xref: /llvm-project/clang/utils/TableGen/ClangOpcodesEmitter.cpp (revision 82ed9c0319c9f0373bcb633a03ce6d35ebac3661)
1 //===-- ClangOpcodesEmitter.cpp - constexpr interpreter opcodes -----------===//
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 // These tablegen backends emit Clang AST node tables
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "TableGenBackends.h"
14 #include "llvm/TableGen/Error.h"
15 #include "llvm/TableGen/Record.h"
16 #include "llvm/TableGen/StringMatcher.h"
17 #include "llvm/TableGen/TableGenBackend.h"
18 
19 using namespace llvm;
20 
21 namespace {
22 class ClangOpcodesEmitter {
23   const RecordKeeper &Records;
24   unsigned NumTypes;
25 
26 public:
27   ClangOpcodesEmitter(const RecordKeeper &R)
28       : Records(R), NumTypes(Records.getAllDerivedDefinitions("Type").size()) {}
29 
30   void run(raw_ostream &OS);
31 
32 private:
33   /// Emits the opcode name for the opcode enum.
34   /// The name is obtained by concatenating the name with the list of types.
35   void EmitEnum(raw_ostream &OS, StringRef N, const Record *R);
36 
37   /// Emits the switch case and the invocation in the interpreter.
38   void EmitInterp(raw_ostream &OS, StringRef N, const Record *R);
39 
40   /// Emits the disassembler.
41   void EmitDisasm(raw_ostream &OS, StringRef N, const Record *R);
42 
43   /// Emits the byte code emitter method.
44   void EmitEmitter(raw_ostream &OS, StringRef N, const Record *R);
45 
46   /// Emits the prototype.
47   void EmitProto(raw_ostream &OS, StringRef N, const Record *R);
48 
49   /// Emits the prototype to dispatch from a type.
50   void EmitGroup(raw_ostream &OS, StringRef N, const Record *R);
51 
52   /// Emits the evaluator method.
53   void EmitEval(raw_ostream &OS, StringRef N, const Record *R);
54 
55   void PrintTypes(raw_ostream &OS, ArrayRef<const Record *> Types);
56 };
57 
58 void Enumerate(const Record *R, StringRef N,
59                std::function<void(ArrayRef<const Record *>, Twine)> &&F) {
60   SmallVector<const Record *, 2> TypePath;
61   const auto *Types = R->getValueAsListInit("Types");
62 
63   std::function<void(size_t, const Twine &)> Rec;
64   Rec = [&TypePath, Types, &Rec, &F](size_t I, const Twine &ID) {
65     if (I >= Types->size()) {
66       F(TypePath, ID);
67       return;
68     }
69 
70     if (const auto *TypeClass = dyn_cast<DefInit>(Types->getElement(I))) {
71       for (const auto *Type :
72            TypeClass->getDef()->getValueAsListOfDefs("Types")) {
73         TypePath.push_back(Type);
74         Rec(I + 1, ID + Type->getName());
75         TypePath.pop_back();
76       }
77     } else {
78       PrintFatalError("Expected a type class");
79     }
80   };
81   Rec(0, N);
82 }
83 
84 } // namespace
85 
86 void ClangOpcodesEmitter::run(raw_ostream &OS) {
87   for (const auto *Opcode : Records.getAllDerivedDefinitions("Opcode")) {
88     // The name is the record name, unless overriden.
