From patchwork Mon Jun 21 16:03:48 2010
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Subject: Fix bug with noreturn call
Date: Mon, 21 Jun 2010 06:03:48 -0000
From: Eric Botcazou <ebotcazou@adacore.com>
X-Patchwork-Id: 56330
Message-Id: <201006211803.49205.ebotcazou@adacore.com>
To: gcc-patches@gcc.gnu.org

Hi,

with our 4.5-based compiler, ACATS cxh1001 ICEs at -O2 -flto because of a 
dangling GIMPLE_CALL statement on the MODIFIED_NORETURN_CALLS list: the 
statement is replaced in cgraph_redirect_edge_call_stmt_to_callee but it 
nevertheless remains on the list.  Moveover the new statement doesn't inherit 
the noreturn property.

Fixed by clearing the BB.  The patch also removes a superfluous call to 
maybe_clean_or_replace_eh_stmt (gsi_replace already calls it) and makes sure 
that all the flags are copied in gimple_call_copy_skip_args.

Tested on x86_64-suse-linux.  OK for mainline (and 4.5 branch)?


2010-06-21  Eric Botcazou  <ebotcazou@adacore.com>

	* cgraphunit.c (cgraph_redirect_edge_call_stmt_to_callee): Chain the
	new statement only if necessary and clear its BB.  Remove superfluous
	call to maybe_clean_or_replace_eh_stmt.
	* gimple.c (gimple_call_copy_skip_args): Use gimple_call_copy_flags to
	copy the flags.


Index: cgraphunit.c
===================================================================
--- cgraphunit.c	(revision 161008)
+++ cgraphunit.c	(working copy)
@@ -2345,7 +2345,6 @@ cgraph_redirect_edge_call_stmt_to_callee
 {
   tree decl = gimple_call_fndecl (e->call_stmt);
   gimple new_stmt;
-  gimple_stmt_iterator gsi;
 #ifdef ENABLE_CHECKING
   struct cgraph_node *node;
 #endif
@@ -2383,13 +2382,15 @@ cgraph_redirect_edge_call_stmt_to_callee
     SSA_NAME_DEF_STMT (gimple_vdef (new_stmt)) = new_stmt;
   gimple_call_set_fndecl (new_stmt, e->callee->decl);
 
-  gsi = gsi_for_stmt (e->call_stmt);
-  gsi_replace (&gsi, new_stmt, true);
+  if (new_stmt != e->call_stmt)
+    {
+      gimple_stmt_iterator gsi = gsi_for_stmt (e->call_stmt);
+      gsi_replace (&gsi, new_stmt, true);
+      /* Clear its BB in case it is on the MODIFIED_NORETURN_CALLS list.  */
+      gimple_set_bb (e->call_stmt, NULL);
+    }
   update_stmt (new_stmt);
 
-  /* Update EH information too, just in case.  */
-  maybe_clean_or_replace_eh_stmt (e->call_stmt, new_stmt);
-
   cgraph_set_call_stmt_including_clones (e->caller, e->call_stmt, new_stmt);
 
   if (cgraph_dump_file)
Index: gimple.c
===================================================================
--- gimple.c	(revision 161008)
+++ gimple.c	(working copy)
@@ -3085,14 +3085,8 @@ gimple_call_copy_skip_args (gimple stmt,
   gimple_set_block (new_stmt, gimple_block (stmt));
   if (gimple_has_location (stmt))
     gimple_set_location (new_stmt, gimple_location (stmt));
-
-  /* Carry all the flags to the new GIMPLE_CALL.  */
+  gimple_call_copy_flags (new_stmt, stmt);
   gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
-  gimple_call_set_tail (new_stmt, gimple_call_tail_p (stmt));
-  gimple_call_set_cannot_inline (new_stmt, gimple_call_cannot_inline_p (stmt));
-  gimple_call_set_return_slot_opt (new_stmt, gimple_call_return_slot_opt_p (stmt));
-  gimple_call_set_from_thunk (new_stmt, gimple_call_from_thunk_p (stmt));
-  gimple_call_set_va_arg_pack (new_stmt, gimple_call_va_arg_pack_p (stmt));
 
   gimple_set_modified (new_stmt, true);