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From: Richard Biener <rguenther@suse.de>
To: Qing Zhao <qing.zhao@oracle.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH 1/1] Replace flag_strict_flex_arrays with DECL_NOT_FLEXARRAY in middle-end
Date: Fri, 13 Jan 2023 07:00:24 +0000 (UTC)	[thread overview]
Message-ID: <nycvar.YFH.7.77.849.2301130700160.12651@jbgna.fhfr.qr> (raw)
In-Reply-To: <20230112230406.2023047-2-qing.zhao@oracle.com>

On Thu, 12 Jan 2023, Qing Zhao wrote:

> We should not directly check flag_strict_flex_arrays in the middle end.
> Instead, check DECL_NOT_FLEXARRAY(array_field_decl) which is set by
> C/C++ FEs according to -fstrict-flex-arrays and the corresponding attribute
> attached to the array_field.
> 
> As a result, We will lose the LEVEL information of -fstrict-flex-arrays in
> the middle end. -Wstrict-flex-arrays will not be able to issue such
> information. update the testing cases accordingly.

OK.

Thanks,
Richard.

> gcc/ChangeLog:
> 
> 	* attribs.cc (strict_flex_array_level_of): Move this function to ...
> 	* attribs.h (strict_flex_array_level_of): Remove the declaration.
> 	* gimple-array-bounds.cc (array_bounds_checker::check_array_ref):
> 	replace the referece to strict_flex_array_level_of with
> 	DECL_NOT_FLEXARRAY.
> 	* tree.cc (component_ref_size): Likewise.
> 
> gcc/c/ChangeLog:
> 
> 	* c-decl.cc (strict_flex_array_level_of): ... here.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.dg/Warray-bounds-flex-arrays-1.c: Delete the level information
> 	from the message issued by -Wstrict-flex-arrays.
> 	* gcc.dg/Warray-bounds-flex-arrays-2.c: Likewise.
> 	* gcc.dg/Warray-bounds-flex-arrays-3.c: Likewise.
> 	* gcc.dg/Warray-bounds-flex-arrays-4.c: Likewise.
> 	* gcc.dg/Warray-bounds-flex-arrays-5.c: Likewise.
> 	* gcc.dg/Warray-bounds-flex-arrays-6.c: Likewise.
> 	* gcc.dg/Wstrict-flex-arrays-2.c: Likewise.
> 	* gcc.dg/Wstrict-flex-arrays-3.c: Likewise.
> 	* gcc.dg/Wstrict-flex-arrays.c: Likewise.
> ---
>  gcc/attribs.cc                                | 30 ------------
>  gcc/attribs.h                                 |  2 -
>  gcc/c/c-decl.cc                               | 28 +++++++++++
>  gcc/gimple-array-bounds.cc                    | 46 ++++---------------
>  .../gcc.dg/Warray-bounds-flex-arrays-1.c      |  2 +-
>  .../gcc.dg/Warray-bounds-flex-arrays-2.c      |  4 +-
>  .../gcc.dg/Warray-bounds-flex-arrays-3.c      |  6 +--
>  .../gcc.dg/Warray-bounds-flex-arrays-4.c      |  2 +-
>  .../gcc.dg/Warray-bounds-flex-arrays-5.c      |  4 +-
>  .../gcc.dg/Warray-bounds-flex-arrays-6.c      |  6 +--
>  gcc/testsuite/gcc.dg/Wstrict-flex-arrays-2.c  |  8 ++--
>  gcc/testsuite/gcc.dg/Wstrict-flex-arrays-3.c  |  8 ++--
>  gcc/testsuite/gcc.dg/Wstrict-flex-arrays.c    |  8 ++--
>  gcc/tree.cc                                   | 37 +++------------
>  14 files changed, 68 insertions(+), 123 deletions(-)
> 
> diff --git a/gcc/attribs.cc b/gcc/attribs.cc
> index 49cb299a3c1..7db730cf831 100644
> --- a/gcc/attribs.cc
> +++ b/gcc/attribs.cc
> @@ -2456,36 +2456,6 @@ init_attr_rdwr_indices (rdwr_map *rwm, tree attrs)
>      }
>  }
>  
> -/* Get the LEVEL of the strict_flex_array for the ARRAY_FIELD based on the
> -   values of attribute strict_flex_array and the flag_strict_flex_arrays.  */
> -unsigned int
> -strict_flex_array_level_of (tree array_field)
> -{
> -  gcc_assert (TREE_CODE (array_field) == FIELD_DECL);
> -  unsigned int strict_flex_array_level = flag_strict_flex_arrays;
> -
> -  tree attr_strict_flex_array
> -    = lookup_attribute ("strict_flex_array", DECL_ATTRIBUTES (array_field));
> -  /* If there is a strict_flex_array attribute attached to the field,
> -     override the flag_strict_flex_arrays.  */
