IRGen: Set the mangler's generic signature correctly

Otherwise, we'll fall over if we try to mangle a retroactive conformance.

Fixes <rdar://problem/70483417>.

Author: slavapestov

lib/IRGen/GenReflection.cpp

@@ -308,7 +308,7 @@ getTypeRefImpl(IRGenModule &IGM,
   }
 
   IRGenMangler Mangler;
-  auto SymbolicName = Mangler.mangleTypeForReflection(IGM, type);
+  auto SymbolicName = Mangler.mangleTypeForReflection(IGM, sig, type);
   return {IGM.getAddrOfStringForTypeRef(SymbolicName, role),
           SymbolicName.runtimeSizeInBytes()};
 }
@@ -628,25 +628,21 @@ class AssociatedTypeMetadataBuilder : public ReflectionMetadataBuilder {
   ArrayRef<std::pair<StringRef, CanType>> AssociatedTypes;
 
   void layout() override {
-    // If the conforming type is generic, we just want to emit the
-    // unbound generic type here.
-    auto *Nominal = Conformance->getType()->getAnyNominal();
-    assert(Nominal && "Structural conformance?");
+    PrettyStackTraceConformance DebugStack("emitting associated type metadata",
+                                           Conformance);
 
-    PrettyStackTraceDecl DebugStack("emitting associated type metadata",
-                                    Nominal);
-
-    addNominalRef(Nominal);
+    auto *DC = Conformance->getDeclContext();
+    addNominalRef(DC->getSelfNominalTypeDecl());
     addNominalRef(Conformance->getProtocol());
 
     B.addInt32(AssociatedTypes.size());
     B.addInt32(AssociatedTypeRecordSize);
 
+    auto genericSig = DC->getGenericSignatureOfContext().getCanonicalSignature();
     for (auto AssocTy : AssociatedTypes) {
       auto NameGlobal = IGM.getAddrOfFieldName(AssocTy.first);
       B.addRelativeAddress(NameGlobal);
-      addTypeRef(AssocTy.second,
-                 Nominal->getGenericSignature().getCanonicalSignature());
+      addTypeRef(AssocTy.second, genericSig);
     }
   }
 

lib/IRGen/IRGenMangler.cpp

@@ -144,8 +144,10 @@ IRGenMangler::withSymbolicReferences(IRGenModule &IGM,
 
 SymbolicMangling
 IRGenMangler::mangleTypeForReflection(IRGenModule &IGM,
-                                      Type Ty) {
+                                      CanGenericSignature Sig,
+                                      CanType Ty) {
   return withSymbolicReferences(IGM, [&]{
+    bindGenericParameters(Sig);
     appendType(Ty);
   });
 }
@@ -181,20 +183,6 @@ std::string IRGenMangler::mangleProtocolConformanceInstantiationCache(
   return finalize();
 }
 
-SymbolicMangling
-IRGenMangler::mangleProtocolConformanceForReflection(IRGenModule &IGM,
-                                  Type ty, ProtocolConformanceRef conformance) {
-  return withSymbolicReferences(IGM, [&]{
-    if (conformance.isConcrete()) {
-      appendProtocolConformance(conformance.getConcrete());
-    } else {
-      // Use a special mangling for abstract conformances.
-      appendType(ty);
-      appendProtocolName(conformance.getAbstract());
-    }
-  });
-}
-
 std::string IRGenMangler::mangleTypeForLLVMTypeName(CanType Ty) {
   // To make LLVM IR more readable we always add a 'T' prefix so that type names
   // don't start with a digit and don't need to be quoted.

lib/IRGen/IRGenMangler.h

@@ -483,6 +483,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedCopyFunction(CanType ty,
                                          CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(ty);
     if (sig)
       appendGenericSignature(sig);
@@ -492,6 +493,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedConsumeFunction(CanType ty,
                                             CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(ty);
     if (sig)
       appendGenericSignature(sig);
@@ -502,6 +504,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedRetainFunction(CanType t,
                                            CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(t);
     if (sig)
       appendGenericSignature(sig);
@@ -511,6 +514,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedReleaseFunction(CanType t,
                                             CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(t);
     if (sig)
       appendGenericSignature(sig);
@@ -521,6 +525,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedInitializeWithTakeFunction(CanType t,
                                                        CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(t);
     if (sig)
       appendGenericSignature(sig);
@@ -530,6 +535,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedInitializeWithCopyFunction(CanType t,
                                                        CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(t);
     if (sig)
       appendGenericSignature(sig);
@@ -539,6 +545,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedAssignWithTakeFunction(CanType t,
                                                    CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(t);
     if (sig)
       appendGenericSignature(sig);
@@ -548,6 +555,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedAssignWithCopyFunction(CanType t,
                                                    CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(t);
     if (sig)
       appendGenericSignature(sig);
@@ -557,6 +565,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   std::string mangleOutlinedDestroyFunction(CanType t,
                                             CanGenericSignature sig) {
     beginMangling();
+    bindGenericParameters(sig);
     appendType(t);
     if (sig)
       appendGenericSignature(sig);
@@ -571,11 +580,8 @@ class IRGenMangler : public Mangle::ASTMangler {
   }
 
   SymbolicMangling mangleTypeForReflection(IRGenModule &IGM,
-                                           Type Ty);
-  
-  SymbolicMangling mangleProtocolConformanceForReflection(IRGenModule &IGM,
-                                            Type Ty,
-                                            ProtocolConformanceRef conformance);
+                                           CanGenericSignature genericSig,
+                                           CanType Ty);
 
   std::string mangleTypeForLLVMTypeName(CanType Ty);
 

test/IRGen/Inputs/retroactive_conformance_other.swift

@@ -0,0 +1,6 @@
+public protocol P {}
+
+public enum E<First, Second> {
+  case left(First)
+  case right(Second)
+}

test/IRGen/retroactive_conformance.swift

@@ -0,0 +1,21 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module-path %t/retroactive_conformance_other.swiftmodule %S/Inputs/retroactive_conformance_other.swift
+// RUN: %target-swift-frontend -emit-ir %s -I %t
+
+import retroactive_conformance_other
+
+public struct Foo<T: P> {}
+
+public enum MyError : Error {
+  case a
+}
+
+extension E: P where First: P {
+}
+
+public enum Bar<T: P> {
+  case x(Foo<E<T, MyError>>)
+  case y
+}
+
+