Cope with anonymous tags defined within declarators by structurally

comparing their types under the assumption that they are equivalent,
rather than importing the types and then checking for compatibility. A
few minor tweaks here:
  - Teach structural matching to handle compatibility between
  function types with prototypes and those without prototypes.
  - Teach structural matching that an incomplete record decl is the
  same as any other record decl with the same name.
  - Keep track of pairs of declarations that we have already checked
  (but failed to find as structurally matching), so we don't emit
  diagnostics repeatedly.
  - When importing a typedef of an anonymous tag, be sure to link the
  imported tag type to its typedef.

With these changes, we survive a repeated import of <stdlib.h> and
<stdio.h>. Alas, the ASTNodeImporter is getting a little grotty.

llvm-svn: 96298

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/test/ASTMerge/Inputs/enum1.c b/clang/test/ASTMerge/Inputs/enum1.c
index cbbed47bacf..f2b9c5c98fd 100644
--- a/clang/test/ASTMerge/Inputs/enum1.c
+++ b/clang/test/ASTMerge/Inputs/enum1.c
@@ -32,3 +32,11 @@ enum E5 {
   E5Enumerator2,
   E5Enumerator3
 } x5;
+
+// Matching, with typedef
+typedef enum {
+  E6Enumerator1,
+  E6Enumerator2
+} E6;
+
+E6 x6;