mlir/tools/mlir-tblgen/BytecodeDialectGen.cpp

   1 //===- BytecodeDialectGen.cpp - Dialect bytecode read/writer gen  ---------===//
   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 "mlir/Support/IndentedOstream.h"
  10 #include "mlir/TableGen/GenInfo.h"
  11 #include "llvm/ADT/MapVector.h"
  12 #include "llvm/ADT/STLExtras.h"
  13 #include "llvm/Support/CommandLine.h"
  14 #include "llvm/Support/FormatVariadic.h"
  15 #include "llvm/TableGen/Error.h"
  16 #include "llvm/TableGen/Record.h"
  17 #include <regex>
  18
  19 using namespace llvm;
  20
  21 static llvm::cl::OptionCategory dialectGenCat("Options for -gen-bytecode");
  22 static llvm::cl::opt<std::string>
  23     selectedBcDialect("bytecode-dialect",
  24                       llvm::cl::desc("The dialect to gen for"),
  25                       llvm::cl::cat(dialectGenCat), llvm::cl::CommaSeparated);
  26
  27 namespace {
  28
  29 /// Helper class to generate C++ bytecode parser helpers.
  30 class Generator {
  31 public:
  32   Generator(raw_ostream &output) : output(output) {}
  33
  34   /// Returns whether successfully emitted attribute/type parsers.
  35   void emitParse(StringRef kind, Record &x);
  36
  37   /// Returns whether successfully emitted attribute/type printers.
  38   void emitPrint(StringRef kind, StringRef type,
  39                  ArrayRef<std::pair<int64_t, Record *>> vec);
  40
  41   /// Emits parse dispatch table.
  42   void emitParseDispatch(StringRef kind, ArrayRef<Record *> vec);
  43
  44   /// Emits print dispatch table.
  45   void emitPrintDispatch(StringRef kind, ArrayRef<std::string> vec);
  46
  47 private:
  48   /// Emits parse calls to construct given kind.
  49   void emitParseHelper(StringRef kind, StringRef returnType, StringRef builder,
  50                        ArrayRef<Init *> args, ArrayRef<std::string> argNames,
  51                        StringRef failure, mlir::raw_indented_ostream &ios);
  52
  53   /// Emits print instructions.
  54   void emitPrintHelper(Record *memberRec, StringRef kind, StringRef parent,
  55                        StringRef name, mlir::raw_indented_ostream &ios);
  56
  57   raw_ostream &output;
  58 };
  59 } // namespace
  60
  61 /// Helper to replace set of from strings to target in `s`.
  62 /// Assumed: non-overlapping replacements.
  63 static std::string format(StringRef templ,
  64                           std::map<std::string, std::string> &&map) {
  65   std::string s = templ.str();
  66   for (const auto &[from, to] : map)
  67     // All replacements start with $, don't treat as anchor.
  68     s = std::regex_replace(s, std::regex("\\" + from), to);
  69   return s;
  70 }
  71
  72 /// Return string with first character capitalized.
  73 static std::string capitalize(StringRef str) {
  74   return ((Twine)toUpper(str[0]) + str.drop_front()).str();
  75 }
  76
  77 /// Return the C++ type for the given record.
