Re: [PATCH v3] h8300-elf: ld: Use USER_LABEL_PREFIX when generating linker scripts [REPOST]

[Jan Dubiec <jdx@o2.pl>]

On 16.09.2026 16:58, Simon Marchi wrote:
[...]> Looks like the change was OK'ed by the relevant people.  However, 
could
> you please make the commit message actually describe the change?
> 
> Thanks,
> 
> Simon

I am not sure how the commit message should be posted, so here it is. I 
hope it will not be a problem for whoever commits the patch to copy and 
paste the message below.

/J.D.

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This patch is a spin-off from the following thread: 
https://inbox.sourceware.org/newlib/CAOox84s_SjpbEZsAx9EprDrTxB-bT0pgbavt8NXY7iiph8h6Vg@mail.gmail.com/T/#t 
.

Bare-metal h8300-elf-gcc sets USER_LABEL_PREFIX: 
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/h8300/elf.h;hb=HEAD.
Strangely, ld does not. As a result, ld exports symbols without
a leading underscore, while GCC expects them to have one. For example:

linker scirpt:
[...]
PROVIDE_HIDDEN (__preinit_array_start = .);
[...]

C source code (the compiler adds 3rd underscore):
[...]
extern void (*__preinit_array_start []) (void) __attribute__((weak));
[...]

This can lead to sneaky bugs when the symbol is declared as weak. It
also creates maintenance issues when the C code is intended to be
portable across multiple platforms.

The patch defines USER_LABEL_PREFIX accordingly and updates the linker
and H8/300 simulator test cases to reflect this change.

The corresponding newlib patch has already been posted and accepted: 
https://inbox.sourceware.org/newlib/20260822001114.1564261-1-jdx@o2.pl/T/#u.

Signed-off-by: Jan Dubiec <jdx@o2.pl>
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