Add Qualified Lookup Requests

include/swift/AST/Module.h

@@ -629,6 +629,11 @@ inline bool DeclContext::isModuleScopeContext() const {
   return isModuleContext();
 }
 
+/// Extract the source location from the given module declaration.
+inline SourceLoc extractNearestSourceLoc(const ModuleDecl *mod) {
+  return extractNearestSourceLoc(static_cast<const Decl *>(mod));
+}
+
 } // end namespace swift
 
 namespace llvm {

include/swift/AST/NameLookupRequests.h

@@ -405,6 +405,45 @@ class AnyObjectLookupRequest
                                                  NLOptions options) const;
 };
 
+class ModuleQualifiedLookupRequest
+    : public SimpleRequest<ModuleQualifiedLookupRequest,
+                           QualifiedLookupResult(const DeclContext *,
+                                                 ModuleDecl *, DeclNameRef,
+                                                 NLOptions),
+                           CacheKind::Uncached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<QualifiedLookupResult> evaluate(Evaluator &evaluator,
+                                                 const DeclContext *DC,
+                                                 ModuleDecl *mod, DeclNameRef name,
+                                                 NLOptions opts) const;
+};
+
+class QualifiedLookupRequest
+    : public SimpleRequest<QualifiedLookupRequest,
+                           QualifiedLookupResult(const DeclContext *,
+                                                 SmallVector<NominalTypeDecl *, 4>,
+                                                 DeclNameRef, NLOptions),
+                           CacheKind::Uncached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<QualifiedLookupResult>
+  evaluate(Evaluator &evaluator, const DeclContext *DC,
+           SmallVector<NominalTypeDecl *, 4> decls,
+           DeclNameRef name,
+           NLOptions opts) const;
+};
+
 #define SWIFT_TYPEID_ZONE NameLookup
 #define SWIFT_TYPEID_HEADER "swift/AST/NameLookupTypeIDZone.def"
 #include "swift/Basic/DefineTypeIDZone.h"

include/swift/AST/NameLookupTypeIDZone.def

@@ -15,6 +15,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+SWIFT_REQUEST(NameLookup, AnyObjectLookupRequest,
+              QualifiedLookupResult(const DeclContext *, DeclName, NLOptions),
+              Uncached, NoLocationInfo)
 SWIFT_REQUEST(NameLookup, CustomAttrNominalRequest,
               NominalTypeDecl *(CustomAttr *, DeclContext *), Cached,
               NoLocationInfo)
@@ -34,6 +37,20 @@ SWIFT_REQUEST(NameLookup, InheritedDeclsReferencedRequest,
               DirectlyReferencedTypeDecls(
                   llvm::PointerUnion<TypeDecl *, ExtensionDecl *>, unsigned),
               Uncached, HasNearestLocation)
+SWIFT_REQUEST(NameLookup, LookupInModuleRequest,
+              QualifiedLookupResult(const DeclContext *, DeclName, NLKind,
+                                    namelookup::ResolutionKind,
+                                    const DeclContext *),
+              Uncached, NoLocationInfo)
+SWIFT_REQUEST(NameLookup, ModuleQualifiedLookupRequest,
+              QualifiedLookupResult(
+                  const DeclContext *, ModuleDecl *, DeclNameRef, NLOptions),
+              Uncached, NoLocationInfo)
+SWIFT_REQUEST(NameLookup, QualifiedLookupRequest,
+              QualifiedLookupResult(
+                  const DeclContext *, SmallVector<NominalTypeDecl *, 4>,
+                  DeclNameRef, NLOptions),
+              Uncached, NoLocationInfo)
 SWIFT_REQUEST(NameLookup, SelfBoundsFromWhereClauseRequest,
               SelfBounds(llvm::PointerUnion<TypeDecl *, ExtensionDecl *>),
               Uncached, NoLocationInfo)
@@ -48,11 +65,3 @@ SWIFT_REQUEST(NameLookup, UnderlyingTypeDeclsReferencedRequest,
 SWIFT_REQUEST(NameLookup, UnqualifiedLookupRequest,
               LookupResult(UnqualifiedLookupDescriptor), Uncached,
               NoLocationInfo)
-SWIFT_REQUEST(NameLookup, LookupInModuleRequest,
-              QualifiedLookupResult(const DeclContext *, DeclName, NLKind,
-                                    namelookup::ResolutionKind,
-                                    const DeclContext *),
-              Uncached, NoLocationInfo)
-SWIFT_REQUEST(NameLookup, AnyObjectLookupRequest,
-              QualifiedLookupResult(const DeclContext *, DeclName, NLOptions),
-              Uncached, NoLocationInfo)

include/swift/Basic/Statistics.def

@@ -138,12 +138,6 @@ FRONTEND_STATISTIC(AST, NumPrefixOperators)
 /// Number of precedence groups in the AST context.
 FRONTEND_STATISTIC(AST, NumPrecedenceGroups)
 
