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1 //===- DWARFDebugMacro.h ----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_DEBUGINFO_DWARF_DWARFDEBUGMACRO_H
10 #define LLVM_DEBUGINFO_DWARF_DWARFDEBUGMACRO_H
11 
12 #include "llvm/ADT/SmallVector.h"
13 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
14 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
15 #include "llvm/Support/Errc.h"
16 #include "llvm/Support/Error.h"
17 #include <cstdint>
18 
19 namespace llvm {
20 
21 class raw_ostream;
22 
23 class DWARFDebugMacro {
24   /// DWARFv5 section 6.3.1 Macro Information Header.
25   enum HeaderFlagMask {
26 #define HANDLE_MACRO_FLAG(ID, NAME) MACRO_##NAME = ID,
27 #include "llvm/BinaryFormat/Dwarf.def"
28   };
29   struct MacroHeader {
30     /// Macro version information number.
31     uint16_t Version = 0;
32 
33     /// The bits of the flags field are interpreted as a set of flags, some of
34     /// which may indicate that additional fields follow. The following flags,
35     /// beginning with the least significant bit, are defined:
36     /// offset_size_flag:
37     ///   If the offset_size_flag is zero, the header is for a 32-bit DWARF
38     ///   format macro section and all offsets are 4 bytes long; if it is one,
39     ///   the header is for a 64-bit DWARF format macro section and all offsets
40     ///   are 8 bytes long.
41     /// debug_line_offset_flag:
42     ///   If the debug_line_offset_flag is one, the debug_line_offset field (see
43     ///   below) is present. If zero, that field is omitted.
44     /// opcode_operands_table_flag:
45     ///   If the opcode_operands_table_flag is one, the opcode_operands_table
46     ///   field (see below) is present. If zero, that field is omitted.
47     uint8_t Flags = 0;
48 
49     /// debug_line_offset
50     ///   An offset in the .debug_line section of the beginning of the line
51     ///   number information in the containing compilation unit, encoded as a
52     ///   4-byte offset for a 32-bit DWARF format macro section and an 8-byte
53     ///   offset for a 64-bit DWARF format macro section.
54     uint64_t DebugLineOffset;
55 
56     /// Print the macro header from the debug_macro section.
57     void dumpMacroHeader(raw_ostream &OS) const;
58 
59     /// Parse the debug_macro header.
60     Error parseMacroHeader(DWARFDataExtractor Data, uint64_t *Offset);
61 
62     /// Get the DWARF format according to the flags.
63     dwarf::DwarfFormat getDwarfFormat() const;
64 
65     /// Get the size of a reference according to the DWARF format.
66     uint8_t getOffsetByteSize() const;
67   };
68 
69   /// A single macro entry within a macro list.
70   struct Entry {
71     /// The type of the macro entry.
72     uint32_t Type;
73     union {
74       /// The source line where the macro is defined.
75       uint64_t Line;
76       /// Vendor extension constant value.
77       uint64_t ExtConstant;
78       /// Macro unit import offset.
79       uint64_t ImportOffset;
80     };
81 
82     union {
83       /// The string (name, value) of the macro entry.
84       const char *MacroStr;
85       // An unsigned integer indicating the identity of the source file.
86       uint64_t File;
87       /// Vendor extension string.
88       const char *ExtStr;
89     };
90   };
91 
92   struct MacroList {
93     // A value 0 in the `Header.Version` field indicates that we're parsing
94     // a macinfo[.dwo] section which doesn't have header itself, hence
95     // for that case other fields in the `Header` are uninitialized.
96     MacroHeader Header;
97     SmallVector<Entry, 4> Macros;
98     uint64_t Offset;
99 
100     /// Whether or not this is a .debug_macro section.
101     bool IsDebugMacro;
102   };
103 
104   /// A list of all the macro entries in the debug_macinfo section.
105   std::vector<MacroList> MacroLists;
106 
107 public:
108   DWARFDebugMacro() = default;
109 
110   /// Print the macro list found within the debug_macinfo/debug_macro section.
111   void dump(raw_ostream &OS) const;
112 
parseMacro(DWARFUnitVector::compile_unit_range Units,DataExtractor StringExtractor,DWARFDataExtractor MacroData)113   Error parseMacro(DWARFUnitVector::compile_unit_range Units,
114                    DataExtractor StringExtractor,
115                    DWARFDataExtractor MacroData) {
116     return parseImpl(Units, StringExtractor, MacroData, /*IsMacro=*/true);
117   }
118 
parseMacinfo(DWARFDataExtractor MacroData)119   Error parseMacinfo(DWARFDataExtractor MacroData) {
120     return parseImpl(None, None, MacroData, /*IsMacro=*/false);
121   }
122 
123   /// Return whether the section has any entries.
empty()124   bool empty() const { return MacroLists.empty(); }
125 
126 private:
127   /// Parse the debug_macinfo/debug_macro section accessible via the 'MacroData'
128   /// parameter.
129   Error parseImpl(Optional<DWARFUnitVector::compile_unit_range> Units,
130                   Optional<DataExtractor> StringExtractor,
131                   DWARFDataExtractor Data, bool IsMacro);
132 };
133 
134 } // end namespace llvm
135 
136 #endif // LLVM_DEBUGINFO_DWARF_DWARFDEBUGMACRO_H
137