LTO ICE in D Frontend

[Iain Buclaw <ibuclaw at gdcproject dot org>]

Hi,

I'm trying to get to the bottom of a bug when using the D front-end with -flto.

When compiling anything, it always ICEs at in
streamer_get_pickled_tree, at tree-streamer-in.c.

The of it appears to be that the LTO frontend seems to never retrieve
what it is expected to find.  But I don't know what could be missing
from the code generation on my side to sort that out.


The following minimal test that yields an ICE.
---
extern(C) int test = void;


I had set a breakpoint at hash_tree and looked at debug_tree output
from an equivalent program in C++, but nothing stands out as wrong
here to me.

Any insight would be helpful.


// D
DECL_NAME:
 <identifier_node 0x7ffff66981b8 test>

DECL_CONTEXT: (null_tree)

DECL_SIZE:
 <integer_cst 0x7ffff6540d98 type <integer_type 0x7ffff65500a8
bitsizetype> constant 32>

DECL_SIZE_UNIT:
 <integer_cst 0x7ffff6540db0 type <integer_type 0x7ffff6550000
sizetype> constant 4>


VAR_DECL:
 <var_decl 0x7ffff6548a20 test
    type <integer_type 0x7ffff65505e8 int public SI
        size <integer_cst 0x7ffff6540d98 constant 32>
        unit size <integer_cst 0x7ffff6540db0 constant 4>
        align 32 symtab 0 alias set 0 canonical type 0x7ffff65505e8
precision 32 min <integer_cst 0x7ffff6540d50 -2147483648> max
<integer_cst 0x7ffff
6540d68 2147483647>
        pointer_to_this <pointer_type 0x7ffff6557690>>
    used public static tls-initial-exec SI file test.d line 1 col 0
size <integer_cst 0x7ffff6540d98 32> unit size <integer_cst
0x7ffff6540db0 4>
    align 32
    (mem/c:SI (symbol_ref:DI ("test") [flags 0x2a] <var_decl
0x7ffff6548a20 test>) [0 test+0 S4 A32])>




// C++
DECL_NAME:
 <identifier_node 0x7ffff66ad210 test public bindings <0x7ffff66ab078>
local bindings <(nil)>>

DECL_CONTEXT:
 <translation_unit_decl 0x7ffff65580a0 D.1 VOID file (null) line 0 col 0
    align 1>

DECL_SIZE:
 <integer_cst 0x7ffff655e030 type <integer_type 0x7ffff655a0a8
bitsizetype> constant 32>

DECL_SIZE_UNIT:
 <integer_cst 0x7ffff655e048 type <integer_type 0x7ffff655a000
sizetype> constant 4>

 VAR_DECL:
  <var_decl 0x7ffff654aa20 test
    type <integer_type 0x7ffff655a5e8 int public SI
        size <integer_cst 0x7ffff655e030 constant 32>
        unit size <integer_cst 0x7ffff655e048 constant 4>
        align 32 symtab 0 alias set 0 canonical type 0x7ffff655a5e8
precision 32 min <integer_cst 0x7ffff6540fd8 -2147483648> max
<integer_cst 0x7ffff
655e000 2147483647>
        pointer_to_this <pointer_type 0x7ffff6562690>>
    public static SI file test2.cc line 2 col 5 size <integer_cst
0x7ffff655e030 32> unit size <integer_cst 0x7ffff655e048 4>
    align 32 context <translation_unit_decl 0x7ffff65580a0 D.1>

    (mem/c:SI (symbol_ref:DI ("test") [flags 0x2] <var_decl
0x7ffff654aa20 test>) [0 test+0 S4 A32]) chain <function_decl
0x7ffff66a8600 __cxa_call_un
expected>>