1 //===- RecordSerialization.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_CODEVIEW_RECORDSERIALIZATION_H
10 #define LLVM_DEBUGINFO_CODEVIEW_RECORDSERIALIZATION_H
11 
12 #include "llvm/ADT/ArrayRef.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/DebugInfo/CodeView/CodeView.h"
15 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
16 #include "llvm/Support/BinaryStreamReader.h"
17 #include "llvm/Support/Endian.h"
18 #include "llvm/Support/Error.h"
19 #include <cinttypes>
20 
21 namespace llvm {
22 class APSInt;
23 namespace codeview {
24 using llvm::support::little32_t;
25 using llvm::support::ulittle16_t;
26 using llvm::support::ulittle32_t;
27 
28 /// Limit on the size of all codeview symbol and type records, including the
29 /// RecordPrefix. MSVC does not emit any records larger than this.
30 enum : unsigned { MaxRecordLength = 0xFF00 };
31 
32 struct RecordPrefix {
33   RecordPrefix() = default;
34   explicit RecordPrefix(uint16_t Kind) : RecordLen(2), RecordKind(Kind) {}
35 
36   ulittle16_t RecordLen;  // Record length, starting from &RecordKind.
37   ulittle16_t RecordKind; // Record kind enum (SymRecordKind or TypeRecordKind)
38 };
39 
40 /// Reinterpret a byte array as an array of characters. Does not interpret as
41 /// a C string, as StringRef has several helpers (split) that make that easy.
42 StringRef getBytesAsCharacters(ArrayRef<uint8_t> LeafData);
43 StringRef getBytesAsCString(ArrayRef<uint8_t> LeafData);
44 
45 inline Error consume(BinaryStreamReader &Reader) { return Error::success(); }
46 
47 /// Decodes a numeric "leaf" value. These are integer literals encountered in
48 /// the type stream. If the value is positive and less than LF_NUMERIC (1 <<
49 /// 15), it is emitted directly in Data. Otherwise, it has a tag like LF_CHAR
50 /// that indicates the bitwidth and sign of the numeric data.
51 Error consume(BinaryStreamReader &Reader, APSInt &Num);
52 
53 /// Decodes a numeric leaf value that is known to be a particular type.
54 Error consume_numeric(BinaryStreamReader &Reader, uint64_t &Value);
55 
56 /// Decodes signed and unsigned fixed-length integers.
57 Error consume(BinaryStreamReader &Reader, uint32_t &Item);
58 Error consume(BinaryStreamReader &Reader, int32_t &Item);
59 
60 /// Decodes a null terminated string.
61 Error consume(BinaryStreamReader &Reader, StringRef &Item);
62 
63 Error consume(StringRef &Data, APSInt &Num);
64 Error consume(StringRef &Data, uint32_t &Item);
65 
66 /// Decodes an arbitrary object whose layout matches that of the underlying
67 /// byte sequence, and returns a pointer to the object.
68 template <typename T> Error consume(BinaryStreamReader &Reader, T *&Item) {
69   return Reader.readObject(Item);
70 }
71 
72 template <typename T, typename U> struct serialize_conditional_impl {
73   serialize_conditional_impl(T &Item, U Func) : Item(Item), Func(Func) {}
74 
75   Error deserialize(BinaryStreamReader &Reader) const {
76     if (!Func())
77       return Error::success();
78     return consume(Reader, Item);
79   }
80 
81   T &Item;
82   U Func;
83 };
84 
85 template <typename T, typename U>
86 serialize_conditional_impl<T, U> serialize_conditional(T &Item, U Func) {
87   return serialize_conditional_impl<T, U>(Item, Func);
88 }
89 
90 template <typename T, typename U> struct serialize_array_impl {
91   serialize_array_impl(ArrayRef<T> &Item, U Func) : Item(Item), Func(Func) {}
92 
93   Error deserialize(BinaryStreamReader &Reader) const {
94     return Reader.readArray(Item, Func());
95   }
96 
97   ArrayRef<T> &Item;
98   U Func;
99 };
100 
101 template <typename T> struct serialize_vector_tail_impl {
102   serialize_vector_tail_impl(std::vector<T> &Item) : Item(Item) {}
103 
104   Error deserialize(BinaryStreamReader &Reader) const {
105     T Field;
106     // Stop when we run out of bytes or we hit record padding bytes.
