/// Interpret the STAB entries to fill the DebugMap.
void MachODebugMapParser::handleStabSymbolTableEntry(uint32_t StringIndex,
uint8_t Type,
uint8_t SectionIndex,
uint16_t Flags,
uint64_t Value) {
if (!(Type & MachO::N_STAB))
return;
const char *Name = &MainBinaryStrings.data()[StringIndex];
// An N_OSO entry represents the start of a new object file description.
if (Type == MachO::N_OSO) {
sys::TimeValue Timestamp;
Timestamp.fromEpochTime(Value);
return switchToNewDebugMapObject(Name, Timestamp);
}
// If the last N_OSO object file wasn't found,
// CurrentDebugMapObject will be null. Do not update anything
// until we find the next valid N_OSO entry.
if (!CurrentDebugMapObject)
return;
uint32_t Size = 0;
switch (Type) {
case MachO::N_GSYM:
// This is a global variable. We need to query the main binary
// symbol table to find its address as it might not be in the
// debug map (for common symbols).
Value = getMainBinarySymbolAddress(Name);
break;
case MachO::N_FUN:
// Functions are scopes in STABS. They have an end marker that
// contains the function size.
if (Name[0] == '\0') {
Size = Value;
Value = CurrentFunctionAddress;
Name = CurrentFunctionName;
break;
} else {
CurrentFunctionName = Name;
CurrentFunctionAddress = Value;
return;
}
case MachO::N_STSYM:
break;
default:
return;
}
auto ObjectSymIt = CurrentObjectAddresses.find(Name);
if (ObjectSymIt == CurrentObjectAddresses.end())
return Warning("could not find object file symbol for symbol " +
Twine(Name));
if (!CurrentDebugMapObject->addSymbol(Name, ObjectSymIt->getValue(), Value,
Size))
return Warning(Twine("failed to insert symbol '") + Name +
"' in the debug map.");
}
/// Load the current object file symbols into CurrentObjectAddresses.
void MachODebugMapParser::loadCurrentObjectFileSymbols(
const object::MachOObjectFile &Obj) {
CurrentObjectAddresses.clear();
for (auto Sym : Obj.symbols()) {
StringRef Name;
uint64_t Addr = UnknownAddressOrSize;
SymbolRef::Type Type;
StringRef SecName;
// Undefined symbols won't have an address, but we still want
// them, because they might be referenced in the debug information.
Sym.getAddress(Addr);
object::section_iterator Section = Obj.section_end();
if (!Sym.getSection(Section) && Section != Obj.section_end())
Section->getName(SecName);
if (Sym.getName(Name) || Name.empty() ||
Sym.getType(Type) || Type == SymbolRef::ST_Other)
continue;
CurrentObjectAddresses.insert(std::make_pair(Name, std::make_pair(Addr, SecName)));
uint32_t Flags;
Flags = Sym.getFlags();
uint64_t Value;
// FIXME: We put every symbol in the debug map, because of the
// behavior expected from lookupObjectAddress.
Value = getMainBinarySymbolAddress(Name);
// Symbols with no known address on either side are of absolutely
// no use.
if (Addr != UnknownAddressOrSize || Value != UnknownAddressOrSize)
CurrentDebugMapObject->addSymbol(Name, Addr, Value, 0, SecName, true);
}
}