[NFC] Refactor getRenameDecl to use the request evaluator

Move `getRenameDecl` from `PrintAsObjC` into its own request so that
other components can re-use this functionality.

Author: bnbarham

Diff for: include/swift/AST/Module.h

@@ -774,7 +774,6 @@ class ModuleDecl : public DeclContext, public TypeDecl {
   void collectBasicSourceFileInfo(
       llvm::function_ref<void(const BasicSourceFileInfo &)> callback) const;
 
-public:
   /// Retrieve a fingerprint value that summarizes the contents of this module.
   ///
   /// This interface hash a of a module is guaranteed to change if the interface
@@ -787,6 +786,15 @@ class ModuleDecl : public DeclContext, public TypeDecl {
   /// contents have been made.
   Fingerprint getFingerprint() const;
 
+  /// Returns an approximation of whether the given module could be
+  /// redistributed and consumed by external clients.
+  ///
+  /// FIXME: The scope of this computation should be limited entirely to
+  /// RenamedDeclRequest. Unfortunately, it has been co-opted to support the
+  /// \c SerializeOptionsForDebugging hack. Once this information can be
+  /// transferred from module files to the dSYMs, remove this.
+  bool isExternallyConsumed() const;
+
   SourceRange getSourceRange() const { return SourceRange(); }
 
   static bool classof(const DeclContext *DC) {

Diff for: include/swift/AST/TypeCheckRequests.h

@@ -3003,6 +3003,23 @@ class AsyncAlternativeRequest
   bool isCached() const { return true; }
 };
 
+class RenamedDeclRequest
+    : public SimpleRequest<RenamedDeclRequest,
+                           ValueDecl *(const ValueDecl *, const AvailableAttr *),
+                           RequestFlags::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  ValueDecl *evaluate(Evaluator &evaluator, const ValueDecl *attached,
+                      const AvailableAttr *attr) const;
+
+public:
+  bool isCached() const { return true; }
+};
+
 void simple_display(llvm::raw_ostream &out, Type value);
 void simple_display(llvm::raw_ostream &out, const TypeRepr *TyR);
 void simple_display(llvm::raw_ostream &out, ImplicitMemberAction action);

Diff for: include/swift/AST/TypeCheckerTypeIDZone.def

@@ -334,3 +334,6 @@ SWIFT_REQUEST(TypeChecker, GetImplicitSendableRequest,
 SWIFT_REQUEST(TypeChecker, AsyncAlternativeRequest,
               AbstractFunctionDecl *(AbstractFunctionDecl *),
               Cached, NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, RenamedDeclRequest,
+               ValueDecl *(const ValueDecl *),
+               Cached, NoLocationInfo)

Diff for: include/swift/Frontend/Frontend.h

@@ -403,15 +403,6 @@ class CompilerInvocation {
   SerializationOptions
   computeSerializationOptions(const SupplementaryOutputPaths &outs,
                               const ModuleDecl *module) const;
-
-  /// Returns an approximation of whether the given module could be
-  /// redistributed and consumed by external clients.
-  ///
-  /// FIXME: The scope of this computation should be limited entirely to
-  /// PrintAsObjC. Unfortunately, it has been co-opted to support the
-  /// \c SerializeOptionsForDebugging hack. Once this information can be
-  /// transferred from module files to the dSYMs, remove this.
-  bool isModuleExternallyConsumed(const ModuleDecl *mod) const;
 };
 
 /// A class which manages the state and execution of the compiler.

Diff for: include/swift/PrintAsObjC/PrintAsObjC.h

@@ -25,8 +25,7 @@ namespace swift {
   /// header.
   ///
   /// Returns true on error.
-  bool printAsObjC(raw_ostream &out, ModuleDecl *M, StringRef bridgingHeader,
-                   AccessLevel minRequiredAccess);
+  bool printAsObjC(raw_ostream &out, ModuleDecl *M, StringRef bridgingHeader);
 }
 
 #endif

Diff for: lib/AST/Module.cpp

@@ -1638,6 +1638,32 @@ Fingerprint ModuleDecl::getFingerprint() const {
   return Fingerprint{std::move(hasher)};
 }
 
+bool ModuleDecl::isExternallyConsumed() const {
+  // Modules for executables aren't expected to be consumed by other modules.
+  // This picks up all kinds of entrypoints, including script mode,
+  // @UIApplicationMain and @NSApplicationMain.
+  if (hasEntryPoint()) {
+    return false;
+  }
+
+  // If an implicit Objective-C header was needed to construct this module, it
+  // must be the product of a library target.
+  if (!getImplicitImportInfo().BridgingHeaderPath.empty()) {
+    return false;
+  }
+
+  // App extensions are special beasts because they build without entrypoints
+  // like library targets, but they behave like executable targets because
+  // their associated modules are not suitable for distribution.
+  if (getASTContext().LangOpts.EnableAppExtensionRestrictions) {
+    return false;
+  }
+
+  // FIXME: This is still a lousy approximation of whether the module file will
+  // be externally consumed.
+  return true;
+}
+
 //===----------------------------------------------------------------------===//
 // Cross-Import Overlays
 //===----------------------------------------------------------------------===//

