lib/Demangle/ItaniumDemangle.cpp

   1 //===------------------------- ItaniumDemangle.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 // FIXME: (possibly) incomplete list of features that clang mangles that this
  10 // file does not yet support:
  11 //   - C++ modules TS
  12
  13 #include "llvm/Demangle/Demangle.h"
  14 #include "llvm/Demangle/ItaniumDemangle.h"
  15
  16 #include <cassert>
  17 #include <cctype>
  18 #include <cstdio>
  19 #include <cstdlib>
  20 #include <cstring>
  21 #include <functional>
  22 #include <numeric>
  23 #include <utility>
  24 #include <vector>
  25
  26 using namespace llvm;
  27 using namespace llvm::itanium_demangle;
  28
  29 constexpr const char *itanium_demangle::FloatData<float>::spec;
  30 constexpr const char *itanium_demangle::FloatData<double>::spec;
  31 constexpr const char *itanium_demangle::FloatData<long double>::spec;
  32
  33 // <discriminator> := _ <non-negative number>      # when number < 10
  34 //                 := __ <non-negative number> _   # when number >= 10
  35 //  extension      := decimal-digit+               # at the end of string
  36 const char *itanium_demangle::parse_discriminator(const char *first,
  37                                                   const char *last) {
  38   // parse but ignore discriminator
  39   if (first != last) {
  40     if (*first == '_') {
  41       const char *t1 = first + 1;
  42       if (t1 != last) {
  43         if (std::isdigit(*t1))
  44           first = t1 + 1;
  45         else if (*t1 == '_') {
  46           for (++t1; t1 != last && std::isdigit(*t1); ++t1)
  47             ;
  48           if (t1 != last && *t1 == '_')
  49             first = t1 + 1;
  50         }
  51       }
  52     } else if (std::isdigit(*first)) {
  53       const char *t1 = first + 1;
  54       for (; t1 != last && std::isdigit(*t1); ++t1)
  55         ;
  56       if (t1 == last)
  57         first = last;
  58     }
  59   }
  60   return first;
  61 }
  62
  63 #ifndef NDEBUG
  64 namespace {
  65 struct DumpVisitor {
  66   unsigned Depth = 0;
  67   bool PendingNewline = false;
  68
  69   template<typename NodeT> static constexpr bool wantsNewline(const NodeT *) {
  70     return true;
  71   }
  72   static bool wantsNewline(NodeArray A) { return !A.empty(); }
  73   static constexpr bool wantsNewline(...) { return false; }
  74
  75   template<typename ...Ts> static bool anyWantNewline(Ts ...Vs) {
  76     for (bool B : {wantsNewline(Vs)...})
  77       if (B)
  78         return true;
  79     return false;
  80   }
  81
  82   void printStr(const char *S) { fprintf(stderr, "%s", S); }
  83   void print(StringView SV) {
  84     fprintf(stderr, "\"%.*s\"", (int)SV.size(), SV.begin());
  85   }
  86   void print(const Node *N) {
  87     if (N)
  88       N->visit(std::ref(*this));
  89     else
  90       printStr("<null>");
  91   }
  92   void print(NodeOrString NS) {
  93     if (NS.isNode())
  94       print(NS.asNode());
  95     else if (NS.isString())
  96       print(NS.asString());
  97     else
  98       printStr("NodeOrString()");
  99   }
 100   void print(NodeArray A) {
 101     ++Depth;
 102     printStr("{");
 103     bool First = true;
 104     for (const Node *N : A) {
 105       if (First)
 106         print(N);
 107       else
 108         printWithComma(N);
 109       First = false;
 110     }
 111     printStr("}");
 112     --Depth;
 113   }
 114
 115   // Overload used when T is exactly 'bool', not merely convertible to 'bool'.
