[patch] Fix LTO regression in Ada

[Eric Botcazou]

Hi,

this is a regression present on mainline and 4.7 branch.  On the attached 
testcase, the compiler aborts in LTO mode with:

eric@atlantis:~/build/gcc/native32> gcc/xgcc -Bgcc -S lto11.adb -O -flto
+===========================GNAT BUG DETECTED==============================+
| 4.8.0 20120506 (experimental) [trunk revision 187216] (i586-suse-linux)
| tree code 'call_expr' is not supported in LTO streams           

The problem is that the Ada compiler started to use DECL_ORIGINAL_TYPE in 4.7.x 
and the type in this field can have arbitrary expressions as TYPE_SIZE, for 
example expressions with CALL_EXPRs.  Now the type is both not gimplified and 
streamed in LTO mode, so the CALL_EXPRs are sent to the streamer as-is.

The immediate solution would be not to stream DECL_ORIGINAL_TYPE (and clear it 
in free_lang_data_in_decl), but this yields a regression in C++ with -flto -g 
(ICE in splice_child_die).  Therefore, the patch implements the alternate 
solution of gimplifying DECL_ORIGINAL_TYPE.

Bootstrapped/regtested on x86_64-suse-linux, OK for mainline and 4.7 branch?


2012-05-09  Eric Botcazou  <ebotcazou@adacore.com>

	* gimplify.c (gimplify_decl_expr): For a TYPE_DECL, gimplify the
	DECL_ORIGINAL_TYPE if it is present.


2012-05-09  Eric Botcazou  <ebotcazou@adacore.com>

	* gnat.dg/lto11.ad[sb]: New test.


-- 
Eric Botcazou
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