1 //===- RecordSerialization.h ------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef LLVM_DEBUGINFO_CODEVIEW_RECORDSERIALIZATION_H
11 #define LLVM_DEBUGINFO_CODEVIEW_RECORDSERIALIZATION_H
12 
13 #include "llvm/ADT/APSInt.h"
14 #include "llvm/ADT/ArrayRef.h"
15 #include "llvm/ADT/StringRef.h"
16 #include "llvm/DebugInfo/CodeView/CodeView.h"
17 #include "llvm/DebugInfo/CodeView/CodeViewError.h"
18 #include "llvm/Support/BinaryStreamReader.h"
19 #include "llvm/Support/Endian.h"
20 #include "llvm/Support/Error.h"
21 #include <cinttypes>
22 #include <tuple>
23 
24 namespace llvm {
25 namespace codeview {
26 using llvm::support::little32_t;
27 using llvm::support::ulittle16_t;
28 using llvm::support::ulittle32_t;
29 
30 /// Limit on the size of all codeview symbol and type records, including the
31 /// RecordPrefix. MSVC does not emit any records larger than this.
32 enum : unsigned { MaxRecordLength = 0xFF00 };
33 
34 struct RecordPrefix {
35   ulittle16_t RecordLen;  // Record length, starting from &RecordKind.
36   ulittle16_t RecordKind; // Record kind enum (SymRecordKind or TypeRecordKind)
37 };
38 
39 /// Reinterpret a byte array as an array of characters. Does not interpret as
40 /// a C string, as StringRef has several helpers (split) that make that easy.
41 StringRef getBytesAsCharacters(ArrayRef<uint8_t> LeafData);
42 StringRef getBytesAsCString(ArrayRef<uint8_t> LeafData);
43 
consume(BinaryStreamReader & Reader)44 inline Error consume(BinaryStreamReader &Reader) { return Error::success(); }
45 
46 /// Decodes a numeric "leaf" value. These are integer literals encountered in
47 /// the type stream. If the value is positive and less than LF_NUMERIC (1 <<
48 /// 15), it is emitted directly in Data. Otherwise, it has a tag like LF_CHAR
49 /// that indicates the bitwidth and sign of the numeric data.
50 Error consume(BinaryStreamReader &Reader, APSInt &Num);
51 
52 /// Decodes a numeric leaf value that is known to be a particular type.
53 Error consume_numeric(BinaryStreamReader &Reader, uint64_t &Value);
54 
55 /// Decodes signed and unsigned fixed-length integers.
56 Error consume(BinaryStreamReader &Reader, uint32_t &Item);
57 Error consume(BinaryStreamReader &Reader, int32_t &Item);
58 
59 /// Decodes a null terminated string.
60 Error consume(BinaryStreamReader &Reader, StringRef &Item);
61 
62 Error consume(StringRef &Data, APSInt &Num);
63 Error consume(StringRef &Data, uint32_t &Item);
64 
65 /// Decodes an arbitrary object whose layout matches that of the underlying
66 /// byte sequence, and returns a pointer to the object.
consume(BinaryStreamReader & Reader,T * & Item)67 template <typename T> Error consume(BinaryStreamReader &Reader, T *&Item) {
68   return Reader.readObject(Item);
69 }
70 
71 template <typename T, typename U> struct serialize_conditional_impl {
serialize_conditional_implserialize_conditional_impl72   serialize_conditional_impl(T &Item, U Func) : Item(Item), Func(Func) {}
73 
deserializeserialize_conditional_impl74   Error deserialize(BinaryStreamReader &Reader) const {
75     if (!Func())
76       return Error::success();
77     return consume(Reader, Item);
78   }
79 
80   T &Item;
81   U Func;
82 };
83 
84 template <typename T, typename U>
serialize_conditional(T & Item,U Func)85 serialize_conditional_impl<T, U> serialize_conditional(T &Item, U Func) {
86   return serialize_conditional_impl<T, U>(Item, Func);
87 }
88 
89 template <typename T, typename U> struct serialize_array_impl {
serialize_array_implserialize_array_impl90   serialize_array_impl(ArrayRef<T> &Item, U Func) : Item(Item), Func(Func) {}
91 
deserializeserialize_array_impl92   Error deserialize(BinaryStreamReader &Reader) const {
93     return Reader.readArray(Item, Func());
94   }
95 
96   ArrayRef<T> &Item;
97   U Func;
98 };
99 
100 template <typename T> struct serialize_vector_tail_impl {
serialize_vector_tail_implserialize_vector_tail_impl101   serialize_vector_tail_impl(std::vector<T> &Item) : Item(Item) {}
102 
deserializeserialize_vector_tail_impl103   Error deserialize(BinaryStreamReader &Reader) const {
104     T Field;
105     // Stop when we run out of bytes or we hit record padding bytes.
