//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "WinCOFFObjectWriter"
-
+#include "llvm/MC/MCWinCOFFObjectWriter.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/MC/MCAsmLayout.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
-#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCSectionCOFF.h"
#include "llvm/MC/MCSymbol.h"
-#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCValue.h"
-#include "llvm/MC/MCAssembler.h"
-#include "llvm/MC/MCAsmLayout.h"
-#include "llvm/MC/MCSectionCOFF.h"
-
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/StringMap.h"
-#include "llvm/ADT/StringRef.h"
-
#include "llvm/Support/COFF.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
-
+#include "llvm/Support/TimeValue.h"
#include <cstdio>
using namespace llvm;
+#define DEBUG_TYPE "WinCOFFObjectWriter"
+
namespace {
-typedef llvm::SmallString<COFF::NameSize> name;
+typedef SmallString<COFF::NameSize> name;
enum AuxiliaryType {
ATFunctionDefinition,
COFF::Auxiliary Aux;
};
+class COFFSymbol;
+class COFFSection;
+
class COFFSymbol {
public:
COFF::symbol Data;
- typedef
llvm::SmallVector<AuxSymbol, 1> AuxiliarySymbols;
+ typedef SmallVector<AuxSymbol, 1> AuxiliarySymbols;
name Name;
- size_t Index;
+ int Index;
AuxiliarySymbols Aux;
COFFSymbol *Other;
+ COFFSection *Section;
+ int Relocations;
MCSymbolData const *MCData;
- COFFSymbol(llvm::StringRef name, size_t index);
+ COFFSymbol(StringRef name);
size_t size() const;
void set_name_offset(uint32_t Offset);
+
+ bool should_keep() const;
};
// This class contains staging data for a COFF relocation entry.
COFF::relocation Data;
COFFSymbol *Symb;
- COFFRelocation() : Symb(NULL) {}
+ COFFRelocation() : Symb(nullptr) {}
static size_t size() { return COFF::RelocationSize; }
};
COFF::section Header;
std::string Name;
- size_t Number;
+ int Number;
MCSectionData const *MCData;
- COFFSymbol *Symb;
+ COFFSymbol *Symbol;
relocations Relocations;
- COFFSection(llvm::StringRef name, size_t Index);
+ COFFSection(StringRef name);
static size_t size();
};
// This class holds the COFF string table.
class StringTable {
- typedef llvm::StringMap<size_t> map;
+ typedef StringMap<size_t> map;
map Map;
void update_length();
StringTable();
size_t size() const;
- size_t insert(llvm::StringRef String);
+ size_t insert(StringRef String);
};
class WinCOFFObjectWriter : public MCObjectWriter {
public:
- typedef std::vector<COFFSymbol*> symbols;
- typedef std::vector<COFFSection*> sections;
+ typedef std::vector<std::unique_ptr<COFFSymbol>> symbols;
+ typedef std::vector<std::unique_ptr<COFFSection>> sections;
- typedef StringMap<COFFSymbol *> name_symbol_map;
- typedef StringMap<COFFSection *> name_section_map;
+ typedef DenseMap<MCSymbol const *, COFFSymbol *> symbol_map;
+ typedef DenseMap<MCSection const *, COFFSection *> section_map;
- typedef DenseMap<MCSymbolData const *, COFFSymbol *> symbol_map;
- typedef DenseMap<MCSectionData const *, COFFSection *> section_map;
+ std::unique_ptr<MCWinCOFFObjectTargetWriter> TargetObjectWriter;
// Root level file contents.
COFF::header Header;
section_map SectionMap;
symbol_map SymbolMap;
- WinCOFFObjectWriter(raw_ostream &OS);
+ WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW, raw_ostream &OS);
- COFFSymbol *createSymbol(llvm::StringRef Name);
- COFFSection *createSection(llvm::StringRef Name);
-
- void InitCOFFEntity(COFFSymbol &Symbol);
- void InitCOFFEntity(COFFSection &Section);
+ COFFSymbol *createSymbol(StringRef Name);
+ COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol * Symbol);
+ COFFSection *createSection(StringRef Name);
template <typename object_t, typename list_t>
- object_t *createCOFFEntity(llvm::StringRef Name, list_t &List);
+ object_t *createCOFFEntity(StringRef Name, list_t &List);
void DefineSection(MCSectionData const &SectionData);
- void DefineSymbol(MCSymbolData const &SymbolData, MCAssembler &Assembler);
+ void DefineSymbol(MCSymbolData const &SymbolData, MCAssembler &Assembler,
+ const MCAsmLayout &Layout);
+
+ void MakeSymbolReal(COFFSymbol &S, size_t Index);
+ void MakeSectionReal(COFFSection &S, size_t Number);
- bool ExportSection(COFFSection *S);
bool ExportSymbol(MCSymbolData const &SymbolData, MCAssembler &Asm);
+ bool IsPhysicalSection(COFFSection *S);
+
// Entity writing methods.