  78 static std::string getCType(Record *def) {
  79   std::string format = "{0}";
  80   if (def->isSubClassOf("Array")) {
  81     def = def->getValueAsDef("elemT");
  82     format = "SmallVector<{0}>";
  83   }
  84
  85   StringRef cType = def->getValueAsString("cType");
  86   if (cType.empty()) {
  87     if (def->isAnonymous())
  88       PrintFatalError(def->getLoc(), "Unable to determine cType");
  89
  90     return formatv(format.c_str(), def->getName().str());
  91   }
  92   return formatv(format.c_str(), cType.str());
  93 }
  94
  95 void Generator::emitParseDispatch(StringRef kind, ArrayRef<Record *> vec) {
  96   mlir::raw_indented_ostream os(output);
  97   char const *head =
  98       R"(static {0} read{0}(MLIRContext* context, DialectBytecodeReader &reader))";
  99   os << formatv(head, capitalize(kind));
 100   auto funScope = os.scope(" {\n", "}\n\n");
 101
 102   os << "uint64_t kind;\n";
 103   os << "if (failed(reader.readVarInt(kind)))\n"
 104      << "  return " << capitalize(kind) << "();\n";
 105   os << "switch (kind) ";
 106   {
 107     auto switchScope = os.scope("{\n", "}\n");
 108     for (const auto &it : llvm::enumerate(vec)) {
 109       os << formatv("case {1}:\n  return read{0}(context, reader);\n",
 110                     it.value()->getName(), it.index());
 111     }
 112     os << "default:\n"
 113        << "  reader.emitError() << \"unknown attribute code: \" "
 114        << "<< kind;\n"
 115        << "  return " << capitalize(kind) << "();\n";
 116   }
 117   os << "return " << capitalize(kind) << "();\n";
 118 }
 119
 120 void Generator::emitParse(StringRef kind, Record &x) {
 121   char const *head =
 122       R"(static {0} read{1}(MLIRContext* context, DialectBytecodeReader &reader) )";
 123   mlir::raw_indented_ostream os(output);
 124   std::string returnType = getCType(&x);
 125   os << formatv(head, returnType, x.getName());
 126   DagInit *members = x.getValueAsDag("members");
 127   SmallVector<std::string> argNames =
 128       llvm::to_vector(map_range(members->getArgNames(), [](StringInit *init) {
 129         return init->getAsUnquotedString();
 130       }));
 131   StringRef builder = x.getValueAsString("cBuilder");
 132   emitParseHelper(kind, returnType, builder, members->getArgs(), argNames,
 133                   returnType + "()", os);
 134   os << "\n\n";
 135 }
 136
 137 void printParseConditional(mlir::raw_indented_ostream &ios,
 138                            ArrayRef<Init *> args,
 139                            ArrayRef<std::string> argNames) {
 140   ios << "if ";
 141   auto parenScope = ios.scope("(", ") {");
 142   ios.indent();
 143
 144   auto listHelperName = [](StringRef name) {
 145     return formatv("read{0}", capitalize(name));
 146   };
 147
 148   auto parsedArgs =
 149       llvm::to_vector(make_filter_range(args, [](Init *const attr) {
 150         Record *def = cast<DefInit>(attr)->getDef();
 151         if (def->isSubClassOf("Array"))
 152           return true;
 153         return !def->getValueAsString("cParser").empty();
 154       }));
 155
 156   interleave(
 157       zip(parsedArgs, argNames),
 158       [&](std::tuple<llvm::Init *&, const std::string &> it) {
 159         Record *attr = cast<DefInit>(std::get<0>(it))->getDef();
 160         std::string parser;
 161         if (auto optParser = attr->getValueAsOptionalString("cParser")) {
 162           parser = *optParser;
 163         } else if (attr->isSubClassOf("Array")) {
 164           Record *def = attr->getValueAsDef("elemT");
 165           bool composite = def->isSubClassOf("CompositeBytecode");
 166           if (!composite && def->isSubClassOf("AttributeKind"))
 167             parser = "succeeded($_reader.readAttributes($_var))";
 168           else if (!composite && def->isSubClassOf("TypeKind"))
 169             parser = "succeeded($_reader.readTypes($_var))";
 170           else
 171             parser = ("succeeded($_reader.readList($_var, " +
 172                       listHelperName(std::get<1>(it)) + "))")
 173                          .str();
 174         } else {
 175           PrintFatalError(attr->getLoc(), "No parser specified");
 176         }
 177         std::string type = getCType(attr);
 178         ios << format(parser, {{"$_reader", "reader"},
 179                                {"$_resultType", type},
 180                                {"$_var", std::get<1>(it)}});
 181       },
 182       [&]() { ios << " &&\n"; });
 183 }
 184
 185 void Generator::emitParseHelper(StringRef kind, StringRef returnType,
 186                                 StringRef builder, ArrayRef<Init *> args,
 187                                 ArrayRef<std::string> argNames,
 188                                 StringRef failure,
 189                                 mlir::raw_indented_ostream &ios) {
 190   auto funScope = ios.scope("{\n", "}");
 191
 192   if (args.empty()) {
 193     ios << formatv("return get<{0}>(context);\n", returnType);
 194     return;
 195   }
 196
 197   // Print decls.
