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-rw-r--r--contrib/llvm/lib/MC/WinCOFFObjectWriter.cpp811
1 files changed, 401 insertions, 410 deletions
diff --git a/contrib/llvm/lib/MC/WinCOFFObjectWriter.cpp b/contrib/llvm/lib/MC/WinCOFFObjectWriter.cpp
index afc5c6a..956ae70 100644
--- a/contrib/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/contrib/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -1,4 +1,4 @@
-//===-- llvm/MC/WinCOFFObjectWriter.cpp -------------------------*- C++ -*-===//
+//===- llvm/MC/WinCOFFObjectWriter.cpp ------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
@@ -11,38 +11,51 @@
//
//===----------------------------------------------------------------------===//
-#include "llvm/MC/MCWinCOFFObjectWriter.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
-#include "llvm/Config/config.h"
+#include "llvm/BinaryFormat/COFF.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
-#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCFixup.h"
+#include "llvm/MC/MCFragment.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionCOFF.h"
+#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCSymbolCOFF.h"
#include "llvm/MC/MCValue.h"
+#include "llvm/MC/MCWinCOFFObjectWriter.h"
#include "llvm/MC/StringTableBuilder.h"
-#include "llvm/Support/COFF.h"
-#include "llvm/Support/Debug.h"
+#include "llvm/Support/Casting.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/JamCRC.h"
-#include <cstdio>
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
#include <ctime>
+#include <memory>
+#include <string>
+#include <vector>
using namespace llvm;
+using llvm::support::endian::write32le;
#define DEBUG_TYPE "WinCOFFObjectWriter"
namespace {
-typedef SmallString<COFF::NameSize> name;
+
+using name = SmallString<COFF::NameSize>;
enum AuxiliaryType {
ATFunctionDefinition,
@@ -57,25 +70,24 @@ struct AuxSymbol {
COFF::Auxiliary Aux;
};
-class COFFSymbol;
class COFFSection;
class COFFSymbol {
public:
- COFF::symbol Data;
+ COFF::symbol Data = {};
- typedef SmallVector<AuxSymbol, 1> AuxiliarySymbols;
+ using AuxiliarySymbols = SmallVector<AuxSymbol, 1>;
name Name;
int Index;
AuxiliarySymbols Aux;
- COFFSymbol *Other;
- COFFSection *Section;
- int Relocations;
+ COFFSymbol *Other = nullptr;
+ COFFSection *Section = nullptr;
+ int Relocations = 0;
+ const MCSymbol *MC = nullptr;
- const MCSymbol *MC;
+ COFFSymbol(StringRef Name) : Name(Name) {}
- COFFSymbol(StringRef name);
void set_name_offset(uint32_t Offset);
int64_t getIndex() const { return Index; }
@@ -89,39 +101,40 @@ public:
// This class contains staging data for a COFF relocation entry.
struct COFFRelocation {
COFF::relocation Data;
- COFFSymbol *Symb;
+ COFFSymbol *Symb = nullptr;
+
+ COFFRelocation() = default;
- COFFRelocation() : Symb(nullptr) {}
static size_t size() { return COFF::RelocationSize; }
};
-typedef std::vector<COFFRelocation> relocations;
+using relocations = std::vector<COFFRelocation>;
class COFFSection {
public:
- COFF::section Header;
+ COFF::section Header = {};
std::string Name;
int Number;
- MCSectionCOFF const *MCSection;
- COFFSymbol *Symbol;
+ MCSectionCOFF const *MCSection = nullptr;
+ COFFSymbol *Symbol = nullptr;
relocations Relocations;
- COFFSection(StringRef name);
+ COFFSection(StringRef Name) : Name(Name) {}
};
class WinCOFFObjectWriter : public MCObjectWriter {
public:
- typedef std::vector<std::unique_ptr<COFFSymbol>> symbols;
- typedef std::vector<std::unique_ptr<COFFSection>> sections;
+ using symbols = std::vector<std::unique_ptr<COFFSymbol>>;
+ using sections = std::vector<std::unique_ptr<COFFSection>>;
- typedef DenseMap<MCSymbol const *, COFFSymbol *> symbol_map;
- typedef DenseMap<MCSection const *, COFFSection *> section_map;
+ using symbol_map = DenseMap<MCSymbol const *, COFFSymbol *>;
+ using section_map = DenseMap<MCSection const *, COFFSection *>;
std::unique_ptr<MCWinCOFFObjectTargetWriter> TargetObjectWriter;
// Root level file contents.
- COFF::header Header;
+ COFF::header Header = {};
sections Sections;
symbols Symbols;
StringTableBuilder Strings{StringTableBuilder::WinCOFF};
@@ -149,9 +162,6 @@ public:
COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol *Symbol);
COFFSection *createSection(StringRef Name);
- template <typename object_t, typename list_t>
- object_t *createCOFFEntity(StringRef Name, list_t &List);
-
void defineSection(MCSectionCOFF const &Sec);
COFFSymbol *getLinkedSymbol(const MCSymbol &Symbol);
@@ -168,8 +178,12 @@ public:
void WriteFileHeader(const COFF::header &Header);
void WriteSymbol(const COFFSymbol &S);
void WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols &S);
- void writeSectionHeader(const COFF::section &S);
+ void writeSectionHeaders();
void WriteRelocation(const COFF::relocation &R);
+ uint32_t writeSectionContents(MCAssembler &Asm, const MCAsmLayout &Layout,
+ const MCSection &MCSec);
+ void writeSection(MCAssembler &Asm, const MCAsmLayout &Layout,
+ const COFFSection &Sec, const MCSection &MCSec);
// MCObjectWriter interface implementation.
