llvm-cxxfilt: Demangle gcc "old-style unified" ctors and dtors

[thakis]

Summary

These are variant 4, cf
https://github.com/gcc-mirror/gcc/blob/master/gcc/cp/mangle.c#L1851
https://github.com/gcc-mirror/gcc/blob/master/gcc/cp/mangle.c#L1880
and gcc seems to sometimes emit them still.

[erik.pilkington]

LGTM, thanks!

[erik.pilkington]

libcxxabi/src/demangle/ItaniumDemangle.h

2796 ↗

(On Diff #193576)

Can you also update the BNF here?

libcxxabi/trunk/src/demangle/ItaniumDemangle.h

case 'v':
     return nullptr;
   }
   return nullptr;
 }
 
 // <ctor-dtor-name> ::= C1  # complete object constructor
 //                  ::= C2  # base object constructor
 //                  ::= C3  # complete object allocating constructor
-//   extension      ::= C5    # ?
+//   extension      ::= C4  # gcc old-style "[unified]" constructor
+//   extension      ::= C5  # the COMDAT used for ctors
 //                  ::= D0  # deleting destructor
 //                  ::= D1  # complete object destructor
 //                  ::= D2  # base object destructor
-//   extension      ::= D5    # ?
+//   extension      ::= D4  # gcc old-style "[unified]" destructor
+//   extension      ::= D5  # the COMDAT used for dtors
 template <typename Derived, typename Alloc>
 Node *
 AbstractManglingParser<Derived, Alloc>::parseCtorDtorName(Node *&SoFar,
                                                           NameState *State) {
   if (SoFar->getKind() == Node::KSpecialSubstitution) {
     auto SSK = static_cast<SpecialSubstitution *>(SoFar)->SSK;
     switch (SSK) {
     case SpecialSubKind::string:
     case SpecialSubKind::istream:
     case SpecialSubKind::ostream:
     case SpecialSubKind::iostream:
       SoFar = make<ExpandedSpecialSubstitution>(SSK);
       if (!SoFar)
         return nullptr;
       break;
     default:
       break;
     }
   }
 
   if (consumeIf('C')) {
     bool IsInherited = consumeIf('I');
-    if (look() != '1' && look() != '2' && look() != '3' && look() != '5')
+    if (look() != '1' && look() != '2' && look() != '3' && look() != '4' &&
+        look() != '5')
       return nullptr;
     int Variant = look() - '0';
     ++First;
     if (State) State->CtorDtorConversion = true;
     if (IsInherited) {
       if (getDerived().parseName(State) == nullptr)
         return nullptr;
     }
-    return make<CtorDtorName>(SoFar, false, Variant);
+    return make<CtorDtorName>(SoFar, /*IsDtor=*/false, Variant);
   }
 
-  if (look() == 'D' &&
-      (look(1) == '0' || look(1) == '1' || look(1) == '2' || look(1) == '5')) {
+  if (look() == 'D' && (look(1) == '0' || look(1) == '1' || look(1) == '2' ||
+                        look(1) == '4' || look(1) == '5')) {
     int Variant = look(1) - '0';
     First += 2;
     if (State) State->CtorDtorConversion = true;
-    return make<CtorDtorName>(SoFar, true, Variant);
+    return make<CtorDtorName>(SoFar, /*IsDtor=*/true, Variant);
   }
 
   return nullptr;
 }
 
 // <nested-name> ::= N [<CV-Qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
 //               ::= N [<CV-Qualifiers>] [<ref-qualifier>] <template-prefix> <template-args> E
 //

