On Fri, Jun 13, 2014 at 1:38 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
> 2014-06-12 11:55 GMT+04:00 Richard Biener <richard.guent...@gmail.com>:
>> On Wed, Jun 11, 2014 at 6:08 PM, Ilya Enkovich <enkovich....@gmail.com>
>> wrote:
>>> Hi,
>>>
>>> This patch fixes problem with size emitted for static structures with
>>> flexible array. I found a couple of trackers in guzilla for this problem
>>> but all of them are marked as fixed and problem still exists.
>>>
>>> For a simple testcase
>>>
>>> struct S { int a; int b[0]; } s = { 1, { 0, 0} };
>>>
>>> current trunk produces (no flags):
>>>
>>> .globl s
>>> .data
>>> .align 4
>>> .type s, @object
>>> .size s, 4
>>> s:
>>> .long 1
>>> .long 0
>>> .long 0
>>>
>>> which has wrong size for object s.
>>>
>>> This problem is important for checker because wrong size leads to wrong
>>> bounds and false bounds violations. Following patch uses DECL_SIZE_UNIT
>>> instead of type size and works well for me. Does it look OK?
>>
>> There is a bug about this in bugzilla somewhere.
>
> I looked through bugzilla and found two trackers with similar problem.
>
> The first one is 57180 which is still open but with comment that
> problem is fixed on the trunk. I checked it and it really passes for
> the trunk (should tracker be closed then?).
>
> Another one is 28865 (and a set of its duplicates). Interesting thing
> here is that original testcase uses array of integers but testcases
> which were added with commit use arrays of chars. Original test is
> still compiled wrongly. I also see that a patch very similar to what I
> posted was proposed as a solution but it was reported to cause a
> problem with glibc/nss/nss_files/files-init.c. There is a
> corresponding testcase in the tracker which results wrong padding when
> patch is applied but it seems to be another problem because I do not
> see any problem when use mpx compiler branch for this testcase.
>
>>
>> It looks ok to me - did you test with all languages? In particular did
>> you test Ada?
>
> I configure compiler with no language disabling and then run bootstrap
> and make check. Does it mean all languages are covered? Will make more
> testing if required.
That only enables default languages which excludes Objective-C++, Ada
and Go. To enable really all languages you have to specify
--enable-languages=all,ada,obj-c++,go
Richard.
> Thanks,
> Ilya
>
>>
>> Thanks,
>> Richard.
>>
>>> Bootstrapped and tested on linux-x86_64.
>>>
>>> Thanks,
>>> Ilya
>>> --
>>> gcc/
>>>
>>> 2014-06-11 Ilya Enkovich <ilya.enkov...@intel.com>
>>>
>>> * config/elfos.h (ASM_DECLARE_OBJECT_NAME): Use decl size
>>> instead of type size.
>>> (ASM_FINISH_DECLARE_OBJECT): Likewise.
>>>
>>>
>>> diff --git a/gcc/config/elfos.h b/gcc/config/elfos.h
>>> index c1d5553..7929708 100644
>>> --- a/gcc/config/elfos.h
>>> +++ b/gcc/config/elfos.h
>>> @@ -313,7 +313,7 @@ see the files COPYING3 and COPYING.RUNTIME
>>> respectively. If not, see
>>> && (DECL) && DECL_SIZE (DECL)) \
>>> { \
>>> size_directive_output = 1; \
>>> - size = int_size_in_bytes (TREE_TYPE (DECL)); \
>>> + size = tree_to_uhwi (DECL_SIZE_UNIT (DECL)); \
>>> ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size); \
>>> } \
>>> \
>>> @@ -341,7 +341,7 @@ see the files COPYING3 and COPYING.RUNTIME
>>> respectively. If not, see
>>> && !size_directive_output) \
>>> { \
>>> size_directive_output = 1; \
>>> - size = int_size_in_bytes (TREE_TYPE (DECL)); \
>>> + size = tree_to_uhwi (DECL_SIZE_UNIT (DECL)); \
>>> ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size); \
>>> } \
>>> } \
