/// EmitDwarfRegOp - Emit dwarf register operation.
void AsmPrinter::EmitDwarfRegOp(ByteStreamer &Streamer,
const MachineLocation &MLoc) const {
DebugLocDwarfExpression Expr(*MF->getSubtarget().getRegisterInfo(),
getDwarfDebug()->getDwarfVersion(), Streamer);
const MCRegisterInfo *MRI = MMI->getContext().getRegisterInfo();
int Reg = MRI->getDwarfRegNum(MLoc.getReg(), false);
if (Reg < 0) {
// We assume that pointers are always in an addressable register.
if (MLoc.isIndirect())
// FIXME: We have no reasonable way of handling errors in here. The
// caller might be in the middle of a dwarf expression. We should
// probably assert that Reg >= 0 once debug info generation is more
// mature.
return Expr.EmitOp(dwarf::DW_OP_nop,
"nop (could not find a dwarf register number)");
// Attempt to find a valid super- or sub-register.
if (!Expr.AddMachineRegPiece(MLoc.getReg()))
Expr.EmitOp(dwarf::DW_OP_nop,
"nop (could not find a dwarf register number)");
return;
}
if (MLoc.isIndirect())
Expr.AddRegIndirect(Reg, MLoc.getOffset());
else
Expr.AddReg(Reg);
}
/// EmitDwarfRegOp - Emit dwarf register operation.
void AsmPrinter::EmitDwarfRegOp(ByteStreamer &Streamer,
const MachineLocation &MLoc,
bool Indirect) const {
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
if (Reg < 0) {
// We assume that pointers are always in an addressable register.
if (Indirect || MLoc.isIndirect()) {
// FIXME: We have no reasonable way of handling errors in here. The
// caller might be in the middle of a dwarf expression. We should
// probably assert that Reg >= 0 once debug info generation is more
// mature.
Streamer.EmitInt8(dwarf::DW_OP_nop,
"nop (invalid dwarf register number for indirect loc)");
return;
}
// Attempt to find a valid super- or sub-register.
if (!Indirect && !MLoc.isIndirect())
return EmitDwarfRegOpPiece(Streamer, *this, MLoc);
}
if (MLoc.isIndirect())
emitDwarfRegOpIndirect(Streamer, Reg, MLoc.getOffset(), Indirect);
else if (Indirect)
emitDwarfRegOpIndirect(Streamer, Reg, 0, false);
else
emitDwarfRegOp(Streamer, Reg);
}
/// addComplexAddress - Start with the address based on the location provided,
/// and generate the DWARF information necessary to find the actual variable
/// given the extra address information encoded in the DIVariable, starting from
/// the starting location. Add the DWARF information to the die.
///
void CompileUnit::addComplexAddress(DbgVariable *&DV, DIE *Die,
unsigned Attribute,
const MachineLocation &Location) {
DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
unsigned N = DV->getNumAddrElements();
unsigned i = 0;
if (Location.isReg()) {
if (N >= 2 && DV->getAddrElement(0) == DIBuilder::OpPlus) {
// If first address element is OpPlus then emit
// DW_OP_breg + Offset instead of DW_OP_reg + Offset.
addRegisterOffset(Block, Location.getReg(), DV->getAddrElement(1));
i = 2;
} else
addRegisterOp(Block, Location.getReg());
}
else
addRegisterOffset(Block, Location.getReg(), Location.getOffset());
for (;i < N; ++i) {
uint64_t Element = DV->getAddrElement(i);
if (Element == DIBuilder::OpPlus) {
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
addUInt(Block, 0, dwarf::DW_FORM_udata, DV->getAddrElement(++i));
} else if (Element == DIBuilder::OpDeref) {
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
} else llvm_unreachable("unknown DIBuilder Opcode");
}
// Now attach the location information to the DIE.
addBlock(Die, Attribute, 0, Block);
}
/// addAddress - Add an address attribute to a die based on the location
/// provided.
void CompileUnit::addAddress(DIE *Die, unsigned Attribute,
const MachineLocation &Location) {
DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
if (Location.isReg())
addRegisterOp(Block, Location.getReg());
else
addRegisterOffset(Block, Location.getReg(), Location.getOffset());
// Now attach the location information to the DIE.
addBlock(Die, Attribute, 0, Block);
}
/// addBlockByrefAddress - Start with the address based on the location
/// provided, and generate the DWARF information necessary to find the
/// actual Block variable (navigating the Block struct) based on the
/// starting location. Add the DWARF information to the die. For
/// more information, read large comment just above here.
///
void CompileUnit::addBlockByrefAddress(DbgVariable *&DV, DIE *Die,
unsigned Attribute,
const MachineLocation &Location) {
DIType Ty = DV->getType();
DIType TmpTy = Ty;
unsigned Tag = Ty.getTag();
bool isPointer = false;
StringRef varName = DV->getName();
if (Tag == dwarf::DW_TAG_pointer_type) {
DIDerivedType DTy = DIDerivedType(Ty);
TmpTy = DTy.getTypeDerivedFrom();
isPointer = true;
}
DICompositeType blockStruct = DICompositeType(TmpTy);
// Find the __forwarding field and the variable field in the __Block_byref
// struct.
DIArray Fields = blockStruct.getTypeArray();
DIDescriptor varField = DIDescriptor();
DIDescriptor forwardingField = DIDescriptor();
for (unsigned i = 0, N = Fields.getNumElements(); i < N; ++i) {
DIDescriptor Element = Fields.getElement(i);
DIDerivedType DT = DIDerivedType(Element);
StringRef fieldName = DT.getName();
if (fieldName == "__forwarding")
forwardingField = Element;
else if (fieldName == varName)
varField = Element;
}
// Get the offsets for the forwarding field and the variable field.
unsigned forwardingFieldOffset =
DIDerivedType(forwardingField).getOffsetInBits() >> 3;
unsigned varFieldOffset =
DIDerivedType(varField).getOffsetInBits() >> 3;
// Decode the original location, and use that as the start of the byref
// variable's location.
const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
unsigned Reg = RI->getDwarfRegNum(Location.getReg(), false);
DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
if (Location.isReg()) {
if (Reg < 32)
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_reg0 + Reg);
else {
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_regx);
addUInt(Block, 0, dwarf::DW_FORM_udata, Reg);
}
} else {
if (Reg < 32)
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_breg0 + Reg);
else {
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_bregx);
addUInt(Block, 0, dwarf::DW_FORM_udata, Reg);
}
addUInt(Block, 0, dwarf::DW_FORM_sdata, Location.getOffset());
}
// If we started with a pointer to the __Block_byref... struct, then
// the first thing we need to do is dereference the pointer (DW_OP_deref).
if (isPointer)
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
// Next add the offset for the '__forwarding' field:
// DW_OP_plus_uconst ForwardingFieldOffset. Note there's no point in
// adding the offset if it's 0.
if (forwardingFieldOffset > 0) {
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
addUInt(Block, 0, dwarf::DW_FORM_udata, forwardingFieldOffset);
}
// Now dereference the __forwarding field to get to the real __Block_byref
// struct: DW_OP_deref.
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
// Now that we've got the real __Block_byref... struct, add the offset
// for the variable's field to get to the location of the actual variable:
// DW_OP_plus_uconst varFieldOffset. Again, don't add if it's 0.
if (varFieldOffset > 0) {
addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
addUInt(Block, 0, dwarf::DW_FORM_udata, varFieldOffset);
}
// Now attach the location information to the DIE.
addBlock(Die, Attribute, 0, Block);
}