Created attachment 49453 [details]
-Wself-init alone fails to warn of a pointless assignment

The assignment int a = a; below does not create a warning to let me know that the assignment is pointless even when I use -Winit-self  xor -Wall as per the attached image.  The warning only appears if I enable both options.  This leads to subtle errors in generated  ({ code ...}) constructs that are difficult to debug.  Please add a warning for such pointless assignments that is enabled with -Wall.

#include <stdio.h>
int main(void)
 {int   a = 1;
   {int a = a; // Pointless
    printf("AAAA %d\n", a);
   }
  printf("BBBB %d\n", a);
 }
// AAAA 0
// BBBB 1

GCC details:

gcc -v -save-temps -Winit-self assign.c      
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 10.1.0-2ubuntu1~18.04' --with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-10 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --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 --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-10-eDoCEC/gcc-10-10.1.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-10-eDoCEC/gcc-10-10.1.0/debian/tmp-gcn/usr,hsa --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 10.1.0 (Ubuntu 10.1.0-2ubuntu1~18.04) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Winit-self' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/10/cc1 -E -quiet -v -imultiarch x86_64-linux-gnu assign.c -mtune=generic -march=x86-64 -Winit-self -fpch-preprocess -fasynchronous-unwind-tables -fstack-protector-strong -Wformat -Wformat-security -o assign.i
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/10/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-linux-gnu/10/include
 /usr/local/include
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Winit-self' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/10/cc1 -fpreprocessed assign.i -quiet -dumpbase assign.c -mtune=generic -march=x86-64 -auxbase assign -Winit-self -version -fasynchronous-unwind-tables -fstack-protector-strong -Wformat -Wformat-security -o assign.s
GNU C17 (Ubuntu 10.1.0-2ubuntu1~18.04) version 10.1.0 (x86_64-linux-gnu)
        compiled by GNU C version 10.1.0, GMP version 6.1.2, MPFR version 4.0.1, MPC version 1.1.0, isl version isl-0.19-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C17 (Ubuntu 10.1.0-2ubuntu1~18.04) version 10.1.0 (x86_64-linux-gnu)
        compiled by GNU C version 10.1.0, GMP version 6.1.2, MPFR version 4.0.1, MPC version 1.1.0, isl version isl-0.19-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 797ff541be7d2acc7d0ced3c057e002c
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Winit-self' '-mtune=generic' '-march=x86-64'
 as -v --64 -o assign.o assign.s
GNU assembler version 2.30 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.30
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/10/:/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/10/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/10/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Winit-self' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/10/collect2 -plugin /usr/lib/gcc/x86_64-linux-gnu/10/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper -plugin-opt=-fresolution=assign.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie -z now -z relro /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/Scrt1.o /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/10/crtbeginS.o -L/usr/lib/gcc/x86_64-linux-gnu/10 -L/usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/10/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/10/../../.. assign.o -lgcc --push-state --as-needed -lgcc_s --pop-state -lc -lgcc --push-state --as-needed -lgcc_s --pop-state /usr/lib/gcc/x86_64-linux-gnu/10/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crtn.o
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Winit-self' '-mtune=generic' '-march=x86-64'