https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107411
Bug ID: 107411
Summary: trivial-auto-var-init=zero invalid uninitialized
variable warning
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: davidwelch158 at hotmail dot com
Target Milestone: ---
Created attachment 53774
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53774&action=edit
preprocessed reproduction case
Compiling this file
#include <cstdio>
class HostLayer
{
public:
int getError();
};
void queryString(HostLayer& m_host)
{
const auto& error = m_host.getError();
printf("%d\n", error);
}
with the command line on x86-64 Ubuntu 22.04
g++ -Werror=uninitialized -ftrivial-auto-var-init=zero -c OverrideLayer.cpp
and the latest gcc trunk (GCC12 is also affected) produces the warning.
OverrideLayer.cpp: In function ‘void queryString(HostLayer&)’:
OverrideLayer.cpp:12:45: error: ‘D.2933’ is used uninitialized
[-Werror=uninitialized]
12 | const auto& error = m_host.getError();
| ^
OverrideLayer.cpp:12:45: note: ‘D.2933’ was declared here
12 | const auto& error = m_host.getError();
|
which seems to be invalid and also doesn't identify the problem variable.
Compiling with
/home/dw/devel/gcc/install/bin/g++ -Werror=uninitialized -c
OverrideLayer.cpp
finishes without error.
g++ -v
Using built-in specs.
COLLECT_GCC=/home/dw/devel/gcc/install/bin/g++
COLLECT_LTO_WRAPPER=/home/dw/devel/gcc/install/libexec/gcc/x86_64-linux-gnu/13.0.0/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../configure --enable-languages=c,c++
--prefix=/home/dw/devel/gcc/install --enable-shared --enable-linker-build-id
--without-included-gettext --enable-threads=posix --enable-nls
--enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib
--enable-libphobos-checking=release --with-target-system-zlib=auto
--enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet
--with-arch-32=i686 --with-abi=m64 --enable-offload-defaulted
--without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.0.0 20221025 (experimental) (GCC)
lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04.1 LTS
Release: 22.04
Codename: jammy