void WriteFileHeader(const COFF::header &Header);
- void WriteSymbol(const COFFSymbol *S);
+ void WriteSymbol(const COFFSymbol &S);
void WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols &S);
void WriteSectionHeader(const COFF::section &S);
void WriteRelocation(const COFF::relocation &R);
// MCObjectWriter interface implementation.
- void ExecutePostLayoutBinding(MCAssembler &Asm);
+ void ExecutePostLayoutBinding(MCAssembler &Asm,
+ const MCAsmLayout &Layout) override;
- void RecordRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
- const MCFragment *Fragment,
- const MCFixup &Fixup,
- MCValue Target,
- uint64_t &FixedValue);
+ void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
+ const MCFragment *Fragment, const MCFixup &Fixup,
+ MCValue Target, bool &IsPCRel,
+ uint64_t &FixedValue) override;
- void WriteObject(const MCAssembler &Asm, const MCAsmLayout &Layout);
+ void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
};
}
Ptr[3] = (Value & 0xFF000000) >> 24;
}
-static inline void write_uint16_le(void *Data, uint16_t const &Value) {
- uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
- Ptr[0] = (Value & 0x00FF) >> 0;
- Ptr[1] = (Value & 0xFF00) >> 8;
-}
-
-static inline void write_uint8_le(void *Data, uint8_t const &Value) {
- uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
- Ptr[0] = (Value & 0xFF) >> 0;
-}
-
//------------------------------------------------------------------------------
// Symbol class implementation
-COFFSymbol::COFFSymbol(llvm::StringRef name, size_t index)
- : Name(name.begin(), name.end()), Index(-1)
- , Other(NULL), MCData(NULL) {
+COFFSymbol::COFFSymbol(StringRef name)
+ : Name(name.begin(), name.end())
+ , Other(nullptr)
+ , Section(nullptr)
+ , Relocations(0)
+ , MCData(nullptr) {
memset(&Data, 0, sizeof(Data));
}
write_uint32_le(Data.Name + 4, Offset);
}
+/// logic to decide if the symbol should be reported in the symbol table
+bool COFFSymbol::should_keep() const {
+ // no section means its external, keep it
+ if (!Section)
+ return true;
+
+ // if it has relocations pointing at it, keep it
+ if (Relocations > 0) {
+ assert(Section->Number != -1 && "Sections with relocations must be real!");
+ return true;
+ }
+
+ // if the section its in is being droped, drop it
+ if (Section->Number == -1)
+ return false;
+
+ // if it is the section symbol, keep it
+ if (Section->Symbol == this)
+ return true;
+
+ // if its temporary, drop it
+ if (MCData && MCData->getSymbol().isTemporary())
+ return false;
+
+ // otherwise, keep it
+ return true;
+}
+
//------------------------------------------------------------------------------
// Section class implementation
-COFFSection::COFFSection(llvm::StringRef name, size_t Index)
- : Name(name), Number(Index + 1)
- , MCData(NULL), Symb(NULL) {
+COFFSection::COFFSection(StringRef name)
+ : Name(name)
+ , MCData(nullptr)
+ , Symbol(nullptr) {
memset(&Header, 0, sizeof(Header));
}
// The string table data begins with the length of the entire string table
// including the length header. Allocate space for this header.
Data.resize(4);
+ update_length();
}
size_t StringTable::size() const {
/// Add String to the table iff it is not already there.
/// @returns the index into the string table where the string is now located.
