Re: [PATCH, MPX, 2/X] Pointers Checker [8/25] Languages support

[Richard Biener <richard dot guenther at gmail dot com>]

On Tue, Nov 5, 2013 at 2:20 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> 2013/11/5 Richard Biener <richard.guenther@gmail.com>:
>> On Tue, Nov 5, 2013 at 2:02 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>>> 2013/11/4 Richard Biener <richard.guenther@gmail.com>:
>>>> On Thu, Oct 31, 2013 at 10:11 AM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>>>>> Hi,
>>>>>
>>>>> This patch adds support Pointer Bounds Checker into c-family and LTO front-ends.  The main purpose of changes in front-end is to register all statically initialized objects for checker.  We also need to register such objects created by compiler.
>>>
>>> LTO is quite specific front-end.  For LTO Pointer Bounds Checker
>>> support macro just means it allows instrumented code as input because
>>> all instrumentation is performed before code is streamed out for LTO.
>>
>> But your patch doesn't even make use of the langhook...
>
> Use of langhook is in previous patch
> (http://gcc.gnu.org/ml/gcc-patches/2013-10/msg02408.html). Here is
> it's part:
>
> diff --git a/gcc/toplev.c b/gcc/toplev.c
> index db269b7..0eaf081 100644
> --- a/gcc/toplev.c
> +++ b/gcc/toplev.c
> @@ -1282,6 +1282,15 @@ process_options (void)
>            "and -ftree-loop-linear)");
>  #endif
>
> +  if (flag_check_pointer_bounds)
> +    {
> +      if (targetm.chkp_bound_mode () == VOIDmode)
> +       error ("-fcheck-pointers is not supported for this target");
> +
> +      if (!lang_hooks.chkp_supported)
> +       flag_check_pointer_bounds = 0;
> +    }
> +
>    /* One region RA really helps to decrease the code size.  */
>    if (flag_ira_region == IRA_REGION_AUTODETECT)
>      flag_ira_region
>
> If we try to use -fcheck-pointers -flto for some unsupported language,
> code will not be instrumented.

What's the reason to have unsupported languages?

Richard.

