(A, B); return {A.Sec, A.ForceAbsolute, A.getSectionOffset() + B.getValue(), A.Loc}; } static ExprValue sub(ExprValue A, ExprValue B) { // The distance between two symbols in sections is absolute. if (!A.isAbsolute() && !B.isAbsolute()) return A.getValue() - B.getValue(); return {A.Sec, false, A.getSectionOffset() - B.getValue(), A.Loc}; } static ExprValue bitAnd(ExprValue A, ExprValue B) { moveAbsRight(A, B); return {A.Sec, A.ForceAbsolute, (A.getValue() & B.getValue()) - A.getSecAddr(), A.Loc}; } static ExprValue bitOr(ExprValue A, ExprValue B) { moveAbsRight(A, B); return {A.Sec, A.ForceAbsolute, (A.getValue() | B.getValue()) - A.getSecAddr(), A.Loc}; } void ScriptParser::readDynamicList() { Config->HasDynamicList = true; expect("{"); std::vector Locals; std::vector Globals; std::tie(Locals, Globals) = readSymbols(); expect(";"); if (!atEOF()) { setError("EOF expected, but got " + next()); return; } if (!Locals.empty()) { setError("\"local:\" scope not supported in --dynamic-list"); return; } for (SymbolVersion V : Globals) Config->DynamicList.push_back(V); } void ScriptParser::readVersionScript() { readVersionScriptCommand(); if (!atEOF()) setError("EOF expected, but got " + next()); } void ScriptParser::readVersionScriptCommand() { if (consume("{")) { readAnonymousDeclaration(); return; } while (!atEOF() && !errorCount() && peek() != "}") { StringRef VerStr = next(); if (VerStr == "{") { setError("anonymous version definition is used in " "combination with other version definitions"); return; } expect("{"); readVersionDeclaration(VerStr); } } void ScriptParser::readVersion() { expect("{"); readVersionScriptCommand(); expect("}"); } void ScriptParser::readLinkerScript() { while (!atEOF()) { StringRef Tok = next(); if (Tok == ";") continue; if (Tok == "ENTRY") { readEntry(); } else if (Tok == "EXTERN") { readExtern(); } else if (Tok == "GROUP") { readGroup(); } else if (Tok == "INCLUDE") { readInclude(); } else if (Tok == "INPUT") { readInput(); } else if (Tok == "MEMORY") { readMemory(); } else if (Tok == "OUTPUT") { readOutput(); } else if (Tok == "OUTPUT_ARCH") { readOutputArch(); } else if (Tok == "OUTPUT_FORMAT") { readOutputFormat(); } else if (Tok == "PHDRS") { readPhdrs(); } else if (Tok == "REGION_ALIAS") { readRegionAlias(); } else if (Tok == "SEARCH_DIR") { readSearchDir(); } else if (Tok == "SECTIONS") { readSections(); } else if (Tok == "VERSION") { readVersion(); } else if (SymbolAssignment *Cmd = readAssignment(Tok)) { Script->SectionCommands.push_back(Cmd); } else { setError("unknown directive: " + Tok); } } } void ScriptParser::readDefsym(StringRef Name) { Expr E = readExpr(); if (!atEOF()) setError("EOF expected, but got " + next()); SymbolAssignment *Cmd = make(Name, E, getCurrentLocation()); Script->SectionCommands.push_back(Cmd); } void ScriptParser::addFile(StringRef S) { if (IsUnderSysroot && S.startswith("/")) { SmallString<128> PathData; StringRef Path = (Config->Sysroot + S).toStringRef(PathData); if (sys::fs::exists(Path)) { Driver->addFile(Saver.save(Path), /*WithLOption=*/false); return; } } if (S.startswith("/")) { Driver->addFile(S, /*WithLOption=*/false); } else if (S.startswith("=")) { if (Config->Sysroot.empty()) Driver->addFile(S.substr(1), /*WithLOption=*/false); else Driver->addFile(Saver.save(Config->Sysroot + "/" + S.substr(1)), /*WithLOption=*/false); } else if (S.startswith("-l")) { Driver->addLibrary(S.substr(2)); } else if (sys::fs::exists(S)) { Driver->addFile(S, /*WithLOption=*/false); } else { if (Optional Path = findFromSearchPaths(S)) Driver->addFile(Saver.save(*Path), /*WithLOption=*/true); else setError("unable to find " + S); } } void ScriptParser::readAsNeeded() { expect("("); bool Orig = Config->AsNeeded; Config->AsNeeded = true; while (!errorCount() && !consume(")")) addFile(unquote(next())); Config->AsNeeded = Orig; } void ScriptParser::readEntry() { // -e takes predecence over ENTRY(). expect("("); StringRef Tok = next(); if (Config->Entry.empty()) Config->Entry = Tok; expect(")"); } void ScriptParser::readExtern() { expect("("); while (!errorCount() && !consume(")")) Config->Undefined.push_back(next()); } void ScriptParser::readGroup() { bool Orig = InputFile::IsInGroup; InputFile::IsInGroup = true; readInput(); InputFile::IsInGroup = Orig; if (!Orig) ++InputFile::NextGroupId; } void ScriptParser::readInclude() { StringRef Tok = unquote(next()); if (!Seen.insert(Tok).second) { setError("there is a cycle in linker script INCLUDEs"); return; } if (Optional Path = searchScript(Tok)) { if (Optional MB = readFile(*Path)) tokenize(*MB); return; } setError("cannot find linker script " + Tok); } void ScriptParser::readInput() { expect("("); while (!errorCount() && !consume(")")) { if (consume("AS_NEEDED")) readAsNeeded(); else addFile(unquote(next())); } } void ScriptParser::readOutput() { // -o takes predecence over OUTPUT(). expect("("); StringRef Tok = next(); if (Config->OutputFile.empty()) Config->OutputFile = unquote(Tok); expect(")"); } void ScriptParser::readOutputArch() { // OUTPUT_ARCH is ignored for now. expect("("); while (!errorCount() && !consume(")")) skip(); } void ScriptParser::readOutputFormat() { // Error checking only for now. expect("("); skip(); if (consume(")")) return; expect(","); skip(); expect(","); skip(); expect(")"); } void ScriptParser::readPhdrs() { expect("{"); while (!errorCount() && !consume("}")) { PhdrsCommand Cmd; Cmd.Name = next(); Cmd.Type = readPhdrType(); while (!errorCount() && !consume(";")) { if (consume("FILEHDR")) Cmd.HasFilehdr = true; else if (consume("PHDRS")) Cmd.HasPhdrs = true; else if (consume("AT")) Cmd.LMAExpr = readParenExpr(); else if (consume("FLAGS")) Cmd.Flags = readParenExpr()().getValue(); else setError("unexpected header attribute: " + next()); } Script->PhdrsCommands.push_back(Cmd); } } void ScriptParser::readRegionAlias() { expect("("); StringRef Alias = unquote(next()); expect(","); StringRef Name = next(); expect(")"); if (Script->MemoryRegions.count(Alias)) setError("redefinition of memory region '" + Alias + "'"); if (!Script->MemoryRegions.count(Name)) setError("memory region '" + Name + "' is not defined"); Script->MemoryRegions.insert({Alias, Script->MemoryRegions[Name]}); } void ScriptParser::readSearchDir() { expect("("); StringRef Tok = next(); if (!Config->Nostdlib) Config->SearchPaths.push_back(unquote(Tok)); expect(")"); } // This reads an overlay description. Overlays are used to describe output // sections that use the same virtual memory range and normally would trigger // linker's sections sanity check failures. // https://sourceware.org/binutils/docs/ld/Overlay-Description.html#Overlay-Description std::vector ScriptParser::readOverlay() { // VA and LMA expressions are optional, though for simplicity of // implementation we assume they are not. That is what OVERLAY was designed // for first of all: to allow sections with overlapping VAs at different LMAs. Expr AddrExpr = readExpr(); expect(":"); expect("AT"); Expr LMAExpr = readParenExpr(); expect("{"); std::vector V; OutputSection *Prev = nullptr; while (!errorCount() && !consume("}")) { // VA is the same for all sections. The LMAs are consecutive in memory // starting from the base load address specified. OutputSection *OS = readOverlaySectionDescription(); OS->AddrExpr = AddrExpr; if (Prev) OS->LMAExpr = [=] { return Prev->getLMA() + Prev->Size; }; else OS->LMAExpr = LMAExpr; V.push_back(OS); Prev = OS; } // According to the specification, at the end of the overlay, the location // counter should be equal to the overlay base address plus size of the // largest section seen in the overlay. // Here we want to create the Dot assignment command to achieve that. Expr MoveDot = [=] { uint64_t Max = 0; for (BaseCommand *Cmd : V) Max = std::max(Max, cast(Cmd)->Size); return AddrExpr().getValue() + Max; }; V.push_back(make(".", MoveDot, getCurrentLocation())); return V; } void ScriptParser::readSections() { Script->HasSectionsCommand = true; // -no-rosegment is used to avoid placing read only non-executable sections in // their own segment. We do the same if SECTIONS command is present in linker // script. See comment for computeFlags(). Config->SingleRoRx = true; expect("{"); std::vector V; while (!errorCount() && !consume("}")) { StringRef Tok = next(); if (Tok == "OVERLAY") { for (BaseCommand *Cmd : readOverlay()) V.push_back(Cmd); continue; + } else if (Tok == "INCLUDE") { + readInclude(); + continue; } if (BaseCommand *Cmd = readAssignment(Tok)) V.push_back(Cmd); else V.push_back(readOutputSectionDescription(Tok)); } if (!atEOF() && consume("INSERT")) { std::vector *Dest = nullptr; if (consume("AFTER")) Dest = &Script->InsertAfterCommands[next()]; else if (consume("BEFORE")) Dest = &Script->InsertBeforeCommands[next()]; else setError("expected AFTER/BEFORE, but got '" + next() + "'"); if (Dest) Dest->insert(Dest->end(), V.begin(), V.end()); return; } Script->SectionCommands.insert(Script->SectionCommands.end(), V.begin(), V.end()); } static int precedence(StringRef Op) { return StringSwitch(Op) .Cases("*", "/", "%", 8) .Cases("+", "-", 7) .Cases("<<", ">>", 6) .Cases("<", "<=", ">", ">=", "==", "!=", 5) .Case("&", 4) .Case("|", 3) .Case("&&", 2) .Case("||", 1) .Default(-1); } StringMatcher ScriptParser::readFilePatterns() { std::vector V; while (!errorCount() && !consume(")")) V.push_back(next()); return StringMatcher(V); } SortSectionPolicy ScriptParser::readSortKind() { if (consume("SORT") || consume("SORT_BY_NAME")) return SortSectionPolicy::Name; if (consume("SORT_BY_ALIGNMENT")) return SortSectionPolicy::Alignment; if (consume("SORT_BY_INIT_PRIORITY")) return SortSectionPolicy::Priority; if (consume("SORT_NONE")) return SortSectionPolicy::None; return SortSectionPolicy::Default; } // Reads SECTIONS command contents in the following form: // // ::= * // ::= ? // ::= "EXCLUDE_FILE" "(" + ")" // // For example, // // *(.foo EXCLUDE_FILE (a.o) .bar EXCLUDE_FILE (b.o) .baz) // // is parsed as ".foo", ".bar" with "a.o", and ".baz" with "b.o". // The semantics of that is section .foo in any file, section .bar in // any file but a.o, and section .baz in any file but b.o. std::vector ScriptParser::readInputSectionsList() { std::vector Ret; while (!errorCount() && peek() != ")") { StringMatcher ExcludeFilePat; if (consume("EXCLUDE_FILE")) { expect("("); ExcludeFilePat = readFilePatterns(); } std::vector V; while (!errorCount() && peek() != ")" && peek() != "EXCLUDE_FILE") V.push_back(next()); if (!V.empty()) Ret.push_back({std::move(ExcludeFilePat), StringMatcher(V)}); else setError("section pattern is expected"); } return Ret; } // Reads contents of "SECTIONS" directive. That directive contains a // list of glob patterns for input sections. The grammar is as follows. // // ::= // | "(" ")" // | "(" "(" ")" ")" // // ::= "SORT" | "SORT_BY_NAME" | "SORT_BY_ALIGNMENT" // | "SORT_BY_INIT_PRIORITY" | "SORT_NONE" // // is parsed by readInputSectionsList(). InputSectionDescription * ScriptParser::readInputSectionRules(StringRef FilePattern) { auto *Cmd = make(FilePattern); expect("("); while (!errorCount() && !consume(")")) { SortSectionPolicy Outer = readSortKind(); SortSectionPolicy Inner = SortSectionPolicy::Default; std::vector V; if (Outer != SortSectionPolicy::Default) { expect("("); Inner = readSortKind(); if (Inner != SortSectionPolicy::Default) { expect("("); V = readInputSectionsList(); expect(")"); } else { V = readInputSectionsList(); } expect(")"); } else { V = readInputSectionsList(); } for (SectionPattern &Pat : V) { Pat.SortInner = Inner; Pat.SortOuter = Outer; } std::move(V.begin(), V.end(), std::back_inserter(Cmd->SectionPatterns)); } return Cmd; } InputSectionDescription * ScriptParser::readInputSectionDescription(StringRef Tok) { // Input section wildcard can be surrounded by KEEP. // https://sourceware.org/binutils/docs/ld/Input-Section-Keep.html#Input-Section-Keep if (Tok == "KEEP") { expect("("); StringRef FilePattern = next(); InputSectionDescription *Cmd = readInputSectionRules(FilePattern); expect(")"); Script->KeptSections.push_back(Cmd); return Cmd; } return readInputSectionRules(Tok); } void ScriptParser::readSort() { expect("("); expect("CONSTRUCTORS"); expect(")"); } Expr ScriptParser::readAssert() { expect("("); Expr E = readExpr(); expect(","); StringRef Msg = unquote(next()); expect(")"); return [=] { if (!E().getValue()) error(Msg); return Script->getDot(); }; } // Reads a FILL(expr) command. We handle the FILL command as an // alias for =fillexp section attribute, which is different from // what GNU linkers do. // https://sourceware.org/binutils/docs/ld/Output-Section-Data.html uint32_t ScriptParser::readFill() { expect("("); uint32_t V = parseFill(next()); expect(")"); return V; } // Reads an expression and/or the special directive for an output // section definition. Directive is one of following: "(NOLOAD)", // "(COPY)", "(INFO)" or "(OVERLAY)". // // An output section name can be followed by an address expression // and/or directive. This grammar is not LL(1) because "(" can be // interpreted as either the beginning of some expression or beginning // of directive. // // https://sourceware.org/binutils/docs/ld/Output-Section-Address.html // https://sourceware.org/binutils/docs/ld/Output-Section-Type.html void ScriptParser::readSectionAddressType(OutputSection *Cmd) { if (consume("(")) { if (consume("NOLOAD")) { expect(")"); Cmd->Noload = true; return; } if (consume("COPY") || consume("INFO") || consume("OVERLAY")) { expect(")"); Cmd->NonAlloc = true; return; } Cmd->AddrExpr = readExpr(); expect(")"); } else { Cmd->AddrExpr = readExpr(); } if (consume("(")) { expect("NOLOAD"); expect(")"); Cmd->Noload = true; } } static Expr checkAlignment(Expr E, std::string &Loc) { return [=] { uint64_t Alignment = std::max((uint64_t)1, E().getValue()); if (!isPowerOf2_64(Alignment)) { error(Loc + ": alignment must be power of 2"); return (uint64_t)1; // Return a dummy value. } return Alignment; }; } OutputSection *ScriptParser::readOverlaySectionDescription() { OutputSection *Cmd = Script->createOutputSection(next(), getCurrentLocation()); Cmd->InOverlay = true; expect("{"); while (!errorCount() && !consume("}")) Cmd->SectionCommands.push_back(readInputSectionRules(next())); Cmd->Phdrs = readOutputSectionPhdrs(); return Cmd; } OutputSection *ScriptParser::readOutputSectionDescription(StringRef OutSec) { OutputSection *Cmd = Script->createOutputSection(OutSec, getCurrentLocation()); size_t SymbolsReferenced = Script->ReferencedSymbols.size(); if (peek() != ":") readSectionAddressType(Cmd); expect(":"); std::string Location = getCurrentLocation(); if (consume("AT")) Cmd->LMAExpr = readParenExpr(); if (consume("ALIGN")) Cmd->AlignExpr = checkAlignment(readParenExpr(), Location); if (consume("SUBALIGN")) Cmd->SubalignExpr = checkAlignment(readParenExpr(), Location); // Parse constraints. if (consume("ONLY_IF_RO")) Cmd->Constraint = ConstraintKind::ReadOnly; if (consume("ONLY_IF_RW")) Cmd->Constraint = ConstraintKind::ReadWrite; expect("{"); while (!errorCount() && !consume("}")) { StringRef Tok = next(); if (Tok == ";") { // Empty commands are allowed. Do nothing here. } else if (SymbolAssignment *Assign = readAssignment(Tok)) { Cmd->SectionCommands.push_back(Assign); } else if (ByteCommand *Data = readByteCommand(Tok)) { Cmd->SectionCommands.push_back(Data); } else if (Tok == "CONSTRUCTORS") { // CONSTRUCTORS is a keyword to make the linker recognize C++ ctors/dtors // by name. This is for very old file formats such as ECOFF/XCOFF. // For ELF, we should ignore. } else if (Tok == "FILL") { Cmd->Filler = readFill(); } else if (Tok == "SORT") { readSort(); + } else if (Tok == "INCLUDE") { + readInclude(); } else if (peek() == "(") { Cmd->SectionCommands.push_back(readInputSectionDescription(Tok)); } else { setError("unknown command " + Tok); } } if (consume(">")) Cmd->MemoryRegionName = next(); if (consume("AT")) { expect(">"); Cmd->LMARegionName = next(); } if (Cmd->LMAExpr && !Cmd->LMARegionName.empty()) error("section can't have both LMA and a load region"); Cmd->Phdrs = readOutputSectionPhdrs(); if (consume("=")) Cmd->Filler = parseFill(next()); else if (peek().startswith("=")) Cmd->Filler = parseFill(next().drop_front()); // Consume optional comma following output section command. consume(","); if (Script->ReferencedSymbols.size() > SymbolsReferenced) Cmd->ExpressionsUseSymbols = true; return Cmd; } // Parses a given string as a octal/decimal/hexadecimal number and // returns it as a big-endian number. Used for `=`. // https://sourceware.org/binutils/docs/ld/Output-Section-Fill.html // // When reading a hexstring, ld.bfd handles it as a blob of arbitrary // size, while ld.gold always handles it as a 32-bit big-endian number. // We are compatible with ld.gold because it's easier to implement. uint32_t ScriptParser::parseFill(StringRef Tok) { uint32_t V = 0; if (!to_integer(Tok, V)) setError("invalid filler expression: " + Tok); uint32_t Buf; write32be(&Buf, V); return Buf; } SymbolAssignment *ScriptParser::readProvideHidden(bool Provide, bool Hidden) { expect("("); SymbolAssignment *Cmd = readSymbolAssignment(next()); Cmd->Provide = Provide; Cmd->Hidden = Hidden; expect(")"); return Cmd; } SymbolAssignment *ScriptParser::readAssignment(StringRef Tok) { // Assert expression returns Dot, so this is equal to ".