-size_t StringTable::insert(llvm::StringRef String) {
+size_t StringTable::insert(StringRef String) {
map::iterator i = Map.find(String);
if (i != Map.end())
//------------------------------------------------------------------------------
// WinCOFFObjectWriter class implementation
-WinCOFFObjectWriter::WinCOFFObjectWriter(raw_ostream &OS)
- : MCObjectWriter(OS, true) {
+WinCOFFObjectWriter::WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW,
+ raw_ostream &OS)
+ : MCObjectWriter(OS, true)
+ , TargetObjectWriter(MOTW) {
memset(&Header, 0, sizeof(Header));
- // TODO: Move magic constant out to COFF.h
- Header.Machine = 0x14C; // x86
-}
-COFFSymbol *WinCOFFObjectWriter::createSymbol(llvm::StringRef Name) {
- return createCOFFEntity<COFFSymbol>(Name, Symbols);
+ Header.Machine = TargetObjectWriter->getMachine();
}
-COFFSection *WinCOFFObjectWriter::createSection(llvm::StringRef Name) {
- return createCOFFEntity<COFFSection>(Name, Sections);
+COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
+ return createCOFFEntity<COFFSymbol>(Name, Symbols);
}
-/// This function initializes a symbol by entering its name into the string
-/// table if it is too long to fit in the symbol table header.
-void WinCOFFObjectWriter::InitCOFFEntity(COFFSymbol &S) {
- if (S.Name.size() > COFF::NameSize) {
- size_t StringTableEntry = Strings.insert(S.Name.c_str());
-
- S.set_name_offset(StringTableEntry);
- } else
- memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
+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;
}
-/// This function initializes a section by entering its name into the string
-/// table if it is too long to fit in the section table header.
-void WinCOFFObjectWriter::InitCOFFEntity(COFFSection &S) {
- if (S.Name.size() > COFF::NameSize) {
- size_t StringTableEntry = Strings.insert(S.Name.c_str());
-
- // FIXME: Why is this number 999999? This number is never mentioned in the
- // spec. I'm assuming this is due to the printed value needing to fit into
- // the S.Header.Name field. In which case why not 9999999 (7 9's instead of
- // 6)? The spec does not state if this entry should be null terminated in
- // this case, and thus this seems to be the best way to do it. I think I
- // just solved my own FIXME...
- if (StringTableEntry > 999999)
- report_fatal_error("COFF string table is greater than 999999 bytes.");
-
- sprintf(S.Header.Name, "/%d", StringTableEntry);
- } else
- memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
+COFFSection *WinCOFFObjectWriter::createSection(StringRef Name) {
+ return createCOFFEntity<COFFSection>(Name, Sections);
}
/// 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(llvm::StringRef Name,
+object_t *WinCOFFObjectWriter::createCOFFEntity(StringRef Name,
list_t &List) {
- object_t *Object = new object_t(Name, List.size());
-
- InitCOFFEntity(*Object);
+ List.push_back(make_unique<object_t>(Name));
- List.push_back(Object);
-
- return Object;
+ 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(MCSectionData const &SectionData) {
+ assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
+ && "Got non-COFF section in the COFF backend!");
// FIXME: Not sure how to verify this (at least in a debug build).
MCSectionCOFF const &Sec =
static_cast<MCSectionCOFF const &>(SectionData.getSection());
COFFSection *coff_section = createSection(Sec.getSectionName());
COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
- coff_section->Symb = coff_symbol;
+ coff_section->Symbol = coff_symbol;
+ coff_symbol->Section = coff_section;
coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
- coff_symbol->Data.SectionNumber = coff_section->Number;
// 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.Number = coff_section->Number;
coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
coff_section->Header.Characteristics = Sec.getCharacteristics();
// Bind internal COFF section to MC section.
coff_section->MCData = &SectionData;
- SectionMap[&SectionData] = coff_section;
+ SectionMap[&SectionData.getSection()] = coff_section;
}
-/// This function takes a section data object from the assembler
+/// This function takes a symbol data object from the assembler
/// and creates the associated COFF symbol staging object.
void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
- MCAssembler &Assembler) {
- COFFSymbol *coff_symbol = createSymbol(SymbolData.getSymbol().getName());
+ MCAssembler &Assembler,
+ const MCAsmLayout &Layout) {
+ MCSymbol const &Symbol = SymbolData.getSymbol();
+ COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&Symbol);
+ SymbolMap[&Symbol] = coff_symbol;
- coff_symbol->Data.Type = (SymbolData.getFlags() & 0x0000FFFF) >> 0;
- coff_symbol->Data.StorageClass = (SymbolData.getFlags() & 0x00FF0000) >> 16;
+ if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
+ coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
- // If no storage class was specified in the streamer, define it here.
