Re: [PATCH v9 2/5] Convert references with "counted_by" attributes to/from .ACCESS_WITH_SIZE.
Richard and Joseph:
> On May 28, 2024, at 17:09, Qing Zhao wrote:
>
>>>
>>> diff --git a/gcc/varasm.cc b/gcc/varasm.cc
>>> index fa17eff551e8..d75b23668925 100644
>>> --- a/gcc/varasm.cc
>>> +++ b/gcc/varasm.cc
>>> @@ -5082,6 +5082,11 @@ initializer_constant_valid_p_1 (tree value, tree
>>> endtype, tree *cache)
>>> }
>>> return ret;
>>>
>>> +case CALL_EXPR:
>>> + /* For a call to .ACCESS_WITH_SIZE, check the first argument. */
>>> + if (tree ref = get_ref_from_access_with_size (value))
>>> + return initializer_constant_valid_p_1 (ref, endtype, cache);
>>
>> I think we should fold/strip .ACCESS_WITH_SIZE from initializers
>> instead. That would be
>> the frontends job I guess, most probably not even generate those in
>> the first place?
>
> Sounds reasonable, I will see how to do this in C FE.
> Joseph, do you have any suggestion where in C FE I should do this folding?
>
> thanks.
>
> Qing
In order to address this above comment from Richard, I studied a little bit
more on the C FE code, and then come up with the following patch:
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index ac306749e8d7..efd111305b5a 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -8650,6 +8650,20 @@ digest_init (location_t init_loc, tree type, tree init,
tree origtype,
STRIP_TYPE_NOPS (inside_init);
+ /* If require_constant is TRUE, when the initializer is a call to
+ .ACCESS_WITH_SIZE, use the first argument as the initializer.
+ For example:
+ y = (char *) .ACCESS_WITH_SIZE ((char *) _annotated.c,...)
+ will be converted to
+ y = _annotated.c. */
+
+ if (require_constant
+ && TREE_CODE (inside_init) == NOP_EXPR
+ && TREE_CODE (TREE_OPERAND (inside_init, 0)) == CALL_EXPR
+ && is_access_with_size_p (TREE_OPERAND (inside_init, 0)))
+inside_init
+ = get_ref_from_access_with_size (TREE_OPERAND (inside_init, 0));
+
if (!c_in_omp_for)
{
if (TREE_CODE (inside_init) == EXCESS_PRECISION_EXPR)
diff --git a/gcc/varasm.cc b/gcc/varasm.cc
index 2e8fa5e30a80..e1a8458f8749 100644
--- a/gcc/varasm.cc
+++ b/gcc/varasm.cc
@@ -5078,10 +5078,6 @@ initializer_constant_valid_p_1 (tree value, tree
endtype, tree *cache)
}
return ret;
-case CALL_EXPR:
- /* For a call to .ACCESS_WITH_SIZE, check the first argument. */
- if (tree ref = get_ref_from_access_with_size (value))
- return initializer_constant_valid_p_1 (ref, endtype, cache);
/* FALLTHROUGH. */
default:
break;
@@ -5277,11 +5273,6 @@ output_constant (tree exp, unsigned HOST_WIDE_INT size,
unsigned int align,
exp = TREE_OPERAND (exp, 0);
}
- /* For a call to .ACCESS_WITH_SIZE, check the first argument. */
- if (TREE_CODE (exp) == CALL_EXPR)
-if (tree ref = get_ref_from_access_with_size (exp))
- exp = ref;
-
code = TREE_CODE (TREE_TYPE (exp));
This resolved the issue well.
Let me know if you have any comment or suggestion.
I have fixed all the issues Richard raised in my private workspace, testing is
ongoing.
Will post the modified patch set soon.
Thanks a lot!
Qing
Re: [PATCH v9 2/5] Convert references with "counted_by" attributes to/from .ACCESS_WITH_SIZE.
