1 //===- DWARFDebugMacro.cpp ------------------------------------------------===//
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 #include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
10 #include "llvm/BinaryFormat/Dwarf.h"
11 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
12 #include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
13 #include "llvm/Support/WithColor.h"
14 #include "llvm/Support/raw_ostream.h"
15 #include <cstdint>
16 
17 using namespace llvm;
18 using namespace dwarf;
19 
20 void DWARFDebugMacro::MacroHeader::dumpMacroHeader(raw_ostream &OS) const {
21   // FIXME: Add support for dumping opcode_operands_table
22   OS << format("macro header: version = 0x%04" PRIx16 ", flags = 0x%02" PRIx8,
23                Version, Flags);
24   if (Flags & MACRO_DEBUG_LINE_OFFSET)
25     OS << format(", debug_line_offset = 0x%04" PRIx64 "\n", DebugLineOffset);
26   else
27     OS << "\n";
28 }
29 
30 void DWARFDebugMacro::dump(raw_ostream &OS) const {
31   unsigned IndLevel = 0;
32   for (const auto &Macros : MacroLists) {
33     OS << format("0x%08" PRIx64 ":\n", Macros.Offset);
34     if (Macros.Header.Version >= 5)
35       Macros.Header.dumpMacroHeader(OS);
36     for (const Entry &E : Macros.Macros) {
37       // There should not be DW_MACINFO_end_file when IndLevel is Zero. However,
38       // this check handles the case of corrupted ".debug_macinfo" section.
39       if (IndLevel > 0)
40         IndLevel -= (E.Type == DW_MACINFO_end_file);
41       // Print indentation.
42       for (unsigned I = 0; I < IndLevel; I++)
43         OS << "  ";
44       IndLevel += (E.Type == DW_MACINFO_start_file);
45       // Based on which version we are handling choose appropriate macro forms.
46       if (Macros.Header.Version >= 5)
47         WithColor(OS, HighlightColor::Macro).get() << MacroString(E.Type);
48       else
49         WithColor(OS, HighlightColor::Macro).get() << MacinfoString(E.Type);
50       switch (E.Type) {
51       default:
52         // Got a corrupted ".debug_macinfo/.debug_macro" section (invalid
53         // macinfo type).
54         break;
55         // debug_macro and debug_macinfo share some common encodings.
56         // DW_MACRO_define     == DW_MACINFO_define
57         // DW_MACRO_undef      == DW_MACINFO_undef
58         // DW_MACRO_start_file == DW_MACINFO_start_file
59         // DW_MACRO_end_file   == DW_MACINFO_end_file
60         // For readability/uniformity we are using DW_MACRO_*.
61       case DW_MACRO_define:
62       case DW_MACRO_undef:
63       case DW_MACRO_define_strp:
64       case DW_MACRO_undef_strp:
65         OS << " - lineno: " << E.Line;
66         OS << " macro: " << E.MacroStr;
67         break;
68       case DW_MACRO_start_file:
69         OS << " - lineno: " << E.Line;
70         OS << " filenum: " << E.File;
71         break;
72       case DW_MACRO_end_file:
73         break;
74       case DW_MACINFO_vendor_ext:
75         OS << " - constant: " << E.ExtConstant;
76         OS << " string: " << E.ExtStr;
77         break;
78       }
79       OS << "\n";
80     }
81   }
82 }
83 
84 Error DWARFDebugMacro::parse(DataExtractor StringExtractor,
85                              DWARFDataExtractor Data, bool IsMacro) {
86   uint64_t Offset = 0;
87   MacroList *M = nullptr;
88   while (Data.isValidOffset(Offset)) {
89     if (!M) {
90       MacroLists.emplace_back();
91       M = &MacroLists.back();
92       M->Offset = Offset;
93       if (IsMacro) {
94         auto Err = M->Header.parseMacroHeader(Data, &Offset);
95         if (Err)
96           return Err;
97       }
98     }
99     // A macro list entry consists of:
100     M->Macros.emplace_back();
101     Entry &E = M->Macros.back();
102     // 1. Macinfo type
103     E.Type = Data.getULEB128(&Offset);
104 
105     if (E.Type == 0) {
106       // Reached end of a ".debug_macinfo/debug_macro" section contribution.
107       M = nullptr;
108       continue;
109     }
110 
111     switch (E.Type) {
112     default:
113       // Got a corrupted ".debug_macinfo" section (invalid macinfo type).
114       // Push the corrupted entry to the list and halt parsing.
115       E.Type = DW_MACINFO_invalid;
116       return Error::success();
117     // debug_macro and debug_macinfo share some common encodings.
118     // DW_MACRO_define     == DW_MACINFO_define
119     // DW_MACRO_undef      == DW_MACINFO_undef
120     // DW_MACRO_start_file == DW_MACINFO_start_file
121     // DW_MACRO_end_file   == DW_MACINFO_end_file
122     // For readibility/uniformity we are using DW_MACRO_*.
123     case DW_MACRO_define:
124     case DW_MACRO_undef:
125       // 2. Source line
126       E.Line = Data.getULEB128(&Offset);
127       // 3. Macro string
128       E.MacroStr = Data.getCStr(&Offset);
129       break;
130     case DW_MACRO_define_strp:
131     case DW_MACRO_undef_strp: {
132       uint64_t StrOffset = 0;
133       // 2. Source line
134       E.Line = Data.getULEB128(&Offset);
135       // 3. Macro string
136       // FIXME: Add support for DWARF64
137       StrOffset = Data.getRelocatedValue(/*OffsetSize=*/4, &Offset);
138       E.MacroStr = StringExtractor.getCStr(&StrOffset);
139       break;
140     }
141     case DW_MACRO_start_file:
142       // 2. Source line
143       E.Line = Data.getULEB128(&Offset);
144       // 3. Source file id
145       E.File = Data.getULEB128(&Offset);
146       break;
147     case DW_MACRO_end_file:
148       break;
149     case DW_MACINFO_vendor_ext:
150       // 2. Vendor extension constant
151       E.ExtConstant = Data.getULEB128(&Offset);
152       // 3. Vendor extension string
153       E.ExtStr = Data.getCStr(&Offset);
154       break;
155     }
156   }
157   return Error::success();
158 }
159 
160 Error DWARFDebugMacro::MacroHeader::parseMacroHeader(DWARFDataExtractor Data,
161                                                      uint64_t *Offset) {
162   Version = Data.getU16(Offset);
163   uint8_t FlagData = Data.getU8(Offset);
164   // FIXME: Add support for DWARF64
165   if (FlagData & MACRO_OFFSET_SIZE)
166     return createStringError(errc::not_supported, "DWARF64 is not supported");
167 
168   // FIXME: Add support for parsing opcode_operands_table
169   if (FlagData & MACRO_OPCODE_OPERANDS_TABLE)
170     return createStringError(errc::not_supported,
171                              "opcode_operands_table is not supported");
172   Flags = FlagData;
173   if (Flags & MACRO_DEBUG_LINE_OFFSET)
174     DebugLineOffset = Data.getU32(Offset);
175   return Error::success();
176 }
177