Refactor DynamicReplacementAttr::create

Remove a dead overload and add an overload for lazy member loading

Author: CodaFi

include/swift/AST/Attr.h

@@ -52,6 +52,7 @@ class FuncDecl;
 class ClassDecl;
 class GenericFunctionType;
 class LazyConformanceLoader;
+class LazyMemberLoader;
 class PatternBindingInitializer;
 class TrailingWhereClause;
 
@@ -1010,18 +1011,31 @@ class DynamicReplacementAttr final
     : public DeclAttribute,
       private llvm::TrailingObjects<DynamicReplacementAttr, SourceLoc> {
   friend TrailingObjects;
+  friend class DynamicallyReplacedDeclRequest;
 
   DeclName ReplacedFunctionName;
-  AbstractFunctionDecl *ReplacedFunction;
+  LazyMemberLoader *Resolver = nullptr;
+  uint64_t ResolverContextData;
 
   /// Create an @_dynamicReplacement(for:) attribute written in the source.
   DynamicReplacementAttr(SourceLoc atLoc, SourceRange baseRange,
                          DeclName replacedFunctionName, SourceRange parenRange);
 
-  explicit DynamicReplacementAttr(DeclName name)
+  DynamicReplacementAttr(DeclName name, AbstractFunctionDecl *f)
       : DeclAttribute(DAK_DynamicReplacement, SourceLoc(), SourceRange(),
                       /*Implicit=*/false),
-        ReplacedFunctionName(name), ReplacedFunction(nullptr) {
+        ReplacedFunctionName(name),
+        Resolver(nullptr), ResolverContextData(0) {
+    Bits.DynamicReplacementAttr.HasTrailingLocationInfo = false;
+  }
+
+  DynamicReplacementAttr(DeclName name,
+                         LazyMemberLoader *Resolver = nullptr,
+                         uint64_t Data = 0)
+      : DeclAttribute(DAK_DynamicReplacement, SourceLoc(), SourceRange(),
+                      /*Implicit=*/false),
+        ReplacedFunctionName(name),
+        Resolver(Resolver), ResolverContextData(Data) {
     Bits.DynamicReplacementAttr.HasTrailingLocationInfo = false;
   }
 
@@ -1045,25 +1059,18 @@ class DynamicReplacementAttr final
          SourceLoc LParenLoc, DeclName replacedFunction, SourceLoc RParenLoc);
 
   static DynamicReplacementAttr *create(ASTContext &ctx,
-                                        DeclName replacedFunction);
+                                        DeclName replacedFunction,
+                                        AbstractFunctionDecl *replacedFuncDecl);
 
   static DynamicReplacementAttr *create(ASTContext &ctx,
                                         DeclName replacedFunction,
-                                        AbstractFunctionDecl *replacedFuncDecl);
+                                        LazyMemberLoader *Resolver,
+                                        uint64_t Data);
 
   DeclName getReplacedFunctionName() const {
     return ReplacedFunctionName;
   }
 
-  AbstractFunctionDecl *getReplacedFunction() const {
-    return ReplacedFunction;
-  }
-
-  void setReplacedFunction(AbstractFunctionDecl *f) {
-    assert(ReplacedFunction == nullptr);
-    ReplacedFunction = f;
-  }
-
   /// Retrieve the location of the opening parentheses, if there is one.
   SourceLoc getLParenLoc() const;
 

lib/AST/Attr.cpp

@@ -22,14 +22,14 @@
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/IndexSubset.h"
 #include "swift/AST/Module.h"
+#include "swift/AST/ParameterList.h"
 #include "swift/AST/TypeRepr.h"
 #include "swift/AST/Types.h"
-#include "swift/AST/ParameterList.h"
 #include "swift/Basic/Defer.h"
 #include "llvm/ADT/SmallString.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
 using namespace swift;
 
 #define DECL_ATTR(_, Id, ...) \
@@ -1148,7 +1148,7 @@ DynamicReplacementAttr::DynamicReplacementAttr(SourceLoc atLoc,
                                                SourceRange parenRange)
     : DeclAttribute(DAK_DynamicReplacement, atLoc, baseRange,
                     /*Implicit=*/false),
-      ReplacedFunctionName(name), ReplacedFunction(nullptr) {
+      ReplacedFunctionName(name) {
   Bits.DynamicReplacementAttr.HasTrailingLocationInfo = true;
   getTrailingLocations()[0] = parenRange.Start;
   getTrailingLocations()[1] = parenRange.End;
@@ -1165,17 +1165,16 @@ DynamicReplacementAttr::create(ASTContext &Ctx, SourceLoc AtLoc,
       SourceRange(LParenLoc, RParenLoc));
 }
 
-DynamicReplacementAttr *DynamicReplacementAttr::create(ASTContext &Ctx,
-                                                       DeclName name) {
-  return new (Ctx) DynamicReplacementAttr(name);
+DynamicReplacementAttr *
+DynamicReplacementAttr::create(ASTContext &Ctx, DeclName name,
+                               AbstractFunctionDecl *f) {
+  return new (Ctx) DynamicReplacementAttr(name, f);
 }
 
 DynamicReplacementAttr *
 DynamicReplacementAttr::create(ASTContext &Ctx, DeclName name,
-                               AbstractFunctionDecl *f) {
-  auto res = new (Ctx) DynamicReplacementAttr(name);
-  res->setReplacedFunction(f);
-  return res;
+                               LazyMemberLoader *Resolver, uint64_t Data) {
+  return new (Ctx) DynamicReplacementAttr(name, Resolver, Data);
 }
 
 SourceLoc DynamicReplacementAttr::getLParenLoc() const {