> -  if (attr_strict_flex_array)
> -    {
> -      /* Get the value of the level first from the attribute.  */
> -      unsigned HOST_WIDE_INT attr_strict_flex_array_level = 0;
> -      gcc_assert (TREE_VALUE (attr_strict_flex_array) != NULL_TREE);
> -      attr_strict_flex_array = TREE_VALUE (attr_strict_flex_array);
> -      gcc_assert (TREE_VALUE (attr_strict_flex_array) != NULL_TREE);
> -      attr_strict_flex_array = TREE_VALUE (attr_strict_flex_array);
> -      gcc_assert (tree_fits_uhwi_p (attr_strict_flex_array));
> -      attr_strict_flex_array_level = tree_to_uhwi (attr_strict_flex_array);
> -
> -      /* The attribute has higher priority than flag_struct_flex_array.  */
> -      strict_flex_array_level = attr_strict_flex_array_level;
> -    }
> -  return strict_flex_array_level;
> -}
> -
> -
>  /* Return the access specification for a function parameter PARM
>     or null if the current function has no such specification.  */
>  
> diff --git a/gcc/attribs.h b/gcc/attribs.h
> index e7540f71d6a..140e70b64e0 100644
> --- a/gcc/attribs.h
> +++ b/gcc/attribs.h
> @@ -398,6 +398,4 @@ extern void init_attr_rdwr_indices (rdwr_map *, tree);
>  extern attr_access *get_parm_access (rdwr_map &, tree,
>  				     tree = current_function_decl);
>  
> -extern unsigned int strict_flex_array_level_of (tree);
> -
>  #endif // GCC_ATTRIBS_H
> diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
> index d76ffb3380d..38647c100c1 100644
> --- a/gcc/c/c-decl.cc
> +++ b/gcc/c/c-decl.cc
> @@ -9047,6 +9047,34 @@ finish_incomplete_vars (tree incomplete_vars, bool toplevel)
>      }
>  }
>  
> +/* Get the LEVEL of the strict_flex_array for the ARRAY_FIELD based on the
> +   values of attribute strict_flex_array and the flag_strict_flex_arrays.  */
> +static unsigned int
> +strict_flex_array_level_of (tree array_field)
> +{
> +  gcc_assert (TREE_CODE (array_field) == FIELD_DECL);
> +  unsigned int strict_flex_array_level = flag_strict_flex_arrays;
> +
> +  tree attr_strict_flex_array
> +    = lookup_attribute ("strict_flex_array", DECL_ATTRIBUTES (array_field));
> +  /* If there is a strict_flex_array attribute attached to the field,
> +     override the flag_strict_flex_arrays.  */
> +  if (attr_strict_flex_array)
> +    {
> +      /* Get the value of the level first from the attribute.  */
> +      unsigned HOST_WIDE_INT attr_strict_flex_array_level = 0;
> +      gcc_assert (TREE_VALUE (attr_strict_flex_array) != NULL_TREE);
> +      attr_strict_flex_array = TREE_VALUE (attr_strict_flex_array);
> +      gcc_assert (TREE_VALUE (attr_strict_flex_array) != NULL_TREE);
> +      attr_strict_flex_array = TREE_VALUE (attr_strict_flex_array);
> +      gcc_assert (tree_fits_uhwi_p (attr_strict_flex_array));
> +      attr_strict_flex_array_level = tree_to_uhwi (attr_strict_flex_array);
> +
> +      /* The attribute has higher priority than flag_struct_flex_array.  */
> +      strict_flex_array_level = attr_strict_flex_array_level;
> +    }
> +  return strict_flex_array_level;
> +}
>  
>  /* Determine whether the FIELD_DECL X is a flexible array member according to
>     the following info:
> diff --git a/gcc/gimple-array-bounds.cc b/gcc/gimple-array-bounds.cc
> index 116200a317f..66fd46e9b6c 100644
> --- a/gcc/gimple-array-bounds.cc
> +++ b/gcc/gimple-array-bounds.cc
> @@ -350,18 +350,14 @@ array_bounds_checker::check_array_ref (location_t location, tree ref,
>  
>    /* Set to the type of the special array member for a COMPONENT_REF.  */
>    special_array_member sam{ };
> -
> +  tree afield_decl = NULL_TREE;
>    tree arg = TREE_OPERAND (ref, 0);
> -  const bool compref = TREE_CODE (arg) == COMPONENT_REF;
> -  unsigned int strict_flex_array_level = flag_strict_flex_arrays;
