#include "DWARFDebugFrame.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+#include <vector>
using namespace llvm;
using namespace dwarf;
}
FrameKind getKind() const { return Kind; }
+ 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
+ /// returns. Otherwise, an error occurred.
+ 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;
+ /// \brief Dump the entry's instructions to the given output stream.
+ virtual void dumpInstructions(raw_ostream &OS) const;
+
protected:
const FrameKind Kind;
/// \brief Entry length as specified in DWARF.
uint64_t Length;
+
+ /// An entry may contain CFI instructions. An instruction consists of an
+ /// opcode and an optional sequence of operands.
+ typedef std::vector<uint64_t> Operands;
+ struct Instruction {
+ Instruction(uint8_t Opcode)
+ : Opcode(Opcode)
+ {}
+
+ uint8_t Opcode;
+ Operands Ops;
+ };
+
+ std::vector<Instruction> Instructions;
+
+ /// Convenience methods to add a new instruction with the given opcode and
+ /// operands to the Instructions vector.
+ void addInstruction(uint8_t Opcode) {
+ Instructions.push_back(Instruction(Opcode));
+ }
+
+ void addInstruction(uint8_t Opcode, uint64_t Operand1) {
+ Instructions.push_back(Instruction(Opcode));
+ Instructions.back().Ops.push_back(Operand1);
+ }
+
+ void addInstruction(uint8_t Opcode, uint64_t Operand1, uint64_t Operand2) {
+ Instructions.push_back(Instruction(Opcode));
+ Instructions.back().Ops.push_back(Operand1);
+ Instructions.back().Ops.push_back(Operand2);
+ }
};
+// See DWARF standard v3, section 7.23
+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);
+ // Some instructions have a primary opcode encoded in the top bits.
+ uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK;
+
+ if (Primary) {
+ // If it's a primary opcode, the first operand is encoded in the bottom
+ // bits of the opcode itself.
+ uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK;
+ switch (Primary) {
+ default: llvm_unreachable("Impossible primary CFI opcode");
+ case DW_CFA_advance_loc:
+ case DW_CFA_restore:
+ addInstruction(Primary, Op1);
+ break;
+ case DW_CFA_offset:
+ addInstruction(Primary, Op1, Data.getULEB128(Offset));
+ break;
+ }
+ } else {
+ // Extended opcode - its value is Opcode itself.
+ switch (Opcode) {
+ default: llvm_unreachable("Invalid extended CFI opcode");
+ case DW_CFA_nop:
+ case DW_CFA_remember_state:
+ case DW_CFA_restore_state:
+ // No operands
+ addInstruction(Opcode);
+ break;
+ case DW_CFA_set_loc:
+ // Operands: Address
+ addInstruction(Opcode, Data.getAddress(Offset));
+ break;
+ case DW_CFA_advance_loc1:
+ // Operands: 1-byte delta
+ addInstruction(Opcode, Data.getU8(Offset));
+ break;
+ case DW_CFA_advance_loc2:
+ // Operands: 2-byte delta
+ addInstruction(Opcode, Data.getU16(Offset));
+ break;
+ case DW_CFA_advance_loc4:
+ // Operands: 4-byte delta
+ addInstruction(Opcode, Data.getU32(Offset));
+ break;
+ case DW_CFA_restore_extended:
+ case DW_CFA_undefined:
+ case DW_CFA_same_value:
+ case DW_CFA_def_cfa_register:
+ case DW_CFA_def_cfa_offset:
+ // Operands: ULEB128
+ addInstruction(Opcode, Data.getULEB128(Offset));
+ break;
+ case DW_CFA_def_cfa_offset_sf:
+ // Operands: SLEB128
+ 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));
+ 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));
+ break;
+ case DW_CFA_def_cfa_expression:
+ case DW_CFA_expression:
+ case DW_CFA_val_expression:
+ // TODO: implement this
+ report_fatal_error("Values with expressions not implemented yet!");
+ }
+ }
+ }
+}
+
+
+void FrameEntry::dumpInstructions(raw_ostream &OS) const {
+ // TODO: at the moment only instruction names are dumped. Expand this to
+ // dump operands as well.
+ for (std::vector<Instruction>::const_iterator I = Instructions.begin(),
+ E = Instructions.end();
+ I != E; ++I) {
+ uint8_t Opcode = I->Opcode;
+ if (Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK)
+ Opcode &= DWARF_CFI_PRIMARY_OPCODE_MASK;
+ OS << " " << CallFrameString(Opcode) << ":\n";
+ }
+}
+
+
+namespace {
/// \brief DWARF Common Information Entry (CIE)
class CIE : public FrameEntry {
public:
<< "\n";
OS << format(" Version: %d\n", Version);
OS << " Augmentation: \"" << Augmentation << "\"\n";
- OS << format(" Code alignment factor: %u\n", (uint32_t)CodeAlignmentFactor);
- OS << format(" Data alignment factor: %d\n", (int32_t)DataAlignmentFactor);
- OS << format(" Return address column: %d\n", (int32_t)ReturnAddressRegister);
+ OS << format(" Code alignment factor: %u\n",
+ (uint32_t)CodeAlignmentFactor);
+ OS << format(" Data alignment factor: %d\n",
+ (int32_t)DataAlignmentFactor);
+ OS << format(" Return address column: %d\n",
+ (int32_t)ReturnAddressRegister);
OS << "\n";
}
(int32_t)LinkedCIEOffset,
(uint32_t)InitialLocation,
(uint32_t)InitialLocation + (uint32_t)AddressRange);
- OS << "\n";
if (LinkedCIE) {
OS << format("%p\n", LinkedCIE);
}
uint64_t AddressRange;
CIE *LinkedCIE;
};
+} // end anonymous namespace
DWARFDebugFrame::DWARFDebugFrame() {
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);
}
- Offset = EndStructureOffset;
+ assert(Entry && "Expected Entry to be populated with CIE or FDE");
+ Entry->parseInstructions(&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",
+ Entry->getOffset());
+ report_fatal_error(Str);
+ }
}
}
OS << "\n";
for (EntryVector::const_iterator I = Entries.begin(), E = Entries.end();
I != E; ++I) {
- (*I)->dumpHeader(OS);
+ FrameEntry *Entry = *I;
+ Entry->dumpHeader(OS);
+ Entry->dumpInstructions(OS);
+ OS << "\n";
}
}
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