> On May 29, 2024, at 02:57, Richard Biener wrote: > > On Tue, May 28, 2024 at 11:09 PM Qing Zhao wrote: >> >> Thank you for the comments. See my answers below: >> >> Joseph, please see the last question, I need your help on it. Thanks a lot >> for the help. >> >> Qing >> >>> On May 28, 2024, at 03:38, Richard Biener >>> wrote: >>> >>> On Fri, Apr 12, 2024 at 3:54 PM Qing Zhao wrote: Including the following changes: * The definition of the new internal function .ACCESS_WITH_SIZE in internal-fn.def. * C FE converts every reference to a FAM with a "counted_by" attribute to a call to the internal function .ACCESS_WITH_SIZE. (build_component_ref in c_typeck.cc) This includes the case when the object is statically allocated and initialized. In order to make this working, the routines initializer_constant_valid_p_1 and output_constant in varasm.cc are updated to handle calls to .ACCESS_WITH_SIZE. (initializer_constant_valid_p_1 and output_constant in varasm.c) However, for the reference inside "offsetof", the "counted_by" attribute is ignored since it's not useful at all. (c_parser_postfix_expression in c/c-parser.cc) In addtion to "offsetof", for the reference inside operator "typeof" and "alignof", we ignore counted_by attribute too. When building ADDR_EXPR for the .ACCESS_WITH_SIZE in C FE, replace the call with its first argument. * Convert every call to .ACCESS_WITH_SIZE to its first argument. (expand_ACCESS_WITH_SIZE in internal-fn.cc) * Adjust alias analysis to exclude the new internal from clobbering anything. (ref_maybe_used_by_call_p_1 and call_may_clobber_ref_p_1 in tree-ssa-alias.cc) * Adjust dead code elimination to eliminate the call to .ACCESS_WITH_SIZE when it's LHS is eliminated as dead code. (eliminate_unnecessary_stmts in tree-ssa-dce.cc) * Provide the utility routines to check the call is .ACCESS_WITH_SIZE and get the reference from the call to .ACCESS_WITH_SIZE. (is_access_with_size_p and get_ref_from_access_with_size in tree.cc) gcc/c/ChangeLog: * c-parser.cc (c_parser_postfix_expression): Ignore the counted-by attribute when build_component_ref inside offsetof operator. * c-tree.h (build_component_ref): Add one more parameter. * c-typeck.cc (build_counted_by_ref): New function. (build_access_with_size_for_counted_by): New function. (build_component_ref): Check the counted-by attribute and build call to .ACCESS_WITH_SIZE. (build_unary_op): When building ADDR_EXPR for .ACCESS_WITH_SIZE, use its first argument. (lvalue_p): Accept call to .ACCESS_WITH_SIZE. gcc/ChangeLog: * internal-fn.cc (expand_ACCESS_WITH_SIZE): New function. * internal-fn.def (ACCESS_WITH_SIZE): New internal function. * tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): Special case IFN_ACCESS_WITH_SIZE. (call_may_clobber_ref_p_1): Special case IFN_ACCESS_WITH_SIZE. * tree-ssa-dce.cc (eliminate_unnecessary_stmts): Eliminate the call to .ACCESS_WITH_SIZE when its LHS is dead. * tree.cc (process_call_operands): Adjust side effect for function .ACCESS_WITH_SIZE. (is_access_with_size_p): New function. (get_ref_from_access_with_size): New function. * tree.h (is_access_with_size_p): New prototype. (get_ref_from_access_with_size): New prototype. * varasm.cc (initializer_constant_valid_p_1): Handle call to .ACCESS_WITH_SIZE. (output_constant): Handle call to .ACCESS_WITH_SIZE. gcc/testsuite/ChangeLog: * gcc.dg/flex-array-counted-by-2.c: New test. --- gcc/c/c-parser.cc | 10 +- gcc/c/c-tree.h| 2 +- gcc/c/c-typeck.cc | 128 +- gcc/internal-fn.cc| 35 + gcc/internal-fn.def | 4 + .../gcc.dg/flex-array-counted-by-2.c | 112 +++ gcc/tree-ssa-alias.cc | 2 + gcc/tree-ssa-dce.cc | 5 +- gcc/tree.cc | 25 +++- gcc/tree.h| 8 ++ gcc/varasm.cc | 10 ++ 11 files changed, 331 insertions(+), 10 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/flex-array-counted-by-2.c diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc index c31349dae2ff..a6ed5ac43bb1 100644 --- a/gcc/c/c-parser.cc +++ b/gcc/c/c-parser.cc @@ -10850,9 +10850,12 @@ c_parser_postfix_expression
Re: [PATCH v9 2/5] Convert references with "counted_by" attributes to/from .ACCESS_WITH_SIZE.
