Re: [PATCH, Pointer Bounds Checker 1/x] Pointer bounds type and mode

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

On Tue, May 6, 2014 at 2:10 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> 2014-04-16 15:00 GMT+04:00 Ilya Enkovich <enkovich.gnu@gmail.com>:
>> Hi,
>>
>> This patch restarts the series for introducing Pointer Bounds Checker instrumentation and supporting Intel Memory Protection Extension (MPX) technology.  Detailed description is on GCC Wiki page: http://gcc.gnu.org/wiki/Intel%20MPX%20support%20in%20the%20GCC%20compiler.
>>
>> The first patch introduces pointer bounds type and mode.  It was approved earlier for 4.9 and had no significant changes since then.  I'll assume patch is OK if no objections arise.
>>
>> Patch was bootstrapped and tested for linux-x86_64.
>>
>> Thanks,
>> Ilya
>> --
>> gcc/
>>
>> 2014-04-16  Ilya Enkovich  <ilya.enkovich@intel.com>
>>
>>         * mode-classes.def (MODE_POINTER_BOUNDS): New.
>>         * tree.def (POINTER_BOUNDS_TYPE): New.
>>         * genmodes.c (complete_mode): Support MODE_POINTER_BOUNDS.
>>         (POINTER_BOUNDS_MODE): New.
>>         (make_pointer_bounds_mode): New.
>>         * machmode.h (POINTER_BOUNDS_MODE_P): New.
>>         * stor-layout.c (int_mode_for_mode): Support MODE_POINTER_BOUNDS.
>>         (layout_type): Support POINTER_BOUNDS_TYPE.
>>         * tree-pretty-print.c (dump_generic_node): Support POINTER_BOUNDS_TYPE.
>>         * tree.c (build_int_cst_wide): Support POINTER_BOUNDS_TYPE.
>>         (type_contains_placeholder_1): Likewise.
>>         * tree.h (POINTER_BOUNDS_TYPE_P): New.
>>         * varasm.c (output_constant): Support POINTER_BOUNDS_TYPE.
>>         * doc/rtl.texi (MODE_POINTER_BOUNDS): New.
>>
>>
>> diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
>> index 20b7187..3a1014d 100644
>> --- a/gcc/doc/rtl.texi
>> +++ b/gcc/doc/rtl.texi
>> @@ -1382,6 +1382,12 @@ any @code{CC_MODE} modes listed in the @file{@var{machine}-modes.def}.
>>  @xref{Jump Patterns},
>>  also see @ref{Condition Code}.
>>
>> +@findex MODE_POINTER_BOUNDS
>> +@item MODE_POINTER_BOUNDS
>> +Pointer bounds modes.  Used to represent values of pointer bounds type.
>> +Operations in these modes may be executed as NOPs depending on hardware
>> +features and environment setup.
>> +
>>  @findex MODE_RANDOM
>>  @item MODE_RANDOM
>>  This is a catchall mode class for modes which don't fit into the above
>> diff --git a/gcc/genmodes.c b/gcc/genmodes.c
>> index 8cc3cde..9d0b413 100644
>> --- a/gcc/genmodes.c
>> +++ b/gcc/genmodes.c
>> @@ -333,6 +333,7 @@ complete_mode (struct mode_data *m)
>>        break;
>>
>>      case MODE_INT:
>> +    case MODE_POINTER_BOUNDS:
>>      case MODE_FLOAT:
>>      case MODE_DECIMAL_FLOAT:
>>      case MODE_FRACT:
>> @@ -534,6 +535,19 @@ make_special_mode (enum mode_class cl, const char *name,
>>    new_mode (cl, name, file, line);
>>  }
>>
>> +#define POINTER_BOUNDS_MODE(N, Y) \
>> +  make_pointer_bounds_mode (#N, Y, __FILE__, __LINE__)
>> +
>> +static void ATTRIBUTE_UNUSED
>> +make_pointer_bounds_mode (const char *name,
>> +                         unsigned int bytesize,
>> +                         const char *file, unsigned int line)
>> +{
>> +  struct mode_data *m = new_mode (MODE_POINTER_BOUNDS, name, file, line);
>> +  m->bytesize = bytesize;
>> +}
>> +
>> +
>>  #define INT_MODE(N, Y) FRACTIONAL_INT_MODE (N, -1U, Y)
>>  #define FRACTIONAL_INT_MODE(N, B, Y) \
>>    make_int_mode (#N, B, Y, __FILE__, __LINE__)
>> diff --git a/gcc/machmode.h b/gcc/machmode.h
>> index bc5d901..cbe5042 100644
>> --- a/gcc/machmode.h
>> +++ b/gcc/machmode.h
>> @@ -174,6 +174,9 @@ extern const unsigned char mode_class[NUM_MACHINE_MODES];
>>     || CLASS == MODE_ACCUM                      \
>>     || CLASS == MODE_UACCUM)
>>
>> +#define POINTER_BOUNDS_MODE_P(MODE)      \
>> +  (GET_MODE_CLASS (MODE) == MODE_POINTER_BOUNDS)
>> +
>>  /* Get the size in bytes and bits of an object of mode MODE.  */
>>
>>  extern CONST_MODE_SIZE unsigned char mode_size[NUM_MACHINE_MODES];
>> diff --git a/gcc/mode-classes.def b/gcc/mode-classes.def
>> index 9c6a8bb..b645484 100644
>> --- a/gcc/mode-classes.def
>> +++ b/gcc/mode-classes.def
>> @@ -22,6 +22,7 @@ along with GCC; see the file COPYING3.  If not see
>>    DEF_MODE_CLASS (MODE_CC),            /* condition code in a register */ \
>>    DEF_MODE_CLASS (MODE_INT),           /* integer */                      \