 198   std::string lastCType = "";
 199   for (auto [arg, name] : zip(args, argNames)) {
 200     DefInit *first = dyn_cast<DefInit>(arg);
 201     if (!first)
 202       PrintFatalError("Unexpected type for " + name);
 203     Record *def = first->getDef();
 204
 205     // Create variable decls, if there are a block of same type then create
 206     // comma separated list of them.
 207     std::string cType = getCType(def);
 208     if (lastCType == cType) {
 209       ios << ", ";
 210     } else {
 211       if (!lastCType.empty())
 212         ios << ";\n";
 213       ios << cType << " ";
 214     }
 215     ios << name;
 216     lastCType = cType;
 217   }
 218   ios << ";\n";
 219
 220   // Returns the name of the helper used in list parsing. E.g., the name of the
 221   // lambda passed to array parsing.
 222   auto listHelperName = [](StringRef name) {
 223     return formatv("read{0}", capitalize(name));
 224   };
 225
 226   // Emit list helper functions.
 227   for (auto [arg, name] : zip(args, argNames)) {
 228     Record *attr = cast<DefInit>(arg)->getDef();
 229     if (!attr->isSubClassOf("Array"))
 230       continue;
 231
 232     // TODO: Dedupe readers.
 233     Record *def = attr->getValueAsDef("elemT");
 234     if (!def->isSubClassOf("CompositeBytecode") &&
 235         (def->isSubClassOf("AttributeKind") || def->isSubClassOf("TypeKind")))
 236       continue;
 237
 238     std::string returnType = getCType(def);
 239     ios << "auto " << listHelperName(name) << " = [&]() -> FailureOr<"
 240         << returnType << "> ";
 241     SmallVector<Init *> args;
 242     SmallVector<std::string> argNames;
 243     if (def->isSubClassOf("CompositeBytecode")) {
 244       DagInit *members = def->getValueAsDag("members");
 245       args = llvm::to_vector(members->getArgs());
 246       argNames = llvm::to_vector(
 247           map_range(members->getArgNames(), [](StringInit *init) {
 248             return init->getAsUnquotedString();
 249           }));
 250     } else {
 251       args = {def->getDefInit()};
 252       argNames = {"temp"};
 253     }
 254     StringRef builder = def->getValueAsString("cBuilder");
 255     emitParseHelper(kind, returnType, builder, args, argNames, "failure()",
 256                     ios);
 257     ios << ";\n";
 258   }
 259
 260   // Print parse conditional.
 261   printParseConditional(ios, args, argNames);
 262
 263   // Compute args to pass to create method.
 264   auto passedArgs = llvm::to_vector(make_filter_range(
 265       argNames, [](StringRef str) { return !str.starts_with("_"); }));
 266   std::string argStr;
 267   raw_string_ostream argStream(argStr);
 268   interleaveComma(passedArgs, argStream,
 269                   [&](const std::string &str) { argStream << str; });
 270   // Return the invoked constructor.
 271   ios << "\nreturn "
 272       << format(builder, {{"$_resultType", returnType.str()},
 273                           {"$_args", argStream.str()}})
 274       << ";\n";
 275   ios.unindent();
 276
 277   // TODO: Emit error in debug.
 278   // This assumes the result types in error case can always be empty
 279   // constructed.
