libcxxabi/src/cxa_demangle.cpp

   1 //===----------------------------------------------------------------------===//
   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 "demangle/ItaniumDemangle.h"
  14 #include "__cxxabi_config.h"
  15 #include <cassert>
  16 #include <cctype>
  17 #include <cstdio>
  18 #include <cstdlib>
  19 #include <cstring>
  20 #include <functional>
  21 #include <numeric>
  22 #include <utility>
  23
  24 using namespace itanium_demangle;
  25
  26 constexpr const char *itanium_demangle::FloatData<float>::spec;
  27 constexpr const char *itanium_demangle::FloatData<double>::spec;
  28 constexpr const char *itanium_demangle::FloatData<long double>::spec;
  29
  30 // <discriminator> := _ <non-negative number>      # when number < 10
  31 //                 := __ <non-negative number> _   # when number >= 10
  32 //  extension      := decimal-digit+               # at the end of string
  33 const char *itanium_demangle::parse_discriminator(const char *first,
  34                                                   const char *last) {
  35   // parse but ignore discriminator
  36   if (first != last) {
  37     if (*first == '_') {
  38       const char *t1 = first + 1;
  39       if (t1 != last) {
  40         if (std::isdigit(*t1))
  41           first = t1 + 1;
  42         else if (*t1 == '_') {
  43           for (++t1; t1 != last && std::isdigit(*t1); ++t1)
  44             ;
  45           if (t1 != last && *t1 == '_')
  46             first = t1 + 1;
  47         }
  48       }
  49     } else if (std::isdigit(*first)) {
  50       const char *t1 = first + 1;
  51       for (; t1 != last && std::isdigit(*t1); ++t1)
  52         ;
  53       if (t1 == last)
  54         first = last;
  55     }
  56   }
  57   return first;
  58 }
  59
  60 #ifndef NDEBUG
  61 namespace {
  62 struct DumpVisitor {
  63   unsigned Depth = 0;
  64   bool PendingNewline = false;
  65
  66   template<typename NodeT> static constexpr bool wantsNewline(const NodeT *) {
  67     return true;
  68   }
  69   static bool wantsNewline(NodeArray A) { return !A.empty(); }
  70   static constexpr bool wantsNewline(...) { return false; }
  71
  72   template<typename ...Ts> static bool anyWantNewline(Ts ...Vs) {
  73     for (bool B : {wantsNewline(Vs)...})
  74       if (B)
  75         return true;
  76     return false;
  77   }
  78
  79   void printStr(const char *S) { fprintf(stderr, "%s", S); }
  80   void print(StringView SV) {
  81     fprintf(stderr, "\"%.*s\"", (int)SV.size(), SV.begin());
  82   }
  83   void print(const Node *N) {
  84     if (N)
  85       N->visit(std::ref(*this));
  86     else
  87       printStr("<null>");
  88   }
  89   void print(NodeArray A) {
  90     ++Depth;
  91     printStr("{");
  92     bool First = true;
  93     for (const Node *N : A) {
  94       if (First)
  95         print(N);
  96       else
  97         printWithComma(N);
  98       First = false;
  99     }
 100     printStr("}");
 101     --Depth;
 102   }
 103
 104   // Overload used when T is exactly 'bool', not merely convertible to 'bool'.
 105   void print(bool B) { printStr(B ? "true" : "false"); }
 106
 107   template <class T>
 108   typename std::enable_if<std::is_unsigned<T>::value>::type print(T N) {
 109     fprintf(stderr, "%llu", (unsigned long long)N);
 110   }
 111
 112   template <class T>
 113   typename std::enable_if<std::is_signed<T>::value>::type print(T N) {
 114     fprintf(stderr, "%lld", (long long)N);
 115   }
 116
 117   void print(ReferenceKind RK) {
 118     switch (RK) {
 119     case ReferenceKind::LValue:
 120       return printStr("ReferenceKind::LValue");
 121     case ReferenceKind::RValue:
 122       return printStr("ReferenceKind::RValue");
 123     }
 124   }
 125   void print(FunctionRefQual RQ) {
 126     switch (RQ) {
 127     case FunctionRefQual::FrefQualNone:
 128       return printStr("FunctionRefQual::FrefQualNone");
 129     case FunctionRefQual::FrefQualLValue:
 130       return printStr("FunctionRefQual::FrefQualLValue");
 131     case FunctionRefQual::FrefQualRValue:
 132       return printStr("FunctionRefQual::FrefQualRValue");
