From 1f94124b76680211f3585ac8c3b24b247f46fac3 Mon Sep 17 00:00:00 2001
From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Fri, 21 Sep 2012 01:30:00 +0000
Subject: [PATCH] [PCH] After deserializing a DeclContext, if it has external
 lexical decls but not external visible decls, call
 DeclContext::setMustBuildLookupTable so that the "lazy decls" bit of the
 LookupPtr is set.

Previously, in non-C++, if there were no new declarations causing the "lazy decls" bit
to be set, then DeclContext::lookups_begin() would fail to return the decls from the PCH.

Fixes rdar://12316296.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164351 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Serialization/ASTReader.cpp          |  4 ++++
 lib/Serialization/ASTReaderDecl.cpp      |  3 +++
 test/Index/rdar12316296-codecompletion.m | 23 +++++++++++++++++++++++
 3 files changed, 30 insertions(+)
 create mode 100644 test/Index/rdar12316296-codecompletion.m

diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 478217bd03..9fe6ef317e 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -1661,6 +1661,10 @@ ASTReader::ReadASTBlock(ModuleFile &F) {
         return Failure;
       }
 
+      DeclContext *DC = Context.getTranslationUnitDecl();
+      if (!DC->hasExternalVisibleStorage() && DC->hasExternalLexicalStorage())
+        DC->setMustBuildLookupTable();
+
       return Success;
     }
 
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 754ff36db7..c9788a3216 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -2127,6 +2127,9 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
       }
       PendingVisibleUpdates.erase(I);
     }
+
+    if (!DC->hasExternalVisibleStorage() && DC->hasExternalLexicalStorage())
+      DC->setMustBuildLookupTable();
   }
   assert(Idx == Record.size());
 
diff --git a/test/Index/rdar12316296-codecompletion.m b/test/Index/rdar12316296-codecompletion.m
new file mode 100644
index 0000000000..f588a99837
--- /dev/null
+++ b/test/Index/rdar12316296-codecompletion.m
@@ -0,0 +1,23 @@
+// RUN: c-index-test -write-pch %t.h.pch %s
+// RUN: c-index-test -code-completion-at=%s:19:1 %s -include %t.h | FileCheck %s
+
+// <rdar://12316296> clang Code Completion returns nothing but preprocessor macros
+
+#ifndef HEADER
+#define HEADER
+
+@interface I
+@end
+
+// CHECK: FunctionDecl:{ResultType void}{TypedText foo}
+void foo();
+
+#else
+
+@implementation I
+-(void)meth {
+
+}
+@end
+
+#endif
-- 
2.40.0