https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107885
Bug ID: 107885
Summary: H8/300: libsupc++/hash_bytes.cc fix
shift-count-overflow warning
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: uaa at mx5 dot nisiq.net
Target Milestone: ---
Created attachment 53974
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53974&action=edit
add cast to static_cast<unsigned char>(buf[x])
On building gcc-12.2.0 with newlib-4.1.0 (newlib and libgloss) and
binutils-2.36.1 on Debian-11.5/amd64.
gcc/config/h8300/t-h8300 is modified with:
MULTILIB_OPTIONS = ms/msx mint32
MULTILIB_DIRNAMES = h8300s h8sx int32
to disable building H8 normal mode library.
gcc configuration is:
../configure --target=h8300-unknown-elf --enable-languages=c,c++ \
--prefix=/home/uaa/h8300 --with-newlib --disable-nls --disable-libssp \
--disable-libgomp --disable-libstdcxx-pch \
--disable-libstdcxx-filesystem-ts --with-newlib --disable-wchar_t
libstdc++-v3/libsupc++/hash_bytes.cc has warning,
due to the size of int is 16bit (H8/300 default).
/bin/bash ../libtool --tag CXX --tag disable-shared --mode=compile
/home/uaa/gcc-12.2.0/h8300-unknown-elf/./gcc/xgcc -shared-libgcc
-B/home/uaa/gcc-12.2.0/h8300-unknown-elf/./gcc -nostdinc++
-L/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/src
-L/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/src/.libs
-L/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/libsupc++/.libs
-nostdinc
-B/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/newlib/
-isystem
/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/newlib/targ-include
-isystem /home/uaa/gcc-12.2.0/newlib/libc/include
-B/home/uaa/h8300/h8300-unknown-elf/bin/
-B/home/uaa/h8300/h8300-unknown-elf/lib/ -isystem
/home/uaa/h8300/h8300-unknown-elf/include -isystem
/home/uaa/h8300/h8300-unknown-elf/sys-include -ms
-I/home/uaa/gcc-12.2.0/libstdc++-v3/../libgcc
-I/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/include/h8300-unknown-elf
-I/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/include
-I/home/uaa/gcc-12.2.0/libstdc++-v3/libsupc++ -fno-implicit-templates
-Wall -Wextra -Wwrite-strings -Wcast-qual -Wabi=2
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections
-frandom-seed=hash_bytes.lo -g -O2 -ms -c -o hash_bytes.lo
../../../../../libstdc++-v3/libsupc++/hash_bytes.cc
libtool: compile: /home/uaa/gcc-12.2.0/h8300-unknown-elf/./gcc/xgcc
-shared-libgcc -B/home/uaa/gcc-12.2.0/h8300-unknown-elf/./gcc -nostdinc++
-L/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/src
-L/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/src/.libs
-L/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/libsupc++/.libs
-nostdinc
-B/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/newlib/
-isystem
/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/newlib/targ-include
-isystem /home/uaa/gcc-12.2.0/newlib/libc/include
-B/home/uaa/h8300/h8300-unknown-elf/bin/
-B/home/uaa/h8300/h8300-unknown-elf/lib/ -isystem
/home/uaa/h8300/h8300-unknown-elf/include -isystem
/home/uaa/h8300/h8300-unknown-elf/sys-include -ms
-I/home/uaa/gcc-12.2.0/libstdc++-v3/../libgcc
-I/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/include/h8300-unknown-elf
-I/home/uaa/gcc-12.2.0/h8300-unknown-elf/h8300-unknown-elf/h8300s/libstdc++-v3/include
-I/home/uaa/gcc-12.2.0/libstdc++-v3/libsupc++ -fno-implicit-templates -Wall
-Wextra -Wwrite-strings -Wcast-qual -Wabi=2 -fdiagnostics-show-location=once
-ffunction-sections -fdata-sections -frandom-seed=hash_bytes.lo -g -O2 -ms -c
../../../../../libstdc++-v3/libsupc++/hash_bytes.cc -o hash_bytes.o
../../../../../libstdc++-v3/libsupc++/hash_bytes.cc: In function 'std::size_t
std::_Hash_bytes(const void*, size_t, size_t)':
../../../../../libstdc++-v3/libsupc++/hash_bytes.cc:97:52: warning: left shift
count >= width of type [-Wshift-count-overflow]
97 | hash ^= static_cast<unsigned char>(buf[2]) << 16;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
suggested remedy is attached.