@@ -181,45 +195,28 @@ public:
const MCFragment &FB, bool InSet,
bool IsPCRel) const override;
- bool isWeak(const MCSymbol &Sym) const override;
-
void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment, const MCFixup &Fixup,
- MCValue Target, bool &IsPCRel,
- uint64_t &FixedValue) override;
+ MCValue Target, uint64_t &FixedValue) override;
+
+ void createFileSymbols(MCAssembler &Asm);
+ void assignSectionNumbers();
+ void assignFileOffsets(MCAssembler &Asm, const MCAsmLayout &Layout);
void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
};
-}
-static inline void write_uint32_le(void *Data, uint32_t Value) {
- support::endian::write<uint32_t, support::little, support::unaligned>(Data,
- Value);
-}
+} // end anonymous namespace
//------------------------------------------------------------------------------
// Symbol class implementation
-COFFSymbol::COFFSymbol(StringRef name)
- : Name(name.begin(), name.end()), Other(nullptr), Section(nullptr),
- Relocations(0), MC(nullptr) {
- memset(&Data, 0, sizeof(Data));
-}
-
// In the case that the name does not fit within 8 bytes, the offset
// into the string table is stored in the last 4 bytes instead, leaving
// the first 4 bytes as 0.
void COFFSymbol::set_name_offset(uint32_t Offset) {
- write_uint32_le(Data.Name + 0, 0);
- write_uint32_le(Data.Name + 4, Offset);
-}
-
-//------------------------------------------------------------------------------
-// Section class implementation
-
-COFFSection::COFFSection(StringRef name)
- : Name(name), MCSection(nullptr), Symbol(nullptr) {
- memset(&Header, 0, sizeof(Header));
+ write32le(Data.Name + 0, 0);
+ write32le(Data.Name + 4, Offset);
}
//------------------------------------------------------------------------------
@@ -228,115 +225,92 @@ COFFSection::COFFSection(StringRef name)
WinCOFFObjectWriter::WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW,
raw_pwrite_stream &OS)
: MCObjectWriter(OS, true), TargetObjectWriter(MOTW) {
- memset(&Header, 0, sizeof(Header));
-
Header.Machine = TargetObjectWriter->getMachine();
}
COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
- return createCOFFEntity<COFFSymbol>(Name, Symbols);
+ Symbols.push_back(make_unique<COFFSymbol>(Name));
+ return Symbols.back().get();
}
COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol *Symbol) {
- symbol_map::iterator i = SymbolMap.find(Symbol);
- if (i != SymbolMap.end())
- return i->second;
- COFFSymbol *RetSymbol =
- createCOFFEntity<COFFSymbol>(Symbol->getName(), Symbols);
- SymbolMap[Symbol] = RetSymbol;
- return RetSymbol;
+ COFFSymbol *&Ret = SymbolMap[Symbol];
+ if (!Ret)
+ Ret = createSymbol(Symbol->getName());
+ return Ret;
}
COFFSection *WinCOFFObjectWriter::createSection(StringRef Name) {
- return createCOFFEntity<COFFSection>(Name, Sections);
+ Sections.emplace_back(make_unique<COFFSection>(Name));
+ return Sections.back().get();
}
-/// A template used to lookup or create a symbol/section, and initialize it if
-/// needed.
-template <typename object_t, typename list_t>
-object_t *WinCOFFObjectWriter::createCOFFEntity(StringRef Name, list_t &List) {
- List.push_back(make_unique<object_t>(Name));
-
- return List.back().get();
-}
-
-/// This function takes a section data object from the assembler
-/// and creates the associated COFF section staging object.
-void WinCOFFObjectWriter::defineSection(MCSectionCOFF const &Sec) {
- COFFSection *coff_section = createSection(Sec.getSectionName());
- COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
- if (Sec.getSelection() != COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) {
- if (const MCSymbol *S = Sec.getCOMDATSymbol()) {
- COFFSymbol *COMDATSymbol = GetOrCreateCOFFSymbol(S);
- if (COMDATSymbol->Section)
- report_fatal_error("two sections have the same comdat");
- COMDATSymbol->Section = coff_section;
- }
- }
-
- coff_section->Symbol = coff_symbol;
- coff_symbol->Section = coff_section;
- coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
-
- // In this case the auxiliary symbol is a Section Definition.
