Mangling: Add a mangling for #_hasSymbol query functions.

Author: tshortli

docs/ABI/Mangling.rst

@@ -157,11 +157,11 @@ Globals
   global ::= protocol-conformance 'MA'   // metadata for remote mirrors: associated type descriptor
   global ::= nominal-type 'MC'           // metadata for remote mirrors: superclass descriptor
 
-  // TODO check this::
   global ::= mangled-name 'TA'                     // partial application forwarder
   global ::= mangled-name 'Ta'                     // ObjC partial application forwarder
   global ::= mangled-name 'TQ' index               // Async await continuation partial function
   global ::= mangled-name 'TY' index               // Async suspend continuation partial function
+  global ::= mangled-name 'TwS'                    // #_hasSymbol query function
 
   global ::= type 'w' VALUE-WITNESS-KIND // value witness
 

include/swift/AST/ASTMangler.h

@@ -157,6 +157,7 @@ class ASTMangler : public Mangler {
     AccessibleFunctionRecord,
     BackDeploymentThunk,
     BackDeploymentFallback,
+    HasSymbolQuery,
   };
 
   /// lldb overrides the defaulted argument to 'true'.
@@ -357,6 +358,8 @@ class ASTMangler : public Mangler {
 
   std::string mangleGenericSignature(const GenericSignature sig);
 
+  std::string mangleHasSymbolQuery(const ValueDecl *decl);
+
   enum SpecialContext {
     ObjCContext,
     ClangImporterContext,

include/swift/Demangling/DemangleNodes.def

@@ -344,7 +344,9 @@ NODE(UniqueExtendedExistentialTypeShapeSymbolicReference)
 NODE(NonUniqueExtendedExistentialTypeShapeSymbolicReference)
 NODE(SymbolicExtendedExistentialType)
 
+// Added in Swift 5.8
 NODE(MetatypeParamsRemoved)
+NODE(HasSymbolQuery)
 
 #undef CONTEXT_NODE
 #undef NODE

lib/AST/ASTMangler.cpp

@@ -861,6 +861,28 @@ std::string ASTMangler::mangleGenericSignature(const GenericSignature sig) {
   return finalize();
 }
 
+std::string ASTMangler::mangleHasSymbolQuery(const ValueDecl *Decl) {
+  beginMangling();
+
+  if (auto Ctor = dyn_cast<ConstructorDecl>(Decl)) {
+    appendConstructorEntity(Ctor, /*isAllocating=*/false);
+  } else if (auto Dtor = dyn_cast<DestructorDecl>(Decl)) {
+    appendDestructorEntity(Dtor, /*isDeallocating=*/false);
+  } else if (auto GTD = dyn_cast<GenericTypeDecl>(Decl)) {
+    appendAnyGenericType(GTD);
+  } else if (isa<AssociatedTypeDecl>(Decl)) {
+    appendContextOf(Decl);
+    appendDeclName(Decl);
+    appendOperator("Qa");
+  } else {
+    appendEntity(Decl);
+  }
+
+  appendSymbolKind(ASTMangler::SymbolKind::HasSymbolQuery);
+
+  return finalize();
+}
+
 void ASTMangler::appendSymbolKind(SymbolKind SKind) {
   switch (SKind) {
     case SymbolKind::Default: return;
@@ -872,6 +894,7 @@ void ASTMangler::appendSymbolKind(SymbolKind SKind) {
     case SymbolKind::AccessibleFunctionRecord: return appendOperator("HF");
     case SymbolKind::BackDeploymentThunk: return appendOperator("Twb");
     case SymbolKind::BackDeploymentFallback: return appendOperator("TwB");
+    case SymbolKind::HasSymbolQuery: return appendOperator("TwS");
   }
 }
 