=." if (Tok == "ASSERT") return make(".", readAssert(), getCurrentLocation()); size_t OldPos = Pos; SymbolAssignment *Cmd = nullptr; if (peek() == "=" || peek() == "+=") Cmd = readSymbolAssignment(Tok); else if (Tok == "PROVIDE") Cmd = readProvideHidden(true, false); else if (Tok == "HIDDEN") Cmd = readProvideHidden(false, true); else if (Tok == "PROVIDE_HIDDEN") Cmd = readProvideHidden(true, true); if (Cmd) { Cmd->CommandString = Tok.str() + " " + llvm::join(Tokens.begin() + OldPos, Tokens.begin() + Pos, " "); expect(";"); } return Cmd; } SymbolAssignment *ScriptParser::readSymbolAssignment(StringRef Name) { StringRef Op = next(); assert(Op == "=" || Op == "+="); Expr E = readExpr(); if (Op == "+=") { std::string Loc = getCurrentLocation(); E = [=] { return add(Script->getSymbolValue(Name, Loc), E()); }; } return make(Name, E, getCurrentLocation()); } // This is an operator-precedence parser to parse a linker // script expression. Expr ScriptParser::readExpr() { // Our lexer is context-aware. Set the in-expression bit so that // they apply different tokenization rules. bool Orig = InExpr; InExpr = true; Expr E = readExpr1(readPrimary(), 0); InExpr = Orig; return E; } Expr ScriptParser::combine(StringRef Op, Expr L, Expr R) { if (Op == "+") return [=] { return add(L(), R()); }; if (Op == "-") return [=] { return sub(L(), R()); }; if (Op == "*") return [=] { return L().getValue() * R().getValue(); }; if (Op == "/") { std::string Loc = getCurrentLocation(); return [=]() -> uint64_t { if (uint64_t RV = R().getValue()) return L().getValue() / RV; error(Loc + ": division by zero"); return 0; }; } if (Op == "%") { std::string Loc = getCurrentLocation(); return [=]() -> uint64_t { if (uint64_t RV = R().getValue()) return L().getValue() % RV; error(Loc + ": modulo by zero"); return 0; }; } if (Op == "<<") return [=] { return L().getValue() << R().getValue(); }; if (Op == ">>") return [=] { return L().getValue() >> R().getValue(); }; if (Op == "<") return [=] { return L().getValue() < R().getValue(); }; if (Op == ">") return [=] { return L().getValue() > R().getValue(); }; if (Op == ">=") return [=] { return L().getValue() >= R().getValue(); }; if (Op == "<=") return [=] { return L().getValue() <= R().getValue(); }; if (Op == "==") return [=] { return L().getValue() == R().getValue(); }; if (Op == "!=") return [=] { return L().getValue() != R().getValue(); }; if (Op == "||") return [=] { return L().getValue() || R().getValue(); }; if (Op == "&&") return [=] { return L().getValue() && R().getValue(); }; if (Op == "&") return [=] { return bitAnd(L(), R()); }; if (Op == "|") return [=] { return bitOr(L(), R()); }; llvm_unreachable("invalid operator"); } // This is a part of the operator-precedence parser. This function // assumes that the remaining token stream starts with an operator. Expr ScriptParser::readExpr1(Expr Lhs, int MinPrec) { while (!atEOF() && !errorCount()) { // Read an operator and an expression. if (consume("?")) return readTernary(Lhs); StringRef Op1 = peek(); if (precedence(Op1) < MinPrec) break; skip(); Expr Rhs = readPrimary(); // Evaluate the remaining part of the expression first if the // next operator has greater precedence than the previous one. // For example, if we have read "+" and "3", and if the next // operator is "*", then we'll evaluate 3 * ... part first. while (!atEOF()) { StringRef Op2 = peek(); if (precedence(Op2) <= precedence(Op1)) break; Rhs = readExpr1(Rhs, precedence(Op2)); } Lhs = combine(Op1, Lhs, Rhs); } return Lhs; } Expr ScriptParser::getPageSize() { std::string Location = getCurrentLocation(); return [=]() -> uint64_t { if (Target) return Target->PageSize; error(Location + ": unable to calculate page size"); return 4096; // Return a dummy value. }; } Expr ScriptParser::readConstant() { StringRef S = readParenLiteral(); if (S == "COMMONPAGESIZE") return getPageSize(); if (S == "MAXPAGESIZE") return [] { return Config->MaxPageSize; }; setError("unknown constant: " + S); return [] { return 0; }; } // Parses Tok as an integer. It recognizes hexadecimal (prefixed with // "0x" or suffixed with "H") and decimal numbers. Decimal numbers may // have "K" (Ki) or "M" (Mi) suffixes. static Optional parseInt(StringRef Tok) { // Hexadecimal uint64_t Val; if (Tok.startswith_lower("0x")) { if (!to_integer(Tok.substr(2), Val, 16)) return None; return Val; } if (Tok.endswith_lower("H")) { if (!to_integer(Tok.drop_back(), Val, 16)) return None; return Val; } // Decimal if (Tok.endswith_lower("K")) { if (!to_integer(Tok.drop_back(), Val, 10)) return None; return Val * 1024; } if (Tok.endswith_lower("M")) { if (!to_integer(Tok.drop_back(), Val, 10)) return None; return Val * 1024 * 1024; } if (!to_integer(Tok, Val, 10)) return None; return Val; } ByteCommand *ScriptParser::readByteCommand(StringRef Tok) { int Size = StringSwitch(Tok) .Case("BYTE", 1) .Case("SHORT", 2) .Case("LONG", 4) .Case("QUAD", 8) .Default(-1); if (Size == -1) return nullptr; size_t OldPos = Pos; Expr E = readParenExpr(); std::string CommandString = Tok.str() + " " + llvm::join(Tokens.begin() + OldPos, Tokens.begin() + Pos, " "); return make(E, Size, CommandString); } StringRef ScriptParser::readParenLiteral() { expect("("); bool Orig = InExpr; InExpr = false; StringRef Tok = next(); InExpr = Orig; expect(")"); return Tok; } static void checkIfExists(OutputSection *Cmd, StringRef Location) { if (Cmd->Location.empty() && Script->ErrorOnMissingSection) error(Location + ": undefined section " + Cmd->Name); } Expr ScriptParser::readPrimary() { if (peek() == "(") return readParenExpr(); if (consume("~")) { Expr E = readPrimary(); return [=] { return ~E().getValue(); }; } if (consume("!")) { Expr E = readPrimary(); return [=] { return !E().getValue(); }; } if (consume("-")) { Expr E = readPrimary(); return [=] { return -E().getValue(); }; } StringRef Tok = next(); std::string Location = getCurrentLocation(); // Built-in functions are parsed here. // https://sourceware.org/binutils/docs/ld/Builtin-Functions.html. if (Tok == "ABSOLUTE") { Expr Inner = readParenExpr(); return [=] { ExprValue I = Inner(); I.ForceAbsolute = true; return I; }; } if (Tok == "ADDR") { StringRef Name = readParenLiteral(); OutputSection *Sec = Script->getOrCreateOutputSection(Name); return [=]() -> ExprValue { checkIfExists(Sec, Location); return {Sec, false, 0, Location}; }; } if (Tok == "ALIGN") { expect("("); Expr E = readExpr(); if (consume(")")) { E = checkAlignment(E, Location); return [=] { return alignTo(Script->getDot(), E().getValue()); }; } expect(","); Expr E2 = checkAlignment(readExpr(), Location); expect(")"); return [=] { ExprValue V = E(); V.Alignment = E2().getValue(); return V; }; } if (Tok == "ALIGNOF") { StringRef Name = readParenLiteral(); OutputSection *Cmd = Script->getOrCreateOutputSection(Name); return [=] { checkIfExists(Cmd, Location); return Cmd->Alignment; }; } if (Tok == "ASSERT") return readAssert(); if (Tok == "CONSTANT") return readConstant(); if (Tok == "DATA_SEGMENT_ALIGN") { expect("("); Expr E = readExpr(); expect(","); readExpr(); expect(")"); return [=] { return alignTo(Script->getDot(), std::max((uint64_t)1, E().getValue())); }; } if (Tok == "DATA_SEGMENT_END") { expect("("); expect("."); expect(")"); return [] { return Script->getDot(); }; } if (Tok == "DATA_SEGMENT_RELRO_END") { // GNU linkers implements more complicated logic to handle // DATA_SEGMENT_RELRO_END. We instead ignore the arguments and // just align to the next page boundary for simplicity. expect("("); readExpr(); expect(","); readExpr(); expect(")"); Expr E = getPageSize(); return [=] { return alignTo(Script->getDot(), E().getValue()); }; } if (Tok == "DEFINED") { StringRef Name = readParenLiteral(); return [=] { return Symtab->find(Name) ? 1 : 0; }; } if (Tok == "LENGTH") { StringRef Name = readParenLiteral(); if (Script->MemoryRegions.count(Name) == 0) { setError("memory region not defined: " + Name); return [] { return 0; }; } return [=] { return Script->MemoryRegions[Name]->Length; }; } if (Tok == "LOADADDR") { StringRef Name = readParenLiteral(); OutputSection *Cmd = Script->getOrCreateOutputSection(Name); return [=] { checkIfExists(Cmd, Location); return Cmd->getLMA(); }; } if (Tok == "MAX" || Tok == "MIN") { expect("("); Expr A = readExpr(); expect(","); Expr B = readExpr(); expect(")"); if (Tok == "MIN") return [=] { return std::min(A().getValue(), B().getValue()); }; return [=] { return std::max(A().getValue(), B().getValue()); }; } if (Tok == "ORIGIN") { StringRef Name = readParenLiteral(); if (Script->MemoryRegions.count(Name) == 0) { setError("memory region not defined: " + Name); return [] { return 0; }; } return [=] { return Script->MemoryRegions[Name]->Origin; }; } if (Tok == "SEGMENT_START") { expect("("); skip(); expect(","); Expr E = readExpr(); expect(")"); return [=] { return E(); }; } if (Tok == "SIZEOF") { StringRef Name = readParenLiteral(); OutputSection *Cmd = Script->getOrCreateOutputSection(Name); // Linker script does not create an output section if its content is empty. // We want to allow SIZEOF(.foo) where .foo is a section which happened to // be empty. return [=] { return Cmd->Size; }; } if (Tok == "SIZEOF_HEADERS") return [=] { return elf::getHeaderSize(); }; // Tok is the dot. if (Tok == ".") return [=] { return Script->getSymbolValue(Tok, Location); }; // Tok is a literal number. if (Optional Val = parseInt(Tok)) return [=] { return *Val; }; // Tok is a symbol name. if (!isValidCIdentifier(Tok)) setError("malformed number: " + Tok); Script->ReferencedSymbols.push_back(Tok); return [=] { return Script->getSymbolValue(Tok, Location); }; } Expr ScriptParser::readTernary(Expr Cond) { Expr L = readExpr(); expect(":"); Expr R = readExpr(); return [=] { return Cond().getValue() ? L() : R(); }; } Expr ScriptParser::readParenExpr() { expect("("); Expr E = readExpr(); expect(")"); return E; } std::vector ScriptParser::readOutputSectionPhdrs() { std::vector Phdrs; while (!errorCount() && peek().startswith(":")) { StringRef Tok = next(); Phdrs.push_back((Tok.size() == 1) ? next() : Tok.substr(1)); } return Phdrs; } // Read a program header type name. The next token must be a // name of a program header type or a constant (e.g. "0x3"). unsigned ScriptParser::readPhdrType() { StringRef Tok = next(); if (Optional Val = parseInt(Tok)) return *Val; unsigned Ret = StringSwitch(Tok) .Case("PT_NULL", PT_NULL) .Case("PT_LOAD", PT_LOAD) .Case("PT_DYNAMIC", PT_DYNAMIC) .Case("PT_INTERP", PT_INTERP) .Case("PT_NOTE", PT_NOTE) .Case("PT_SHLIB", PT_SHLIB) .Case("PT_PHDR", PT_PHDR) .Case("PT_TLS", PT_TLS) .Case("PT_GNU_EH_FRAME", PT_GNU_EH_FRAME) .Case("PT_GNU_STACK", PT_GNU_STACK) .Case("PT_GNU_RELRO", PT_GNU_RELRO) .Case("PT_OPENBSD_RANDOMIZE", PT_OPENBSD_RANDOMIZE) .Case("PT_OPENBSD_WXNEEDED", PT_OPENBSD_WXNEEDED) .Case("PT_OPENBSD_BOOTDATA", PT_OPENBSD_BOOTDATA) .Default(-1); if (Ret == (unsigned)-1) { setError("invalid program header type: " + Tok); return PT_NULL; } return Ret; } // Reads an anonymous version declaration. void ScriptParser::readAnonymousDeclaration() { std::vector Locals; std::vector Globals; std::tie(Locals, Globals) = readSymbols(); for (SymbolVersion V : Locals) { if (V.Name == "*") Config->DefaultSymbolVersion = VER_NDX_LOCAL; else Config->VersionScriptLocals.push_back(V); } for (SymbolVersion V : Globals) Config->VersionScriptGlobals.push_back(V); expect(";"); } // Reads a non-anonymous version definition, // e.g. "VerStr { global: foo; bar; local: *; };". void ScriptParser::readVersionDeclaration(StringRef VerStr) { // Read a symbol list. std::vector Locals; std::vector Globals; std::tie(Locals, Globals) = readSymbols(); for (SymbolVersion V : Locals) { if (V.Name == "*") Config->DefaultSymbolVersion = VER_NDX_LOCAL; else Config->VersionScriptLocals.push_back(V); } // Create a new version definition and add that to the global symbols. VersionDefinition Ver; Ver.Name = VerStr; Ver.Globals = Globals; // User-defined version number starts from 2 because 0 and 1 are // reserved for VER_NDX_LOCAL and VER_NDX_GLOBAL, respectively. Ver.Id = Config->VersionDefinitions.size() + 2; Config->VersionDefinitions.push_back(Ver); // Each version may have a parent version. For example, "Ver2" // defined as "Ver2 { global: foo; local: *; } Ver1;" has "Ver1" // as a parent. This version hierarchy is, probably against your // instinct, purely for hint; the runtime doesn't care about it // at all. In LLD, we simply ignore it. if (peek() != ";") skip(); expect(";"); } static bool hasWildcard(StringRef S) { return S.find_first_of("?*[") != StringRef::npos; } // Reads a list of symbols, e.g. "{ global: foo; bar; local: *; };". std::pair, std::vector> ScriptParser::readSymbols() { std::vector Locals; std::vector Globals; std::vector *V = &Globals; while (!errorCount()) { if (consume("}")) break; if (consumeLabel("local")) { V = &Locals; continue; } if (consumeLabel("global")) { V = &Globals; continue; } if (consume("extern")) { std::vector Ext = readVersionExtern(); V->insert(V->end(), Ext.begin(), Ext.end()); } else { StringRef Tok = next(); V->push_back({unquote(Tok), false, hasWildcard(Tok)}); } expect(";"); } return {Locals, Globals}; } // Reads an "extern C++" directive, e.g., // "extern "C++" { ns::*; "f(int, double)"; };" // // The last semicolon is optional. E.g. this is OK: // "extern "C++" { ns::*; "f(int, double)" };" std::vector ScriptParser::readVersionExtern() { StringRef Tok = next(); bool IsCXX = Tok == "\"C++\""; if (!IsCXX && Tok != "\"C\"") setError("Unknown language"); expect("{"); std::vector Ret; while (!errorCount() && peek() != "}") { StringRef Tok = next(); bool HasWildcard = !Tok.startswith("\"") && hasWildcard(Tok); Ret.push_back({unquote(Tok), IsCXX, HasWildcard}); if (consume("}")) return Ret; expect(";"); } expect("}"); return Ret; } uint64_t ScriptParser::readMemoryAssignment(StringRef S1, StringRef S2, StringRef S3) { if (!consume(S1) && !consume(S2) && !consume(S3)) { setError("expected one of: " + S1 + ", " + S2 + ", or " + S3); return 0; } expect("="); return readExpr()().getValue(); } // Parse the MEMORY command as specified in: // https://sourceware.org/binutils/docs/ld/MEMORY.html // // MEMORY { name [(attr)] : ORIGIN = origin, LENGTH = len ... } void ScriptParser::readMemory() { expect("{"); while (!errorCount() && !consume("}")) { - StringRef Name = next(); + StringRef Tok = next(); + if (Tok == "INCLUDE") { + readInclude(); + continue; + } uint32_t Flags = 0; uint32_t NegFlags = 0; if (consume("(")) { std::tie(Flags, NegFlags) = readMemoryAttributes(); expect(")"); } expect(":"); uint64_t Origin = readMemoryAssignment("ORIGIN", "org", "o"); expect(","); uint64_t Length = readMemoryAssignment("LENGTH", "len", "l"); // Add the memory region to the region map. - MemoryRegion *MR = - make(Name, Origin, Length, Flags, NegFlags); - if (!Script->MemoryRegions.insert({Name, MR}).second) - setError("region '" + Name + "' already defined"); + MemoryRegion *MR = make(Tok, Origin, Length, Flags, NegFlags); + if (!Script->MemoryRegions.insert({Tok, MR}).second) + setError("region '" + Tok + "' already defined"); } } // This function parses the attributes used to match against section // flags when placing output sections in a memory region. These flags // are only used when an explicit memory region name is not used. std::pair ScriptParser::readMemoryAttributes() { uint32_t Flags = 0; uint32_t NegFlags = 0; bool Invert = false; for (char C : next().lower()) { uint32_t Flag = 0; if (C == '!') Invert = !Invert; else if (C == 'w') Flag = SHF_WRITE; else if (C == 'x') Flag = SHF_EXECINSTR; else if (C == 'a') Flag = SHF_ALLOC; else if (C != 'r') setError("invalid memory region attribute"); if (Invert) NegFlags |= Flag; else Flags |= Flag; } return {Flags, NegFlags}; } void elf::readLinkerScript(MemoryBufferRef MB) { ScriptParser(MB).readLinkerScript(); } void elf::readVersionScript(MemoryBufferRef MB) { ScriptParser(MB).readVersionScript(); } void elf::readDynamicList(MemoryBufferRef MB) { ScriptParser(MB).readDynamicList(); } void elf::readDefsym(StringRef Name, MemoryBufferRef MB) { ScriptParser(MB).readDefsym(Name); } Index: vendor/lld/dist-release_70/ELF/Symbols.cpp =================================================================== --- vendor/lld/dist-release_70/ELF/Symbols.cpp (revision 340121) +++ vendor/lld/dist-release_70/ELF/Symbols.cpp (revision 340122) @@ -1,273 +1,273 @@ //===- Symbols.cpp --------------------------------------------------------===// // // The LLVM Linker // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "Symbols.h" #include "InputFiles.h" #include "InputSection.h" #include "OutputSections.h" #include "SyntheticSections.h" #include "Target.h" #include "Writer.h" #include "lld/Common/ErrorHandler.h" #include "lld/Common/Strings.