DebugInfo/DWARF/DWARFDebugMacro.h

0001 //===- DWARFDebugMacro.h ----------------------------------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGMACRO_H
0010 #define LLVM_DEBUGINFO_DWARF_DWARFDEBUGMACRO_H
0011
0012 #include "llvm/ADT/SmallVector.h"
0013 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
0014 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
0015 #include "llvm/Support/Error.h"
0016 #include <cstdint>
0017
0018 namespace llvm {
0019
0020 class raw_ostream;
0021
0022 namespace dwarf_linker {
0023 namespace classic {
0024 class DwarfStreamer;
0025 }
0026 } // namespace dwarf_linker
0027
0028 class DWARFDebugMacro {
0029   friend dwarf_linker::classic::DwarfStreamer;
0030   friend dwarf_linker::parallel::CompileUnit;
0031
0032   /// DWARFv5 section 6.3.1 Macro Information Header.
0033   enum HeaderFlagMask {
0034 #define HANDLE_MACRO_FLAG(ID, NAME) MACRO_##NAME = ID,
0035 #include "llvm/BinaryFormat/Dwarf.def"
0036   };
0037   struct MacroHeader {
0038     /// Macro version information number.
0039     uint16_t Version = 0;
0040
0041     /// The bits of the flags field are interpreted as a set of flags, some of
0042     /// which may indicate that additional fields follow. The following flags,
0043     /// beginning with the least significant bit, are defined:
0044     /// offset_size_flag:
0045     ///   If the offset_size_flag is zero, the header is for a 32-bit DWARF
0046     ///   format macro section and all offsets are 4 bytes long; if it is one,
0047     ///   the header is for a 64-bit DWARF format macro section and all offsets
0048     ///   are 8 bytes long.
0049     /// debug_line_offset_flag:
0050     ///   If the debug_line_offset_flag is one, the debug_line_offset field (see
0051     ///   below) is present. If zero, that field is omitted.
0052     /// opcode_operands_table_flag:
0053     ///   If the opcode_operands_table_flag is one, the opcode_operands_table
0054     ///   field (see below) is present. If zero, that field is omitted.
0055     uint8_t Flags = 0;
0056
0057     /// debug_line_offset
0058     ///   An offset in the .debug_line section of the beginning of the line
0059     ///   number information in the containing compilation unit, encoded as a
0060     ///   4-byte offset for a 32-bit DWARF format macro section and an 8-byte
0061     ///   offset for a 64-bit DWARF format macro section.
0062     uint64_t DebugLineOffset;
0063
0064     /// Print the macro header from the debug_macro section.
0065     void dumpMacroHeader(raw_ostream &OS) const;
0066
0067     /// Parse the debug_macro header.
0068     Error parseMacroHeader(DWARFDataExtractor Data, uint64_t *Offset);
0069
0070     /// Get the DWARF format according to the flags.
0071     dwarf::DwarfFormat getDwarfFormat() const;
0072
0073     /// Get the size of a reference according to the DWARF format.
0074     uint8_t getOffsetByteSize() const;
0075   };
0076
0077   /// A single macro entry within a macro list.
0078   struct Entry {
0079     /// The type of the macro entry.
0080     uint32_t Type;
0081     union {
0082       /// The source line where the macro is defined.
0083       uint64_t Line;
0084       /// Vendor extension constant value.
0085       uint64_t ExtConstant;
0086       /// Macro unit import offset.
0087       uint64_t ImportOffset;
0088     };
0089
0090     union {
0091       /// The string (name, value) of the macro entry.
0092       const char *MacroStr;
0093       // An unsigned integer indicating the identity of the source file.
0094       uint64_t File;
0095       /// Vendor extension string.
0096       const char *ExtStr;
0097     };
0098   };
0099
0100   struct MacroList {
0101     // A value 0 in the `Header.Version` field indicates that we're parsing
0102     // a macinfo[.dwo] section which doesn't have header itself, hence
0103     // for that case other fields in the `Header` are uninitialized.
0104     MacroHeader Header;
0105     SmallVector<Entry, 4> Macros;
0106     uint64_t Offset;
0107
0108     /// Whether or not this is a .debug_macro section.
0109     bool IsDebugMacro;
0110   };
0111
0112   /// A list of all the macro entries in the debug_macinfo section.
0113   std::vector<MacroList> MacroLists;
0114
0115 public:
0116   DWARFDebugMacro() = default;
0117
0118   /// Print the macro list found within the debug_macinfo/debug_macro section.
0119   void dump(raw_ostream &OS) const;
0120
0121   Error parseMacro(DWARFUnitVector::compile_unit_range Units,
0122                    DataExtractor StringExtractor,
0123                    DWARFDataExtractor MacroData) {
0124     return parseImpl(Units, StringExtractor, MacroData, /*IsMacro=*/true);
0125   }
0126
0127   Error parseMacinfo(DWARFDataExtractor MacroData) {
0128     return parseImpl(std::nullopt, std::nullopt, MacroData, /*IsMacro=*/false);
0129   }
0130
0131   /// Return whether the section has any entries.
0132   bool empty() const { return MacroLists.empty(); }
0133
0134   bool hasEntryForOffset(uint64_t Offset) const {
0135     for (const MacroList &List : MacroLists)
0136       if (Offset == List.Offset)
0137         return true;
0138
0139     return false;
0140   }
0141
0142 private:
0143   /// Parse the debug_macinfo/debug_macro section accessible via the 'MacroData'
0144   /// parameter.
0145   Error parseImpl(std::optional<DWARFUnitVector::compile_unit_range> Units,
0146                   std::optional<DataExtractor> StringExtractor,
0147                   DWARFDataExtractor Data, bool IsMacro);
0148 };
0149
0150 } // end namespace llvm
0151
0152 #endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGMACRO_H