lld/wasm/WriterUtils.cpp

   1 //===- WriterUtils.cpp ----------------------------------------------------===//
   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 #include "WriterUtils.h"
  10 #include "lld/Common/ErrorHandler.h"
  11 #include "llvm/ADT/StringExtras.h"
  12 #include "llvm/Support/Debug.h"
  13 #include "llvm/Support/EndianStream.h"
  14 #include "llvm/Support/LEB128.h"
  15
  16 #define DEBUG_TYPE "lld"
  17
  18 using namespace llvm;
  19 using namespace llvm::wasm;
  20
  21 namespace lld {
  22 std::string toString(ValType type) {
  23   switch (type) {
  24   case ValType::I32:
  25     return "i32";
  26   case ValType::I64:
  27     return "i64";
  28   case ValType::F32:
  29     return "f32";
  30   case ValType::F64:
  31     return "f64";
  32   case ValType::V128:
  33     return "v128";
  34   case ValType::FUNCREF:
  35     return "funcref";
  36   case ValType::EXTERNREF:
  37     return "externref";
  38   }
  39   llvm_unreachable("Invalid wasm::ValType");
  40 }
  41
  42 std::string toString(const WasmSignature &sig) {
  43   SmallString<128> s("(");
  44   for (ValType type : sig.Params) {
  45     if (s.size() != 1)
  46       s += ", ";
  47     s += toString(type);
  48   }
  49   s += ") -> ";
  50   if (sig.Returns.empty())
  51     s += "void";
  52   else
  53     s += toString(sig.Returns[0]);
  54   return std::string(s.str());
  55 }
  56
  57 std::string toString(const WasmGlobalType &type) {
  58   return (type.Mutable ? "var " : "const ") +
  59          toString(static_cast<ValType>(type.Type));
  60 }
  61
  62 static std::string toString(const llvm::wasm::WasmLimits &limits) {
  63   std::string ret;
  64   ret += "flags=0x" + std::to_string(limits.Flags);
  65   ret += "; min=" + std::to_string(limits.Minimum);
  66   if (limits.Flags & WASM_LIMITS_FLAG_HAS_MAX)
  67     ret += "; max=" + std::to_string(limits.Maximum);
  68   return ret;
  69 }
  70
  71 std::string toString(const WasmTableType &type) {
  72   SmallString<128> ret("");
  73   return "type=" + toString(static_cast<ValType>(type.ElemType)) +
  74          "; limits=[" + toString(type.Limits) + "]";
  75 }
  76
  77 namespace wasm {
  78 #ifdef LLVM_DEBUG
  79 void debugWrite(uint64_t offset, const Twine &msg) {
  80   LLVM_DEBUG(dbgs() << format("  | %08lld: ", offset) << msg << "\n");
  81 }
  82 #endif
  83
  84 void writeUleb128(raw_ostream &os, uint64_t number, const Twine &msg) {
  85   debugWrite(os.tell(), msg + "[" + utohexstr(number) + "]");
  86   encodeULEB128(number, os);
  87 }
  88
  89 void writeSleb128(raw_ostream &os, int64_t number, const Twine &msg) {
  90   debugWrite(os.tell(), msg + "[" + utohexstr(number) + "]");
  91   encodeSLEB128(number, os);
  92 }
  93
  94 void writeBytes(raw_ostream &os, const char *bytes, size_t count,
  95                       const Twine &msg) {
  96   debugWrite(os.tell(), msg + " [data[" + Twine(count) + "]]");
  97   os.write(bytes, count);
  98 }
  99
 100 void writeStr(raw_ostream &os, StringRef string, const Twine &msg) {
 101   debugWrite(os.tell(),
 102              msg + " [str[" + Twine(string.size()) + "]: " + string + "]");
 103   encodeULEB128(string.size(), os);
 104   os.write(string.data(), string.size());
 105 }
 106
 107 void writeU8(raw_ostream &os, uint8_t byte, const Twine &msg) {
 108   debugWrite(os.tell(), msg + " [0x" + utohexstr(byte) + "]");
 109   os << byte;
 110 }
 111
 112 void writeU32(raw_ostream &os, uint32_t number, const Twine &msg) {
 113   debugWrite(os.tell(), msg + "[0x" + utohexstr(number) + "]");
 114   support::endian::write(os, number, llvm::endianness::little);
 115 }
 116
 117 void writeU64(raw_ostream &os, uint64_t number, const Twine &msg) {
 118   debugWrite(os.tell(), msg + "[0x" + utohexstr(number) + "]");
 119   support::endian::write(os, number, llvm::endianness::little);
 120 }
 121
 122 void writeValueType(raw_ostream &os, ValType type, const Twine &msg) {
 123   writeU8(os, static_cast<uint8_t>(type),
 124           msg + "[type: " + toString(type) + "]");
 125 }
 126
 127 void writeSig(raw_ostream &os, const WasmSignature &sig) {
 128   writeU8(os, WASM_TYPE_FUNC, "signature type");
 129   writeUleb128(os, sig.Params.size(), "param Count");
 130   for (ValType paramType : sig.Params) {
 131     writeValueType(os, paramType, "param type");
 132   }
 133   writeUleb128(os, sig.Returns.size(), "result Count");
 134   for (ValType returnType : sig.Returns) {
 135     writeValueType(os, returnType, "result type");
 136   }
 137 }
 138