>  
> -  if (compref)
> +  if (TREE_CODE (arg) == COMPONENT_REF)
>      {
>        /* Try to determine special array member type for this COMPONENT_REF.  */
>        sam = component_ref_sam_type (arg);
> -      /* Get the level of strict_flex_array for this array field.  */
> -      tree afield_decl = TREE_OPERAND (arg, 1);
> -      strict_flex_array_level = strict_flex_array_level_of (afield_decl);
> +      afield_decl = TREE_OPERAND (arg, 1);
>      }
>  
>    get_up_bounds_for_array_ref (ref, &decl, &up_bound, &up_bound_p1);
> @@ -412,39 +408,15 @@ array_bounds_checker::check_array_ref (location_t location, tree ref,
>  
>        /* issue warnings for -Wstrict-flex-arrays according to the level of
>  	 flag_strict_flex_arrays.  */
> -      if (out_of_bound && warn_strict_flex_arrays)
> -      switch (strict_flex_array_level)
> -	{
> -	  case 3:
> -	    /* Issue additional warnings for trailing arrays [0].  */
> -	    if (sam == special_array_member::trail_0)
> +      if ((out_of_bound && warn_strict_flex_arrays)
> +	  && (((sam == special_array_member::trail_0)
> +		|| (sam == special_array_member::trail_1)
> +		|| (sam == special_array_member::trail_n))
> +	      && DECL_NOT_FLEXARRAY (afield_decl)))
>  	      warned = warning_at (location, OPT_Wstrict_flex_arrays,
>  				   "trailing array %qT should not be used as "
> -				   "a flexible array member for level 3",
> +				   "a flexible array member",
>  				   artype);
> -	    /* FALLTHROUGH.  */
> -	  case 2:
> -	    /* Issue additional warnings for trailing arrays [1].  */
> -	    if (sam == special_array_member::trail_1)
> -	      warned = warning_at (location, OPT_Wstrict_flex_arrays,
> -				   "trailing array %qT should not be used as "
> -				   "a flexible array member for level 2 and "
> -				   "above", artype);
> -	    /* FALLTHROUGH.  */
> -	  case 1:
> -	    /* Issue warnings for trailing arrays [n].  */
> -	    if (sam == special_array_member::trail_n)
> -	      warned = warning_at (location, OPT_Wstrict_flex_arrays,
> -				   "trailing array %qT should not be used as "
> -				   "a flexible array member for level 1 and "
> -				   "above", artype);
> -	    break;
> -	  case 0:
> -	    /* Do nothing.  */
> -	    break;
> -	  default:
> -	    gcc_unreachable ();
> -	}
>  
>        /* Avoid more warnings when checking more significant subscripts
>  	 of the same expression.  */
> diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-1.c b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-1.c
> index 65c9fec43af..fd2aacf6452 100644
> --- a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-1.c
> +++ b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-1.c
> @@ -32,7 +32,7 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_4 *trailing_flex)
>  {
>      normal->c[5] = 5; 	/*{ dg-warning "array subscript 5 is above array bounds of" } */
> -    			/*{ dg-warning "should not be used as a flexible array member for level 1 and above" "" { target *-*-* } .-1 } */
> +    			/*{ dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_1->c[2] = 2; /* { dg-bogus "array subscript " } */
>      trailing_0->c[1] = 1; /* { dg-bogus "array subscript " } */
>      trailing_flex->c[10] = 10; /* { dg-bogus "array subscript " } */
> diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-2.c b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-2.c
> index 2b5a895c598..55b7535424b 100644
> --- a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-2.c
> +++ b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-2.c
> @@ -32,9 +32,9 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_4 *trailing_flex)
>  {
>      normal->c[5] = 5; 	/*{ dg-warning "array subscript 5 is above array bounds of" } */
