llvm-capstone/lld/wasm/WriterUtils.cpp
Sam Clegg 79aad89d8d [WebAssembly] Add support for externalref to MC and wasm-ld
This allows code for handling externref values to be processed by the
assembler and linker.

Differential Revision: https://reviews.llvm.org/D81977
2020-06-22 15:57:24 -07:00

252 lines
7.4 KiB
C++

//===- WriterUtils.cpp ----------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "WriterUtils.h"
#include "lld/Common/ErrorHandler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/LEB128.h"
#define DEBUG_TYPE "lld"
using namespace llvm;
using namespace llvm::wasm;
namespace lld {
std::string toString(ValType type) {
switch (type) {
case ValType::I32:
return "i32";
case ValType::I64:
return "i64";
case ValType::F32:
return "f32";
case ValType::F64:
return "f64";
case ValType::V128:
return "v128";
case ValType::EXNREF:
return "exnref";
case ValType::EXTERNREF:
return "externref";
}
llvm_unreachable("Invalid wasm::ValType");
}
std::string toString(const WasmSignature &sig) {
SmallString<128> s("(");
for (ValType type : sig.Params) {
if (s.size() != 1)
s += ", ";
s += toString(type);
}
s += ") -> ";
if (sig.Returns.empty())
s += "void";
else
s += toString(sig.Returns[0]);
return std::string(s.str());
}
std::string toString(const WasmGlobalType &type) {
return (type.Mutable ? "var " : "const ") +
toString(static_cast<ValType>(type.Type));
}
std::string toString(const WasmEventType &type) {
if (type.Attribute == WASM_EVENT_ATTRIBUTE_EXCEPTION)
return "exception";
return "unknown";
}
namespace wasm {
void debugWrite(uint64_t offset, const Twine &msg) {
LLVM_DEBUG(dbgs() << format(" | %08lld: ", offset) << msg << "\n");
}
void writeUleb128(raw_ostream &os, uint64_t number, const Twine &msg) {
debugWrite(os.tell(), msg + "[" + utohexstr(number) + "]");
encodeULEB128(number, os);
}
void writeSleb128(raw_ostream &os, int64_t number, const Twine &msg) {
debugWrite(os.tell(), msg + "[" + utohexstr(number) + "]");
encodeSLEB128(number, os);
}
void writeBytes(raw_ostream &os, const char *bytes, size_t count,
const Twine &msg) {
debugWrite(os.tell(), msg + " [data[" + Twine(count) + "]]");
os.write(bytes, count);
}
void writeStr(raw_ostream &os, StringRef string, const Twine &msg) {
debugWrite(os.tell(),
msg + " [str[" + Twine(string.size()) + "]: " + string + "]");
encodeULEB128(string.size(), os);
os.write(string.data(), string.size());
}
void writeU8(raw_ostream &os, uint8_t byte, const Twine &msg) {
debugWrite(os.tell(), msg + " [0x" + utohexstr(byte) + "]");
os << byte;
}
void writeU32(raw_ostream &os, uint32_t number, const Twine &msg) {
debugWrite(os.tell(), msg + "[0x" + utohexstr(number) + "]");
support::endian::write(os, number, support::little);
}
void writeU64(raw_ostream &os, uint64_t number, const Twine &msg) {
debugWrite(os.tell(), msg + "[0x" + utohexstr(number) + "]");
support::endian::write(os, number, support::little);
}
void writeValueType(raw_ostream &os, ValType type, const Twine &msg) {
writeU8(os, static_cast<uint8_t>(type),
msg + "[type: " + toString(type) + "]");
}
void writeSig(raw_ostream &os, const WasmSignature &sig) {
writeU8(os, WASM_TYPE_FUNC, "signature type");
writeUleb128(os, sig.Params.size(), "param Count");
for (ValType paramType : sig.Params) {
writeValueType(os, paramType, "param type");
}
writeUleb128(os, sig.Returns.size(), "result Count");
if (sig.Returns.size()) {
writeValueType(os, sig.Returns[0], "result type");
}
}
void writeI32Const(raw_ostream &os, int32_t number, const Twine &msg) {
writeU8(os, WASM_OPCODE_I32_CONST, "i32.const");
