bfd/elfnn-riscv.c

/* RISC-V-specific support for NN-bit ELF.
   Copyright (C) 2011-2019 Free Software Foundation, Inc.

   Contributed by Andrew Waterman (andrew@sifive.com).
   Based on TILE-Gx and MIPS targets.

   This file is part of BFD, the Binary File Descriptor library.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING3. If not,
   see <http://www.gnu.org/licenses/>.  */

/* This file handles RISC-V ELF targets.  */

#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "bfdlink.h"
#include "genlink.h"
#include "elf-bfd.h"
#include "elfxx-riscv.h"
#include "elf/riscv.h"
#include "opcode/riscv.h"

/* Internal relocations used exclusively by the relaxation pass.  */
#define R_RISCV_DELETE (R_RISCV_max + 1)

#define ARCH_SIZE NN

#define MINUS_ONE ((bfd_vma)0 - 1)

#define RISCV_ELF_LOG_WORD_BYTES (ARCH_SIZE == 32 ? 2 : 3)

#define RISCV_ELF_WORD_BYTES (1 << RISCV_ELF_LOG_WORD_BYTES)

/* The name of the dynamic interpreter.  This is put in the .interp
   section.  */

#define ELF64_DYNAMIC_INTERPRETER "/lib/ld.so.1"
#define ELF32_DYNAMIC_INTERPRETER "/lib32/ld.so.1"

#define ELF_ARCH			bfd_arch_riscv
#define ELF_TARGET_ID			RISCV_ELF_DATA
#define ELF_MACHINE_CODE		EM_RISCV
#define ELF_MAXPAGESIZE			0x1000
#define ELF_COMMONPAGESIZE		0x1000

/* RISC-V ELF linker hash entry.  */

struct riscv_elf_link_hash_entry
{
  struct elf_link_hash_entry elf;

  /* Track dynamic relocs copied for this symbol.  */
  struct elf_dyn_relocs *dyn_relocs;

#define GOT_UNKNOWN     0
#define GOT_NORMAL      1
#define GOT_TLS_GD      2
#define GOT_TLS_IE      4
#define GOT_TLS_LE      8
  char tls_type;
};

#define riscv_elf_hash_entry(ent) \
  ((struct riscv_elf_link_hash_entry *)(ent))

struct _bfd_riscv_elf_obj_tdata
{
  struct elf_obj_tdata root;

  /* tls_type for each local got entry.  */
  char *local_got_tls_type;
};

#define _bfd_riscv_elf_tdata(abfd) \
  ((struct _bfd_riscv_elf_obj_tdata *) (abfd)->tdata.any)

#define _bfd_riscv_elf_local_got_tls_type(abfd) \
  (_bfd_riscv_elf_tdata (abfd)->local_got_tls_type)

#define _bfd_riscv_elf_tls_type(abfd, h, symndx)		\
  (*((h) != NULL ? &riscv_elf_hash_entry (h)->tls_type		\
     : &_bfd_riscv_elf_local_got_tls_type (abfd) [symndx]))

#define is_riscv_elf(bfd)				\
  (bfd_get_flavour (bfd) == bfd_target_elf_flavour	\
   && elf_tdata (bfd) != NULL				\
   && elf_object_id (bfd) == RISCV_ELF_DATA)

#include "elf/common.h"
#include "elf/internal.h"

struct riscv_elf_link_hash_table
{
  struct elf_link_hash_table elf;

  /* Short-cuts to get to dynamic linker sections.  */
  asection *sdyntdata;

  /* Small local sym to section mapping cache.  */
  struct sym_cache sym_cache;

  /* The max alignment of output sections.  */
  bfd_vma max_alignment;
};


/* Get the RISC-V ELF linker hash table from a link_info structure.  */
#define riscv_elf_hash_table(p) \
  (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
  == RISCV_ELF_DATA ? ((struct riscv_elf_link_hash_table *) ((p)->hash)) : NULL)

static bfd_boolean
riscv_info_to_howto_rela (bfd *abfd,
			  arelent *cache_ptr,
			  Elf_Internal_Rela *dst)
{
  cache_ptr->howto = riscv_elf_rtype_to_howto (abfd, ELFNN_R_TYPE (dst->r_info));
  return cache_ptr->howto != NULL;
}

static void
riscv_elf_append_rela (bfd *abfd, asection *s, Elf_Internal_Rela *rel)
{
  const struct elf_backend_data *bed;
  bfd_byte *loc;

  bed = get_elf_backend_data (abfd);
  loc = s->contents + (s->reloc_count++ * bed->s->sizeof_rela);
  bed->s->swap_reloca_out (abfd, rel, loc);
}

/* PLT/GOT stuff.  */

#define PLT_HEADER_INSNS 8
#define PLT_ENTRY_INSNS 4
#define PLT_HEADER_SIZE (PLT_HEADER_INSNS * 4)
#define PLT_ENTRY_SIZE (PLT_ENTRY_INSNS * 4)

#define GOT_ENTRY_SIZE RISCV_ELF_WORD_BYTES

#define GOTPLT_HEADER_SIZE (2 * GOT_ENTRY_SIZE)

#define sec_addr(sec) ((sec)->output_section->vma + (sec)->output_offset)

static bfd_vma
riscv_elf_got_plt_val (bfd_vma plt_index, struct bfd_link_info *info)
{
  return sec_addr (riscv_elf_hash_table (info)->elf.sgotplt)
	 + GOTPLT_HEADER_SIZE + (plt_index * GOT_ENTRY_SIZE);
}

#if ARCH_SIZE == 32
# define MATCH_LREG MATCH_LW
#else
# define MATCH_LREG MATCH_LD
#endif

/* Generate a PLT header.  */

static bfd_boolean
riscv_make_plt_header (bfd *output_bfd, bfd_vma gotplt_addr, bfd_vma addr,
		       uint32_t *entry)
{
  bfd_vma gotplt_offset_high = RISCV_PCREL_HIGH_PART (gotplt_addr, addr);
  bfd_vma gotplt_offset_low = RISCV_PCREL_LOW_PART (gotplt_addr, addr);

  /* RVE has no t3 register, so this won't work, and is not supported.  */
  if (elf_elfheader (output_bfd)->e_flags & EF_RISCV_RVE)
    {
      _bfd_error_handler (_("%pB: warning: RVE PLT generation not supported"),
			  output_bfd);
      return FALSE;
    }

  /* auipc  t2, %hi(.got.plt)
     sub    t1, t1, t3		     # shifted .got.plt offset + hdr size + 12
     l[w|d] t3, %lo(.got.plt)(t2)    # _dl_runtime_resolve
     addi   t1, t1, -(hdr size + 12) # shifted .got.plt offset
     addi   t0, t2, %lo(.got.plt)    # &.got.plt
     srli   t1, t1, log2(16/PTRSIZE) # .got.plt offset
     l[w|d] t0, PTRSIZE(t0)	     # link map
     jr	    t3 */

  entry[0] = RISCV_UTYPE (AUIPC, X_T2, gotplt_offset_high);
  entry[1] = RISCV_RTYPE (SUB, X_T1, X_T1, X_T3);
  entry[2] = RISCV_ITYPE (LREG, X_T3, X_T2, gotplt_offset_low);
  entry[3] = RISCV_ITYPE (ADDI, X_T1, X_T1, -(PLT_HEADER_SIZE + 12));
  entry[4] = RISCV_ITYPE (ADDI, X_T0, X_T2, gotplt_offset_low);
  entry[5] = RISCV_ITYPE (SRLI, X_T1, X_T1, 4 - RISCV_ELF_LOG_WORD_BYTES);
  entry[6] = RISCV_ITYPE (LREG, X_T0, X_T0, RISCV_ELF_WORD_BYTES);
  entry[7] = RISCV_ITYPE (JALR, 0, X_T3, 0);

  return TRUE;
}

/* Generate a PLT entry.  */

static bfd_boolean
riscv_make_plt_entry (bfd *output_bfd, bfd_vma got, bfd_vma addr,
		      uint32_t *entry)
{
  /* RVE has no t3 register, so this won't work, and is not supported.  */
  if (elf_elfheader (output_bfd)->e_flags & EF_RISCV_RVE)
    {
      _bfd_error_handler (_("%pB: warning: RVE PLT generation not supported"),
			  output_bfd);
      return FALSE;
    }

  /* auipc  t3, %hi(.got.plt entry)
     l[w|d] t3, %lo(.got.plt entry)(t3)
     jalr   t1, t3
     nop */

  entry[0] = RISCV_UTYPE (AUIPC, X_T3, RISCV_PCREL_HIGH_PART (got, addr));
  entry[1] = RISCV_ITYPE (LREG,  X_T3, X_T3, RISCV_PCREL_LOW_PART (got, addr));
  entry[2] = RISCV_ITYPE (JALR, X_T1, X_T3, 0);
  entry[3] = RISCV_NOP;

  return TRUE;
}

/* Create an entry in an RISC-V ELF linker hash table.  */

static struct bfd_hash_entry *
link_hash_newfunc (struct bfd_hash_entry *entry,
		   struct bfd_hash_table *table, const char *string)
{
  /* Allocate the structure if it has not already been allocated by a
     subclass.  */
  if (entry == NULL)
    {
      entry =
	bfd_hash_allocate (table,
			   sizeof (struct riscv_elf_link_hash_entry));
      if (entry == NULL)
	return entry;
    }

  /* Call the allocation method of the superclass.  */
  entry = _bfd_elf_link_hash_newfunc (entry, table, string);
  if (entry != NULL)
    {
      struct riscv_elf_link_hash_entry *eh;

      eh = (struct riscv_elf_link_hash_entry *) entry;
      eh->dyn_relocs = NULL;
      eh->tls_type = GOT_UNKNOWN;
    }

  return entry;
}

/* Create a RISC-V ELF linker hash table.  */

static struct bfd_link_hash_table *
riscv_elf_link_hash_table_create (bfd *abfd)
{
  struct riscv_elf_link_hash_table *ret;
  bfd_size_type amt = sizeof (struct riscv_elf_link_hash_table);

  ret = (struct riscv_elf_link_hash_table *) bfd_zmalloc (amt);
  if (ret == NULL)
    return NULL;

  if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc,
				      sizeof (struct riscv_elf_link_hash_entry),
				      RISCV_ELF_DATA))
    {
      free (ret);
      return NULL;
    }

  ret->max_alignment = (bfd_vma) -1;
  return &ret->elf.root;
}

/* Create the .got section.  */

static bfd_boolean
riscv_elf_create_got_section (bfd *abfd, struct bfd_link_info *info)
{
  flagword flags;
  asection *s, *s_got;
  struct elf_link_hash_entry *h;
  const struct elf_backend_data *bed = get_elf_backend_data (abfd);
  struct elf_link_hash_table *htab = elf_hash_table (info);

  /* This function may be called more than once.  */
  if (htab->sgot != NULL)
    return TRUE;

  flags = bed->dynamic_sec_flags;

  s = bfd_make_section_anyway_with_flags (abfd,
					  (bed->rela_plts_and_copies_p
					   ? ".rela.got" : ".rel.got"),
					  (bed->dynamic_sec_flags
					   | SEC_READONLY));
  if (s == NULL
      || !bfd_set_section_alignment (s, bed->s->log_file_align))
    return FALSE;
  htab->srelgot = s;

  s = s_got = bfd_make_section_anyway_with_flags (abfd, ".got", flags);
  if (s == NULL
      || !bfd_set_section_alignment (s, bed->s->log_file_align))
    return FALSE;
  htab->sgot = s;

  /* The first bit of the global offset table is the header.  */
  s->size += bed->got_header_size;

  if (bed->want_got_plt)
    {
      s = bfd_make_section_anyway_with_flags (abfd, ".got.plt", flags);
      if (s == NULL
	  || !bfd_set_section_alignment (s, bed->s->log_file_align))
	return FALSE;
      htab->sgotplt = s;

