Re: [PATCH, CHKP, PR64363] Don't instrument functions we cannot copy

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

On Fri, Jan 16, 2015 at 11:41 AM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> On 15 Jan 15:03, Richard Biener wrote:
>> On Thu, Jan 15, 2015 at 2:51 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>> > 2015-01-15 16:07 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
>> >> On Thu, Jan 15, 2015 at 12:46 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>> >>> Hi,
>> >>>
>> >>> This patch is to fix https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64363.  Patch disables instrumentation for functions we cannot clone correctly due to labels.
>> >>>
>> >>> Bootstrapped and checked on x86_64-unknown-linux-gnu.  OK for trunk?
>> >>
>> >>           {
>> >> +             clone->remove_callees ();
>> >> +             clone->remove_all_references ();
>> >>
>> >> this looks like a spurious change?
>> >
>> > Seems bogus thunk creation here wasn't triggered before but this test
>> > revealed it in addition to labels issue.
>> >
>> >>
>> >> +             std::string msg = "function cannot be instrumented: ";
>> >> +             msg += reason;
>> >> +             warning (OPT_Wchkp, msg.c_str (), node->decl);
>> >>
>> >> ick - please don't use std::string.  SImply do
>> >>
>> >>  warning (OPT_Wchkp, "function cannot be instrumented: %s", node->decl, reason);
>> >
>> > reason string has "%q+F" inside and therefore string concatenation is required.
>>
>> Then use
>>
>>     if (warning (OPT_Wchkp, "function cannot be instrumented"))
>>       inform (reason);
>>
>> Richard.
>>
>> > Thanks,
>> > Ilya
>> >
>> >>
>
> Here is a version with warning + inform.  Thanks for review!

Ok.

Thanks,
Richard.

