[Patch, AARCH64] gc-section support
Venkataramanan Kumar
venkataramanan.kumar@linaro.org
Mon Feb 25 16:37:00 GMT 2013
Hi Yufeng,
I have done the formating changes and used normal diff instaed of cvs diff now.
Attached is the updated patch.
regards,
Venkat.
>
> Hi Venkat,
>
> Thanks for the patch.
>
> Can you please generate the patch using "diff -u -p"? This will make
> the patch easier to review. Also the indent is not consistent with the
> existing style, which is hard tab(s) plus spaces. Can you please
> correct it as well.
>
> Thanks,
> Yufeng
>
> On 02/22/13 17:25, Venkataramanan Kumar wrote:
>> Hi Maintainers,
>>
>> Attached is a small patch that enables gc-section support for AARCH64.
>>
>> In the sweep hook I have handled TLS and GOT related relocs that were
>> already supported in that file.
>>
>> Make check passes along with the gc-section tests.
>>
>> I used the patched binutils to build gcc for aarch64-none-elf target
>> and tested the gcc testsuite in v8 foundation model.
>>
>> Ok for trunk?
>>
>> regards,
>> Venkat,
>>
>>
>> ChangeLog:
>>
>> BFD
>>
>> 2013-02-21 Venkataramanan Kumar<venkataramanan.kumar@linaro.org>
>>
>> * elf64-aarch64.c (elf_backend_can_gc_sections): Enable
>> gc-section support.
>> (elf64_aarch64_gc_sweep_hook): Handle GOT, TLS and PLT related r
> elocs.
>>
>> LD
>>
>> 2013-02-21 Venkataramanan Kumar<venkataramanan.kumar@linaro.org>
>>
>> * lib/ld-lib.exp (check_gc_sections_available): Remove aarch64
>> from list of
>> targets that don't support gc-section.
>>
-------------- next part --------------
diff -x '*CVS*' -u -p -r src/bfd/elf64-aarch64.c src-patch/bfd/elf64-aarch64.c
--- src/bfd/elf64-aarch64.c 2013-02-21 08:32:30.000000000 +0530
+++ src-patch/bfd/elf64-aarch64.c 2013-02-25 20:34:58.137044054 +0530
@@ -4866,8 +4866,8 @@ elf64_aarch64_print_private_bfd_data (bf
return TRUE;
}
-/* Update the got entry reference counts for the section being removed. */
+/* Update the got entry reference counts for the section being removed. */
static bfd_boolean
elf64_aarch64_gc_sweep_hook (bfd *abfd ATTRIBUTE_UNUSED,
struct bfd_link_info *info ATTRIBUTE_UNUSED,
@@ -4875,6 +4875,139 @@ elf64_aarch64_gc_sweep_hook (bfd *abfd A
const Elf_Internal_Rela *
relocs ATTRIBUTE_UNUSED)
{
+ struct elf64_aarch64_link_hash_table *htab;
+ Elf_Internal_Shdr *symtab_hdr;
+ struct elf_link_hash_entry **sym_hashes;
+ bfd_signed_vma *local_got_refcounts;
+ const Elf_Internal_Rela *rel, *relend;
+
+ if (info->relocatable)
+ return TRUE;
+
+ htab = elf64_aarch64_hash_table (info);
+
+ if (htab == NULL)
+ return FALSE;
+
+ elf_section_data (sec)->local_dynrel = NULL;
+
+ symtab_hdr = &elf_symtab_hdr (abfd);
+ sym_hashes = elf_sym_hashes (abfd);
+
+ local_got_refcounts = elf_local_got_refcounts (abfd);
+
+ relend = relocs + sec->reloc_count;
+ for (rel = relocs; rel < relend; rel++)
+ {
+ unsigned long r_symndx;
+ unsigned int r_type;
+ struct elf_link_hash_entry *h = NULL;
+
+ r_symndx = ELF64_R_SYM (rel->r_info);
+
+ if (r_symndx >= symtab_hdr->sh_info)
+ {
+ struct elf64_aarch64_link_hash_entry *eh;
+ struct elf_dyn_relocs **pp;
+ struct elf_dyn_relocs *p;
+
+ h = sym_hashes[r_symndx - symtab_hdr->sh_info];
+ while (h->root.type == bfd_link_hash_indirect