      /* Reserve room for the header.  */
      s->size += GOTPLT_HEADER_SIZE;
    }

  if (bed->want_got_sym)
    {
      /* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
	 section.  We don't do this in the linker script because we don't want
	 to define the symbol if we are not creating a global offset
	 table.  */
      h = _bfd_elf_define_linkage_sym (abfd, info, s_got,
				       "_GLOBAL_OFFSET_TABLE_");
      elf_hash_table (info)->hgot = h;
      if (h == NULL)
	return FALSE;
    }

  return TRUE;
}

/* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and
   .rela.bss sections in DYNOBJ, and set up shortcuts to them in our
   hash table.  */

static bfd_boolean
riscv_elf_create_dynamic_sections (bfd *dynobj,
				   struct bfd_link_info *info)
{
  struct riscv_elf_link_hash_table *htab;

  htab = riscv_elf_hash_table (info);
  BFD_ASSERT (htab != NULL);

  if (!riscv_elf_create_got_section (dynobj, info))
    return FALSE;

  if (!_bfd_elf_create_dynamic_sections (dynobj, info))
    return FALSE;

  if (!bfd_link_pic (info))
    {
      /* Technically, this section doesn't have contents.  It is used as the
	 target of TLS copy relocs, to copy TLS data from shared libraries into
	 the executable.  However, if we don't mark it as loadable, then it
	 matches the IS_TBSS test in ldlang.c, and there is no run-time address
	 space allocated for it even though it has SEC_ALLOC.  That test is
	 correct for .tbss, but not correct for this section.  There is also
	 a second problem that having a section with no contents can only work
	 if it comes after all sections with contents in the same segment,
	 but the linker script does not guarantee that.  This is just mixed in
	 with other .tdata.* sections.  We can fix both problems by lying and
	 saying that there are contents.  This section is expected to be small
	 so this should not cause a significant extra program startup cost.  */
      htab->sdyntdata =
	bfd_make_section_anyway_with_flags (dynobj, ".tdata.dyn",
					    (SEC_ALLOC | SEC_THREAD_LOCAL
					     | SEC_LOAD | SEC_DATA
					     | SEC_HAS_CONTENTS
					     | SEC_LINKER_CREATED));
    }

  if (!htab->elf.splt || !htab->elf.srelplt || !htab->elf.sdynbss
      || (!bfd_link_pic (info) && (!htab->elf.srelbss || !htab->sdyntdata)))
    abort ();

  return TRUE;
}

/* Copy the extra info we tack onto an elf_link_hash_entry.  */

static void
riscv_elf_copy_indirect_symbol (struct bfd_link_info *info,
				struct elf_link_hash_entry *dir,
				struct elf_link_hash_entry *ind)
{
  struct riscv_elf_link_hash_entry *edir, *eind;

  edir = (struct riscv_elf_link_hash_entry *) dir;
  eind = (struct riscv_elf_link_hash_entry *) ind;

  if (eind->dyn_relocs != NULL)
    {
      if (edir->dyn_relocs != NULL)
	{
	  struct elf_dyn_relocs **pp;
	  struct elf_dyn_relocs *p;

	  /* Add reloc counts against the indirect sym to the direct sym
	     list.  Merge any entries against the same section.  */
	  for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
	    {
	      struct elf_dyn_relocs *q;

	      for (q = edir->dyn_relocs; q != NULL; q = q->next)
		if (q->sec == p->sec)
		  {
		    q->pc_count += p->pc_count;
		    q->count += p->count;
		    *pp = p->next;
		    break;
		  }
	      if (q == NULL)
		pp = &p->next;
	    }
	  *pp = edir->dyn_relocs;
	}

      edir->dyn_relocs = eind->dyn_relocs;
      eind->dyn_relocs = NULL;
    }

  if (ind->root.type == bfd_link_hash_indirect
      && dir->got.refcount <= 0)
    {
      edir->tls_type = eind->tls_type;
      eind->tls_type = GOT_UNKNOWN;
    }
  _bfd_elf_link_hash_copy_indirect (info, dir, ind);
}

static bfd_boolean
riscv_elf_record_tls_type (bfd *abfd, struct elf_link_hash_entry *h,
			   unsigned long symndx, char tls_type)
{
  char *new_tls_type = &_bfd_riscv_elf_tls_type (abfd, h, symndx);

  *new_tls_type |= tls_type;
  if ((*new_tls_type & GOT_NORMAL) && (*new_tls_type & ~GOT_NORMAL))
    {
      (*_bfd_error_handler)
	(_("%pB: `%s' accessed both as normal and thread local symbol"),
	 abfd, h ? h->root.root.string : "<local>");
      return FALSE;
    }
  return TRUE;
}

static bfd_boolean
riscv_elf_record_got_reference (bfd *abfd, struct bfd_link_info *info,
				struct elf_link_hash_entry *h, long symndx)
{
  struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
  Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr;

  if (htab->elf.sgot == NULL)
    {
      if (!riscv_elf_create_got_section (htab->elf.dynobj, info))
	return FALSE;
    }

  if (h != NULL)
    {
      h->got.refcount += 1;
      return TRUE;
    }

  /* This is a global offset table entry for a local symbol.  */
  if (elf_local_got_refcounts (abfd) == NULL)
    {
      bfd_size_type size = symtab_hdr->sh_info * (sizeof (bfd_vma) + 1);
      if (!(elf_local_got_refcounts (abfd) = bfd_zalloc (abfd, size)))
	return FALSE;
      _bfd_riscv_elf_local_got_tls_type (abfd)
	= (char *) (elf_local_got_refcounts (abfd) + symtab_hdr->sh_info);
    }
  elf_local_got_refcounts (abfd) [symndx] += 1;

  return TRUE;
}

static bfd_boolean
bad_static_reloc (bfd *abfd, unsigned r_type, struct elf_link_hash_entry *h)
{
  reloc_howto_type * r = riscv_elf_rtype_to_howto (abfd, r_type);

  (*_bfd_error_handler)
    (_("%pB: relocation %s against `%s' can not be used when making a shared "
       "object; recompile with -fPIC"),
     abfd, r ? r->name : _("<unknown>"),
     h != NULL ? h->root.root.string : "a local symbol");
  bfd_set_error (bfd_error_bad_value);
  return FALSE;
}
/* Look through the relocs for a section during the first phase, and
   allocate space in the global offset table or procedure linkage
   table.  */

static bfd_boolean
riscv_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
			asection *sec, const Elf_Internal_Rela *relocs)
{
  struct riscv_elf_link_hash_table *htab;
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes;
  const Elf_Internal_Rela *rel;
  asection *sreloc = NULL;

  if (bfd_link_relocatable (info))
    return TRUE;

  htab = riscv_elf_hash_table (info);
  symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (abfd);

  if (htab->elf.dynobj == NULL)
    htab->elf.dynobj = abfd;

  for (rel = relocs; rel < relocs + sec->reloc_count; rel++)
    {
      unsigned int r_type;
      unsigned int r_symndx;
      struct elf_link_hash_entry *h;

      r_symndx = ELFNN_R_SYM (rel->r_info);
      r_type = ELFNN_R_TYPE (rel->r_info);

      if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
	{
	  (*_bfd_error_handler) (_("%pB: bad symbol index: %d"),
				 abfd, r_symndx);
	  return FALSE;
	}

      if (r_symndx < symtab_hdr->sh_info)
	h = NULL;
      else
	{
	  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;
	}

      switch (r_type)
	{
	case R_RISCV_TLS_GD_HI20:
	  if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
	      || !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_GD))
	    return FALSE;
	  break;

	case R_RISCV_TLS_GOT_HI20:
	  if (bfd_link_pic (info))
	    info->flags |= DF_STATIC_TLS;
	  if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
	      || !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_IE))
	    return FALSE;
	  break;

	case R_RISCV_GOT_HI20:
	  if (!riscv_elf_record_got_reference (abfd, info, h, r_symndx)
	      || !riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_NORMAL))
	    return FALSE;
	  break;

	case R_RISCV_CALL_PLT:
	  /* This symbol requires a procedure linkage table entry.  We
	     actually build the entry in adjust_dynamic_symbol,
	     because this might be a case of linking PIC code without
	     linking in any dynamic objects, in which case we don't
	     need to generate a procedure linkage table after all.  */

	  if (h != NULL)
	    {
	      h->needs_plt = 1;
	      h->plt.refcount += 1;
	    }
	  break;

	case R_RISCV_CALL:
	case R_RISCV_JAL:
	case R_RISCV_BRANCH:
	case R_RISCV_RVC_BRANCH:
	case R_RISCV_RVC_JUMP:
	case R_RISCV_PCREL_HI20:
	  /* In shared libraries, these relocs are known to bind locally.  */
	  if (bfd_link_pic (info))
	    break;
	  goto static_reloc;

	case R_RISCV_TPREL_HI20:
	  if (!bfd_link_executable (info))
	    return bad_static_reloc (abfd, r_type, h);
	  if (h != NULL)
	    riscv_elf_record_tls_type (abfd, h, r_symndx, GOT_TLS_LE);
	  goto static_reloc;

	case R_RISCV_HI20:
	  if (bfd_link_pic (info))
	    return bad_static_reloc (abfd, r_type, h);
	  /* Fall through.  */

	case R_RISCV_COPY:
	case R_RISCV_JUMP_SLOT:
	case R_RISCV_RELATIVE:
	case R_RISCV_64:
	case R_RISCV_32:
	  /* Fall through.  */

	static_reloc:
	  /* This reloc might not bind locally.  */
	  if (h != NULL)
	    h->non_got_ref = 1;

	  if (h != NULL && !bfd_link_pic (info))
	    {
	      /* We may need a .plt entry if the function this reloc
		 refers to is in a shared lib.  */
	      h->plt.refcount += 1;
	    }

	  /* If we are creating a shared library, and this is a reloc
	     against a global symbol, or a non PC relative reloc
	     against a local symbol, then we need to copy the reloc
	     into the shared library.  However, if we are linking with
	     -Bsymbolic, we do not need to copy a reloc against a
	     global symbol which is defined in an object we are
	     including in the link (i.e., DEF_REGULAR is set).  At
	     this point we have not seen all the input files, so it is
	     possible that DEF_REGULAR is not set now but will be set
	     later (it is never cleared).  In case of a weak definition,
	     DEF_REGULAR may be cleared later by a strong definition in
	     a shared library.  We account for that possibility below by
	     storing information in the relocs_copied field of the hash
	     table entry.  A similar situation occurs when creating
	     shared libraries and symbol visibility changes render the
	     symbol local.

	     If on the other hand, we are creating an executable, we
	     may need to keep relocations for symbols satisfied by a
	     dynamic library if we manage to avoid copy relocs for the
	     symbol.  */
	  reloc_howto_type * r = riscv_elf_rtype_to_howto (abfd, r_type);

	  if ((bfd_link_pic (info)
	       && (sec->flags & SEC_ALLOC) != 0
	       && ((r != NULL && ! r->pc_relative)
		   || (h != NULL
		       && (! info->symbolic
			   || h->root.type == bfd_link_hash_defweak
			   || !h->def_regular))))
	      || (!bfd_link_pic (info)
		  && (sec->flags & SEC_ALLOC) != 0
		  && h != NULL
		  && (h->root.type == bfd_link_hash_defweak
		      || !h->def_regular)))
	    {
	      struct elf_dyn_relocs *p;
	      struct elf_dyn_relocs **head;

