[Bug middle-end/89428] missing -Wstringop-overflow on a PHI with variable offset
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89428 Martin Sebor changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED Target Milestone|--- |11.0 --- Comment #6 from Martin Sebor --- Resolved by r11-5523 for GCC 11 which now issues the following warnings for the test case in comment #0 (the duplicate note needs to be fixed): $ gcc -O2 -S pr89428.c pr89428.c: In function ‘f’: pr89428.c:7:3: warning: ‘__builtin_memset’ writing 7 bytes into a region of size 6 overflows the destination [-Wstringop-overflow=] 7 | __builtin_memset (a + i, 0, 7); // warning (good) | ^~ pr89428.c:1:6: note: at offset [1, 2] into destination object ‘a’ of size 7 1 | char a[7]; | ^ pr89428.c: In function ‘g’: pr89428.c:14:3: warning: ‘__builtin_memset’ writing 99 bytes into a region of size 7 overflows the destination [-Wstringop-overflow=] 14 | __builtin_memset (a + i, 0, 99); // missing warning (bug) | ^~~ pr89428.c:1:6: note: destination object ‘a’ of size 7 1 | char a[7]; | ^ pr89428.c:1:6: note: destination object ‘a’ of size 7
[Bug middle-end/89428] missing -Wstringop-overflow on a PHI with variable offset
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89428
--- Comment #5 from CVS Commits ---
The master branch has been updated by Martin Sebor :
https://gcc.gnu.org/g:eafe8ee7af13c39805ea09bbf5b4f9ab2a48304a
commit r11-5523-geafe8ee7af13c39805ea09bbf5b4f9ab2a48304a
Author: Martin Sebor
Date: Sun Nov 29 15:09:30 2020 -0700
Handle PHIs in compute_objsize.
PR middle-end/92936 - missing warning on a past-the-end store to a PHI
PR middle-end/92940 - incorrect offset and size in -Wstringop-overflow for
out-of-bounds store into VLA and two offset ranges
PR middle-end/89428 - missing -Wstringop-overflow on a PHI with variable
offset
gcc/ChangeLog:
PR middle-end/92936
PR middle-end/92940
PR middle-end/89428
* builtins.c (access_ref::access_ref): Initialize member.
(access_ref::phi): New function.
(access_ref::get_ref): New function.
(access_ref::add_offset): Remove duplicate assignment.
(maybe_warn_for_bound): Add "maybe" kind of warning messages.
(warn_for_access): Same.
(inform_access): Rename...
(access_ref::inform_access): ...to this. Print PHI arguments.
Format
offset the same as size and simplify. Improve printing of
allocation
functions and VLAs.
(check_access): Adjust to the above.
(gimple_parm_array_size): Change argument.
(handle_min_max_size): New function.
* builtins.h (class ssa_name_limit_t): Move class here from
tree-ssa-strlen.c.
(struct access_ref): Declare new members.
(gimple_parm_array_size): Change argument.
* tree-ssa-strlen.c (maybe_warn_overflow): Use access_ref and
simplify.
(handle_builtin_memcpy): Correct argument passed to
maybe_warn_overflow.
(handle_builtin_memset): Same.
(class ssa_name_limit_t): Move class to builtins.{h,c}.
gcc/testsuite/ChangeLog:
PR middle-end/92936
PR middle-end/92940
PR middle-end/89428
* c-c++-common/Wstringop-overflow-2.c: Adjust text of expected
informational notes.
* g++.dg/warn/Wstringop-overflow-3.C: Same.
* g++.dg/warn/Wplacement-new-size.C: Remove a test for a no longer
issued warning.
* gcc.dg/Warray-bounds-43.c: Removed unused declarations.
* gcc.dg/Wstringop-overflow-11.c: Remove xfails.
* gcc.dg/Wstringop-overflow-12.c: Same.
* gcc.dg/Wstringop-overflow-17.c: Adjust text of expected messages.
* gcc.dg/Wstringop-overflow-27.c: Same. Remove xfails.
* gcc.dg/Wstringop-overflow-28.c: Adjust text of expected messages.
* gcc.dg/Wstringop-overflow-29.c: Same.
* gcc.dg/Wstringop-overflow-37.c: Same.
* gcc.dg/Wstringop-overflow-46.c: Same.
* gcc.dg/Wstringop-overflow-47.c: Same.
* gcc.dg/Wstringop-overflow-54.c: Same.
* gcc.dg/warn-strnlen-no-nul.c: Add expected warning.
* gcc.dg/Wstringop-overflow-7.c: New test.
* gcc.dg/Wstringop-overflow-58.c: New test.
* gcc.dg/Wstringop-overflow-59.c: New test.
* gcc.dg/Wstringop-overflow-60.c: New test.
* gcc.dg/Wstringop-overflow-61.c: New test.
* gcc.dg/Wstringop-overflow-62.c: New test.
* gcc.dg/Wstringop-overflow-63.c: New test.
* gcc.dg/Wstringop-overflow-64.c: New test.
[Bug middle-end/89428] missing -Wstringop-overflow on a PHI with variable offset
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89428 Martin Sebor changed: What|Removed |Added Keywords||patch Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |msebor at gcc dot gnu.org --- Comment #4 from Martin Sebor --- Fixed in the following patch for pr92936: https://gcc.gnu.org/pipermail/gcc-patches/2020-November/557807.html
[Bug middle-end/89428] missing -Wstringop-overflow on a PHI with variable offset
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89428 Martin Sebor changed: What|Removed |Added See Also||https://gcc.gnu.org/bugzill ||a/show_bug.cgi?id=92936 --- Comment #3 from Martin Sebor --- See also pr92936.
[Bug middle-end/89428] missing -Wstringop-overflow on a PHI with variable offset
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89428 Nicholas Krause changed: What|Removed |Added CC||xerofoify at gmail dot com --- Comment #2 from Nicholas Krause --- Changing i equal to 1 in the second function gives the warning and gets similar GIMPLE like this to the first function: [local count: 1073741824]: i_3 = MAX_EXPR ; _1 = &a + i_3; __builtin_memset (_1, 0, 99); [tail call] return; Are we assuming somewhere that zero size offsets should for the first argument of __builtin_memset to be forgotten about? Because I tried it with multiple numbers other than zero and they all worked to get GIMPLE similar to the above.
[Bug middle-end/89428] missing -Wstringop-overflow on a PHI with variable offset
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89428 Martin Sebor changed: What|Removed |Added Known to fail||10.0, 9.2.0 Last reconfirmed||2020-04-22 Ever confirmed|0 |1 Status|UNCONFIRMED |NEW --- Comment #1 from Martin Sebor --- No progress in GCC 10.