 116   void print(bool B) { printStr(B ? "true" : "false"); }
 117
 118   template <class T>
 119   typename std::enable_if<std::is_unsigned<T>::value>::type print(T N) {
 120     fprintf(stderr, "%llu", (unsigned long long)N);
 121   }
 122
 123   template <class T>
 124   typename std::enable_if<std::is_signed<T>::value>::type print(T N) {
 125     fprintf(stderr, "%lld", (long long)N);
 126   }
 127
 128   void print(ReferenceKind RK) {
 129     switch (RK) {
 130     case ReferenceKind::LValue:
 131       return printStr("ReferenceKind::LValue");
 132     case ReferenceKind::RValue:
 133       return printStr("ReferenceKind::RValue");
 134     }
 135   }
 136   void print(FunctionRefQual RQ) {
 137     switch (RQ) {
 138     case FunctionRefQual::FrefQualNone:
 139       return printStr("FunctionRefQual::FrefQualNone");
 140     case FunctionRefQual::FrefQualLValue:
 141       return printStr("FunctionRefQual::FrefQualLValue");
 142     case FunctionRefQual::FrefQualRValue:
 143       return printStr("FunctionRefQual::FrefQualRValue");
 144     }
 145   }
 146   void print(Qualifiers Qs) {
 147     if (!Qs) return printStr("QualNone");
 148     struct QualName { Qualifiers Q; const char *Name; } Names[] = {
 149       {QualConst, "QualConst"},
 150       {QualVolatile, "QualVolatile"},
 151       {QualRestrict, "QualRestrict"},
 152     };
 153     for (QualName Name : Names) {
 154       if (Qs & Name.Q) {
 155         printStr(Name.Name);
 156         Qs = Qualifiers(Qs & ~Name.Q);
 157         if (Qs) printStr(" | ");
 158       }
 159     }
 160   }
 161   void print(SpecialSubKind SSK) {
 162     switch (SSK) {
 163     case SpecialSubKind::allocator:
 164       return printStr("SpecialSubKind::allocator");
 165     case SpecialSubKind::basic_string:
 166       return printStr("SpecialSubKind::basic_string");
 167     case SpecialSubKind::string:
 168       return printStr("SpecialSubKind::string");
 169     case SpecialSubKind::istream:
 170       return printStr("SpecialSubKind::istream");
 171     case SpecialSubKind::ostream:
 172       return printStr("SpecialSubKind::ostream");
 173     case SpecialSubKind::iostream:
 174       return printStr("SpecialSubKind::iostream");
 175     }
 176   }
 177
 178   void newLine() {
 179     printStr("\n");
 180     for (unsigned I = 0; I != Depth; ++I)
 181       printStr(" ");
 182     PendingNewline = false;
 183   }
 184
 185   template<typename T> void printWithPendingNewline(T V) {
 186     print(V);
 187     if (wantsNewline(V))
 188       PendingNewline = true;
 189   }
 190
 191   template<typename T> void printWithComma(T V) {
 192     if (PendingNewline || wantsNewline(V)) {
 193       printStr(",");
 194       newLine();
 195     } else {
 196       printStr(", ");
 197     }
 198
 199     printWithPendingNewline(V);
 200   }
 201
 202   struct CtorArgPrinter {
 203     DumpVisitor &Visitor;
 204
 205     template<typename T, typename ...Rest> void operator()(T V, Rest ...Vs) {
 206       if (Visitor.anyWantNewline(V, Vs...))
 207         Visitor.newLine();
 208       Visitor.printWithPendingNewline(V);
 209       int PrintInOrder[] = { (Visitor.printWithComma(Vs), 0)..., 0 };
 210       (void)PrintInOrder;
 211     }
 212   };
 213
 214   template<typename NodeT> void operator()(const NodeT *Node) {
 215     Depth += 2;
 216     fprintf(stderr, "%s(", itanium_demangle::NodeKind<NodeT>::name());
 217     Node->match(CtorArgPrinter{*this});
 218     fprintf(stderr, ")");
 219     Depth -= 2;
 220   }
 221
 222   void operator()(const ForwardTemplateReference *Node) {
 223     Depth += 2;
 224     fprintf(stderr, "ForwardTemplateReference(");
 225     if (Node->Ref && !Node->Printing) {
 226       Node->Printing = true;
 227       CtorArgPrinter{*this}(Node->Ref);
 228       Node->Printing = false;
 229     } else {
 230       CtorArgPrinter{*this}(Node->Index);
 231     }
 232     fprintf(stderr, ")");
 233     Depth -= 2;
 234   }
 235 };
 236 }
 237
 238 void itanium_demangle::Node::dump() const {
 239   DumpVisitor V;
 240   visit(std::ref(V));
 241   V.newLine();
 242 }
 243 #endif
 244
 245 namespace {
 246 class BumpPointerAllocator {
 247   struct BlockMeta {
 248     BlockMeta* Next;
 249     size_t Current;
 250   };
 251
 252   static constexpr size_t AllocSize = 4096;