	      /* When creating a shared object, we must copy these
		 relocs into the output file.  We create a reloc
		 section in dynobj and make room for the reloc.  */
	      if (sreloc == NULL)
		{
		  sreloc = _bfd_elf_make_dynamic_reloc_section
		    (sec, htab->elf.dynobj, RISCV_ELF_LOG_WORD_BYTES,
		    abfd, /*rela?*/ TRUE);

		  if (sreloc == NULL)
		    return FALSE;
		}

	      /* If this is a global symbol, we count the number of
		 relocations we need for this symbol.  */
	      if (h != NULL)
		head = &((struct riscv_elf_link_hash_entry *) h)->dyn_relocs;
	      else
		{
		  /* Track dynamic relocs needed for local syms too.
		     We really need local syms available to do this
		     easily.  Oh well.  */

		  asection *s;
		  void *vpp;
		  Elf_Internal_Sym *isym;

		  isym = bfd_sym_from_r_symndx (&htab->sym_cache,
						abfd, r_symndx);
		  if (isym == NULL)
		    return FALSE;

		  s = bfd_section_from_elf_index (abfd, isym->st_shndx);
		  if (s == NULL)
		    s = sec;

		  vpp = &elf_section_data (s)->local_dynrel;
		  head = (struct elf_dyn_relocs **) vpp;
		}

	      p = *head;
	      if (p == NULL || p->sec != sec)
		{
		  bfd_size_type amt = sizeof *p;
		  p = ((struct elf_dyn_relocs *)
		       bfd_alloc (htab->elf.dynobj, amt));
		  if (p == NULL)
		    return FALSE;
		  p->next = *head;
		  *head = p;
		  p->sec = sec;
		  p->count = 0;
		  p->pc_count = 0;
		}

	      p->count += 1;
	      p->pc_count += r == NULL ? 0 : r->pc_relative;
	    }

	  break;

	case R_RISCV_GNU_VTINHERIT:
	  if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
	    return FALSE;
	  break;

	case R_RISCV_GNU_VTENTRY:
	  if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
	    return FALSE;
	  break;

	default:
	  break;
	}
    }

  return TRUE;
}

static asection *
riscv_elf_gc_mark_hook (asection *sec,
			struct bfd_link_info *info,
			Elf_Internal_Rela *rel,
			struct elf_link_hash_entry *h,
			Elf_Internal_Sym *sym)
{
  if (h != NULL)
    switch (ELFNN_R_TYPE (rel->r_info))
      {
      case R_RISCV_GNU_VTINHERIT:
      case R_RISCV_GNU_VTENTRY:
	return NULL;
      }

  return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
}

/* Find dynamic relocs for H that apply to read-only sections.  */

static asection *
readonly_dynrelocs (struct elf_link_hash_entry *h)
{
  struct elf_dyn_relocs *p;

  for (p = riscv_elf_hash_entry (h)->dyn_relocs; p != NULL; p = p->next)
    {
      asection *s = p->sec->output_section;

      if (s != NULL && (s->flags & SEC_READONLY) != 0)
	return p->sec;
    }
  return NULL;
}

/* Adjust a symbol defined by a dynamic object and referenced by a
   regular object.  The current definition is in some section of the
   dynamic object, but we're not including those sections.  We have to
   change the definition to something the rest of the link can
   understand.  */

static bfd_boolean
riscv_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
				 struct elf_link_hash_entry *h)
{
  struct riscv_elf_link_hash_table *htab;
  struct riscv_elf_link_hash_entry * eh;
  bfd *dynobj;
  asection *s, *srel;

  htab = riscv_elf_hash_table (info);
  BFD_ASSERT (htab != NULL);

  dynobj = htab->elf.dynobj;

  /* Make sure we know what is going on here.  */
  BFD_ASSERT (dynobj != NULL
	      && (h->needs_plt
		  || h->type == STT_GNU_IFUNC
		  || h->is_weakalias
		  || (h->def_dynamic
		      && h->ref_regular
		      && !h->def_regular)));

  /* If this is a function, put it in the procedure linkage table.  We
     will fill in the contents of the procedure linkage table later
     (although we could actually do it here).  */
  if (h->type == STT_FUNC || h->type == STT_GNU_IFUNC || h->needs_plt)
    {
      if (h->plt.refcount <= 0
	  || SYMBOL_CALLS_LOCAL (info, h)
	  || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
	      && h->root.type == bfd_link_hash_undefweak))
	{
	  /* This case can occur if we saw a R_RISCV_CALL_PLT reloc in an
	     input file, but the symbol was never referred to by a dynamic
	     object, or if all references were garbage collected.  In such
	     a case, we don't actually need to build a PLT entry.  */
	  h->plt.offset = (bfd_vma) -1;
	  h->needs_plt = 0;
	}

      return TRUE;
    }
  else
    h->plt.offset = (bfd_vma) -1;

  /* If this is a weak symbol, and there is a real definition, the
     processor independent code will have arranged for us to see the
     real definition first, and we can just use the same value.  */
  if (h->is_weakalias)
    {
      struct elf_link_hash_entry *def = weakdef (h);
      BFD_ASSERT (def->root.type == bfd_link_hash_defined);
      h->root.u.def.section = def->root.u.def.section;
      h->root.u.def.value = def->root.u.def.value;
      return TRUE;
    }

  /* This is a reference to a symbol defined by a dynamic object which
     is not a function.  */

  /* If we are creating a shared library, we must presume that the
     only references to the symbol are via the global offset table.
     For such cases we need not do anything here; the relocations will
     be handled correctly by relocate_section.  */
  if (bfd_link_pic (info))
    return TRUE;

  /* If there are no references to this symbol that do not use the
     GOT, we don't need to generate a copy reloc.  */
  if (!h->non_got_ref)
    return TRUE;

  /* If -z nocopyreloc was given, we won't generate them either.  */
  if (info->nocopyreloc)
    {
      h->non_got_ref = 0;
      return TRUE;
    }

  /* If we don't find any dynamic relocs in read-only sections, then
     we'll be keeping the dynamic relocs and avoiding the copy reloc.  */
  if (!readonly_dynrelocs (h))
    {
      h->non_got_ref = 0;
      return TRUE;
    }

  /* We must allocate the symbol in our .dynbss section, which will
     become part of the .bss section of the executable.  There will be
     an entry for this symbol in the .dynsym section.  The dynamic
     object will contain position independent code, so all references
     from the dynamic object to this symbol will go through the global
     offset table.  The dynamic linker will use the .dynsym entry to
     determine the address it must put in the global offset table, so
     both the dynamic object and the regular object will refer to the
     same memory location for the variable.  */

  /* We must generate a R_RISCV_COPY reloc to tell the dynamic linker
     to copy the initial value out of the dynamic object and into the
     runtime process image.  We need to remember the offset into the
     .rel.bss section we are going to use.  */
  eh = (struct riscv_elf_link_hash_entry *) h;
  if (eh->tls_type & ~GOT_NORMAL)
    {
      s = htab->sdyntdata;
      srel = htab->elf.srelbss;
    }
  else if ((h->root.u.def.section->flags & SEC_READONLY) != 0)
    {
      s = htab->elf.sdynrelro;
      srel = htab->elf.sreldynrelro;
    }
  else
    {
      s = htab->elf.sdynbss;
      srel = htab->elf.srelbss;
    }
  if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
    {
      srel->size += sizeof (ElfNN_External_Rela);
      h->needs_copy = 1;
    }

  return _bfd_elf_adjust_dynamic_copy (info, h, s);
}

/* Allocate space in .plt, .got and associated reloc sections for
   dynamic relocs.  */

static bfd_boolean
allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
{
  struct bfd_link_info *info;
  struct riscv_elf_link_hash_table *htab;
  struct riscv_elf_link_hash_entry *eh;
  struct elf_dyn_relocs *p;

  if (h->root.type == bfd_link_hash_indirect)
    return TRUE;

  info = (struct bfd_link_info *) inf;
  htab = riscv_elf_hash_table (info);
  BFD_ASSERT (htab != NULL);

  if (htab->elf.dynamic_sections_created
      && h->plt.refcount > 0)
    {
      /* Make sure this symbol is output as a dynamic symbol.
	 Undefined weak syms won't yet be marked as dynamic.  */
      if (h->dynindx == -1
	  && !h->forced_local)
	{
	  if (! bfd_elf_link_record_dynamic_symbol (info, h))
	    return FALSE;
	}

      if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, bfd_link_pic (info), h))
	{
	  asection *s = htab->elf.splt;

	  if (s->size == 0)
	    s->size = PLT_HEADER_SIZE;

	  h->plt.offset = s->size;

	  /* Make room for this entry.  */
	  s->size += PLT_ENTRY_SIZE;

	  /* We also need to make an entry in the .got.plt section.  */
	  htab->elf.sgotplt->size += GOT_ENTRY_SIZE;

	  /* We also need to make an entry in the .rela.plt section.  */
	  htab->elf.srelplt->size += sizeof (ElfNN_External_Rela);

	  /* If this symbol is not defined in a regular file, and we are
	     not generating a shared library, then set the symbol to this
	     location in the .plt.  This is required to make function
	     pointers compare as equal between the normal executable and
	     the shared library.  */
	  if (! bfd_link_pic (info)
	      && !h->def_regular)
	    {
	      h->root.u.def.section = s;
	      h->root.u.def.value = h->plt.offset;
	    }
	}
      else
	{
	  h->plt.offset = (bfd_vma) -1;
	  h->needs_plt = 0;
	}
    }
  else
    {
      h->plt.offset = (bfd_vma) -1;
      h->needs_plt = 0;
    }

  if (h->got.refcount > 0)
    {
      asection *s;
      bfd_boolean dyn;
      int tls_type = riscv_elf_hash_entry (h)->tls_type;

      /* Make sure this symbol is output as a dynamic symbol.
	 Undefined weak syms won't yet be marked as dynamic.  */
      if (h->dynindx == -1
	  && !h->forced_local)
	{
	  if (! bfd_elf_link_record_dynamic_symbol (info, h))
	    return FALSE;
	}

      s = htab->elf.sgot;
      h->got.offset = s->size;
      dyn = htab->elf.dynamic_sections_created;
      if (tls_type & (GOT_TLS_GD | GOT_TLS_IE))
	{
	  /* TLS_GD needs two dynamic relocs and two GOT slots.  */
	  if (tls_type & GOT_TLS_GD)
	    {
	      s->size += 2 * RISCV_ELF_WORD_BYTES;
	      htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela);
	    }

	  /* TLS_IE needs one dynamic reloc and one GOT slot.  */
	  if (tls_type & GOT_TLS_IE)
	    {
	      s->size += RISCV_ELF_WORD_BYTES;
	      htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
	    }
	}
      else
	{
	  s->size += RISCV_ELF_WORD_BYTES;
	  if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, bfd_link_pic (info), h)
	      && ! UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
	    htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
	}
    }
  else
    h->got.offset = (bfd_vma) -1;

  eh = (struct riscv_elf_link_hash_entry *) h;
  if (eh->dyn_relocs == NULL)
    return TRUE;

  /* In the shared -Bsymbolic case, discard space allocated for
     dynamic pc-relative relocs against symbols which turn out to be
     defined in regular objects.  For the normal shared case, discard
     space for pc-relative relocs that have become local due to symbol
     visibility changes.  */

  if (bfd_link_pic (info))
    {
      if (SYMBOL_CALLS_LOCAL (info, h))
	{
	  struct elf_dyn_relocs **pp;

	  for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
	    {
	      p->count -= p->pc_count;
	      p->pc_count = 0;
	      if (p->count == 0)
		*pp = p->next;
	      else
		pp = &p->next;
	    }
	}

      /* Also discard relocs on undefined weak syms with non-default
	 visibility.  */
      if (eh->dyn_relocs != NULL
	  && h->root.type == bfd_link_hash_undefweak)
	{
	  if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
	      || UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
	    eh->dyn_relocs = NULL;

	  /* Make sure undefined weak symbols are output as a dynamic
	     symbol in PIEs.  */
	  else if (h->dynindx == -1
		   && !h->forced_local)
	    {
	      if (! bfd_elf_link_record_dynamic_symbol (info, h))
		return FALSE;
	    }
	}
    }
  else
    {
      /* For the non-shared case, discard space for relocs against
	 symbols which turn out to need copy relocs or are not
	 dynamic.  */

      if (!h->non_got_ref
	  && ((h->def_dynamic
	       && !h->def_regular)
	      || (htab->elf.dynamic_sections_created
		  && (h->root.type == bfd_link_hash_undefweak
		      || h->root.type == bfd_link_hash_undefined))))
	{
	  /* Make sure this symbol is output as a dynamic symbol.
	     Undefined weak syms won't yet be marked as dynamic.  */
	  if (h->dynindx == -1
	      && !h->forced_local)
	    {
	      if (! bfd_elf_link_record_dynamic_symbol (info, h))
		return FALSE;
	    }

	  /* If that succeeded, we know we'll be keeping all the
	     relocs.  */
	  if (h->dynindx != -1)
	    goto keep;
	}

      eh->dyn_relocs = NULL;

    keep: ;
    }

  /* Finally, allocate space.  */
  for (p = eh->dyn_relocs; p != NULL; p = p->next)
    {
      asection *sreloc = elf_section_data (p->sec)->sreloc;
      sreloc->size += p->count * sizeof (ElfNN_External_Rela);
    }

  return TRUE;
}

/* Set DF_TEXTREL if we find any dynamic relocs that apply to
   read-only sections.  */

static bfd_boolean
maybe_set_textrel (struct elf_link_hash_entry *h, void *info_p)
{
  asection *sec;

  if (h->root.type == bfd_link_hash_indirect)
    return TRUE;

  sec = readonly_dynrelocs (h);
  if (sec != NULL)
    {
      struct bfd_link_info *info = (struct bfd_link_info *) info_p;

      info->flags |= DF_TEXTREL;
      info->callbacks->minfo
	(_("%pB: dynamic relocation against `%pT' in read-only section `%pA'\n"),
	 sec->owner, h->root.root.string, sec);

