Simplify FindExternalVisibleDeclsByName by making it return a bool indicating

if it found any decls, rather than returning a list of found decls. This
removes a returning-ArrayRef-to-deleted-storage bug from
MultiplexExternalSemaSource (in code not exercised by any of the clang
binaries), reduces the work required in the found-no-decls case with PCH, and
importantly removes the need for DeclContext::lookup to be reentrant.

No functionality change intended!

llvm-svn: 174576

1 files changed, 3 insertions, 4 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index aa4c448e989..1213084e365 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -5424,14 +5424,13 @@ static ModuleFile *getDefinitiveModuleFileFor(const DeclContext *DC,
   return 0;
 }
 
-DeclContext::lookup_result
+bool
 ASTReader::FindExternalVisibleDeclsByName(const DeclContext *DC,
                                           DeclarationName Name) {
   assert(DC->hasExternalVisibleStorage() &&
          "DeclContext has no visible decls in storage");
   if (!Name)
-    return DeclContext::lookup_result(DeclContext::lookup_iterator(0),
-                                      DeclContext::lookup_iterator(0));
+    return false;
 
   SmallVector<NamedDecl *, 64> Decls;
   
@@ -5464,7 +5463,7 @@ ASTReader::FindExternalVisibleDeclsByName(const DeclContext *DC,
   }
   ++NumVisibleDeclContextsRead;
   SetExternalVisibleDeclsForName(DC, Name, Decls);
-  return const_cast<DeclContext*>(DC)->lookup(Name);
+  return !Decls.empty();
 }
 
 namespace {