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, 6 insertions, 0 deletions

diff --git a/clang/test/ASTMerge/Inputs/struct2.c b/clang/test/ASTMerge/Inputs/struct2.c
index 402283137ac..4b43df71d8d 100644
--- a/clang/test/ASTMerge/Inputs/struct2.c
+++ b/clang/test/ASTMerge/Inputs/struct2.c
@@ -52,3 +52,9 @@ struct DeepError {
   int value;
   struct DeeperError { int i; float f; } *Deeper;
 } xDeep;
+
+// Matches
+struct {
+  int i;
+  float f;
+} x11;