      /* Not an error, just cut short the traversal.  */
      return FALSE;
    }
  return TRUE;
}

static bfd_boolean
riscv_elf_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
{
  struct riscv_elf_link_hash_table *htab;
  bfd *dynobj;
  asection *s;
  bfd *ibfd;

  htab = riscv_elf_hash_table (info);
  BFD_ASSERT (htab != NULL);
  dynobj = htab->elf.dynobj;
  BFD_ASSERT (dynobj != NULL);

  if (elf_hash_table (info)->dynamic_sections_created)
    {
      /* Set the contents of the .interp section to the interpreter.  */
      if (bfd_link_executable (info) && !info->nointerp)
	{
	  s = bfd_get_linker_section (dynobj, ".interp");
	  BFD_ASSERT (s != NULL);
	  s->size = strlen (ELFNN_DYNAMIC_INTERPRETER) + 1;
	  s->contents = (unsigned char *) ELFNN_DYNAMIC_INTERPRETER;
	}
    }

  /* Set up .got offsets for local syms, and space for local dynamic
     relocs.  */
  for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
    {
      bfd_signed_vma *local_got;
      bfd_signed_vma *end_local_got;
      char *local_tls_type;
      bfd_size_type locsymcount;
      Elf_Internal_Shdr *symtab_hdr;
      asection *srel;

      if (! is_riscv_elf (ibfd))
	continue;

      for (s = ibfd->sections; s != NULL; s = s->next)
	{
	  struct elf_dyn_relocs *p;

	  for (p = elf_section_data (s)->local_dynrel; p != NULL; p = p->next)
	    {
	      if (!bfd_is_abs_section (p->sec)
		  && bfd_is_abs_section (p->sec->output_section))
		{
		  /* Input section has been discarded, either because
		     it is a copy of a linkonce section or due to
		     linker script /DISCARD/, so we'll be discarding
		     the relocs too.  */
		}
	      else if (p->count != 0)
		{
		  srel = elf_section_data (p->sec)->sreloc;
		  srel->size += p->count * sizeof (ElfNN_External_Rela);
		  if ((p->sec->output_section->flags & SEC_READONLY) != 0)
		    info->flags |= DF_TEXTREL;
		}
	    }
	}

      local_got = elf_local_got_refcounts (ibfd);
      if (!local_got)
	continue;

      symtab_hdr = &elf_symtab_hdr (ibfd);
      locsymcount = symtab_hdr->sh_info;
      end_local_got = local_got + locsymcount;
      local_tls_type = _bfd_riscv_elf_local_got_tls_type (ibfd);
      s = htab->elf.sgot;
      srel = htab->elf.srelgot;
      for (; local_got < end_local_got; ++local_got, ++local_tls_type)
	{
	  if (*local_got > 0)
	    {
	      *local_got = s->size;
	      s->size += RISCV_ELF_WORD_BYTES;
	      if (*local_tls_type & GOT_TLS_GD)
		s->size += RISCV_ELF_WORD_BYTES;
	      if (bfd_link_pic (info)
		  || (*local_tls_type & (GOT_TLS_GD | GOT_TLS_IE)))
		srel->size += sizeof (ElfNN_External_Rela);
	    }
	  else
	    *local_got = (bfd_vma) -1;
	}
    }

  /* Allocate global sym .plt and .got entries, and space for global
     sym dynamic relocs.  */
  elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, info);

  if (htab->elf.sgotplt)
    {
      struct elf_link_hash_entry *got;
      got = elf_link_hash_lookup (elf_hash_table (info),
				  "_GLOBAL_OFFSET_TABLE_",
				  FALSE, FALSE, FALSE);

      /* Don't allocate .got.plt section if there are no GOT nor PLT
	 entries and there is no refeence to _GLOBAL_OFFSET_TABLE_.  */
      if ((got == NULL
	   || !got->ref_regular_nonweak)
	  && (htab->elf.sgotplt->size == GOTPLT_HEADER_SIZE)
	  && (htab->elf.splt == NULL
	      || htab->elf.splt->size == 0)
	  && (htab->elf.sgot == NULL
	      || (htab->elf.sgot->size
		  == get_elf_backend_data (output_bfd)->got_header_size)))
	htab->elf.sgotplt->size = 0;
    }

  /* The check_relocs and adjust_dynamic_symbol entry points have
     determined the sizes of the various dynamic sections.  Allocate
     memory for them.  */
  for (s = dynobj->sections; s != NULL; s = s->next)
    {
      if ((s->flags & SEC_LINKER_CREATED) == 0)
	continue;

      if (s == htab->elf.splt
	  || s == htab->elf.sgot
	  || s == htab->elf.sgotplt
	  || s == htab->elf.sdynbss
	  || s == htab->elf.sdynrelro
	  || s == htab->sdyntdata)
	{
	  /* Strip this section if we don't need it; see the
	     comment below.  */
	}
      else if (strncmp (s->name, ".rela", 5) == 0)
	{
	  if (s->size != 0)
	    {
	      /* We use the reloc_count field as a counter if we need
		 to copy relocs into the output file.  */
	      s->reloc_count = 0;
	    }
	}
      else
	{
	  /* It's not one of our sections.  */
	  continue;
	}

      if (s->size == 0)
	{
	  /* If we don't need this section, strip it from the
	     output file.  This is mostly to handle .rela.bss and
	     .rela.plt.  We must create both sections in
	     create_dynamic_sections, because they must be created
	     before the linker maps input sections to output
	     sections.  The linker does that before
	     adjust_dynamic_symbol is called, and it is that
	     function which decides whether anything needs to go
	     into these sections.  */
	  s->flags |= SEC_EXCLUDE;
	  continue;
	}

      if ((s->flags & SEC_HAS_CONTENTS) == 0)
	continue;

      /* Allocate memory for the section contents.  Zero the memory
	 for the benefit of .rela.plt, which has 4 unused entries
	 at the beginning, and we don't want garbage.  */
      s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size);
      if (s->contents == NULL)
	return FALSE;
    }

  if (elf_hash_table (info)->dynamic_sections_created)
    {
      /* Add some entries to the .dynamic section.  We fill in the
	 values later, in riscv_elf_finish_dynamic_sections, but we
	 must add the entries now so that we get the correct size for
	 the .dynamic section.  The DT_DEBUG entry is filled in by the
	 dynamic linker and used by the debugger.  */
#define add_dynamic_entry(TAG, VAL) \
  _bfd_elf_add_dynamic_entry (info, TAG, VAL)

      if (bfd_link_executable (info))
	{
	  if (!add_dynamic_entry (DT_DEBUG, 0))
	    return FALSE;
	}

      if (htab->elf.srelplt->size != 0)
	{
	  if (!add_dynamic_entry (DT_PLTGOT, 0)
	      || !add_dynamic_entry (DT_PLTRELSZ, 0)
	      || !add_dynamic_entry (DT_PLTREL, DT_RELA)
	      || !add_dynamic_entry (DT_JMPREL, 0))
	    return FALSE;
	}

      if (!add_dynamic_entry (DT_RELA, 0)
	  || !add_dynamic_entry (DT_RELASZ, 0)
	  || !add_dynamic_entry (DT_RELAENT, sizeof (ElfNN_External_Rela)))
	return FALSE;

      /* If any dynamic relocs apply to a read-only section,
	 then we need a DT_TEXTREL entry.  */
      if ((info->flags & DF_TEXTREL) == 0)
	elf_link_hash_traverse (&htab->elf, maybe_set_textrel, info);

      if (info->flags & DF_TEXTREL)
	{
	  if (!add_dynamic_entry (DT_TEXTREL, 0))
	    return FALSE;
	}
    }
#undef add_dynamic_entry

  return TRUE;
}

#define TP_OFFSET 0
#define DTP_OFFSET 0x800

/* Return the relocation value for a TLS dtp-relative reloc.  */

static bfd_vma
dtpoff (struct bfd_link_info *info, bfd_vma address)
{
  /* If tls_sec is NULL, we should have signalled an error already.  */
  if (elf_hash_table (info)->tls_sec == NULL)
    return 0;
  return address - elf_hash_table (info)->tls_sec->vma - DTP_OFFSET;
}

/* Return the relocation value for a static TLS tp-relative relocation.  */

static bfd_vma
tpoff (struct bfd_link_info *info, bfd_vma address)
{
  /* If tls_sec is NULL, we should have signalled an error already.  */
  if (elf_hash_table (info)->tls_sec == NULL)
    return 0;
  return address - elf_hash_table (info)->tls_sec->vma - TP_OFFSET;
}

/* Return the global pointer's value, or 0 if it is not in use.  */

static bfd_vma
riscv_global_pointer_value (struct bfd_link_info *info)
{
  struct bfd_link_hash_entry *h;

  h = bfd_link_hash_lookup (info->hash, RISCV_GP_SYMBOL, FALSE, FALSE, TRUE);
  if (h == NULL || h->type != bfd_link_hash_defined)
    return 0;

  return h->u.def.value + sec_addr (h->u.def.section);
}

/* Emplace a static relocation.  */

static bfd_reloc_status_type
perform_relocation (const reloc_howto_type *howto,
		    const Elf_Internal_Rela *rel,
		    bfd_vma value,
		    asection *input_section,
		    bfd *input_bfd,
		    bfd_byte *contents)
{
  if (howto->pc_relative)
    value -= sec_addr (input_section) + rel->r_offset;
  value += rel->r_addend;

  switch (ELFNN_R_TYPE (rel->r_info))
    {
    case R_RISCV_HI20:
    case R_RISCV_TPREL_HI20:
    case R_RISCV_PCREL_HI20:
    case R_RISCV_GOT_HI20:
    case R_RISCV_TLS_GOT_HI20:
    case R_RISCV_TLS_GD_HI20:
      if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)))
	return bfd_reloc_overflow;
      value = ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value));
      break;

    case R_RISCV_LO12_I:
    case R_RISCV_GPREL_I:
    case R_RISCV_TPREL_LO12_I:
    case R_RISCV_TPREL_I:
    case R_RISCV_PCREL_LO12_I:
      value = ENCODE_ITYPE_IMM (value);
      break;

    case R_RISCV_LO12_S:
    case R_RISCV_GPREL_S:
    case R_RISCV_TPREL_LO12_S:
    case R_RISCV_TPREL_S:
    case R_RISCV_PCREL_LO12_S:
      value = ENCODE_STYPE_IMM (value);
      break;

    case R_RISCV_CALL:
    case R_RISCV_CALL_PLT:
      if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)))
	return bfd_reloc_overflow;
      value = ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value))
	      | (ENCODE_ITYPE_IMM (value) << 32);
      break;

    case R_RISCV_JAL:
      if (!VALID_UJTYPE_IMM (value))
	return bfd_reloc_overflow;
      value = ENCODE_UJTYPE_IMM (value);
      break;

    case R_RISCV_BRANCH:
      if (!VALID_SBTYPE_IMM (value))
	return bfd_reloc_overflow;
      value = ENCODE_SBTYPE_IMM (value);
      break;

    case R_RISCV_RVC_BRANCH:
      if (!VALID_RVC_B_IMM (value))
	return bfd_reloc_overflow;
      value = ENCODE_RVC_B_IMM (value);
      break;

    case R_RISCV_RVC_JUMP:
      if (!VALID_RVC_J_IMM (value))
	return bfd_reloc_overflow;
      value = ENCODE_RVC_J_IMM (value);
      break;

    case R_RISCV_RVC_LUI:
      if (RISCV_CONST_HIGH_PART (value) == 0)
	{
	  /* Linker relaxation can convert an address equal to or greater than
	     0x800 to slightly below 0x800.  C.LUI does not accept zero as a
	     valid immediate.  We can fix this by converting it to a C.LI.  */
	  bfd_vma insn = bfd_get (howto->bitsize, input_bfd,
				  contents + rel->r_offset);
	  insn = (insn & ~MATCH_C_LUI) | MATCH_C_LI;
	  bfd_put (howto->bitsize, input_bfd, insn, contents + rel->r_offset);
	  value = ENCODE_RVC_IMM (0);
	}
      else if (!VALID_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (value)))
	return bfd_reloc_overflow;
      else
	value = ENCODE_RVC_LUI_IMM (RISCV_CONST_HIGH_PART (value));
      break;