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Support/Path.h" #include using namespace llvm; using namespace llvm::object; using namespace llvm::ELF; using namespace lld; using namespace lld::elf; Defined *ElfSym::Bss; Defined *ElfSym::Etext1; Defined *ElfSym::Etext2; Defined *ElfSym::Edata1; Defined *ElfSym::Edata2; Defined *ElfSym::End1; Defined *ElfSym::End2; Defined *ElfSym::GlobalOffsetTable; Defined *ElfSym::MipsGp; Defined *ElfSym::MipsGpDisp; Defined *ElfSym::MipsLocalGp; Defined *ElfSym::RelaIpltEnd; static uint64_t getSymVA(const Symbol &Sym, int64_t &Addend) { switch (Sym.kind()) { case Symbol::DefinedKind: { auto &D = cast(Sym); SectionBase *IS = D.Section; // According to the ELF spec reference to a local symbol from outside // the group are not allowed. Unfortunately .eh_frame breaks that rule // and must be treated specially. For now we just replace the symbol with // 0. if (IS == &InputSection::Discarded) return 0; // This is an absolute symbol. if (!IS) return D.Value; IS = IS->Repl; uint64_t Offset = D.Value; // An object in an SHF_MERGE section might be referenced via a // section symbol (as a hack for reducing the number of local // symbols). // Depending on the addend, the reference via a section symbol // refers to a different object in the merge section. // Since the objects in the merge section are not necessarily // contiguous in the output, the addend can thus affect the final // VA in a non-linear way. // To make this work, we incorporate the addend into the section // offset (and zero out the addend for later processing) so that // we find the right object in the section. if (D.isSection()) { Offset += Addend; Addend = 0; } // In the typical case, this is actually very simple and boils // down to adding together 3 numbers: // 1. The address of the output section. // 2. The offset of the input section within the output section. // 3. The offset within the input section (this addition happens // inside InputSection::getOffset). // // If you understand the data structures involved with this next // line (and how they get built), then you have a pretty good // understanding of the linker. uint64_t VA = IS->getVA(Offset); if (D.isTls() && !Config->Relocatable) { if (!Out::TlsPhdr) fatal(toString(D.File) + " has an STT_TLS symbol but doesn't have an SHF_TLS section"); return VA - Out::TlsPhdr->p_vaddr; } return VA; } case Symbol::SharedKind: case Symbol::UndefinedKind: return 0; case Symbol::LazyArchiveKind: case Symbol::LazyObjectKind: llvm_unreachable("lazy symbol reached writer"); } llvm_unreachable("invalid symbol kind"); } uint64_t Symbol::getVA(int64_t Addend) const { uint64_t OutVA = getSymVA(*this, Addend); return OutVA + Addend; } uint64_t Symbol::getGotVA() const { return InX::Got->getVA() + getGotOffset(); } uint64_t Symbol::getGotOffset() const { return GotIndex * Target->GotEntrySize; } uint64_t Symbol::getGotPltVA() const { if (this->IsInIgot) return InX::IgotPlt->getVA() + getGotPltOffset(); return InX::GotPlt->getVA() + getGotPltOffset(); } uint64_t Symbol::getGotPltOffset() const { if (IsInIgot) return PltIndex * Target->GotPltEntrySize; return (PltIndex + Target->GotPltHeaderEntriesNum) * Target->GotPltEntrySize; } uint64_t Symbol::getPltVA() const { if (this->IsInIplt) return InX::Iplt->getVA() + PltIndex * Target->PltEntrySize; return InX::Plt->getVA() + Target->getPltEntryOffset(PltIndex); } uint64_t Symbol::getPltOffset() const { assert(!this->IsInIplt); return Target->getPltEntryOffset(PltIndex); } uint64_t Symbol::getSize() const { if (const auto *DR = dyn_cast(this)) return DR->Size; return cast(this)->Size; } OutputSection *Symbol::getOutputSection() const { if (auto *S = dyn_cast(this)) { if (auto *Sec = S->Section) return Sec->Repl->getOutputSection(); return nullptr; } return nullptr; } // If a symbol name contains '@', the characters after that is // a symbol version name. This function parses that. void Symbol::parseSymbolVersion() { StringRef S = getName(); size_t Pos = S.find('@'); if (Pos == 0 || Pos == StringRef::npos) return; StringRef Verstr = S.substr(Pos + 1); if (Verstr.empty()) return; // Truncate the symbol name so that it doesn't include the version string. NameSize = Pos; // If this is not in this DSO, it is not a definition. if (!isDefined()) return; // '@@' in a symbol name means the default version. // It is usually the most recent one. bool IsDefault = (Verstr[0] == '@'); if (IsDefault) Verstr = Verstr.substr(1); for (VersionDefinition &Ver : Config->VersionDefinitions) { if (Ver.Name != Verstr) continue; if (IsDefault) VersionId = Ver.Id; else VersionId = Ver.Id | VERSYM_HIDDEN; return; } // It is an error if the specified version is not defined. // Usually version script is not provided when linking executable, // but we may still want to override a versioned symbol from DSO, // so we do not report error in this case. We also do not error // if the symbol has a local version as it won't be in the dynamic // symbol table. if (Config->Shared && VersionId != VER_NDX_LOCAL) error(toString(File) + ": symbol " + S + " has undefined version " + Verstr); } InputFile *LazyArchive::fetch() { return cast(File)->fetch(Sym); } uint8_t Symbol::computeBinding() const { if (Config->Relocatable) return Binding; if (Visibility != STV_DEFAULT && Visibility != STV_PROTECTED) return STB_LOCAL; - if (VersionId == VER_NDX_LOCAL && isDefined()) + if (VersionId == VER_NDX_LOCAL && isDefined() && !IsPreemptible) return STB_LOCAL; if (!Config->GnuUnique && Binding == STB_GNU_UNIQUE) return STB_GLOBAL; return Binding; } bool Symbol::includeInDynsym() const { if (!Config->HasDynSymTab) return false; if (computeBinding() == STB_LOCAL) return false; if (!isDefined()) return true; return ExportDynamic; } // Print out a log message for --trace-symbol. void elf::printTraceSymbol(Symbol *Sym) { std::string S; if (Sym->isUndefined()) S = ": reference to "; else if (Sym->isLazy()) S = ": lazy definition of "; else if (Sym->isShared()) S = ": shared definition of "; else if (dyn_cast_or_null(cast(Sym)->Section)) S = ": common definition of "; else S = ": definition of "; message(toString(Sym->File) + S + Sym->getName()); } void elf::warnUnorderableSymbol(const Symbol *Sym) { if (!Config->WarnSymbolOrdering) return; const InputFile *File = Sym->File; auto *D = dyn_cast(Sym); auto Warn = [&](StringRef S) { warn(toString(File) + S + Sym->getName()); }; if (Sym->isUndefined()) Warn(": unable to order undefined symbol: "); else if (Sym->isShared()) Warn(": unable to order shared symbol: "); else if (D && !D->Section) Warn(": unable to order absolute symbol: "); else if (D && isa(D->Section)) Warn(": unable to order synthetic symbol: "); else if (D && !D->Section->Repl->Live) Warn(": unable to order discarded symbol: "); } // Returns a symbol for an error message. std::string lld::toString(const Symbol &B) { if (Config->Demangle) if (Optional S = demangleItanium(B.getName())) return *S; return B.getName(); } Index: vendor/lld/dist-release_70/ELF/Writer.cpp =================================================================== --- vendor/lld/dist-release_70/ELF/Writer.cpp (revision 340121) +++ vendor/lld/dist-release_70/ELF/Writer.cpp (revision 340122) @@ -1,2406 +1,2406 @@ //===- Writer.cpp ---------------------------------------------------------===// // // The LLVM Linker // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "Writer.h" #include "AArch64ErrataFix.h" #include "CallGraphSort.h" #include "Config.h" #include "Filesystem.h" #include "LinkerScript.h" #include "MapFile.h" #include "OutputSections.h" #include "Relocations.h" #include "SymbolTable.h" #include "Symbols.h" #include "SyntheticSections.h" #include "Target.h" #include "lld/Common/Memory.h" #include "lld/Common/Strings.h" #include "lld/Common/Threads.h" #include "llvm/ADT/StringMap.h" #include "llvm/ADT/StringSwitch.h" #include using namespace llvm; using namespace llvm::ELF; using namespace llvm::object; using namespace llvm::support; using namespace llvm::support::endian; using namespace lld; using namespace lld::elf; namespace { // The writer writes a SymbolTable result to a file. template class Writer { public: Writer() : Buffer(errorHandler().OutputBuffer) {} typedef typename ELFT::Shdr Elf_Shdr; typedef typename ELFT::Ehdr Elf_Ehdr; typedef typename ELFT::Phdr Elf_Phdr; void run(); private: void copyLocalSymbols(); void addSectionSymbols(); void forEachRelSec(llvm::function_ref Fn); void sortSections(); void resolveShfLinkOrder(); void sortInputSections(); void finalizeSections(); void setReservedSymbolSections(); std::vector createPhdrs(); void removeEmptyPTLoad(); void addPtArmExid(std::vector &Phdrs); void assignFileOffsets(); void assignFileOffsetsBinary(); void setPhdrs(); void checkSections(); void fixSectionAlignments(); void openFile(); void writeTrapInstr(); void writeHeader(); void writeSections(); void writeSectionsBinary(); void writeBuildId(); std::unique_ptr &Buffer; void addRelIpltSymbols(); void addStartEndSymbols(); void addStartStopSymbols(OutputSection *Sec); uint64_t getEntryAddr(); std::vector Phdrs; uint64_t FileSize; uint64_t SectionHeaderOff; }; } // anonymous namespace static bool isSectionPrefix(StringRef Prefix, StringRef Name) { return Name.startswith(Prefix) || Name == Prefix.drop_back(); } StringRef elf::getOutputSectionName(const InputSectionBase *S) { if (Config->Relocatable) return S->Name; // This is for --emit-relocs. If .text.foo is emitted as .text.bar, we want // to emit .rela.text.foo as .rela.text.bar for consistency (this is not // technically required, but not doing it is odd). This code guarantees that. if (auto *IS = dyn_cast(S)) { if (InputSectionBase *Rel = IS->getRelocatedSection()) { OutputSection *Out = Rel->getOutputSection(); if (S->Type == SHT_RELA) return Saver.save(".rela" + Out->Name); return Saver.save(".rel" + Out->Name); } } // This check is for -z keep-text-section-prefix. This option separates text // sections with prefix ".text.hot", ".text.unlikely", ".text.startup" or // ".text.exit". // When enabled, this allows identifying the hot code region (.text.hot) in // the final binary which can be selectively mapped to huge pages or mlocked, // for instance. if (Config->ZKeepTextSectionPrefix) for (StringRef V : {".text.hot.", ".text.unlikely.", ".text.startup.", ".text.exit."}) { if (isSectionPrefix(V, S->Name)) return V.drop_back(); } for (StringRef V : {".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.rel.ro.", ".bss.", ".init_array.", ".fini_array.", ".ctors.", ".dtors.", ".tbss.", ".gcc_except_table.", ".tdata.", ".ARM.exidx.", ".ARM.extab."}) { if (isSectionPrefix(V, S->Name)) return V.drop_back(); } // CommonSection is identified as "COMMON" in linker scripts. // By default, it should go to .bss section. if (S->Name == "COMMON") return ".bss"; return S->Name; } static bool needsInterpSection() { return !SharedFiles.empty() && !Config->DynamicLinker.empty() && Script->needsInterpSection(); } template void elf::writeResult() { Writer().run(); } template void Writer::removeEmptyPTLoad() { llvm::erase_if(Phdrs, [&](const PhdrEntry *P) { if (P->p_type != PT_LOAD) return false; if (!P->FirstSec) return true; uint64_t Size = P->LastSec->Addr + P->LastSec->Size - P->FirstSec->Addr; return Size == 0; }); } template static void combineEhFrameSections() { for (InputSectionBase *&S : InputSections) { EhInputSection *ES = dyn_cast(S); if (!ES || !ES->Live) continue; InX::EhFrame->addSection(ES); S = nullptr; } std::vector &V = InputSections; V.erase(std::remove(V.begin(), V.end(), nullptr), V.end()); } static Defined *addOptionalRegular(StringRef Name, SectionBase *Sec, uint64_t Val, uint8_t StOther = STV_HIDDEN, uint8_t Binding = STB_GLOBAL) { Symbol *S = Symtab->find(Name); if (!S || S->isDefined()) return nullptr; Symbol *Sym = Symtab->addRegular(Name, StOther, STT_NOTYPE, Val, /*Size=*/0, Binding, Sec, /*File=*/nullptr); return cast(Sym); } // The linker is expected to define some symbols depending on // the linking result. This function defines such symbols. void elf::addReservedSymbols() { if (Config->EMachine == EM_MIPS) { // Define _gp for MIPS. st_value of _gp symbol will be updated by Writer // so that it points to an absolute address which by default is relative // to GOT. Default offset is 0x7ff0. // See "Global Data Symbols" in Chapter 6 in the following document: // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf ElfSym::MipsGp = Symtab->addAbsolute("_gp", STV_HIDDEN, STB_GLOBAL); // On MIPS O32 ABI, _gp_disp is a magic symbol designates offset between // start of function and 'gp' pointer into GOT. if (Symtab->find("_gp_disp")) ElfSym::MipsGpDisp = Symtab->addAbsolute("_gp_disp", STV_HIDDEN, STB_GLOBAL); // The __gnu_local_gp is a magic symbol equal to the current value of 'gp' // pointer. This symbol is used in the code generated by .cpload pseudo-op // in case of using -mno-shared option. // https://sourceware.org/ml/binutils/2004-12/msg00094.html if (Symtab->find("__gnu_local_gp")) ElfSym::MipsLocalGp = Symtab->addAbsolute("__gnu_local_gp", STV_HIDDEN, STB_GLOBAL); } // The Power Architecture 64-bit v2 ABI defines a TableOfContents (TOC) which // combines the typical ELF GOT with the small data sections. It commonly // includes .got .toc .sdata .sbss. The .TOC. symbol replaces both // _GLOBAL_OFFSET_TABLE_ and _SDA_BASE_ from the 32-bit ABI. It is used to // represent the TOC base which is offset by 0x8000 bytes from the start of // the .got section. ElfSym::GlobalOffsetTable = addOptionalRegular( (Config->EMachine == EM_PPC64) ? ".TOC." : "_GLOBAL_OFFSET_TABLE_", Out::ElfHeader, Target->GotBaseSymOff); // __ehdr_start is the location of ELF file headers. Note that we define // this symbol unconditionally even when using a linker script, which // differs from the behavior implemented by GNU linker which only define // this symbol if ELF headers are in the memory mapped segment. addOptionalRegular("__ehdr_start", Out::ElfHeader, 