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