89     StringRef N = Opcode->getValueAsString("Name");
90     if (N.empty())
91       N = Opcode->getName();
92 
93     EmitEnum(OS, N, Opcode);
94     EmitInterp(OS, N, Opcode);
95     EmitDisasm(OS, N, Opcode);
96     EmitProto(OS, N, Opcode);
97     EmitGroup(OS, N, Opcode);
98     EmitEmitter(OS, N, Opcode);
99     EmitEval(OS, N, Opcode);
100   }
101 }
102 
103 void ClangOpcodesEmitter::EmitEnum(raw_ostream &OS, StringRef N,
104                                    const Record *R) {
105   OS << "#ifdef GET_OPCODE_NAMES\n";
106   Enumerate(R, N, [&OS](ArrayRef<const Record *>, const Twine &ID) {
107     OS << "OP_" << ID << ",\n";
108   });
109   OS << "#endif\n";
110 }
111 
112 void ClangOpcodesEmitter::EmitInterp(raw_ostream &OS, StringRef N,
113                                      const Record *R) {
114   OS << "#ifdef GET_INTERP\n";
115 
116   Enumerate(R, N,
117             [this, R, &OS, &N](ArrayRef<const Record *> TS, const Twine &ID) {
118               bool CanReturn = R->getValueAsBit("CanReturn");
119               bool ChangesPC = R->getValueAsBit("ChangesPC");
120               const auto &Args = R->getValueAsListOfDefs("Args");
121 
122               OS << "case OP_" << ID << ": {\n";
123 
124               if (CanReturn)
125                 OS << "  bool DoReturn = (S.Current == StartFrame);\n";
126 
127               // Emit calls to read arguments.
128               for (size_t I = 0, N = Args.size(); I < N; ++I) {
129                 const auto *Arg = Args[I];
130                 bool AsRef = Arg->getValueAsBit("AsRef");
131 
132                 if (AsRef)
133                   OS << "  const auto &V" << I;
134                 else
135                   OS << "  const auto V" << I;
136                 OS << " = ";
137                 OS << "ReadArg<" << Arg->getValueAsString("Name")
138                    << ">(S, PC);\n";
139               }
140 
141               // Emit a call to the template method and pass arguments.
142               OS << "  if (!" << N;
143               PrintTypes(OS, TS);
144               OS << "(S";
145               if (ChangesPC)
146                 OS << ", PC";
147               else
148                 OS << ", OpPC";
149               for (size_t I = 0, N = Args.size(); I < N; ++I)
150                 OS << ", V" << I;
151               OS << "))\n";
152               OS << "    return false;\n";
153 
154               // Bail out if interpreter returned.
155               if (CanReturn) {
156                 OS << "  if (!S.Current || S.Current->isRoot())\n";
157                 OS << "    return true;\n";
158 
159                 OS << "  if (DoReturn)\n";
160                 OS << "    return true;\n";
161               }
162 
163               OS << "  continue;\n";
164               OS << "}\n";
165             });
166   OS << "#endif\n";
167 }
168 
169 void ClangOpcodesEmitter::EmitDisasm(raw_ostream &OS, StringRef N,
170                                      const Record *R) {
171   OS << "#ifdef GET_DISASM\n";
172   Enumerate(R, N, [R, &OS](ArrayRef<const Record *>, const Twine &ID) {
173     OS << "case OP_" << ID << ":\n";
174     OS << "  PrintName(\"" << ID << "\");\n";
175     OS << "  OS << \"\\t\"";
176 
177     for (const auto *Arg : R->getValueAsListOfDefs("Args")) {
178       OS << " << ReadArg<" << Arg->getValueAsString("Name") << ">(P, PC)";
179       OS << " << \" \"";
180     }
181 
182     OS << " << \"\\n\";\n";
183     OS << "  continue;\n";
184   });
185   OS << "#endif\n";
186 }
187 
188 void ClangOpcodesEmitter::EmitEmitter(raw_ostream &OS, StringRef N,
189                                       const Record *R) {
190   if (R->getValueAsBit("HasCustomLink"))
191     return;
192 
193   OS << "#ifdef GET_LINK_IMPL\n";
194   Enumerate(R, N, [R, &OS](ArrayRef<const Record *>, const Twine &ID) {
195     const auto &Args = R->getValueAsListOfDefs("Args");
196 
197     // Emit the list of arguments.
198     OS << "bool ByteCodeEmitter::emit" << ID << "(";
199     for (size_t I = 0, N = Args.size(); I < N; ++I) {
200       const auto *Arg = Args[I];
201       bool AsRef = Arg->getValueAsBit("AsRef");
202       auto Name = Arg->getValueAsString("Name");
203 
204       OS << (AsRef ? "const " : " ") << Name << " " << (AsRef ? "&" : "") << "A"
205          << I << ", ";
206     }
207     OS << "const SourceInfo &L) {\n";
208 
209     // Emit a call to write the opcodes.