On Tue, May 28, 2024 at 11:09 PM Qing Zhao wrote: > > Thank you for the comments. See my answers below: > > Joseph, please see the last question, I need your help on it. Thanks a lot > for the help. > > Qing > > > On May 28, 2024, at 03:38, Richard Biener > > wrote: > > > > On Fri, Apr 12, 2024 at 3:54 PM Qing Zhao wrote: > >> > >> Including the following changes: > >> * The definition of the new internal function .ACCESS_WITH_SIZE > >> in internal-fn.def. > >> * C FE converts every reference to a FAM with a "counted_by" attribute > >> to a call to the internal function .ACCESS_WITH_SIZE. > >> (build_component_ref in c_typeck.cc) > >> > >> This includes the case when the object is statically allocated and > >> initialized. > >> In order to make this working, the routines initializer_constant_valid_p_1 > >> and output_constant in varasm.cc are updated to handle calls to > >> .ACCESS_WITH_SIZE. > >> (initializer_constant_valid_p_1 and output_constant in varasm.c) > >> > >> However, for the reference inside "offsetof", the "counted_by" attribute > >> is > >> ignored since it's not useful at all. > >> (c_parser_postfix_expression in c/c-parser.cc) > >> > >> In addtion to "offsetof", for the reference inside operator "typeof" and > >> "alignof", we ignore counted_by attribute too. > >> > >> When building ADDR_EXPR for the .ACCESS_WITH_SIZE in C FE, > >> replace the call with its first argument. > >> > >> * Convert every call to .ACCESS_WITH_SIZE to its first argument. > >> (expand_ACCESS_WITH_SIZE in internal-fn.cc) > >> * Adjust alias analysis to exclude the new internal from clobbering > >> anything. > >> (ref_maybe_used_by_call_p_1 and call_may_clobber_ref_p_1 in > >> tree-ssa-alias.cc) > >> * Adjust dead code elimination to eliminate the call to .ACCESS_WITH_SIZE > >> when > >> it's LHS is eliminated as dead code. > >> (eliminate_unnecessary_stmts in tree-ssa-dce.cc) > >> * Provide the utility routines to check the call is .ACCESS_WITH_SIZE and > >> get the reference from the call to .ACCESS_WITH_SIZE. > >> (is_access_with_size_p and get_ref_from_access_with_size in tree.cc) > >> > >> gcc/c/ChangeLog: > >> > >>* c-parser.cc (c_parser_postfix_expression): Ignore the counted-by > >>attribute when build_component_ref inside offsetof operator. > >>* c-tree.h (build_component_ref): Add one more parameter. > >>* c-typeck.cc (build_counted_by_ref): New function. > >>(build_access_with_size_for_counted_by): New function. > >>(build_component_ref): Check the counted-by attribute and build > >>call to .ACCESS_WITH_SIZE. > >>(build_unary_op): When building ADDR_EXPR for > >>.ACCESS_WITH_SIZE, use its first argument. > >>(lvalue_p): Accept call to .ACCESS_WITH_SIZE. > >> > >> gcc/ChangeLog: > >> > >>* internal-fn.cc (expand_ACCESS_WITH_SIZE): New function. > >>* internal-fn.def (ACCESS_WITH_SIZE): New internal function. > >>* tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): Special case > >>IFN_ACCESS_WITH_SIZE. > >>(call_may_clobber_ref_p_1): Special case IFN_ACCESS_WITH_SIZE. > >>* tree-ssa-dce.cc (eliminate_unnecessary_stmts): Eliminate the call > >>to .ACCESS_WITH_SIZE when its LHS is dead. > >>* tree.cc (process_call_operands): Adjust side effect for function > >>.ACCESS_WITH_SIZE. > >>(is_access_with_size_p): New function. > >>(get_ref_from_access_with_size): New function. > >>* tree.h (is_access_with_size_p): New prototype. > >>(get_ref_from_access_with_size): New prototype. > >>* varasm.cc (initializer_constant_valid_p_1): Handle