> -    			/*{ dg-warning "should not be used as a flexible array member for level 1 and above" "" { target *-*-* } .-1 } */
> +    			/*{ dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_1->c[2] = 2; /* { dg-warning "array subscript 2 is above array bounds of"  } */
> -    			  /* { dg-warning "should not be used as a flexible array member for level 2 and above" "" { target *-*-* } .-1 } */
> +    			  /* { dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_0->c[1] = 1; /* { dg-bogus "array subscript " } */
>      trailing_flex->c[10] = 10; /* { dg-bogus "array subscript " } */
>  
> diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-3.c b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-3.c
> index 25b903f2615..abdf8f15c78 100644
> --- a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-3.c
> +++ b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-3.c
> @@ -32,11 +32,11 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_4 *trailing_flex)
>  {
>      normal->c[5] = 5; 	/*{ dg-warning "array subscript 5 is above array bounds of" } */ 
> -    			/*{ dg-warning "should not be used as a flexible array member for level 1 and above" "" { target *-*-* } .-1 } */
> +    			/*{ dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_1->c[2] = 2; /*{ dg-warning "array subscript 2 is above array bounds of" } */ 
> -    			  /* { dg-warning "should not be used as a flexible array member for level 2 and above" "" { target *-*-* } .-1 } */
> +    			  /* { dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_0->c[1] = 1; /*{ dg-warning "array subscript 1 is outside array bounds of" } */ 
> -    			  /* { dg-warning "should not be used as a flexible array member for level 3" "" { target *-*-* } .-1 } */
> +    			  /* { dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_flex->c[10] = 10; /* { dg-bogus "array subscript" } */
>  
>  }
> diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-4.c b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-4.c
> index 5fc500a19ca..82b38ff1ad1 100644
> --- a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-4.c
> +++ b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-4.c
> @@ -32,7 +32,7 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_4 *trailing_flex)
>  {
>      normal->c[5] = 5; 	/*{ dg-warning "array subscript 5 is above array bounds of" } */
> -    			/*{ dg-warning "should not be used as a flexible array member for level 1 and above" "" { target *-*-* } .-1 } */
> +    			/*{ dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_1->c[2] = 2; /* { dg-bogus "array subscript " } */
>      trailing_0->c[1] = 1; /* { dg-bogus "array subscript " } */
>      trailing_flex->c[10] = 10; /* { dg-bogus "array subscript " } */
> diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-5.c b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-5.c
> index 30bb4ca8832..dca02288be7 100644
> --- a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-5.c
> +++ b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-5.c
> @@ -32,9 +32,9 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_4 *trailing_flex)
>  {
>      normal->c[5] = 5;   /*{ dg-warning "array subscript 5 is above array bounds of" } */
> -    			/*{ dg-warning "should not be used as a flexible array member for level 1 and above" "" { target *-*-* } .-1 } */
> +    			/*{ dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_1->c[2] = 2; /*{ dg-warning "array subscript 2 is above array bounds of" } */
> -    			  /* { dg-warning "should not be used as a flexible array member for level 2 and above" "" { target *-*-* } .-1 } */
> +    			  /* { dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_0->c[1] = 1; /* { dg-bogus "array subscript " } */
