I've searched several of the other Wunitialized reports, but without deeper
knowledge, I wasn't able to conclude whether this is a dup.
Note that even if i happens to be zero-initialized, it is only in this
strapped-down testcase. In the program I am hacking, I got an out-of-bound of
roughly 2^31 over an array of 6 elements, pretty deep in a expression template
hierarchy.
================================================================================
//Tested with (-Wall -Wextra):
// * g++-4.3 (Debian 4.3.4-6) 4.3.4
// * g++-4.4 (Debian 4.4.2-9) 4.4.3 20100108 (prerelease)
// * g++ (GCC) 4.5.0 20100306 (experimental)
#include <iostream>
int main () {
int i;
int array[10];
//std::cout << i; // get warning, okay
for (; i<10; ++i) { // no warning
std::cout << i; // no warning
array [i] = i; // no warning, really hurts
}
// sidenote: same results for
// for (int i; i<N; ++i) {...}
}
================================================================================
Full triplets:
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.4-6'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--enable-multiarch --enable-linker-build-id --with-system-zlib
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--enable-nls --with-gxx-include-dir=/usr/include/c++/4.3 --program-suffix=-4.3
--enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.3.4 (Debian 4.3.4-6)
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.4.2-9'
--with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--enable-multiarch --enable-linker-build-id --with-system-zlib
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.4 --program-suffix=-4.4 --enable-nls
--enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc
--with-arch-32=i486 --with-tune=generic --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.4.3 20100108 (prerelease) (Debian 4.4.2-9)
Using built-in specs.
COLLECT_GCC=/usr/local/gcc-4.5-20100306/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/gcc-4.5-20100306/libexec/gcc/x86_64-unknown-linux-gnu/4.5.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --prefix=/usr/local/gcc-4.5-20100306
--enable-languages=c,c++ --enable-threads=posix --with-system-zlib
--enable-__cxa_atexit --disable-checking --disable-nls --disable-multilib
--enable-bootstrap --with-gcc --with-gnu-as --with-gnu-ld --with-gomp
--with-lto
Thread model: posix
gcc version 4.5.0 20100306 (experimental) (GCC)
--
Summary: [g++-4.3..g++-4.5] for-loops are in the way of
Wuninitialized?
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: phresnel at gmail dot com
GCC build triplet: (see details)
GCC host triplet: (see details)
GCC target triplet: (see details)
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43361