 253   static constexpr size_t UsableAllocSize = AllocSize - sizeof(BlockMeta);
 254
 255   alignas(long double) char InitialBuffer[AllocSize];
 256   BlockMeta* BlockList = nullptr;
 257
 258   void grow() {
 259     char* NewMeta = static_cast<char *>(std::malloc(AllocSize));
 260     if (NewMeta == nullptr)
 261       std::terminate();
 262     BlockList = new (NewMeta) BlockMeta{BlockList, 0};
 263   }
 264
 265   void* allocateMassive(size_t NBytes) {
 266     NBytes += sizeof(BlockMeta);
 267     BlockMeta* NewMeta = reinterpret_cast<BlockMeta*>(std::malloc(NBytes));
 268     if (NewMeta == nullptr)
 269       std::terminate();
 270     BlockList->Next = new (NewMeta) BlockMeta{BlockList->Next, 0};
 271     return static_cast<void*>(NewMeta + 1);
 272   }
 273
 274 public:
 275   BumpPointerAllocator()
 276       : BlockList(new (InitialBuffer) BlockMeta{nullptr, 0}) {}
 277
 278   void* allocate(size_t N) {
 279     N = (N + 15u) & ~15u;
 280     if (N + BlockList->Current >= UsableAllocSize) {
 281       if (N > UsableAllocSize)
 282         return allocateMassive(N);
 283       grow();
 284     }
 285     BlockList->Current += N;
 286     return static_cast<void*>(reinterpret_cast<char*>(BlockList + 1) +
 287                               BlockList->Current - N);
 288   }
 289
 290   void reset() {
 291     while (BlockList) {
 292       BlockMeta* Tmp = BlockList;
 293       BlockList = BlockList->Next;
 294       if (reinterpret_cast<char*>(Tmp) != InitialBuffer)
 295         std::free(Tmp);
 296     }
 297     BlockList = new (InitialBuffer) BlockMeta{nullptr, 0};
 298   }
 299
 300   ~BumpPointerAllocator() { reset(); }
 301 };
 302
 303 class DefaultAllocator {
 304   BumpPointerAllocator Alloc;
 305
 306 public:
 307   void reset() { Alloc.reset(); }
 308
 309   template<typename T, typename ...Args> T *makeNode(Args &&...args) {
 310     return new (Alloc.allocate(sizeof(T)))
 311         T(std::forward<Args>(args)...);
 312   }
 313
 314   void *allocateNodeArray(size_t sz) {
 315     return Alloc.allocate(sizeof(Node *) * sz);
 316   }
 317 };
 318 }  // unnamed namespace
 319
 320 //===----------------------------------------------------------------------===//
 321 // Code beyond this point should not be synchronized with libc++abi.
 322 //===----------------------------------------------------------------------===//
 323
 324 using Demangler = itanium_demangle::ManglingParser<DefaultAllocator>;
 325
 326 char *llvm::itaniumDemangle(const char *MangledName, char *Buf,
 327                             size_t *N, int *Status) {
 328   if (MangledName == nullptr || (Buf != nullptr && N == nullptr)) {
 329     if (Status)
 330       *Status = demangle_invalid_args;
 331     return nullptr;
 332   }
 333
 334   int InternalStatus = demangle_success;
 335   Demangler Parser(MangledName, MangledName + std::strlen(MangledName));
 336   OutputStream S;
 337
 338   Node *AST = Parser.parse();
 339
 340   if (AST == nullptr)
 341     InternalStatus = demangle_invalid_mangled_name;
 342   else if (!initializeOutputStream(Buf, N, S, 1024))
 343     InternalStatus = demangle_memory_alloc_failure;
 344   else {
 345     assert(Parser.ForwardTemplateRefs.empty());
 346     AST->print(S);
 347     S += '\0';
 348     if (N != nullptr)
 349       *N = S.getCurrentPosition();
 350     Buf = S.getBuffer();
 351   }
 352
 353   if (Status)
 354     *Status = InternalStatus;
 355   return InternalStatus == demangle_success ? Buf : nullptr;
 356 }
 357
 358 ItaniumPartialDemangler::ItaniumPartialDemangler()
 359     : RootNode(nullptr), Context(new Demangler{nullptr, nullptr}) {}
 360
 361 ItaniumPartialDemangler::~ItaniumPartialDemangler() {
 362   delete static_cast<Demangler *>(Context);
 363 }
 364
 365 ItaniumPartialDemangler::ItaniumPartialDemangler(
 366     ItaniumPartialDemangler &&Other)
 367     : RootNode(Other.RootNode), Context(Other.Context) {
 368   Other.Context = Other.RootNode = nullptr;
 369 }
 370
 371 ItaniumPartialDemangler &ItaniumPartialDemangler::
 372 operator=(ItaniumPartialDemangler &&Other) {
 373   std::swap(RootNode, Other.RootNode);
 374   std::swap(Context, Other.Context);
 375   return *this;
 376 }
 377
 378 // Demangle MangledName into an AST, storing it into this->RootNode.