210     OS << "  return emitOp<";
211     for (size_t I = 0, N = Args.size(); I < N; ++I) {
212       if (I != 0)
213         OS << ", ";
214       OS << Args[I]->getValueAsString("Name");
215     }
216     OS << ">(OP_" << ID;
217     for (size_t I = 0, N = Args.size(); I < N; ++I)
218       OS << ", A" << I;
219     OS << ", L);\n";
220     OS << "}\n";
221   });
222   OS << "#endif\n";
223 }
224 
225 void ClangOpcodesEmitter::EmitProto(raw_ostream &OS, StringRef N,
226                                     const Record *R) {
227   OS << "#if defined(GET_EVAL_PROTO) || defined(GET_LINK_PROTO)\n";
228   auto Args = R->getValueAsListOfDefs("Args");
229   Enumerate(R, N, [&OS, &Args](ArrayRef<const Record *> TS, const Twine &ID) {
230     OS << "bool emit" << ID << "(";
231     for (size_t I = 0, N = Args.size(); I < N; ++I) {
232       const auto *Arg = Args[I];
233       bool AsRef = Arg->getValueAsBit("AsRef");
234       auto Name = Arg->getValueAsString("Name");
235 
236       OS << (AsRef ? "const " : " ") << Name << " " << (AsRef ? "&" : "")
237          << ", ";
238     }
239     OS << "const SourceInfo &);\n";
240   });
241 
242   // Emit a template method for custom emitters to have less to implement.
243   auto TypeCount = R->getValueAsListInit("Types")->size();
244   if (R->getValueAsBit("HasCustomEval") && TypeCount) {
245     OS << "#if defined(GET_EVAL_PROTO)\n";
246     OS << "template<";
247     for (size_t I = 0; I < TypeCount; ++I) {
248       if (I != 0)
249         OS << ", ";
250       OS << "PrimType";
251     }
252     OS << ">\n";
253     OS << "bool emit" << N << "(";
254     for (const auto *Arg : Args)
255       OS << Arg->getValueAsString("Name") << ", ";
256     OS << "const SourceInfo &);\n";
257     OS << "#endif\n";
258   }
259 
260   OS << "#endif\n";
261 }
262 
263 void ClangOpcodesEmitter::EmitGroup(raw_ostream &OS, StringRef N,
264                                     const Record *R) {
265   if (!R->getValueAsBit("HasGroup"))
266     return;
267 
268   const auto *Types = R->getValueAsListInit("Types");
269   const auto &Args = R->getValueAsListOfDefs("Args");
270 
271   Twine EmitFuncName = "emit" + N;
272 
273   // Emit the prototype of the group emitter in the header.
274   OS << "#if defined(GET_EVAL_PROTO) || defined(GET_LINK_PROTO)\n";
275   OS << "[[nodiscard]] bool " << EmitFuncName << "(";
276   for (size_t I = 0, N = Types->size(); I < N; ++I)
277     OS << "PrimType, ";
278   for (auto *Arg : Args)
279     OS << Arg->getValueAsString("Name") << ", ";
280   OS << "const SourceInfo &I);\n";
281   OS << "#endif\n";
282 
283   // Emit the dispatch implementation in the source.
284   OS << "#if defined(GET_EVAL_IMPL) || defined(GET_LINK_IMPL)\n";
285   OS << "bool\n";
286   OS << "#if defined(GET_EVAL_IMPL)\n";
287   OS << "EvalEmitter\n";
288   OS << "#else\n";
289   OS << "ByteCodeEmitter\n";
290   OS << "#endif\n";
291   OS << "::" << EmitFuncName << "(";
292   for (size_t I = 0, N = Types->size(); I < N; ++I)
293     OS << "PrimType T" << I << ", ";
294   for (size_t I = 0, N = Args.size(); I < N; ++I) {
295     const auto *Arg = Args[I];
296     bool AsRef = Arg->getValueAsBit("AsRef");
297     auto Name = Arg->getValueAsString("Name");
298 
299     OS << (AsRef ? "const " : " ") << Name << " " << (AsRef ? "&" : "") << "A"
300        << I << ", ";
301   }
302   OS << "const SourceInfo &I) {\n";
303 
304   std::function<void(size_t, const Twine &)> Rec;
305   SmallVector<const Record *, 2> TS;
306   Rec = [this, &Rec, &OS, Types, &Args, R, &TS, N,
307          EmitFuncName](size_t I, const Twine &ID) {
308     if (I >= Types->size()) {
309       // Print a call to the emitter method.
