Re: Tree checking failure in jc1

[Dave Korn <dave dot korn dot cygwin at gmail dot com>]

On 10/12/2010 20:49, Dave Korn wrote:

>   I found a couple of new FAILs in my latest libjava testrun:
> 
>> FAIL: newarray_overflow -O3 compilation from source
>> FAIL: newarray_overflow -O3 -findirect-dispatch compilation from source
> 
>   These turn out to be tree checking failures:
> 
>> In file included from <built-in>:3:0:
>> newarray_overflow.java:20:0: internal compiler error: tree check: expected class
>>  'type', have 'declaration' (function_decl) in put_decl_node, at java/lang.c:405

  This turned out to be a second bug, triggered by -fdump-tree-all attempting
to output some line of mangled gimple.  Without that flag, or ...

> 	      put_decl_node (TREE_CODE (DECL_CONTEXT (node)) == FUNCTION_DECL
>                                ? DECL_CONTEXT (node)
>                                : TYPE_NAME (DECL_CONTEXT (node)),
>                                verbosity);

... with the suggested fix, compilation proceeds to the site of the actual
crash that occurred in the testsuite run: a segfault in gimple.c#walk_gimple_op():

> Program received signal SIGSEGV, Segmentation fault.
> 0x007cfdbe in walk_gimple_op (stmt=0x7fe106e0, callback_op=0x4a0ef0 <verify_expr
> .265801>, wi=0x326c554) at /gnu/gcc/gcc/gcc/gimple.c:2841
> 2841      return !AGGREGATE_TYPE_P (type);
> (gdb) call debug_gimple_stmt (stmt)
> newarray_overflow.int_check.__builtin_prefetch (D.1284_85, 0, );
> 
> (gdb)

  I think this is the same as PR29710(*) "gnat ICEs on -fprefetch-loop-arrays
-O1", so I'll put the rest of my findings there.  Note that weird missing
third argument: it turns out that integer_three_node hasn't been initialised
at the time that issue_prefetch_ref() attempts to pass it to gimple_build_call().

    cheers,
      DaveK
-- 
(*) - http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29710