> Ilya
> --
> gcc/
>
> 2015-01-16  Ilya Enkovich  <ilya.enkovich@intel.com>
>
>         PR target/64363
>         * ipa-chkp.h (chkp_instrumentable_p): New.
>         * ipa-chkp.c: Include tree-inline.h.
>         (chkp_instrumentable_p): New.
>         (chkp_maybe_create_clone): Use chkp_instrumentable_p.
>         Fix processing of not instrumentable functions.
>         (chkp_versioning): Use chkp_instrumentable_p. Warn about
>         not instrumentable functions.
>         * tree-chkp.c (chkp_add_bounds_to_call_stmt): Use
>         chkp_instrumentable_p.
>         * tree-inline.h (copy_forbidden): New.
>         * tree-inline.c (copy_forbidden): Not static anymore.
>
> gcc/testsuite/
>
> 2015-01-16  Ilya Enkovich  <ilya.enkovich@intel.com>
>
>         PR target/64363
>         * gcc.target/i386/chkp-label-address.c: New.
>
>
> diff --git a/gcc/ipa-chkp.c b/gcc/ipa-chkp.c
> index 30d511d..8e6612e 100644
> --- a/gcc/ipa-chkp.c
> +++ b/gcc/ipa-chkp.c
> @@ -50,6 +50,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "lto-streamer.h"
>  #include "cgraph.h"
>  #include "tree-chkp.h"
> +#include "tree-inline.h"
>  #include "ipa-chkp.h"
>
>  /*  Pointer Bounds Checker has two IPA passes to support code instrumentation.
> @@ -401,6 +402,18 @@ chkp_maybe_clone_builtin_fndecl (tree fndecl)
>    return clone;
>  }
>
> +/* Return 1 if function FNDECL should be instrumented.  */
> +
> +bool
> +chkp_instrumentable_p (tree fndecl)
> +{
> +  struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
> +  return (!lookup_attribute ("bnd_legacy", DECL_ATTRIBUTES (fndecl))
> +         && (!flag_chkp_instrument_marked_only
> +             || lookup_attribute ("bnd_instrument", DECL_ATTRIBUTES (fndecl)))
> +         && (!fn || !copy_forbidden (fn, fndecl)));
> +}
> +
>  /* Return clone created for instrumentation of NODE or NULL.  */
>
>  cgraph_node *
> @@ -483,10 +496,10 @@ chkp_maybe_create_clone (tree fndecl)
>         {
>           /* If function will not be instrumented, then it's instrumented
>              version is a thunk for the original.  */
> -         if (lookup_attribute ("bnd_legacy", DECL_ATTRIBUTES (fndecl))
> -             || (flag_chkp_instrument_marked_only
> -                 && !lookup_attribute ("bnd_instrument", DECL_ATTRIBUTES (fndecl))))
> +         if (!chkp_instrumentable_p (fndecl))
>             {
> +             clone->remove_callees ();
> +             clone->remove_all_references ();
>               clone->thunk.thunk_p = true;
>               clone->thunk.add_pointer_bounds_args = true;
>               clone->create_edge (node, NULL, 0, CGRAPH_FREQ_BASE);
> @@ -532,7 +545,8 @@ chkp_maybe_create_clone (tree fndecl)
>
>        /* Clone all thunks.  */
>        for (e = node->callers; e; e = e->next_caller)
> -       if (e->caller->thunk.thunk_p)
> +       if (e->caller->thunk.thunk_p
> +           && !e->caller->thunk.add_pointer_bounds_args)
>           {
>             struct cgraph_node *thunk
>               = chkp_maybe_create_clone (e->caller->decl);
> @@ -578,6 +592,7 @@ static unsigned int
>  chkp_versioning (void)
>  {
>    struct cgraph_node *node;
> +  const char *reason;
>
>    bitmap_obstack_initialize (NULL);
>
> @@ -587,14 +602,20 @@ chkp_versioning (void)
>           && !node->instrumented_version
>           && !node->alias
>           && !node->thunk.thunk_p
> -         && !lookup_attribute ("bnd_legacy", DECL_ATTRIBUTES (node->decl))
> -         && (!flag_chkp_instrument_marked_only
> -             || lookup_attribute ("bnd_instrument",
> -                                  DECL_ATTRIBUTES (node->decl)))
>           && (!DECL_BUILT_IN (node->decl)
>               || (DECL_BUILT_IN_CLASS (node->decl) == BUILT_IN_NORMAL
>                   && DECL_FUNCTION_CODE (node->decl) < BEGIN_CHKP_BUILTINS)))
> -       chkp_maybe_create_clone (node->decl);
> +       {
> +         if (chkp_instrumentable_p (node->decl))
> +           chkp_maybe_create_clone (node->decl);
> +         else if ((reason = copy_forbidden (DECL_STRUCT_FUNCTION (node->decl),
> +                                            node->decl)))
> +           {
> +             if (warning_at (DECL_SOURCE_LOCATION (node->decl), OPT_Wchkp,
> +                             "function cannot be instrumented"))
> +               inform (DECL_SOURCE_LOCATION (node->decl), reason, node->decl);
> +           }
> +       }
>      }
>
>    /* Mark all aliases and thunks of functions with no instrumented
> diff --git a/gcc/ipa-chkp.h b/gcc/ipa-chkp.h
> index b087227..6708fe9 100644
> --- a/gcc/ipa-chkp.h
> +++ b/gcc/ipa-chkp.h
> @@ -23,5 +23,6 @@ along with GCC; see the file COPYING3.  If not see
>  extern tree chkp_copy_function_type_adding_bounds (tree orig_type);
>  extern tree chkp_maybe_clone_builtin_fndecl (tree fndecl);
>  extern cgraph_node *chkp_maybe_create_clone (tree fndecl);
> +extern bool chkp_instrumentable_p (tree fndecl);
>
>  #endif /* GCC_IPA_CHKP_H */
> diff --git a/gcc/testsuite/gcc.target/i386/chkp-label-address.c b/gcc/testsuite/gcc.target/i386/chkp-label-address.c
> new file mode 100644
> index 0000000..05963e2
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/chkp-label-address.c
> @@ -0,0 +1,24 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target mpx } */
> +/* { dg-options "-fcheck-pointer-bounds -mmpx -O2 -Wchkp" } */
> +
> +#include <stdio.h>
> +
> +static int f1 () /* { dg-warning "function cannot be instrumented" "" } */
> +{
> +  static int array = &&label_B - &&label_A;
> +
> + label_A:
> +
> +  printf ("%d\n", array);
> +
> + label_B:
> +
> +  return 0;
> +}
> +
> +int f2 (int i)
> +{
> +  printf ("%d\n", i);
> +  return f1 ();
> +}
> diff --git a/gcc/tree-chkp.c b/gcc/tree-chkp.c
> index c606040..f2e8c56 100644
> --- a/gcc/tree-chkp.c
> +++ b/gcc/tree-chkp.c
> @@ -1672,9 +1672,8 @@ chkp_add_bounds_to_call_stmt (gimple_stmt_iterator *gsi)
>        && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_OBJECT_SIZE)
>      return;
>
> -  /* Do nothing for calls to legacy functions.  */
> -  if (fndecl
> -      && lookup_attribute ("bnd_legacy", DECL_ATTRIBUTES (fndecl)))
> +  /* Do nothing for calls to not instrumentable functions.  */
> +  if (fndecl && !chkp_instrumentable_p (fndecl))
>      return;
>
>    /* Ignore CHKP_INIT_PTR_BOUNDS, CHKP_NULL_PTR_BOUNDS
> diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
> index 4a47fd2..8dbb55f 100644
> --- a/gcc/tree-inline.c
> +++ b/gcc/tree-inline.c
> @@ -3532,7 +3532,7 @@ has_label_address_in_static_1 (tree *nodep, int *walk_subtrees, void *fnp)
>  /* Determine if the function can be copied.  If so return NULL.  If
>     not return a string describng the reason for failure.  */
>
> -static const char *
> +const char *
>  copy_forbidden (struct function *fun, tree fndecl)
>  {
>    const char *reason = fun->cannot_be_copied_reason;
> diff --git a/gcc/tree-inline.h b/gcc/tree-inline.h
> index 985d83b..f8b2ebf 100644
> --- a/gcc/tree-inline.h
> +++ b/gcc/tree-inline.h
> @@ -234,6 +234,7 @@ extern tree remap_type (tree type, copy_body_data *id);
>  extern gimple_seq copy_gimple_seq_and_replace_locals (gimple_seq seq);
>  extern bool debug_find_tree (tree, tree);
>  extern tree copy_fn (tree, tree&, tree&);
> +extern const char *copy_forbidden (struct function *fun, tree fndecl);
>
>  /* This is in tree-inline.c since the routine uses
>     data structures from the inliner.  */