- coff_symbol->Aux.resize(1);
- memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
- coff_symbol->Aux[0].AuxType = ATSectionDefinition;
- coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
-
- coff_section->Header.Characteristics = Sec.getCharacteristics();
-
- uint32_t &Characteristics = coff_section->Header.Characteristics;
+static uint32_t getAlignment(const MCSectionCOFF &Sec) {
switch (Sec.getAlignment()) {
case 1:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_1BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_1BYTES;
case 2:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_2BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_2BYTES;
case 4:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_4BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_4BYTES;
case 8:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_8BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_8BYTES;
case 16:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_16BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_16BYTES;
case 32:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_32BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_32BYTES;
case 64:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_64BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_64BYTES;
case 128:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_128BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_128BYTES;
case 256:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_256BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_256BYTES;
case 512:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_512BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_512BYTES;
case 1024:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_1024BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_1024BYTES;
case 2048:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_2048BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_2048BYTES;
case 4096:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_4096BYTES;
- break;
+ return COFF::IMAGE_SCN_ALIGN_4096BYTES;
case 8192:
- Characteristics |= COFF::IMAGE_SCN_ALIGN_8192BYTES;
- break;
- default:
- llvm_unreachable("unsupported section alignment");
+ return COFF::IMAGE_SCN_ALIGN_8192BYTES;
+ }
+ llvm_unreachable("unsupported section alignment");
+}
+
+/// This function takes a section data object from the assembler
+/// and creates the associated COFF section staging object.
+void WinCOFFObjectWriter::defineSection(const MCSectionCOFF &MCSec) {
+ COFFSection *Section = createSection(MCSec.getSectionName());
+ COFFSymbol *Symbol = createSymbol(MCSec.getSectionName());
+ Section->Symbol = Symbol;
+ Symbol->Section = Section;
+ Symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
+
+ // Create a COMDAT symbol if needed.
+ if (MCSec.getSelection() != COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) {
+ if (const MCSymbol *S = MCSec.getCOMDATSymbol()) {
+ COFFSymbol *COMDATSymbol = GetOrCreateCOFFSymbol(S);
+ if (COMDATSymbol->Section)
+ report_fatal_error("two sections have the same comdat");
+ COMDATSymbol->Section = Section;
+ }
}
+ // In this case the auxiliary symbol is a Section Definition.
+ Symbol->Aux.resize(1);
+ Symbol->Aux[0] = {};
+ Symbol->Aux[0].AuxType = ATSectionDefinition;
+ Symbol->Aux[0].Aux.SectionDefinition.Selection = MCSec.getSelection();
+
+ // Set section alignment.
+ Section->Header.Characteristics = MCSec.getCharacteristics();
+ Section->Header.Characteristics |= getAlignment(MCSec);
+
// Bind internal COFF section to MC section.
- coff_section->MCSection = &Sec;
- SectionMap[&Sec] = coff_section;
+ Section->MCSection = &MCSec;
+ SectionMap[&MCSec] = Section;
}
static uint64_t getSymbolValue(const MCSymbol &Symbol,
@@ -368,25 +342,25 @@ COFFSymbol *WinCOFFObjectWriter::getLinkedSymbol(const MCSymbol &Symbol) {
/// This function takes a symbol data object from the assembler
/// and creates the associated COFF symbol staging object.
-void WinCOFFObjectWriter::DefineSymbol(const MCSymbol &Symbol,
+void WinCOFFObjectWriter::DefineSymbol(const MCSymbol &MCSym,
MCAssembler &Assembler,
const MCAsmLayout &Layout) {
- COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&Symbol);
- const MCSymbol *Base = Layout.getBaseSymbol(Symbol);
+ COFFSymbol *Sym = GetOrCreateCOFFSymbol(&MCSym);
+ const MCSymbol *Base = Layout.getBaseSymbol(MCSym);
COFFSection *Sec = nullptr;
if (Base && Base->getFragment()) {
Sec = SectionMap[Base->getFragment()->getParent()];
- if (coff_symbol->Section && coff_symbol->Section != Sec)
+ if (Sym->Section && Sym->Section != Sec)
report_fatal_error("conflicting sections for symbol");
}
COFFSymbol *Local = nullptr;
- if (cast<MCSymbolCOFF>(Symbol).isWeakExternal()) {
- coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
+ if (cast<MCSymbolCOFF>(MCSym).isWeakExternal()) {
+ Sym->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
- COFFSymbol *WeakDefault = getLinkedSymbol(Symbol);
+ COFFSymbol *WeakDefault = getLinkedSymbol(MCSym);
if (!WeakDefault) {
- std::string WeakName = (".weak." + Symbol.getName() + ".default").str();
+ std::string WeakName = (".weak." + MCSym.getName() + ".default").str();
WeakDefault = createSymbol(WeakName);
if (!Sec)
WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
@@ -395,41 +369,41 @@ void WinCOFFObjectWriter::DefineSymbol(const MCSymbol &Symbol,
Local = WeakDefault;
}
- coff_symbol->Other = WeakDefault;
+ Sym->Other = WeakDefault;
// Setup the Weak External auxiliary symbol.