 280   ios << "}\nreturn " << failure << ";\n";
 281 }
 282
 283 void Generator::emitPrint(StringRef kind, StringRef type,
 284                           ArrayRef<std::pair<int64_t, Record *>> vec) {
 285   char const *head =
 286       R"(static void write({0} {1}, DialectBytecodeWriter &writer) )";
 287   mlir::raw_indented_ostream os(output);
 288   os << formatv(head, type, kind);
 289   auto funScope = os.scope("{\n", "}\n\n");
 290
 291   // Check that predicates specified if multiple bytecode instances.
 292   for (llvm::Record *rec : make_second_range(vec)) {
 293     StringRef pred = rec->getValueAsString("printerPredicate");
 294     if (vec.size() > 1 && pred.empty()) {
 295       for (auto [index, rec] : vec) {
 296         (void)index;
 297         StringRef pred = rec->getValueAsString("printerPredicate");
 298         if (vec.size() > 1 && pred.empty())
 299           PrintError(rec->getLoc(),
 300                      "Requires parsing predicate given common cType");
 301       }
 302       PrintFatalError("Unspecified for shared cType " + type);
 303     }
 304   }
 305
 306   for (auto [index, rec] : vec) {
 307     StringRef pred = rec->getValueAsString("printerPredicate");
 308     if (!pred.empty()) {
 309       os << "if (" << format(pred, {{"$_val", kind.str()}}) << ") {\n";
 310       os.indent();
 311     }
 312
 313     os << "writer.writeVarInt(/* " << rec->getName() << " */ " << index
 314        << ");\n";
 315
 316     auto *members = rec->getValueAsDag("members");
 317     for (auto [arg, name] :
 318          llvm::zip(members->getArgs(), members->getArgNames())) {
 319       DefInit *def = dyn_cast<DefInit>(arg);
 320       assert(def);
 321       Record *memberRec = def->getDef();
 322       emitPrintHelper(memberRec, kind, kind, name->getAsUnquotedString(), os);
 323     }
 324
 325     if (!pred.empty()) {
 326       os.unindent();
 327       os << "}\n";
 328     }
 329   }
 330 }
 331
 332 void Generator::emitPrintHelper(Record *memberRec, StringRef kind,
 333                                 StringRef parent, StringRef name,
 334                                 mlir::raw_indented_ostream &ios) {
 335   std::string getter;
 336   if (auto cGetter = memberRec->getValueAsOptionalString("cGetter");
 337       cGetter && !cGetter->empty()) {
 338     getter = format(
 339         *cGetter,
 340         {{"$_attrType", parent.str()},
 341          {"$_member", name.str()},
 342          {"$_getMember", "get" + convertToCamelFromSnakeCase(name, true)}});
 343   } else {
 344     getter =
 345         formatv("{0}.get{1}()", parent, convertToCamelFromSnakeCase(name, true))
 346             .str();
 347   }
 348
 349   if (memberRec->isSubClassOf("Array")) {
 350     Record *def = memberRec->getValueAsDef("elemT");
 351     if (!def->isSubClassOf("CompositeBytecode")) {
 352       if (def->isSubClassOf("AttributeKind")) {
 353         ios << "writer.writeAttributes(" << getter << ");\n";
 354         return;
 355       }
 356       if (def->isSubClassOf("TypeKind")) {
 357         ios << "writer.writeTypes(" << getter << ");\n";
 358         return;
 359       }
 360     }
 361     std::string returnType = getCType(def);
 362     ios << "writer.writeList(" << getter << ", [&](" << returnType << " "
 363         << kind << ") ";
 364     auto lambdaScope = ios.scope("{\n", "});\n");
 365     return emitPrintHelper(def, kind, kind, kind, ios);
 366   }
 367   if (memberRec->isSubClassOf("CompositeBytecode")) {
 368     auto *members = memberRec->getValueAsDag("members");
 369     for (auto [arg, argName] :
 370          zip(members->getArgs(), members->getArgNames())) {
 371       DefInit *def = dyn_cast<DefInit>(arg);
 372       assert(def);
 373       emitPrintHelper(def->getDef(), kind, parent,