Diff for: lib/Frontend/CompilerInvocation.cpp

@@ -2118,30 +2118,3 @@ CompilerInvocation::setUpInputForSILTool(
   }
   return fileBufOrErr;
 }
-
-bool CompilerInvocation::isModuleExternallyConsumed(
-    const ModuleDecl *mod) const {
-  // Modules for executables aren't expected to be consumed by other modules.
-  // This picks up all kinds of entrypoints, including script mode,
-  // @UIApplicationMain and @NSApplicationMain.
-  if (mod->hasEntryPoint()) {
-    return false;
-  }
-
-  // If an implicit Objective-C header was needed to construct this module, it
-  // must be the product of a library target.
-  if (!getFrontendOptions().ImplicitObjCHeaderPath.empty()) {
-    return false;
-  }
-
-  // App extensions are special beasts because they build without entrypoints
-  // like library targets, but they behave like executable targets because
-  // their associated modules are not suitable for distribution.
-  if (mod->getASTContext().LangOpts.EnableAppExtensionRestrictions) {
-    return false;
-  }
-
-  // FIXME: This is still a lousy approximation of whether the module file will
-  // be externally consumed.
-  return true;
-}

Diff for: lib/Frontend/Frontend.cpp

@@ -180,7 +180,7 @@ SerializationOptions CompilerInvocation::computeSerializationOptions(
   // the public.
   serializationOpts.SerializeOptionsForDebugging =
       opts.SerializeOptionsForDebugging.getValueOr(
-          !isModuleExternallyConsumed(module));
+          !module->isExternallyConsumed());
 
   serializationOpts.DisableCrossModuleIncrementalInfo =
       opts.DisableCrossModuleIncrementalBuild;

Diff for: lib/FrontendTool/FrontendTool.cpp

@@ -174,14 +174,12 @@ static bool writeSIL(SILModule &SM, const PrimarySpecificPaths &PSPs,
 ///
 /// \see swift::printAsObjC
 static bool printAsObjCIfNeeded(StringRef outputPath, ModuleDecl *M,
-                                StringRef bridgingHeader, bool moduleIsPublic) {
+                                StringRef bridgingHeader) {
   if (outputPath.empty())
     return false;
   return withOutputFile(M->getDiags(), outputPath,
                         [&](raw_ostream &out) -> bool {
-    auto requiredAccess = moduleIsPublic ? AccessLevel::Public
-                                         : AccessLevel::Internal;
-    return printAsObjC(out, M, bridgingHeader, requiredAccess);
+    return printAsObjC(out, M, bridgingHeader);
   });
 }
 
@@ -853,8 +851,7 @@ static bool emitAnyWholeModulePostTypeCheckSupplementaryOutputs(
     }
     hadAnyError |= printAsObjCIfNeeded(
         Invocation.getObjCHeaderOutputPathForAtMostOnePrimary(),
-        Instance.getMainModule(), BridgingHeaderPathForPrint,
-        Invocation.isModuleExternallyConsumed(Instance.getMainModule()));
+        Instance.getMainModule(), BridgingHeaderPathForPrint);
   }
 
   // Only want the header if there's been any errors, ie. there's not much

Diff for: lib/PrintAsObjC/DeclAndTypePrinter.cpp

@@ -23,6 +23,7 @@
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/PrettyStackTrace.h"
 #include "swift/AST/SwiftNameTranslation.h"
+#include "swift/AST/TypeCheckRequests.h"
 #include "swift/AST/TypeVisitor.h"
 #include "swift/IDE/CommentConversion.h"
 #include "swift/Parse/Lexer.h"
@@ -927,96 +928,15 @@ class DeclAndTypePrinter::Implementation
     return hasPrintedAnything;
   }
 