- if (coff_symbol->Data.StorageClass == 0) {
- bool external = SymbolData.isExternal() || (SymbolData.Fragment == NULL);
+ if (Symbol.isVariable()) {
+ const MCSymbolRefExpr *SymRef =
+ dyn_cast<MCSymbolRefExpr>(Symbol.getVariableValue());
+
+ if (!SymRef)
+ report_fatal_error("Weak externals may only alias symbols");
+
+ coff_symbol->Other = GetOrCreateCOFFSymbol(&SymRef->getSymbol());
+ } else {
+ std::string WeakName = std::string(".weak.")
+ + Symbol.getName().str()
+ + ".default";
+ COFFSymbol *WeakDefault = createSymbol(WeakName);
+ WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
+ WeakDefault->Data.StorageClass = COFF::IMAGE_SYM_CLASS_EXTERNAL;
+ WeakDefault->Data.Type = 0;
+ WeakDefault->Data.Value = 0;
+ coff_symbol->Other = WeakDefault;
+ }
- coff_symbol->Data.StorageClass =
- external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
- }
+ // 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 =
+ COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
+
+ coff_symbol->MCData = &SymbolData;
+ } else {
+ const MCSymbolData &ResSymData =
+ Assembler.getSymbolData(Symbol.AliasedSymbol());
+
+ if (Symbol.isVariable()) {
+ int64_t Addr;
+ if (Symbol.getVariableValue()->EvaluateAsAbsolute(Addr, Layout))
+ coff_symbol->Data.Value = Addr;
+ } else if (SymbolData.isExternal() && SymbolData.isCommon()) {
+ coff_symbol->Data.Value = SymbolData.getCommonSize();
+ }
- if (SymbolData.getFlags() & COFF::SF_WeakReference) {
- coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
+ coff_symbol->Data.Type = (ResSymData.getFlags() & 0x0000FFFF) >> 0;
+ coff_symbol->Data.StorageClass = (ResSymData.getFlags() & 0x00FF0000) >> 16;
- const MCExpr *Value = SymbolData.getSymbol().getVariableValue();
+ // If no storage class was specified in the streamer, define it here.
+ if (coff_symbol->Data.StorageClass == 0) {
+ bool external = ResSymData.isExternal() || !ResSymData.Fragment;
- // FIXME: This assert message isn't very good.
- assert(Value->getKind() == MCExpr::SymbolRef &&
- "Value must be a SymbolRef!");
+ coff_symbol->Data.StorageClass =
+ external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
+ }
- const MCSymbolRefExpr *SymbolRef =
- static_cast<const MCSymbolRefExpr *>(Value);
+ if (Symbol.isAbsolute() || Symbol.AliasedSymbol().isVariable())
+ coff_symbol->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
+ else if (ResSymData.Fragment)
+ coff_symbol->Section =
+ SectionMap[&ResSymData.Fragment->getParent()->getSection()];
- const MCSymbolData &OtherSymbolData =
- Assembler.getSymbolData(SymbolRef->getSymbol());
+ coff_symbol->MCData = &ResSymData;
+ }
+}
- // FIXME: This assert message isn't very good.
- assert(SymbolMap.find(&OtherSymbolData) != SymbolMap.end() &&
- "OtherSymbolData must be in the symbol map!");
+// Maximum offsets for different string table entry encodings.
+static const unsigned Max6DecimalOffset = 999999;
+static const unsigned Max7DecimalOffset = 9999999;
+static const uint64_t MaxBase64Offset = 0xFFFFFFFFFULL; // 64^6, including 0
- coff_symbol->Other = SymbolMap[&OtherSymbolData];
+// Encode a string table entry offset in base 64, padded to 6 chars, and
+// prefixed with a double slash: '//AAAAAA', '//AAAAAB', ...
+// Buffer must be at least 8 bytes large. No terminating null appended.