>      trailing_flex->c[10] = 10; /* { dg-bogus "array subscript " } */
>  
> diff --git a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-6.c b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-6.c
> index e847a44516e..fc9f73b4535 100644
> --- a/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-6.c
> +++ b/gcc/testsuite/gcc.dg/Warray-bounds-flex-arrays-6.c
> @@ -32,11 +32,11 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_4 *trailing_flex)
>  {
>      normal->c[5] = 5; 	/*{ dg-warning "array subscript 5 is above array bounds of" } */ 
> -    			/*{ dg-warning "should not be used as a flexible array member for level 1 and above" "" { target *-*-* } .-1 } */
> +    			/*{ dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_1->c[2] = 2; /*{ dg-warning "array subscript 2 is above array bounds of" } */
> -    			  /* { dg-warning "should not be used as a flexible array member for level 2 and above" "" { target *-*-* } .-1 } */
> +    			  /* { dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_0->c[1] = 1; /*{ dg-warning "array subscript 1 is outside array bounds of" } */
> -    			  /* { dg-warning "should not be used as a flexible array member for level 3" "" { target *-*-* } .-1 } */
> +    			  /* { dg-warning "should not be used as a flexible array member" "" { target *-*-* } .-1 } */
>      trailing_flex->c[10] = 10; /* { dg-bogus "array subscript " } */
>  
>  }
> diff --git a/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-2.c b/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-2.c
> index 2e241f96208..befc604f19b 100644
> --- a/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-2.c
> +++ b/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-2.c
> @@ -31,9 +31,9 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_3 *trailing_0,
>      struct trailing_array_4 *trailing_flex)
>  {
> -    normal->c[5] = 5; 	/*{ dg-warning "should not be used as a flexible array member for level 1 and above" } */
> -    trailing_1->c[2] = 2; /* { dg-warning "should not be used as a flexible array member for level 2 and above" } */
> -    trailing_0->c[1] = 1; /* { dg-bogus "should not be used as a flexible array member for level 2 and above" } */
> -    trailing_flex->c[10] = 10; /* { dg-bogus "should not be used as a flexible array member for level 2 and above" } */
> +    normal->c[5] = 5; 	/*{ dg-warning "should not be used as a flexible array member" } */
> +    trailing_1->c[2] = 2; /* { dg-warning "should not be used as a flexible array member" } */
> +    trailing_0->c[1] = 1; /* { dg-bogus "should not be used as a flexible array member" } */
> +    trailing_flex->c[10] = 10; /* { dg-bogus "should not be used as a flexible array member" } */
>  
>  }
> diff --git a/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-3.c b/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-3.c
> index 97eb65ba0a9..cc37a092c3e 100644
> --- a/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-3.c
> +++ b/gcc/testsuite/gcc.dg/Wstrict-flex-arrays-3.c
> @@ -31,9 +31,9 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_3 *trailing_0,
>      struct trailing_array_4 *trailing_flex)
>  {
> -    normal->c[5] = 5; 	/*{ dg-warning "should not be used as a flexible array member for level 1 and above" } */
> -    trailing_1->c[2] = 2; /* { dg-warning "should not be used as a flexible array member for level 2 and above" } */
> -    trailing_0->c[1] = 1; /* { dg-warning "should not be used as a flexible array member for level 3" } */
> -    trailing_flex->c[10] = 10; /* { dg-bogus "should not be used as a flexible array member for level 3" } */
