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
