Cleanup: Calls to getDwarfRegNum() may actually fail, if there is

no DWARF register number mapping, or if the register was a virtual
register that was never materialized. Previously, we would just emit a
bogus location, after this patch we don't emit a location at all by
doing an early exit.

After my bugfix in r223401 today, this doesn't actually happen on any
target that I tested this with, but it's still preferable to make the
possibility of a failure explicit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223428 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Adrian Prantl 2014-12-05 01:02:46 +00:00
parent af25a5d9b7
commit 74fb019dd0
3 changed files with 44 additions and 27 deletions

View File

@ -746,14 +746,17 @@ void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
bool Indirect) {
DIELoc *Loc = new (DIEValueAllocator) DIELoc();
bool validReg;
if (Location.isReg() && !Indirect)
addRegisterOpPiece(*Loc, Location.getReg());
else {
addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
if (Indirect && !Location.isReg()) {
addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
}
}
validReg = addRegisterOpPiece(*Loc, Location.getReg());
else
validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
if (!validReg)
return;
if (!Location.isReg() && Indirect)
addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
// Now attach the location information to the DIE.
addBlock(Die, Attribute, Loc);
@ -769,25 +772,29 @@ void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
DIELoc *Loc = new (DIEValueAllocator) DIELoc();
unsigned N = DV.getNumAddrElements();
unsigned i = 0;
bool validReg;
if (Location.isReg()) {
if (N >= 2 && DV.getAddrElement(0) == dwarf::DW_OP_plus) {
assert(!DV.getVariable().isIndirect() &&
"double indirection not handled");
// If first address element is OpPlus then emit
// DW_OP_breg + Offset instead of DW_OP_reg + Offset.
addRegisterOffset(*Loc, Location.getReg(), DV.getAddrElement(1));
validReg = addRegisterOffset(*Loc, Location.getReg(), DV.getAddrElement(1));
i = 2;
} else if (N >= 2 && DV.getAddrElement(0) == dwarf::DW_OP_deref) {
assert(!DV.getVariable().isIndirect() &&
"double indirection not handled");
addRegisterOpPiece(*Loc, Location.getReg(),
DV.getExpression().getPieceSize(),
DV.getExpression().getPieceOffset());
validReg = addRegisterOpPiece(*Loc, Location.getReg(),
DV.getExpression().getPieceSize(),
DV.getExpression().getPieceOffset());
i = 3;
} else
addRegisterOpPiece(*Loc, Location.getReg());
validReg = addRegisterOpPiece(*Loc, Location.getReg());
} else
addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
if (!validReg)
return;
for (; i < N; ++i) {
uint64_t Element = DV.getAddrElement(i);

View File

@ -401,7 +401,7 @@ void DwarfUnit::addSourceLine(DIE &Die, DINameSpace NS) {
/// addRegisterOp - Add register operand.
// FIXME: Ideally, this would share the implementation with
// AsmPrinter::EmitDwarfRegOpPiece.
void DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
bool DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
unsigned SizeInBits, unsigned OffsetInBits) {
const TargetRegisterInfo *RI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
int DWReg = RI->getDwarfRegNum(Reg, false);
@ -416,11 +416,8 @@ void DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
Idx = RI->getSubRegIndex(*SR, Reg);
}
if (DWReg < 0) {
DEBUG(dbgs() << "Invalid Dwarf register number.\n");
addUInt(TheDie, dwarf::DW_FORM_data1, dwarf::DW_OP_nop);
return;
}
if (DWReg < 0)
return false;
// Emit register.
if (DWReg < 32)
@ -460,13 +457,17 @@ void DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
addUInt(TheDie, dwarf::DW_FORM_data1, PieceSizeInBits/SizeOfByte);
}
}
return true;
}
/// addRegisterOffset - Add register offset.
void DwarfUnit::addRegisterOffset(DIELoc &TheDie, unsigned Reg,
bool DwarfUnit::addRegisterOffset(DIELoc &TheDie, unsigned Reg,
int64_t Offset) {
const TargetRegisterInfo *RI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
unsigned DWReg = RI->getDwarfRegNum(Reg, false);
int DWReg = RI->getDwarfRegNum(Reg, false);
if (DWReg < 0)
return false;
const TargetRegisterInfo *TRI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
if (Reg == TRI->getFrameRegister(*Asm->MF))
// If variable offset is based in frame register then use fbreg.
@ -478,6 +479,7 @@ void DwarfUnit::addRegisterOffset(DIELoc &TheDie, unsigned Reg,
addUInt(TheDie, dwarf::DW_FORM_udata, DWReg);
}
addSInt(TheDie, dwarf::DW_FORM_sdata, Offset);
return true;
}
/* Byref variables, in Blocks, are declared by the programmer as "SomeType
@ -581,10 +583,14 @@ void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
// variable's location.
DIELoc *Loc = new (DIEValueAllocator) DIELoc();
bool validReg;
if (Location.isReg())
addRegisterOpPiece(*Loc, Location.getReg());
validReg = addRegisterOpPiece(*Loc, Location.getReg());
else
addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
if (!validReg)
return;
// 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).

View File

@ -253,12 +253,16 @@ public:
/// addTemplateParams - Add template parameters in buffer.
void addTemplateParams(DIE &Buffer, DIArray TParams);
/// addRegisterOp - Add register operand.
void addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
/// \brief Add register operand.
/// \returns false if the register does not exist, e.g., because it was never
/// materialized.
bool addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
unsigned SizeInBits = 0, unsigned OffsetInBits = 0);
/// addRegisterOffset - Add register offset.
void addRegisterOffset(DIELoc &TheDie, unsigned Reg, int64_t Offset);
/// \brief Add register offset.
/// \returns false if the register does not exist, e.g., because it was never
/// materialized.
bool addRegisterOffset(DIELoc &TheDie, unsigned Reg, int64_t Offset);
// FIXME: Should be reformulated in terms of addComplexAddress.
/// addBlockByrefAddress - Start with the address based on the location