Move DebugInfo to DebugInfo/DWARF.
In preparation for adding PDB support to LLVM, this moves the
DWARF parsing code to its own subdirectory under DebugInfo, and
renames LLVMDebugInfo to LLVMDebugInfoDWARF.
This is purely a mechanical / build system change.
Differential Revision: http://reviews.llvm.org/D7269
Reviewed by: Eric Christopher
llvm-svn: 227586
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
new file mode 100644
index 0000000..b7a0dd3
--- /dev/null
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
@@ -0,0 +1,374 @@
+//===-- DWARFDebugFrame.h - Parsing of .debug_frame -------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/DWARF/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;
+
+
+/// \brief Abstract frame entry defining the common interface concrete
+/// entries implement.
+class llvm::FrameEntry {
+public:
+ enum FrameKind {FK_CIE, FK_FDE};
+ 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 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(uint64_t Offset, uint64_t Length, uint8_t Version,
+ SmallString<8> Augmentation, uint64_t CodeAlignmentFactor,
+ int64_t DataAlignmentFactor, uint64_t 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 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",
+ (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
+ uint8_t Version;
+ SmallString<8> Augmentation;
+ uint64_t CodeAlignmentFactor;
+ int64_t DataAlignmentFactor;
+ uint64_t ReturnAddressRegister;
+};
+
+
+/// \brief DWARF Frame Description Entry (FDE)
+class FDE : public FrameEntry {
+public:
+ // 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(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 override {
+ OS << format("%08x %08x %08x FDE ",
+ (uint32_t)Offset, (uint32_t)Length, (int32_t)LinkedCIEOffset);
+ OS << format("cie=%08x pc=%08x...%08x\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:
+ /// 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() {
+}
+
+static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data,
+ uint32_t Offset, int Length) {
+ errs() << "DUMP: ";
+ for (int i = 0; i < Length; ++i) {
+ uint8_t c = Data.getU8(&Offset);
+ errs().write_hex(c); errs() << " ";
+ }
+ errs() << "\n";
+}
+
+
+void DWARFDebugFrame::parse(DataExtractor Data) {
+ uint32_t Offset = 0;
+
+ while (Data.isValidOffset(Offset)) {
+ uint32_t StartOffset = Offset;
+
+ bool IsDWARF64 = false;
+ uint64_t Length = Data.getU32(&Offset);
+ uint64_t Id;
+
+ if (Length == UINT32_MAX) {
+ // DWARF-64 is distinguished by the first 32 bits of the initial length
+ // field being 0xffffffff. Then, the next 64 bits are the actual entry
+ // length.
+ IsDWARF64 = true;
+ Length = Data.getU64(&Offset);
+ }
+
+ // At this point, Offset points to the next field after Length.
+ // Length is the structure size excluding itself. Compute an offset one
+ // past the end of the structure (needed to know how many instructions to
+ // read).
+ // TODO: For honest DWARF64 support, DataExtractor will have to treat
+ // offset_ptr as uint64_t*
+ uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length);
+
+ // The Id field's size depends on the DWARF format
+ Id = Data.getUnsigned(&Offset, IsDWARF64 ? 8 : 4);
+ bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID);
+
+ if (IsCIE) {
+ // Note: this is specifically DWARFv3 CIE header structure. It was
+ // 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);
+
+ 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);
+
+ Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
+ InitialLocation, AddressRange));
+ }
+
+ 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 (const auto &Entry : Entries) {
+ Entry->dumpHeader(OS);
+ Entry->dumpInstructions(OS);
+ OS << "\n";
+ }
+}
+