106     while (!Reader.empty() && Reader.peek() < LF_PAD0) {
107       if (auto EC = consume(Reader, Field))
108         return EC;
109       Item.push_back(Field);
110     }
111     return Error::success();
112   }
113 
114   std::vector<T> &Item;
115 };
116 
117 struct serialize_null_term_string_array_impl {
serialize_null_term_string_array_implserialize_null_term_string_array_impl118   serialize_null_term_string_array_impl(std::vector<StringRef> &Item)
119       : Item(Item) {}
120 
deserializeserialize_null_term_string_array_impl121   Error deserialize(BinaryStreamReader &Reader) const {
122     if (Reader.empty())
123       return make_error<CodeViewError>(cv_error_code::insufficient_buffer,
124                                        "Null terminated string is empty!");
125 
126     while (Reader.peek() != 0) {
127       StringRef Field;
128       if (auto EC = Reader.readCString(Field))
129         return EC;
130       Item.push_back(Field);
131     }
132     return Reader.skip(1);
133   }
134 
135   std::vector<StringRef> &Item;
136 };
137 
138 template <typename T> struct serialize_arrayref_tail_impl {
serialize_arrayref_tail_implserialize_arrayref_tail_impl139   serialize_arrayref_tail_impl(ArrayRef<T> &Item) : Item(Item) {}
140 
deserializeserialize_arrayref_tail_impl141   Error deserialize(BinaryStreamReader &Reader) const {
142     uint32_t Count = Reader.bytesRemaining() / sizeof(T);
143     return Reader.readArray(Item, Count);
144   }
145 
146   ArrayRef<T> &Item;
147 };
148 
149 template <typename T> struct serialize_numeric_impl {
serialize_numeric_implserialize_numeric_impl150   serialize_numeric_impl(T &Item) : Item(Item) {}
151 
deserializeserialize_numeric_impl152   Error deserialize(BinaryStreamReader &Reader) const {
153     return consume_numeric(Reader, Item);
154   }
155 
156   T &Item;
157 };
158 
159 template <typename T, typename U>
serialize_array(ArrayRef<T> & Item,U Func)160 serialize_array_impl<T, U> serialize_array(ArrayRef<T> &Item, U Func) {
161   return serialize_array_impl<T, U>(Item, Func);
162 }
163 
164 inline serialize_null_term_string_array_impl
serialize_null_term_string_array(std::vector<StringRef> & Item)165 serialize_null_term_string_array(std::vector<StringRef> &Item) {
166   return serialize_null_term_string_array_impl(Item);
167 }
168 
169 template <typename T>
serialize_array_tail(std::vector<T> & Item)170 serialize_vector_tail_impl<T> serialize_array_tail(std::vector<T> &Item) {
171   return serialize_vector_tail_impl<T>(Item);
172 }
173 
174 template <typename T>
serialize_array_tail(ArrayRef<T> & Item)175 serialize_arrayref_tail_impl<T> serialize_array_tail(ArrayRef<T> &Item) {
176   return serialize_arrayref_tail_impl<T>(Item);
177 }
178 
serialize_numeric(T & Item)179 template <typename T> serialize_numeric_impl<T> serialize_numeric(T &Item) {
180   return serialize_numeric_impl<T>(Item);
181 }
182 
183 // This field is only present in the byte record if the condition is true.  The
184 // condition is evaluated lazily, so it can depend on items that were
185 // deserialized
186 // earlier.
187 #define CV_CONDITIONAL_FIELD(I, C)                                             \
188   serialize_conditional(I, [&]() { return !!(C); })
189 
190 // This is an array of N items, where N is evaluated lazily, so it can refer
191 // to a field deserialized earlier.
192 #define CV_ARRAY_FIELD_N(I, N) serialize_array(I, [&]() { return N; })
193 
194 // This is an array that exhausts the remainder of the input buffer.
195 #define CV_ARRAY_FIELD_TAIL(I) serialize_array_tail(I)
196 
197 // This is an array that consumes null terminated strings until a double null
198 // is encountered.
199 #define CV_STRING_ARRAY_NULL_TERM(I) serialize_null_term_string_array(I)
200 
201 #define CV_NUMERIC_FIELD(I) serialize_numeric(I)
202 
203 template <typename T, typename U>
consume(BinaryStreamReader & Reader,const serialize_conditional_impl<T,U> & Item)204 Error consume(BinaryStreamReader &Reader,
205               const serialize_conditional_impl<T, U> &Item) {
206   return Item.deserialize(Reader);
207 }
208 
209 template <typename T, typename U>
consume(BinaryStreamReader & Reader,const serialize_array_impl<T,U> & Item)210 Error consume(BinaryStreamReader &Reader,
211               const serialize_array_impl<T, U> &Item) {
212   return Item.deserialize(Reader);
213 }
214 
consume(BinaryStreamReader & Reader,const serialize_null_term_string_array_impl & Item)215 inline Error consume(BinaryStreamReader &Reader,
216                      const serialize_null_term_string_array_impl &Item) {
217   return Item.deserialize(Reader);
218 }
219 
220 template <typename T>
consume(BinaryStreamReader & Reader,const serialize_vector_tail_impl<T> & Item)221 Error consume(BinaryStreamReader &Reader,
222               const serialize_vector_tail_impl<T> &Item) {
223   return Item.deserialize(Reader);
224 }
225 
226 template <typename T>
consume(BinaryStreamReader & Reader,const serialize_arrayref_tail_impl<T> & Item)227 Error consume(BinaryStreamReader &Reader,
228               const serialize_arrayref_tail_impl<T> &Item) {
229   return Item.deserialize(Reader);
230 }
231 
232 template <typename T>
consume(BinaryStreamReader & Reader,const serialize_numeric_impl<T> & Item)233 Error consume(BinaryStreamReader &Reader,
234               const serialize_numeric_impl<T> &Item) {
235   return Item.deserialize(Reader);
236 }
237 
238 template <typename T, typename U, typename... Args>
consume(BinaryStreamReader & Reader,T && X,U && Y,Args &&...Rest)239 Error consume(BinaryStreamReader &Reader, T &&X, U &&Y, Args &&... Rest) {
240   if (auto EC = consume(Reader, X))
241     return EC;
242   return consume(Reader, Y, std::forward<Args>(Rest)...);
243 }
244 
245 #define CV_DESERIALIZE(...)                                                    \
246   if (auto EC = consume(__VA_ARGS__))                                          \
247     return std::move(EC);
248 }
249 }
250 
251 #endif
252