function_ref-ize ExternalASTSource::FindExternalLexicalDecl and remove its

useless return value. Switch to using it directly when completing the
redeclaration chain for an anonymous declaration, and reduce the set of
declarations that we load in the process to just those of the right kind.

llvm-svn: 244161

1 files changed, 30 insertions, 24 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 52231387ef2..abc91e771ec 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -5910,8 +5910,13 @@ void ASTReader::CompleteRedeclChain(const Decl *D) {
       } else
         DC->lookup(Name);
     } else if (needsAnonymousDeclarationNumber(cast<NamedDecl>(D))) {
-      // FIXME: It'd be nice to do something a bit more targeted here.
-      D->getDeclContext()->decls_begin();
+      // Find all declarations of this kind from the relevant context.
+      for (auto *DCDecl : cast<Decl>(D->getLexicalDeclContext())->redecls()) {
+        auto *DC = cast<DeclContext>(DCDecl);
+        SmallVector<Decl*, 8> Decls;
+        FindExternalLexicalDecls(
+            DC, [&](Decl::Kind K) { return K == D->getKind(); }, Decls);
+      }
     }
   }
 
@@ -6174,47 +6179,48 @@ namespace {
   class FindExternalLexicalDeclsVisitor {
     ASTReader &Reader;
     const DeclContext *DC;
-    bool (*isKindWeWant)(Decl::Kind);
+    llvm::function_ref<bool(Decl::Kind)> IsKindWeWant;
     
     SmallVectorImpl<Decl*> &Decls;
     bool PredefsVisited[NUM_PREDEF_DECL_IDS];
 
   public:
-    FindExternalLexicalDeclsVisitor(ASTReader &Reader, const DeclContext *DC,
-                                    bool (*isKindWeWant)(Decl::Kind),
-                                    SmallVectorImpl<Decl*> &Decls)
-      : Reader(Reader), DC(DC), isKindWeWant(isKindWeWant), Decls(Decls) 
-    {
+    FindExternalLexicalDeclsVisitor(
+        ASTReader &Reader, const DeclContext *DC,
+        llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
+        SmallVectorImpl<Decl *> &Decls)
+        : Reader(Reader), DC(DC), IsKindWeWant(IsKindWeWant), Decls(Decls) {
       for (unsigned I = 0; I != NUM_PREDEF_DECL_IDS; ++I)
         PredefsVisited[I] = false;
     }
 
     static bool visitPostorder(ModuleFile &M, void *UserData) {
-      FindExternalLexicalDeclsVisitor *This
-        = static_cast<FindExternalLexicalDeclsVisitor *>(UserData);
+      return (*static_cast<FindExternalLexicalDeclsVisitor*>(UserData))(M);
+    }
 
-      ModuleFile::DeclContextInfosMap::iterator Info
-        = M.DeclContextInfos.find(This->DC);
+    bool operator()(ModuleFile &M) {
+      ModuleFile::DeclContextInfosMap::iterator Info =
+          M.DeclContextInfos.find(DC);
       if (Info == M.DeclContextInfos.end() || Info->second.LexicalDecls.empty())
         return false;
 
       // Load all of the declaration IDs
       for (const KindDeclIDPair &P : Info->second.LexicalDecls) {
-        if (This->isKindWeWant && !This->isKindWeWant((Decl::Kind)P.first))
+        if (!IsKindWeWant((Decl::Kind)P.first))
           continue;
 
         // Don't add predefined declarations to the lexical context more
         // than once.
         if (P.second < NUM_PREDEF_DECL_IDS) {
-          if (This->PredefsVisited[P.second])
+          if (PredefsVisited[P.second])
             continue;
 
-          This->PredefsVisited[P.second] = true;
+          PredefsVisited[P.second] = true;
         }
 
-        if (Decl *D = This->Reader.GetLocalDecl(M, P.second)) {
-          if (!This->DC->isDeclInLexicalTraversal(D))
-            This->Decls.push_back(D);
+        if (Decl *D = Reader.GetLocalDecl(M, P.second)) {
+          if (!DC->isDeclInLexicalTraversal(D))
+            Decls.push_back(D);
         }
       }
 
@@ -6223,16 +6229,16 @@ namespace {
   };
 }
 
-ExternalLoadResult ASTReader::FindExternalLexicalDecls(const DeclContext *DC,
-                                         bool (*isKindWeWant)(Decl::Kind),
-                                         SmallVectorImpl<Decl*> &Decls) {
+void ASTReader::FindExternalLexicalDecls(
+    const DeclContext *DC, llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
+    SmallVectorImpl<Decl *> &Decls) {
   // There might be lexical decls in multiple modules, for the TU at
-  // least. Walk all of the modules in the order they were loaded.
-  FindExternalLexicalDeclsVisitor Visitor(*this, DC, isKindWeWant, Decls);
+  // least. FIXME: Only look in multiple module files in the very rare
+  // cases where this can actually happen.
+  FindExternalLexicalDeclsVisitor Visitor(*this, DC, IsKindWeWant, Decls);
   ModuleMgr.visitDepthFirst(
       nullptr, &FindExternalLexicalDeclsVisitor::visitPostorder, &Visitor);
   ++NumLexicalDeclContextsRead;
-  return ELR_Success;
 }
 
 namespace {