/// This function takes a section data object from the assembler
/// and creates the associated COFF symbol staging object.
void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
MCAssembler &Assembler) {
COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&SymbolData.getSymbol());
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 (SymbolData.getSymbol().isVariable()) {
coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
const MCExpr *Value = SymbolData.getSymbol().getVariableValue();
// FIXME: This assert message isn't very good.
assert(Value->getKind() == MCExpr::SymbolRef &&
"Value must be a SymbolRef!");
const MCSymbolRefExpr *SymbolRef =
static_cast<const MCSymbolRefExpr *>(Value);
coff_symbol->Other = GetOrCreateCOFFSymbol(&SymbolRef->getSymbol());
} else {
std::string WeakName = std::string(".weak.")
+ SymbolData.getSymbol().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;
}
// 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;
}
// 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->Data.StorageClass =
external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
}
if (SymbolData.Fragment != NULL)
coff_symbol->Section =
SectionMap[&SymbolData.Fragment->getParent()->getSection()];
// Bind internal COFF symbol to MC symbol.
coff_symbol->MCData = &SymbolData;
SymbolMap[&SymbolData.getSymbol()] = coff_symbol;
}
bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
MCAssembler &Asm) {
// This doesn't seem to be right. Strings referred to from the .data section
// need symbols so they can be linked to code in the .text section right?
// return Asm.isSymbolLinkerVisible (&SymbolData);
// For now, all non-variable symbols are exported,
// the linker will sort the rest out for us.
return SymbolData.isExternal() || !SymbolData.getSymbol().isVariable();
}
static uint64_t getSymbolValue(const MCSymbolData &Data,
const MCAsmLayout &Layout) {
if (Data.isCommon() && Data.isExternal())
return Data.getCommonSize();
uint64_t Res;
if (!Layout.getSymbolOffset(&Data, Res))
return 0;
return Res;
}
/// 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,
const MCAsmLayout &Layout) {
MCSymbol const &Symbol = SymbolData.getSymbol();
COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&Symbol);
SymbolMap[&Symbol] = coff_symbol;
if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
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;
}
// 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();
}
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;
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)
coff_symbol->Section =
SectionMap[&ResSymData.Fragment->getParent()->getSection()];
coff_symbol->MCData = &ResSymData;
}
}