[RFC PATCH, LTO] Linked list of stmt uids->stmts fixup hooks

[Martin Jambor <mjambor at suse dot cz>]

Hi,

while working on streaming of indirect inlinining information I
need to turn gimple stmt uids into gimple statements in the same way
this is done for call graph edges.  

I can either call a function in ipa-prop.c doing this directly from
input_function() in lto-streamer-in.c or add some generic simplisitc
infrastructure like what is in the patch below.  I simply added a
linked list of hooks that I envision will consist of static
structures, one per running IPA pass that needs this.

Alternatively, running fixup_call_stmt_edges() after IPA decisions are
made (and inlining decisions in particular).  So far I assumed it was
called before in non-wpa mode on purpose.

The patch is untested.  What do you think about this approach?

Thanks,

Martin

2009-11-03  Martin Jambor  <mjambor@suse.cz>

	* lto-streamer.h (struct lto_stmt_fixup_hook_list_element): New type.
	(lto_stmt_fixup_hook_list) Declare.

	* lto-streamer-in.c (input_function): Call all stmt fixup hooks in
	lto_stmt_fixup_hook_list.
	(lto_stmt_fixup_hook_list) New variable.

Index: icln/gcc/lto-streamer-in.c
===================================================================
--- icln.orig/gcc/lto-streamer-in.c
+++ icln/gcc/lto-streamer-in.c
@@ -59,6 +59,9 @@ struct string_slot
 /* The table to hold the file names.  */
 static htab_t file_name_hash_table;
 
+/* Linked list of pointers to stmt uids -> stmts fixup functions.  */
+struct lto_stmt_fixup_hook_list_element *lto_stmt_fixup_hook_list;
+
 
 /* Check that tag ACTUAL has one of the given values.  NUM_TAGS is the
    number of valid tag values to check.  */
@@ -1261,6 +1264,9 @@ input_function (tree fn_decl, struct dat
   gimple *stmts;
   basic_block bb;
   struct bitpack_d *bp;
+  struct cgraph_node *node;
+  struct lto_stmt_fixup_hook_list_element *fixup_hook;
+
 
   fn = DECL_STRUCT_FUNCTION (fn_decl);
   tag = input_record_start (ib);
@@ -1340,7 +1346,12 @@ input_function (tree fn_decl, struct dat
     gimple_set_body (fn_decl, bb_seq (ei_edge (ei)->dest));
   }
 
-  fixup_call_stmt_edges (cgraph_node (fn_decl), stmts);
+  node = cgraph_node (fn_decl);
+  fixup_call_stmt_edges (node, stmts);
+  for (fixup_hook = lto_stmt_fixup_hook_list;
+       fixup_hook;
+       fixup_hook = fixup_hook->next)
+    fixup_hook->hook (node, stmts);
 
   update_ssa (TODO_update_ssa_only_virtuals); 
   free_dominance_info (CDI_DOMINATORS);
Index: icln/gcc/lto-streamer.h
===================================================================
--- icln.orig/gcc/lto-streamer.h
+++ icln/gcc/lto-streamer.h
@@ -689,6 +689,13 @@ struct data_in
   struct lto_streamer_cache_d *reader_cache;
 };
 
+/* Add-only linked list of functions that turn gimple statement uids into
+   gimple statements in IPA-pass info.  */
+struct lto_stmt_fixup_hook_list_element
+{
+  void (*hook)(struct cgraph_node *, gimple *);
+  struct lto_stmt_fixup_hook_list_element *next;
+};
 
 /* In lto-section-in.c  */
 extern struct lto_input_block * lto_create_simple_input_block (
@@ -803,6 +810,8 @@ extern void lto_check_version (int, int)
 
 
 /* In lto-streamer-in.c */
+extern struct lto_stmt_fixup_hook_list_element *lto_stmt_fixup_hook_list;
+
 extern void lto_input_cgraph (struct lto_file_decl_data *, const char *);
 extern void lto_init_reader (void);
 extern tree lto_input_tree (struct lto_input_block *, struct data_in *);