- coff_symbol->Aux.resize(1);
- memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
- coff_symbol->Aux[0].AuxType = ATWeakExternal;
- coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
- coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
+ Sym->Aux.resize(1);
+ memset(&Sym->Aux[0], 0, sizeof(Sym->Aux[0]));
+ Sym->Aux[0].AuxType = ATWeakExternal;
+ Sym->Aux[0].Aux.WeakExternal.TagIndex = 0;
+ Sym->Aux[0].Aux.WeakExternal.Characteristics =
COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
} else {
if (!Base)
- coff_symbol->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
+ Sym->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
else
- coff_symbol->Section = Sec;
- Local = coff_symbol;
+ Sym->Section = Sec;
+ Local = Sym;
}
if (Local) {
- Local->Data.Value = getSymbolValue(Symbol, Layout);
+ Local->Data.Value = getSymbolValue(MCSym, Layout);
- const MCSymbolCOFF &SymbolCOFF = cast<MCSymbolCOFF>(Symbol);
+ const MCSymbolCOFF &SymbolCOFF = cast<MCSymbolCOFF>(MCSym);
Local->Data.Type = SymbolCOFF.getType();
Local->Data.StorageClass = SymbolCOFF.getClass();
// If no storage class was specified in the streamer, define it here.
if (Local->Data.StorageClass == COFF::IMAGE_SYM_CLASS_NULL) {
- bool IsExternal = Symbol.isExternal() ||
- (!Symbol.getFragment() && !Symbol.isVariable());
+ bool IsExternal = MCSym.isExternal() ||
+ (!MCSym.getFragment() && !MCSym.isVariable());
Local->Data.StorageClass = IsExternal ? COFF::IMAGE_SYM_CLASS_EXTERNAL
: COFF::IMAGE_SYM_CLASS_STATIC;
}
}
- coff_symbol->MC = &Symbol;
+ Sym->MC = &MCSym;
}
// Maximum offsets for different string table entry encodings.
@@ -459,24 +433,25 @@ static void encodeBase64StringEntry(char *Buffer, uint64_t Value) {
}
void WinCOFFObjectWriter::SetSectionName(COFFSection &S) {
- if (S.Name.size() > COFF::NameSize) {
- uint64_t StringTableEntry = Strings.getOffset(S.Name);
-
- if (StringTableEntry <= Max7DecimalOffset) {
- SmallVector<char, COFF::NameSize> Buffer;
- Twine('/').concat(Twine(StringTableEntry)).toVector(Buffer);
- assert(Buffer.size() <= COFF::NameSize && Buffer.size() >= 2);
-
- std::memcpy(S.Header.Name, Buffer.data(), Buffer.size());
- } else if (StringTableEntry <= MaxBase64Offset) {
- // Starting with 10,000,000, offsets are encoded as base64.
- encodeBase64StringEntry(S.Header.Name, StringTableEntry);
- } else {
- report_fatal_error("COFF string table is greater than 64 GB.");
- }
- } else {
+ if (S.Name.size() <= COFF::NameSize) {
std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
+ return;
+ }
+
+ uint64_t StringTableEntry = Strings.getOffset(S.Name);
+ if (StringTableEntry <= Max7DecimalOffset) {
+ SmallVector<char, COFF::NameSize> Buffer;
+ Twine('/').concat(Twine(StringTableEntry)).toVector(Buffer);
+ assert(Buffer.size() <= COFF::NameSize && Buffer.size() >= 2);
+ std::memcpy(S.Header.Name, Buffer.data(), Buffer.size());
+ return;
}
+ if (StringTableEntry <= MaxBase64Offset) {
+ // Starting with 10,000,000, offsets are encoded as base64.
+ encodeBase64StringEntry(S.Header.Name, StringTableEntry);
+ return;
+ }
+ report_fatal_error("COFF string table is greater than 64 GB.");
}
void WinCOFFObjectWriter::SetSymbolName(COFFSymbol &S) {
@@ -583,18 +558,37 @@ void WinCOFFObjectWriter::WriteAuxiliarySymbols(
}
}
-void WinCOFFObjectWriter::writeSectionHeader(const COFF::section &S) {
- writeBytes(StringRef(S.Name, COFF::NameSize));
-
- writeLE32(S.VirtualSize);
- writeLE32(S.VirtualAddress);
- writeLE32(S.SizeOfRawData);
- writeLE32(S.PointerToRawData);
- writeLE32(S.PointerToRelocations);
- writeLE32(S.PointerToLineNumbers);
- writeLE16(S.NumberOfRelocations);
- writeLE16(S.NumberOfLineNumbers);
- writeLE32(S.Characteristics);
+// Write the section header.
+void WinCOFFObjectWriter::writeSectionHeaders() {
+ // Section numbers must be monotonically increasing in the section
+ // header, but our Sections array is not sorted by section number,
+ // so make a copy of Sections and sort it.
+ std::vector<COFFSection *> Arr;
+ for (auto &Section : Sections)
+ Arr.push_back(Section.get());
+ std::sort(Arr.begin(), Arr.end(),
+ [](const COFFSection *A, const COFFSection *B) {
+ return A->Number < B->Number;
+ });
+
+ for (auto &Section : Arr) {
+ if (Section->Number == -1)
+ continue;
+
+ COFF::section &S = Section->Header;
+ if (Section->Relocations.size() >= 0xffff)
+ S.Characteristics |= COFF::IMAGE_SCN_LNK_NRELOC_OVFL;
+ writeBytes(StringRef(S.Name, COFF::NameSize));
+ writeLE32(S.VirtualSize);
+ writeLE32(S.VirtualAddress);
+ writeLE32(S.SizeOfRawData);
+ writeLE32(S.PointerToRawData);
+ writeLE32(S.PointerToRelocations);
+ writeLE32(S.PointerToLineNumbers);
+ writeLE16(S.NumberOfRelocations);
+ writeLE16(S.NumberOfLineNumbers);
+ writeLE32(S.Characteristics);
+ }
}
void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
@@ -603,6 +597,87 @@ void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
writeLE16(R.Type);
}
+// Write MCSec's contents. What this function does is essentially
+// "Asm.writeSectionData(&MCSec, Layout)", but it's a bit complicated
+// because it needs to compute a CRC.
