> -----Original Message-----
> From: Richard Earnshaw (lists) <richard.earns...@arm.com>
> Sent: 17 April 2025 14:57
> To: Wasim Khan <wasim.k...@nxp.com>; gcc-h...@gcc.gnu.org;
> gcc@gcc.gnu.org
> Subject: Re: memcpy issue with arm-gnu-toolchain-14.2.rel1-x86_64-aarch64-
> none-elf
>
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>
> 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.
I am not using memove() anywhere in my code. However, defining custom memove()
solves the problem with 14.2. Thanks!!
I wonder why it is not required with 12.3 , because as per linker map, memcpy()
is coming from my custom implementation and memmove() is coming from libc for
12.3.
.text.memcpy 0x000000002048d1d0 0x20 /opt/test.o
0x000000002048d1d0 memcpy
.text 0x000000002049b240 0xac
/opt/arm-gnu-toolchain-12.3.rel1-x86_64-aarch64-none-elf/aarch64-none-elf/lib/libc.a(libc_a-memmove.o)
0x000000002049b240 memmove
This dependency is something introduced after 12.3 ?
Also, is there any way to know about such dependencies of such functions?
Because compiler does not complaints if custom definitions are ignored .
