Looks good!
(not sure if I am a proper reviewer though)
--kcc
On Thu, Nov 22, 2012 at 3:07 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> This patch adds the no_address_safety_analysis attribute. Tested on
> x86_64-linux, ok for trunk?
>
> 2012-11-22 Jakub Jelinek <ja...@redhat.com>
>
> PR sanitizer/55435
> * c-common.c (handle_no_address_safety_analysis_attribute): New
> function.
> (c_common_attribute_table): Add no_address_safety_analysis.
>
> * asan.c (gate_asan): Don't instrument functions with
> no_address_safety_analysis attribute.
> (gate_asan_O0): Use !optimize && gate_asan ().
> * doc/extend.texi (no_address_safety_analysis): Document new
> function attribute.
>
> * c-c++-common/asan/attrib-1.c: New test.
>
> --- gcc/c-family/c-common.c.jj 2012-11-19 14:41:10.000000000 +0100
> +++ gcc/c-family/c-common.c 2012-11-22 11:51:48.053996443 +0100
> @@ -309,6 +309,8 @@ static tree handle_common_attribute (tre
> static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
> static tree handle_hot_attribute (tree *, tree, tree, int, bool *);
> static tree handle_cold_attribute (tree *, tree, tree, int, bool *);
> +static tree handle_no_address_safety_analysis_attribute (tree *, tree, tree,
> + int, bool *);
> static tree handle_noinline_attribute (tree *, tree, tree, int, bool *);
> static tree handle_noclone_attribute (tree *, tree, tree, int, bool *);
> static tree handle_leaf_attribute (tree *, tree, tree, int, bool *);
> @@ -711,6 +713,10 @@ const struct attribute_spec c_common_att
> handle_cold_attribute, false },
> { "hot", 0, 0, true, false, false,
> handle_hot_attribute, false },
> + { "no_address_safety_analysis",
> + 0, 0, true, false, false,
> + handle_no_address_safety_analysis_attribute,
> + false },
> { "warning", 1, 1, true, false, false,
> handle_error_attribute, false },
> { "error", 1, 1, true, false, false,
> @@ -6477,6 +6483,22 @@ handle_cold_attribute (tree *node, tree
> {
> warning (OPT_Wattributes, "%qE attribute ignored", name);
> *no_add_attrs = true;
> + }
> +
> + return NULL_TREE;
> +}
> +
> +/* Handle a "no_address_safety_analysis" attribute; arguments as in
> + struct attribute_spec.handler. */
> +
> +static tree
> +handle_no_address_safety_analysis_attribute (tree *node, tree name, tree,
> int,
> + bool *no_add_attrs)
> +{
> + if (TREE_CODE (*node) != FUNCTION_DECL)
> + {
> + warning (OPT_Wattributes, "%qE attribute ignored", name);
> + *no_add_attrs = true;
> }
>
> return NULL_TREE;
> --- gcc/asan.c.jj 2012-11-19 14:41:20.000000000 +0100
> +++ gcc/asan.c 2012-11-22 11:35:47.310489415 +0100
> @@ -1587,7 +1587,9 @@ asan_instrument (void)
> static bool
> gate_asan (void)
> {
> - return flag_asan != 0;
> + return flag_asan != 0
> + && !lookup_attribute ("no_address_safety_analysis",
> + DECL_ATTRIBUTES (current_function_decl));
> }
>
> struct gimple_opt_pass pass_asan =
> @@ -1614,7 +1616,7 @@ struct gimple_opt_pass pass_asan =
> static bool
> gate_asan_O0 (void)
> {
> - return flag_asan != 0 && !optimize;
> + return !optimize && gate_asan ();
> }
>
> struct gimple_opt_pass pass_asan_O0 =
> --- gcc/doc/extend.texi.jj 2012-11-19 14:41:08.000000000 +0100
> +++ gcc/doc/extend.texi 2012-11-22 11:52:20.913814831 +0100
> @@ -2130,10 +2130,11 @@ attributes are currently defined for fun
> @code{weak}, @code{malloc}, @code{alias}, @code{ifunc},
> @code{warn_unused_result}, @code{nonnull}, @code{gnu_inline},
> @code{externally_visible}, @code{hot}, @code{cold}, @code{artificial},
> -@code{error} and @code{warning}. Several other attributes are defined
> -for functions on particular target systems. Other attributes,
> -including @code{section} are supported for variables declarations
> -(@pxref{Variable Attributes}) and for types (@pxref{Type Attributes}).
> +@code{no_address_safety_analysis}, @code{error} and @code{warning}.
> +Several other attributes are defined for functions on particular
> +target systems. Other attributes, including @code{section} are
> +supported for variables declarations (@pxref{Variable Attributes})
> +and for types (@pxref{Type Attributes}).
>
> GCC plugins may provide their own attributes.
>
> @@ -3416,6 +3417,12 @@ with computed goto or @code{asm goto}.
> The @code{cold} attribute on labels is not implemented in GCC versions
> earlier than 4.8.
>
> +@item no_address_safety_analysis
> +@cindex @code{no_address_safety_analysis} function attribute
> +The @code{no_address_safety_analysis} attribute on functions is used
> +to inform the compiler that it should not instrument memory accesses
> +in the function when compiling with the @option{-fsanitize=address} option.
> +
> @item regparm (@var{number})
> @cindex @code{regparm} attribute
> @cindex functions that are passed arguments in registers on the 386
> --- gcc/testsuite/c-c++-common/asan/attrib-1.c.jj 2012-11-22
> 11:43:58.356674747 +0100
> +++ gcc/testsuite/c-c++-common/asan/attrib-1.c 2012-11-22 11:59:49.213328881
> +0100
> @@ -0,0 +1,34 @@
> +/* PR sanitizer/55435 */
> +/* { dg-do compile } */
> +
> +__attribute__((no_address_safety_analysis)) int
> +f1 (int *p, int *q)
> +{
> + *p = 42;
> + return *q;
> +}
> +
> +void f2 (char *);
> +void f2 (char *) __attribute__((no_address_safety_analysis));
> +void f2 (char *) __attribute__((no_address_safety_analysis));
> +void f2 (char *);
> +
> +void
> +f2 (char *p)
> +{
> + *p = 42;
> +}
> +
> +void f3 (short *);
> +__typeof (f3) f3 __attribute__((__no_address_safety_analysis__));
> +
> +void
> +f3 (short *p)
> +{
> + *p = 42;
> +}
> +
> +int v __attribute__((no_address_safety_analysis)); /* { dg-warning
> "attribute ignored" } */
> +
> +/* { dg-final { scan-assembler-not "__asan_report_store" } } */
> +/* { dg-final { scan-assembler-not "__asan_report_load" } } */
>
> Jakub
