FIXME for merging of e_flags and .gnu.attributes

FIXME for merging of e_flags and .gnu.attributes

[Alan Modra]

Code in the linker, present before the addition of .gnu.attributes
support, results in shared libraries not being considered by BFD when
merging e_flags and .gnu.attributes from input files to the output.
That doesn't seem correct to me, but I don't know enough about all the
various ABIs to change the behaviour with any confidence.  So this
patch merely punts on dynamic objects in merge_private_bfd_data target
functions, with a FIXME for maintainer attention.

I haven't excluded shared libraries from being considered where the
target merge_private_bfd_data (a) already has code dealing with shared
libraries, or (b) where that function just sets the output to the most
constraining arch/mach combination and other fairly trivial merges, or
(c) when the target has no shared library linker support.

In (a) are: arc, arm, aarch64, riscv, sparc.
In (b) are: bpf, cris, csky, m32r, m68k, mn10300, nios2, tilegx,
	    tilepro, vax, visium, xtensa.
In (c) are: bpf, cr16, h8300, iq2000, m32c, m68hc11, m68hc12, mcore,
	    mep, msp430, mt, rl78, rx, v850.

	PR 25882
	* elf32-bfin.c (elf32_bfin_merge_private_bfd_data): Add FIXME.
	* elf32-frv.c (frv_elf_merge_private_bfd_data): Likewise.
	* elfxx-mips.c (_bfd_mips_elf_merge_private_bfd_data): Likewise.
	* elf32-nds32.c (nds32_elf_merge_private_bfd_data): Likewise.
	* elf32-score.c (s3_elf32_score_merge_private_bfd_data): Likewise.
	* elf32-score7.c (s7_elf32_score_merge_private_bfd_data): Likewise.
	* elf32-sh.c (sh_elf_merge_private_data): Likewise.
	* elf32-tic6x.c (elf32_tic6x_merge_attributes): Likewise.
	* elf64-ia64-vms.c (elf64_ia64_merge_private_bfd_data): Likewise.
	* elfnn-ia64.c (elfNN_ia64_merge_private_bfd_data): Likewise.

diff --git a/bfd/elf32-bfin.c b/bfd/elf32-bfin.c
index e5a83ba49a..e6383a782f 100644
--- a/bfd/elf32-bfin.c
+++ b/bfd/elf32-bfin.c
@@ -4755,6 +4755,10 @@ elf32_bfin_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   flagword old_flags, new_flags;
   bfd_boolean error = FALSE;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   new_flags = elf_elfheader (ibfd)->e_flags;
   old_flags = elf_elfheader (obfd)->e_flags;
 
diff --git a/bfd/elf32-frv.c b/bfd/elf32-frv.c
index 056cc93055..d2a18fd564 100644
--- a/bfd/elf32-frv.c
+++ b/bfd/elf32-frv.c
@@ -6344,6 +6344,10 @@ frv_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   char new_opt[80];
   char old_opt[80];
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   new_opt[0] = old_opt[0] = '\0';
   new_flags = elf_elfheader (ibfd)->e_flags;
   old_flags = elf_elfheader (obfd)->e_flags;
diff --git a/bfd/elf32-nds32.c b/bfd/elf32-nds32.c
index fc4d002f0d..6b0b813af0 100644
--- a/bfd/elf32-nds32.c
+++ b/bfd/elf32-nds32.c
@@ -6817,6 +6817,10 @@ nds32_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   flagword out_fpu_config;
   flagword in_fpu_config;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   /* TODO: Revise to use object-attributes instead.  */
   if (!nds32_check_vec_size (ibfd))
     return FALSE;
diff --git a/bfd/elf32-score.c b/bfd/elf32-score.c
index c5e6346e93..d1a910f279 100644
--- a/bfd/elf32-score.c
+++ b/bfd/elf32-score.c
@@ -4021,6 +4021,10 @@ s3_elf32_score_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   if (!_bfd_generic_verify_endian_match (ibfd, info))
     return FALSE;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   in_flags  = elf_elfheader (ibfd)->e_flags;
   out_flags = elf_elfheader (obfd)->e_flags;
 
diff --git a/bfd/elf32-score7.c b/bfd/elf32-score7.c
index 0f647feaeb..ab5e32a29a 100644
--- a/bfd/elf32-score7.c
+++ b/bfd/elf32-score7.c
@@ -3826,6 +3826,10 @@ s7_elf32_score_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   if (!_bfd_generic_verify_endian_match (ibfd, info))
     return FALSE;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   in_flags  = elf_elfheader (ibfd)->e_flags;
   out_flags = elf_elfheader (obfd)->e_flags;
 
diff --git a/bfd/elf32-sh.c b/bfd/elf32-sh.c
index 24e879e4f4..24203e0d55 100644
--- a/bfd/elf32-sh.c
+++ b/bfd/elf32-sh.c
@@ -6028,6 +6028,10 @@ sh_elf_merge_private_data (bfd *ibfd, struct bfd_link_info *info)
 {
   bfd *obfd = info->output_bfd;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   if (! is_sh_elf (ibfd) || ! is_sh_elf (obfd))
     return TRUE;
 
diff --git a/bfd/elf32-tic6x.c b/bfd/elf32-tic6x.c
index 95814d3abf..d07902fe8a 100644
--- a/bfd/elf32-tic6x.c
+++ b/bfd/elf32-tic6x.c
@@ -3724,6 +3724,10 @@ elf32_tic6x_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
   int i;
   int array_align_in, array_align_out, array_expect_in, array_expect_out;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   if (!elf_known_obj_attributes_proc (obfd)[0].i)
     {
       /* This is the first object.  Copy the attributes.  */
diff --git a/bfd/elf64-ia64-vms.c b/bfd/elf64-ia64-vms.c
index d40fa4277a..159698fa07 100644
--- a/bfd/elf64-ia64-vms.c
+++ b/bfd/elf64-ia64-vms.c
@@ -4233,6 +4233,10 @@ elf64_ia64_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   flagword in_flags;
   bfd_boolean ok = TRUE;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   /* Don't even pretend to support mixed-format linking.  */
   if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
       || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
diff --git a/bfd/elfnn-ia64.c b/bfd/elfnn-ia64.c
index cd94158aba..0cdd6b58c9 100644
--- a/bfd/elfnn-ia64.c
+++ b/bfd/elfnn-ia64.c
@@ -4744,6 +4744,10 @@ elfNN_ia64_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   flagword in_flags;
   bfd_boolean ok = TRUE;
 
+  /* FIXME: What should be checked when linking shared libraries?  */
+  if ((ibfd->flags & DYNAMIC) != 0)
+    return TRUE;
+
   if (!is_ia64_elf (ibfd) || !is_ia64_elf (obfd))
     return TRUE;
 
diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
index 2f26d7ae83..9ce205e9cf 100644
--- a/bfd/elfxx-mips.c
+++ b/bfd/elfxx-mips.c
@@ -15767,6 +15767,7 @@ _bfd_mips_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)
   /* Check to see if the input BFD actually contains any sections.  If not,
      then it has no attributes, and its flags may not have been initialized
      either, but it cannot actually cause any incompatibility.  */
+  /* FIXME: This excludes any input shared library from consideration.  */
   for (sec = ibfd->sections; sec != NULL; sec = sec->next)
     {
       /* Ignore synthetic sections and empty .text, .data and .bss sections

-- 
Alan Modra
Australia Development Lab, IBM