In the pph file, save and restore DECL_INITIAL instead of just PARM_DECL DECL_ARG_TYPE.
Index: gcc/cp/ChangeLog.pph 2011-04-29 Lawrence Crowl <cr...@google.com> * pph-streamer-out.c (pph_stream_write_tree): Write DECL_INITIAL instead of PARM_DECL DECL_ARG_TYPE. * pph-streamer-in.c (pph_stream_read_tree): Read DECL_INITIAL instead of PARM_DECL DECL_ARG_TYPE. Index: gcc/cp/pph-streamer-in.c =================================================================== --- gcc/cp/pph-streamer-in.c (revision 173189) +++ gcc/cp/pph-streamer-in.c (working copy) @@ -783,6 +783,8 @@ pph_stream_read_tree (struct lto_input_b if (DECL_P (expr)) { + DECL_INITIAL (expr) = pph_input_tree (stream); + if (TREE_CODE (expr) == FUNCTION_DECL || TREE_CODE (expr) == NAMESPACE_DECL || TREE_CODE (expr) == PARM_DECL @@ -791,8 +793,6 @@ pph_stream_read_tree (struct lto_input_b pph_stream_read_lang_specific (stream, expr); if (TREE_CODE (expr) == FUNCTION_DECL) DECL_SAVED_TREE (expr) = pph_input_tree (stream); - else if (TREE_CODE (expr) == PARM_DECL) - DECL_ARG_TYPE (expr) = pph_input_tree (stream); } if (TREE_CODE (expr) == TYPE_DECL) Index: gcc/cp/pph-streamer-out.c =================================================================== --- gcc/cp/pph-streamer-out.c (revision 173189) +++ gcc/cp/pph-streamer-out.c (working copy) @@ -787,6 +787,8 @@ pph_stream_write_tree (struct output_blo if (DECL_P (expr)) { + pph_output_tree_or_ref_1 (stream, DECL_INITIAL (expr), ref_p, 3); + if (TREE_CODE (expr) == FUNCTION_DECL || TREE_CODE (expr) == NAMESPACE_DECL || TREE_CODE (expr) == PARM_DECL @@ -796,8 +798,6 @@ pph_stream_write_tree (struct output_blo if (TREE_CODE (expr) == FUNCTION_DECL) pph_output_tree_or_ref_1 (stream, DECL_SAVED_TREE (expr), ref_p, 3); - else if (TREE_CODE (expr) == PARM_DECL) - pph_output_tree_or_ref_1 (stream, DECL_ARG_TYPE (expr), ref_p, 3); } if (TREE_CODE (expr) == TYPE_DECL) -- This patch is available for review at http://codereview.appspot.com/4442102