 379 bool ItaniumPartialDemangler::partialDemangle(const char *MangledName) {
 380   Demangler *Parser = static_cast<Demangler *>(Context);
 381   size_t Len = std::strlen(MangledName);
 382   Parser->reset(MangledName, MangledName + Len);
 383   RootNode = Parser->parse();
 384   return RootNode == nullptr;
 385 }
 386
 387 static char *printNode(const Node *RootNode, char *Buf, size_t *N) {
 388   OutputStream S;
 389   if (!initializeOutputStream(Buf, N, S, 128))
 390     return nullptr;
 391   RootNode->print(S);
 392   S += '\0';
 393   if (N != nullptr)
 394     *N = S.getCurrentPosition();
 395   return S.getBuffer();
 396 }
 397
 398 char *ItaniumPartialDemangler::getFunctionBaseName(char *Buf, size_t *N) const {
 399   if (!isFunction())
 400     return nullptr;
 401
 402   const Node *Name = static_cast<const FunctionEncoding *>(RootNode)->getName();
 403
 404   while (true) {
 405     switch (Name->getKind()) {
 406     case Node::KAbiTagAttr:
 407       Name = static_cast<const AbiTagAttr *>(Name)->Base;
 408       continue;
 409     case Node::KStdQualifiedName:
 410       Name = static_cast<const StdQualifiedName *>(Name)->Child;
 411       continue;
 412     case Node::KNestedName:
 413       Name = static_cast<const NestedName *>(Name)->Name;
 414       continue;
 415     case Node::KLocalName:
 416       Name = static_cast<const LocalName *>(Name)->Entity;
 417       continue;
 418     case Node::KNameWithTemplateArgs:
 419       Name = static_cast<const NameWithTemplateArgs *>(Name)->Name;
 420       continue;
 421     default:
 422       return printNode(Name, Buf, N);
 423     }
 424   }
 425 }
 426
 427 char *ItaniumPartialDemangler::getFunctionDeclContextName(char *Buf,
 428                                                           size_t *N) const {
 429   if (!isFunction())
 430     return nullptr;
 431   const Node *Name = static_cast<const FunctionEncoding *>(RootNode)->getName();
 432
 433   OutputStream S;
 434   if (!initializeOutputStream(Buf, N, S, 128))
 435     return nullptr;
 436
 437  KeepGoingLocalFunction:
 438   while (true) {
 439     if (Name->getKind() == Node::KAbiTagAttr) {
 440       Name = static_cast<const AbiTagAttr *>(Name)->Base;
 441       continue;
 442     }
 443     if (Name->getKind() == Node::KNameWithTemplateArgs) {
 444       Name = static_cast<const NameWithTemplateArgs *>(Name)->Name;
 445       continue;
 446     }
 447     break;
 448   }
 449
 450   switch (Name->getKind()) {
 451   case Node::KStdQualifiedName:
 452     S += "std";
 453     break;
 454   case Node::KNestedName:
 455     static_cast<const NestedName *>(Name)->Qual->print(S);
 456     break;
 457   case Node::KLocalName: {
 458     auto *LN = static_cast<const LocalName *>(Name);
 459     LN->Encoding->print(S);
 460     S += "::";
 461     Name = LN->Entity;
 462     goto KeepGoingLocalFunction;
 463   }
 464   default:
 465     break;
 466   }
 467   S += '\0';
 468   if (N != nullptr)
 469     *N = S.getCurrentPosition();
 470   return S.getBuffer();
 471 }
 472
 473 char *ItaniumPartialDemangler::getFunctionName(char *Buf, size_t *N) const {
 474   if (!isFunction())
 475     return nullptr;
 476   auto *Name = static_cast<FunctionEncoding *>(RootNode)->getName();
 477   return printNode(Name, Buf, N);
 478 }
 479