+uint32_t WinCOFFObjectWriter::writeSectionContents(MCAssembler &Asm,
+ const MCAsmLayout &Layout,
+ const MCSection &MCSec) {
+ // Save the contents of the section to a temporary buffer, we need this
+ // to CRC the data before we dump it into the object file.
+ SmallVector<char, 128> Buf;
+ raw_svector_ostream VecOS(Buf);
+ raw_pwrite_stream &OldStream = getStream();
+
+ // Redirect the output stream to our buffer and fill our buffer with
+ // the section data.
+ setStream(VecOS);
+ Asm.writeSectionData(&MCSec, Layout);
+
+ // Reset the stream back to what it was before.
+ setStream(OldStream);
+
+ // Write the section contents to the object file.
+ getStream() << Buf;
+
+ // Calculate our CRC with an initial value of '0', this is not how
+ // JamCRC is specified but it aligns with the expected output.
+ JamCRC JC(/*Init=*/0);
+ JC.update(Buf);
+ return JC.getCRC();
+}
+
+void WinCOFFObjectWriter::writeSection(MCAssembler &Asm,
+ const MCAsmLayout &Layout,
+ const COFFSection &Sec,
+ const MCSection &MCSec) {
+ if (Sec.Number == -1)
+ return;
+
+ // Write the section contents.
+ if (Sec.Header.PointerToRawData != 0) {
+ assert(getStream().tell() <= Sec.Header.PointerToRawData &&
+ "Section::PointerToRawData is insane!");
+
+ unsigned PaddingSize = Sec.Header.PointerToRawData - getStream().tell();
+ assert(PaddingSize < 4 &&
+ "Should only need at most three bytes of padding!");
+ WriteZeros(PaddingSize);
+
+ uint32_t CRC = writeSectionContents(Asm, Layout, MCSec);
+
+ // Update the section definition auxiliary symbol to record the CRC.
+ COFFSection *Sec = SectionMap[&MCSec];
+ COFFSymbol::AuxiliarySymbols &AuxSyms = Sec->Symbol->Aux;
+ assert(AuxSyms.size() == 1 && AuxSyms[0].AuxType == ATSectionDefinition);
+ AuxSymbol &SecDef = AuxSyms[0];
+ SecDef.Aux.SectionDefinition.CheckSum = CRC;
+ }
+
+ // Write relocations for this section.
+ if (Sec.Relocations.empty()) {
+ assert(Sec.Header.PointerToRelocations == 0 &&
+ "Section::PointerToRelocations is insane!");
+ return;
+ }
+
+ assert(getStream().tell() == Sec.Header.PointerToRelocations &&
+ "Section::PointerToRelocations is insane!");
+
+ if (Sec.Relocations.size() >= 0xffff) {
+ // In case of overflow, write actual relocation count as first
+ // relocation. Including the synthetic reloc itself (+ 1).
+ COFF::relocation R;
+ R.VirtualAddress = Sec.Relocations.size() + 1;
+ R.SymbolTableIndex = 0;
+ R.Type = 0;
+ WriteRelocation(R);
+ }
+
+ for (const auto &Relocation : Sec.Relocations)
+ WriteRelocation(Relocation.Data);
+}
+
////////////////////////////////////////////////////////////////////////////////
// MCObjectWriter interface implementations
@@ -632,26 +707,11 @@ bool WinCOFFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
InSet, IsPCRel);
}
-bool WinCOFFObjectWriter::isWeak(const MCSymbol &Sym) const {
- if (!Sym.isExternal())
- return false;
-
- if (!Sym.isInSection())
- return false;
-
- const auto &Sec = cast<MCSectionCOFF>(Sym.getSection());
- if (!Sec.getCOMDATSymbol())
- return false;
-
- // It looks like for COFF it is invalid to replace a reference to a global
- // in a comdat with a reference to a local.
- // FIXME: Add a specification reference if available.
- return true;
-}
-
-void WinCOFFObjectWriter::recordRelocation(
- MCAssembler &Asm, const MCAsmLayout &Layout, const MCFragment *Fragment,
- const MCFixup &Fixup, MCValue Target, bool &IsPCRel, uint64_t &FixedValue) {
+void WinCOFFObjectWriter::recordRelocation(MCAssembler &Asm,
+ const MCAsmLayout &Layout,
+ const MCFragment *Fragment,
+ const MCFixup &Fixup, MCValue Target,
+ uint64_t &FixedValue) {
assert(Target.getSymA() && "Relocation must reference a symbol!");
const MCSymbol &A = Target.getSymA()->getSymbol();
@@ -668,15 +728,14 @@ void WinCOFFObjectWriter::recordRelocation(
return;
}
- MCSection *Section = Fragment->getParent();
+ MCSection *MCSec = Fragment->getParent();
// Mark this symbol as requiring an entry in the symbol table.