    case R_RISCV_32:
    case R_RISCV_64:
    case R_RISCV_ADD8:
    case R_RISCV_ADD16:
    case R_RISCV_ADD32:
    case R_RISCV_ADD64:
    case R_RISCV_SUB6:
    case R_RISCV_SUB8:
    case R_RISCV_SUB16:
    case R_RISCV_SUB32:
    case R_RISCV_SUB64:
    case R_RISCV_SET6:
    case R_RISCV_SET8:
    case R_RISCV_SET16:
    case R_RISCV_SET32:
    case R_RISCV_32_PCREL:
    case R_RISCV_TLS_DTPREL32:
    case R_RISCV_TLS_DTPREL64:
      break;

    case R_RISCV_DELETE:
      return bfd_reloc_ok;

    default:
      return bfd_reloc_notsupported;
    }

  bfd_vma word = bfd_get (howto->bitsize, input_bfd, contents + rel->r_offset);
  word = (word & ~howto->dst_mask) | (value & howto->dst_mask);
  bfd_put (howto->bitsize, input_bfd, word, contents + rel->r_offset);

  return bfd_reloc_ok;
}

/* Remember all PC-relative high-part relocs we've encountered to help us
   later resolve the corresponding low-part relocs.  */

typedef struct
{
  bfd_vma address;
  bfd_vma value;
} riscv_pcrel_hi_reloc;

typedef struct riscv_pcrel_lo_reloc
{
  asection *			 input_section;
  struct bfd_link_info *	 info;
  reloc_howto_type *		 howto;
  const Elf_Internal_Rela *	 reloc;
  bfd_vma			 addr;
  const char *			 name;
  bfd_byte *			 contents;
  struct riscv_pcrel_lo_reloc *	 next;
} riscv_pcrel_lo_reloc;

typedef struct
{
  htab_t hi_relocs;
  riscv_pcrel_lo_reloc *lo_relocs;
} riscv_pcrel_relocs;

static hashval_t
riscv_pcrel_reloc_hash (const void *entry)
{
  const riscv_pcrel_hi_reloc *e = entry;
  return (hashval_t)(e->address >> 2);
}

static bfd_boolean
riscv_pcrel_reloc_eq (const void *entry1, const void *entry2)
{
  const riscv_pcrel_hi_reloc *e1 = entry1, *e2 = entry2;
  return e1->address == e2->address;
}

static bfd_boolean
riscv_init_pcrel_relocs (riscv_pcrel_relocs *p)
{

  p->lo_relocs = NULL;
  p->hi_relocs = htab_create (1024, riscv_pcrel_reloc_hash,
			      riscv_pcrel_reloc_eq, free);
  return p->hi_relocs != NULL;
}

static void
riscv_free_pcrel_relocs (riscv_pcrel_relocs *p)
{
  riscv_pcrel_lo_reloc *cur = p->lo_relocs;

  while (cur != NULL)
    {
      riscv_pcrel_lo_reloc *next = cur->next;
      free (cur);
      cur = next;
    }

  htab_delete (p->hi_relocs);
}

static bfd_boolean
riscv_zero_pcrel_hi_reloc (Elf_Internal_Rela *rel,
			   struct bfd_link_info *info,
			   bfd_vma pc,
			   bfd_vma addr,
			   bfd_byte *contents,
			   const reloc_howto_type *howto,
			   bfd *input_bfd)
{
  /* We may need to reference low addreses in PC-relative modes even when the
   * PC is far away from these addresses.  For example, undefweak references
   * need to produce the address 0 when linked.  As 0 is far from the arbitrary
   * addresses that we can link PC-relative programs at, the linker can't
   * actually relocate references to those symbols.  In order to allow these
   * programs to work we simply convert the PC-relative auipc sequences to
   * 0-relative lui sequences.  */
  if (bfd_link_pic (info))
    return FALSE;

  /* If it's possible to reference the symbol using auipc we do so, as that's
   * more in the spirit of the PC-relative relocations we're processing.  */
  bfd_vma offset = addr - pc;
  if (ARCH_SIZE == 32 || VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (offset)))
    return FALSE;

  /* If it's impossible to reference this with a LUI-based offset then don't
   * bother to convert it at all so users still see the PC-relative relocation
   * in the truncation message.  */
  if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (addr)))
    return FALSE;

  rel->r_info = ELFNN_R_INFO(addr, R_RISCV_HI20);

  bfd_vma insn = bfd_get(howto->bitsize, input_bfd, contents + rel->r_offset);
  insn = (insn & ~MASK_AUIPC) | MATCH_LUI;
  bfd_put(howto->bitsize, input_bfd, insn, contents + rel->r_offset);
  return TRUE;
}

static bfd_boolean
riscv_record_pcrel_hi_reloc (riscv_pcrel_relocs *p, bfd_vma addr,
			     bfd_vma value, bfd_boolean absolute)
{
  bfd_vma offset = absolute ? value : value - addr;
  riscv_pcrel_hi_reloc entry = {addr, offset};
  riscv_pcrel_hi_reloc **slot =
    (riscv_pcrel_hi_reloc **) htab_find_slot (p->hi_relocs, &entry, INSERT);

  BFD_ASSERT (*slot == NULL);
  *slot = (riscv_pcrel_hi_reloc *) bfd_malloc (sizeof (riscv_pcrel_hi_reloc));
  if (*slot == NULL)
    return FALSE;
  **slot = entry;
  return TRUE;
}

static bfd_boolean
riscv_record_pcrel_lo_reloc (riscv_pcrel_relocs *p,
			     asection *input_section,
			     struct bfd_link_info *info,
			     reloc_howto_type *howto,
			     const Elf_Internal_Rela *reloc,
			     bfd_vma addr,
			     const char *name,
			     bfd_byte *contents)
{
  riscv_pcrel_lo_reloc *entry;
  entry = (riscv_pcrel_lo_reloc *) bfd_malloc (sizeof (riscv_pcrel_lo_reloc));
  if (entry == NULL)
    return FALSE;
  *entry = (riscv_pcrel_lo_reloc) {input_section, info, howto, reloc, addr,
				   name, contents, p->lo_relocs};
  p->lo_relocs = entry;
  return TRUE;
}

static bfd_boolean
riscv_resolve_pcrel_lo_relocs (riscv_pcrel_relocs *p)
{
  riscv_pcrel_lo_reloc *r;

  for (r = p->lo_relocs; r != NULL; r = r->next)
    {
      bfd *input_bfd = r->input_section->owner;

      riscv_pcrel_hi_reloc search = {r->addr, 0};
      riscv_pcrel_hi_reloc *entry = htab_find (p->hi_relocs, &search);
      if (entry == NULL
	  /* Check for overflow into bit 11 when adding reloc addend.  */
	  || (! (entry->value & 0x800)
	      && ((entry->value + r->reloc->r_addend) & 0x800)))
	{
	  char *string = (entry == NULL
			  ? "%pcrel_lo missing matching %pcrel_hi"
			  : "%pcrel_lo overflow with an addend");
	  (*r->info->callbacks->reloc_dangerous)
	    (r->info, string, input_bfd, r->input_section, r->reloc->r_offset);
	  return TRUE;
	}

      perform_relocation (r->howto, r->reloc, entry->value, r->input_section,
			  input_bfd, r->contents);
    }

  return TRUE;
}

/* Relocate a RISC-V ELF section.

   The RELOCATE_SECTION function is called by the new ELF backend linker
   to handle the relocations for a section.

   The relocs are always passed as Rela structures.

   This function is responsible for adjusting the section contents as
   necessary, and (if generating a relocatable output file) adjusting
   the reloc addend as necessary.

   This function does not have to worry about setting the reloc
   address or the reloc symbol index.

   LOCAL_SYMS is a pointer to the swapped in local symbols.

   LOCAL_SECTIONS is an array giving the section in the input file
   corresponding to the st_shndx field of each local symbol.

   The global hash table entry for the global symbols can be found
   via elf_sym_hashes (input_bfd).

   When generating relocatable output, this function must handle
   STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
   going to be the section symbol corresponding to the output
   section, which means that the addend must be adjusted
   accordingly.  */

static bfd_boolean
riscv_elf_relocate_section (bfd *output_bfd,
			    struct bfd_link_info *info,
			    bfd *input_bfd,
			    asection *input_section,
			    bfd_byte *contents,
			    Elf_Internal_Rela *relocs,
			    Elf_Internal_Sym *local_syms,
			    asection **local_sections)
{
  Elf_Internal_Rela *rel;
  Elf_Internal_Rela *relend;
  riscv_pcrel_relocs pcrel_relocs;
  bfd_boolean ret = FALSE;
  asection *sreloc = elf_section_data (input_section)->sreloc;
  struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
  Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (input_bfd);
  struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (input_bfd);
  bfd_vma *local_got_offsets = elf_local_got_offsets (input_bfd);
  bfd_boolean absolute;

  if (!riscv_init_pcrel_relocs (&pcrel_relocs))
    return FALSE;

  relend = relocs + input_section->reloc_count;
  for (rel = relocs; rel < relend; rel++)
    {
      unsigned long r_symndx;
      struct elf_link_hash_entry *h;
      Elf_Internal_Sym *sym;
      asection *sec;
      bfd_vma relocation;
      bfd_reloc_status_type r = bfd_reloc_ok;
      const char *name;
      bfd_vma off, ie_off;
      bfd_boolean unresolved_reloc, is_ie = FALSE;
      bfd_vma pc = sec_addr (input_section) + rel->r_offset;
      int r_type = ELFNN_R_TYPE (rel->r_info), tls_type;
      reloc_howto_type *howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
      const char *msg = NULL;
      char *msg_buf = NULL;
      bfd_boolean resolved_to_zero;

      if (howto == NULL
	  || r_type == R_RISCV_GNU_VTINHERIT || r_type == R_RISCV_GNU_VTENTRY)
	continue;

      /* This is a final link.  */
      r_symndx = ELFNN_R_SYM (rel->r_info);
      h = NULL;
      sym = NULL;
      sec = NULL;
      unresolved_reloc = FALSE;
      if (r_symndx < symtab_hdr->sh_info)
	{
	  sym = local_syms + r_symndx;
	  sec = local_sections[r_symndx];
	  relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
	}
      else
	{
	  bfd_boolean warned, ignored;

	  RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
				   r_symndx, symtab_hdr, sym_hashes,
				   h, sec, relocation,
				   unresolved_reloc, warned, ignored);
	  if (warned)
	    {
	      /* To avoid generating warning messages about truncated
		 relocations, set the relocation's address to be the same as
		 the start of this section.  */
	      if (input_section->output_section != NULL)
		relocation = input_section->output_section->vma;
	      else
		relocation = 0;
	    }
	}

      if (sec != NULL && discarded_section (sec))
	RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
					 rel, 1, relend, howto, 0, contents);

      if (bfd_link_relocatable (info))
	continue;

      if (h != NULL)
	name = h->root.root.string;
      else
	{
	  name = (bfd_elf_string_from_elf_section
		  (input_bfd, symtab_hdr->sh_link, sym->st_name));
	  if (name == NULL || *name == '\0')
	    name = bfd_section_name (sec);
	}

      resolved_to_zero = (h != NULL
			  && UNDEFWEAK_NO_DYNAMIC_RELOC (info, h));

      switch (r_type)
	{
	case R_RISCV_NONE:
	case R_RISCV_RELAX:
	case R_RISCV_TPREL_ADD:
	case R_RISCV_COPY:
	case R_RISCV_JUMP_SLOT:
	case R_RISCV_RELATIVE:
	  /* These require nothing of us at all.  */
	  continue;

	case R_RISCV_HI20:
	case R_RISCV_BRANCH:
	case R_RISCV_RVC_BRANCH:
	case R_RISCV_RVC_LUI:
	case R_RISCV_LO12_I:
	case R_RISCV_LO12_S:
	case R_RISCV_SET6:
	case R_RISCV_SET8:
	case R_RISCV_SET16:
	case R_RISCV_SET32:
	case R_RISCV_32_PCREL:
	case R_RISCV_DELETE:
	  /* These require no special handling beyond perform_relocation.  */
	  break;

	case R_RISCV_GOT_HI20:
	  if (h != NULL)
	    {
	      bfd_boolean dyn, pic;

	      off = h->got.offset;
	      BFD_ASSERT (off != (bfd_vma) -1);
	      dyn = elf_hash_table (info)->dynamic_sections_created;
	      pic = bfd_link_pic (info);

	      if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, pic, h)
		  || (pic && SYMBOL_REFERENCES_LOCAL (info, h)))
		{
		  /* This is actually a static link, or it is a
		     -Bsymbolic link and the symbol is defined
		     locally, or the symbol was forced to be local
		     because of a version file.  We must initialize
		     this entry in the global offset table.  Since the
		     offset must always be a multiple of the word size,
		     we use the least significant bit to record whether
		     we have initialized it already.

