[patch] Fix LTO warning on types with variable offsets

[Eric Botcazou]

Hi,

this is exposed by ACATS cc54002.  The LTO compiler fails to merge compatible 
types when they contain a field with variable (self-referential) offset and 
thus issues a warning.  Such an offset is meaningless once gimplification is 
done because it has been instantiated as operand #2 of the COMPONENT_REF 
built for each access, and is therefore reset.

Tested on i586-suse-linux, Ok for mainline?


2010-05-14  Eric Botcazou  <ebotcazou@adacore.com>

	* gimple.h (compare_field_offset): Rename into...
	(gimple_compare_field_offset): ...this.
	* gimple.c (compare_field_offset): Rename into...
	(gimple_compare_field_offset): ...this.  Compare the full access if
	the offset is self-referential.
	(gimple_types_compatible_p): Adjust for above renaming.
	* lto-streamer-in.c (input_gimple_stmt): Likewise.  Also compare the
	DECL_NONADDRESSABLE_P flag of fields before merging them.


2010-05-14  Eric Botcazou  <ebotcazou@adacore.com>

	* gnat.dg/lto9.adb: New test.
	* gnat.dg/lto9_pkg1.ads: New helper.
	* gnat.dg/lto9_pkg2.ad[sb]: Likewise.


-- 
Eric Botcazou
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