lib/Demangling/Demangler.cpp

@@ -145,6 +145,7 @@ bool swift::Demangle::isFunctionAttr(Node::Kind kind) {
     case Node::Kind::AccessibleFunctionRecord:
     case Node::Kind::BackDeploymentThunk:
     case Node::Kind::BackDeploymentFallback:
+    case Node::Kind::HasSymbolQuery:
       return true;
     default:
       return false;
@@ -2675,6 +2676,7 @@ NodePointer Demangler::demangleThunkOrSpecialization() {
       switch (nextChar()) {
       case 'b': return createNode(Node::Kind::BackDeploymentThunk);
       case 'B': return createNode(Node::Kind::BackDeploymentFallback);
+      case 'S': return createNode(Node::Kind::HasSymbolQuery);
       default:
         return nullptr;
       }

lib/Demangling/NodePrinter.cpp

@@ -604,6 +604,7 @@ class NodePrinter {
     case Node::Kind::UniqueExtendedExistentialTypeShapeSymbolicReference:
     case Node::Kind::NonUniqueExtendedExistentialTypeShapeSymbolicReference:
     case Node::Kind::SymbolicExtendedExistentialType:
+    case Node::Kind::HasSymbolQuery:
       return false;
     }
     printer_unreachable("bad node kind");
@@ -3046,6 +3047,9 @@ NodePointer NodePrinter::print(NodePointer Node, unsigned depth,
 
     return nullptr;
   }
+  case Node::Kind::HasSymbolQuery:
+    Printer << "#_hasSymbol query for ";
+    return nullptr;
   }
 
   printer_unreachable("bad node kind!");

lib/Demangling/OldRemangler.cpp

@@ -2854,3 +2854,8 @@ ManglingError Remangler::mangleBackDeploymentFallback(Node *node,
   Buffer << "TwB";
   return ManglingError::Success;
 }
+
+ManglingError Remangler::mangleHasSymbolQuery(Node *node, unsigned depth) {
+  Buffer << "TwS";
+  return ManglingError::Success;
+}

lib/Demangling/Remangler.cpp

@@ -1669,6 +1669,7 @@ ManglingError Remangler::mangleGlobal(Node *node, unsigned depth) {
       case Node::Kind::AccessibleFunctionRecord:
       case Node::Kind::BackDeploymentThunk:
       case Node::Kind::BackDeploymentFallback:
+      case Node::Kind::HasSymbolQuery:
         mangleInReverseOrder = true;
         break;
       default:
@@ -3503,6 +3504,11 @@ ManglingError Remangler::mangleExtendedExistentialTypeShape(Node *node,
   return ManglingError::Success;
 }
 
+ManglingError Remangler::mangleHasSymbolQuery(Node *node, unsigned depth) {
+  Buffer << "TwS";
+  return ManglingError::Success;
+}
+
 ManglingError Remangler::mangleSymbolicExtendedExistentialType(Node *node,
                                                      unsigned int depth) {
   RETURN_IF_ERROR(mangle(node->getChild(0), depth+1));

test/Demangle/Inputs/manglings.txt

@@ -439,3 +439,5 @@ $sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTQ0_ ---> {T:} (1) awai
 $sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTY0_ ---> {T:} (1) suspend resume partial function for reabstraction thunk helper <A, B where A: Swift.Sendable, B == Swift.Never> from @escaping @callee_guaranteed @Sendable @async () -> (@out A) to @escaping @callee_guaranteed @async () -> (@out A, @error @owned Swift.Error)
 $sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTY_ ---> {T:} (0) suspend resume partial function for reabstraction thunk helper <A, B where A: Swift.Sendable, B == Swift.Never> from @escaping @callee_guaranteed @Sendable @async () -> (@out A) to @escaping @callee_guaranteed @async () -> (@out A, @error @owned Swift.Error)
 $sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTQ12_ ---> {T:} (13) await resume partial function for reabstraction thunk helper <A, B where A: Swift.Sendable, B == Swift.Never> from @escaping @callee_guaranteed @Sendable @async () -> (@out A) to @escaping @callee_guaranteed @async () -> (@out A, @error @owned Swift.Error)
+$s7Library3fooyyFTwS ---> #_hasSymbol query for Library.foo() -> ()
+$s7Library5KlassCTwS ---> #_hasSymbol query for Library.Klass