		     When doing a dynamic link, we create a .rela.got
		     relocation entry to initialize the value.  This
		     is done in the finish_dynamic_symbol routine.  */
		  if ((off & 1) != 0)
		    off &= ~1;
		  else
		    {
		      bfd_put_NN (output_bfd, relocation,
				  htab->elf.sgot->contents + off);
		      h->got.offset |= 1;
		    }
		}
	      else
		unresolved_reloc = FALSE;
	    }
	  else
	    {
	      BFD_ASSERT (local_got_offsets != NULL
			  && local_got_offsets[r_symndx] != (bfd_vma) -1);

	      off = local_got_offsets[r_symndx];

	      /* The offset must always be a multiple of the word size.
		 So, we can use the least significant bit to record
		 whether we have already processed this entry.  */
	      if ((off & 1) != 0)
		off &= ~1;
	      else
		{
		  if (bfd_link_pic (info))
		    {
		      asection *s;
		      Elf_Internal_Rela outrel;

		      /* We need to generate a R_RISCV_RELATIVE reloc
			 for the dynamic linker.  */
		      s = htab->elf.srelgot;
		      BFD_ASSERT (s != NULL);

		      outrel.r_offset = sec_addr (htab->elf.sgot) + off;
		      outrel.r_info =
			ELFNN_R_INFO (0, R_RISCV_RELATIVE);
		      outrel.r_addend = relocation;
		      relocation = 0;
		      riscv_elf_append_rela (output_bfd, s, &outrel);
		    }

		  bfd_put_NN (output_bfd, relocation,
			      htab->elf.sgot->contents + off);
		  local_got_offsets[r_symndx] |= 1;
		}
	    }
	  relocation = sec_addr (htab->elf.sgot) + off;
	  absolute = riscv_zero_pcrel_hi_reloc (rel,
						info,
						pc,
						relocation,
						contents,
						howto,
						input_bfd);
	  r_type = ELFNN_R_TYPE (rel->r_info);
	  howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
	  if (howto == NULL)
	    r = bfd_reloc_notsupported;
	  else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
						 relocation, absolute))
	    r = bfd_reloc_overflow;
	  break;

	case R_RISCV_ADD8:
	case R_RISCV_ADD16:
	case R_RISCV_ADD32:
	case R_RISCV_ADD64:
	  {
	    bfd_vma old_value = bfd_get (howto->bitsize, input_bfd,
					 contents + rel->r_offset);
	    relocation = old_value + relocation;
	  }
	  break;

	case R_RISCV_SUB6:
	case R_RISCV_SUB8:
	case R_RISCV_SUB16:
	case R_RISCV_SUB32:
	case R_RISCV_SUB64:
	  {
	    bfd_vma old_value = bfd_get (howto->bitsize, input_bfd,
					 contents + rel->r_offset);
	    relocation = old_value - relocation;
	  }
	  break;

	case R_RISCV_CALL:
	  /* Handle a call to an undefined weak function.  This won't be
	     relaxed, so we have to handle it here.  */
	  if (h != NULL && h->root.type == bfd_link_hash_undefweak
	      && h->plt.offset == MINUS_ONE)
	    {
	      /* We can use x0 as the base register.  */
	      bfd_vma insn = bfd_get_32 (input_bfd,
					 contents + rel->r_offset + 4);
	      insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
	      bfd_put_32 (input_bfd, insn, contents + rel->r_offset + 4);
	      /* Set the relocation value so that we get 0 after the pc
		 relative adjustment.  */
	      relocation = sec_addr (input_section) + rel->r_offset;
	    }
	  /* Fall through.  */

	case R_RISCV_CALL_PLT:
	case R_RISCV_JAL:
	case R_RISCV_RVC_JUMP:
	  if (bfd_link_pic (info) && h != NULL && h->plt.offset != MINUS_ONE)
	    {
	      /* Refer to the PLT entry.  */
	      relocation = sec_addr (htab->elf.splt) + h->plt.offset;
	      unresolved_reloc = FALSE;
	    }
	  break;

	case R_RISCV_TPREL_HI20:
	  relocation = tpoff (info, relocation);
	  break;

	case R_RISCV_TPREL_LO12_I:
	case R_RISCV_TPREL_LO12_S:
	  relocation = tpoff (info, relocation);
	  break;

	case R_RISCV_TPREL_I:
	case R_RISCV_TPREL_S:
	  relocation = tpoff (info, relocation);
	  if (VALID_ITYPE_IMM (relocation + rel->r_addend))
	    {
	      /* We can use tp as the base register.  */
	      bfd_vma insn = bfd_get_32 (input_bfd, contents + rel->r_offset);
	      insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
	      insn |= X_TP << OP_SH_RS1;
	      bfd_put_32 (input_bfd, insn, contents + rel->r_offset);
	    }
	  else
	    r = bfd_reloc_overflow;
	  break;

	case R_RISCV_GPREL_I:
	case R_RISCV_GPREL_S:
	  {
	    bfd_vma gp = riscv_global_pointer_value (info);
	    bfd_boolean x0_base = VALID_ITYPE_IMM (relocation + rel->r_addend);
	    if (x0_base || VALID_ITYPE_IMM (relocation + rel->r_addend - gp))
	      {
		/* We can use x0 or gp as the base register.  */
		bfd_vma insn = bfd_get_32 (input_bfd, contents + rel->r_offset);
		insn &= ~(OP_MASK_RS1 << OP_SH_RS1);
		if (!x0_base)
		  {
		    rel->r_addend -= gp;
		    insn |= X_GP << OP_SH_RS1;
		  }
		bfd_put_32 (input_bfd, insn, contents + rel->r_offset);
	      }
	    else
	      r = bfd_reloc_overflow;
	    break;
	  }

	case R_RISCV_PCREL_HI20:
	  absolute = riscv_zero_pcrel_hi_reloc (rel,
						info,
						pc,
						relocation,
						contents,
						howto,
						input_bfd);
	  r_type = ELFNN_R_TYPE (rel->r_info);
	  howto = riscv_elf_rtype_to_howto (input_bfd, r_type);
	  if (howto == NULL)
	    r = bfd_reloc_notsupported;
	  else if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
						 relocation + rel->r_addend,
						 absolute))
	    r = bfd_reloc_overflow;
	  break;

	case R_RISCV_PCREL_LO12_I:
	case R_RISCV_PCREL_LO12_S:
	  /* We don't allow section symbols plus addends as the auipc address,
	     because then riscv_relax_delete_bytes would have to search through
	     all relocs to update these addends.  This is also ambiguous, as
	     we do allow offsets to be added to the target address, which are
	     not to be used to find the auipc address.  */
	  if (((sym != NULL && (ELF_ST_TYPE (sym->st_info) == STT_SECTION))
	       || (h != NULL && h->type == STT_SECTION))
	      && rel->r_addend)
	    {
	      msg = _("%pcrel_lo section symbol with an addend");
	      r = bfd_reloc_dangerous;
	      break;
	    }

	  if (riscv_record_pcrel_lo_reloc (&pcrel_relocs, input_section, info,
					   howto, rel, relocation, name,
					   contents))
	    continue;
	  r = bfd_reloc_overflow;
	  break;

	case R_RISCV_TLS_DTPREL32:
	case R_RISCV_TLS_DTPREL64:
	  relocation = dtpoff (info, relocation);
	  break;

	case R_RISCV_32:
	case R_RISCV_64:
	  if ((input_section->flags & SEC_ALLOC) == 0)
	    break;

	  if ((bfd_link_pic (info)
	       && (h == NULL
		   || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
		       && !resolved_to_zero)
		   || h->root.type != bfd_link_hash_undefweak)
	       && (! howto->pc_relative
		   || !SYMBOL_CALLS_LOCAL (info, h)))
	      || (!bfd_link_pic (info)
		  && h != NULL
		  && h->dynindx != -1
		  && !h->non_got_ref
		  && ((h->def_dynamic
		       && !h->def_regular)
		      || h->root.type == bfd_link_hash_undefweak
		      || h->root.type == bfd_link_hash_undefined)))
	    {
	      Elf_Internal_Rela outrel;
	      bfd_boolean skip_static_relocation, skip_dynamic_relocation;

	      /* When generating a shared object, these relocations
		 are copied into the output file to be resolved at run
		 time.  */

	      outrel.r_offset =
		_bfd_elf_section_offset (output_bfd, info, input_section,
					 rel->r_offset);
	      skip_static_relocation = outrel.r_offset != (bfd_vma) -2;
	      skip_dynamic_relocation = outrel.r_offset >= (bfd_vma) -2;
	      outrel.r_offset += sec_addr (input_section);

	      if (skip_dynamic_relocation)
		memset (&outrel, 0, sizeof outrel);
	      else if (h != NULL && h->dynindx != -1
		       && !(bfd_link_pic (info)
			    && SYMBOLIC_BIND (info, h)
			    && h->def_regular))
		{
		  outrel.r_info = ELFNN_R_INFO (h->dynindx, r_type);
		  outrel.r_addend = rel->r_addend;
		}
	      else
		{
		  outrel.r_info = ELFNN_R_INFO (0, R_RISCV_RELATIVE);
		  outrel.r_addend = relocation + rel->r_addend;
		}

	      riscv_elf_append_rela (output_bfd, sreloc, &outrel);
	      if (skip_static_relocation)
		continue;
	    }
	  break;

	case R_RISCV_TLS_GOT_HI20:
	  is_ie = TRUE;
	  /* Fall through.  */

	case R_RISCV_TLS_GD_HI20:
	  if (h != NULL)
	    {
	      off = h->got.offset;
	      h->got.offset |= 1;
	    }
	  else
	    {
	      off = local_got_offsets[r_symndx];
	      local_got_offsets[r_symndx] |= 1;
	    }

	  tls_type = _bfd_riscv_elf_tls_type (input_bfd, h, r_symndx);
	  BFD_ASSERT (tls_type & (GOT_TLS_IE | GOT_TLS_GD));
	  /* If this symbol is referenced by both GD and IE TLS, the IE
	     reference's GOT slot follows the GD reference's slots.  */
	  ie_off = 0;
	  if ((tls_type & GOT_TLS_GD) && (tls_type & GOT_TLS_IE))
	    ie_off = 2 * GOT_ENTRY_SIZE;

	  if ((off & 1) != 0)
	    off &= ~1;
	  else
	    {
	      Elf_Internal_Rela outrel;
	      int indx = 0;
	      bfd_boolean need_relocs = FALSE;

	      if (htab->elf.srelgot == NULL)
		abort ();

	      if (h != NULL)
		{
		  bfd_boolean dyn, pic;
		  dyn = htab->elf.dynamic_sections_created;
		  pic = bfd_link_pic (info);

		  if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, pic, h)
		      && (!pic || !SYMBOL_REFERENCES_LOCAL (info, h)))
		    indx = h->dynindx;
		}