310       // Custom evaluator methods dispatch to template methods.
311       if (R->getValueAsBit("HasCustomEval")) {
312         OS << "#ifdef GET_LINK_IMPL\n";
313         OS << "    return emit" << ID << "\n";
314         OS << "#else\n";
315         OS << "    return emit" << N;
316         PrintTypes(OS, TS);
317         OS << "\n#endif\n";
318         OS << "      ";
319       } else {
320         OS << "    return emit" << ID;
321       }
322 
323       OS << "(";
324       for (size_t I = 0; I < Args.size(); ++I) {
325         OS << "A" << I << ", ";
326       }
327       OS << "I);\n";
328       return;
329     }
330 
331     // Print a switch statement selecting T.
332     if (auto *TypeClass = dyn_cast<DefInit>(Types->getElement(I))) {
333       OS << "  switch (T" << I << ") {\n";
334       auto Cases = TypeClass->getDef()->getValueAsListOfDefs("Types");
335       for (auto *Case : Cases) {
336         OS << "  case PT_" << Case->getName() << ":\n";
337         TS.push_back(Case);
338         Rec(I + 1, ID + Case->getName());
339         TS.pop_back();
340       }
341       // Emit a default case if not all types are present.
342       if (Cases.size() < NumTypes)
343         OS << "  default: llvm_unreachable(\"invalid type: " << EmitFuncName
344            << "\");\n";
345       OS << "  }\n";
346       OS << "  llvm_unreachable(\"invalid enum value\");\n";
347     } else {
348       PrintFatalError("Expected a type class");
349     }
350   };
351   Rec(0, N);
352 
353   OS << "}\n";
354   OS << "#endif\n";
355 }
356 
357 void ClangOpcodesEmitter::EmitEval(raw_ostream &OS, StringRef N,
358                                    const Record *R) {
359   if (R->getValueAsBit("HasCustomEval"))
360     return;
361 
362   OS << "#ifdef GET_EVAL_IMPL\n";
363   Enumerate(R, N,
364             [this, R, &N, &OS](ArrayRef<const Record *> TS, const Twine &ID) {
365               auto Args = R->getValueAsListOfDefs("Args");
366 
367               OS << "bool EvalEmitter::emit" << ID << "(";
368               for (size_t I = 0, N = Args.size(); I < N; ++I) {
369                 const auto *Arg = Args[I];
370                 bool AsRef = Arg->getValueAsBit("AsRef");
371                 auto Name = Arg->getValueAsString("Name");
372 
373                 OS << (AsRef ? "const " : " ") << Name << " "
374                    << (AsRef ? "&" : "") << "A" << I << ", ";
375               }
376               OS << "const SourceInfo &L) {\n";
377               OS << "  if (!isActive()) return true;\n";
378               OS << "  CurrentSource = L;\n";
379 
380               OS << "  return " << N;
381               PrintTypes(OS, TS);
382               OS << "(S, OpPC";
383               for (size_t I = 0, N = Args.size(); I < N; ++I)
384                 OS << ", A" << I;
385               OS << ");\n";
386               OS << "}\n";
387             });
388 
389   OS << "#endif\n";
390 }
391 
392 void ClangOpcodesEmitter::PrintTypes(raw_ostream &OS,
393                                      ArrayRef<const Record *> Types) {
394   if (Types.empty())
395     return;
396   OS << "<";
397   for (size_t I = 0, N = Types.size(); I < N; ++I) {
398     if (I != 0)
399       OS << ", ";
400     OS << "PT_" << Types[I]->getName();
401   }
402   OS << ">";
403 }
404 
405 void clang::EmitClangOpcodes(const RecordKeeper &Records, raw_ostream &OS) {
406   ClangOpcodesEmitter(Records).run(OS);
407 }
408