0, STV_HIDDEN); // __executable_start is not documented, but the expectation of at // least the Android libc is that it points to the ELF header. addOptionalRegular("__executable_start", Out::ElfHeader, 0, STV_HIDDEN); // __dso_handle symbol is passed to cxa_finalize as a marker to identify // each DSO. The address of the symbol doesn't matter as long as they are // different in different DSOs, so we chose the start address of the DSO. addOptionalRegular("__dso_handle", Out::ElfHeader, 0, STV_HIDDEN); // If linker script do layout we do not need to create any standart symbols. if (Script->HasSectionsCommand) return; auto Add = [](StringRef S, int64_t Pos) { return addOptionalRegular(S, Out::ElfHeader, Pos, STV_DEFAULT); }; ElfSym::Bss = Add("__bss_start", 0); ElfSym::End1 = Add("end", -1); ElfSym::End2 = Add("_end", -1); ElfSym::Etext1 = Add("etext", -1); ElfSym::Etext2 = Add("_etext", -1); ElfSym::Edata1 = Add("edata", -1); ElfSym::Edata2 = Add("_edata", -1); } static OutputSection *findSection(StringRef Name) { for (BaseCommand *Base : Script->SectionCommands) if (auto *Sec = dyn_cast(Base)) if (Sec->Name == Name) return Sec; return nullptr; } // Initialize Out members. template static void createSyntheticSections() { // Initialize all pointers with NULL. This is needed because // you can call lld::elf::main more than once as a library. memset(&Out::First, 0, sizeof(Out)); auto Add = [](InputSectionBase *Sec) { InputSections.push_back(Sec); }; InX::DynStrTab = make(".dynstr", true); InX::Dynamic = make>(); if (Config->AndroidPackDynRelocs) { InX::RelaDyn = make>( Config->IsRela ? ".rela.dyn" : ".rel.dyn"); } else { InX::RelaDyn = make>( Config->IsRela ? ".rela.dyn" : ".rel.dyn", Config->ZCombreloc); } InX::ShStrTab = make(".shstrtab", false); Out::ProgramHeaders = make("", 0, SHF_ALLOC); Out::ProgramHeaders->Alignment = Config->Wordsize; if (needsInterpSection()) { InX::Interp = createInterpSection(); Add(InX::Interp); } else { InX::Interp = nullptr; } if (Config->Strip != StripPolicy::All) { InX::StrTab = make(".strtab", false); InX::SymTab = make>(*InX::StrTab); InX::SymTabShndx = make(); } if (Config->BuildId != BuildIdKind::None) { InX::BuildId = make(); Add(InX::BuildId); } InX::Bss = make(".bss", 0, 1); Add(InX::Bss); // If there is a SECTIONS command and a .data.rel.ro section name use name // .data.rel.ro.bss so that we match in the .data.rel.ro output section. // This makes sure our relro is contiguous. bool HasDataRelRo = Script->HasSectionsCommand && findSection(".data.rel.ro"); InX::BssRelRo = make(HasDataRelRo ? ".data.rel.ro.bss" : ".bss.rel.ro", 0, 1); Add(InX::BssRelRo); // Add MIPS-specific sections. if (Config->EMachine == EM_MIPS) { if (!Config->Shared && Config->HasDynSymTab) { InX::MipsRldMap = make(); Add(InX::MipsRldMap); } if (auto *Sec = MipsAbiFlagsSection::create()) Add(Sec); if (auto *Sec = MipsOptionsSection::create()) Add(Sec); if (auto *Sec = MipsReginfoSection::create()) Add(Sec); } if (Config->HasDynSymTab) { InX::DynSymTab = make>(*InX::DynStrTab); Add(InX::DynSymTab); In::VerSym = make>(); Add(In::VerSym); if (!Config->VersionDefinitions.empty()) { In::VerDef = make>(); Add(In::VerDef); } In::VerNeed = make>(); Add(In::VerNeed); if (Config->GnuHash) { InX::GnuHashTab = make(); Add(InX::GnuHashTab); } if (Config->SysvHash) { InX::HashTab = make(); Add(InX::HashTab); } Add(InX::Dynamic); Add(InX::DynStrTab); Add(InX::RelaDyn); } if (Config->RelrPackDynRelocs) { InX::RelrDyn = make>(); Add(InX::RelrDyn); } // Add .got. MIPS' .got is so different from the other archs, // it has its own class. if (Config->EMachine == EM_MIPS) { InX::MipsGot = make(); Add(InX::MipsGot); } else { InX::Got = make(); Add(InX::Got); } InX::GotPlt = make(); Add(InX::GotPlt); InX::IgotPlt = make(); Add(InX::IgotPlt); if (Config->GdbIndex) { InX::GdbIndex = GdbIndexSection::create(); Add(InX::GdbIndex); } // We always need to add rel[a].plt to output if it has entries. // Even for static linking it can contain R_[*]_IRELATIVE relocations. InX::RelaPlt = make>( Config->IsRela ? ".rela.plt" : ".rel.plt", false /*Sort*/); Add(InX::RelaPlt); // The RelaIplt immediately follows .rel.plt (.rel.dyn for ARM) to ensure // that the IRelative relocations are processed last by the dynamic loader. // We cannot place the iplt section in .rel.dyn when Android relocation // packing is enabled because that would cause a section type mismatch. // However, because the Android dynamic loader reads .rel.plt after .rel.dyn, // we can get the desired behaviour by placing the iplt section in .rel.plt. InX::RelaIplt = make>( (Config->EMachine == EM_ARM && !Config->AndroidPackDynRelocs) ? ".rel.dyn" : InX::RelaPlt->Name, false /*Sort*/); Add(InX::RelaIplt); InX::Plt = make(false); Add(InX::Plt); InX::Iplt = make(true); Add(InX::Iplt); if (!Config->Relocatable) { if (Config->EhFrameHdr) { InX::EhFrameHdr = make(); Add(InX::EhFrameHdr); } InX::EhFrame = make(); Add(InX::EhFrame); } if (InX::SymTab) Add(InX::SymTab); if (InX::SymTabShndx) Add(InX::SymTabShndx); Add(InX::ShStrTab); if (InX::StrTab) Add(InX::StrTab); if (Config->EMachine == EM_ARM && !Config->Relocatable) // Add a sentinel to terminate .ARM.exidx. It helps an unwinder // to find the exact address range of the last entry. Add(make()); } // The main function of the writer. template void Writer::run() { // Create linker-synthesized sections such as .got or .plt. // Such sections are of type input section. createSyntheticSections(); if (!Config->Relocatable) combineEhFrameSections(); // We want to process linker script commands. When SECTIONS command // is given we let it create sections. Script->processSectionCommands(); // Linker scripts controls how input sections are assigned to output sections. // Input sections that were not handled by scripts are called "orphans", and // they are assigned to output sections by the default rule. Process that. Script->addOrphanSections(); if (Config->Discard != DiscardPolicy::All) copyLocalSymbols(); if (Config->CopyRelocs) addSectionSymbols(); // Now that we have a complete set of output sections. This function // completes section contents. For example, we need to add strings // to the string table, and add entries to .got and .plt. // finalizeSections does that. finalizeSections(); if (errorCount()) return; Script->assignAddresses(); // If -compressed-debug-sections is specified, we need to compress // .debug_* sections. Do it right now because it changes the size of // output sections. for (OutputSection *Sec : OutputSections) Sec->maybeCompress(); Script->allocateHeaders(Phdrs); // Remove empty PT_LOAD to avoid causing the dynamic linker to try to mmap a // 0 sized region. This has to be done late since only after assignAddresses // we know the size of the sections. removeEmptyPTLoad(); if (!Config->OFormatBinary) assignFileOffsets(); else assignFileOffsetsBinary(); setPhdrs(); if (Config->Relocatable) { for (OutputSection *Sec : OutputSections) Sec->Addr = 0; } if (Config->CheckSections) checkSections(); // It does not make sense try to open the file if we have error already. if (errorCount()) return; // Write the result down to a file. openFile(); if (errorCount()) return; if (!Config->OFormatBinary) { writeTrapInstr(); writeHeader(); writeSections(); } else { writeSectionsBinary(); } // Backfill .note.gnu.build-id section content. This is done at last // because the content is usually a hash value of the entire output file. writeBuildId(); if (errorCount()) return; // Handle -Map and -cref options. writeMapFile(); writeCrossReferenceTable(); if (errorCount()) return; if (auto E = Buffer->commit()) error("failed to write to the output file: " + toString(std::move(E))); } static bool shouldKeepInSymtab(SectionBase *Sec, StringRef SymName, const Symbol &B) { if (B.isSection()) return false; if (Config->Discard == DiscardPolicy::None) return true; // In ELF assembly .L symbols are normally discarded by the assembler. // If the assembler fails to do so, the linker discards them if // * --discard-locals is used. // * The symbol is in a SHF_MERGE section, which is normally the reason for // the assembler keeping the .L symbol. if (!SymName.startswith(".L") && !SymName.empty()) return true; if (Config->Discard == DiscardPolicy::Locals) return false; return !Sec || !(Sec->Flags & SHF_MERGE); } static bool includeInSymtab(const Symbol &B) { if (!B.isLocal() && !B.IsUsedInRegularObj) return false; if (auto *D = dyn_cast(&B)) { // Always include absolute symbols. SectionBase *Sec = D->Section; if (!Sec) return true; Sec = Sec->Repl; // Exclude symbols pointing to garbage-collected sections. if (isa(Sec) && !Sec->Live) return false; if (auto *S = dyn_cast(Sec)) if (!S->getSectionPiece(D->Value)->Live) return false; return true; } return B.Used; } // Local symbols are not in the linker's symbol table. This function scans // each object file's symbol table to copy local symbols to the output. template void Writer::copyLocalSymbols() { if (!InX::SymTab) return; for (InputFile *File : ObjectFiles) { ObjFile *F = cast>(File); for (Symbol *B : F->getLocalSymbols()) { if (!B->isLocal()) fatal(toString(F) + ": broken object: getLocalSymbols returns a non-local symbol"); auto *DR = dyn_cast(B); // No reason to keep local undefined symbol in symtab. if (!DR) continue; if (!includeInSymtab(*B)) continue; SectionBase *Sec = DR->Section; if (!shouldKeepInSymtab(Sec, B->getName(), *B)) continue; InX::SymTab->addSymbol(B); } } } template void Writer::addSectionSymbols() { // Create a section symbol for each output section so that we can represent // relocations that point to the section. If we know that no relocation is // referring to a section (that happens if the section is a synthetic one), we // don't create a section symbol for that section. for (BaseCommand *Base : Script->SectionCommands) { auto *Sec = dyn_cast(Base); if (!Sec) continue; auto I = llvm::find_if(Sec->SectionCommands, [](BaseCommand *Base) { if (auto *ISD = dyn_cast(Base)) return !ISD->Sections.empty(); return false; }); if (I == Sec->SectionCommands.end()) continue; InputSection *IS = cast(*I)->Sections[0]; // Relocations are not using REL[A] section symbols. if (IS->Type == SHT_REL || IS->Type == SHT_RELA) continue; // Unlike other synthetic sections, mergeable output sections contain data // copied from input sections, and there may be a relocation pointing to its // contents if -r or -emit-reloc are given. if (isa(IS) && !(IS->Flags & SHF_MERGE)) continue; auto *Sym = make(IS->File, "", STB_LOCAL, /*StOther=*/0, STT_SECTION, /*Value=*/0, /*Size=*/0, IS); InX::SymTab->addSymbol(Sym); } } // Today's loaders have a feature to make segments read-only after // processing dynamic relocations to enhance security. PT_GNU_RELRO // is defined for that. // // This function returns true if a section needs to be put into a // PT_GNU_RELRO segment. static bool isRelroSection(const OutputSection *Sec) { if (!Config->ZRelro) return false; uint64_t Flags = Sec->Flags; // Non-allocatable or non-writable sections don't need RELRO because // they are not writable or not even mapped to memory in the first place. // RELRO is for sections that are essentially read-only but need to // be writable only at process startup to allow dynamic linker to // apply relocations. if (!(Flags & SHF_ALLOC) || !(Flags & SHF_WRITE)) return false; // Once initialized, TLS data segments are used as data templates // for a thread-local storage. For each new thread, runtime // allocates memory for a TLS and copy templates there. No thread // are supposed to use templates directly. Thus, it can be in RELRO. if (Flags & SHF_TLS) return true; // .init_array, .preinit_array and .fini_array contain pointers to // functions that are executed on process startup or exit. These // pointers are set by the static linker, and they are not expected // to change at runtime. But if you are an attacker, you could do // interesting things by manipulating pointers in .fini_array, for // example. So they are put into RELRO. uint32_t Type = Sec->Type; if (Type == SHT_INIT_ARRAY || Type == SHT_FINI_ARRAY || Type == SHT_PREINIT_ARRAY) return true; // .got contains pointers to external symbols. They are resolved by // the dynamic linker when a module is loaded into memory, and after // that they are not expected to change. So, it can be in RELRO. if (InX::Got && Sec == InX::Got->getParent()) return true; if (Sec->Name.equals(".toc")) return true; // .got.plt contains pointers to external function symbols. They are // by default resolved lazily, so we usually cannot put it into RELRO. // However, if "-z now" is given, the lazy symbol resolution is // disabled, which enables us to put it into RELRO. if (Sec == InX::GotPlt->getParent()) return Config->ZNow; // .dynamic section contains data for the dynamic linker, and // there's no need to write to it at runtime, so it's better to put // it into RELRO. if (Sec == InX::Dynamic->getParent()) return true; // Sections with some special names are put into RELRO. This is a // bit unfortunate because section names shouldn't be significant in // ELF in spirit. But in reality many linker features depend on // magic section names. StringRef S = Sec->Name; return S == ".data.rel.ro" || S == ".bss.rel.ro" || S == ".ctors" || S == ".dtors" || S == ".jcr" || S == ".eh_frame" || S == ".openbsd.randomdata"; } // We compute a rank for each section. The rank indicates where the // section should be placed in the file. Instead of using simple // numbers (0,1,2...), we use a series of flags. One for each decision // point when placing the section. // Using flags has two key properties: // * It is easy to check if a give branch was taken. // * It is easy two see how similar two ranks are (see getRankProximity). enum RankFlags { RF_NOT_ADDR_SET = 1 << 18, RF_NOT_INTERP = 1 << 17, RF_NOT_ALLOC = 1 << 16, RF_WRITE = 1 << 15, RF_EXEC_WRITE = 1 << 14, RF_EXEC = 1 << 13, RF_RODATA = 1 << 12, RF_NON_TLS_BSS = 1 << 11, RF_NON_TLS_BSS_RO = 1 << 10, RF_NOT_TLS = 1 << 9, RF_BSS = 1 << 8, RF_NOTE = 1 << 7, RF_PPC_NOT_TOCBSS = 1 << 6, RF_PPC_TOCL = 1 << 5, RF_PPC_TOC = 1 << 4, RF_PPC_GOT = 1 << 3, RF_PPC_BRANCH_LT = 1 << 2, RF_MIPS_GPREL = 1 << 1, RF_MIPS_NOT_GOT = 1 << 0 }; static unsigned getSectionRank(const OutputSection *Sec) { unsigned Rank = 0; // We want to put section specified by -T option first, so we // can start assigning VA starting from them later. if (Config->SectionStartMap.count(Sec->Name)) return Rank; Rank |= RF_NOT_ADDR_SET; // Put .interp first because some loaders want to see that section // on the first page of the executable file when loaded into memory. if (Sec->Name == ".interp") return Rank; Rank |= RF_NOT_INTERP; // Allocatable sections go first to reduce the total PT_LOAD size and // so debug info doesn't change addresses in actual code. if (!