[PATCH] Disable __asan_init for KASan

[Yury Gribov]

Hi all,

This patch disables generation of asan_init calls for KASan as discussed 
in https://lkml.org/lkml/2014/9/26/711

Bootstrapped and regtested no x64. Ok to commit?

-Y
commit 91c015e54687666f4abf6745f33c2eee8e569d17
Author: Yury Gribov <y.gri...@samsung.com>
Date:   Fri Oct 3 11:53:38 2014 +0400

    2014-10-03  Yury Gribov  <y.gri...@samsung.com>
    
    gcc/
    	* asan.c (asan_finish_file): Disable __asan_init calls for KASan;
    	don't emit empty ctors.

diff --git a/gcc/asan.c b/gcc/asan.c
index f520eab..247661a 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -2400,8 +2400,11 @@ asan_finish_file (void)
      nor after .LASAN* array.  */
   flag_sanitize &= ~SANITIZE_ADDRESS;
 
-  tree fn = builtin_decl_implicit (BUILT_IN_ASAN_INIT);
-  append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements);
+  if (flag_sanitize & SANITIZE_USER_ADDRESS)
+    {
+      tree fn = builtin_decl_implicit (BUILT_IN_ASAN_INIT);
+      append_to_statement_list (build_call_expr (fn, 0), &asan_ctor_statements);
+    }
   FOR_EACH_DEFINED_VARIABLE (vnode)
     if (TREE_ASM_WRITTEN (vnode->decl)
 	&& asan_protect_global (vnode->decl))
@@ -2438,7 +2441,7 @@ asan_finish_file (void)
       DECL_INITIAL (var) = ctor;
       varpool_node::finalize_decl (var);
 
-      fn = builtin_decl_implicit (BUILT_IN_ASAN_REGISTER_GLOBALS);
+      tree fn = builtin_decl_implicit (BUILT_IN_ASAN_REGISTER_GLOBALS);
       tree gcount_tree = build_int_cst (pointer_sized_int_node, gcount);
       append_to_statement_list (build_call_expr (fn, 2,
 						 build_fold_addr_expr (var),
@@ -2453,8 +2456,9 @@ asan_finish_file (void)
       cgraph_build_static_cdtor ('D', dtor_statements,
 				 MAX_RESERVED_INIT_PRIORITY - 1);
     }
-  cgraph_build_static_cdtor ('I', asan_ctor_statements,
-			     MAX_RESERVED_INIT_PRIORITY - 1);
+  if (asan_ctor_statements)
+    cgraph_build_static_cdtor ('I', asan_ctor_statements,
+			       MAX_RESERVED_INIT_PRIORITY - 1);
   flag_sanitize |= SANITIZE_ADDRESS;
 }