1 //===- WasmWriter.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_LIB_OBJCOPY_WASM_WASMWRITER_H
10 #define LLVM_LIB_OBJCOPY_WASM_WASMWRITER_H
11 
12 #include "WasmObject.h"
13 #include <cstdint>
14 #include <vector>
15 
16 namespace llvm {
17 namespace objcopy {
18 namespace wasm {
19 
20 class Writer {
21 public:
22   Writer(Object &Obj, raw_ostream &Out) : Obj(Obj), Out(Out) {}
23   Error write();
24 
25 private:
26   using SectionHeader = SmallVector<char, 8>;
27   Object &Obj;
28   raw_ostream &Out;
29   std::vector<SectionHeader> SectionHeaders;
30 
31   /// Generate a wasm section section header for S.
32   /// The header consists of
33   /// * A one-byte section ID (aka the section type).
34   /// * The size of the section contents, encoded as ULEB128.
35   /// * If the section is a custom section (type 0) it also has a name, which is
36   ///   encoded as a length-prefixed string. The encoded section size *includes*
37   ///   this string.
38   /// See https://webassembly.github.io/spec/core/binary/modules.html#sections
39   /// Return the header and store the total size in SectionSize.
40   static SectionHeader createSectionHeader(const Section &S,
41                                            size_t &SectionSize);
42   size_t finalize();
43 };
44 
45 } // end namespace wasm
46 } // end namespace objcopy
47 } // end namespace llvm
48 
49 #endif // LLVM_LIB_OBJCOPY_WASM_WASMWRITER_H
50