Re: [C++ PATCH] Fix ICE in warn_placement_new_too_small (PR c++/70488)

[Jeff Law <law at redhat dot com>]

On 04/01/2016 09:11 AM, Jakub Jelinek wrote:
> Hi!
>
> The new warn_placement_new_too_small function blindly assumes that
> if {DECL,TYPE}_SIZE_UNIT is non-NULL, then it must be INTEGER_CST
> that fits into uhwi.  That is not the case, it could be a VLA, etc.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
> ok for trunk?
>
> OT, as I said in bugzilla, I see very questionable code in that function
> too, no idea what Martin meant with that:
>    while (TREE_CODE (oper) == COMPONENT_REF)
>      {
>        tree op0 = oper;
>        while (TREE_CODE (op0 = TREE_OPERAND (op0, 0)) == COMPONENT_REF);
>        if (TREE_CODE (op0) == VAR_DECL)
>          var_decl = op0;
>        oper = TREE_OPERAND (oper, 1);
>      }
> TREE_OPERAND (oper, 1) of a COMPONENT_REF should be always a FIELD_DECL,
> so this will never loop.  Did you mean to use if instead of while, something
> different?
Or perhaps TREE_OPERAND (oper, 0)?

> 2016-04-01  Jakub Jelinek  <jakub@redhat.com>
> 	    Marek Polacek  <polacek@redhat.com>
>
> 	PR c++/70488
> 	* init.c (warn_placement_new_too_small): Test whether
> 	DECL_SIZE_UNIT or TYPE_SIZE_UNIT are integers that fit into uhwi.
>
> 	* g++.dg/init/new47.C: New test.
OK.
jeff