call to > >>.ACCESS_WITH_SIZE. > >>(output_constant): Handle call to .ACCESS_WITH_SIZE. > >> > >> gcc/testsuite/ChangeLog: > >> > >>* gcc.dg/flex-array-counted-by-2.c: New test. > >> --- > >> gcc/c/c-parser.cc | 10 +- > >> gcc/c/c-tree.h| 2 +- > >> gcc/c/c-typeck.cc | 128 +- > >> gcc/internal-fn.cc| 35 + > >> gcc/internal-fn.def | 4 + > >> .../gcc.dg/flex-array-counted-by-2.c | 112 +++ > >> gcc/tree-ssa-alias.cc | 2 + > >> gcc/tree-ssa-dce.cc | 5 +- > >> gcc/tree.cc | 25 +++- > >> gcc/tree.h| 8 ++ > >> gcc/varasm.cc | 10 ++ > >> 11 files changed, 331 insertions(+), 10 deletions(-) > >> create mode 100644 gcc/testsuite/gcc.dg/flex-array-counted-by-2.c > >> > >> diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc > >> index c31349dae2ff..a6ed5ac43bb1 100644 > >> --- a/gcc/c/c-parser.cc > >> +++ b/gcc/c/c-parser.cc > >> @@ -10850,9 +10850,12 @@ c_parser_postfix_expression (c_parser *parser) > >>
Re: [PATCH v9 2/5] Convert references with "counted_by" attributes to/from .ACCESS_WITH_SIZE.
Thank you for the comments. See my answers below:
Joseph, please see the last question, I need your help on it. Thanks a lot for
the help.
Qing
> On May 28, 2024, at 03:38, Richard Biener wrote:
>
> On Fri, Apr 12, 2024 at 3:54 PM Qing Zhao wrote:
>>
>> Including the following changes:
>> * The definition of the new internal function .ACCESS_WITH_SIZE
>> in internal-fn.def.
>> * C FE converts every reference to a FAM with a "counted_by" attribute
>> to a call to the internal function .ACCESS_WITH_SIZE.
>> (build_component_ref in c_typeck.cc)
>>
>> This includes the case when the object is statically allocated and
>> initialized.
>> In order to make this working, the routines initializer_constant_valid_p_1
>> and output_constant in varasm.cc are updated to handle calls to
>> .ACCESS_WITH_SIZE.
>> (initializer_constant_valid_p_1 and output_constant in varasm.c)
>>
>> However, for the reference inside "offsetof", the "counted_by" attribute is
>> ignored since it's not useful at all.
>> (c_parser_postfix_expression in c/c-parser.cc)
>>
>> In addtion to "offsetof", for the reference inside operator "typeof" and
>> "alignof", we ignore counted_by attribute too.
>>
>> When building ADDR_EXPR for the .ACCESS_WITH_SIZE in C FE,
>> replace the call with its first argument.
>>
>> * Convert every call to .ACCESS_WITH_SIZE to its first argument.
>> (expand_ACCESS_WITH_SIZE in internal-fn.cc)
>> * Adjust alias analysis to exclude the new internal from clobbering anything.
>> (ref_maybe_used_by_call_p_1 and call_may_clobber_ref_p_1 in
>> tree-ssa-alias.cc)
>> * Adjust dead code elimination to eliminate the call to .ACCESS_WITH_SIZE
>> when
>> it's LHS is eliminated as dead code.
>> (eliminate_unnecessary_stmts in tree-ssa-dce.cc)
>> * Provide the utility routines to check the call is .ACCESS_WITH_SIZE and
>> get the reference from the call to .ACCESS_WITH_SIZE.
>> (is_access_with_size_p and get_ref_from_access_with_size in tree.cc)
>>
>> gcc/c/ChangeLog:
>>
>>* c-parser.cc (c_parser_postfix_expression): Ignore the counted-by
>>attribute when build_component_ref inside offsetof operator.
>>* c-tree.h (build_component_ref): Add one more parameter.
>>* c-typeck.cc (build_counted_by_ref): New function.
>>(build_access_with_size_for_counted_by): New function.
>>(build_component_ref): Check the counted-by attribute and build
>>call to .ACCESS_WITH_SIZE.
>>(build_unary_op): When building ADDR_EXPR for
>>.ACCESS_WITH_SIZE, use its first argument.