- assert(SectionMap.find(Section) != SectionMap.end() &&
+ assert(SectionMap.find(MCSec) != SectionMap.end() &&
"Section must already have been defined in executePostLayoutBinding!");
- COFFSection *coff_section = SectionMap[Section];
+ COFFSection *Sec = SectionMap[MCSec];
const MCSymbolRefExpr *SymB = Target.getSymB();
- bool CrossSection = false;
if (SymB) {
const MCSymbol *B = &SymB->getSymbol();
@@ -688,28 +747,9 @@ void WinCOFFObjectWriter::recordRelocation(
return;
}
- if (!A.getFragment()) {
- Asm.getContext().reportError(
- Fixup.getLoc(),
- Twine("symbol '") + A.getName() +
- "' can not be undefined in a subtraction expression");
- return;
- }
-
- CrossSection = &A.getSection() != &B->getSection();
-
// Offset of the symbol in the section
int64_t OffsetOfB = Layout.getSymbolOffset(*B);
- // In the case where we have SymbA and SymB, we just need to store the delta
- // between the two symbols. Update FixedValue to account for the delta, and
- // skip recording the relocation.
- if (!CrossSection) {
- int64_t OffsetOfA = Layout.getSymbolOffset(A);
- FixedValue = (OffsetOfA - OffsetOfB) + Target.getConstant();
- return;
- }
-
// Offset of the relocation in the section
int64_t OffsetOfRelocation =
Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
@@ -725,7 +765,7 @@ void WinCOFFObjectWriter::recordRelocation(
Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
// Turn relocations for temporary symbols into section relocations.
- if (A.isTemporary() || CrossSection) {
+ if (A.isTemporary()) {
MCSection *TargetSection = &A.getSection();
assert(
SectionMap.find(TargetSection) != SectionMap.end() &&
@@ -743,7 +783,7 @@ void WinCOFFObjectWriter::recordRelocation(
Reloc.Data.VirtualAddress += Fixup.getOffset();
Reloc.Data.Type = TargetObjectWriter->getRelocType(
- Target, Fixup, CrossSection, Asm.getBackend());
+ Asm.getContext(), Target, Fixup, SymB, Asm.getBackend());
// FIXME: Can anyone explain what this does other than adjust for the size
// of the offset?
@@ -796,46 +836,31 @@ void WinCOFFObjectWriter::recordRelocation(
FixedValue = 0;
if (TargetObjectWriter->recordRelocation(Fixup))
- coff_section->Relocations.push_back(Reloc);
+ Sec->Relocations.push_back(Reloc);
}
-void WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
- const MCAsmLayout &Layout) {
- size_t SectionsSize = Sections.size();
- if (SectionsSize > static_cast<size_t>(INT32_MAX))
- report_fatal_error(
- "PE COFF object files can't have more than 2147483647 sections");
-
- // Assign symbol and section indexes and offsets.
- int32_t NumberOfSections = static_cast<int32_t>(SectionsSize);
-
- UseBigObj = NumberOfSections > COFF::MaxNumberOfSections16;
-
- // Assign section numbers.
- size_t Number = 1;
- for (const auto &Section : Sections) {
- Section->Number = Number;
- Section->Symbol->Data.SectionNumber = Number;
- Section->Symbol->Aux[0].Aux.SectionDefinition.Number = Number;
- ++Number;
- }
-
- Header.NumberOfSections = NumberOfSections;
- Header.NumberOfSymbols = 0;
+static std::time_t getTime() {
+ std::time_t Now = time(nullptr);
+ if (Now < 0 || !isUInt<32>(Now))
+ return UINT32_MAX;
+ return Now;
+}
+// Create .file symbols.
+void WinCOFFObjectWriter::createFileSymbols(MCAssembler &Asm) {
for (const std::string &Name : Asm.getFileNames()) {
// round up to calculate the number of auxiliary symbols required
unsigned SymbolSize = UseBigObj ? COFF::Symbol32Size : COFF::Symbol16Size;
unsigned Count = (Name.size() + SymbolSize - 1) / SymbolSize;
- COFFSymbol *file = createSymbol(".file");
- file->Data.SectionNumber = COFF::IMAGE_SYM_DEBUG;
- file->Data.StorageClass = COFF::IMAGE_SYM_CLASS_FILE;
- file->Aux.resize(Count);
+ COFFSymbol *File = createSymbol(".file");
+ File->Data.SectionNumber = COFF::IMAGE_SYM_DEBUG;
+ File->Data.StorageClass = COFF::IMAGE_SYM_CLASS_FILE;
+ File->Aux.resize(Count);
unsigned Offset = 0;
unsigned Length = Name.size();
- for (auto &Aux : file->Aux) {
+ for (auto &Aux : File->Aux) {
Aux.AuxType = ATFile;
if (Length > SymbolSize) {
@@ -850,6 +875,109 @@ void WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
Offset += SymbolSize;
}
}
+}
+
+static bool isAssociative(const COFFSection &Section) {
+ return Section.Symbol->Aux[0].Aux.SectionDefinition.Selection ==
+ COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE;
+}
+
+void WinCOFFObjectWriter::assignSectionNumbers() {
+ size_t I = 1;
+ auto Assign = [&](COFFSection &Section) {
+ Section.Number = I;
+ Section.Symbol->Data.SectionNumber = I;
+ Section.Symbol->Aux[0].Aux.SectionDefinition.Number = I;
+ ++I;
+ };
+
+ // Although it is not explicitly requested by the Microsoft COFF spec,
+ // we should avoid emitting forward associative section references,
+ // because MSVC link.exe as of 2017 cannot handle that.
