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

[Ilya Enkovich <enkovich dot gnu at gmail dot com>]

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.

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;