>>(lvalue_p): Accept call to .ACCESS_WITH_SIZE.
>>
>> gcc/ChangeLog:
>>
>>* internal-fn.cc (expand_ACCESS_WITH_SIZE): New function.
>>* internal-fn.def (ACCESS_WITH_SIZE): New internal function.
>>* tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): Special case
>>IFN_ACCESS_WITH_SIZE.
>>(call_may_clobber_ref_p_1): Special case IFN_ACCESS_WITH_SIZE.
>>* tree-ssa-dce.cc (eliminate_unnecessary_stmts): Eliminate the call
>>to .ACCESS_WITH_SIZE when its LHS is dead.
>>* tree.cc (process_call_operands): Adjust side effect for function
>>.ACCESS_WITH_SIZE.
>>(is_access_with_size_p): New function.
>>(get_ref_from_access_with_size): New function.
>>* tree.h (is_access_with_size_p): New prototype.
>>(get_ref_from_access_with_size): New prototype.
>>* varasm.cc (initializer_constant_valid_p_1): Handle call to
>>.ACCESS_WITH_SIZE.
>>(output_constant): Handle call to .ACCESS_WITH_SIZE.
>>
>> gcc/testsuite/ChangeLog:
>>
>>* gcc.dg/flex-array-counted-by-2.c: New test.
>> ---
>> gcc/c/c-parser.cc | 10 +-
>> gcc/c/c-tree.h| 2 +-
>> gcc/c/c-typeck.cc | 128 +-
>> gcc/internal-fn.cc| 35 +
>> gcc/internal-fn.def | 4 +
>> .../gcc.dg/flex-array-counted-by-2.c | 112 +++
>> gcc/tree-ssa-alias.cc | 2 +
>> gcc/tree-ssa-dce.cc | 5 +-
>> gcc/tree.cc | 25 +++-
>> gcc/tree.h| 8 ++
>> gcc/varasm.cc | 10 ++
>> 11 files changed, 331 insertions(+), 10 deletions(-)
>> create mode 100644 gcc/testsuite/gcc.dg/flex-array-counted-by-2.c
>>
>> diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
>> index c31349dae2ff..a6ed5ac43bb1 100644
>> --- a/gcc/c/c-parser.cc
>> +++ b/gcc/c/c-parser.cc
>> @@ -10850,9 +10850,12 @@ c_parser_postfix_expression (c_parser *parser)
>>if (c_parser_next_token_is (parser, CPP_NAME))
>> {
>>c_token *comp_tok = c_parser_peek_token (parser);
>> + /* Ignore the counted_by attribute for reference inside
>> + offsetof since the
Re: [PATCH v9 2/5] Convert references with "counted_by" attributes to/from .ACCESS_WITH_SIZE.
On Fri, Apr 12, 2024 at 3:54 PM Qing Zhao wrote:
>
> Including the following changes:
> * The definition of the new internal function .ACCESS_WITH_SIZE
> in internal-fn.def.
> * C FE converts every reference to a FAM with a "counted_by" attribute
> to a call to the internal function .ACCESS_WITH_SIZE.
> (build_component_ref in c_typeck.cc)
>
> This includes the case when the object is statically allocated and
> initialized.
> In order to make this working, the routines initializer_constant_valid_p_1
> and output_constant in varasm.cc are updated to handle calls to
> .ACCESS_WITH_SIZE.
> (initializer_constant_valid_p_1 and output_constant in varasm.c)
>
> However, for the reference inside "offsetof", the "counted_by" attribute is
> ignored since it's not useful at all.
> (c_parser_postfix_expression in c/c-parser.cc)
>
> In addtion to "offsetof", for the reference inside operator "typeof" and
> "alignof", we ignore counted_by attribute too.
>
> When building ADDR_EXPR for the .ACCESS_WITH_SIZE in C FE,
> replace the call with its first argument.
>
> * Convert every call to .ACCESS_WITH_SIZE to its first argument.
> (expand_ACCESS_WITH_SIZE in internal-fn.cc)
> * Adjust alias analysis to exclude the new internal from clobbering anything.