107     while (!Reader.empty() && Reader.peek() < LF_PAD0) {
108       if (auto EC = consume(Reader, Field))
109         return EC;
110       Item.push_back(Field);
111     }
112     return Error::success();
113   }
114 
115   std::vector<T> &Item;
116 };
117 
118 struct serialize_null_term_string_array_impl {
119   serialize_null_term_string_array_impl(std::vector<StringRef> &Item)
120       : Item(Item) {}
121 
122   Error deserialize(BinaryStreamReader &Reader) const {
123     if (Reader.empty())
124       return make_error<CodeViewError>(cv_error_code::insufficient_buffer,
125                                        "Null terminated string is empty!");
126 
127     while (Reader.peek() != 0) {
128       StringRef Field;
129       if (auto EC = Reader.readCString(Field))
130         return EC;
131       Item.push_back(Field);
132     }
133     return Reader.skip(1);
134   }
135 
136   std::vector<StringRef> &Item;
137 };
138 
139 template <typename T> struct serialize_arrayref_tail_impl {
140   serialize_arrayref_tail_impl(ArrayRef<T> &Item) : Item(Item) {}
141 
142   Error deserialize(BinaryStreamReader &Reader) const {
143     uint32_t Count = Reader.bytesRemaining() / sizeof(T);
144     return Reader.readArray(Item, Count);
145   }
146 
147   ArrayRef<T> &Item;
148 };
149 
150 template <typename T> struct serialize_numeric_impl {
151   serialize_numeric_impl(T &Item) : Item(Item) {}
152 
153   Error deserialize(BinaryStreamReader &Reader) const {
154     return consume_numeric(Reader, Item);
155   }
156 
157   T &Item;
158 };
159 
160 template <typename T, typename U>
161 serialize_array_impl<T, U> serialize_array(ArrayRef<T> &Item, U Func) {
162   return serialize_array_impl<T, U>(Item, Func);
163 }
164 
165 inline serialize_null_term_string_array_impl
166 serialize_null_term_string_array(std::vector<StringRef> &Item) {
167   return serialize_null_term_string_array_impl(Item);
168 }
169 
170 template <typename T>
171 serialize_vector_tail_impl<T> serialize_array_tail(std::vector<T> &Item) {
172   return serialize_vector_tail_impl<T>(Item);
173 }
174 
175 template <typename T>
176 serialize_arrayref_tail_impl<T> serialize_array_tail(ArrayRef<T> &Item) {
177   return serialize_arrayref_tail_impl<T>(Item);
178 }
179 
180 template <typename T> serialize_numeric_impl<T> serialize_numeric(T &Item) {
181   return serialize_numeric_impl<T>(Item);
182 }
183 
184 template <typename T, typename U>
185 Error consume(BinaryStreamReader &Reader,
186               const serialize_conditional_impl<T, U> &Item) {
187   return Item.deserialize(Reader);
188 }
189 
190 template <typename T, typename U>
191 Error consume(BinaryStreamReader &Reader,
192               const serialize_array_impl<T, U> &Item) {
193   return Item.deserialize(Reader);
194 }
195 
196 inline Error consume(BinaryStreamReader &Reader,
197                      const serialize_null_term_string_array_impl &Item) {
198   return Item.deserialize(Reader);
199 }
200 
201 template <typename T>
202 Error consume(BinaryStreamReader &Reader,
203               const serialize_vector_tail_impl<T> &Item) {
204   return Item.deserialize(Reader);
205 }
206 
207 template <typename T>
208 Error consume(BinaryStreamReader &Reader,
209               const serialize_arrayref_tail_impl<T> &Item) {
210   return Item.deserialize(Reader);
211 }
212 
213 template <typename T>
214 Error consume(BinaryStreamReader &Reader,
215               const serialize_numeric_impl<T> &Item) {
216   return Item.deserialize(Reader);
217 }
218 
219 template <typename T, typename U, typename... Args>
220 Error consume(BinaryStreamReader &Reader, T &&X, U &&Y, Args &&... Rest) {
221   if (auto EC = consume(Reader, X))
222     return EC;
223   return consume(Reader, Y, std::forward<Args>(Rest)...);
224 }
225 
226 }
227 }
228 
229 #endif
230