	      /* The GOT entries have not been initialized yet.  Do it
		 now, and emit any relocations.  */
	      if ((bfd_link_pic (info) || indx != 0)
		  && (h == NULL
		      || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
		      || h->root.type != bfd_link_hash_undefweak))
		    need_relocs = TRUE;

	      if (tls_type & GOT_TLS_GD)
		{
		  if (need_relocs)
		    {
		      outrel.r_offset = sec_addr (htab->elf.sgot) + off;
		      outrel.r_addend = 0;
		      outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPMODNN);
		      bfd_put_NN (output_bfd, 0,
				  htab->elf.sgot->contents + off);
		      riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
		      if (indx == 0)
			{
			  BFD_ASSERT (! unresolved_reloc);
			  bfd_put_NN (output_bfd,
				      dtpoff (info, relocation),
				      (htab->elf.sgot->contents + off +
				       RISCV_ELF_WORD_BYTES));
			}
		      else
			{
			  bfd_put_NN (output_bfd, 0,
				      (htab->elf.sgot->contents + off +
				       RISCV_ELF_WORD_BYTES));
			  outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_DTPRELNN);
			  outrel.r_offset += RISCV_ELF_WORD_BYTES;
			  riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
			}
		    }
		  else
		    {
		      /* If we are not emitting relocations for a
			 general dynamic reference, then we must be in a
			 static link or an executable link with the
			 symbol binding locally.  Mark it as belonging
			 to module 1, the executable.  */
		      bfd_put_NN (output_bfd, 1,
				  htab->elf.sgot->contents + off);
		      bfd_put_NN (output_bfd,
				  dtpoff (info, relocation),
				  (htab->elf.sgot->contents + off +
				   RISCV_ELF_WORD_BYTES));
		   }
		}

	      if (tls_type & GOT_TLS_IE)
		{
		  if (need_relocs)
		    {
		      bfd_put_NN (output_bfd, 0,
				  htab->elf.sgot->contents + off + ie_off);
		      outrel.r_offset = sec_addr (htab->elf.sgot)
				       + off + ie_off;
		      outrel.r_addend = 0;
		      if (indx == 0)
			outrel.r_addend = tpoff (info, relocation);
		      outrel.r_info = ELFNN_R_INFO (indx, R_RISCV_TLS_TPRELNN);
		      riscv_elf_append_rela (output_bfd, htab->elf.srelgot, &outrel);
		    }
		  else
		    {
		      bfd_put_NN (output_bfd, tpoff (info, relocation),
				  htab->elf.sgot->contents + off + ie_off);
		    }
		}
	    }

	  BFD_ASSERT (off < (bfd_vma) -2);
	  relocation = sec_addr (htab->elf.sgot) + off + (is_ie ? ie_off : 0);
	  if (!riscv_record_pcrel_hi_reloc (&pcrel_relocs, pc,
					    relocation, FALSE))
	    r = bfd_reloc_overflow;
	  unresolved_reloc = FALSE;
	  break;

	default:
	  r = bfd_reloc_notsupported;
	}

      /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
	 because such sections are not SEC_ALLOC and thus ld.so will
	 not process them.  */
      if (unresolved_reloc
	  && !((input_section->flags & SEC_DEBUGGING) != 0
	       && h->def_dynamic)
	  && _bfd_elf_section_offset (output_bfd, info, input_section,
				      rel->r_offset) != (bfd_vma) -1)
	{
	  switch (r_type)
	    {
	    case R_RISCV_CALL:
	    case R_RISCV_JAL:
	    case R_RISCV_RVC_JUMP:
	      if (asprintf (&msg_buf,
			    _("%%X%%P: relocation %s against `%s' can "
			      "not be used when making a shared object; "
			      "recompile with -fPIC\n"),
			    howto->name,
			    h->root.root.string) == -1)
		msg_buf = NULL;
	      break;

	    default:
	      if (asprintf (&msg_buf,
			    _("%%X%%P: unresolvable %s relocation against "
			      "symbol `%s'\n"),
			    howto->name,
			    h->root.root.string) == -1)
		msg_buf = NULL;
	      break;
	    }

	  msg = msg_buf;
	  r = bfd_reloc_notsupported;
	}

      if (r == bfd_reloc_ok)
	r = perform_relocation (howto, rel, relocation, input_section,
				input_bfd, contents);

      /* We should have already detected the error and set message before.
	 If the error message isn't set since the linker runs out of memory
	 or we don't set it before, then we should set the default message
	 with the "internal error" string here.  */
      switch (r)
	{
	case bfd_reloc_ok:
	  continue;

	case bfd_reloc_overflow:
	  info->callbacks->reloc_overflow
	    (info, (h ? &h->root : NULL), name, howto->name,
	     (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
	  break;

	case bfd_reloc_undefined:
	  info->callbacks->undefined_symbol
	    (info, name, input_bfd, input_section, rel->r_offset,
	     TRUE);
	  break;

	case bfd_reloc_outofrange:
	  if (msg == NULL)
	    msg = _("%X%P: internal error: out of range error\n");
	  break;

	case bfd_reloc_notsupported:
	  if (msg == NULL)
	    msg = _("%X%P: internal error: unsupported relocation error\n");
	  break;

	case bfd_reloc_dangerous:
	  /* The error message should already be set.  */
	  if (msg == NULL)
	    msg = _("dangerous relocation error");
	  info->callbacks->reloc_dangerous
	    (info, msg, input_bfd, input_section, rel->r_offset);
	  break;

	default:
	  msg = _("%X%P: internal error: unknown error\n");
	  break;
	}

      /* Do not report error message for the dangerous relocation again.  */
      if (msg && r != bfd_reloc_dangerous)
	info->callbacks->einfo (msg);

      /* Free the unused `msg_buf` if needed.  */
      if (msg_buf)
	free (msg_buf);

      /* We already reported the error via a callback, so don't try to report
	 it again by returning false.  That leads to spurious errors.  */
      ret = TRUE;
      goto out;
    }

  ret = riscv_resolve_pcrel_lo_relocs (&pcrel_relocs);
out:
  riscv_free_pcrel_relocs (&pcrel_relocs);
  return ret;
}

/* Finish up dynamic symbol handling.  We set the contents of various
   dynamic sections here.  */

static bfd_boolean
riscv_elf_finish_dynamic_symbol (bfd *output_bfd,
				 struct bfd_link_info *info,
				 struct elf_link_hash_entry *h,
				 Elf_Internal_Sym *sym)
{
  struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
  const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);

  if (h->plt.offset != (bfd_vma) -1)
    {
      /* We've decided to create a PLT entry for this symbol.  */
      bfd_byte *loc;
      bfd_vma i, header_address, plt_idx, got_address;
      uint32_t plt_entry[PLT_ENTRY_INSNS];
      Elf_Internal_Rela rela;

      BFD_ASSERT (h->dynindx != -1);

      /* Calculate the address of the PLT header.  */
      header_address = sec_addr (htab->elf.splt);

      /* Calculate the index of the entry.  */
      plt_idx = (h->plt.offset - PLT_HEADER_SIZE) / PLT_ENTRY_SIZE;

      /* Calculate the address of the .got.plt entry.  */
      got_address = riscv_elf_got_plt_val (plt_idx, info);

      /* Find out where the .plt entry should go.  */
      loc = htab->elf.splt->contents + h->plt.offset;

      /* Fill in the PLT entry itself.  */
      if (! riscv_make_plt_entry (output_bfd, got_address,
				  header_address + h->plt.offset,
				  plt_entry))
	return FALSE;

      for (i = 0; i < PLT_ENTRY_INSNS; i++)
	bfd_put_32 (output_bfd, plt_entry[i], loc + 4*i);

      /* Fill in the initial value of the .got.plt entry.  */
      loc = htab->elf.sgotplt->contents
	    + (got_address - sec_addr (htab->elf.sgotplt));
      bfd_put_NN (output_bfd, sec_addr (htab->elf.splt), loc);

      /* Fill in the entry in the .rela.plt section.  */
      rela.r_offset = got_address;
      rela.r_addend = 0;
      rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_JUMP_SLOT);

      loc = htab->elf.srelplt->contents + plt_idx * sizeof (ElfNN_External_Rela);
      bed->s->swap_reloca_out (output_bfd, &rela, loc);

      if (!h->def_regular)
	{
	  /* Mark the symbol as undefined, rather than as defined in
	     the .plt section.  Leave the value alone.  */
	  sym->st_shndx = SHN_UNDEF;
	  /* If the symbol is weak, we do need to clear the value.
	     Otherwise, the PLT entry would provide a definition for
	     the symbol even if the symbol wasn't defined anywhere,
	     and so the symbol would never be NULL.  */
	  if (!h->ref_regular_nonweak)
	    sym->st_value = 0;
	}
    }

  if (h->got.offset != (bfd_vma) -1
      && !(riscv_elf_hash_entry (h)->tls_type & (GOT_TLS_GD | GOT_TLS_IE))
      && !UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
    {
      asection *sgot;
      asection *srela;
      Elf_Internal_Rela rela;

      /* This symbol has an entry in the GOT.  Set it up.  */

      sgot = htab->elf.sgot;
      srela = htab->elf.srelgot;
      BFD_ASSERT (sgot != NULL && srela != NULL);

      rela.r_offset = sec_addr (sgot) + (h->got.offset &~ (bfd_vma) 1);

      /* If this is a local symbol reference, we just want to emit a RELATIVE
	 reloc.  This can happen if it is a -Bsymbolic link, or a pie link, or
	 the symbol was forced to be local because of a version file.
	 The entry in the global offset table will already have been
	 initialized in the relocate_section function.  */
      if (bfd_link_pic (info)
	  && SYMBOL_REFERENCES_LOCAL (info, h))
	{
	  BFD_ASSERT((h->got.offset & 1) != 0);
	  asection *sec = h->root.u.def.section;
	  rela.r_info = ELFNN_R_INFO (0, R_RISCV_RELATIVE);
	  rela.r_addend = (h->root.u.def.value
			   + sec->output_section->vma
			   + sec->output_offset);
	}
      else
	{
	  BFD_ASSERT((h->got.offset & 1) == 0);
	  BFD_ASSERT (h->dynindx != -1);
	  rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_NN);
	  rela.r_addend = 0;
	}

      bfd_put_NN (output_bfd, 0,
		  sgot->contents + (h->got.offset & ~(bfd_vma) 1));
      riscv_elf_append_rela (output_bfd, srela, &rela);
    }

  if (h->needs_copy)
    {
      Elf_Internal_Rela rela;
      asection *s;

      /* This symbols needs a copy reloc.  Set it up.  */
      BFD_ASSERT (h->dynindx != -1);

      rela.r_offset = sec_addr (h->root.u.def.section) + h->root.u.def.value;
      rela.r_info = ELFNN_R_INFO (h->dynindx, R_RISCV_COPY);
      rela.r_addend = 0;
      if (h->root.u.def.section == htab->elf.sdynrelro)
	s = htab->elf.sreldynrelro;
      else
	s = htab->elf.srelbss;
      riscv_elf_append_rela (output_bfd, s, &rela);
    }

  /* Mark some specially defined symbols as absolute.  */
  if (h == htab->elf.hdynamic
      || (h == htab->elf.hgot || h == htab->elf.hplt))
    sym->st_shndx = SHN_ABS;

  return TRUE;
}

/* Finish up the dynamic sections.  */

static bfd_boolean
riscv_finish_dyn (bfd *output_bfd, struct bfd_link_info *info,
		  bfd *dynobj, asection *sdyn)
{
  struct riscv_elf_link_hash_table *htab = riscv_elf_hash_table (info);
  const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
  size_t dynsize = bed->s->sizeof_dyn;
  bfd_byte *dyncon, *dynconend;

  dynconend = sdyn->contents + sdyn->size;
  for (dyncon = sdyn->contents; dyncon < dynconend; dyncon += dynsize)
    {
      Elf_Internal_Dyn dyn;
      asection *s;

      bed->s->swap_dyn_in (dynobj, dyncon, &dyn);

      switch (dyn.d_tag)
	{
	case DT_PLTGOT:
	  s = htab->elf.sgotplt;
	  dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
	  break;
	case DT_JMPREL:
	  s = htab->elf.srelplt;
	  dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
	  break;
	case DT_PLTRELSZ:
	  s = htab->elf.srelplt;
	  dyn.d_un.d_val = s->size;
	  break;
	default:
	  continue;
	}

      bed->s->swap_dyn_out (output_bfd, &dyn, dyncon);
    }
  return TRUE;
}

static bfd_boolean
riscv_elf_finish_dynamic_sections (bfd *output_bfd,
				   struct bfd_link_info *info)
{
  bfd *dynobj;
  asection *sdyn;
  struct riscv_elf_link_hash_table *htab;

  htab = riscv_elf_hash_table (info);
  BFD_ASSERT (htab != NULL);
  dynobj = htab->elf.dynobj;

  sdyn = bfd_get_linker_section (dynobj, ".dynamic");

  if (elf_hash_table (info)->dynamic_sections_created)
    {
      asection *splt;
      bfd_boolean ret;

      splt = htab->elf.splt;
      BFD_ASSERT (splt != NULL && sdyn != NULL);

      ret = riscv_finish_dyn (output_bfd, info, dynobj, sdyn);

      if (!ret)
	return ret;

