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

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

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!

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.  */