xref: /openbsd-src/gnu/llvm/lld/wasm/InputFiles.h (revision 1a8dbaac879b9f3335ad7fb25429ce63ac1d6bac)
1 //===- InputFiles.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 LLD_WASM_INPUT_FILES_H
10 #define LLD_WASM_INPUT_FILES_H
11 
12 #include "Symbols.h"
13 #include "lld/Common/LLVM.h"
14 #include "llvm/ADT/DenseMap.h"
15 #include "llvm/ADT/DenseSet.h"
16 #include "llvm/LTO/LTO.h"
17 #include "llvm/Object/Archive.h"
18 #include "llvm/Object/Wasm.h"
19 #include "llvm/Support/MemoryBuffer.h"
20 #include <vector>
21 
22 namespace llvm {
23 class TarWriter;
24 }
25 
26 namespace lld {
27 namespace wasm {
28 
29 class InputChunk;
30 class InputFunction;
31 class InputSegment;
32 class InputGlobal;
33 class InputEvent;
34 class InputSection;
35 
36 // If --reproduce option is given, all input files are written
37 // to this tar archive.
38 extern std::unique_ptr<llvm::TarWriter> tar;
39 
40 class InputFile {
41 public:
42   enum Kind {
43     ObjectKind,
44     SharedKind,
45     ArchiveKind,
46     BitcodeKind,
47   };
48 
49   virtual ~InputFile() {}
50 
51   // Returns the filename.
52   StringRef getName() const { return mb.getBufferIdentifier(); }
53 
54   Kind kind() const { return fileKind; }
55 
56   // An archive file name if this file is created from an archive.
57   std::string archiveName;
58 
59   ArrayRef<Symbol *> getSymbols() const { return symbols; }
60 
61   MutableArrayRef<Symbol *> getMutableSymbols() { return symbols; }
62 
63 protected:
64   InputFile(Kind k, MemoryBufferRef m) : mb(m), fileKind(k) {}
65   MemoryBufferRef mb;
66 
67   // List of all symbols referenced or defined by this file.
68   std::vector<Symbol *> symbols;
69 
70 private:
71   const Kind fileKind;
72 };
73 
74 // .a file (ar archive)
75 class ArchiveFile : public InputFile {
76 public:
77   explicit ArchiveFile(MemoryBufferRef m) : InputFile(ArchiveKind, m) {}
78   static bool classof(const InputFile *f) { return f->kind() == ArchiveKind; }
79 
80   void addMember(const llvm::object::Archive::Symbol *sym);
81 
82   void parse();
83 
84 private:
85   std::unique_ptr<llvm::object::Archive> file;
86   llvm::DenseSet<uint64_t> seen;
87 };
88 
89 // .o file (wasm object file)
90 class ObjFile : public InputFile {
91 public:
92   explicit ObjFile(MemoryBufferRef m, StringRef archiveName)
93       : InputFile(ObjectKind, m) {
94     this->archiveName = archiveName;
95   }
96   static bool classof(const InputFile *f) { return f->kind() == ObjectKind; }
97 
98   void parse(bool ignoreComdats = false);
99 
100   // Returns the underlying wasm file.
101   const WasmObjectFile *getWasmObj() const { return wasmObj.get(); }
102 
103   void dumpInfo() const;
104 
105   uint32_t calcNewIndex(const WasmRelocation &reloc) const;
106   uint32_t calcNewValue(const WasmRelocation &reloc) const;
107   uint32_t calcNewAddend(const WasmRelocation &reloc) const;
108   uint32_t calcExpectedValue(const WasmRelocation &reloc) const;
109   Symbol *getSymbol(const WasmRelocation &reloc) const {
110     return symbols[reloc.Index];
111   };
112 
113   const WasmSection *codeSection = nullptr;
114   const WasmSection *dataSection = nullptr;
115 
116   // Maps input type indices to output type indices
117   std::vector<uint32_t> typeMap;
118   std::vector<bool> typeIsUsed;
119   // Maps function indices to table indices
120   std::vector<uint32_t> tableEntries;
121   std::vector<bool> keptComdats;
122   std::vector<InputSegment *> segments;
123   std::vector<InputFunction *> functions;
124   std::vector<InputGlobal *> globals;
125   std::vector<InputEvent *> events;
126   std::vector<InputSection *> customSections;
127   llvm::DenseMap<uint32_t, InputSection *> customSectionsByIndex;
128 
129   Symbol *getSymbol(uint32_t index) const { return symbols[index]; }
130   FunctionSymbol *getFunctionSymbol(uint32_t index) const;
131   DataSymbol *getDataSymbol(uint32_t index) const;
132   GlobalSymbol *getGlobalSymbol(uint32_t index) const;
133   SectionSymbol *getSectionSymbol(uint32_t index) const;
134   EventSymbol *getEventSymbol(uint32_t index) const;
135 
136 private:
137   Symbol *createDefined(const WasmSymbol &sym);
138   Symbol *createUndefined(const WasmSymbol &sym, bool isCalledDirectly);
139 
140   bool isExcludedByComdat(InputChunk *chunk) const;
141 
142   std::unique_ptr<WasmObjectFile> wasmObj;
143 };
144 
145 // .so file.
146 class SharedFile : public InputFile {
147 public:
148   explicit SharedFile(MemoryBufferRef m) : InputFile(SharedKind, m) {}
149   static bool classof(const InputFile *f) { return f->kind() == SharedKind; }
150 };
151 
152 // .bc file
153 class BitcodeFile : public InputFile {
154 public:
155   explicit BitcodeFile(MemoryBufferRef m, StringRef archiveName)
156       : InputFile(BitcodeKind, m) {
157     this->archiveName = archiveName;
158   }
159   static bool classof(const InputFile *f) { return f->kind() == BitcodeKind; }
160 
161   void parse();
162   std::unique_ptr<llvm::lto::InputFile> obj;
163 };
164 
165 inline bool isBitcode(MemoryBufferRef mb) {
166   return identify_magic(mb.getBuffer()) == llvm::file_magic::bitcode;
167 }
168 
169 // Will report a fatal() error if the input buffer is not a valid bitcode
170 // or wasm object file.
171 InputFile *createObjectFile(MemoryBufferRef mb, StringRef archiveName = "");
172 
173 // Opens a given file.
174 llvm::Optional<MemoryBufferRef> readFile(StringRef path);
175 
176 } // namespace wasm
177 
178 std::string toString(const wasm::InputFile *file);
179 
180 } // namespace lld
181 
182 #endif
183