 139 void writeI32Const(raw_ostream &os, int32_t number, const Twine &msg) {
 140   writeU8(os, WASM_OPCODE_I32_CONST, "i32.const");
 141   writeSleb128(os, number, msg);
 142 }
 143
 144 void writeI64Const(raw_ostream &os, int64_t number, const Twine &msg) {
 145   writeU8(os, WASM_OPCODE_I64_CONST, "i64.const");
 146   writeSleb128(os, number, msg);
 147 }
 148
 149 void writePtrConst(raw_ostream &os, int64_t number, bool is64,
 150                    const Twine &msg) {
 151   if (is64)
 152     writeI64Const(os, number, msg);
 153   else
 154     writeI32Const(os, static_cast<int32_t>(number), msg);
 155 }
 156
 157 void writeMemArg(raw_ostream &os, uint32_t alignment, uint64_t offset) {
 158   writeUleb128(os, alignment, "alignment");
 159   writeUleb128(os, offset, "offset");
 160 }
 161
 162 void writeInitExpr(raw_ostream &os, const WasmInitExpr &initExpr) {
 163   assert(!initExpr.Extended);
 164   writeInitExprMVP(os, initExpr.Inst);
 165 }
 166
 167 void writeInitExprMVP(raw_ostream &os, const WasmInitExprMVP &initExpr) {
 168   writeU8(os, initExpr.Opcode, "opcode");
 169   switch (initExpr.Opcode) {
 170   case WASM_OPCODE_I32_CONST:
 171     writeSleb128(os, initExpr.Value.Int32, "literal (i32)");
 172     break;
 173   case WASM_OPCODE_I64_CONST:
 174     writeSleb128(os, initExpr.Value.Int64, "literal (i64)");
 175     break;
 176   case WASM_OPCODE_F32_CONST:
 177     writeU32(os, initExpr.Value.Float32, "literal (f32)");
 178     break;
 179   case WASM_OPCODE_F64_CONST:
 180     writeU64(os, initExpr.Value.Float64, "literal (f64)");
 181     break;
 182   case WASM_OPCODE_GLOBAL_GET:
 183     writeUleb128(os, initExpr.Value.Global, "literal (global index)");
 184     break;
 185   case WASM_OPCODE_REF_NULL:
 186     writeValueType(os, ValType::EXTERNREF, "literal (externref type)");
 187     break;
 188   default:
 189     fatal("unknown opcode in init expr: " + Twine(initExpr.Opcode));
 190   }
 191   writeU8(os, WASM_OPCODE_END, "opcode:end");
 192 }
 193
 194 void writeLimits(raw_ostream &os, const WasmLimits &limits) {
 195   writeU8(os, limits.Flags, "limits flags");
 196   writeUleb128(os, limits.Minimum, "limits min");
 197   if (limits.Flags & WASM_LIMITS_FLAG_HAS_MAX)
 198     writeUleb128(os, limits.Maximum, "limits max");
 199 }
 200
 201 void writeGlobalType(raw_ostream &os, const WasmGlobalType &type) {
 202   // TODO: Update WasmGlobalType to use ValType and remove this cast.
 203   writeValueType(os, ValType(type.Type), "global type");
 204   writeU8(os, type.Mutable, "global mutable");
 205 }
 206
 207 void writeTableType(raw_ostream &os, const WasmTableType &type) {
 208   writeValueType(os, ValType(type.ElemType), "table type");
 209   writeLimits(os, type.Limits);
 210 }
 211
 212 void writeImport(raw_ostream &os, const WasmImport &import) {
 213   writeStr(os, import.Module, "import module name");
 214   writeStr(os, import.Field, "import field name");
 215   writeU8(os, import.Kind, "import kind");
 216   switch (import.Kind) {
 217   case WASM_EXTERNAL_FUNCTION:
 218     writeUleb128(os, import.SigIndex, "import sig index");
 219     break;
 220   case WASM_EXTERNAL_GLOBAL:
 221     writeGlobalType(os, import.Global);
 222     break;
 223   case WASM_EXTERNAL_TAG:
 224     writeUleb128(os, 0, "tag attribute"); // Reserved "attribute" field
 225     writeUleb128(os, import.SigIndex, "import sig index");
 226     break;
 227   case WASM_EXTERNAL_MEMORY:
 228     writeLimits(os, import.Memory);
 229     break;
 230   case WASM_EXTERNAL_TABLE:
 231     writeTableType(os, import.Table);
 232     break;
 233   default:
 234     fatal("unsupported import type: " + Twine(import.Kind));
 235   }
 236 }
 237
 238 void writeExport(raw_ostream &os, const WasmExport &export_) {
 239   writeStr(os, export_.Name, "export name");
 240   writeU8(os, export_.Kind, "export kind");
 241   switch (export_.Kind) {
 242   case WASM_EXTERNAL_FUNCTION:
 243     writeUleb128(os, export_.Index, "function index");
 244     break;
 245   case WASM_EXTERNAL_GLOBAL:
 246     writeUleb128(os, export_.Index, "global index");
 247     break;
 248   case WASM_EXTERNAL_TAG:
 249     writeUleb128(os, export_.Index, "tag index");
 250     break;
 251   case WASM_EXTERNAL_MEMORY:
 252     writeUleb128(os, export_.Index, "memory index");
 253     break;
 254   case WASM_EXTERNAL_TABLE:
 255     writeUleb128(os, export_.Index, "table index");
 256     break;
 257   default:
 258     fatal("unsupported export type: " + Twine(export_.Kind));
 259   }
 260 }
 261
 262 } // namespace wasm
 263 } // namespace lld