On 17/04/2025 07:49, Wasim Khan via Gcc wrote: > Hi, > > I have a custom implementation of memcpy() function and don't want to use > implementation provided by libc.a. > Things works fine with toolchain version 12.3 and my local implementation in > utils.c is considered. > But when I move to toolchain version 14.2 , I am getting below error. > > > Linking ... > /opt/arm-gnu-toolchain-*-aarch64-none-elf/bin/aarch64-none-elf-gcc \ > -nodefaultlibs \ > -nostartfiles \ > -mcpu=cortex-a55 \ > -Wl,--gc-sections \ > -Wl,--build-id=none \ > -T /opt/test.lds \ > -Wl,-Map=/opt/test.map \ > -Wl,--no-warn-rwx-segments \ > /opt/test.o /opt/utils.o \ > -L /opt/arm-gnu-toolchain-*-aarch64-none-elf/aarch64-none-elf/lib \ > -Wl,--start-group -l:libc.a -l:libgcc.a -Wl,--end-group \ > -o /opt/test.elf > > /opt/arm-gnu-toolchain-14.2.rel1-x86_64-aarch64-none-elf/bin/../lib/gcc/aarch64-none-elf/14.2.1/../../../../aarch64-none-elf/bin/ld: > > /opt/arm-gnu-toolchain-14.2.rel1-x86_64-aarch64-none-elf/aarch64-none-elf/lib/libc.a(libc_a-memcpy.o): > in function `memcpy': > /data/jenkins/workspace/GNU-toolchain/arm-14/src/newlib-cygwin/newlib/libc/machine/aarch64/memcpy.S:60: > multiple definition of `memcpy'; /opt/utils.o:/opt/utils.c:247: first > defined here > collect2: error: ld returned 1 exit status > make: *** [Makefile:282: linkobj] Error 1 > > > > Need help on how to use custom implementation of memcpy() (but use all other > standard functions from libc.a). > Also, any idea on why the issue is with 14.2 and not with earlier versions > (like 12.3) ? > > Regards, >
Perhaps your code is calling memmove() as well? The two functions are generally tightly integrated in the C library, especially when memmove() is assuming particular properties of the memcpy implementation. For example, you can't override free without also overriding all the other functions that go with heap management (malloc, realloc, etc). BTW, if you generate a linker map, it should tell you why the libc implementation of memcpy is being pulled in as well. R.
