#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
symbol_map SymbolMap;
WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW, raw_ostream &OS);
- ~WinCOFFObjectWriter();
+ virtual ~WinCOFFObjectWriter();
COFFSymbol *createSymbol(StringRef Name);
COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol * Symbol);
object_t *createCOFFEntity(StringRef Name, list_t &List);
void DefineSection(MCSectionData const &SectionData);
- void DefineSymbol(MCSymbol const &Symbol,
- 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 const *S);
bool ExportSymbol(MCSymbolData const &SymbolData, MCAssembler &Asm);
bool IsPhysicalSection(COFFSection *S);
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
/// 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!");
+ && "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());
/// This function takes a section data object from the assembler
/// and creates the associated COFF symbol staging object.
-void WinCOFFObjectWriter::DefineSymbol(MCSymbol const &Symbol,
- MCSymbolData const &SymbolData,
- MCAssembler &Assembler) {
+void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
+ MCAssembler &Assembler,
+ const MCAsmLayout &Layout) {
+ MCSymbol const &Symbol = SymbolData.getSymbol();
COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&Symbol);
-
- coff_symbol->Data.Type = (SymbolData.getFlags() & 0x0000FFFF) >> 0;
- coff_symbol->Data.StorageClass = (SymbolData.getFlags() & 0x00FF0000) >> 16;
+ SymbolMap[&Symbol] = coff_symbol;
if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
if (Symbol.isVariable()) {
- coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
- const MCExpr *Value = Symbol.getVariableValue();
+ const MCSymbolRefExpr *SymRef =
+ dyn_cast<MCSymbolRefExpr>(Symbol.getVariableValue());
- // FIXME: This assert message isn't very good.
- assert(Value->getKind() == MCExpr::SymbolRef &&
- "Value must be a SymbolRef!");
+ if (!SymRef)
+ report_fatal_error("Weak externals may only alias symbols");
- const MCSymbolRefExpr *SymbolRef =
- static_cast<const MCSymbolRefExpr *>(Value);
- coff_symbol->Other = GetOrCreateCOFFSymbol(&Symbol);
+ coff_symbol->Other = GetOrCreateCOFFSymbol(&SymRef->getSymbol());
} else {
std::string WeakName = std::string(".weak.")
+ Symbol.getName().str()
coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
- }
- // 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);
+ 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;
+ }
- coff_symbol->Data.StorageClass =
- external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
+ coff_symbol->Data.Type = (ResSymData.getFlags() & 0x0000FFFF) >> 0;
+ coff_symbol->Data.StorageClass = (ResSymData.getFlags() & 0x00FF0000) >> 16;
+
+ // If no storage class was specified in the streamer, define it here.
+ if (coff_symbol->Data.StorageClass == 0) {
+ bool external = ResSymData.isExternal() || (ResSymData.Fragment == NULL);
+
+ coff_symbol->Data.StorageClass =
+ external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
+ }
+
+ if (Symbol.isAbsolute() || Symbol.AliasedSymbol().isVariable())
+ coff_symbol->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
+ else if (ResSymData.Fragment != NULL)
+ coff_symbol->Section =
+ SectionMap[&ResSymData.Fragment->getParent()->getSection()];
+
+ coff_symbol->MCData = &ResSymData;
}
+}
- if (SymbolData.Fragment != NULL)
- coff_symbol->Section =
- SectionMap[&SymbolData.Fragment->getParent()->getSection()];
+// 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
- // Bind internal COFF symbol to MC symbol.
- coff_symbol->MCData = &SymbolData;
- SymbolMap[&Symbol] = coff_symbol;
+// 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");
+
+ 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) {
- 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.");
-
- std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
+ 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());
S.Index = Index;
}
-bool WinCOFFObjectWriter::ExportSection(COFFSection const *S) {
- return !S->MCData->getFragmentList().empty();
-}
-
bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
MCAssembler &Asm) {
// This doesn't seem to be right. Strings referred to from the .data section
DefineSection(*i);
for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
- e = Asm.symbol_end(); i != e; i++) {
+ e = Asm.symbol_end();
+ i != e; i++) {
if (ExportSymbol(*i, Asm)) {
- const MCSymbol &Alias = i->getSymbol();
- const MCSymbol &Symbol = Alias.AliasedSymbol();
- DefineSymbol(Alias, Asm.getSymbolData(Symbol), Asm);
+ DefineSymbol(*i, Asm, Layout);
}
}
}
uint64_t &FixedValue) {
assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
- const MCSymbol *A = &Target.getSymA()->getSymbol();
- MCSymbolData &A_SD = Asm.getSymbolData(*A);
+ 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();
COFFSection *coff_section = SectionMap[&SectionData->getSection()];
COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
- const MCSymbolRefExpr *SymA = Target.getSymA();
const MCSymbolRefExpr *SymB = Target.getSymB();
- const bool CrossSection = SymB &&
- &SymA->getSymbol().getSection() != &SymB->getSymbol().getSection();
+ bool CrossSection = false;
- if (Target.getSymB()) {
- const MCSymbol *B = &Target.getSymB()->getSymbol();
+ 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);
++Reloc.Symb->Relocations;
Reloc.Data.VirtualAddress += Fixup.getOffset();
-
- unsigned FixupKind = Fixup.getKind();
-
- if (CrossSection)
- FixupKind = FK_PCRel_4;
-
- Reloc.Data.Type = TargetObjectWriter->getRelocType(FixupKind);
+ Reloc.Data.Type = TargetObjectWriter->getRelocType(Target, Fixup,
+ CrossSection);
// FIXME: Can anyone explain what this does other than adjust for the size
// of the offset?
// 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) {
- MakeSectionReal(**i, ++Header.NumberOfSections);
+ size_t Number = ++Header.NumberOfSections;
+ SectionIndices[*i] = Number;
+ MakeSectionReal(**i, Number);
} else {
(*i)->Number = -1;
}
}
}
+ // 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;
Header.PointerToSymbolTable = offset;
- Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
+ // 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);
Machine(Machine_) {
}
+// Pin the vtable to this file.
+void MCWinCOFFObjectTargetWriter::anchor() {}
+
//------------------------------------------------------------------------------
// WinCOFFObjectWriter factory function