On 05/11/2018 05:09 PM, Martin Sebor wrote:
> The attached patch extends -Wrestrict to constrain valid offset
> ranges into objects of struct types to the bounds of the object
> type, the same way the warning already handles arrays. This
> makes it possible to detect overlapping accesses in cases like
> the second call to memcpy below:
>
> char a[16];
>
> struct { char a[16]; } x;
>
> void f (int i, int j)
> {
> memcpy (&a[i], &a[j], 9); // -Wrestrict (good)
>
> memcpy (&x.a[i], &x.a[j], 9); // missing -Wrestrict
> }
>
> These is no way to copy 9 bytes within a 16 byte array without
> either overlap or without accessing memory outside the bounaries
> of the object.
>
> This is for GCC 9.
>
> Thanks
> Martin
>
> gcc-85753.diff
>
>
> PR tree-optimization/85753 - missing -Wrestrict on memcpy into a member array
>
> gcc/ChangeLog:
>
> PR tree-optimization/85753
> * gimple-ssa-warn-restrict.c (builtin_memref::builtin_memref): Handle
> RECORD_TYPE in addition to ARRAY_TYPE.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/85753
> * gcc.dg/Wrestrict-10.c: Adjust.
> * gcc.dg/Wrestrict-16.c: New test.
OK.
jeff