(Sec->Flags & SHF_ALLOC)) return Rank | RF_NOT_ALLOC; // Sort sections based on their access permission in the following // order: R, RX, RWX, RW. This order is based on the following // considerations: // * Read-only sections come first such that they go in the // PT_LOAD covering the program headers at the start of the file. // * Read-only, executable sections come next. // * Writable, executable sections follow such that .plt on // architectures where it needs to be writable will be placed // between .text and .data. // * Writable sections come last, such that .bss lands at the very // end of the last PT_LOAD. bool IsExec = Sec->Flags & SHF_EXECINSTR; bool IsWrite = Sec->Flags & SHF_WRITE; if (IsExec) { if (IsWrite) Rank |= RF_EXEC_WRITE; else Rank |= RF_EXEC; } else if (IsWrite) { Rank |= RF_WRITE; } else if (Sec->Type == SHT_PROGBITS) { // Make non-executable and non-writable PROGBITS sections (e.g .rodata // .eh_frame) closer to .text. They likely contain PC or GOT relative // relocations and there could be relocation overflow if other huge sections // (.dynstr .dynsym) were placed in between. Rank |= RF_RODATA; } // If we got here we know that both A and B are in the same PT_LOAD. bool IsTls = Sec->Flags & SHF_TLS; bool IsNoBits = Sec->Type == SHT_NOBITS; // The first requirement we have is to put (non-TLS) nobits sections last. The // reason is that the only thing the dynamic linker will see about them is a // p_memsz that is larger than p_filesz. Seeing that it zeros the end of the // PT_LOAD, so that has to correspond to the nobits sections. bool IsNonTlsNoBits = IsNoBits && !IsTls; if (IsNonTlsNoBits) Rank |= RF_NON_TLS_BSS; // We place nobits RelRo sections before plain r/w ones, and non-nobits RelRo // sections after r/w ones, so that the RelRo sections are contiguous. bool IsRelRo = isRelroSection(Sec); if (IsNonTlsNoBits && !IsRelRo) Rank |= RF_NON_TLS_BSS_RO; if (!IsNonTlsNoBits && IsRelRo) Rank |= RF_NON_TLS_BSS_RO; // The TLS initialization block needs to be a single contiguous block in a R/W // PT_LOAD, so stick TLS sections directly before the other RelRo R/W // sections. The TLS NOBITS sections are placed here as they don't take up // virtual address space in the PT_LOAD. if (!IsTls) Rank |= RF_NOT_TLS; // Within the TLS initialization block, the non-nobits sections need to appear // first. if (IsNoBits) Rank |= RF_BSS; // We create a NOTE segment for contiguous .note sections, so make // them contigous if there are more than one .note section with the // same attributes. if (Sec->Type == SHT_NOTE) Rank |= RF_NOTE; // Some architectures have additional ordering restrictions for sections // within the same PT_LOAD. if (Config->EMachine == EM_PPC64) { // PPC64 has a number of special SHT_PROGBITS+SHF_ALLOC+SHF_WRITE sections // that we would like to make sure appear is a specific order to maximize // their coverage by a single signed 16-bit offset from the TOC base // pointer. Conversely, the special .tocbss section should be first among // all SHT_NOBITS sections. This will put it next to the loaded special // PPC64 sections (and, thus, within reach of the TOC base pointer). StringRef Name = Sec->Name; if (Name != ".tocbss") Rank |= RF_PPC_NOT_TOCBSS; if (Name == ".toc1") Rank |= RF_PPC_TOCL; if (Name == ".toc") Rank |= RF_PPC_TOC; if (Name == ".got") Rank |= RF_PPC_GOT; if (Name == ".branch_lt") Rank |= RF_PPC_BRANCH_LT; } if (Config->EMachine == EM_MIPS) { // All sections with SHF_MIPS_GPREL flag should be grouped together // because data in these sections is addressable with a gp relative address. if (Sec->Flags & SHF_MIPS_GPREL) Rank |= RF_MIPS_GPREL; if (Sec->Name != ".got") Rank |= RF_MIPS_NOT_GOT; } return Rank; } static bool compareSections(const BaseCommand *ACmd, const BaseCommand *BCmd) { const OutputSection *A = cast(ACmd); const OutputSection *B = cast(BCmd); if (A->SortRank != B->SortRank) return A->SortRank < B->SortRank; if (!(A->SortRank & RF_NOT_ADDR_SET)) return Config->SectionStartMap.lookup(A->Name) < Config->SectionStartMap.lookup(B->Name); return false; } void PhdrEntry::add(OutputSection *Sec) { LastSec = Sec; if (!FirstSec) FirstSec = Sec; p_align = std::max(p_align, Sec->Alignment); if (p_type == PT_LOAD) Sec->PtLoad = this; } // The beginning and the ending of .rel[a].plt section are marked // with __rel[a]_iplt_{start,end} symbols if it is a statically linked // executable. The runtime needs these symbols in order to resolve // all IRELATIVE relocs on startup. For dynamic executables, we don't // need these symbols, since IRELATIVE relocs are resolved through GOT // and PLT. For details, see http://www.airs.com/blog/archives/403. template void Writer::addRelIpltSymbols() { - if (needsInterpSection()) + if (Config->Relocatable || needsInterpSection()) return; StringRef S = Config->IsRela ? "__rela_iplt_start" : "__rel_iplt_start"; addOptionalRegular(S, InX::RelaIplt, 0, STV_HIDDEN, STB_WEAK); S = Config->IsRela ? "__rela_iplt_end" : "__rel_iplt_end"; ElfSym::RelaIpltEnd = addOptionalRegular(S, InX::RelaIplt, 0, STV_HIDDEN, STB_WEAK); } template void Writer::forEachRelSec( llvm::function_ref Fn) { // Scan all relocations. Each relocation goes through a series // of tests to determine if it needs special treatment, such as // creating GOT, PLT, copy relocations, etc. // Note that relocations for non-alloc sections are directly // processed by InputSection::relocateNonAlloc. for (InputSectionBase *IS : InputSections) if (IS->Live && isa(IS) && (IS->Flags & SHF_ALLOC)) Fn(*IS); for (EhInputSection *ES : InX::EhFrame->Sections) Fn(*ES); } // This function generates assignments for predefined symbols (e.g. _end or // _etext) and inserts them into the commands sequence to be processed at the // appropriate time. This ensures that the value is going to be correct by the // time any references to these symbols are processed and is equivalent to // defining these symbols explicitly in the linker script. template void Writer::setReservedSymbolSections() { if (ElfSym::GlobalOffsetTable) { // The _GLOBAL_OFFSET_TABLE_ symbol is defined by target convention usually // to the start of the .got or .got.plt section. InputSection *GotSection = InX::GotPlt; if (!Target->GotBaseSymInGotPlt) GotSection = InX::MipsGot ? cast(InX::MipsGot) : cast(InX::Got); ElfSym::GlobalOffsetTable->Section = GotSection; } if (ElfSym::RelaIpltEnd) ElfSym::RelaIpltEnd->Value = InX::RelaIplt->getSize(); PhdrEntry *Last = nullptr; PhdrEntry *LastRO = nullptr; for (PhdrEntry *P : Phdrs) { if (P->p_type != PT_LOAD) continue; Last = P; if (!(P->p_flags & PF_W)) LastRO = P; } if (LastRO) { // _etext is the first location after the last read-only loadable segment. if (ElfSym::Etext1) ElfSym::Etext1->Section = LastRO->LastSec; if (ElfSym::Etext2) ElfSym::Etext2->Section = LastRO->LastSec; } if (Last) { // _edata points to the end of the last mapped initialized section. OutputSection *Edata = nullptr; for (OutputSection *OS : OutputSections) { if (OS->Type != SHT_NOBITS) Edata = OS; if (OS == Last->LastSec) break; } if (ElfSym::Edata1) ElfSym::Edata1->Section = Edata; if (ElfSym::Edata2) ElfSym::Edata2->Section = Edata; // _end is the first location after the uninitialized data region. if (ElfSym::End1) ElfSym::End1->Section = Last->LastSec; if (ElfSym::End2) ElfSym::End2->Section = Last->LastSec; } if (ElfSym::Bss) ElfSym::Bss->Section = findSection(".bss"); // Setup MIPS _gp_disp/__gnu_local_gp symbols which should // be equal to the _gp symbol's value. if (ElfSym::MipsGp) { // Find GP-relative section with the lowest address // and use this address to calculate default _gp value. for (OutputSection *OS : OutputSections) { if (OS->Flags & SHF_MIPS_GPREL) { ElfSym::MipsGp->Section = OS; ElfSym::MipsGp->Value = 0x7ff0; break; } } } } // We want to find how similar two ranks are. // The more branches in getSectionRank that match, the more similar they are. // Since each branch corresponds to a bit flag, we can just use // countLeadingZeros. static int getRankProximityAux(OutputSection *A, OutputSection *B) { return countLeadingZeros(A->SortRank ^ B->SortRank); } static int getRankProximity(OutputSection *A, BaseCommand *B) { if (auto *Sec = dyn_cast(B)) return getRankProximityAux(A, Sec); return -1; } // When placing orphan sections, we want to place them after symbol assignments // so that an orphan after // begin_foo = .; // foo : { *(foo) } // end_foo = .; // doesn't break the intended meaning of the begin/end symbols. // We don't want to go over sections since findOrphanPos is the // one in charge of deciding the order of the sections. // We don't want to go over changes to '.', since doing so in // rx_sec : { *(rx_sec) } // . = ALIGN(0x1000); // /* The RW PT_LOAD starts here*/ // rw_sec : { *(rw_sec) } // would mean that the RW PT_LOAD would become unaligned. static bool shouldSkip(BaseCommand *Cmd) { if (auto *Assign = dyn_cast(Cmd)) return Assign->Name != "."; return false; } // We want to place orphan sections so that they share as much // characteristics with their neighbors as possible. For example, if // both are rw, or both are tls. template static std::vector::iterator findOrphanPos(std::vector::iterator B, std::vector::iterator E) { OutputSection *Sec = cast(*E); // Find the first element that has as close a rank as possible. auto I = std::max_element(B, E, [=](BaseCommand *A, BaseCommand *B) { return getRankProximity(Sec, A) < getRankProximity(Sec, B); }); if (I == E) return E; // Consider all existing sections with the same proximity. int Proximity = getRankProximity(Sec, *I); for (; I != E; ++I) { auto *CurSec = dyn_cast(*I); if (!CurSec) continue; if (getRankProximity(Sec, CurSec) != Proximity || Sec->SortRank < CurSec->SortRank) break; } auto IsOutputSec = [](BaseCommand *Cmd) { return isa(Cmd); }; auto J = std::find_if(llvm::make_reverse_iterator(I), llvm::make_reverse_iterator(B), IsOutputSec); I = J.base(); // As a special case, if the orphan section is the last section, put // it at the very end, past any other commands. // This matches bfd's behavior and is convenient when the linker script fully // specifies the start of the file, but doesn't care about the end (the non // alloc sections for example). auto NextSec = std::find_if(I, E, IsOutputSec); if (NextSec == E) return E; while (I != E && shouldSkip(*I)) ++I; return I; } // Builds section order for handling --symbol-ordering-file. static DenseMap buildSectionOrder() { DenseMap SectionOrder; // Use the rarely used option -call-graph-ordering-file to sort sections. if (!Config->CallGraphProfile.empty()) return computeCallGraphProfileOrder(); if (Config->SymbolOrderingFile.empty()) return SectionOrder; struct SymbolOrderEntry { int Priority; bool Present; }; // Build a map from symbols to their priorities. Symbols that didn't // appear in the symbol ordering file have the lowest priority 0. // All explicitly mentioned symbols have negative (higher) priorities. DenseMap SymbolOrder; int Priority = -Config->SymbolOrderingFile.size(); for (StringRef S : Config->SymbolOrderingFile) SymbolOrder.insert({S, {Priority++, false}}); // Build a map from sections to their priorities. auto AddSym = [&](Symbol &Sym) { auto It = SymbolOrder.find(Sym.getName()); if (It == SymbolOrder.end()) return; SymbolOrderEntry &Ent = It->second; Ent.Present = true; warnUnorderableSymbol(&Sym); if (auto *D = dyn_cast(&Sym)) { if (auto *Sec = dyn_cast_or_null(D->Section)) { int &Priority = SectionOrder[cast(Sec->Repl)]; Priority = std::min(Priority, Ent.Priority); } } }; // We want both global and local symbols. We get the global ones from the // symbol table and iterate the object files for the local ones. for (Symbol *Sym : Symtab->getSymbols()) if (!Sym->isLazy()) AddSym(*Sym); for (InputFile *File : ObjectFiles) for (Symbol *Sym : File->getSymbols()) if (Sym->isLocal()) AddSym(*Sym); if (Config->WarnSymbolOrdering) for (auto OrderEntry : SymbolOrder) if (!OrderEntry.second.Present) warn("symbol ordering file: no such symbol: " + OrderEntry.first); return SectionOrder; } // Sorts the sections in ISD according to the provided section order. static void sortISDBySectionOrder(InputSectionDescription *ISD, const DenseMap &Order) { std::vector UnorderedSections; std::vector> OrderedSections; uint64_t UnorderedSize = 0; for (InputSection *IS : ISD->Sections) { auto I = Order.find(IS); if (I == Order.end()) { UnorderedSections.push_back(IS); UnorderedSize += IS->getSize(); continue; } OrderedSections.push_back({IS, I->second}); } llvm::sort( OrderedSections.begin(), OrderedSections.end(), [&](std::pair A, std::pair B) { return A.second < B.second; }); // Find an insertion point for the ordered section list in the unordered // section list. On targets with limited-range branches, this is the mid-point // of the unordered section list. This decreases the likelihood that a range // extension thunk will be needed to enter or exit the ordered region. If the // ordered section list is a list of hot functions, we can generally expect // the ordered functions to be called more often than the unordered functions, // making it more likely that any particular call will be within range, and // therefore reducing the number of thunks required. // // For example, imagine that you have 8MB of hot code and 32MB of cold code. // If the layout is: // // 8MB hot // 32MB cold // // only the first 8-16MB of the cold code (depending on which hot function it // is actually calling) can call the hot code without a range extension thunk. // However, if we use this layout: // // 16MB cold // 8MB hot // 16MB cold // // both the last 8-16MB of the first block of cold code and the first 8-16MB // of the second block of cold code can call the hot code without a thunk. So // we effectively double the amount of code that could potentially call into // the hot code without a thunk. size_t InsPt = 0; if (Target->ThunkSectionSpacing && !OrderedSections.empty()) { uint64_t UnorderedPos = 0; for (; InsPt != UnorderedSections.size(); ++InsPt) { UnorderedPos += UnorderedSections[InsPt]->getSize(); if (UnorderedPos > UnorderedSize / 2) break; } } ISD->Sections.clear(); for (InputSection *IS : makeArrayRef(UnorderedSections).slice(0, InsPt)) ISD->Sections.push_back(IS); for (std::pair P : OrderedSections) ISD->Sections.push_back(P.first); for (InputSection *IS : makeArrayRef(UnorderedSections).slice(InsPt)) ISD->Sections.push_back(IS); } static void sortSection(OutputSection *Sec, const DenseMap &Order) { StringRef Name = Sec->Name; // Sort input sections by section name suffixes for // __attribute__((init_priority(N))). if (Name == ".init_array" || Name == ".fini_array") { if (!Script->HasSectionsCommand) Sec->sortInitFini(); return; } // Sort input sections by the special rule for .ctors and .dtors. if (Name == ".ctors" || Name == ".dtors") { if (!Script->HasSectionsCommand) Sec->sortCtorsDtors(); return; } // Never sort these. if (Name == ".init" || Name == ".fini") return; // Sort input sections by priority using the list provided // by --symbol-ordering-file. if (!Order.empty()) for (BaseCommand *B : Sec->SectionCommands) if (auto *ISD = dyn_cast(B)) sortISDBySectionOrder(ISD, Order); } // If no layout was provided by linker script, we want to apply default // sorting for special input sections. This also handles --symbol-ordering-file. template void Writer::sortInputSections() { // Build the order once since it is expensive. DenseMap Order = buildSectionOrder(); for (BaseCommand *Base : Script->SectionCommands) if (auto *Sec = dyn_cast(Base)) sortSection(Sec, Order); } template void Writer::sortSections() { Script->adjustSectionsBeforeSorting(); // Don't sort if using -r. It is not necessary and we want to preserve the // relative order for SHF_LINK_ORDER sections. if (Config->Relocatable) return; sortInputSections(); for (BaseCommand *Base : Script->SectionCommands) { auto *OS = dyn_cast(Base); if (!OS) continue; OS->SortRank = getSectionRank(OS); // We want to assign rude approximation values to OutSecOff fields // to know the relative order of the input sections. We use it for // sorting SHF_LINK_ORDER sections. See resolveShfLinkOrder(). uint64_t I = 0; for (InputSection *Sec : getInputSections(OS)) Sec->OutSecOff = I++; } if (!Script->HasSectionsCommand) { // We know that all the OutputSections are contiguous in this case. auto IsSection = [](BaseCommand *Base) { return isa(Base); }; std::stable_sort( llvm::find_if(Script->SectionCommands, IsSection), llvm::find_if(llvm::reverse(Script->SectionCommands), IsSection).base(), compareSections); return; } // Orphan sections are sections present in the input files which are // not explicitly placed into the output file by the linker script. // // The sections in the linker script are already in the correct // order. We have to figuere out where to insert the orphan // sections. // // The order of the sections in the script is arbitrary and may not agree with // compareSections. This means that we cannot easily define a strict weak // ordering. To see why, consider a comparison of a section in the script and // one not in the script. We have a two simple options: // * Make them equivalent (a is not less than