> +    normal->c[5] = 5; 	/*{ dg-warning "should not be used as a flexible array member" } */
> +    trailing_1->c[2] = 2; /* { dg-warning "should not be used as a flexible array member" } */
> +    trailing_0->c[1] = 1; /* { dg-warning "should not be used as a flexible array member" } */
> +    trailing_flex->c[10] = 10; /* { dg-bogus "should not be used as a flexible array member" } */
>  
>  }
> diff --git a/gcc/testsuite/gcc.dg/Wstrict-flex-arrays.c b/gcc/testsuite/gcc.dg/Wstrict-flex-arrays.c
> index 110fdc72778..735b23a1dc6 100644
> --- a/gcc/testsuite/gcc.dg/Wstrict-flex-arrays.c
> +++ b/gcc/testsuite/gcc.dg/Wstrict-flex-arrays.c
> @@ -31,9 +31,9 @@ void __attribute__((__noinline__)) stuff(
>      struct trailing_array_3 *trailing_0,
>      struct trailing_array_4 *trailing_flex)
>  {
> -    normal->c[5] = 5; 	/*{ dg-warning "should not be used as a flexible array member for level 1 and above" } */
> -    trailing_1->c[2] = 2; /* { dg-bogus "should not be used as a flexible array member for level 1 and above" } */
> -    trailing_0->c[1] = 1; /* { dg-bogus "should not be used as a flexible array member for level 1 and above" } */
> -    trailing_flex->c[10] = 10; /* { dg-bogus "should not be used as a flexible array member for level 1 and above" } */
> +    normal->c[5] = 5; 	/*{ dg-warning "should not be used as a flexible array member" } */
> +    trailing_1->c[2] = 2; /* { dg-bogus "should not be used as a flexible array member" } */
> +    trailing_0->c[1] = 1; /* { dg-bogus "should not be used as a flexible array member" } */
> +    trailing_flex->c[10] = 10; /* { dg-bogus "should not be used as a flexible array member" } */
>  
>  }
> diff --git a/gcc/tree.cc b/gcc/tree.cc
> index 78b64ee98b3..7473912a065 100644
> --- a/gcc/tree.cc
> +++ b/gcc/tree.cc
> @@ -13074,38 +13074,15 @@ component_ref_size (tree ref, special_array_member *sam /* = NULL */)
>  	  || *sam == special_array_member::trail_n)
>  	return memsize;
>  
> -      /* flag_strict_flex_arrays will control how to treat
> -	 the trailing arrays as flexiable array members.  */
> -
>        tree afield_decl = TREE_OPERAND (ref, 1);
> -      unsigned int strict_flex_array_level
> -	= strict_flex_array_level_of (afield_decl);
> -
> -      switch (strict_flex_array_level)
> -	{
> -	  case 3:
> -	    /* Treaing 0-length trailing arrays as normal array.  */
> -	    if (*sam == special_array_member::trail_0)
> -	      return size_zero_node;
> -	    /* FALLTHROUGH.  */
> -	  case 2:
> -	    /* Treating 1-element trailing arrays as normal array.  */
> -	    if (*sam == special_array_member::trail_1)
> -	      return memsize;
> -	    /* FALLTHROUGH.  */
> -	  case 1:
> -	    /* Treating 2-or-more elements trailing arrays as normal
> -	       array.  */
> -	    if (*sam == special_array_member::trail_n)
> -	      return memsize;
> -	    /* FALLTHROUGH.  */
> -	  case 0:
> -	    break;
> -	  default:
> -	    gcc_unreachable ();
> -	}
> +      gcc_assert (TREE_CODE (afield_decl) == FIELD_DECL);
> +      /* if the trailing array is a not a flexible array member, treat it as
> +	 a normal array.  */
> +      if (DECL_NOT_FLEXARRAY (afield_decl)
> +	  && *sam != special_array_member::int_0)
> +	return memsize;
>  
> -	if (*sam == special_array_member::int_0)
> +      if (*sam == special_array_member::int_0)
>  	  memsize = NULL_TREE;
>  
>        /* For a reference to a flexible array member of a union
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)

      reply	other threads:[~2023-01-13  7:00 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-12 23:04 [PATCH 0/1] " Qing Zhao
2023-01-12 23:04 ` [PATCH 1/1] " Qing Zhao
2023-01-13  7:00   ` Richard Biener [this message]

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