> (ref_maybe_used_by_call_p_1 and call_may_clobber_ref_p_1 in
> tree-ssa-alias.cc)
> * Adjust dead code elimination to eliminate the call to .ACCESS_WITH_SIZE when
> it's LHS is eliminated as dead code.
> (eliminate_unnecessary_stmts in tree-ssa-dce.cc)
> * Provide the utility routines to check the call is .ACCESS_WITH_SIZE and
> get the reference from the call to .ACCESS_WITH_SIZE.
> (is_access_with_size_p and get_ref_from_access_with_size in tree.cc)
>
> gcc/c/ChangeLog:
>
> * c-parser.cc (c_parser_postfix_expression): Ignore the counted-by
> attribute when build_component_ref inside offsetof operator.
> * c-tree.h (build_component_ref): Add one more parameter.
> * c-typeck.cc (build_counted_by_ref): New function.
> (build_access_with_size_for_counted_by): New function.
> (build_component_ref): Check the counted-by attribute and build
> call to .ACCESS_WITH_SIZE.
> (build_unary_op): When building ADDR_EXPR for
> .ACCESS_WITH_SIZE, use its first argument.
> (lvalue_p): Accept call to .ACCESS_WITH_SIZE.
>
> gcc/ChangeLog:
>
> * internal-fn.cc (expand_ACCESS_WITH_SIZE): New function.
> * internal-fn.def (ACCESS_WITH_SIZE): New internal function.
> * tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): Special case
> IFN_ACCESS_WITH_SIZE.
> (call_may_clobber_ref_p_1): Special case IFN_ACCESS_WITH_SIZE.
> * tree-ssa-dce.cc (eliminate_unnecessary_stmts): Eliminate the call
> to .ACCESS_WITH_SIZE when its LHS is dead.
> * tree.cc (process_call_operands): Adjust side effect for function
> .ACCESS_WITH_SIZE.
> (is_access_with_size_p): New function.
> (get_ref_from_access_with_size): New function.
> * tree.h (is_access_with_size_p): New prototype.
> (get_ref_from_access_with_size): New prototype.
> * varasm.cc (initializer_constant_valid_p_1): Handle call to
> .ACCESS_WITH_SIZE.
> (output_constant): Handle call to .ACCESS_WITH_SIZE.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/flex-array-counted-by-2.c: New test.
> ---
> gcc/c/c-parser.cc | 10 +-
> gcc/c/c-tree.h| 2 +-
> gcc/c/c-typeck.cc | 128 +-
> gcc/internal-fn.cc| 35 +
> gcc/internal-fn.def | 4 +
> .../gcc.dg/flex-array-counted-by-2.c | 112 +++
> gcc/tree-ssa-alias.cc | 2 +
> gcc/tree-ssa-dce.cc | 5 +-
> gcc/tree.cc | 25 +++-
> gcc/tree.h| 8 ++
> gcc/varasm.cc | 10 ++
> 11 files changed, 331 insertions(+), 10 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/flex-array-counted-by-2.c
>
> diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
> index c31349dae2ff..a6ed5ac43bb1 100644
> --- a/gcc/c/c-parser.cc
> +++ b/gcc/c/c-parser.cc
> @@ -10850,9 +10850,12 @@ c_parser_postfix_expression (c_parser *parser)
> if (c_parser_next_token_is (parser, CPP_NAME))
> {
> c_token *comp_tok = c_parser_peek_token (parser);
> + /* Ignore the counted_by attribute for reference inside
> + offsetof since the information is not useful at all. */
> offsetof_ref
> = build_component_ref (loc, offsetof_ref, comp_tok->value,
> -comp_tok->location,
> UNKNOWN_LOCATION);
> +
[PATCH v9 2/5] Convert references with "counted_by" attributes to/from .ACCESS_WITH_SIZE.
Including the following changes:
* The definition of the new internal function .ACCESS_WITH_SIZE
in internal-fn.def.
* C FE converts every reference to a FAM with a "counted_by" attribute
to a call to the internal function .ACCESS_WITH_SIZE.
(build_component_ref in c_typeck.cc)
This includes the case when the object is statically allocated and
initialized.
In order to make this working, the routines initializer_constant_valid_p_1
and output_constant in varasm.cc are updated to handle calls to
.ACCESS_WITH_SIZE.