libcxxabi/trunk/test/test_demangle.pass.cpp

const char* cases[][2] =
     {"_ZN5clang14ASTMergeActionD2Ev", "clang::ASTMergeAction::~ASTMergeAction()"},
     {"_ZNK5clang14ASTMergeAction20usesPreprocessorOnlyEv", "clang::ASTMergeAction::usesPreprocessorOnly() const"},
     {"_ZN5clang14ASTMergeAction27usesCompleteTranslationUnitEv", "clang::ASTMergeAction::usesCompleteTranslationUnit()"},
     {"_ZNK5clang14ASTMergeAction13hasPCHSupportEv", "clang::ASTMergeAction::hasPCHSupport() const"},
     {"_ZNK5clang14ASTMergeAction17hasASTFileSupportEv", "clang::ASTMergeAction::hasASTFileSupport() const"},
     {"_ZNK5clang14ASTMergeAction24hasCodeCompletionSupportEv", "clang::ASTMergeAction::hasCodeCompletionSupport() const"},
     {"_ZN5clang7ASTUnitC1Eb", "clang::ASTUnit::ASTUnit(bool)"},
     {"_ZN5clang7ASTUnitC2Eb", "clang::ASTUnit::ASTUnit(bool)"},
+    {"_ZN5clang7ASTUnitC3Eb", "clang::ASTUnit::ASTUnit(bool)"},
+    {"_ZN5clang7ASTUnitC4Eb", "clang::ASTUnit::ASTUnit(bool)"},
+    {"_ZN5clang7ASTUnitC5Eb", "clang::ASTUnit::ASTUnit(bool)"},
+    {"_ZN5clang7ASTUnitD0Ev", "clang::ASTUnit::~ASTUnit()"},
     {"_ZN5clang7ASTUnitD1Ev", "clang::ASTUnit::~ASTUnit()"},
     {"_ZN5clang7ASTUnitD2Ev", "clang::ASTUnit::~ASTUnit()"},
+    {"_ZN5clang7ASTUnitD4Ev", "clang::ASTUnit::~ASTUnit()"},
+    {"_ZN5clang7ASTUnitD5Ev", "clang::ASTUnit::~ASTUnit()"},
     {"_ZN5clang7ASTUnit19CleanTemporaryFilesEv", "clang::ASTUnit::CleanTemporaryFiles()"},
     {"_ZN5clang7ASTUnit28ClearCachedCompletionResultsEv", "clang::ASTUnit::ClearCachedCompletionResults()"},
     {"_ZN5clang7ASTUnit26CacheCodeCompletionResultsEv", "clang::ASTUnit::CacheCodeCompletionResults()"},
     {"_ZNK5clang7ASTUnit15getMainFileNameEv", "clang::ASTUnit::getMainFileName() const"},
     {"_ZN12_GLOBAL__N_111SimpleTimerD1Ev", "(anonymous namespace)::SimpleTimer::~SimpleTimer()"},
     {"_ZN5clang7ASTUnit25getOriginalSourceFileNameEv", "clang::ASTUnit::getOriginalSourceFileName()"},
     {"_ZN5clang7ASTUnit14getASTFileNameEv", "clang::ASTUnit::getASTFileName()"},
     {"_ZN5clang7ASTUnit16getBufferForFileEN4llvm9StringRefEPSs", "clang::ASTUnit::getBufferForFile(llvm::StringRef, std::string*)"},

llvm/trunk/include/llvm/Demangle/ItaniumDemangle.h

case 'v':
     return nullptr;
   }
   return nullptr;
 }
 
 // <ctor-dtor-name> ::= C1  # complete object constructor
 //                  ::= C2  # base object constructor
 //                  ::= C3  # complete object allocating constructor
-//   extension      ::= C5    # ?
+//   extension      ::= C4  # gcc old-style "[unified]" constructor
+//   extension      ::= C5  # the COMDAT used for ctors
 //                  ::= D0  # deleting destructor
 //                  ::= D1  # complete object destructor
 //                  ::= D2  # base object destructor
-//   extension      ::= D5    # ?
+//   extension      ::= D4  # gcc old-style "[unified]" destructor
+//   extension      ::= D5  # the COMDAT used for dtors
 template <typename Derived, typename Alloc>
 Node *
 AbstractManglingParser<Derived, Alloc>::parseCtorDtorName(Node *&SoFar,
                                                           NameState *State) {
   if (SoFar->getKind() == Node::KSpecialSubstitution) {
     auto SSK = static_cast<SpecialSubstitution *>(SoFar)->SSK;
     switch (SSK) {
     case SpecialSubKind::string:
     case SpecialSubKind::istream:
     case SpecialSubKind::ostream:
     case SpecialSubKind::iostream:
       SoFar = make<ExpandedSpecialSubstitution>(SSK);
       if (!SoFar)
         return nullptr;
       break;
     default:
       break;
     }
   }
 
   if (consumeIf('C')) {
     bool IsInherited = consumeIf('I');
-    if (look() != '1' && look() != '2' && look() != '3' && look() != '5')
+    if (look() != '1' && look() != '2' && look() != '3' && look() != '4' &&
+        look() != '5')
       return nullptr;
     int Variant = look() - '0';
     ++First;
     if (State) State->CtorDtorConversion = true;
     if (IsInherited) {
       if (getDerived().parseName(State) == nullptr)
         return nullptr;
     }
-    return make<CtorDtorName>(SoFar, false, Variant);
+    return make<CtorDtorName>(SoFar, /*IsDtor=*/false, Variant);
   }
 
-  if (look() == 'D' &&
-      (look(1) == '0' || look(1) == '1' || look(1) == '2' || look(1) == '5')) {
+  if (look() == 'D' && (look(1) == '0' || look(1) == '1' || look(1) == '2' ||
+                        look(1) == '4' || look(1) == '5')) {
     int Variant = look(1) - '0';
     First += 2;
     if (State) State->CtorDtorConversion = true;
-    return make<CtorDtorName>(SoFar, true, Variant);
+    return make<CtorDtorName>(SoFar, /*IsDtor=*/true, Variant);
   }
 
   return nullptr;
 }
 
 // <nested-name> ::= N [<CV-Qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
 //               ::= N [<CV-Qualifiers>] [<ref-qualifier>] <template-prefix> <template-args> E
 //