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From: "msebor at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/88518] Function call defeats -Wuninitialized
Date: Tue, 06 Apr 2021 19:59:29 +0000 [thread overview]
Message-ID: <bug-88518-4-4Lzs1UIc6W@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-88518-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88518
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Last reconfirmed| |2021-4-6
Resolution|--- |DUPLICATE
CC| |msebor at gcc dot gnu.org
--- Comment #6 from Martin Sebor <msebor at gcc dot gnu.org> ---
Confirmed as a duplicate of pr60488 (which itself is likely a duplicate of some
older bug). A variable whose address escapes is not considered by the warning.
It sees the following IL:
;; Function f (f, funcdef_no=0, decl_uid=1947, cgraph_uid=1, symbol_order=0)
void f ()
{
long unsigned int i;
long unsigned int i.0_1;
long unsigned int _2;
<bb 2> [local count: 1073741824]:
# .MEM_4 = VDEF <.MEM_3(D)>
h ();
# VUSE <.MEM_4>
i.0_1 = i; <<< i loaded from memory and not considered
_2 = i.0_1 + 1; <<< missing -Wuninitialized
# .MEM_5 = VDEF <.MEM_4>
i = _2;
# .MEM_6 = VDEF <.MEM_5>
g (&i);
# .MEM_7 = VDEF <.MEM_6>
i ={v} {CLOBBER};
# VUSE <.MEM_7>
return;
}
The pointless load persists until the assembly:
f:
.LFB0:
.cfi_startproc
subq $24, %rsp
.cfi_def_cfa_offset 32
call h
leaq 8(%rsp), %rdi <<< i loaded from memory
addq $1, 8(%rsp) <<< i++
call g
addq $24, %rsp
.cfi_def_cfa_offset 8
ret
.cfi_endproc
*** This bug has been marked as a duplicate of bug 60488 ***
parent reply other threads:[~2021-04-06 19:59 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <bug-88518-4@http.gcc.gnu.org/bugzilla/>]
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