-/// Number of qualified lookups into a nominal type.
-FRONTEND_STATISTIC(AST, NumLookupQualifiedInNominal)
-
-/// Number of qualified lookups into a module.
-FRONTEND_STATISTIC(AST, NumLookupQualifiedInModule)
-
 /// Number of local lookups into a module.
 FRONTEND_STATISTIC(AST, NumModuleLookupValue)
 

lib/AST/NameLookup.cpp

@@ -1587,17 +1587,24 @@ bool DeclContext::lookupQualified(ArrayRef<NominalTypeDecl *> typeDecls,
                                   DeclNameRef member,
                                   NLOptions options,
                                   SmallVectorImpl<ValueDecl *> &decls) const {
-  using namespace namelookup;
   assert(decls.empty() && "additive lookup not supported");
+  QualifiedLookupRequest req{this, {typeDecls.begin(), typeDecls.end()},
+                             member, options};
+  decls = evaluateOrDefault(getASTContext().evaluator, req, {});
+  return !decls.empty();
+}
 
-  auto *stats = getASTContext().Stats;
-  if (stats)
-    stats->getFrontendCounters().NumLookupQualifiedInNominal++;
+llvm::Expected<QualifiedLookupResult>
+QualifiedLookupRequest::evaluate(Evaluator &eval, const DeclContext *DC,
+                                 SmallVector<NominalTypeDecl *, 4> typeDecls,
+                                 DeclNameRef member, NLOptions options) const {
+  using namespace namelookup;
+  QualifiedLookupResult decls;
 
   // Configure lookup and dig out the tracker.
   ReferencedNameTracker *tracker = nullptr;
   bool isLookupCascading;
-  configureLookup(this, options, tracker, isLookupCascading);
+  configureLookup(DC, options, tracker, isLookupCascading);
 
   // Tracking for the nominal types we'll visit.
   SmallVector<NominalTypeDecl *, 4> stack;
@@ -1645,8 +1652,7 @@ bool DeclContext::lookupQualified(ArrayRef<NominalTypeDecl *> typeDecls,
       if ((options & NL_OnlyTypes) && !isa<TypeDecl>(decl))
         continue;
 
-      if (isAcceptableLookupResult(this, options, decl,
-                                   onlyCompleteObjectInits))
+      if (isAcceptableLookupResult(DC, options, decl, onlyCompleteObjectInits))
         decls.push_back(decl);
     }
 
@@ -1706,34 +1712,40 @@ bool DeclContext::lookupQualified(ArrayRef<NominalTypeDecl *> typeDecls,
     }
   }
 
-  pruneLookupResultSet(this, options, decls);
-  if (auto *debugClient = this->getParentModule()->getDebugClient()) {
-    debugClient->finishLookupInNominals(this, typeDecls, member.getFullName(),
+  pruneLookupResultSet(DC, options, decls);
+  if (auto *debugClient = DC->getParentModule()->getDebugClient()) {
+    debugClient->finishLookupInNominals(DC, typeDecls, member.getFullName(),
                                         options, decls);
   }
-  // We're done. Report success/failure.
-  return !decls.empty();
+
+  return decls;
 }
 
 bool DeclContext::lookupQualified(ModuleDecl *module, DeclNameRef member,
                                   NLOptions options,
                                   SmallVectorImpl<ValueDecl *> &decls) const {
-  using namespace namelookup;
+  assert(decls.empty() && "additive lookup not supported");
+  ModuleQualifiedLookupRequest req{this, module, member, options};
+  decls = evaluateOrDefault(getASTContext().evaluator, req, {});
+  return !decls.empty();
+}
 
-  auto &ctx = getASTContext();
-  auto *stats = ctx.Stats;
-  if (stats)
-    stats->getFrontendCounters().NumLookupQualifiedInModule++;
+llvm::Expected<QualifiedLookupResult>
+ModuleQualifiedLookupRequest::evaluate(Evaluator &eval, const DeclContext *DC,
+                                       ModuleDecl *module, DeclNameRef member,
+                                       NLOptions options) const {
+  using namespace namelookup;
+  QualifiedLookupResult decls;
 