writeSleb128(os, number, msg);
}
void writeI64Const(raw_ostream &os, int64_t number, const Twine &msg) {
writeU8(os, WASM_OPCODE_I64_CONST, "i64.const");
writeSleb128(os, number, msg);
}
void writeMemArg(raw_ostream &os, uint32_t alignment, uint64_t offset) {
writeUleb128(os, alignment, "alignment");
writeUleb128(os, offset, "offset");
}
void writeInitExpr(raw_ostream &os, const WasmInitExpr &initExpr) {
writeU8(os, initExpr.Opcode, "opcode");
switch (initExpr.Opcode) {
case WASM_OPCODE_I32_CONST:
writeSleb128(os, initExpr.Value.Int32, "literal (i32)");
break;
case WASM_OPCODE_I64_CONST:
writeSleb128(os, initExpr.Value.Int64, "literal (i64)");
break;
case WASM_OPCODE_F32_CONST:
writeU32(os, initExpr.Value.Float32, "literal (f32)");
break;
case WASM_OPCODE_F64_CONST:
writeU64(os, initExpr.Value.Float64, "literal (f64)");
break;
case WASM_OPCODE_GLOBAL_GET:
writeUleb128(os, initExpr.Value.Global, "literal (global index)");
break;
case WASM_OPCODE_REF_NULL:
writeValueType(os, ValType::EXTERNREF, "literal (externref type)");
break;
default:
fatal("unknown opcode in init expr: " + Twine(initExpr.Opcode));
}
writeU8(os, WASM_OPCODE_END, "opcode:end");
}
void writeLimits(raw_ostream &os, const WasmLimits &limits) {
writeU8(os, limits.Flags, "limits flags");
writeUleb128(os, limits.Initial, "limits initial");
if (limits.Flags & WASM_LIMITS_FLAG_HAS_MAX)
writeUleb128(os, limits.Maximum, "limits max");
}
void writeGlobalType(raw_ostream &os, const WasmGlobalType &type) {
// TODO: Update WasmGlobalType to use ValType and remove this cast.
writeValueType(os, ValType(type.Type), "global type");
writeU8(os, type.Mutable, "global mutable");
}
void writeGlobal(raw_ostream &os, const WasmGlobal &global) {
writeGlobalType(os, global.Type);
writeInitExpr(os, global.InitExpr);
}
void writeEventType(raw_ostream &os, const WasmEventType &type) {
writeUleb128(os, type.Attribute, "event attribute");
writeUleb128(os, type.SigIndex, "sig index");
}
void writeEvent(raw_ostream &os, const WasmEvent &event) {
writeEventType(os, event.Type);
}
void writeTableType(raw_ostream &os, const llvm::wasm::WasmTable &type) {
writeU8(os, WASM_TYPE_FUNCREF, "table type");
writeLimits(os, type.Limits);
}
void writeImport(raw_ostream &os, const WasmImport &import) {
writeStr(os, import.Module, "import module name");
writeStr(os, import.Field, "import field name");
writeU8(os, import.Kind, "import kind");
switch (import.Kind) {
case WASM_EXTERNAL_FUNCTION:
writeUleb128(os, import.SigIndex, "import sig index");
break;
case WASM_EXTERNAL_GLOBAL:
writeGlobalType(os, import.Global);
break;
case WASM_EXTERNAL_EVENT:
writeEventType(os, import.Event);
break;
case WASM_EXTERNAL_MEMORY:
writeLimits(os, import.Memory);
break;
case WASM_EXTERNAL_TABLE:
writeTableType(os, import.Table);
break;
default:
fatal("unsupported import type: " + Twine(import.Kind));
}
}
void writeExport(raw_ostream &os, const WasmExport &export_) {
writeStr(os, export_.Name, "export name");
writeU8(os, export_.Kind, "export kind");
switch (export_.Kind) {
case WASM_EXTERNAL_FUNCTION:
writeUleb128(os, export_.Index, "function index");
break;
case WASM_EXTERNAL_GLOBAL:
writeUleb128(os, export_.Index, "global index");
break;
case WASM_EXTERNAL_EVENT:
writeUleb128(os, export_.Index, "event index");
break;
case WASM_EXTERNAL_MEMORY:
writeUleb128(os, export_.Index, "memory index");
break;
case WASM_EXTERNAL_TABLE:
writeUleb128(os, export_.Index, "table index");
break;
default:
fatal("unsupported export type: " + Twine(export_.Kind));
}
}
} // namespace wasm
} // namespace lld