Fix g++.dg/torture/stackalign/eh-alloca-1.C with LTO plugin

[Richard Guenther]

On Wed, 1 Dec 2010, Jan Hubicka wrote:

> Hi,
> this patch fixes the stackalign issues.  What happens here is that
> dw2_force_const_mem produce an label that is supposed to point to given
> constant in memory.  This is realized by dw2_output_indirect_constant_1 that
> produce variable with the name smatching the label's name and appropriate
> constructor.
> 
> This is used to encode personality routines for EH.
> 
> The catch is that the label name is "*.Lblah", while the static variable in LTO
> mode ends up being "*.Lblah.1234" because we do the mangling of static vars.
> This patch simply avoids all the mangling by enforcing the assembler name to be
> same as label's assembler name.  It is what we want anyway.
> 
> I am not quite sure why this happens only with linker plugin. I assume that we
> optimize the functions differently resulting in different EH info.
> 
> Regtested/bootstrapped x86_64-linux, OK?
> 
> Honza
> 
> 	* dwarf2asm.c (dw2_output_indirect_constant_1): Set assembler name
> 	of the new decl.
> Index: dwarf2asm.c
> ===================================================================
> --- dwarf2asm.c	(revision 167242)
> +++ dwarf2asm.c	(working copy)
> @@ -920,6 +920,7 @@ dw2_output_indirect_constant_1 (splay_tr
>  
>    sym_ref = gen_rtx_SYMBOL_REF (Pmode, sym);
>    sym = targetm.strip_name_encoding (sym);
> +  SET_DECL_ASSEMBLER_NAME (decl, id);

Shouldn't this be done before the DECL_ASSEMBLER_NAME use above?

Why doesn't it just work in mangled form?  We generate that decl
at this very place, so I don't see how we get the chance to mangle it
anyway.

Richard.