+ || h->root.type == bfd_link_hash_warning)
+ h = (struct elf_link_hash_entry *) h->root.u.i.link;
+ eh = (struct elf64_aarch64_link_hash_entry *) h;
+
+ for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
+ {
+ if (p->sec == sec)
+ {
+ /* Everything must go for SEC. */
+ *pp = p->next;
+ break;
+ }
+ }
+ }
+ else
+ {
+ Elf_Internal_Sym *isym;
+
+ /* A local symbol. */
+ isym = bfd_sym_from_r_symndx (&htab->sym_cache,
+ abfd, r_symndx);
+ if (isym == NULL)
+ return FALSE;
+ }
+
+ r_type = ELF64_R_TYPE (rel->r_info);
+ r_type = aarch64_tls_transition (abfd,info, r_type, h ,r_symndx);
+ switch (r_type)
+ {
+ case R_AARCH64_LD64_GOT_LO12_NC:
+ case R_AARCH64_GOT_LD_PREL19:
+ case R_AARCH64_ADR_GOT_PAGE:
+ case R_AARCH64_TLSGD_ADR_PAGE21:
+ case R_AARCH64_TLSGD_ADD_LO12_NC:
+ case R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
+ case R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
+ case R_AARCH64_TLSLE_ADD_TPREL_LO12:
+ case R_AARCH64_TLSLE_ADD_TPREL_HI12:
+ case R_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
+ case R_AARCH64_TLSLE_MOVW_TPREL_G2:
+ case R_AARCH64_TLSLE_MOVW_TPREL_G1:
+ case R_AARCH64_TLSLE_MOVW_TPREL_G1_NC:
+ case R_AARCH64_TLSLE_MOVW_TPREL_G0:
+ case R_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
+ case R_AARCH64_TLSDESC_ADR_PAGE:
+ case R_AARCH64_TLSDESC_ADD_LO12_NC:
+ case R_AARCH64_TLSDESC_LD64_LO12_NC:
+ if (h != NULL)
+ {
+ if (h->got.refcount > 0)
+ h->got.refcount -= 1;
+ }
+ else if (local_got_refcounts != NULL)
+ {
+ if (local_got_refcounts[r_symndx] > 0)
+ local_got_refcounts[r_symndx] -= 1;
+ }
+ break;
+
+ case R_AARCH64_ADR_PREL_PG_HI21_NC:
+ case R_AARCH64_ADR_PREL_PG_HI21:
+ case R_AARCH64_ADR_PREL_LO21:
+ if (h != NULL && info->executable)
+ {
+ if (h->plt.refcount > 0)
+ h->plt.refcount -= 1;
+ }
+ break;
+
+ case R_AARCH64_CALL26:
+ case R_AARCH64_JUMP26:
+ /* If this is a local symbol then we resolve it
+ directly without creating a PLT entry. */
+ if (h == NULL)
+ continue;
+
+ if (h->plt.refcount > 0)
+ h->plt.refcount -= 1;
+ break;
+
+ case R_AARCH64_ABS64:
+ if (h != NULL && info->executable)
+ {
+ if (h->plt.refcount > 0)
+ h->plt.refcount -= 1;
+ }
+ break;
+
+ default:
+ break;
+
+ }
+
+ }
+
return TRUE;
}
@@ -7049,7 +7182,7 @@ const struct elf_size_info elf64_aarch64
elf64_aarch64_size_info
#define elf_backend_can_refcount 1
-#define elf_backend_can_gc_sections 0
+#define elf_backend_can_gc_sections 1
#define elf_backend_plt_readonly 1
#define elf_backend_want_got_plt 1
#define elf_backend_want_plt_sym 0
diff -x '*CVS*' -u -p -r src/ld/testsuite/lib/ld-lib.exp src-patch/ld/testsuite/lib/ld-lib.exp
--- src/ld/testsuite/lib/ld-lib.exp 2013-02-19 06:40:06.000000000 +0530
+++ src-patch/ld/testsuite/lib/ld-lib.exp 2013-02-25 20:34:46.737044219 +0530
@@ -1518,8 +1518,7 @@ proc check_gc_sections_available { } {
if {![info exists gc_sections_available_saved]} {
# Some targets don't support gc-sections despite whatever's
# advertised by ld's options.
- if {[istarget aarch64*-*-*]
- || [istarget arc-*-*]
+ if {[istarget arc-*-*]
|| [istarget d30v-*-*]
|| [istarget dlx-*-*]
|| [istarget i960-*-*]
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