diff options
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/c-family/c-common.c | 38 | ||||
| -rw-r--r-- | gcc/doc/extend.texi | 47 |
3 files changed, 87 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6756d10..dc9bbf8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2013-10-30 Ilya Enkovich <ilya.enkovich@intel.com> + + * c-family/c-common.c (handle_bnd_variable_size_attribute): New. + (handle_bnd_legacy): New. + (c_common_attribute_table): Add bnd_variable_size and bnd_legacy. + * doc/extend.texi: Document bnd_variable_size and bnd_legacy + attributes. + 2013-10-29 Ilya Enkovich <ilya.enkovich@intel.com> * builtin-types.def (BT_FN_VOID_CONST_PTR): New. diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 6473168..b01b9d0 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -375,6 +375,8 @@ static tree handle_omp_declare_simd_attribute (tree *, tree, tree, int, bool *); static tree handle_omp_declare_target_attribute (tree *, tree, tree, int, bool *); +static tree handle_bnd_variable_size_attribute (tree *, tree, tree, int, bool *); +static tree handle_bnd_legacy (tree *, tree, tree, int, bool *); static void check_function_nonnull (tree, int, tree *); static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT); @@ -759,6 +761,10 @@ const struct attribute_spec c_common_attribute_table[] = handle_omp_declare_simd_attribute, false }, { "omp declare target", 0, 0, true, false, false, handle_omp_declare_target_attribute, false }, + { "bnd_variable_size", 0, 0, true, false, false, + handle_bnd_variable_size_attribute, false }, + { "bnd_legacy", 0, 0, true, false, false, + handle_bnd_legacy, false }, { NULL, 0, 0, false, false, false, NULL, false } }; @@ -8018,6 +8024,38 @@ handle_fnspec_attribute (tree *node ATTRIBUTE_UNUSED, tree ARG_UNUSED (name), return NULL_TREE; } +/* Handle a "bnd_variable_size" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_bnd_variable_size_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) != FIELD_DECL) + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "bnd_legacy" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_bnd_legacy (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) != FUNCTION_DECL) + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + /* Handle a "warn_unused" attribute; arguments as in struct attribute_spec.handler. */ diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 8ca3137..1d52e42 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -2138,7 +2138,7 @@ attributes are currently defined for functions on all targets: @code{returns_nonnull}, @code{gnu_inline}, @code{externally_visible}, @code{hot}, @code{cold}, @code{artificial}, @code{no_sanitize_address}, @code{no_address_safety_analysis}, -@code{no_sanitize_undefined}, +@code{no_sanitize_undefined}, @code{bnd_legacy}, @code{error} and @code{warning}. Several other attributes are defined for functions on particular target systems. Other attributes, including @code{section} are @@ -3549,6 +3549,12 @@ The @code{no_sanitize_undefined} attribute on functions is used to inform the compiler that it should not check for undefined behavior in the function when compiling with the @option{-fsanitize=undefined} option. +@item bnd_legacy +@cindex @code{bnd_legacy} function attribute +The @code{bnd_legacy} attribute on functions is used to inform +compiler that function should not be instrumented when compiled +with @option{-fcheck-pointers} option. + @item regparm (@var{number}) @cindex @code{regparm} attribute @cindex functions that are passed arguments in registers on the 386 @@ -5321,12 +5327,12 @@ placed in either the @code{.bss_below100} section or the The keyword @code{__attribute__} allows you to specify special attributes of @code{struct} and @code{union} types when you define such types. This keyword is followed by an attribute specification -inside double parentheses. Seven attributes are currently defined for +inside double parentheses. Eight attributes are currently defined for types: @code{aligned}, @code{packed}, @code{transparent_union}, -@code{unused}, @code{deprecated}, @code{visibility}, and -@code{may_alias}. Other attributes are defined for functions -(@pxref{Function Attributes}) and for variables (@pxref{Variable -Attributes}). +@code{unused}, @code{deprecated}, @code{visibility}, @code{may_alias} +and @code{bnd_variable_size}. Other attributes are defined for +functions (@pxref{Function Attributes}) and for variables +(@pxref{Variable Attributes}). You may also specify any one of these attributes with @samp{__} preceding and following its keyword. This allows you to use these @@ -5618,6 +5624,35 @@ and caught in another, the class must have default visibility. Otherwise the two shared objects are unable to use the same typeinfo node and exception handling will break. +@item bnd_variable_size +When applied to a structure field, this attribute tells Pointer +Bounds Checker that the size of this field should not be computed +using static type information. It may be used to mark variable +sized static array fields placed at the end of a structure. + +@smallexample +struct S +@{ + int size; + char data[1]; +@} +S *p = (S *)malloc (sizeof(S) + 100); +p->data[10] = 0; //Bounds violation +@end smallexample + +By using an attribute for a field we may avoid bound violation +we most probably do not want to see: + +@smallexample +struct S +@{ + int size; + char data[1] __attribute__((bnd_variable_size)); +@} +S *p = (S *)malloc (sizeof(S) + 100); +p->data[10] = 0; //OK +@end smallexample + @end table To specify multiple attributes, separate them by commas within the |