 133     }
 134   }
 135   void print(Qualifiers Qs) {
 136     if (!Qs) return printStr("QualNone");
 137     struct QualName { Qualifiers Q; const char *Name; } Names[] = {
 138       {QualConst, "QualConst"},
 139       {QualVolatile, "QualVolatile"},
 140       {QualRestrict, "QualRestrict"},
 141     };
 142     for (QualName Name : Names) {
 143       if (Qs & Name.Q) {
 144         printStr(Name.Name);
 145         Qs = Qualifiers(Qs & ~Name.Q);
 146         if (Qs) printStr(" | ");
 147       }
 148     }
 149   }
 150   void print(SpecialSubKind SSK) {
 151     switch (SSK) {
 152     case SpecialSubKind::allocator:
 153       return printStr("SpecialSubKind::allocator");
 154     case SpecialSubKind::basic_string:
 155       return printStr("SpecialSubKind::basic_string");
 156     case SpecialSubKind::string:
 157       return printStr("SpecialSubKind::string");
 158     case SpecialSubKind::istream:
 159       return printStr("SpecialSubKind::istream");
 160     case SpecialSubKind::ostream:
 161       return printStr("SpecialSubKind::ostream");
 162     case SpecialSubKind::iostream:
 163       return printStr("SpecialSubKind::iostream");
 164     }
 165   }
 166   void print(TemplateParamKind TPK) {
 167     switch (TPK) {
 168     case TemplateParamKind::Type:
 169       return printStr("TemplateParamKind::Type");
 170     case TemplateParamKind::NonType:
 171       return printStr("TemplateParamKind::NonType");
 172     case TemplateParamKind::Template:
 173       return printStr("TemplateParamKind::Template");
 174     }
 175   }
 176   void print(Node::Prec P) {
 177     switch (P) {
 178     case Node::Prec::Primary:
 179       return printStr("Node::Prec::Primary");
 180     case Node::Prec::Postfix:
 181       return printStr("Node::Prec::Postfix");
 182     case Node::Prec::Unary:
 183       return printStr("Node::Prec::Unary");
 184     case Node::Prec::Cast:
 185       return printStr("Node::Prec::Cast");
 186     case Node::Prec::PtrMem:
 187       return printStr("Node::Prec::PtrMem");
 188     case Node::Prec::Multiplicative:
 189       return printStr("Node::Prec::Multiplicative");
 190     case Node::Prec::Additive:
 191       return printStr("Node::Prec::Additive");
 192     case Node::Prec::Shift:
 193       return printStr("Node::Prec::Shift");
 194     case Node::Prec::Spaceship:
 195       return printStr("Node::Prec::Spaceship");
 196     case Node::Prec::Relational:
 197       return printStr("Node::Prec::Relational");
 198     case Node::Prec::Equality:
 199       return printStr("Node::Prec::Equality");
 200     case Node::Prec::And:
 201       return printStr("Node::Prec::And");
 202     case Node::Prec::Xor:
 203       return printStr("Node::Prec::Xor");
 204     case Node::Prec::Ior:
 205       return printStr("Node::Prec::Ior");
 206     case Node::Prec::AndIf:
 207       return printStr("Node::Prec::AndIf");
 208     case Node::Prec::OrIf:
 209       return printStr("Node::Prec::OrIf");
 210     case Node::Prec::Conditional:
 211       return printStr("Node::Prec::Conditional");
 212     case Node::Prec::Assign:
 213       return printStr("Node::Prec::Assign");
 214     case Node::Prec::Comma:
 215       return printStr("Node::Prec::Comma");
 216     case Node::Prec::Default:
 217       return printStr("Node::Prec::Default");
 218     }
 219   }
 220
 221   void newLine() {
 222     printStr("\n");
 223     for (unsigned I = 0; I != Depth; ++I)
 224       printStr(" ");
 225     PendingNewline = false;
 226   }
 227
 228   template<typename T> void printWithPendingNewline(T V) {
 229     print(V);
 230     if (wantsNewline(V))
 231       PendingNewline = true;
 232   }
 233
 234   template<typename T> void printWithComma(T V) {
 235     if (PendingNewline || wantsNewline(V)) {
 236       printStr(",");
 237       newLine();
 238     } else {
 239       printStr(", ");
 240     }
 241
 242     printWithPendingNewline(V);
 243   }
 244
 245   struct CtorArgPrinter {
 246     DumpVisitor &Visitor;
 247
 248     template<typename T, typename ...Rest> void operator()(T V, Rest ...Vs) {
 249       if (Visitor.anyWantNewline(V, Vs...))