b, and b is not less than a). // The problem is then that equivalence has to be transitive and we can // have sections a, b and c with only b in a script and a less than c // which breaks this property. // * Use compareSectionsNonScript. Given that the script order doesn't have // to match, we can end up with sections a, b, c, d where b and c are in the // script and c is compareSectionsNonScript less than b. In which case d // can be equivalent to c, a to b and d < a. As a concrete example: // .a (rx) # not in script // .b (rx) # in script // .c (ro) # in script // .d (ro) # not in script // // The way we define an order then is: // * Sort only the orphan sections. They are in the end right now. // * Move each orphan section to its preferred position. We try // to put each section in the last position where it can share // a PT_LOAD. // // There is some ambiguity as to where exactly a new entry should be // inserted, because Commands contains not only output section // commands but also other types of commands such as symbol assignment // expressions. There's no correct answer here due to the lack of the // formal specification of the linker script. We use heuristics to // determine whether a new output command should be added before or // after another commands. For the details, look at shouldSkip // function. auto I = Script->SectionCommands.begin(); auto E = Script->SectionCommands.end(); auto NonScriptI = std::find_if(I, E, [](BaseCommand *Base) { if (auto *Sec = dyn_cast(Base)) return Sec->SectionIndex == UINT32_MAX; return false; }); // Sort the orphan sections. std::stable_sort(NonScriptI, E, compareSections); // As a horrible special case, skip the first . assignment if it is before any // section. We do this because it is common to set a load address by starting // the script with ". = 0xabcd" and the expectation is that every section is // after that. auto FirstSectionOrDotAssignment = std::find_if(I, E, [](BaseCommand *Cmd) { return !shouldSkip(Cmd); }); if (FirstSectionOrDotAssignment != E && isa(**FirstSectionOrDotAssignment)) ++FirstSectionOrDotAssignment; I = FirstSectionOrDotAssignment; while (NonScriptI != E) { auto Pos = findOrphanPos(I, NonScriptI); OutputSection *Orphan = cast(*NonScriptI); // As an optimization, find all sections with the same sort rank // and insert them with one rotate. unsigned Rank = Orphan->SortRank; auto End = std::find_if(NonScriptI + 1, E, [=](BaseCommand *Cmd) { return cast(Cmd)->SortRank != Rank; }); std::rotate(Pos, NonScriptI, End); NonScriptI = End; } Script->adjustSectionsAfterSorting(); } static bool compareByFilePosition(InputSection *A, InputSection *B) { // Synthetic, i. e. a sentinel section, should go last. if (A->kind() == InputSectionBase::Synthetic || B->kind() == InputSectionBase::Synthetic) return A->kind() != InputSectionBase::Synthetic; InputSection *LA = A->getLinkOrderDep(); InputSection *LB = B->getLinkOrderDep(); OutputSection *AOut = LA->getParent(); OutputSection *BOut = LB->getParent(); if (AOut != BOut) return AOut->SectionIndex < BOut->SectionIndex; return LA->OutSecOff < LB->OutSecOff; } // This function is used by the --merge-exidx-entries to detect duplicate // .ARM.exidx sections. It is Arm only. // // The .ARM.exidx section is of the form: // | PREL31 offset to function | Unwind instructions for function | // where the unwind instructions are either a small number of unwind // instructions inlined into the table entry, the special CANT_UNWIND value of // 0x1 or a PREL31 offset into a .ARM.extab Section that contains unwind // instructions. // // We return true if all the unwind instructions in the .ARM.exidx entries of // Cur can be merged into the last entry of Prev. static bool isDuplicateArmExidxSec(InputSection *Prev, InputSection *Cur) { // References to .ARM.Extab Sections have bit 31 clear and are not the // special EXIDX_CANTUNWIND bit-pattern. auto IsExtabRef = [](uint32_t Unwind) { return (Unwind & 0x80000000) == 0 && Unwind != 0x1; }; struct ExidxEntry { ulittle32_t Fn; ulittle32_t Unwind; }; // Get the last table Entry from the previous .ARM.exidx section. const ExidxEntry &PrevEntry = Prev->getDataAs().back(); if (IsExtabRef(PrevEntry.Unwind)) return false; // We consider the unwind instructions of an .ARM.exidx table entry // a duplicate if the previous unwind instructions if: // - Both are the special EXIDX_CANTUNWIND. // - Both are the same inline unwind instructions. // We do not attempt to follow and check links into .ARM.extab tables as // consecutive identical entries are rare and the effort to check that they // are identical is high. for (const ExidxEntry Entry : Cur->getDataAs()) if (IsExtabRef(Entry.Unwind) || Entry.Unwind != PrevEntry.Unwind) return false; // All table entries in this .ARM.exidx Section can be merged into the // previous Section. return true; } template void Writer::resolveShfLinkOrder() { for (OutputSection *Sec : OutputSections) { if (!(Sec->Flags & SHF_LINK_ORDER)) continue; // Link order may be distributed across several InputSectionDescriptions // but sort must consider them all at once. std::vector ScriptSections; std::vector Sections; for (BaseCommand *Base : Sec->SectionCommands) { if (auto *ISD = dyn_cast(Base)) { for (InputSection *&IS : ISD->Sections) { ScriptSections.push_back(&IS); Sections.push_back(IS); } } } std::stable_sort(Sections.begin(), Sections.end(), compareByFilePosition); if (!Config->Relocatable && Config->EMachine == EM_ARM && Sec->Type == SHT_ARM_EXIDX) { if (auto *Sentinel = dyn_cast(Sections.back())) { assert(Sections.size() >= 2 && "We should create a sentinel section only if there are " "alive regular exidx sections."); // The last executable section is required to fill the sentinel. // Remember it here so that we don't have to find it again. Sentinel->Highest = Sections[Sections.size() - 2]->getLinkOrderDep(); } if (Config->MergeArmExidx) { // The EHABI for the Arm Architecture permits consecutive identical // table entries to be merged. We use a simple implementation that // removes a .ARM.exidx Input Section if it can be merged into the // previous one. This does not require any rewriting of InputSection // contents but misses opportunities for fine grained deduplication // where only a subset of the InputSection contents can be merged. size_t Prev = 0; // The last one is a sentinel entry which should not be removed. for (size_t I = 1; I < Sections.size() - 1; ++I) { if (isDuplicateArmExidxSec(Sections[Prev], Sections[I])) Sections[I] = nullptr; else Prev = I; } } } for (int I = 0, N = Sections.size(); I < N; ++I) *ScriptSections[I] = Sections[I]; // Remove the Sections we marked as duplicate earlier. for (BaseCommand *Base : Sec->SectionCommands) if (auto *ISD = dyn_cast(Base)) llvm::erase_if(ISD->Sections, [](InputSection *IS) { return !IS; }); } } static void applySynthetic(const std::vector &Sections, llvm::function_ref Fn) { for (SyntheticSection *SS : Sections) if (SS && SS->getParent() && !SS->empty()) Fn(SS); } // In order to allow users to manipulate linker-synthesized sections, // we had to add synthetic sections to the input section list early, // even before we make decisions whether they are needed. This allows // users to write scripts like this: ".mygot : { .got }". // // Doing it has an unintended side effects. If it turns out that we // don't need a .got (for example) at all because there's no // relocation that needs a .got, we don't want to emit .got. // // To deal with the above problem, this function is called after // scanRelocations is called to remove synthetic sections that turn // out to be empty. static void removeUnusedSyntheticSections() { // All input synthetic sections that can be empty are placed after // all regular ones. We iterate over them all and exit at first // non-synthetic. for (InputSectionBase *S : llvm::reverse(InputSections)) { SyntheticSection *SS = dyn_cast(S); if (!SS) return; OutputSection *OS = SS->getParent(); if (!OS || !SS->empty()) continue; // If we reach here, then SS is an unused synthetic section and we want to // remove it from corresponding input section description of output section. for (BaseCommand *B : OS->SectionCommands) if (auto *ISD = dyn_cast(B)) llvm::erase_if(ISD->Sections, [=](InputSection *IS) { return IS == SS; }); } } // Returns true if a symbol can be replaced at load-time by a symbol // with the same name defined in other ELF executable or DSO. static bool computeIsPreemptible(const Symbol &B) { assert(!B.isLocal()); // Only symbols that appear in dynsym can be preempted. if (!B.includeInDynsym()) return false; // Only default visibility symbols can be preempted. if (B.Visibility != STV_DEFAULT) return false; // At this point copy relocations have not been created yet, so any // symbol that is not defined locally is preemptible. if (!B.isDefined()) return true; // If we have a dynamic list it specifies which local symbols are preemptible. if (Config->HasDynamicList) return false; if (!Config->Shared) return false; // -Bsymbolic means that definitions are not preempted. if (Config->Bsymbolic || (Config->BsymbolicFunctions && B.isFunc())) return false; return true; } // Create output section objects and add them to OutputSections. template void Writer::finalizeSections() { Out::DebugInfo = findSection(".debug_info"); Out::PreinitArray = findSection(".preinit_array"); Out::InitArray = findSection(".init_array"); Out::FiniArray = findSection(".fini_array"); // The linker needs to define SECNAME_start, SECNAME_end and SECNAME_stop // symbols for sections, so that the runtime can get the start and end // addresses of each section by section name. Add such symbols. if (!Config->Relocatable) { addStartEndSymbols(); for (BaseCommand *Base : Script->SectionCommands) if (auto *Sec = dyn_cast(Base)) addStartStopSymbols(Sec); } // Add _DYNAMIC symbol. Unlike GNU gold, our _DYNAMIC symbol has no type. // It should be okay as no one seems to care about the type. // Even the author of gold doesn't remember why gold behaves that way. // https://sourceware.org/ml/binutils/2002-03/msg00360.html if (InX::DynSymTab) Symtab->addRegular("_DYNAMIC", STV_HIDDEN, STT_NOTYPE, 0 /*Value*/, /*Size=*/0, STB_WEAK, InX::Dynamic, /*File=*/nullptr); // Define __rel[a]_iplt_{start,end} symbols if needed. addRelIpltSymbols(); // This responsible for splitting up .eh_frame section into // pieces. The relocation scan uses those pieces, so this has to be // earlier. applySynthetic({InX::EhFrame}, [](SyntheticSection *SS) { SS->finalizeContents(); }); for (Symbol *S : Symtab->getSymbols()) S->IsPreemptible |= computeIsPreemptible(*S); // Scan relocations. This must be done after every symbol is declared so that // we can correctly decide if a dynamic relocation is needed. if (!Config->Relocatable) forEachRelSec(scanRelocations); if (InX::Plt && !InX::Plt->empty()) InX::Plt->addSymbols(); if (InX::Iplt && !InX::Iplt->empty()) InX::Iplt->addSymbols(); // Now that we have defined all possible global symbols including linker- // synthesized ones. Visit all symbols to give the finishing touches. for (Symbol *Sym : Symtab->getSymbols()) { if (!includeInSymtab(*Sym)) continue; if (InX::SymTab) InX::SymTab->addSymbol(Sym); if (InX::DynSymTab && Sym->includeInDynsym()) { InX::DynSymTab->addSymbol(Sym); if (auto *File = dyn_cast_or_null>(Sym->File)) if (File->IsNeeded && !Sym->isUndefined()) In::VerNeed->addSymbol(Sym); } } // Do not proceed if there was an undefined symbol. if (errorCount()) return; if (InX::MipsGot) InX::MipsGot->build(); removeUnusedSyntheticSections(); sortSections(); // Now that we have the final list, create a list of all the // OutputSections for convenience. for (BaseCommand *Base : Script->SectionCommands) if (auto *Sec = dyn_cast(Base)) OutputSections.push_back(Sec); // Ensure data sections are not mixed with executable sections when // -execute-only is used. if (Config->ExecuteOnly) for (OutputSection *OS : OutputSections) if (OS->Flags & SHF_EXECINSTR) for (InputSection *IS : getInputSections(OS)) if (!(IS->Flags & SHF_EXECINSTR)) error("-execute-only does not support intermingling data and code"); // Prefer command line supplied address over other constraints. for (OutputSection *Sec : OutputSections) { auto I = Config->SectionStartMap.find(Sec->Name); if (I != Config->SectionStartMap.end()) Sec->AddrExpr = [=] { return I->second; }; } // This is a bit of a hack. A value of 0 means undef, so we set it // to 1 to make __ehdr_start defined. The section number is not // particularly relevant. Out::ElfHeader->SectionIndex = 1; unsigned I = 1; for (OutputSection *Sec : OutputSections) { Sec->SectionIndex = I++; Sec->ShName = InX::ShStrTab->addString(Sec->Name); } // Binary and relocatable output does not have PHDRS. // The headers have to be created before finalize as that can influence the // image base and the dynamic section on mips includes the image base. if (!Config->Relocatable && !Config->OFormatBinary) { Phdrs = Script->hasPhdrsCommands() ? Script->createPhdrs() : createPhdrs(); addPtArmExid(Phdrs); Out::ProgramHeaders->Size = sizeof(Elf_Phdr) * Phdrs.size(); } // Some symbols are defined in term of program headers. Now that we // have the headers, we can find out which sections they point to. setReservedSymbolSections(); // Dynamic section must be the last one in this list and dynamic // symbol table section (DynSymTab) must be the first one. applySynthetic( {InX::DynSymTab, InX::Bss, InX::BssRelRo, InX::GnuHashTab, InX::HashTab, InX::SymTab, InX::SymTabShndx, InX::ShStrTab, InX::StrTab, In::VerDef, InX::DynStrTab, InX::Got, InX::MipsGot, InX::IgotPlt, InX::GotPlt, InX::RelaDyn, InX::RelrDyn, InX::RelaIplt, InX::RelaPlt, InX::Plt, InX::Iplt, InX::EhFrameHdr, In::VerSym, In::VerNeed, InX::Dynamic}, [](SyntheticSection *SS) { SS->finalizeContents(); }); if (!Script->HasSectionsCommand && !Config->Relocatable) fixSectionAlignments(); // After link order processing .ARM.exidx sections can be deduplicated, which // needs to be resolved before any other address dependent operation. resolveShfLinkOrder(); // Some architectures need to generate content that depends on the address // of InputSections. For example some architectures use small displacements // for jump instructions that is the linker's responsibility for creating // range extension thunks for. As the generation of the content may also // alter InputSection addresses we must converge to a fixed point. if (Target->NeedsThunks || Config->AndroidPackDynRelocs || Config->RelrPackDynRelocs) { ThunkCreator TC; AArch64Err843419Patcher A64P; bool Changed; do { Script->assignAddresses(); Changed = false; if (Target->NeedsThunks) Changed |= TC.createThunks(OutputSections); if (Config->FixCortexA53Errata843419) { if (Changed) Script->assignAddresses(); Changed |= A64P.createFixes(); } if (InX::MipsGot) InX::MipsGot->updateAllocSize(); Changed |= InX::RelaDyn->updateAllocSize(); if (InX::RelrDyn) Changed |= InX::RelrDyn->updateAllocSize(); } while (Changed); } // createThunks may have added local symbols to the static symbol table applySynthetic({InX::SymTab}, [](SyntheticSection *SS) { SS->postThunkContents(); }); // Fill other section headers. The dynamic table is finalized // at the end because some tags like RELSZ depend on result // of finalizing other sections. for (OutputSection *Sec : OutputSections) Sec->finalize(); } // The linker is expected to define SECNAME_start and SECNAME_end // symbols for a few sections. This function defines them. template void Writer::addStartEndSymbols() { // If a section does not exist, there's ambiguity as to how we // define _start and _end symbols for an init/fini section. Since // the loader assume that the symbols are always defined, we need to // always define them. But what value? The loader iterates over all // pointers between _start and _end to run global ctors/dtors, so if // the section is empty, their symbol values don't actually matter // as long as _start and _end point to the same location. // // That said, we don't want to set the symbols to 0 (which is // probably the simplest value) because that could cause some // program to fail to link due to relocation overflow, if their // program text is above 2 GiB. We use the address of the .text // section instead to prevent that failure. OutputSection *Default = findSection(".text"); if (!Default) Default = Out::ElfHeader; auto Define = [=](StringRef Start, StringRef End, OutputSection *OS) { if (OS) { addOptionalRegular(Start, OS, 0); addOptionalRegular(End, OS, -1); } else { addOptionalRegular(Start, Default, 0); addOptionalRegular(End, Default, 0); } }; Define("__preinit_array_start", "__preinit_array_end", Out::PreinitArray); Define("__init_array_start", "__init_array_end", Out::InitArray); Define("__fini_array_start", "__fini_array_end", Out::FiniArray); if (OutputSection *Sec = findSection(".ARM.exidx")) Define("__exidx_start", "__exidx_end", Sec); } // If a section name is valid as a C identifier (which is rare because of // the leading '.'), linkers are expected to define __start_ and // __stop_ symbols. They are at beginning and end of the section, // respectively. This is not requested by the ELF standard, but GNU ld and // gold provide the feature, and used by many programs. template void Writer::addStartStopSymbols(OutputSection *Sec) { StringRef S = Sec->Name; if (!isValidCIdentifier(S)) return; addOptionalRegular(Saver.save("__start_" + S), Sec, 0, STV_PROTECTED); addOptionalRegular(Saver.save("__stop_" + S), Sec, -1, STV_PROTECTED); } static bool needsPtLoad(OutputSection *Sec) { if (!