+static void encodeBase64StringEntry(char* Buffer, uint64_t Value) {
+ assert(Value > Max7DecimalOffset && Value <= MaxBase64Offset &&
+ "Illegal section name encoding for value");
- // 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 =
- COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
+ static const char Alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "abcdefghijklmnopqrstuvwxyz"
+ "0123456789+/";
+
+ Buffer[0] = '/';
+ Buffer[1] = '/';
+
+ char* Ptr = Buffer + 7;
+ for (unsigned i = 0; i < 6; ++i) {
+ unsigned Rem = Value % 64;
+ Value /= 64;
+ *(Ptr--) = Alphabet[Rem];
}
+}
+
+/// making a section real involves assigned it a number and putting
+/// name into the string table if needed
+void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
+ if (S.Name.size() > COFF::NameSize) {
+ uint64_t StringTableEntry = Strings.insert(S.Name.c_str());
+
+ if (StringTableEntry <= Max6DecimalOffset) {
+ std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
+ } else if (StringTableEntry <= Max7DecimalOffset) {
+ // With seven digits, we have to skip the terminating null. Because
+ // sprintf always appends it, we use a larger temporary buffer.
+ char buffer[9] = { };
+ std::sprintf(buffer, "/%d", unsigned(StringTableEntry));
+ std::memcpy(S.Header.Name, buffer, 8);
+ } 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
+ std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
- // Bind internal COFF symbol to MC symbol.
- coff_symbol->MCData = &SymbolData;
- SymbolMap[&SymbolData] = coff_symbol;
+ S.Number = Number;
+ S.Symbol->Data.SectionNumber = S.Number;
+ S.Symbol->Aux[0].Aux.SectionDefinition.Number = S.Number;
}
-bool WinCOFFObjectWriter::ExportSection(COFFSection *S) {
- return (S->Header.Characteristics
- & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
+void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
+ if (S.Name.size() > COFF::NameSize) {
+ size_t StringTableEntry = Strings.insert(S.Name.c_str());
+
+ S.set_name_offset(StringTableEntry);
+ } else
+ std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
+ S.Index = Index;
}
bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
// return Asm.isSymbolLinkerVisible (&SymbolData);
- // For now, all symbols are exported, the linker will sort it out for us.
- return true;
+ // For now, all non-variable symbols are exported,
+ // the linker will sort the rest out for us.
+ return SymbolData.isExternal() || !SymbolData.getSymbol().isVariable();
+}
+
+bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
+ return (S->Header.Characteristics
+ & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
}
//------------------------------------------------------------------------------
WriteLE16(Header.Characteristics);
}
-void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol *S) {
- WriteBytes(StringRef(S->Data.Name, COFF::NameSize));
- WriteLE32(S->Data.Value);
- WriteLE16(S->Data.SectionNumber);
- WriteLE16(S->Data.Type);
- Write8(S->Data.StorageClass);
- Write8(S->Data.NumberOfAuxSymbols);
- WriteAuxiliarySymbols(S->Aux);
+void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol &S) {
+ WriteBytes(StringRef(S.Data.Name, COFF::NameSize));
+ WriteLE32(S.Data.Value);
+ WriteLE16(S.Data.SectionNumber);
+ WriteLE16(S.Data.Type);
+ Write8(S.Data.StorageClass);
+ Write8(S.Data.NumberOfAuxSymbols);
+ WriteAuxiliarySymbols(S.Aux);
}
void WinCOFFObjectWriter::WriteAuxiliarySymbols(
////////////////////////////////////////////////////////////////////////////////
// MCObjectWriter interface implementations
-void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm) {
+void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
// "Define" each section & symbol. This creates section & symbol
- // entries in the staging area and gives them their final indexes.
+ // entries in the staging area.
