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From: "aldyh at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/107561] [13 Regression] g++.dg/pr17488.C and [g++.dg/warn/Warray-bounds-16.C -m32] regression due to -Wstringop-overflow problem Date: Tue, 08 Nov 2022 08:48:51 +0000 [thread overview] Message-ID: <bug-107561-4-s05n0l54SX@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-107561-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107561 Aldy Hernandez <aldyh at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|[13 Regression] |[13 Regression] |g++.dg/pr17488.C regression |g++.dg/pr17488.C and |due to -Wstringop-overflow |[g++.dg/warn/Warray-bounds- |problem |16.C -m32] regression due | |to -Wstringop-overflow | |problem --- Comment #2 from Aldy Hernandez <aldyh at gcc dot gnu.org> --- The following test also fails for the same reason: g++.dg/warn/Warray-bounds-16.C -m32 -O2 It is perhaps a better reduced test for the issue: inline void* operator new (__SIZE_TYPE__, void * v) { return v; } struct S { int* p; int m; S (int i) { m = i; p = (int*) new unsigned char [sizeof (int) * m]; for (int i = 0; i < m; i++) new (p + i) int (); /* { dg-bogus "bounds" "pr102690" { xfail *-*-* } } */ } }; S a (0); $ ./cc1plus a.c -fdump-tree-all-details -quiet -I/tmp -O2 -std=gnu++98 -m32 In constructor ‘S::S(int)’, inlined from ‘void __static_initialization_and_destruction_0()’ at a.c:26:7, inlined from ‘(static initializers for a.c)’ at a.c:26:8: a.c:22:24: warning: ‘void* __builtin_memset(void*, int, unsigned int)’ writing 4 or more bytes into a region of size 0 overflows the destination [-Wstringop-overflow=] 22 | new (p + i) int (); /* { dg-bogus "bounds" "pr102690" { xfail *-*-* } } */ | ^ a.c:19:51: note: destination object of size 0 allocated by ‘operator new []’ 19 | p = (int*) new unsigned char [sizeof (int) * m]; | ^ + set +x The ranges for some pointers are now different as early as .waccess1, even though the IL is the same: --- /tmp/a.c.025t.waccess1.orig.805839 2022-11-08 09:46:00.513031310 +0100 +++ /tmp/a.c.025t.waccess1.new.805839 2022-11-08 09:46:00.515031315 +0100 @@ -41,9 +41,9 @@ max_depth: 2 pointer_query cache contents: - 3.0[5]: _3 = _17 (base0); size: unknown + 3.0[5]: _3 = _17 (base0); size: [4, 2147483647] 11.0[1]: this_11(D) = this_11(D); size: unknown - 17.0[3]: _17 = _17 (base0); size: unknown + 17.0[3]: _17 = _17 (base0); size: [4, 2147483647] Similarly by evrp time: -Global Exported: _15 = [irange] unsigned int [0, +INF] NONZERO 0xfffffffc +Global Exported: _15 = [irange] unsigned int [0, 0][4, +INF] NONZERO 0xfffffffc etc etc. The range is correct, as it is the result of a multiplication by a power of 2: _15 = _2 * 4; _15 can never be [1,3].
next prev parent reply other threads:[~2022-11-08 8:49 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-11-07 20:06 [Bug tree-optimization/107561] New: g++.dg/pr17488.C " aldyh at gcc dot gnu.org 2022-11-07 20:10 ` [Bug tree-optimization/107561] [13 Regression] " pinskia at gcc dot gnu.org 2022-11-08 8:31 ` aldyh at gcc dot gnu.org 2022-11-08 8:48 ` aldyh at gcc dot gnu.org [this message] 2022-11-08 9:34 ` [Bug tree-optimization/107561] [13 Regression] g++.dg/pr17488.C and [g++.dg/warn/Warray-bounds-16.C -m32] " rguenth at gcc dot gnu.org 2022-11-08 13:43 ` aldyh at gcc dot gnu.org 2022-11-08 18:27 ` pinskia at gcc dot gnu.org 2022-12-14 15:43 ` [Bug tree-optimization/107561] [13 Regression] g++.dg/pr71488.C " danglin at gcc dot gnu.org 2023-01-13 12:42 ` rguenth at gcc dot gnu.org 2023-02-02 18:53 ` hp at gcc dot gnu.org 2023-02-02 21:03 ` hp at gcc dot gnu.org 2023-02-10 0:42 ` cvs-commit at gcc dot gnu.org 2023-02-27 9:56 ` rguenth at gcc dot gnu.org 2023-02-27 11:18 ` rguenth at gcc dot gnu.org 2023-02-27 12:49 ` rguenth at gcc dot gnu.org 2023-02-27 13:45 ` aldyh at gcc dot gnu.org 2023-02-27 14:38 ` redi at gcc dot gnu.org 2023-02-27 16:16 ` aldyh at gcc dot gnu.org 2023-03-01 14:22 ` rguenth at gcc dot gnu.org 2023-03-01 14:34 ` jakub at gcc dot gnu.org 2023-03-01 14:38 ` rguenth at gcc dot gnu.org 2023-03-01 14:55 ` jakub at gcc dot gnu.org 2023-03-01 14:57 ` jakub at gcc dot gnu.org 2023-03-01 15:55 ` redi at gcc dot gnu.org 2023-03-02 7:51 ` rguenth at gcc dot gnu.org 2023-03-02 7:53 ` rguenth at gcc dot gnu.org 2023-03-29 11:38 ` rguenth at gcc dot gnu.org 2023-03-29 11:41 ` rguenth at gcc dot gnu.org 2023-03-30 11:16 ` cvs-commit at gcc dot gnu.org 2023-03-30 11:17 ` rguenth at gcc dot gnu.org
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