[Bug c++/57945] [4.9 Regression] ICE: in varpool_get_node, at cgraph.h:840

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57945

--- Comment #6 from Jan Hubicka <hubicka at ucw dot cz> ---
OK, somewhat confusing on the testcase above is that j is defined, but C++ FE
never consider it uses and thus never passes it to middle-end.

The problem is that C++ FE chose to first assemble alias:
#0  assemble_alias (decl=<var_decl 0x7ffff70401c8 i>, target=
    <identifier_node 0x7ffff7047c08 j>) at ../../gcc/varasm.c:5682
#1  0x0000000000ca94cc in rest_of_decl_compilation (decl=<var_decl
0x7ffff70401c8 i>, 
    top_level=1, at_end=0) at ../../gcc/passes.c:205
#2  0x0000000000610745 in make_rtl_for_nonlocal_decl (decl=<var_decl
0x7ffff70401c8 i>, 
    init=<tree 0x0>, asmspec=0x0) at ../../gcc/cp/decl.c:5909
#3  0x0000000000613173 in cp_finish_decl (decl=<var_decl 0x7ffff70401c8 i>,
init=
    <tree 0x0>, init_const_expr_p=false, asmspec_tree=<tree 0x0>, flags=1)
    at ../../gcc/cp/decl.c:6480
#4  0x000000000073291d in cp_parser_init_declarator (parser=0x7ffff7048000, 
    decl_specifiers=0x7fffffffe2f0, checks=0x0,
function_definition_allowed_p=true, 
    member_p=false, declares_class_or_enum=0,
function_definition_p=0x7fffffffe37f, 
    maybe_range_for_decl=0x0) at ../../gcc/cp/parser.c:16804
#5  0x0000000000729785 in cp_parser_simple_declaration (parser=0x7ffff7048000, 
    function_definition_allowed_p=true, maybe_range_for_decl=0x0)
    at ../../gcc/cp/parser.c:11195
#6  0x0000000000729573 in cp_parser_block_declaration (parser=0x7ffff7048000,
statement_p=
    false) at ../../gcc/cp/parser.c:11076
#7  0x00000000007292ee in cp_parser_declaration (parser=0x7ffff7048000)
    at ../../gcc/cp/parser.c:10973
#8  0x0000000000728e68 in cp_parser_declaration_seq_opt (parser=0x7ffff7048000)
    at ../../gcc/cp/parser.c:10859
#9  0x000000000071cfdd in cp_parser_translation_unit (parser=0x7ffff7048000)
    at ../../gcc/cp/parser.c:4018
#10 0x00000000007519b4 in c_parse_file () at ../../gcc/cp/parser.c:31322
#11 0x00000000008b5e5d in c_common_parse_file () at
../../gcc/c-family/c-opts.c:1056
#12 0x0000000000daf45f in compile_file () at ../../gcc/toplev.c:547
#13 0x0000000000db14da in do_compile () at ../../gcc/toplev.c:1887
#14 0x0000000000db1649 in toplev_main (argc=3, argv=0x7fffffffe6a8)
    at ../../gcc/toplev.c:1963
#15 0x000000000155cb50 in main (argc=3, argv=0x7fffffffe6a8) at
../../gcc/main.c:36

and then finalize variable

#0  varpool_finalize_decl (decl=<var_decl 0x7ffff70401c8 i>) at
../../gcc/cgraphunit.c:824
#1  0x0000000000ca96ca in rest_of_decl_compilation (decl=<var_decl
0x7ffff70401c8 i>, 
    top_level=1, at_end=0) at ../../gcc/passes.c:238
#2  0x0000000000610745 in make_rtl_for_nonlocal_decl (decl=<var_decl
0x7ffff70401c8 i>, 
    init=<tree 0x0>, asmspec=0x0) at ../../gcc/cp/decl.c:5909

It should do just one of these.

Index: passes.c
===================================================================
--- passes.c    (revision 206013)
+++ passes.c    (working copy)
@@ -187,6 +187,8 @@ rest_of_decl_compilation (tree decl,
               int top_level,
               int at_end)
 {
+  bool finalize = true;
+
   /* We deferred calling assemble_alias so that we could collect
      other attributes such as visibility.  Emit the alias now.  */
   if (!in_lto_p)
@@ -203,6 +205,7 @@ rest_of_decl_compilation (tree decl,
     DECL_EXTERNAL (decl) = 0;
     TREE_STATIC (decl) = 1;
     assemble_alias (decl, alias);
+    finalize = false;
       }
   }

@@ -234,7 +237,7 @@ rest_of_decl_compilation (tree decl,
          rebuild it.  */
       if (in_lto_p && !at_end)
         ;
-      else if (TREE_CODE (decl) != FUNCTION_DECL)
+      else if (finalize && TREE_CODE (decl) != FUNCTION_DECL)
         varpool_finalize_decl (decl);
     }