 374                       argName->getAsUnquotedString(), ios);
 375     }
 376   }
 377
 378   if (std::string printer = memberRec->getValueAsString("cPrinter").str();
 379       !printer.empty())
 380     ios << format(printer, {{"$_writer", "writer"},
 381                             {"$_name", kind.str()},
 382                             {"$_getter", getter}})
 383         << ";\n";
 384 }
 385
 386 void Generator::emitPrintDispatch(StringRef kind, ArrayRef<std::string> vec) {
 387   mlir::raw_indented_ostream os(output);
 388   char const *head = R"(static LogicalResult write{0}({0} {1},
 389                                 DialectBytecodeWriter &writer))";
 390   os << formatv(head, capitalize(kind), kind);
 391   auto funScope = os.scope(" {\n", "}\n\n");
 392
 393   os << "return TypeSwitch<" << capitalize(kind) << ", LogicalResult>(" << kind
 394      << ")";
 395   auto switchScope = os.scope("", "");
 396   for (StringRef type : vec) {
 397     os << "\n.Case([&](" << type << " t)";
 398     auto caseScope = os.scope(" {\n", "})");
 399     os << "return write(t, writer), success();\n";
 400   }
 401   os << "\n.Default([&](" << capitalize(kind) << ") { return failure(); });\n";
 402 }
 403
 404 namespace {
 405 /// Container of Attribute or Type for Dialect.
 406 struct AttrOrType {
 407   std::vector<Record *> attr, type;
 408 };
 409 } // namespace
 410
 411 static bool emitBCRW(const RecordKeeper &records, raw_ostream &os) {
 412   MapVector<StringRef, AttrOrType> dialectAttrOrType;
 413   for (auto &it : records.getAllDerivedDefinitions("DialectAttributes")) {
 414     if (!selectedBcDialect.empty() &&
 415         it->getValueAsString("dialect") != selectedBcDialect)
 416       continue;
 417     dialectAttrOrType[it->getValueAsString("dialect")].attr =
 418         it->getValueAsListOfDefs("elems");
 419   }
 420   for (auto &it : records.getAllDerivedDefinitions("DialectTypes")) {
 421     if (!selectedBcDialect.empty() &&
 422         it->getValueAsString("dialect") != selectedBcDialect)
 423       continue;
 424     dialectAttrOrType[it->getValueAsString("dialect")].type =
 425         it->getValueAsListOfDefs("elems");
 426   }
 427
 428   if (dialectAttrOrType.size() != 1)
 429     PrintFatalError("Single dialect per invocation required (either only "
 430                     "one in input file or specified via dialect option)");
 431
 432   auto it = dialectAttrOrType.front();
 433   Generator gen(os);
 434
 435   SmallVector<std::vector<Record *> *, 2> vecs;
 436   SmallVector<std::string, 2> kinds;
 437   vecs.push_back(&it.second.attr);
 438   kinds.push_back("attribute");
 439   vecs.push_back(&it.second.type);
 440   kinds.push_back("type");
 441   for (auto [vec, kind] : zip(vecs, kinds)) {
 442     // Handle Attribute/Type emission.
 443     std::map<std::string, std::vector<std::pair<int64_t, Record *>>> perType;
 444     for (auto kt : llvm::enumerate(*vec))
 445       perType[getCType(kt.value())].emplace_back(kt.index(), kt.value());
 446     for (const auto &jt : perType) {
 447       for (auto kt : jt.second)
 448         gen.emitParse(kind, *std::get<1>(kt));
 449       gen.emitPrint(kind, jt.first, jt.second);
 450     }
 451     gen.emitParseDispatch(kind, *vec);
 452
 453     SmallVector<std::string> types;
 454     for (const auto &it : perType) {
 455       types.push_back(it.first);
 456     }
 457     gen.emitPrintDispatch(kind, types);
 458   }
 459
 460   return false;
 461 }
 462
 463 static mlir::GenRegistration
 464     genBCRW("gen-bytecode", "Generate dialect bytecode readers/writers",
 465             [](const RecordKeeper &records, raw_ostream &os) {
 466               return emitBCRW(records, os);
 467             });