+ for (const std::unique_ptr<COFFSection> &Section : Sections)
+ if (!isAssociative(*Section))
+ Assign(*Section);
+ for (const std::unique_ptr<COFFSection> &Section : Sections)
+ if (isAssociative(*Section))
+ Assign(*Section);
+}
+
+// Assign file offsets to COFF object file structures.
+void WinCOFFObjectWriter::assignFileOffsets(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
+ unsigned Offset = getInitialOffset();
+
+ Offset += UseBigObj ? COFF::Header32Size : COFF::Header16Size;
+ Offset += COFF::SectionSize * Header.NumberOfSections;
+
+ for (const auto &Section : Asm) {
+ COFFSection *Sec = SectionMap[&Section];
+
+ if (Sec->Number == -1)
+ continue;
+
+ Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(&Section);
+
+ if (IsPhysicalSection(Sec)) {
+ // Align the section data to a four byte boundary.
+ Offset = alignTo(Offset, 4);
+ Sec->Header.PointerToRawData = Offset;
+
+ Offset += Sec->Header.SizeOfRawData;
+ }
+
+ if (!Sec->Relocations.empty()) {
+ bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
+
+ if (RelocationsOverflow) {
+ // Signal overflow by setting NumberOfRelocations to max value. Actual
+ // size is found in reloc #0. Microsoft tools understand this.
+ Sec->Header.NumberOfRelocations = 0xffff;
+ } else {
+ Sec->Header.NumberOfRelocations = Sec->Relocations.size();
+ }
+ Sec->Header.PointerToRelocations = Offset;
+
+ if (RelocationsOverflow) {
+ // Reloc #0 will contain actual count, so make room for it.
+ Offset += COFF::RelocationSize;
+ }
+
+ Offset += COFF::RelocationSize * Sec->Relocations.size();
+
+ for (auto &Relocation : Sec->Relocations) {
+ assert(Relocation.Symb->getIndex() != -1);
+ Relocation.Data.SymbolTableIndex = Relocation.Symb->getIndex();
+ }
+ }
+
+ assert(Sec->Symbol->Aux.size() == 1 &&
+ "Section's symbol must have one aux!");
+ AuxSymbol &Aux = Sec->Symbol->Aux[0];
+ assert(Aux.AuxType == ATSectionDefinition &&
+ "Section's symbol's aux symbol must be a Section Definition!");
+ Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
+ Aux.Aux.SectionDefinition.NumberOfRelocations =
+ Sec->Header.NumberOfRelocations;
+ Aux.Aux.SectionDefinition.NumberOfLinenumbers =
+ Sec->Header.NumberOfLineNumbers;
+ }
+
+ Header.PointerToSymbolTable = Offset;
+}
+
+void WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
+ if (Sections.size() > INT32_MAX)
+ report_fatal_error(
+ "PE COFF object files can't have more than 2147483647 sections");
+
+ UseBigObj = Sections.size() > COFF::MaxNumberOfSections16;
+ Header.NumberOfSections = Sections.size();
+ Header.NumberOfSymbols = 0;
+
+ assignSectionNumbers();
+ createFileSymbols(Asm);
for (auto &Symbol : Symbols) {
// Update section number & offset for symbols that have them.
@@ -912,78 +1040,12 @@ void WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
Section->Symbol->Aux[0].Aux.SectionDefinition.Number = Assoc->Number;
}
- // Assign file offsets to COFF object file structures.
-
- unsigned offset = getInitialOffset();
-
- if (UseBigObj)
- offset += COFF::Header32Size;
- else
- offset += COFF::Header16Size;
- offset += COFF::SectionSize * Header.NumberOfSections;
-
- for (const auto &Section : Asm) {
- COFFSection *Sec = SectionMap[&Section];
-
- if (Sec->Number == -1)
- continue;
-
- Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(&Section);
-
- if (IsPhysicalSection(Sec)) {
- // Align the section data to a four byte boundary.
- offset = alignTo(offset, 4);
- Sec->Header.PointerToRawData = offset;
-
- offset += Sec->Header.SizeOfRawData;
- }
-
- if (Sec->Relocations.size() > 0) {
- bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
-
- if (RelocationsOverflow) {
- // Signal overflow by setting NumberOfRelocations to max value. Actual
- // size is found in reloc #0. Microsoft tools understand this.
- Sec->Header.NumberOfRelocations = 0xffff;
- } else {
- Sec->Header.NumberOfRelocations = Sec->Relocations.size();
- }
- Sec->Header.PointerToRelocations = offset;
-
- if (RelocationsOverflow) {
- // Reloc #0 will contain actual count, so make room for it.
