DWARF: Add basic support for line tables.

The llvm-dwarfdump output isn't very verbose yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139771 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 195 insertions, 0 deletions

diff --git a/lib/DebugInfo/DWARFDebugLine.h b/lib/DebugInfo/DWARFDebugLine.h
new file mode 100644
index 0000000000..6c3946f4c0
--- /dev/null
+++ b/lib/DebugInfo/DWARFDebugLine.h
@@ -0,0 +1,195 @@
+//===-- DWARFDebugLine.h ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_DWARFDEBUGLINE_H
+#define LLVM_DEBUGINFO_DWARFDEBUGLINE_H
+
+#include "llvm/Support/DataExtractor.h"
+#include <map>
+#include <string>
+#include <vector>
+
+namespace llvm {
+
+class raw_ostream;
+
+class DWARFDebugLine {
+public:
+  struct FileNameEntry {
+    FileNameEntry() : DirIdx(0), ModTime(0), Length(0) {}
+
+    std::string Name;
+    uint64_t DirIdx;
+    uint64_t ModTime;
+    uint64_t Length;
+  };
+
+  struct Prologue {
+    Prologue()
+      : TotalLength(0), Version(0), PrologueLength(0), MinInstLength(0),
+        DefaultIsStmt(0), LineBase(0), LineRange(0), OpcodeBase(0) {}
+
+    // The size in bytes of the statement information for this compilation unit
+    // (not including the total_length field itself).
+    uint32_t TotalLength;
+    // Version identifier for the statement information format.
+    uint16_t Version;
+    // The number of bytes following the prologue_length field to the beginning
+    // of the first byte of the statement program itself.
+    uint32_t PrologueLength;
+    // The size in bytes of the smallest target machine instruction. Statement
+    // program opcodes that alter the address register first multiply their
+    // operands by this value.
+    uint8_t MinInstLength;
+    // The initial value of theis_stmtregister.
+    uint8_t DefaultIsStmt;
+    // This parameter affects the meaning of the special opcodes. See below.
+    int8_t LineBase;
+    // This parameter affects the meaning of the special opcodes. See below.
+    uint8_t LineRange;
+    // The number assigned to the first special opcode.
+    uint8_t OpcodeBase;
+    std::vector<uint8_t> StandardOpcodeLengths;
+    std::vector<std::string> IncludeDirectories;
+    std::vector<FileNameEntry> FileNames;
+
+    // Length of the prologue in bytes.
+    uint32_t getLength() const {
+      return PrologueLength + sizeof(TotalLength) + sizeof(Version) +
+             sizeof(PrologueLength);
+    }
+    // Length of the line table data in bytes (not including the prologue).
+    uint32_t getStatementTableLength() const {
+      return TotalLength + sizeof(TotalLength) - getLength();
+    }
+    int32_t getMaxLineIncrementForSpecialOpcode() const {
+      return LineBase + (int8_t)LineRange - 1;
+    }
+    void dump(raw_ostream &OS) const;
+    void clear() {
+      TotalLength = Version = PrologueLength = 0;
+      MinInstLength = LineBase = LineRange = OpcodeBase = 0;
+      StandardOpcodeLengths.clear();
+      IncludeDirectories.clear();
+      FileNames.clear();
+    }
+    bool getFile(uint32_t file_idx, std::string& file, std::string& dir) const;
+  };
+
+  // Standard .debug_line state machine structure.
+  struct Row {
+    Row(bool default_is_stmt = false) { reset(default_is_stmt); }
+    /// Called after a row is appended to the matrix.
+    void postAppend();
+    void reset(bool default_is_stmt);
+    void dump(raw_ostream &OS) const;
+
+    // The program-counter value corresponding to a machine instruction
+    // generated by the compiler.
+    uint64_t Address;
+    // An unsigned integer indicating a source line number. Lines are numbered
+    // beginning at 1. The compiler may emit the value 0 in cases where an
+    // instruction cannot be attributed to any source line.
+    uint32_t Line;
+    // An unsigned integer indicating a column number within a source line.
+    // Columns are numbered beginning at 1. The value 0 is reserved to indicate
+    // that a statement begins at the 'left edge' of the line.
+    uint16_t Column;
+    // An unsigned integer indicating the identity of the source file
+    // corresponding to a machine instruction.
+    uint16_t File;
+    // An unsigned integer whose value encodes the applicable instruction set
+    // architecture for the current instruction.
+    uint8_t Isa;
+    // A boolean indicating that the current instruction is the beginning of a
+    // statement.
+    uint8_t IsStmt:1,
+            // A boolean indicating that the current instruction is the
+            // beginning of a basic block.
+            BasicBlock:1,
+            // A boolean indicating that the current address is that of the
+            // first byte after the end of a sequence of target machine
+            // instructions.
+            EndSequence:1,
+            // A boolean indicating that the current address is one (of possibly
+            // many) where execution should be suspended for an entry breakpoint
+            // of a function.
+            PrologueEnd:1,
+            // A boolean indicating that the current address is one (of possibly
+            // many) where execution should be suspended for an exit breakpoint
+            // of a function.
+            EpilogueBegin:1;
+  };
+
+  struct LineTable {
+    void appendRow(const DWARFDebugLine::Row &state) { Rows.push_back(state); }
+    void clear() {
+      Prologue.clear();
+      Rows.clear();
+    }
+
+    uint32_t lookupAddress(uint64_t address, uint64_t cu_high_pc) const;
+    void dump(raw_ostream &OS) const;
+
+    struct Prologue Prologue;
+    std::vector<Row> Rows;
+  };
+
+  struct State : public Row, public LineTable {
+    // Special row codes.
+    enum {
+      StartParsingLineTable = 0,
+      DoneParsingLineTable = -1
+    };
+
+    State() : row(0) {}
+
+    virtual void appendRowToMatrix(uint32_t offset);
+    virtual void finalize(uint32_t offset) { row = DoneParsingLineTable; }
+    virtual void reset() { Row::reset(Prologue.DefaultIsStmt); }
+
+    // The row number that starts at zero for the prologue, and increases for
+    // each row added to the matrix.
+    unsigned row;
+  };
+
+  struct DumpingState : public State {
+    DumpingState(raw_ostream &OS) : OS(OS) {}
+    virtual void finalize(uint32_t offset);
+  private:
+    raw_ostream &OS;
+  };
+
+  static bool parsePrologue(DataExtractor debug_line_data, uint32_t *offset_ptr,
+                            Prologue *prologue);
+  /// Parse a single line table (prologue and all rows).
+  static bool parseStatementTable(DataExtractor debug_line_data,
+                                  uint32_t *offset_ptr, State &state);
+
+  /// Parse all information in the debug_line_data into an internal
+  /// representation.
+  void parse(DataExtractor debug_line_data);
+  void parseIfNeeded(DataExtractor debug_line_data) {
+    if (LineTableMap.empty())
+      parse(debug_line_data);
+  }
+  static void dump(DataExtractor debug_line_data, raw_ostream &OS);
+  const LineTable *getLineTable(uint32_t offset) const;
+
+protected:
+  typedef std::map<uint32_t, LineTable> LineTableMapTy;
+  typedef LineTableMapTy::iterator LineTableIter;
+  typedef LineTableMapTy::const_iterator LineTableConstIter;
+
+  LineTableMapTy LineTableMap;
+};
+
+}
+
+#endif