(Sec->Flags & SHF_ALLOC) || Sec->Noload) return false; // Don't allocate VA space for TLS NOBITS sections. The PT_TLS PHDR is // responsible for allocating space for them, not the PT_LOAD that // contains the TLS initialization image. if (Sec->Flags & SHF_TLS && Sec->Type == SHT_NOBITS) return false; return true; } // Linker scripts are responsible for aligning addresses. Unfortunately, most // linker scripts are designed for creating two PT_LOADs only, one RX and one // RW. This means that there is no alignment in the RO to RX transition and we // cannot create a PT_LOAD there. static uint64_t computeFlags(uint64_t Flags) { if (Config->Omagic) return PF_R | PF_W | PF_X; if (Config->ExecuteOnly && (Flags & PF_X)) return Flags & ~PF_R; if (Config->SingleRoRx && !(Flags & PF_W)) return Flags | PF_X; return Flags; } // Decide which program headers to create and which sections to include in each // one. template std::vector Writer::createPhdrs() { std::vector Ret; auto AddHdr = [&](unsigned Type, unsigned Flags) -> PhdrEntry * { Ret.push_back(make(Type, Flags)); return Ret.back(); }; // The first phdr entry is PT_PHDR which describes the program header itself. AddHdr(PT_PHDR, PF_R)->add(Out::ProgramHeaders); // PT_INTERP must be the second entry if exists. if (OutputSection *Cmd = findSection(".interp")) AddHdr(PT_INTERP, Cmd->getPhdrFlags())->add(Cmd); // Add the first PT_LOAD segment for regular output sections. uint64_t Flags = computeFlags(PF_R); PhdrEntry *Load = AddHdr(PT_LOAD, Flags); // Add the headers. We will remove them if they don't fit. Load->add(Out::ElfHeader); Load->add(Out::ProgramHeaders); for (OutputSection *Sec : OutputSections) { if (!(Sec->Flags & SHF_ALLOC)) break; if (!needsPtLoad(Sec)) continue; // Segments are contiguous memory regions that has the same attributes // (e.g. executable or writable). There is one phdr for each segment. // Therefore, we need to create a new phdr when the next section has // different flags or is loaded at a discontiguous address or memory // region using AT or AT> linker script command, respectively. At the same // time, we don't want to create a separate load segment for the headers, // even if the first output section has an AT or AT> attribute. uint64_t NewFlags = computeFlags(Sec->getPhdrFlags()); if (((Sec->LMAExpr || (Sec->LMARegion && (Sec->LMARegion != Load->FirstSec->LMARegion))) && Load->LastSec != Out::ProgramHeaders) || Sec->MemRegion != Load->FirstSec->MemRegion || Flags != NewFlags) { Load = AddHdr(PT_LOAD, NewFlags); Flags = NewFlags; } Load->add(Sec); } // Add a TLS segment if any. PhdrEntry *TlsHdr = make(PT_TLS, PF_R); for (OutputSection *Sec : OutputSections) if (Sec->Flags & SHF_TLS) TlsHdr->add(Sec); if (TlsHdr->FirstSec) Ret.push_back(TlsHdr); // Add an entry for .dynamic. if (InX::DynSymTab) AddHdr(PT_DYNAMIC, InX::Dynamic->getParent()->getPhdrFlags()) ->add(InX::Dynamic->getParent()); // PT_GNU_RELRO includes all sections that should be marked as // read-only by dynamic linker after proccessing relocations. // Current dynamic loaders only support one PT_GNU_RELRO PHDR, give // an error message if more than one PT_GNU_RELRO PHDR is required. PhdrEntry *RelRo = make(PT_GNU_RELRO, PF_R); bool InRelroPhdr = false; bool IsRelroFinished = false; for (OutputSection *Sec : OutputSections) { if (!needsPtLoad(Sec)) continue; if (isRelroSection(Sec)) { InRelroPhdr = true; if (!IsRelroFinished) RelRo->add(Sec); else error("section: " + Sec->Name + " is not contiguous with other relro" + " sections"); } else if (InRelroPhdr) { InRelroPhdr = false; IsRelroFinished = true; } } if (RelRo->FirstSec) Ret.push_back(RelRo); // PT_GNU_EH_FRAME is a special section pointing on .eh_frame_hdr. if (!InX::EhFrame->empty() && InX::EhFrameHdr && InX::EhFrame->getParent() && InX::EhFrameHdr->getParent()) AddHdr(PT_GNU_EH_FRAME, InX::EhFrameHdr->getParent()->getPhdrFlags()) ->add(InX::EhFrameHdr->getParent()); // PT_OPENBSD_RANDOMIZE is an OpenBSD-specific feature. That makes // the dynamic linker fill the segment with random data. if (OutputSection *Cmd = findSection(".openbsd.randomdata")) AddHdr(PT_OPENBSD_RANDOMIZE, Cmd->getPhdrFlags())->add(Cmd); // PT_GNU_STACK is a special section to tell the loader to make the // pages for the stack non-executable. If you really want an executable // stack, you can pass -z execstack, but that's not recommended for // security reasons. unsigned Perm = PF_R | PF_W; if (Config->ZExecstack) Perm |= PF_X; AddHdr(PT_GNU_STACK, Perm)->p_memsz = Config->ZStackSize; // PT_OPENBSD_WXNEEDED is a OpenBSD-specific header to mark the executable // is expected to perform W^X violations, such as calling mprotect(2) or // mmap(2) with PROT_WRITE | PROT_EXEC, which is prohibited by default on // OpenBSD. if (Config->ZWxneeded) AddHdr(PT_OPENBSD_WXNEEDED, PF_X); // Create one PT_NOTE per a group of contiguous .note sections. PhdrEntry *Note = nullptr; for (OutputSection *Sec : OutputSections) { if (Sec->Type == SHT_NOTE && (Sec->Flags & SHF_ALLOC)) { if (!Note || Sec->LMAExpr) Note = AddHdr(PT_NOTE, PF_R); Note->add(Sec); } else { Note = nullptr; } } return Ret; } template void Writer::addPtArmExid(std::vector &Phdrs) { if (Config->EMachine != EM_ARM) return; auto I = llvm::find_if(OutputSections, [](OutputSection *Cmd) { return Cmd->Type == SHT_ARM_EXIDX; }); if (I == OutputSections.end()) return; // PT_ARM_EXIDX is the ARM EHABI equivalent of PT_GNU_EH_FRAME PhdrEntry *ARMExidx = make(PT_ARM_EXIDX, PF_R); ARMExidx->add(*I); Phdrs.push_back(ARMExidx); } // The first section of each PT_LOAD, the first section in PT_GNU_RELRO and the // first section after PT_GNU_RELRO have to be page aligned so that the dynamic // linker can set the permissions. template void Writer::fixSectionAlignments() { auto PageAlign = [](OutputSection *Cmd) { if (Cmd && !Cmd->AddrExpr) Cmd->AddrExpr = [=] { return alignTo(Script->getDot(), Config->MaxPageSize); }; }; for (const PhdrEntry *P : Phdrs) if (P->p_type == PT_LOAD && P->FirstSec) PageAlign(P->FirstSec); for (const PhdrEntry *P : Phdrs) { if (P->p_type != PT_GNU_RELRO) continue; if (P->FirstSec) PageAlign(P->FirstSec); // Find the first section after PT_GNU_RELRO. If it is in a PT_LOAD we // have to align it to a page. auto End = OutputSections.end(); auto I = std::find(OutputSections.begin(), End, P->LastSec); if (I == End || (I + 1) == End) continue; OutputSection *Cmd = (*(I + 1)); if (needsPtLoad(Cmd)) PageAlign(Cmd); } } // Adjusts the file alignment for a given output section and returns // its new file offset. The file offset must be the same with its // virtual address (modulo the page size) so that the loader can load // executables without any address adjustment. static uint64_t getFileAlignment(uint64_t Off, OutputSection *Cmd) { OutputSection *First = Cmd->PtLoad ? Cmd->PtLoad->FirstSec : nullptr; // The first section in a PT_LOAD has to have congruent offset and address // module the page size. if (Cmd == First) return alignTo(Off, std::max(Cmd->Alignment, Config->MaxPageSize), Cmd->Addr); // For SHT_NOBITS we don't want the alignment of the section to impact the // offset of the sections that follow. Since nothing seems to care about the // sh_offset of the SHT_NOBITS section itself, just ignore it. if (Cmd->Type == SHT_NOBITS) return Off; // If the section is not in a PT_LOAD, we just have to align it. if (!Cmd->PtLoad) return alignTo(Off, Cmd->Alignment); // If two sections share the same PT_LOAD the file offset is calculated // using this formula: Off2 = Off1 + (VA2 - VA1). return First->Offset + Cmd->Addr - First->Addr; } static uint64_t setOffset(OutputSection *Cmd, uint64_t Off) { Off = getFileAlignment(Off, Cmd); Cmd->Offset = Off; // For SHT_NOBITS we should not count the size. if (Cmd->Type == SHT_NOBITS) return Off; return Off + Cmd->Size; } template void Writer::assignFileOffsetsBinary() { uint64_t Off = 0; for (OutputSection *Sec : OutputSections) if (Sec->Flags & SHF_ALLOC) Off = setOffset(Sec, Off); FileSize = alignTo(Off, Config->Wordsize); } static std::string rangeToString(uint64_t Addr, uint64_t Len) { if (Len == 0) return ""; return "[0x" + utohexstr(Addr) + ", 0x" + utohexstr(Addr + Len - 1) + "]"; } // Assign file offsets to output sections. template void Writer::assignFileOffsets() { uint64_t Off = 0; Off = setOffset(Out::ElfHeader, Off); Off = setOffset(Out::ProgramHeaders, Off); PhdrEntry *LastRX = nullptr; for (PhdrEntry *P : Phdrs) if (P->p_type == PT_LOAD && (P->p_flags & PF_X)) LastRX = P; for (OutputSection *Sec : OutputSections) { Off = setOffset(Sec, Off); if (Script->HasSectionsCommand) continue; // If this is a last section of the last executable segment and that // segment is the last loadable segment, align the offset of the // following section to avoid loading non-segments parts of the file. if (LastRX && LastRX->LastSec == Sec) Off = alignTo(Off, Target->PageSize); } SectionHeaderOff = alignTo(Off, Config->Wordsize); FileSize = SectionHeaderOff + (OutputSections.size() + 1) * sizeof(Elf_Shdr); // Our logic assumes that sections have rising VA within the same segment. // With use of linker scripts it is possible to violate this rule and get file // offset overlaps or overflows. That should never happen with a valid script // which does not move the location counter backwards and usually scripts do // not do that. Unfortunately, there are apps in the wild, for example, Linux // kernel, which control segment distribution explicitly and move the counter // backwards, so we have to allow doing that to support linking them. We // perform non-critical checks for overlaps in checkSectionOverlap(), but here // we want to prevent file size overflows because it would crash the linker. for (OutputSection *Sec : OutputSections) { if (Sec->Type == SHT_NOBITS) continue; if ((Sec->Offset > FileSize) || (Sec->Offset + Sec->Size > FileSize)) error("unable to place section " + Sec->Name + " at file offset " + rangeToString(Sec->Offset, Sec->Offset + Sec->Size) + "; check your linker script for overflows"); } } // Finalize the program headers. We call this function after we assign // file offsets and VAs to all sections. template void Writer::setPhdrs() { for (PhdrEntry *P : Phdrs) { OutputSection *First = P->FirstSec; OutputSection *Last = P->LastSec; if (First) { P->p_filesz = Last->Offset - First->Offset; if (Last->Type != SHT_NOBITS) P->p_filesz += Last->Size; P->p_memsz = Last->Addr + Last->Size - First->Addr; P->p_offset = First->Offset; P->p_vaddr = First->Addr; if (!P->HasLMA) P->p_paddr = First->getLMA(); } if (P->p_type == PT_LOAD) P->p_align = std::max(P->p_align, Config->MaxPageSize); else if (P->p_type == PT_GNU_RELRO) { P->p_align = 1; // The glibc dynamic loader rounds the size down, so we need to round up // to protect the last page. This is a no-op on FreeBSD which always // rounds up. P->p_memsz = alignTo(P->p_memsz, Target->PageSize); } // The TLS pointer goes after PT_TLS. At least glibc will align it, // so round up the size to make sure the offsets are correct. if (P->p_type == PT_TLS) { Out::TlsPhdr = P; if (P->p_memsz) P->p_memsz = alignTo(P->p_memsz, P->p_align); } } } // A helper struct for checkSectionOverlap. namespace { struct SectionOffset { OutputSection *Sec; uint64_t Offset; }; } // namespace // Check whether sections overlap for a specific address range (file offsets, // load and virtual adresses). static void checkOverlap(StringRef Name, std::vector &Sections, bool IsVirtualAddr) { llvm::sort(Sections.begin(), Sections.end(), [=](const SectionOffset &A, const SectionOffset &B) { return A.Offset < B.Offset; }); // Finding overlap is easy given a vector is sorted by start position. // If an element starts before the end of the previous element, they overlap. for (size_t I = 1, End = Sections.size(); I < End; ++I) { SectionOffset A = Sections[I - 1]; SectionOffset B = Sections[I]; if (B.Offset >= A.Offset + A.Sec->Size) continue; // If both sections are in OVERLAY we allow the overlapping of virtual // addresses, because it is what OVERLAY was designed for. if (IsVirtualAddr && A.Sec->InOverlay && B.Sec->InOverlay) continue; errorOrWarn("section " + A.Sec->Name + " " + Name + " range overlaps with " + B.Sec->Name + "\n>>> " + A.Sec->Name + " range is " + rangeToString(A.Offset, A.Sec->Size) + "\n>>> " + B.Sec->Name + " range is " + rangeToString(B.Offset, B.Sec->Size)); } } // Check for overlapping sections and address overflows. // // In this function we check that none of the output sections have overlapping // file offsets. For SHF_ALLOC sections we also check that the load address // ranges and the virtual address ranges don't overlap template void Writer::checkSections() { // First, check that section's VAs fit in available address space for target. for (OutputSection *OS : OutputSections) if ((OS->Addr + OS->Size < OS->Addr) || (!ELFT::Is64Bits && OS->Addr + OS->Size > UINT32_MAX)) errorOrWarn("section " + OS->Name + " at 0x" + utohexstr(OS->Addr) + " of size 0x" + utohexstr(OS->Size) + " exceeds available address space"); // Check for overlapping file offsets. In this case we need to skip any // section marked as SHT_NOBITS. These sections don't actually occupy space in // the file so Sec->Offset + Sec->Size can overlap with others. If --oformat // binary is specified only add SHF_ALLOC sections are added to the output // file so we skip any non-allocated sections in that case. std::vector FileOffs; for (OutputSection *Sec : OutputSections) if (0 < Sec->Size && Sec->Type != SHT_NOBITS && (!Config->OFormatBinary || (Sec->Flags & SHF_ALLOC))) FileOffs.push_back({Sec, Sec->Offset}); checkOverlap("file", FileOffs, false); // When linking with -r there is no need to check for overlapping virtual/load // addresses since those addresses will only be assigned when the final // executable/shared object is created. if (Config->Relocatable) return; // Checking for overlapping virtual and load addresses only needs to take // into account SHF_ALLOC sections since others will not be loaded. // Furthermore, we also need to skip SHF_TLS sections since these will be // mapped to other addresses at runtime and can therefore have overlapping // ranges in the file. std::vector VMAs; for (OutputSection *Sec : OutputSections) if (0 < Sec->Size && (Sec->Flags & SHF_ALLOC) && !