Support C++ friend declarations for PCH.

This commit 'introduces' a slightly different way to restore the state of the AST object.
It makes PCHDeclReader/PCHDeclWriter friends and gives them access to the private members of the object.
The rationale is to avoid using/modifying the AST interfaces for PCH read/write so that to:

-Avoid complications with objects that have side-effects during creation or when using some setters.
-Not 'pollute' the AST interface with methods only used by the PCH reader/writer
-Allow AST objects to be read-only.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107219 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 5 deletions

diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 8b714386c1..d947f7250d 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -1444,11 +1444,16 @@ uint64_t PCHWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
   if (DC->getPrimaryContext() != DC)
     return 0;
 
-  // Since there is no name lookup into functions or methods, and we
-  // perform name lookup for the translation unit via the
-  // IdentifierInfo chains, don't bother to build a
-  // visible-declarations table for these entities.
-  if (DC->isFunctionOrMethod() || DC->isTranslationUnit())
+  // Since there is no name lookup into functions or methods, don't bother to
+  // build a visible-declarations table for these entities.
+  if (DC->isFunctionOrMethod())
+    return 0;
+
+  // If not in C++, we perform name lookup for the translation unit via the
+  // IdentifierInfo chains, don't bother to build a visible-declarations table.
+  // FIXME: In C++ we need the visible declarations in order to "see" the
+  // friend declarations, is there a way to do this without writing the table ?
+  if (DC->isTranslationUnit() && !Context.getLangOptions().CPlusPlus)
     return 0;
 
   // Force the DeclContext to build a its name-lookup table.