[PATCH] FIx PR47647, revert an earlier patch

[Richard Guenther <rguenther@suse.de>]

This reverts lazy BLOCK_VARS streaming as I thought back in time
that VAR_DECLs have BLOCKs as DECL_CONTEXT while they have
FUNCTION_DECLs ... so the patch doesn't work at all and instead
causes us to not stream in any BLOCKs, resulting in no local
decls at all in debug info.  Not good.

Fixed with the following which also makes latent guality issues
re-appear - they were hidden by

pr41353-1.gdb:3: Error in sourced command file:^M
No symbol "vari2" in current context.^M
UNSUPPORTED: gcc.dg/guality/pr41353-1.c  -O2 -flto -flto-partition=none  
line 17 vari2 == 3 * 17

where "No symbol "vari2" in current context" isn't treated the
same as "<optimized out>" ...

I have filed bugs for some LTO debug info issues I noticed.

Bootstrapped and tested on x86_64-unknown-linux-gnu, ok?

Thanks,
Richard.

2011-02-18  Richard Guenther  <rguenther@suse.de>

	PR lto/47647
	* lto-streamer-in.c (lto_input_ts_decl_minimal_tree_pointers):
	Remove lazy BLOCK_VARS streaming.
	(lto_input_ts_block_tree_pointers): Likewise.
	* lto-streamer-out.c (lto_output_ts_block_tree_pointers): Likewise.

Index: trunk/gcc/lto-streamer-in.c
===================================================================
*** trunk.orig/gcc/lto-streamer-in.c	2011-02-18 15:15:52.000000000 +0100
--- trunk/gcc/lto-streamer-in.c	2011-02-18 16:19:25.000000000 +0100
*************** lto_input_ts_decl_minimal_tree_pointers
*** 1960,1972 ****
  {
    DECL_NAME (expr) = lto_input_tree (ib, data_in);
    DECL_CONTEXT (expr) = lto_input_tree (ib, data_in);
-   /* We do not stream BLOCK_VARS but lazily construct it here.  */
-   if (DECL_CONTEXT (expr)
-       && TREE_CODE (DECL_CONTEXT (expr)) == BLOCK)
-     {
-       TREE_CHAIN (expr) = BLOCK_VARS (DECL_CONTEXT (expr));
-       BLOCK_VARS (DECL_CONTEXT (expr)) = expr;
-     }
    DECL_SOURCE_LOCATION (expr) = lto_input_location (ib, data_in);
  }
  
--- 1960,1965 ----
*************** lto_input_ts_block_tree_pointers (struct
*** 2188,2195 ****
    unsigned i, len;
  
    BLOCK_SOURCE_LOCATION (expr) = lto_input_location (ib, data_in);
!   /* We do not stream BLOCK_VARS but lazily construct it when reading
!      in decls.  */
  
    len = lto_input_uleb128 (ib);
    if (len > 0)
--- 2181,2187 ----
    unsigned i, len;
  
    BLOCK_SOURCE_LOCATION (expr) = lto_input_location (ib, data_in);
!   BLOCK_VARS (expr) = lto_input_chain (ib, data_in);
  
    len = lto_input_uleb128 (ib);
    if (len > 0)
Index: trunk/gcc/lto-streamer-out.c
===================================================================
*** trunk.orig/gcc/lto-streamer-out.c	2011-02-18 15:15:50.000000000 +0100
--- trunk/gcc/lto-streamer-out.c	2011-02-18 16:13:13.000000000 +0100
*************** lto_output_ts_block_tree_pointers (struc
*** 1057,1064 ****
    tree t;
  
    lto_output_location (ob, BLOCK_SOURCE_LOCATION (expr));
!   /* We do not stream BLOCK_VARS but lazily construct it when reading
!      in decls.  */
  
    output_uleb128 (ob, VEC_length (tree, BLOCK_NONLOCALIZED_VARS (expr)));
    FOR_EACH_VEC_ELT (tree, BLOCK_NONLOCALIZED_VARS (expr), i, t)
--- 1057,1063 ----
    tree t;
  
    lto_output_location (ob, BLOCK_SOURCE_LOCATION (expr));
!   lto_output_chain (ob, BLOCK_VARS (expr), ref_p);
  
    output_uleb128 (ob, VEC_length (tree, BLOCK_NONLOCALIZED_VARS (expr)));
    FOR_EACH_VEC_ELT (tree, BLOCK_NONLOCALIZED_VARS (expr), i, t)