//
//===----------------------------------------------------------------------===//
-#include "DWARFDebugFrame.h"
+#include "llvm/DebugInfo/DWARFDebugFrame.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+#include <vector>
using namespace llvm;
using namespace dwarf;
class llvm::FrameEntry {
public:
enum FrameKind {FK_CIE, FK_FDE};
- FrameEntry(FrameKind K, DataExtractor D, uint64_t Offset, uint64_t Length)
- : Kind(K), Data(D), Offset(Offset), Length(Length) {}
+ FrameEntry(FrameKind K, uint64_t Offset, uint64_t Length)
+ : Kind(K), Offset(Offset), Length(Length) {}
virtual ~FrameEntry() {
}
FrameKind getKind() const { return Kind; }
+ virtual uint64_t getOffset() const { return Offset; }
+ /// \brief Parse and store a sequence of CFI instructions from Data,
+ /// 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(DataExtractor Data, 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 The data stream holding the section from which the entry was
- /// parsed.
- DataExtractor Data;
-
/// \brief Offset of this entry in the section.
uint64_t Offset;
/// \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(DataExtractor Data, 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:
+ case DW_CFA_GNU_window_save:
+ // 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 (const auto &Instr : Instructions) {
+ uint8_t Opcode = Instr.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:
// CIEs (and FDEs) are simply container classes, so the only sensible way to
// create them is by providing the full parsed contents in the constructor.
- CIE(DataExtractor D, uint64_t Offset, uint64_t Length, uint8_t Version,
+ CIE(uint64_t Offset, uint64_t Length, uint8_t Version,
SmallString<8> Augmentation, uint64_t CodeAlignmentFactor,
int64_t DataAlignmentFactor, uint64_t ReturnAddressRegister)
- : FrameEntry(FK_CIE, D, Offset, Length), Version(Version),
- Augmentation(Augmentation), CodeAlignmentFactor(CodeAlignmentFactor),
- DataAlignmentFactor(DataAlignmentFactor),
- ReturnAddressRegister(ReturnAddressRegister) {}
+ : FrameEntry(FK_CIE, Offset, Length), Version(Version),
+ Augmentation(std::move(Augmentation)),
+ CodeAlignmentFactor(CodeAlignmentFactor),
+ DataAlignmentFactor(DataAlignmentFactor),
+ ReturnAddressRegister(ReturnAddressRegister) {}
~CIE() {
}
- void dumpHeader(raw_ostream &OS) const {
+ void dumpHeader(raw_ostream &OS) const override {
OS << format("%08x %08x %08x CIE",
(uint32_t)Offset, (uint32_t)Length, DW_CIE_ID)
<< "\n";
OS << format(" Version: %d\n", Version);
OS << " Augmentation: \"" << Augmentation << "\"\n";
- OS << format(" Code alignment factor: %u\n", CodeAlignmentFactor);
- OS << format(" Data alignment factor: %d\n", DataAlignmentFactor);
- OS << format(" Return address column: %d\n", 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";
}
static bool classof(const FrameEntry *FE) {
return FE->getKind() == FK_CIE;
- }
+ }
private:
/// The following fields are defined in section 6.4.1 of the DWARF standard v3
// Each FDE has a CIE it's "linked to". Our FDE contains is constructed with
// an offset to the CIE (provided by parsing the FDE header). The CIE itself
// is obtained lazily once it's actually required.
- FDE(DataExtractor D, uint64_t Offset, uint64_t Length,
- int64_t LinkedCIEOffset, uint64_t InitialLocation, uint64_t AddressRange)
- : FrameEntry(FK_FDE, D, Offset, Length), LinkedCIEOffset(LinkedCIEOffset),
- InitialLocation(InitialLocation), AddressRange(AddressRange),
- LinkedCIE(NULL) {}
+ FDE(uint64_t Offset, uint64_t Length, int64_t LinkedCIEOffset,
+ uint64_t InitialLocation, uint64_t AddressRange)
+ : FrameEntry(FK_FDE, Offset, Length), LinkedCIEOffset(LinkedCIEOffset),
+ InitialLocation(InitialLocation), AddressRange(AddressRange),
+ LinkedCIE(nullptr) {}
~FDE() {
}
- void dumpHeader(raw_ostream &OS) const {
+ void dumpHeader(raw_ostream &OS) const override {
OS << format("%08x %08x %08x FDE ",
- (uint32_t)Offset, (uint32_t)Length, LinkedCIEOffset);
+ (uint32_t)Offset, (uint32_t)Length, (int32_t)LinkedCIEOffset);
OS << format("cie=%08x pc=%08x...%08x\n",
- (uint32_t)LinkedCIEOffset, (uint32_t)InitialLocation,
- InitialLocation + AddressRange);
- OS << "\n";
+ (int32_t)LinkedCIEOffset,
+ (uint32_t)InitialLocation,
+ (uint32_t)InitialLocation + (uint32_t)AddressRange);
if (LinkedCIE) {
OS << format("%p\n", LinkedCIE);
}
static bool classof(const FrameEntry *FE) {
return FE->getKind() == FK_FDE;
- }
-private:
+ }
+private:
/// The following fields are defined in section 6.4.1 of the DWARF standard v3
uint64_t LinkedCIEOffset;
uint64_t InitialLocation;
uint64_t AddressRange;
CIE *LinkedCIE;
};
+} // end anonymous namespace
DWARFDebugFrame::DWARFDebugFrame() {
}
-
DWARFDebugFrame::~DWARFDebugFrame() {
- for (EntryVector::iterator I = Entries.begin(), E = Entries.end();
- I != E; ++I) {
- delete *I;
- }
}
-
static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data,
uint32_t Offset, int Length) {
errs() << "DUMP: ";
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);
+ Entries.emplace_back(new CIE(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);
+ Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
+ InitialLocation, AddressRange));
}
- Offset = EndStructureOffset;
+ Entries.back()->parseInstructions(Data, &Offset, EndStructureOffset);
+
+ if (Offset != EndStructureOffset) {
+ std::string Str;
+ raw_string_ostream OS(Str);
+ OS << format("Parsing entry instructions at %lx failed", StartOffset);
+ report_fatal_error(Str);
+ }
}
}
void DWARFDebugFrame::dump(raw_ostream &OS) const {
OS << "\n";
- for (EntryVector::const_iterator I = Entries.begin(), E = Entries.end();
- I != E; ++I) {
- (*I)->dumpHeader(OS);
+ for (const auto &Entry : Entries) {
+ Entry->dumpHeader(OS);
+ Entry->dumpInstructions(OS);
+ OS << "\n";
}
}