-  const ValueDecl *getRenameDecl(const ValueDecl *D,
-                                 const ParsedDeclName renamedParsedDeclName) {
-    auto declContext = D->getDeclContext();
-    ASTContext &astContext = D->getASTContext();
-    auto renamedDeclName = renamedParsedDeclName.formDeclNameRef(astContext);
-
-    if (isa<ClassDecl>(D) || isa<ProtocolDecl>(D)) {
-      if (!renamedParsedDeclName.ContextName.empty()) {
-        return nullptr;
-      }
-      SmallVector<ValueDecl *, 1> decls;
-      declContext->lookupQualified(declContext->getParentModule(),
-                                   renamedDeclName.withoutArgumentLabels(),
-                                   NL_OnlyTypes,
-                                   decls);
-      if (decls.size() == 1)
-        return decls[0];
-      return nullptr;
-    }
-
-    TypeDecl *typeDecl = declContext->getSelfNominalTypeDecl();
-
-    const ValueDecl *renamedDecl = nullptr;
-    SmallVector<ValueDecl *, 4> lookupResults;
-    declContext->lookupQualified(typeDecl->getDeclaredInterfaceType(),
-                                 renamedDeclName, NL_QualifiedDefault,
-                                 lookupResults);
-
-    if (lookupResults.size() == 1) {
-      auto candidate = lookupResults[0];
-      if (!shouldInclude(candidate))
-        return nullptr;
-      if (candidate->getKind() != D->getKind() ||
-          (candidate->isInstanceMember() !=
-           cast<ValueDecl>(D)->isInstanceMember()))
-        return nullptr;
-
-      renamedDecl = candidate;
-    } else {
-      for (auto candidate : lookupResults) {
-        if (!shouldInclude(candidate))
-          continue;
-
-        if (candidate->getKind() != D->getKind() ||
-            (candidate->isInstanceMember() !=
-             cast<ValueDecl>(D)->isInstanceMember()))
-          continue;
-
-        if (isa<AbstractFunctionDecl>(candidate)) {
-          auto cParams = cast<AbstractFunctionDecl>(candidate)->getParameters();
-          auto dParams = cast<AbstractFunctionDecl>(D)->getParameters();
-
-          if (cParams->size() != dParams->size())
-            continue;
-
-          bool hasSameParameterTypes = true;
-          for (auto index : indices(*cParams)) {
-            auto cParamsType = cParams->get(index)->getType();
-            auto dParamsType = dParams->get(index)->getType();
-            if (!cParamsType->matchesParameter(dParamsType,
-                                               TypeMatchOptions())) {
-              hasSameParameterTypes = false;
-              break;
-            }
-          }
-
-          if (!hasSameParameterTypes) {
-            continue;
-          }
-        }
-
-        if (renamedDecl) {
-          // If we found a duplicated candidate then we would silently fail.
-          renamedDecl = nullptr;
-          break;
-        }
-        renamedDecl = candidate;
-      }
-    }
-    return renamedDecl;
-  }
-
   void printRenameForDecl(const AvailableAttr *AvAttr, const ValueDecl *D,
                           bool includeQuotes) {
     assert(!AvAttr->Rename.empty());
 
-    const ValueDecl *renamedDecl =
-        getRenameDecl(D, parseDeclName(AvAttr->Rename));
-
+    auto *renamedDecl = evaluateOrDefault(
+        getASTContext().evaluator, RenamedDeclRequest{D, AvAttr}, nullptr);
     if (renamedDecl) {
+      assert(shouldInclude(renamedDecl) &&
+             "ObjC printer logic mismatch with renamed decl");
       SmallString<128> scratch;
       auto renamedObjCRuntimeName =
           renamedDecl->getObjCRuntimeName()->getString(scratch);

Diff for: lib/PrintAsObjC/ModuleContentsWriter.cpp

@@ -598,6 +598,8 @@ class ModuleWriter {
 void
 swift::printModuleContentsAsObjC(raw_ostream &os,
                                  llvm::SmallPtrSetImpl<ImportModuleTy> &imports,
-                                 ModuleDecl &M, AccessLevel minRequiredAccess) {
-  ModuleWriter(os, imports, M, minRequiredAccess).write();
+                                 ModuleDecl &M) {
+  auto requiredAccess = M.isExternallyConsumed() ? AccessLevel::Public
+                                                 : AccessLevel::Internal;
+  ModuleWriter(os, imports, M, requiredAccess).write();
 }

Diff for: lib/PrintAsObjC/ModuleContentsWriter.h

@@ -27,11 +27,11 @@ class ModuleDecl;
 
 using ImportModuleTy = PointerUnion<ModuleDecl*, const clang::Module*>;
 
-/// Prints the declarations of \p M to \p os, filtering by \p minRequiredAccess
-/// and collecting imports in \p imports along the way.
+/// Prints the declarations of \p M to \p os and collecting imports in
+/// \p imports along the way.
 void printModuleContentsAsObjC(raw_ostream &os,
                                llvm::SmallPtrSetImpl<ImportModuleTy> &imports,
-                               ModuleDecl &M, AccessLevel minRequiredAccess);
+                               ModuleDecl &M);
 
 } // end namespace swift
 

Diff for: lib/PrintAsObjC/PrintAsObjC.cpp

@@ -383,14 +383,13 @@ static void writeEpilogue(raw_ostream &os) {
 }
 
 bool swift::printAsObjC(raw_ostream &os, ModuleDecl *M,
-                        StringRef bridgingHeader,
-                        AccessLevel minRequiredAccess) {
+                        StringRef bridgingHeader) {
   llvm::PrettyStackTraceString trace("While generating Objective-C header");
 
   SmallPtrSet<ImportModuleTy, 8> imports;
   std::string moduleContentsBuf;
   llvm::raw_string_ostream moduleContents{moduleContentsBuf};
-  printModuleContentsAsObjC(moduleContents, imports, *M, minRequiredAccess);
+  printModuleContentsAsObjC(moduleContents, imports, *M);
   std::string macroGuard = (llvm::Twine(M->getNameStr().upper()) + "_SWIFT_H").str();
   writePrologue(os, M->getASTContext(), macroGuard);
   writeImports(os, imports, *M, bridgingHeader);