> Ilya
>
>>
>> Richard.
>>
>>> Ilya
>>>
>>>>
>>>> You define CHKP as supported in LTO.  That means it has to be supported
>>>> for all languages and thus you should drop the langhook.
>>>>
>>>> Richard.
>>>>
>>>>> Thanks,
>>>>> Ilya
>>>>> --
>>>>>
>>>>> gcc/
>>>>>
>>>>> 2013-10-29  Ilya Enkovich  <ilya.enkovich@intel.com>
>>>>>
>>>>>         * c/c-lang.c (LANG_HOOKS_CHKP_SUPPORTED): New.
>>>>>         * cp/cp-lang.c (LANG_HOOKS_CHKP_SUPPORTED): New.
>>>>>         * objc/objc-lang.c (LANG_HOOKS_CHKP_SUPPORTED): New.
>>>>>         * objcp/objcp-lang.c (LANG_HOOKS_CHKP_SUPPORTED): New.
>>>>>         * lto/lto-lang.c (LANG_HOOKS_CHKP_SUPPORTED): New.
>>>>>         * c/c-parser.c (c_parser_declaration_or_fndef): Register statically
>>>>>         initialized decls in Pointer Bounds Checker.
>>>>>         * cp/decl.c (cp_finish_decl): Likewise.
>>>>>         * gimplify.c (gimplify_init_constructor): Likewise.
>>>>>
>>>>>
>>>>> diff --git a/gcc/c/c-lang.c b/gcc/c/c-lang.c
>>>>> index 614c46d..a32bc6b 100644
>>>>> --- a/gcc/c/c-lang.c
>>>>> +++ b/gcc/c/c-lang.c
>>>>> @@ -43,6 +43,8 @@ enum c_language_kind c_language = clk_c;
>>>>>  #define LANG_HOOKS_INIT c_objc_common_init
>>>>>  #undef LANG_HOOKS_INIT_TS
>>>>>  #define LANG_HOOKS_INIT_TS c_common_init_ts
>>>>> +#undef LANG_HOOKS_CHKP_SUPPORTED
>>>>> +#define LANG_HOOKS_CHKP_SUPPORTED true
>>>>>
>>>>>  /* Each front end provides its own lang hook initializer.  */
>>>>>  struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
>>>>> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
>>>>> index 9ccae3b..65d83c8 100644
>>>>> --- a/gcc/c/c-parser.c
>>>>> +++ b/gcc/c/c-parser.c
>>>>> @@ -1682,6 +1682,12 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fndef_ok,
>>>>>                   maybe_warn_string_init (TREE_TYPE (d), init);
>>>>>                   finish_decl (d, init_loc, init.value,
>>>>>                                init.original_type, asm_name);
>>>>> +
>>>>> +                 /* Register all decls with initializers in Pointer
>>>>> +                    Bounds Checker to generate required static bounds
>>>>> +                    initializers.  */
>>>>> +                 if (DECL_INITIAL (d) != error_mark_node)
>>>>> +                   chkp_register_var_initializer (d);
>>>>>                 }
>>>>>             }
>>>>>           else
>>>>> diff --git a/gcc/cp/cp-lang.c b/gcc/cp/cp-lang.c
>>>>> index a7fa8e4..6d138bd 100644
>>>>> --- a/gcc/cp/cp-lang.c
>>>>> +++ b/gcc/cp/cp-lang.c
>>>>> @@ -81,6 +81,8 @@ static tree get_template_argument_pack_elems_folded (const_tree);
>>>>>  #define LANG_HOOKS_EH_PERSONALITY cp_eh_personality
>>>>>  #undef LANG_HOOKS_EH_RUNTIME_TYPE
>>>>>  #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
>>>>> +#undef LANG_HOOKS_CHKP_SUPPORTED
>>>>> +#define LANG_HOOKS_CHKP_SUPPORTED true
>>>>>
>>>>>  /* Each front end provides its own lang hook initializer.  */
>>>>>  struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
>>>>> diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
>>>>> index 1e92f2a..db40e75 100644
>>>>> --- a/gcc/cp/decl.c
>>>>> +++ b/gcc/cp/decl.c
>>>>> @@ -6379,6 +6379,12 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
>>>>>              the class specifier.  */
>>>>>           if (!DECL_EXTERNAL (decl))
>>>>>             var_definition_p = true;
>>>>> +
>>>>> +         /* If var has initilizer then we need to register it in
>>>>> +            Pointer Bounds Checker to generate static bounds initilizer
>>>>> +            if required.  */
>>>>> +         if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
>>>>> +           chkp_register_var_initializer (decl);
>>>>>         }
>>>>>        /* If the variable has an array type, lay out the type, even if
>>>>>          there is no initializer.  It is valid to index through the
>>>>> diff --git a/gcc/gimplify.c b/gcc/gimplify.c
>>>>> index 4f52c27..503450f 100644
>>>>> --- a/gcc/gimplify.c
>>>>> +++ b/gcc/gimplify.c
>>>>> @@ -4111,6 +4111,11 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
>>>>>
>>>>>                 walk_tree (&ctor, force_labels_r, NULL, NULL);
>>>>>                 ctor = tree_output_constant_def (ctor);
>>>>> +
>>>>> +               /* We need to register created constant object to
>>>>> +                  initialize bounds for pointers in it.  */
>>>>> +               chkp_register_var_initializer (ctor);
>>>>> +
>>>>>                 if (!useless_type_conversion_p (type, TREE_TYPE (ctor)))
>>>>>                   ctor = build1 (VIEW_CONVERT_EXPR, type, ctor);
>>>>>                 TREE_OPERAND (*expr_p, 1) = ctor;
>>>>> diff --git a/gcc/lto/lto-lang.c b/gcc/lto/lto-lang.c
>>>>> index 0fa0fc9..b6073d9 100644
>>>>> --- a/gcc/lto/lto-lang.c
>>>>> +++ b/gcc/lto/lto-lang.c
>>>>> @@ -1278,6 +1278,8 @@ static void lto_init_ts (void)
>>>>>
>>>>>  #undef LANG_HOOKS_INIT_TS
>>>>>  #define LANG_HOOKS_INIT_TS lto_init_ts
>>>>> +#undef LANG_HOOKS_CHKP_SUPPORTED
>>>>> +#define LANG_HOOKS_CHKP_SUPPORTED true
>>>>>
>>>>>  struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
>>>>>
>>>>> diff --git a/gcc/objc/objc-lang.c b/gcc/objc/objc-lang.c
>>>>> index bc0008b..5e7e43b 100644
>>>>> --- a/gcc/objc/objc-lang.c
>>>>> +++ b/gcc/objc/objc-lang.c
>>>>> @@ -49,6 +49,8 @@ enum c_language_kind c_language = clk_objc;
>>>>>  #define LANG_HOOKS_GIMPLIFY_EXPR objc_gimplify_expr
>>>>>  #undef LANG_HOOKS_INIT_TS
>>>>>  #define LANG_HOOKS_INIT_TS objc_common_init_ts
>>>>> +#undef LANG_HOOKS_CHKP_SUPPORTED
>>>>> +#define LANG_HOOKS_CHKP_SUPPORTED true
>>>>>
>>>>>  /* Each front end provides its own lang hook initializer.  */
>>>>>  struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
>>>>> diff --git a/gcc/objcp/objcp-lang.c b/gcc/objcp/objcp-lang.c
>>>>> index f9b126f..0bb80eb 100644
>>>>> --- a/gcc/objcp/objcp-lang.c
>>>>> +++ b/gcc/objcp/objcp-lang.c
>>>>> @@ -46,6 +46,8 @@ static void objcxx_init_ts (void);
>>>>>  #define LANG_HOOKS_GIMPLIFY_EXPR objc_gimplify_expr
>>>>>  #undef LANG_HOOKS_INIT_TS
>>>>>  #define LANG_HOOKS_INIT_TS objcxx_init_ts
>>>>> +#undef LANG_HOOKS_CHKP_SUPPORTED
>>>>> +#define LANG_HOOKS_CHKP_SUPPORTED true
>>>>>
>>>>>  /* Each front end provides its own lang hook initializer.  */
>>>>>  struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;