On 11/16/21 01:55, Jeff Law wrote:
On 11/15/2021 10:33 AM, Siddhesh Poyarekar wrote:
Instead of comparing LEN and SIZE only if they are constants, use their
ranges to decide if LEN will always be lower than or same as SIZE.
This change ends up putting the stringop-overflow warning line number
against the strcpy implementation, so adjust the warning check to be
line number agnostic.
gcc/ChangeLog:
* gimple-fold.c (known_lower): New function.
(gimple_fold_builtin_strncat_chk,
gimple_fold_builtin_memory_chk, gimple_fold_builtin_stxcpy_chk,
gimple_fold_builtin_stxncpy_chk,
gimple_fold_builtin_snprintf_chk,
gimple_fold_builtin_sprintf_chk): Use it.
gcc/testsuite/ChangeLog:
* gcc.dg/Wobjsize-1.c: Make warning change line agnostic.
* gcc.dg/builtin-chk-fold.c: New test.
@@ -3024,39 +3040,24 @@ gimple_fold_builtin_memory_chk
(gimple_stmt_iterator *gsi,
}
}
- if (! tree_fits_uhwi_p (size))
- return false;
-
tree maxlen = get_maxval_strlen (len, SRK_INT_VALUE);
- if (! integer_all_onesp (size))
+ if (! integer_all_onesp (size)
+ && !known_lower (stmt, len, size) && !known_lower (stmt,
maxlen, size))
Formatting it. Move the trailing && !known_lower (...) to its own line.
OK with the formatting nit fixed.
Thanks, I fixed the nit and pushed the series.
Siddhesh
