Code cleanup: pass Offset by pointer to parseInstruction to more explicitly

convey that it's a INOUT argument.
Also, if parsing of entry instructions fails, don't push the entry.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175847 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Bendersky 2013-02-22 00:50:48 +00:00
parent bd2acfab4a
commit 46e0d1d58c

View File

@ -36,11 +36,10 @@ public:
virtual uint64_t getOffset() const { return Offset; }
/// \brief Parse and store a sequence of CFI instructions from our data
/// stream, starting at Offset and ending at EndOffset. If everything
/// goes well, Offset should be equal to EndOffset when this method
/// stream, starting at *Offset and ending at EndOffset. If everything
/// goes well, *Offset should be equal to EndOffset when this method
/// returns. Otherwise, an error occurred.
/// TODO: Improve error reporting...
virtual void parseInstructions(uint32_t &Offset, uint32_t EndOffset);
virtual void parseInstructions(uint32_t *Offset, uint32_t EndOffset);
/// \brief Dump the entry header to the given output stream.
virtual void dumpHeader(raw_ostream &OS) const = 0;
@ -99,9 +98,9 @@ const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0;
const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f;
void FrameEntry::parseInstructions(uint32_t &Offset, uint32_t EndOffset) {
while (Offset < EndOffset) {
uint8_t Opcode = Data.getU8(&Offset);
void FrameEntry::parseInstructions(uint32_t *Offset, uint32_t EndOffset) {
while (*Offset < EndOffset) {
uint8_t Opcode = Data.getU8(Offset);
// Some instructions have a primary opcode encoded in the top bits.
uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK;
@ -116,7 +115,7 @@ void FrameEntry::parseInstructions(uint32_t &Offset, uint32_t EndOffset) {
addInstruction(Primary, Op1);
break;
case DW_CFA_offset:
addInstruction(Primary, Op1, Data.getULEB128(&Offset));
addInstruction(Primary, Op1, Data.getULEB128(Offset));
break;
}
} else {
@ -131,19 +130,19 @@ void FrameEntry::parseInstructions(uint32_t &Offset, uint32_t EndOffset) {
break;
case DW_CFA_set_loc:
// Operands: Address
addInstruction(Opcode, Data.getAddress(&Offset));
addInstruction(Opcode, Data.getAddress(Offset));
break;
case DW_CFA_advance_loc1:
// Operands: 1-byte delta
addInstruction(Opcode, Data.getU8(&Offset));
addInstruction(Opcode, Data.getU8(Offset));
break;
case DW_CFA_advance_loc2:
// Operands: 2-byte delta
addInstruction(Opcode, Data.getU16(&Offset));
addInstruction(Opcode, Data.getU16(Offset));
break;
case DW_CFA_advance_loc4:
// Operands: 4-byte delta
addInstruction(Opcode, Data.getU32(&Offset));
addInstruction(Opcode, Data.getU32(Offset));
break;
case DW_CFA_restore_extended:
case DW_CFA_undefined:
@ -151,26 +150,26 @@ void FrameEntry::parseInstructions(uint32_t &Offset, uint32_t EndOffset) {
case DW_CFA_def_cfa_register:
case DW_CFA_def_cfa_offset:
// Operands: ULEB128
addInstruction(Opcode, Data.getULEB128(&Offset));
addInstruction(Opcode, Data.getULEB128(Offset));
break;
case DW_CFA_def_cfa_offset_sf:
// Operands: SLEB128
addInstruction(Opcode, Data.getSLEB128(&Offset));
addInstruction(Opcode, Data.getSLEB128(Offset));
break;
case DW_CFA_offset_extended:
case DW_CFA_register:
case DW_CFA_def_cfa:
case DW_CFA_val_offset:
// Operands: ULEB128, ULEB128
addInstruction(Opcode, Data.getULEB128(&Offset),
Data.getULEB128(&Offset));
addInstruction(Opcode, Data.getULEB128(Offset),
Data.getULEB128(Offset));
break;
case DW_CFA_offset_extended_sf:
case DW_CFA_def_cfa_sf:
case DW_CFA_val_offset_sf:
// Operands: ULEB128, SLEB128
addInstruction(Opcode, Data.getULEB128(&Offset),
Data.getSLEB128(&Offset));
addInstruction(Opcode, Data.getULEB128(Offset),
Data.getSLEB128(Offset));
break;
case DW_CFA_def_cfa_expression:
case DW_CFA_expression:
@ -337,37 +336,42 @@ void DWARFDebugFrame::parse(DataExtractor Data) {
Id = Data.getUnsigned(&Offset, IsDWARF64 ? 8 : 4);
bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID);
FrameEntry *Entry = 0;
if (IsCIE) {
// Note: this is specifically DWARFv3 CIE header structure. It was
// changed in DWARFv4.
// changed in DWARFv4. We currently don't support reading DWARFv4
// here because LLVM itself does not emit it (and LLDB doesn't
// support it either).
uint8_t Version = Data.getU8(&Offset);
const char *Augmentation = Data.getCStr(&Offset);
uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset);
int64_t DataAlignmentFactor = Data.getSLEB128(&Offset);
uint64_t ReturnAddressRegister = Data.getULEB128(&Offset);
CIE *NewCIE = new CIE(Data, StartOffset, Length, Version,
StringRef(Augmentation), CodeAlignmentFactor,
DataAlignmentFactor, ReturnAddressRegister);
Entries.push_back(NewCIE);
Entry = new CIE(Data, StartOffset, Length, Version,
StringRef(Augmentation), CodeAlignmentFactor,
DataAlignmentFactor, ReturnAddressRegister);
} else {
// FDE
uint64_t CIEPointer = Id;
uint64_t InitialLocation = Data.getAddress(&Offset);
uint64_t AddressRange = Data.getAddress(&Offset);
FDE *NewFDE = new FDE(Data, StartOffset, Length, CIEPointer,
InitialLocation, AddressRange);
Entries.push_back(NewFDE);
Entry = new FDE(Data, StartOffset, Length, CIEPointer,
InitialLocation, AddressRange);
}
Entries.back()->parseInstructions(Offset, EndStructureOffset);
assert(Entry && "Expected Entry to be populated with CIE or FDE");
Entry->parseInstructions(&Offset, EndStructureOffset);
if (Offset != EndStructureOffset) {
if (Offset == EndStructureOffset) {
// Entry instrucitons parsed successfully.
Entries.push_back(Entry);
} else {
std::string Str;
raw_string_ostream OS(Str);
OS << format("Parsing entry instructions at %lx failed",
Entries.back()->getOffset());
Entry->getOffset());
report_fatal_error(Str);
}
}