 250         Visitor.newLine();
 251       Visitor.printWithPendingNewline(V);
 252       int PrintInOrder[] = { (Visitor.printWithComma(Vs), 0)..., 0 };
 253       (void)PrintInOrder;
 254     }
 255   };
 256
 257   template<typename NodeT> void operator()(const NodeT *Node) {
 258     Depth += 2;
 259     fprintf(stderr, "%s(", itanium_demangle::NodeKind<NodeT>::name());
 260     Node->match(CtorArgPrinter{*this});
 261     fprintf(stderr, ")");
 262     Depth -= 2;
 263   }
 264
 265   void operator()(const ForwardTemplateReference *Node) {
 266     Depth += 2;
 267     fprintf(stderr, "ForwardTemplateReference(");
 268     if (Node->Ref && !Node->Printing) {
 269       Node->Printing = true;
 270       CtorArgPrinter{*this}(Node->Ref);
 271       Node->Printing = false;
 272     } else {
 273       CtorArgPrinter{*this}(Node->Index);
 274     }
 275     fprintf(stderr, ")");
 276     Depth -= 2;
 277   }
 278 };
 279 }
 280
 281 void itanium_demangle::Node::dump() const {
 282   DumpVisitor V;
 283   visit(std::ref(V));
 284   V.newLine();
 285 }
 286 #endif
 287
 288 namespace {
 289 class BumpPointerAllocator {
 290   struct BlockMeta {
 291     BlockMeta* Next;
 292     size_t Current;
 293   };
 294
 295   static constexpr size_t AllocSize = 4096;
 296   static constexpr size_t UsableAllocSize = AllocSize - sizeof(BlockMeta);
 297
 298   alignas(long double) char InitialBuffer[AllocSize];
 299   BlockMeta* BlockList = nullptr;
 300
 301   void grow() {
 302     char* NewMeta = static_cast<char *>(std::malloc(AllocSize));
 303     if (NewMeta == nullptr)
 304       std::terminate();
 305     BlockList = new (NewMeta) BlockMeta{BlockList, 0};
 306   }
 307
 308   void* allocateMassive(size_t NBytes) {
 309     NBytes += sizeof(BlockMeta);
 310     BlockMeta* NewMeta = reinterpret_cast<BlockMeta*>(std::malloc(NBytes));
 311     if (NewMeta == nullptr)
 312       std::terminate();
 313     BlockList->Next = new (NewMeta) BlockMeta{BlockList->Next, 0};
 314     return static_cast<void*>(NewMeta + 1);
 315   }
 316
 317 public:
 318   BumpPointerAllocator()
 319       : BlockList(new (InitialBuffer) BlockMeta{nullptr, 0}) {}
 320
 321   void* allocate(size_t N) {
 322     N = (N + 15u) & ~15u;
 323     if (N + BlockList->Current >= UsableAllocSize) {
 324       if (N > UsableAllocSize)
 325         return allocateMassive(N);
 326       grow();
 327     }
 328     BlockList->Current += N;
 329     return static_cast<void*>(reinterpret_cast<char*>(BlockList + 1) +
 330                               BlockList->Current - N);
 331   }
 332
 333   void reset() {
 334     while (BlockList) {
 335       BlockMeta* Tmp = BlockList;
 336       BlockList = BlockList->Next;
 337       if (reinterpret_cast<char*>(Tmp) != InitialBuffer)
 338         std::free(Tmp);
 339     }
 340     BlockList = new (InitialBuffer) BlockMeta{nullptr, 0};
 341   }
 342
 343   ~BumpPointerAllocator() { reset(); }
 344 };
 345
 346 class DefaultAllocator {
 347   BumpPointerAllocator Alloc;
 348
 349 public:
 350   void reset() { Alloc.reset(); }
 351
 352   template<typename T, typename ...Args> T *makeNode(Args &&...args) {
 353     return new (Alloc.allocate(sizeof(T)))
 354         T(std::forward<Args>(args)...);
 355   }
 356
 357   void *allocateNodeArray(size_t sz) {
 358     return Alloc.allocate(sizeof(Node *) * sz);
 359   }
 360 };
 361 }  // unnamed namespace
 362
 363 //===----------------------------------------------------------------------===//
 364 // Code beyond this point should not be synchronized with LLVM.
 365 //===----------------------------------------------------------------------===//
 366
 367 using Demangler = itanium_demangle::ManglingParser<DefaultAllocator>;
 368
 369 namespace {
 370 enum : int {
 371   demangle_invalid_args = -3,
 372   demangle_invalid_mangled_name = -2,
 373   demangle_memory_alloc_failure = -1,
 374   demangle_success = 0,
 375 };
 376 }
 377
 378 namespace __cxxabiv1 {
 379 extern "C" _LIBCXXABI_FUNC_VIS char *
 380 __cxa_demangle(const char *MangledName, char *Buf, size_t *N, int *Status) {
 381   if (MangledName == nullptr || (Buf != nullptr && N == nullptr)) {
 382     if (Status)
 383       *Status = demangle_invalid_args;
 384     return nullptr;
 385   }
 386
 387   int InternalStatus = demangle_success;
 388   Demangler Parser(MangledName, MangledName + std::strlen(MangledName));
 389   OutputBuffer O;
 390
 391   Node *AST = Parser.parse();
 392
 393   if (AST == nullptr)
 394     InternalStatus = demangle_invalid_mangled_name;
 395   else if (!initializeOutputBuffer(Buf, N, O, 1024))
 396     InternalStatus = demangle_memory_alloc_failure;
 397   else {
 398     assert(Parser.ForwardTemplateRefs.empty());
 399     AST->print(O);
 400     O += '\0';
 401     if (N != nullptr)
 402       *N = O.getCurrentPosition();
 403     Buf = O.getBuffer();
 404   }
 405
 406   if (Status)
 407     *Status = InternalStatus;
 408   return InternalStatus == demangle_success ? Buf : nullptr;
 409 }
 410 }  // __cxxabiv1