Re: [C++ PATCH] TREE_LISTectomy of rtti.c

[Nick Burrett <nick at sqrt dot co dot uk>]

Nathan Sidwell wrote:
> Hi,
> I've installed this patch, which replaces rtti's use of TREE_LIST with a 
> bespoke structure and VEC.
>
> booted & tested on i686-pc-linux-gnu.

> *************** get_tinfo_decl (tree type)
> *** 343,351 ****
>     d = IDENTIFIER_GLOBAL_VALUE (name);
>     if (!d)
>       {
> !       tree var_desc = get_pseudo_ti_desc (type);
>   
> !       d = build_lang_decl (VAR_DECL, name, TINFO_PSEUDO_TYPE (var_desc));
>         SET_DECL_ASSEMBLER_NAME (d, name);
>         /* Remember the type it is for.  */
>         TREE_TYPE (name) = type;
> --- 369,378 ----
>     d = IDENTIFIER_GLOBAL_VALUE (name);
>     if (!d)
>       {
> !       tinfo_s *ti = VEC_index (tinfo_s, tinfo_descs,
> ! 			       get_pseudo_ti_index (type));
>   
> !       d = build_lang_decl (VAR_DECL, name, ti->type);
>         SET_DECL_ASSEMBLER_NAME (d, name);
>         /* Remember the type it is for.  */
>         TREE_TYPE (name) = type;

Trying this patch with an arm-elf-linux target, I find the build fails 
in libstdc++:

../../../../libstdc++-v3/src/codecvt.cc -o codecvt.o
/home/nick/riscos-elf/gcc-4.1/arm-elf-riscos/arm-elf-riscos/libstdc++-v3/include/bits/locale_facets.h:676: 
internal compiler error: Segmentation fault

'ti->type' in this instance is NULL.


Program received signal SIGSEGV, Segmentation fault.
layout_decl (decl=0x8cd0a8c, known_align=0) at ../../gcc/stor-layout.c:318
318       DECL_UNSIGNED (decl) = TYPE_UNSIGNED (type);
(gdb) bt
#0  layout_decl (decl=0x8cd0a8c, known_align=0) at 
../../gcc/stor-layout.c:318
#1  0x082a2e73 in build_decl_stat (code=VAR_DECL, name=0x0, type=0x0) at 
../../gcc/tree.c:2873
#2  0x08082175 in build_lang_decl (code=VAR_DECL, name=0x8c99e6c, 
type=0x0) at ../../gcc/cp/lex.c:668
#3  0x08090483 in get_tinfo_decl (type=0x87304a4) at ../../gcc/cp/rtti.c:375
#4  0x08077c28 in accumulate_vtbl_inits (binfo=0x89bad40, 
orig_binfo=0x89bad40, rtti_binfo=0x89bad40, t=0x87304a4, 
inits=0x8ccd7b0) at ../../gcc/cp/class.c:7654
#5  0x08078af1 in finish_struct_1 (t=0x87304a4) at ../../gcc/cp/class.c:6576
#6  0x08079a9d in finish_struct (t=0x87304a4, attributes=0x0) at 
../../gcc/cp/class.c:5114