>>    DEF_MODE_CLASS (MODE_PARTIAL_INT),   /* integer with padding bits */    \
>> +  DEF_MODE_CLASS (MODE_POINTER_BOUNDS), /* bounds */                       \
>>    DEF_MODE_CLASS (MODE_FRACT),         /* signed fractional number */     \
>>    DEF_MODE_CLASS (MODE_UFRACT),                /* unsigned fractional number */   \
>>    DEF_MODE_CLASS (MODE_ACCUM),         /* signed accumulator */           \
>> diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
>> index 084d195..af0ab88 100644
>> --- a/gcc/stor-layout.c
>> +++ b/gcc/stor-layout.c
>> @@ -386,6 +386,7 @@ int_mode_for_mode (enum machine_mode mode)
>>      case MODE_VECTOR_ACCUM:
>>      case MODE_VECTOR_UFRACT:
>>      case MODE_VECTOR_UACCUM:
>> +    case MODE_POINTER_BOUNDS:
>>        mode = mode_for_size (GET_MODE_BITSIZE (mode), MODE_INT, 0);
>>        break;
>>
>> @@ -2124,6 +2125,11 @@ layout_type (tree type)
>>        SET_TYPE_MODE (type, VOIDmode);
>>        break;
>>
>> +    case POINTER_BOUNDS_TYPE:
>> +      TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type)));
>> +      TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type)));
>> +      break;
>> +
>>      case OFFSET_TYPE:
>>        TYPE_SIZE (type) = bitsize_int (POINTER_SIZE);
>>        TYPE_SIZE_UNIT (type) = size_int (POINTER_SIZE / BITS_PER_UNIT);
>> diff --git a/gcc/tree-pretty-print.c b/gcc/tree-pretty-print.c
>> index 83d5ca6..5fd0f6b 100644
>> --- a/gcc/tree-pretty-print.c
>> +++ b/gcc/tree-pretty-print.c
>> @@ -869,6 +869,7 @@ dump_generic_node (pretty_printer *buffer, tree node, int spc, int flags,
>>        break;
>>
>>      case VOID_TYPE:
>> +    case POINTER_BOUNDS_TYPE:
>>      case INTEGER_TYPE:
>>      case REAL_TYPE:
>>      case FIXED_POINT_TYPE:
>> diff --git a/gcc/tree.c b/gcc/tree.c
>> index efee5e6..6a2ca1c 100644
>> --- a/gcc/tree.c
>> +++ b/gcc/tree.c
>> @@ -1158,7 +1158,8 @@ build_int_cst_wide (tree type, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
>>
>>      case POINTER_TYPE:
>>      case REFERENCE_TYPE:
>> -      /* Cache NULL pointer.  */
>> +    case POINTER_BOUNDS_TYPE:
>> +      /* Cache NULL pointer and zero bounds.  */
>>        if (!hi && !low)
>>         {
>>           limit = 1;
>> @@ -3287,6 +3288,7 @@ type_contains_placeholder_1 (const_tree type)
>>    switch (TREE_CODE (type))
>>      {
>>      case VOID_TYPE:
>> +    case POINTER_BOUNDS_TYPE:
>>      case COMPLEX_TYPE:
>>      case ENUMERAL_TYPE:
>>      case BOOLEAN_TYPE:
>> diff --git a/gcc/tree.def b/gcc/tree.def
>> index f8d6444..42eb758 100644
>> --- a/gcc/tree.def
>> +++ b/gcc/tree.def
>> @@ -232,6 +232,11 @@ DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0)
>>  /* The void type in C */
>>  DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0)
>>
>> +/* Type to hold bounds for a pointer.
>> +   Has TYPE_PRECISION component to specify number of bits used
>> +   by this type.  */
>> +DEFTREECODE (POINTER_BOUNDS_TYPE, "pointer_bounds_type", tcc_type, 0)
>> +
>>  /* Type of functions.  Special fields:
>>     TREE_TYPE               type of value returned.
>>     TYPE_ARG_TYPES      list of types of arguments expected.
>> diff --git a/gcc/tree.h b/gcc/tree.h
>> index 9fbc5c4..f347b9b 100644
>> --- a/gcc/tree.h
>> +++ b/gcc/tree.h
>> @@ -548,6 +548,10 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
>>  /* Nonzero if this type is a complete type.  */
>>  #define COMPLETE_TYPE_P(NODE) (TYPE_SIZE (NODE) != NULL_TREE)
>>
>> +/* Nonzero if this type is a pointer bounds type.  */
>> +#define POINTER_BOUNDS_TYPE_P(NODE) \
>> +  (TREE_CODE (NODE) == POINTER_BOUNDS_TYPE)
>> +
>>  /* Nonzero if this type is the (possibly qualified) void type.  */
>>  #define VOID_TYPE_P(NODE) (TREE_CODE (NODE) == VOID_TYPE)
>>
>> diff --git a/gcc/varasm.c b/gcc/varasm.c
>> index 8e8c5f6..af7fb4a 100644
>> --- a/gcc/varasm.c
>> +++ b/gcc/varasm.c
>> @@ -4700,6 +4700,7 @@ output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
>>      case REFERENCE_TYPE:
>>      case OFFSET_TYPE:
>>      case FIXED_POINT_TYPE:
>> +    case POINTER_BOUNDS_TYPE:
>>      case NULLPTR_TYPE:
>>        if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
>>                                            EXPAND_INITIALIZER),
>
> Will install it in a couple of days.

Please avoid putting in this patch series piece-mail and instead wait until
all parts are approved.

Thanks,
Richard.

> Ilya