(Sec->Flags & SHF_TLS)) VMAs.push_back({Sec, Sec->Addr}); checkOverlap("virtual address", VMAs, true); // Finally, check that the load addresses don't overlap. This will usually be // the same as the virtual addresses but can be different when using a linker // script with AT(). std::vector LMAs; for (OutputSection *Sec : OutputSections) if (0 < Sec->Size && (Sec->Flags & SHF_ALLOC) && !(Sec->Flags & SHF_TLS)) LMAs.push_back({Sec, Sec->getLMA()}); checkOverlap("load address", LMAs, false); } // The entry point address is chosen in the following ways. // // 1. the '-e' entry command-line option; // 2. the ENTRY(symbol) command in a linker control script; // 3. the value of the symbol _start, if present; // 4. the number represented by the entry symbol, if it is a number; // 5. the address of the first byte of the .text section, if present; // 6. the address 0. template uint64_t Writer::getEntryAddr() { // Case 1, 2 or 3 if (Symbol *B = Symtab->find(Config->Entry)) return B->getVA(); // Case 4 uint64_t Addr; if (to_integer(Config->Entry, Addr)) return Addr; // Case 5 if (OutputSection *Sec = findSection(".text")) { if (Config->WarnMissingEntry) warn("cannot find entry symbol " + Config->Entry + "; defaulting to 0x" + utohexstr(Sec->Addr)); return Sec->Addr; } // Case 6 if (Config->WarnMissingEntry) warn("cannot find entry symbol " + Config->Entry + "; not setting start address"); return 0; } static uint16_t getELFType() { if (Config->Pic) return ET_DYN; if (Config->Relocatable) return ET_REL; return ET_EXEC; } static uint8_t getAbiVersion() { // MIPS non-PIC executable gets ABI version 1. if (Config->EMachine == EM_MIPS && getELFType() == ET_EXEC && (Config->EFlags & (EF_MIPS_PIC | EF_MIPS_CPIC)) == EF_MIPS_CPIC) return 1; return 0; } template void Writer::writeHeader() { uint8_t *Buf = Buffer->getBufferStart(); // For executable segments, the trap instructions are written before writing // the header. Setting Elf header bytes to zero ensures that any unused bytes // in header are zero-cleared, instead of having trap instructions. memset(Buf, 0, sizeof(Elf_Ehdr)); memcpy(Buf, "\177ELF", 4); // Write the ELF header. auto *EHdr = reinterpret_cast(Buf); EHdr->e_ident[EI_CLASS] = Config->Is64 ? ELFCLASS64 : ELFCLASS32; EHdr->e_ident[EI_DATA] = Config->IsLE ? ELFDATA2LSB : ELFDATA2MSB; EHdr->e_ident[EI_VERSION] = EV_CURRENT; EHdr->e_ident[EI_OSABI] = Config->OSABI; EHdr->e_ident[EI_ABIVERSION] = getAbiVersion(); EHdr->e_type = getELFType(); EHdr->e_machine = Config->EMachine; EHdr->e_version = EV_CURRENT; EHdr->e_entry = getEntryAddr(); EHdr->e_shoff = SectionHeaderOff; EHdr->e_flags = Config->EFlags; EHdr->e_ehsize = sizeof(Elf_Ehdr); EHdr->e_phnum = Phdrs.size(); EHdr->e_shentsize = sizeof(Elf_Shdr); if (!Config->Relocatable) { EHdr->e_phoff = sizeof(Elf_Ehdr); EHdr->e_phentsize = sizeof(Elf_Phdr); } // Write the program header table. auto *HBuf = reinterpret_cast(Buf + EHdr->e_phoff); for (PhdrEntry *P : Phdrs) { HBuf->p_type = P->p_type; HBuf->p_flags = P->p_flags; HBuf->p_offset = P->p_offset; HBuf->p_vaddr = P->p_vaddr; HBuf->p_paddr = P->p_paddr; HBuf->p_filesz = P->p_filesz; HBuf->p_memsz = P->p_memsz; HBuf->p_align = P->p_align; ++HBuf; } // Write the section header table. // // The ELF header can only store numbers up to SHN_LORESERVE in the e_shnum // and e_shstrndx fields. When the value of one of these fields exceeds // SHN_LORESERVE ELF requires us to put sentinel values in the ELF header and // use fields in the section header at index 0 to store // the value. The sentinel values and fields are: // e_shnum = 0, SHdrs[0].sh_size = number of sections. // e_shstrndx = SHN_XINDEX, SHdrs[0].sh_link = .shstrtab section index. auto *SHdrs = reinterpret_cast(Buf + EHdr->e_shoff); size_t Num = OutputSections.size() + 1; if (Num >= SHN_LORESERVE) SHdrs->sh_size = Num; else EHdr->e_shnum = Num; uint32_t StrTabIndex = InX::ShStrTab->getParent()->SectionIndex; if (StrTabIndex >= SHN_LORESERVE) { SHdrs->sh_link = StrTabIndex; EHdr->e_shstrndx = SHN_XINDEX; } else { EHdr->e_shstrndx = StrTabIndex; } for (OutputSection *Sec : OutputSections) Sec->writeHeaderTo(++SHdrs); } // Open a result file. template void Writer::openFile() { if (!Config->Is64 && FileSize > UINT32_MAX) { error("output file too large: " + Twine(FileSize) + " bytes"); return; } unlinkAsync(Config->OutputFile); unsigned Flags = 0; if (!Config->Relocatable) Flags = FileOutputBuffer::F_executable; Expected> BufferOrErr = FileOutputBuffer::create(Config->OutputFile, FileSize, Flags); if (!BufferOrErr) error("failed to open " + Config->OutputFile + ": " + llvm::toString(BufferOrErr.takeError())); else Buffer = std::move(*BufferOrErr); } template void Writer::writeSectionsBinary() { uint8_t *Buf = Buffer->getBufferStart(); for (OutputSection *Sec : OutputSections) if (Sec->Flags & SHF_ALLOC) Sec->writeTo(Buf + Sec->Offset); } static void fillTrap(uint8_t *I, uint8_t *End) { for (; I + 4 <= End; I += 4) memcpy(I, &Target->TrapInstr, 4); } // Fill the last page of executable segments with trap instructions // instead of leaving them as zero. Even though it is not required by any // standard, it is in general a good thing to do for security reasons. // // We'll leave other pages in segments as-is because the rest will be // overwritten by output sections. template void Writer::writeTrapInstr() { if (Script->HasSectionsCommand) return; // Fill the last page. uint8_t *Buf = Buffer->getBufferStart(); for (PhdrEntry *P : Phdrs) if (P->p_type == PT_LOAD && (P->p_flags & PF_X)) fillTrap(Buf + alignDown(P->p_offset + P->p_filesz, Target->PageSize), Buf + alignTo(P->p_offset + P->p_filesz, Target->PageSize)); // Round up the file size of the last segment to the page boundary iff it is // an executable segment to ensure that other tools don't accidentally // trim the instruction padding (e.g. when stripping the file). PhdrEntry *Last = nullptr; for (PhdrEntry *P : Phdrs) if (P->p_type == PT_LOAD) Last = P; if (Last && (Last->p_flags & PF_X)) Last->p_memsz = Last->p_filesz = alignTo(Last->p_filesz, Target->PageSize); } // Write section contents to a mmap'ed file. template void Writer::writeSections() { uint8_t *Buf = Buffer->getBufferStart(); OutputSection *EhFrameHdr = nullptr; if (InX::EhFrameHdr && !InX::EhFrameHdr->empty()) EhFrameHdr = InX::EhFrameHdr->getParent(); // In -r or -emit-relocs mode, write the relocation sections first as in // ELf_Rel targets we might find out that we need to modify the relocated // section while doing it. for (OutputSection *Sec : OutputSections) if (Sec->Type == SHT_REL || Sec->Type == SHT_RELA) Sec->writeTo(Buf + Sec->Offset); for (OutputSection *Sec : OutputSections) if (Sec != EhFrameHdr && Sec->Type != SHT_REL && Sec->Type != SHT_RELA) Sec->writeTo(Buf + Sec->Offset); // The .eh_frame_hdr depends on .eh_frame section contents, therefore // it should be written after .eh_frame is written. if (EhFrameHdr) EhFrameHdr->writeTo(Buf + EhFrameHdr->Offset); } template void Writer::writeBuildId() { if (!InX::BuildId || !InX::BuildId->getParent()) return; // Compute a hash of all sections of the output file. uint8_t *Start = Buffer->getBufferStart(); uint8_t *End = Start + FileSize; InX::BuildId->writeBuildId({Start, End}); } template void elf::writeResult(); template void elf::writeResult(); template void elf::writeResult(); template void elf::writeResult(); Index: vendor/lld/dist-release_70/test/COFF/arm64-localimport-align.s =================================================================== --- vendor/lld/dist-release_70/test/COFF/arm64-localimport-align.s (nonexistent) +++ vendor/lld/dist-release_70/test/COFF/arm64-localimport-align.s (revision 340122) @@ -0,0 +1,24 @@ +// REQUIRES: aarch64 +// RUN: llvm-mc -filetype=obj -triple=aarch64-windows %s -o %t.obj +// RUN: lld-link -entry:main -subsystem:console %t.obj -out:%t.exe +// Don't check the output, just make sure it links fine and doesn't +// error out due to a misaligned load. + .text + .globl main + .globl myfunc +main: + adrp x8, __imp_myfunc + ldr x0, [x8, :lo12:__imp_myfunc] + br x0 + ret +myfunc: + ret + + .section .rdata, "dr" + // Start the .rdata section with a 4 byte chunk, to expose the alignment + // of the next chunk in the section. +mydata: + .byte 42 + // The synthesized LocalImportChunk gets stored here in the .rdata + // section, but needs to get proper 8 byte alignment since it is a + // pointer, just like regular LookupChunks in the IAT. Property changes on: vendor/lld/dist-release_70/test/COFF/arm64-localimport-align.s ___________________________________________________________________ Added: svn:eol-style ## -0,0 +1 ## +native \ No newline at end of property Added: svn:keywords ## -0,0 +1 ## +FreeBSD=%H \ No newline at end of property Added: svn:mime-type ## -0,0 +1 ## +text/plain \ No newline at end of property Index: vendor/lld/dist-release_70/test/ELF/linkerscript/memory-include.test =================================================================== --- vendor/lld/dist-release_70/test/ELF/linkerscript/memory-include.test (nonexistent) +++ vendor/lld/dist-release_70/test/ELF/linkerscript/memory-include.test (revision 340122) @@ -0,0 +1,23 @@ +# REQUIRES: x86 + +# RUN: echo '.section .text,"ax"; .global _start; nop' > %t.s +# RUN: echo '.section .data,"aw"; .quad 0' >> %t.s +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o + +# RUN: echo "RAM2 (rwx): ORIGIN = 0x3000, LENGTH = 0x100" > %t.inc +# RUN: ld.lld -o %t.elf --script %s %t.o -L %T +# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s +# CHECK: .data 00000008 0000000000002000 DATA +# CHECK: .data2 00000008 0000000000003000 DATA + +MEMORY { + ROM (rwx): ORIGIN = 0x1000, LENGTH = 0x100 + RAM (rwx): ORIGIN = 0x2000, LENGTH = 0x100 + INCLUDE "memory-include.test.tmp.inc" +} + +SECTIONS { + .text : { *(.text*) } > ROM + .data : { *(.data*) } > RAM + .data2 : { QUAD(0) } > RAM2 +} Index: vendor/lld/dist-release_70/test/ELF/linkerscript/output-section-include.test =================================================================== --- vendor/lld/dist-release_70/test/ELF/linkerscript/output-section-include.test (nonexistent) +++ vendor/lld/dist-release_70/test/ELF/linkerscript/output-section-include.test (revision 340122) @@ -0,0 +1,30 @@ +# REQUIRES: x86 + +# RUN: echo '.section .text,"ax"; .global _start; nop' > %t.s +# RUN: echo '.section .data,"aw"; .quad 0' >> %t.s +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o + +## Empty include file. +# RUN: echo "" > %t.inc +# RUN: ld.lld -o %t.elf --script %s %t.o -L %T +# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK1 +# CHECK1: .data 00000008 0000000000002000 DATA + +## Non-empty include file. +# RUN: echo "QUAD(0)" > %t.inc +# RUN: ld.lld -o %t.elf --script %s %t.o -L %T +# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK2 +# CHECK2: .data 00000010 0000000000002000 DATA + +MEMORY { + ROM (rwx): ORIGIN = 0x1000, LENGTH = 0x100 + RAM (rwx): ORIGIN = 0x2000, LENGTH = 0x100 +} + +SECTIONS { + .text : { *(.text*) } > ROM + .data : { + *(.data*) + INCLUDE "output-section-include.test.tmp.inc" + } > RAM +} Index: vendor/lld/dist-release_70/test/ELF/linkerscript/section-include.test =================================================================== --- vendor/lld/dist-release_70/test/ELF/linkerscript/section-include.test (nonexistent) +++ vendor/lld/dist-release_70/test/ELF/linkerscript/section-include.test (revision 340122) @@ -0,0 +1,32 @@ +# REQUIRES: x86 + +# RUN: echo '.section .text,"ax"; .global _start; nop' > %t.s +# RUN: echo '.section .data,"aw"; .quad 0' >> %t.s +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o + +## Empty include file. +# RUN: echo "" > %t.inc +# RUN: ld.lld -o %t.elf --script %s %t.o -L %T +# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK1 +# CHECK1: .data 00000008 0000000000002000 DATA +# CHECK1-NEXT: .data3 00000008 0000000000002008 DATA + +## Non-empty include file. +# RUN: echo ".data2 : { QUAD(0) } > RAM" > %t.inc +# RUN: ld.lld -o %t.elf --script %s %t.o -L %T +# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK2 +# CHECK2: .data 00000008 0000000000002000 DATA +# CHECK2-NEXT: .data2 00000008 0000000000002008 DATA +# CHECK2-NEXT: .data3 00000008 0000000000002010 DATA + +MEMORY { + ROM (rwx): ORIGIN = 0x1000, LENGTH = 0x100 + RAM (rwx): ORIGIN = 0x2000, LENGTH = 0x100 +} + +SECTIONS { + .text : { *(.text*) } > ROM + .data : { *(.data*) } > RAM + INCLUDE "section-include.test.tmp.inc" + .data3 : { QUAD(0) } > RAM +} Index: vendor/lld/dist-release_70/test/ELF/local-ver-preemptible.s =================================================================== --- vendor/lld/dist-release_70/test/ELF/local-ver-preemptible.s (nonexistent) +++ vendor/lld/dist-release_70/test/ELF/local-ver-preemptible.s (revision 340122) @@ -0,0 +1,22 @@ +# REQUIRES: x86 +# RUN: echo '.global foo; .type foo, @function; foo:' | \ +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux - -o %t.so.o +# RUN: ld.lld %t.so.o -o %t.so -shared + +# RUN: echo "{ global: main; local: *; };" > %t.script + +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o +# RUN: ld.lld %t.o %t.so -o %t -version-script %t.script +# RUN: llvm-readelf -r --symbols %t | FileCheck %s + +# CHECK: Relocation section '.rela.plt' at offset {{.*}} contains 1 entries: +# CHECK: R_X86_64_JUMP_SLOT 0000000000201020 foo + 0 + +# CHECK: Symbol table '.dynsym' contains 2 entries: +# CHECK-NEXT: Num: Value Size Type Bind Vis Ndx Name +# CHECK-NEXT: 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND @ +# CHECK-NEXT: 1: 0000000000201020 0 FUNC GLOBAL DEFAULT UND foo@ + +.globl _start +_start: + movl $foo - ., %eax Property changes on: vendor/lld/dist-release_70/test/ELF/local-ver-preemptible.s ___________________________________________________________________ Added: svn:eol-style ## -0,0 +1 ## +native \ No newline at end of property Added: svn:keywords ## -0,0 +1 ## +FreeBSD=%H \ No newline at end of property Added: svn:mime-type ## -0,0 +1 ## +text/plain \ No newline at end of property Index: vendor/lld/dist-release_70/test/ELF/relocatable-rel-iplt.s =================================================================== --- vendor/lld/dist-release_70/test/ELF/relocatable-rel-iplt.s (nonexistent) +++ vendor/lld/dist-release_70/test/ELF/relocatable-rel-iplt.s (revision 340122) @@ -0,0 +1,56 @@ +# REQUIRES: x86 +# RUN: llvm-mc -filetype=obj -triple=i686-- %s -o %t1.o +# RUN: ld.lld -r %t1.o -o %t2.o +# RUN: llvm-readobj -t %t2.o | FileCheck %s + +// CHECK: Symbols [ +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: (0) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Local (0x0) +// CHECK-NEXT: Type: None (0x0) +// CHECK-NEXT: Other: 0 +// CHECK-NEXT: Section: Undefined (0x0) +// CHECK-NEXT: } +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: (0) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Local (0x0) +// CHECK-NEXT: Type: Section (0x3) +// CHECK-NEXT: Other: 0 +// CHECK-NEXT: Section: .text (0x1) +// CHECK-NEXT: } +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: __rel_iplt_end (1) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Weak (0x2) +// CHECK-NEXT: Type: None (0x0) +// CHECK-NEXT: Other [ (0x2) +// CHECK-NEXT: STV_HIDDEN (0x2) +// CHECK-NEXT: ] +// CHECK-NEXT: Section: Undefined (0x0) +// CHECK-NEXT: } +// CHECK-NEXT: Symbol { +// CHECK-NEXT: Name: __rel_iplt_start (16) +// CHECK-NEXT: Value: 0x0 +// CHECK-NEXT: Size: 0 +// CHECK-NEXT: Binding: Weak (0x2) +// CHECK-NEXT: Type: None (0x0) +// CHECK-NEXT: Other [ (0x2) +// CHECK-NEXT: STV_HIDDEN (0x2) +// CHECK-NEXT: ] +// CHECK-NEXT: Section: Undefined (0x0) +// CHECK-NEXT: } +// CHECK-NEXT: ] + + movl __rel_iplt_start, %eax + movl __rel_iplt_end, %eax + ret + + .hidden __rel_iplt_start + .hidden __rel_iplt_end + .weak __rel_iplt_start + .weak __rel_iplt_end Property changes on: vendor/lld/dist-release_70/test/ELF/relocatable-rel-iplt.s ___________________________________________________________________ Added: svn:eol-style ## -0,0 +1 ## +native \ No newline at end of property Added: svn:keywords ## -0,0 +1 ## +FreeBSD=%H \ No newline at end of property Added: svn:mime-type ## -0,0 +1 ## +text/plain \ No newline at end of property