+
+ static_assert(sizeof(((COFF::AuxiliaryFile *)nullptr)->FileName) == COFF::SymbolSize,
+ "size mismatch for COFF::AuxiliaryFile::FileName");
+ for (auto FI = Asm.file_names_begin(), FE = Asm.file_names_end();
+ FI != FE; ++FI) {
+ // round up to calculate the number of auxiliary symbols required
+ unsigned Count = (FI->size() + COFF::SymbolSize - 1) / COFF::SymbolSize;
+
+ COFFSymbol *file = createSymbol(".file");
+ file->Data.StorageClass = COFF::IMAGE_SYM_CLASS_FILE;
+ file->Aux.resize(Count);
+
+ unsigned Offset = 0;
+ unsigned Length = FI->size();
+ for (auto & Aux : file->Aux) {
+ Aux.AuxType = ATFile;
+
+ if (Length > COFF::SymbolSize) {
+ memcpy(Aux.Aux.File.FileName, FI->c_str() + Offset, COFF::SymbolSize);
+ Length = Length - COFF::SymbolSize;
+ } else {
+ memcpy(Aux.Aux.File.FileName, FI->c_str() + Offset, Length);
+ memset(&Aux.Aux.File.FileName[Length], 0, COFF::SymbolSize - Length);
+ Length = 0;
+ }
+
+ Offset = Offset + COFF::SymbolSize;
+ }
+ }
for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++)
DefineSection(*i);
- for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
- e = Asm.symbol_end(); i != e; i++) {
- if (ExportSymbol(*i, Asm))
- DefineSymbol(*i, Asm);
- }
+ for (MCSymbolData &SD : Asm.symbols())
+ if (ExportSymbol(SD, Asm))
+ DefineSymbol(SD, Asm, Layout);
}
void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
const MCFragment *Fragment,
const MCFixup &Fixup,
MCValue Target,
+ bool &IsPCRel,
uint64_t &FixedValue) {
- assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
- assert(Target.getSymB() == NULL &&
- "Relocation must reference only one symbol!");
+ assert(Target.getSymA() && "Relocation must reference a symbol!");
+
+ const MCSymbol &Symbol = Target.getSymA()->getSymbol();
+ const MCSymbol &A = Symbol.AliasedSymbol();
+ if (!Asm.hasSymbolData(A))
+ Asm.getContext().FatalError(
+ Fixup.getLoc(),
+ Twine("symbol '") + A.getName() + "' can not be undefined");
+
+ MCSymbolData &A_SD = Asm.getSymbolData(A);
MCSectionData const *SectionData = Fragment->getParent();
- MCSymbolData const *SymbolData =
- &Asm.getSymbolData(Target.getSymA()->getSymbol());
- assert(SectionMap.find(SectionData) != SectionMap.end() &&
+ // Mark this symbol as requiring an entry in the symbol table.
+ assert(SectionMap.find(&SectionData->getSection()) != SectionMap.end() &&
"Section must already have been defined in ExecutePostLayoutBinding!");
- assert(SymbolMap.find(SymbolData) != SymbolMap.end() &&
+ assert(SymbolMap.find(&A_SD.getSymbol()) != SymbolMap.end() &&
"Symbol must already have been defined in ExecutePostLayoutBinding!");
- COFFSection *coff_section = SectionMap[SectionData];
- COFFSymbol *coff_symbol = SymbolMap[SymbolData];
-
- FixedValue = Target.getConstant();
+ COFFSection *coff_section = SectionMap[&SectionData->getSection()];
+ COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
+ const MCSymbolRefExpr *SymB = Target.getSymB();
+ bool CrossSection = false;
+
+ if (SymB) {
+ const MCSymbol *B = &SymB->getSymbol();
+ MCSymbolData &B_SD = Asm.getSymbolData(*B);
+ if (!B_SD.getFragment())
+ Asm.getContext().FatalError(
+ Fixup.getLoc(),
+ Twine("symbol '") + B->getName() +
+ "' can not be undefined in a subtraction expression");
+
+ if (!A_SD.getFragment())
+ Asm.getContext().FatalError(
+ Fixup.getLoc(),
+ Twine("symbol '") + Symbol.getName() +
+ "' can not be undefined in a subtraction expression");
+
+ CrossSection = &Symbol.getSection() != &B->getSection();
+
+ // Offset of the symbol in the section
+ int64_t a = Layout.getSymbolOffset(&B_SD);
+
+ // Ofeset of the relocation in the section
+ int64_t b = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
+
+ FixedValue = b - a;
+ // 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)
+ return;
+ } else {
+ FixedValue = Target.getConstant();
+ }
COFFRelocation Reloc;
+ Reloc.Data.SymbolTableIndex = 0;
Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
- Reloc.Symb = coff_symbol;
- Reloc.Data.VirtualAddress += Fixup.getOffset();
+ // Turn relocations for temporary symbols into section relocations.
+ if (coff_symbol->MCData->getSymbol().isTemporary() || CrossSection) {
+ Reloc.Symb = coff_symbol->Section->Symbol;
+ FixedValue += Layout.getFragmentOffset(coff_symbol->MCData->Fragment)
+ + coff_symbol->MCData->getOffset();
+ } else
+ Reloc.Symb = coff_symbol;
- switch (Fixup.getKind()) {
- case FirstTargetFixupKind: // reloc_pcrel_4byte
- Reloc.Data.Type = COFF::IMAGE_REL_I386_REL32;
+ ++Reloc.Symb->Relocations;
+
+ Reloc.Data.VirtualAddress += Fixup.getOffset();
+ Reloc.Data.Type = TargetObjectWriter->getRelocType(Target, Fixup,
+ CrossSection);
+
+ // FIXME: Can anyone explain what this does other than adjust for the size
+ // of the offset?