 480 char *ItaniumPartialDemangler::getFunctionParameters(char *Buf,
 481                                                      size_t *N) const {
 482   if (!isFunction())
 483     return nullptr;
 484   NodeArray Params = static_cast<FunctionEncoding *>(RootNode)->getParams();
 485
 486   OutputStream S;
 487   if (!initializeOutputStream(Buf, N, S, 128))
 488     return nullptr;
 489
 490   S += '(';
 491   Params.printWithComma(S);
 492   S += ')';
 493   S += '\0';
 494   if (N != nullptr)
 495     *N = S.getCurrentPosition();
 496   return S.getBuffer();
 497 }
 498
 499 char *ItaniumPartialDemangler::getFunctionReturnType(
 500     char *Buf, size_t *N) const {
 501   if (!isFunction())
 502     return nullptr;
 503
 504   OutputStream S;
 505   if (!initializeOutputStream(Buf, N, S, 128))
 506     return nullptr;
 507
 508   if (const Node *Ret =
 509           static_cast<const FunctionEncoding *>(RootNode)->getReturnType())
 510     Ret->print(S);
 511
 512   S += '\0';
 513   if (N != nullptr)
 514     *N = S.getCurrentPosition();
 515   return S.getBuffer();
 516 }
 517
 518 char *ItaniumPartialDemangler::finishDemangle(char *Buf, size_t *N) const {
 519   assert(RootNode != nullptr && "must call partialDemangle()");
 520   return printNode(static_cast<Node *>(RootNode), Buf, N);
 521 }
 522
 523 bool ItaniumPartialDemangler::hasFunctionQualifiers() const {
 524   assert(RootNode != nullptr && "must call partialDemangle()");
 525   if (!isFunction())
 526     return false;
 527   auto *E = static_cast<const FunctionEncoding *>(RootNode);
 528   return E->getCVQuals() != QualNone || E->getRefQual() != FrefQualNone;
 529 }
 530
 531 bool ItaniumPartialDemangler::isCtorOrDtor() const {
 532   const Node *N = static_cast<const Node *>(RootNode);
 533   while (N) {
 534     switch (N->getKind()) {
 535     default:
 536       return false;
 537     case Node::KCtorDtorName:
 538       return true;
 539
 540     case Node::KAbiTagAttr:
 541       N = static_cast<const AbiTagAttr *>(N)->Base;
 542       break;
 543     case Node::KFunctionEncoding:
 544       N = static_cast<const FunctionEncoding *>(N)->getName();
 545       break;
 546     case Node::KLocalName:
 547       N = static_cast<const LocalName *>(N)->Entity;
 548       break;
 549     case Node::KNameWithTemplateArgs:
 550       N = static_cast<const NameWithTemplateArgs *>(N)->Name;
 551       break;
 552     case Node::KNestedName:
 553       N = static_cast<const NestedName *>(N)->Name;
 554       break;
 555     case Node::KStdQualifiedName:
 556       N = static_cast<const StdQualifiedName *>(N)->Child;
 557       break;
 558     }
 559   }
 560   return false;
 561 }
 562
 563 bool ItaniumPartialDemangler::isFunction() const {
 564   assert(RootNode != nullptr && "must call partialDemangle()");
 565   return static_cast<const Node *>(RootNode)->getKind() ==
 566          Node::KFunctionEncoding;
 567 }
 568
 569 bool ItaniumPartialDemangler::isSpecialName() const {
 570   assert(RootNode != nullptr && "must call partialDemangle()");
 571   auto K = static_cast<const Node *>(RootNode)->getKind();
 572   return K == Node::KSpecialName || K == Node::KCtorVtableSpecialName;
 573 }
 574
 575 bool ItaniumPartialDemangler::isData() const {
 576   return !isFunction() && !isSpecialName();
 577 }