- offset += COFF::RelocationSize;
- }
-
- offset += COFF::RelocationSize * Sec->Relocations.size();
-
- for (auto &Relocation : Sec->Relocations) {
- assert(Relocation.Symb->getIndex() != -1);
- Relocation.Data.SymbolTableIndex = Relocation.Symb->getIndex();
- }
- }
-
- assert(Sec->Symbol->Aux.size() == 1 &&
- "Section's symbol must have one aux!");
- AuxSymbol &Aux = Sec->Symbol->Aux[0];
- assert(Aux.AuxType == ATSectionDefinition &&
- "Section's symbol's aux symbol must be a Section Definition!");
- Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
- Aux.Aux.SectionDefinition.NumberOfRelocations =
- Sec->Header.NumberOfRelocations;
- Aux.Aux.SectionDefinition.NumberOfLinenumbers =
- Sec->Header.NumberOfLineNumbers;
- }
-
- Header.PointerToSymbolTable = offset;
+ assignFileOffsets(Asm, Layout);
// MS LINK expects to be able to use this timestamp to implement their
// /INCREMENTAL feature.
if (Asm.isIncrementalLinkerCompatible()) {
- std::time_t Now = time(nullptr);
- if (Now < 0 || !isUInt<32>(Now))
- Now = UINT32_MAX;
- Header.TimeDateStamp = Now;
+ Header.TimeDateStamp = getTime();
} else {
// Have deterministic output if /INCREMENTAL isn't needed. Also matches GNU.
Header.TimeDateStamp = 0;
@@ -991,96 +1053,25 @@ void WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
// Write it all to disk...
WriteFileHeader(Header);
+ writeSectionHeaders();
- {
- sections::iterator i, ie;
- MCAssembler::iterator j, je;
-
- for (auto &Section : Sections) {
- if (Section->Number != -1) {
- if (Section->Relocations.size() >= 0xffff)
- Section->Header.Characteristics |= COFF::IMAGE_SCN_LNK_NRELOC_OVFL;
- writeSectionHeader(Section->Header);
- }
- }
-
- SmallVector<char, 128> SectionContents;
- for (i = Sections.begin(), ie = Sections.end(), j = Asm.begin(),
- je = Asm.end();
- (i != ie) && (j != je); ++i, ++j) {
-
- if ((*i)->Number == -1)
- continue;
-
- if ((*i)->Header.PointerToRawData != 0) {
- assert(getStream().tell() <= (*i)->Header.PointerToRawData &&
- "Section::PointerToRawData is insane!");
-
- unsigned SectionDataPadding =
- (*i)->Header.PointerToRawData - getStream().tell();
- assert(SectionDataPadding < 4 &&
- "Should only need at most three bytes of padding!");
-
- WriteZeros(SectionDataPadding);
-
- // Save the contents of the section to a temporary buffer, we need this
- // to CRC the data before we dump it into the object file.
- SectionContents.clear();
- raw_svector_ostream VecOS(SectionContents);
- raw_pwrite_stream &OldStream = getStream();
- // Redirect the output stream to our buffer.
- setStream(VecOS);
- // Fill our buffer with the section data.
- Asm.writeSectionData(&*j, Layout);
- // Reset the stream back to what it was before.
- setStream(OldStream);
-
- // Calculate our CRC with an initial value of '0', this is not how
- // JamCRC is specified but it aligns with the expected output.
- JamCRC JC(/*Init=*/0x00000000U);
- JC.update(SectionContents);
-
- // Write the section contents to the object file.
- getStream() << SectionContents;
-
- // Update the section definition auxiliary symbol to record the CRC.
- COFFSection *Sec = SectionMap[&*j];
- COFFSymbol::AuxiliarySymbols &AuxSyms = Sec->Symbol->Aux;
- assert(AuxSyms.size() == 1 &&
- AuxSyms[0].AuxType == ATSectionDefinition);
- AuxSymbol &SecDef = AuxSyms[0];
- SecDef.Aux.SectionDefinition.CheckSum = JC.getCRC();
- }
-
- if ((*i)->Relocations.size() > 0) {
- assert(getStream().tell() == (*i)->Header.PointerToRelocations &&
- "Section::PointerToRelocations is insane!");
-
- if ((*i)->Relocations.size() >= 0xffff) {
- // In case of overflow, write actual relocation count as first
- // relocation. Including the synthetic reloc itself (+ 1).
- COFF::relocation r;
- r.VirtualAddress = (*i)->Relocations.size() + 1;
- r.SymbolTableIndex = 0;
- r.Type = 0;
- WriteRelocation(r);
- }
-
- for (const auto &Relocation : (*i)->Relocations)
- WriteRelocation(Relocation.Data);
- } else
- assert((*i)->Header.PointerToRelocations == 0 &&
- "Section::PointerToRelocations is insane!");
- }
- }
+ // Write section contents.
+ sections::iterator I = Sections.begin();
+ sections::iterator IE = Sections.end();
+ MCAssembler::iterator J = Asm.begin();
+ MCAssembler::iterator JE = Asm.end();
+ for (; I != IE && J != JE; ++I, ++J)
+ writeSection(Asm, Layout, **I, *J);
assert(getStream().tell() == Header.PointerToSymbolTable &&
"Header::PointerToSymbolTable is insane!");
+ // Write a symbol table.
for (auto &Symbol : Symbols)
if (Symbol->getIndex() != -1)
WriteSymbol(*Symbol);
+ // Write a string table, which completes the entire COFF file.
Strings.write(getStream());
}
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