ubsan: Fix ICEs with DECL_REGISTER tests [PR101624]

Hi!

The following testcase ICEs, because the base is a CONST_DECL for
the Fortran parameter, and ubsan/sanopt uses DECL_REGISTER macro on it.
/* In VAR_DECL and PARM_DECL nodes, nonzero means declared `register'.  */
#define DECL_REGISTER(NODE) (DECL_WRTL_CHECK (NODE)->decl_common.decl_flag_0)
while CONST_DECL doesn't satisfy DECL_WRTL_CHECK.

The following patch checks explicitly for VAR_DECL/PARM_DECL/RESULT_DECL
only before using DECL_REGISTER, assumes other decls aren't DECL_REGISTER.
Not really sure about RESULT_DECL but it at least satisfies DECL_WRTL_CHECK...

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk and
backports?

2021-07-28  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/101624
	* ubsan.c (maybe_instrument_pointer_overflow,
	instrument_object_size): Only test DECL_REGISTER on VAR_DECLs,
	PARM_DECLs or RESULT_DECLs.
	* sanopt.c (maybe_optimize_ubsan_ptr_ifn): Likewise.

	* gfortran.dg/ubsan/ubsan.exp: New file.
	* gfortran.dg/ubsan/pr101624.f90: New test.


	Jakub

On Wed, 28 Jul 2021, Jakub Jelinek wrote:

> Hi!
> 
> The following testcase ICEs, because the base is a CONST_DECL for
> the Fortran parameter, and ubsan/sanopt uses DECL_REGISTER macro on it.
> /* In VAR_DECL and PARM_DECL nodes, nonzero means declared `register'.  */
> #define DECL_REGISTER(NODE) (DECL_WRTL_CHECK (NODE)->decl_common.decl_flag_0)
> while CONST_DECL doesn't satisfy DECL_WRTL_CHECK.
> 
> The following patch checks explicitly for VAR_DECL/PARM_DECL/RESULT_DECL
> only before using DECL_REGISTER, assumes other decls aren't DECL_REGISTER.
> Not really sure about RESULT_DECL but it at least satisfies DECL_WRTL_CHECK...
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk and
> backports?

OK.

> 2021-07-28  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR middle-end/101624
> 	* ubsan.c (maybe_instrument_pointer_overflow,
> 	instrument_object_size): Only test DECL_REGISTER on VAR_DECLs,
> 	PARM_DECLs or RESULT_DECLs.
> 	* sanopt.c (maybe_optimize_ubsan_ptr_ifn): Likewise.
> 
> 	* gfortran.dg/ubsan/ubsan.exp: New file.
> 	* gfortran.dg/ubsan/pr101624.f90: New test.
> 
> --- gcc/ubsan.c.jj	2021-05-10 12:22:30.425451947 +0200
> +++ gcc/ubsan.c	2021-07-27 19:18:05.926969704 +0200
> @@ -1443,7 +1443,10 @@ maybe_instrument_pointer_overflow (gimpl
>    tree base;
>    if (decl_p)
>      {
> -      if (DECL_REGISTER (inner))
> +      if ((VAR_P (inner)
> +	   || TREE_CODE (inner) == PARM_DECL
> +	   || TREE_CODE (inner) == RESULT_DECL)
> +	  && DECL_REGISTER (inner))
>  	return;
>        base = inner;
>        /* If BASE is a fixed size automatic variable or
> @@ -2115,7 +2118,10 @@ instrument_object_size (gimple_stmt_iter
>    tree base;
>    if (decl_p)
>      {
> -      if (DECL_REGISTER (inner))
> +      if ((VAR_P (inner)
> +	   || TREE_CODE (inner) == PARM_DECL
> +	   || TREE_CODE (inner) == RESULT_DECL)
> +	  && DECL_REGISTER (inner))
>  	return;
>        base = inner;
>      }
> --- gcc/sanopt.c.jj	2021-06-14 12:27:18.605410685 +0200
> +++ gcc/sanopt.c	2021-07-27 19:16:45.667035649 +0200
> @@ -492,7 +492,10 @@ maybe_optimize_ubsan_ptr_ifn (sanopt_ctx
>  				  &unsignedp, &reversep, &volatilep);
>        if ((offset == NULL_TREE || TREE_CODE (offset) == INTEGER_CST)
>  	  && DECL_P (base)
> -	  && !DECL_REGISTER (base)
> +	  && ((!VAR_P (base)
> +	       && TREE_CODE (base) != PARM_DECL
> +	       && TREE_CODE (base) != RESULT_DECL)
> +	      || !DECL_REGISTER (base))
>  	  && pbitpos.is_constant (&bitpos))
>  	{
>  	  offset_int expr_offset;
> --- gcc/testsuite/gfortran.dg/ubsan/ubsan.exp.jj	2021-07-27 19:59:24.889038766 +0200
> +++ gcc/testsuite/gfortran.dg/ubsan/ubsan.exp	2021-07-27 20:00:18.538326168 +0200
> @@ -0,0 +1,38 @@
> +# Copyright (C) 2021 Free Software Foundation, Inc.
> +#
> +# This file is part of GCC.
> +#
> +# GCC is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3, or (at your option)
> +# any later version.
> +#
> +# GCC is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with GCC; see the file COPYING3.  If not see
> +# <http://www.gnu.org/licenses/>.
> +
> +# GCC testsuite for gfortran that checks undefined behavior sanitizer.
> +
> +# Load support procs.
> +load_lib gfortran-dg.exp
> +load_lib ubsan-dg.exp
> +
> +
> +# Initialize `dg'.
> +dg-init
> +ubsan_init
> +
> +# Main loop.
> +if [check_effective_target_fsanitize_undefined] {
> +    gfortran-dg-runtest [lsort \
> +       [glob -nocomplain $srcdir/$subdir/*.\[fF\]{,90,95,03,08} ] ] "" ""
> +}
> +
> +# All done.
> +ubsan_finish
> +dg-finish
> --- gcc/testsuite/gfortran.dg/ubsan/pr101624.f90.jj	2021-07-27 19:56:51.831071747 +0200
> +++ gcc/testsuite/gfortran.dg/ubsan/pr101624.f90	2021-07-27 19:59:14.634174975 +0200
> @@ -0,0 +1,13 @@
> +! PR middle-end/101624
> +! { dg-do compile }
> +! { dg-options "-O2 -fsanitize=undefined" }
> +
> +complex function foo (x)
> +  complex, intent(in) :: x
> +  foo = aimag (x)
> +end
> +program pr101624
> +  complex, parameter :: a = (0.0, 1.0)
> +  complex :: b, foo
> +  b = foo (a)
> +end
> 
> 	Jakub
> 
>