+ if ((Header.Machine == COFF::IMAGE_FILE_MACHINE_AMD64 &&
+ Reloc.Data.Type == COFF::IMAGE_REL_AMD64_REL32) ||
+ (Header.Machine == COFF::IMAGE_FILE_MACHINE_I386 &&
+ Reloc.Data.Type == COFF::IMAGE_REL_I386_REL32))
FixedValue += 4;
- break;
- case FK_Data_4:
- Reloc.Data.Type = COFF::IMAGE_REL_I386_DIR32;
- break;
- default:
- llvm_unreachable("unsupported relocation type");
- }
coff_section->Relocations.push_back(Reloc);
}
-void WinCOFFObjectWriter::WriteObject(const MCAssembler &Asm,
+void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
const MCAsmLayout &Layout) {
// Assign symbol and section indexes and offsets.
+ Header.NumberOfSections = 0;
+
+ DenseMap<COFFSection *, uint16_t> SectionIndices;
+ for (sections::iterator i = Sections.begin(),
+ e = Sections.end(); i != e; i++) {
+ if (Layout.getSectionAddressSize((*i)->MCData) > 0) {
+ size_t Number = ++Header.NumberOfSections;
+ SectionIndices[i->get()] = Number;
+ MakeSectionReal(**i, Number);
+ } else {
+ (*i)->Number = -1;
+ }
+ }
Header.NumberOfSymbols = 0;
for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
- COFFSymbol *coff_symbol = *i;
- MCSymbolData const *SymbolData = coff_symbol->MCData;
-
- coff_symbol->Index = Header.NumberOfSymbols++;
+ COFFSymbol &coff_symbol = **i;
+ MCSymbolData const *SymbolData = coff_symbol.MCData;
// Update section number & offset for symbols that have them.
- if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) {
- COFFSection *coff_section = SectionMap[SymbolData->Fragment->getParent()];
+ if (SymbolData && SymbolData->Fragment) {
+ assert(coff_symbol.Section != nullptr);
- coff_symbol->Data.SectionNumber = coff_section->Number;
- coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment);
+ coff_symbol.Data.SectionNumber = coff_symbol.Section->Number;
+ coff_symbol.Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
+ + SymbolData->Offset;
}
- // Update auxiliary symbol info.
- coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size();
- Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols;
+ if (coff_symbol.should_keep()) {
+ MakeSymbolReal(coff_symbol, Header.NumberOfSymbols++);
+
+ // Update auxiliary symbol info.
+ coff_symbol.Data.NumberOfAuxSymbols = coff_symbol.Aux.size();
+ Header.NumberOfSymbols += coff_symbol.Data.NumberOfAuxSymbols;
+ } else
+ coff_symbol.Index = -1;
}
// Fixup weak external references.
for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
- COFFSymbol *symb = *i;
-
- if (symb->Other != NULL) {
- assert(symb->Aux.size() == 1 &&
+ COFFSymbol &coff_symbol = **i;
+ if (coff_symbol.Other) {
+ assert(coff_symbol.Index != -1);
+ assert(coff_symbol.Aux.size() == 1 &&
"Symbol must contain one aux symbol!");
- assert(symb->Aux[0].AuxType == ATWeakExternal &&
+ assert(coff_symbol.Aux[0].AuxType == ATWeakExternal &&
"Symbol's aux symbol must be a Weak External!");
- symb->Aux[0].Aux.WeakExternal.TagIndex = symb->Other->Index;
+ coff_symbol.Aux[0].Aux.WeakExternal.TagIndex = coff_symbol.Other->Index;
}
}
+ // Fixup associative COMDAT sections.
+ for (sections::iterator i = Sections.begin(),
+ e = Sections.end(); i != e; i++) {
+ if ((*i)->Symbol->Aux[0].Aux.SectionDefinition.Selection !=
+ COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
+ continue;
+
+ const MCSectionCOFF &MCSec = static_cast<const MCSectionCOFF &>(
+ (*i)->MCData->getSection());
+
+ COFFSection *Assoc = SectionMap.lookup(MCSec.getAssocSection());
+ if (!Assoc) {
+ report_fatal_error(Twine("Missing associated COMDAT section ") +
+ MCSec.getAssocSection()->getSectionName() +
+ " for section " + MCSec.getSectionName());
+ }
+
+ // Skip this section if the associated section is unused.
