Re: [PATCH] LoongArch: Modify inconsistent behavior of ld with --unresolved-symbols=ignore-all

[Xi Ruoyao <xry111@xry111.site>]

On Tue, 2024-02-20 at 10:11 +0800, ticat-fp wrote:
> Ignore errors when producing executable files that reference external symbols defined
> in other files.
> 
> Testcase is:
> resolv.c:
> int main(int argc, char *argv[]) {
>     return argc;
> }
> 
> t.c:
> 
> extern const struct my_struct ms1;
> static const struct my_struct *ms = &ms1;
> 
> t.h:
> typedef struct my_struct {
>     char *str;
>     int i;
> } my_struct;
> 
> Compiling and linking command with:
> gcc t.c -c ; gcc resolv.c -c
> gcc resolv.o t.o -o resolv -Wl,--unresolved-symbols=ignore-all
> 
> Got error as:
> ~/install/usr/bin/ld: t.o:(.data.rel+0x0): undefined reference to `ms1'
> collect2: error: ld returned 1 exit status
> 
> Signed-off-by: ticat-fp <fanpeng@loongson.cn>

Signed-off-by may have a legal implication so generally we should use
the real name here.

Or if this is done during your working time you don't need a Signed-off-
by as the change should be covered by Loongson corporate FSF assignment.

> ---
>  bfd/elfnn-loongarch.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
> index 1895699af06..6b2d5a7164d 100644
> --- a/bfd/elfnn-loongarch.c
> +++ b/bfd/elfnn-loongarch.c
> @@ -2662,6 +2662,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
>        char tls_type;
>        bfd_vma relocation, off, ie_off, desc_off;
>        int i, j;
> +      bool ignored = false;
>  
>        howto = loongarch_elf_rtype_to_howto (input_bfd, r_type);
>        if (howto == NULL || r_type == R_LARCH_GNU_VTINHERIT
> @@ -2703,7 +2704,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
>  	}
>        else
>  	{
> -	  bool warned, ignored;
> +	  bool warned;
>  
>  	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
>  				   r_symndx, symtab_hdr, sym_hashes,
> @@ -2867,7 +2868,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
>  		{
>  		  if (h->dynindx == -1)
>  		    {
> -		      if (h->root.type == bfd_link_hash_undefined)
> +		      if (h->root.type == bfd_link_hash_undefined && !ignored)
>  			(*info->callbacks->undefined_symbol)
>  			  (info, name, input_bfd, input_section,
>  			   rel->r_offset, true);

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University