   // Configure lookup and dig out the tracker.
   ReferencedNameTracker *tracker = nullptr;
   bool isLookupCascading;
-  configureLookup(this, options, tracker, isLookupCascading);
+  configureLookup(DC, options, tracker, isLookupCascading);
 
   auto kind = (options & NL_OnlyTypes
                ? ResolutionKind::TypesOnly
                : ResolutionKind::Overloadable);
-  auto topLevelScope = getModuleScopeContext();
+  auto topLevelScope = DC->getModuleScopeContext();
   if (module == topLevelScope->getParentModule()) {
     if (tracker) {
       recordLookupOfTopLevelName(topLevelScope, member.getFullName(),
@@ -1748,6 +1760,7 @@ bool DeclContext::lookupQualified(ModuleDecl *module, DeclNameRef member,
     // anything in this one.
 
     // Perform the lookup in all imports of this module.
+    auto &ctx = DC->getASTContext();
     auto accessPaths = ctx.getImportCache().getAllVisibleAccessPaths(
         module, topLevelScope);
     if (llvm::any_of(accessPaths,
@@ -1760,14 +1773,14 @@ bool DeclContext::lookupQualified(ModuleDecl *module, DeclNameRef member,
     }
   }
 
-  pruneLookupResultSet(this, options, decls);
+  pruneLookupResultSet(DC, options, decls);
 
-  if (auto *debugClient = this->getParentModule()->getDebugClient()) {
-    debugClient->finishLookupInModule(this, module, member.getFullName(),
+  if (auto *debugClient = DC->getParentModule()->getDebugClient()) {
+    debugClient->finishLookupInModule(DC, module, member.getFullName(),
                                       options, decls);
   }
-  // We're done. Report success/failure.
-  return !decls.empty();
+
+  return decls;
 }
 
 llvm::Expected<QualifiedLookupResult>
@@ -1997,7 +2010,9 @@ directReferencesForQualifiedTypeLookup(Evaluator &evaluator,
       auto innerOptions = options;
       innerOptions &= ~NL_RemoveOverridden;
       innerOptions &= ~NL_RemoveNonVisible;
-      dc->lookupQualified(module, name, innerOptions, members);
+      SmallVector<ValueDecl *, 4> moduleMembers;
+      dc->lookupQualified(module, name, innerOptions, moduleMembers);
+      members.append(moduleMembers.begin(), moduleMembers.end());
     }
 
     addResults(members);

test/decl/circularity.swift

@@ -96,7 +96,7 @@ class C4 {
   required init(x: Int) {}
 }
 
-class D4 : C4, P1 { // expected-note {{through reference here}}
+class D4 : C4, P1 { // expected-note 2 {{through reference here}}
   required init(x: X) { // expected-error {{circular reference}}
     // expected-note@-1 2{{through reference here}}
     super.init(x: x)

test/decl/class/circular_inheritance.swift

@@ -8,12 +8,12 @@
 // Check that we produced superclass type requests.
 // RUN: %{python} %utils/process-stats-dir.py --evaluate 'SuperclassTypeRequest == 18' %t/stats-dir
 
-class Left // expected-error {{circular reference}}
+class Left // expected-error {{circular reference}} expected-note {{through reference here}}
     : Right.Hand { // expected-note {{through reference here}}
   class Hand {}
 }
 
-class Right // expected-note {{through reference here}}
+class Right // expected-note 2 {{through reference here}}
   : Left.Hand { // expected-note {{through reference here}}
   class Hand {}
 }
@@ -35,13 +35,13 @@ class Outer {
   class Inner : Outer {}
 }
 
-class Outer2 // expected-error {{circular reference}}
+class Outer2 // expected-error {{circular reference}} expected-note {{through reference here}}
     : Outer2.Inner { // expected-note {{through reference here}}
 
   class Inner {}
 }
 
-class Outer3 // expected-error {{circular reference}}
+class Outer3 // expected-error {{circular reference}} expected-note {{through reference here}}
     : Outer3.Inner<Int> { // expected-note {{through reference here}}
   class Inner<T> {}
 }
@@ -79,6 +79,7 @@ class WithDesignatedInit : WithDesignatedInit {
   // expected-error@-1 {{'WithDesignatedInit' inherits from itself}}
   // expected-error@-2 {{circular reference}}
   // expected-note@-3 {{through reference here}}
+  // expected-note@-4 2 {{through reference here}}
 
   init(x: Int) {} // expected-error {{circular reference}}
 }