SILParser: Fix for removal of parse-time name lookup

include/swift/AST/Decl.h

@@ -1332,6 +1332,12 @@ class GenericParamList final :
 
   void print(raw_ostream &OS) const;
   SWIFT_DEBUG_DUMP;
+
+  bool walk(ASTWalker &walker);
+
+  /// Finds a generic parameter declaration by name. This should only
+  /// be used from the SIL parser.
+  GenericTypeParamDecl *lookUpGenericParam(Identifier name) const;
 };
 
 /// A trailing where clause.

include/swift/AST/TypeCheckRequests.h

@@ -2501,7 +2501,8 @@ class HasImplementationOnlyImportsRequest
 
 class ResolveTypeRequest
     : public SimpleRequest<ResolveTypeRequest,
-                           Type(const TypeResolution *, TypeRepr *),
+                           Type(const TypeResolution *, TypeRepr *,
+                                GenericParamList *),
                            RequestFlags::Uncached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -2515,7 +2516,7 @@ class ResolveTypeRequest
 
   // Evaluation.
   Type evaluate(Evaluator &evaluator, const TypeResolution *resolution,
-                TypeRepr *repr) const;
+                TypeRepr *repr, GenericParamList *silParams) const;
 };
 
 void simple_display(llvm::raw_ostream &out, const TypeResolution *resolution);

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -243,7 +243,7 @@ SWIFT_REQUEST(TypeChecker, ResolveTypeEraserTypeRequest,
               Type(ProtocolDecl *, TypeEraserAttr *),
               SeparatelyCached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ResolveTypeRequest,
-              Type (const TypeResolution *, TypeRepr *),
+              Type (const TypeResolution *, TypeRepr *, GenericParamList *),
               Uncached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, SPIGroupsRequest,
               llvm::ArrayRef<Identifier>(Decl *),

include/swift/Subsystems.h

@@ -149,7 +149,9 @@ namespace swift {
   ///
   /// \returns A well-formed type on success, or an \c ErrorType.
   Type performTypeResolution(TypeRepr *TyR, ASTContext &Ctx, bool isSILMode,
-                             bool isSILType, GenericEnvironment *GenericEnv,
+                             bool isSILType,
+                             GenericEnvironment *GenericEnv,
+                             GenericParamList *GenericParams,
                              DeclContext *DC, bool ProduceDiagnostics = true);
 
   /// Expose TypeChecker's handling of GenericParamList to SIL parsing.

lib/AST/ASTWalker.cpp

@@ -130,7 +130,7 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
     // Must check this first in case extensions have not been bound yet
     if (Walker.shouldWalkIntoGenericParams()) {
       if (auto *params = GC->getParsedGenericParams()) {
-        visitGenericParamList(params);
+        doIt(params);
       }
       return true;
     }
@@ -252,7 +252,7 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
 
   bool visitOpaqueTypeDecl(OpaqueTypeDecl *OTD) {
     if (Walker.shouldWalkIntoGenericParams() && OTD->getGenericParams()) {
-      if (visitGenericParamList(OTD->getGenericParams()))
+      if (doIt(OTD->getGenericParams()))
         return true;
     }
     return false;
@@ -439,22 +439,6 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
     return false;
   }
 
-  bool visitGenericParamList(GenericParamList *GPL) {
-    // Visit generic params
-    for (auto &P : GPL->getParams()) {
-      if (doIt(P))
-        return true;
-    }
-
-    // Visit param conformance
-    for (auto Req : GPL->getRequirements()) {
-      if (doIt(Req))
-        return true;
-    }
-
-    return false;
-  }
-
   //===--------------------------------------------------------------------===//
   //                                  Exprs
   //===--------------------------------------------------------------------===//
@@ -1342,12 +1326,28 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
         return true;
       break;
     case RequirementReprKind::LayoutConstraint:
-      if (doIt(Req.getFirstTypeRepr()))
+      if (doIt(Req.getSubjectRepr()))
         return true;
       break;
     }
     return false;
   }
+
+  bool doIt(GenericParamList *GPL) {
+    // Visit generic params
+    for (auto &P : GPL->getParams()) {
+      if (doIt(P))
+        return true;
+    }
+
+    // Visit param conformance
+    for (auto Req : GPL->getRequirements()) {
+      if (doIt(Req))
+        return true;
+    }
+
+    return false;
+  }
 };
 
 } // end anonymous namespace
@@ -1877,3 +1877,7 @@ StmtConditionElement *StmtConditionElement::walk(ASTWalker &walker) {
 bool Decl::walk(ASTWalker &walker) {
   return Traversal(walker).doIt(this);
 }
+
+bool GenericParamList::walk(ASTWalker &walker) {
+  return Traversal(walker).doIt(this);
+}

lib/AST/Decl.cpp

@@ -960,6 +960,21 @@ void GenericParamList::setDeclContext(DeclContext *dc) {
     param->setDeclContext(dc);
 }
 
+GenericTypeParamDecl *GenericParamList::lookUpGenericParam(
+    Identifier name) const {
+  for (const auto *innerParams = this;
+       innerParams != nullptr;
+       innerParams = innerParams->getOuterParameters()) {
+    for (auto *paramDecl : *innerParams) {
+      if (name == paramDecl->getName()) {
+        return const_cast<GenericTypeParamDecl *>(paramDecl);
+      }
+    }
+  }
+
+  return nullptr;
+}
+
 TrailingWhereClause::TrailingWhereClause(
                        SourceLoc whereLoc,
                        ArrayRef<RequirementRepr> requirements)

lib/IDE/CodeCompletion.cpp

@@ -1617,7 +1617,9 @@ class CodeCompletionCallbacksImpl : public CodeCompletionCallbacks {
     const auto ty = swift::performTypeResolution(
         ParsedTypeLoc.getTypeRepr(), P.Context,
         /*isSILMode=*/false,
-        /*isSILType=*/false, CurDeclContext->getGenericEnvironmentOfContext(),
+        /*isSILType=*/false,
+        CurDeclContext->getGenericEnvironmentOfContext(),
+        /*GenericParams=*/nullptr,
         CurDeclContext,
         /*ProduceDiagnostics=*/false);
     ParsedTypeLoc.setType(ty);

lib/IDE/ExprContextAnalysis.cpp

@@ -336,7 +336,7 @@ void swift::ide::collectPossibleReturnTypesFromContext(
           const auto type = swift::performTypeResolution(
               CE->getExplicitResultTypeRepr(), DC->getASTContext(),
               /*isSILMode=*/false, /*isSILType=*/false,
-              DC->getGenericEnvironmentOfContext(),
+              DC->getGenericEnvironmentOfContext(), /*GenericParams=*/nullptr,
               const_cast<DeclContext *>(DC), /*diagnostics=*/false);
 
           if (!type->hasError()) {