(initializer_constant_valid_p_1 and output_constant in varasm.c)
However, for the reference inside "offsetof", the "counted_by" attribute is
ignored since it's not useful at all.
(c_parser_postfix_expression in c/c-parser.cc)
In addtion to "offsetof", for the reference inside operator "typeof" and
"alignof", we ignore counted_by attribute too.
When building ADDR_EXPR for the .ACCESS_WITH_SIZE in C FE,
replace the call with its first argument.
* Convert every call to .ACCESS_WITH_SIZE to its first argument.
(expand_ACCESS_WITH_SIZE in internal-fn.cc)
* Adjust alias analysis to exclude the new internal from clobbering anything.
(ref_maybe_used_by_call_p_1 and call_may_clobber_ref_p_1 in tree-ssa-alias.cc)
* Adjust dead code elimination to eliminate the call to .ACCESS_WITH_SIZE when
it's LHS is eliminated as dead code.
(eliminate_unnecessary_stmts in tree-ssa-dce.cc)
* Provide the utility routines to check the call is .ACCESS_WITH_SIZE and
get the reference from the call to .ACCESS_WITH_SIZE.
(is_access_with_size_p and get_ref_from_access_with_size in tree.cc)
gcc/c/ChangeLog:
* c-parser.cc (c_parser_postfix_expression): Ignore the counted-by
attribute when build_component_ref inside offsetof operator.
* c-tree.h (build_component_ref): Add one more parameter.
* c-typeck.cc (build_counted_by_ref): New function.
(build_access_with_size_for_counted_by): New function.
(build_component_ref): Check the counted-by attribute and build
call to .ACCESS_WITH_SIZE.
(build_unary_op): When building ADDR_EXPR for
.ACCESS_WITH_SIZE, use its first argument.
(lvalue_p): Accept call to .ACCESS_WITH_SIZE.
gcc/ChangeLog:
* internal-fn.cc (expand_ACCESS_WITH_SIZE): New function.
* internal-fn.def (ACCESS_WITH_SIZE): New internal function.
* tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): Special case
IFN_ACCESS_WITH_SIZE.
(call_may_clobber_ref_p_1): Special case IFN_ACCESS_WITH_SIZE.
* tree-ssa-dce.cc (eliminate_unnecessary_stmts): Eliminate the call
to .ACCESS_WITH_SIZE when its LHS is dead.
* tree.cc (process_call_operands): Adjust side effect for function
.ACCESS_WITH_SIZE.
(is_access_with_size_p): New function.
(get_ref_from_access_with_size): New function.
* tree.h (is_access_with_size_p): New prototype.
(get_ref_from_access_with_size): New prototype.
* varasm.cc (initializer_constant_valid_p_1): Handle call to
.ACCESS_WITH_SIZE.
(output_constant): Handle call to .ACCESS_WITH_SIZE.
gcc/testsuite/ChangeLog:
* gcc.dg/flex-array-counted-by-2.c: New test.
---
gcc/c/c-parser.cc | 10 +-
gcc/c/c-tree.h| 2 +-
gcc/c/c-typeck.cc | 128 +-
gcc/internal-fn.cc| 35 +
gcc/internal-fn.def | 4 +
.../gcc.dg/flex-array-counted-by-2.c | 112 +++
gcc/tree-ssa-alias.cc | 2 +
gcc/tree-ssa-dce.cc | 5 +-
gcc/tree.cc | 25 +++-
gcc/tree.h| 8 ++
gcc/varasm.cc | 10 ++
11 files changed, 331 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/flex-array-counted-by-2.c
diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index c31349dae2ff..a6ed5ac43bb1 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -10850,9 +10850,12 @@ c_parser_postfix_expression (c_parser *parser)
if (c_parser_next_token_is (parser, CPP_NAME))
{
c_token *comp_tok = c_parser_peek_token (parser);
+ /* Ignore the counted_by attribute for reference inside
+ offsetof since the information is not useful at all. */
offsetof_ref
= build_component_ref (loc, offsetof_ref, comp_tok->value,
-comp_tok->location, UNKNOWN_LOCATION);
+comp_tok->location, UNKNOWN_LOCATION,
+false);
c_parser_consume_token (parser);
while (c_parser_next_token_is (parser, CPP_DOT)
||