+ if (Assoc->Number == -1)
+ continue;
+
+ (*i)->Symbol->Aux[0].Aux.SectionDefinition.Number = SectionIndices[Assoc];
+ }
+
+
// Assign file offsets to COFF object file structures.
unsigned offset = 0;
offset += COFF::HeaderSize;
- offset += COFF::SectionSize * Asm.size();
-
- Header.NumberOfSections = Sections.size();
+ offset += COFF::SectionSize * Header.NumberOfSections;
for (MCAssembler::const_iterator i = Asm.begin(),
e = Asm.end();
i != e; i++) {
- COFFSection *Sec = SectionMap[i];
+ COFFSection *Sec = SectionMap[&i->getSection()];
- Sec->Header.SizeOfRawData = Layout.getSectionFileSize(i);
+ if (Sec->Number == -1)
+ continue;
- if (ExportSection(Sec)) {
+ Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i);
+
+ if (IsPhysicalSection(Sec)) {
Sec->Header.PointerToRawData = offset;
offset += Sec->Header.SizeOfRawData;
}
if (Sec->Relocations.size() > 0) {
- Sec->Header.NumberOfRelocations = Sec->Relocations.size();
+ bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
+
+ if (RelocationsOverflow) {
+ // Signal overflow by setting NumberOfSections 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 (relocations::iterator cr = Sec->Relocations.begin(),
er = Sec->Relocations.end();
- cr != er; cr++) {
+ cr != er; ++cr) {
+ assert((*cr).Symb->Index != -1);
(*cr).Data.SymbolTableIndex = (*cr).Symb->Index;
}
}
- assert(Sec->Symb->Aux.size() == 1 && "Section's symbol must have one aux!");
- AuxSymbol &Aux = Sec->Symb->Aux[0];
+ 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;
Header.PointerToSymbolTable = offset;
+ // We want a deterministic output. It looks like GNU as also writes 0 in here.
+ Header.TimeDateStamp = 0;
+
// Write it all to disk...
WriteFileHeader(Header);
MCAssembler::const_iterator j, je;
for (i = Sections.begin(), ie = Sections.end(); i != ie; i++)
- WriteSectionHeader((*i)->Header);
+ if ((*i)->Number != -1) {
+ if ((*i)->Relocations.size() >= 0xffff) {
+ (*i)->Header.Characteristics |= COFF::IMAGE_SCN_LNK_NRELOC_OVFL;
+ }
+ WriteSectionHeader((*i)->Header);
+ }
for (i = Sections.begin(), ie = Sections.end(),
j = Asm.begin(), je = Asm.end();
- (i != ie) && (j != je); i++, j++) {
+ (i != ie) && (j != je); ++i, ++j) {
+
+ if ((*i)->Number == -1)
+ continue;
+
if ((*i)->Header.PointerToRawData != 0) {
assert(OS.tell() == (*i)->Header.PointerToRawData &&
"Section::PointerToRawData is insane!");
- Asm.WriteSectionData(j, Layout, this);
+ Asm.writeSectionData(j, Layout);
}
if ((*i)->Relocations.size() > 0) {
assert(OS.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 (relocations::const_iterator k = (*i)->Relocations.begin(),
ke = (*i)->Relocations.end();
k != ke; k++) {
"Header::PointerToSymbolTable is insane!");
for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++)
- WriteSymbol(*i);
+ if ((*i)->Index != -1)
+ WriteSymbol(**i);
OS.write((char const *)&Strings.Data.front(), Strings.Data.size());
}
+MCWinCOFFObjectTargetWriter::MCWinCOFFObjectTargetWriter(unsigned Machine_) :
+ Machine(Machine_) {
+}
+
+// Pin the vtable to this file.
+void MCWinCOFFObjectTargetWriter::anchor() {}
+
//------------------------------------------------------------------------------
// WinCOFFObjectWriter factory function
namespace llvm {
- MCObjectWriter *createWinCOFFObjectWriter(raw_ostream &OS) {
- return new WinCOFFObjectWriter(OS);
+ MCObjectWriter *createWinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW,
+ raw_ostream &OS) {
+ return new WinCOFFObjectWriter(MOTW, OS);
}
}
projects / oota-llvm.git / blobdiff