      /* Fill in the head and tail entries in the procedure linkage table.  */
      if (splt->size > 0)
	{
	  int i;
	  uint32_t plt_header[PLT_HEADER_INSNS];
	  ret = riscv_make_plt_header (output_bfd,
				       sec_addr (htab->elf.sgotplt),
				       sec_addr (splt), plt_header);
	  if (!ret)
	    return ret;

	  for (i = 0; i < PLT_HEADER_INSNS; i++)
	    bfd_put_32 (output_bfd, plt_header[i], splt->contents + 4*i);

	  elf_section_data (splt->output_section)->this_hdr.sh_entsize
	    = PLT_ENTRY_SIZE;
	}
    }

  if (htab->elf.sgotplt)
    {
      asection *output_section = htab->elf.sgotplt->output_section;

      if (bfd_is_abs_section (output_section))
	{
	  (*_bfd_error_handler)
	    (_("discarded output section: `%pA'"), htab->elf.sgotplt);
	  return FALSE;
	}

      if (htab->elf.sgotplt->size > 0)
	{
	  /* Write the first two entries in .got.plt, needed for the dynamic
	     linker.  */
	  bfd_put_NN (output_bfd, (bfd_vma) -1, htab->elf.sgotplt->contents);
	  bfd_put_NN (output_bfd, (bfd_vma) 0,
		      htab->elf.sgotplt->contents + GOT_ENTRY_SIZE);
	}

      elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE;
    }

  if (htab->elf.sgot)
    {
      asection *output_section = htab->elf.sgot->output_section;

      if (htab->elf.sgot->size > 0)
	{
	  /* Set the first entry in the global offset table to the address of
	     the dynamic section.  */
	  bfd_vma val = sdyn ? sec_addr (sdyn) : 0;
	  bfd_put_NN (output_bfd, val, htab->elf.sgot->contents);
	}

      elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE;
    }

  return TRUE;
}

/* Return address for Ith PLT stub in section PLT, for relocation REL
   or (bfd_vma) -1 if it should not be included.  */

static bfd_vma
riscv_elf_plt_sym_val (bfd_vma i, const asection *plt,
		       const arelent *rel ATTRIBUTE_UNUSED)
{
  return plt->vma + PLT_HEADER_SIZE + i * PLT_ENTRY_SIZE;
}

static enum elf_reloc_type_class
riscv_reloc_type_class (const struct bfd_link_info *info ATTRIBUTE_UNUSED,
			const asection *rel_sec ATTRIBUTE_UNUSED,
			const Elf_Internal_Rela *rela)
{
  switch (ELFNN_R_TYPE (rela->r_info))
    {
    case R_RISCV_RELATIVE:
      return reloc_class_relative;
    case R_RISCV_JUMP_SLOT:
      return reloc_class_plt;
    case R_RISCV_COPY:
      return reloc_class_copy;
    default:
      return reloc_class_normal;
    }
}

/* Given the ELF header flags in FLAGS, it returns a string that describes the
   float ABI.  */

static const char *
riscv_float_abi_string (flagword flags)
{
  switch (flags & EF_RISCV_FLOAT_ABI)
    {
    case EF_RISCV_FLOAT_ABI_SOFT:
      return "soft-float";
      break;
    case EF_RISCV_FLOAT_ABI_SINGLE:
      return "single-float";
      break;
    case EF_RISCV_FLOAT_ABI_DOUBLE:
      return "double-float";
      break;
    case EF_RISCV_FLOAT_ABI_QUAD:
      return "quad-float";
      break;
    default:
      abort ();
    }
}

/* The information of architecture attribute.  */
static riscv_subset_list_t in_subsets;
static riscv_subset_list_t out_subsets;
static riscv_subset_list_t merged_subsets;

/* Predicator for standard extension.  */

static bfd_boolean
riscv_std_ext_p (const char *name)
{
  return (strlen (name) == 1) && (name[0] != 'x') && (name[0] != 's');
}

/* Predicator for non-standard extension.  */

static bfd_boolean
riscv_non_std_ext_p (const char *name)
{
  return (strlen (name) >= 2) && (name[0] == 'x');
}

/* Predicator for standard supervisor extension.  */

static bfd_boolean
riscv_std_sv_ext_p (const char *name)
{
  return (strlen (name) >= 2) && (name[0] == 's') && (name[1] != 'x');
}

/* Predicator for non-standard supervisor extension.  */

static bfd_boolean
riscv_non_std_sv_ext_p (const char *name)
{
  return (strlen (name) >= 3) && (name[0] == 's') && (name[1] == 'x');
}

/* Error handler when version mis-match.  */

static void
riscv_version_mismatch (bfd *ibfd,
			struct riscv_subset_t *in,
			struct riscv_subset_t *out)
{
  _bfd_error_handler
    (_("error: %pB: Mis-matched ISA version for '%s' extension. "
       "%d.%d vs %d.%d"),
       ibfd, in->name,
       in->major_version, in->minor_version,
       out->major_version, out->minor_version);
}

/* Return true if subset is 'i' or 'e'.  */

static bfd_boolean
riscv_i_or_e_p (bfd *ibfd,
		const char *arch,
		struct riscv_subset_t *subset)
{
  if ((strcasecmp (subset->name, "e") != 0)
      && (strcasecmp (subset->name, "i") != 0))
    {
      _bfd_error_handler
	(_("error: %pB: corrupted ISA string '%s'. "
	   "First letter should be 'i' or 'e' but got '%s'."),
	   ibfd, arch, subset->name);
      return FALSE;
    }
  return TRUE;
}

/* Merge standard extensions.

   Return Value:
     Return FALSE if failed to merge.

   Arguments:
     `bfd`: bfd handler.
     `in_arch`: Raw arch string for input object.
     `out_arch`: Raw arch string for output object.
     `pin`: subset list for input object, and it'll skip all merged subset after
            merge.
     `pout`: Like `pin`, but for output object.  */

static bfd_boolean
riscv_merge_std_ext (bfd *ibfd,
		     const char *in_arch,
		     const char *out_arch,
		     struct riscv_subset_t **pin,
		     struct riscv_subset_t **pout)
{
  const char *standard_exts = riscv_supported_std_ext ();
  const char *p;
  struct riscv_subset_t *in = *pin;
  struct riscv_subset_t *out = *pout;

  /* First letter should be 'i' or 'e'.  */
  if (!riscv_i_or_e_p (ibfd, in_arch, in))
    return FALSE;

  if (!riscv_i_or_e_p (ibfd, out_arch, out))
    return FALSE;

  if (in->name[0] != out->name[0])
    {
      /* TODO: We might allow merge 'i' with 'e'.  */
      _bfd_error_handler
	(_("error: %pB: Mis-matched ISA string to merge '%s' and '%s'."),
	 ibfd, in->name, out->name);
      return FALSE;
    }
  else if ((in->major_version != out->major_version) ||
	   (in->minor_version != out->minor_version))
    {
      /* TODO: Allow different merge policy.  */
      riscv_version_mismatch (ibfd, in, out);
      return FALSE;
    }
  else
    riscv_add_subset (&merged_subsets,
		      in->name, in->major_version, in->minor_version);

  in = in->next;
  out = out->next;

  /* Handle standard extension first.  */
  for (p = standard_exts; *p; ++p)
    {
      char find_ext[2] = {*p, '\0'};
      struct riscv_subset_t *find_in =
	riscv_lookup_subset (&in_subsets, find_ext);
      struct riscv_subset_t *find_out =
	riscv_lookup_subset (&out_subsets, find_ext);

      if (find_in == NULL && find_out == NULL)
	continue;

      /* Check version is same or not.  */
      /* TODO: Allow different merge policy.  */
      if ((find_in != NULL && find_out != NULL)
	  && ((find_in->major_version != find_out->major_version)
	      || (find_in->minor_version != find_out->minor_version)))
	{
	  riscv_version_mismatch (ibfd, in, out);
	  return FALSE;
	}

      struct riscv_subset_t *merged = find_in ? find_in : find_out;
      riscv_add_subset (&merged_subsets, merged->name,
			merged->major_version, merged->minor_version);
    }

  /* Skip all standard extensions.  */
  while ((in != NULL) && riscv_std_ext_p (in->name)) in = in->next;
  while ((out != NULL) && riscv_std_ext_p (out->name)) out = out->next;

  *pin = in;
  *pout = out;

  return TRUE;
}

/* Merge non-standard and supervisor extensions.
   Return Value:
     Return FALSE if failed to merge.

   Arguments:
     `bfd`: bfd handler.
     `in_arch`: Raw arch string for input object.
     `out_arch`: Raw arch string for output object.
     `pin`: subset list for input object, and it'll skip all merged subset after
            merge.
     `pout`: Like `pin`, but for output object. */

static bfd_boolean
riscv_merge_non_std_and_sv_ext (bfd *ibfd,
				riscv_subset_t **pin,
				riscv_subset_t **pout,
				bfd_boolean (*predicate_func) (const char *))
{
  riscv_subset_t *in = *pin;
  riscv_subset_t *out = *pout;

  for (in = *pin; in != NULL && predicate_func (in->name); in = in->next)
    riscv_add_subset (&merged_subsets, in->name, in->major_version,
		      in->minor_version);

  for (out = *pout; out != NULL && predicate_func (out->name); out = out->next)
    {
      riscv_subset_t *find_ext =
	riscv_lookup_subset (&merged_subsets, out->name);
      if (find_ext != NULL)
	{
	  /* Check version is same or not. */
	  /* TODO: Allow different merge policy.  */
	  if ((find_ext->major_version != out->major_version)
	      || (find_ext->minor_version != out->minor_version))
	    {
	      riscv_version_mismatch (ibfd, find_ext, out);
	      return FALSE;
	    }
	}
      else
	riscv_add_subset (&merged_subsets, out->name,
			  out->major_version, out->minor_version);
    }

  *pin = in;
  *pout = out;
  return TRUE;
}

/* Merge Tag_RISCV_arch attribute.  */

static char *
riscv_merge_arch_attr_info (bfd *ibfd, char *in_arch, char *out_arch)
{
  riscv_subset_t *in, *out;
  char *merged_arch_str;

  unsigned xlen_in, xlen_out;
  merged_subsets.head = NULL;
  merged_subsets.tail = NULL;

  riscv_parse_subset_t rpe_in;
  riscv_parse_subset_t rpe_out;

  rpe_in.subset_list = &in_subsets;
  rpe_in.error_handler = _bfd_error_handler;
  rpe_in.xlen = &xlen_in;

  rpe_out.subset_list = &out_subsets;
  rpe_out.error_handler = _bfd_error_handler;
  rpe_out.xlen = &xlen_out;

  if (in_arch == NULL && out_arch == NULL)
    return NULL;

  if (in_arch == NULL && out_arch != NULL)
    return out_arch;

  if (in_arch != NULL && out_arch == NULL)
    return in_arch;

  /* Parse subset from arch string.  */
  if (!riscv_parse_subset (&rpe_in, in_arch))
    return NULL;

  if (!riscv_parse_subset (&rpe_out, out_arch))
    return NULL;

  /* Checking XLEN.  */
  if (xlen_out != xlen_in)
    {
      _bfd_error_handler
	(_("error: %pB: ISA string of input (%s) doesn't match "
	   "output (%s)."), ibfd, in_arch, out_arch);
      return NULL;
    }

  /* Merge subset list.  */
  in = in_subsets.head;
  out = out_subsets.head;

  /* Merge standard extension.  */
  if (!riscv_merge_std_ext (ibfd, in_arch, out_arch, &in, &out))
    return NULL;
  /* Merge non-standard extension.  */
  if (!riscv_merge_non_std_and_sv_ext (ibfd, &in, &out, riscv_non_std_ext_p))
    return NULL;
  /* Merge standard supervisor extension.  */
  if (!riscv_merge_non_std_and_sv_ext (ibfd, &in, &out, riscv_std_sv_ext_p))
    return NULL;
  /* Merge non-standard supervisor extension.  */
  if (!riscv_merge_non_std_and_sv_ext (ibfd, &in, &out, riscv_non_std_sv_ext_p))
    return NULL;

  if (xlen_in != xlen_out)
    {
      _bfd_error_handler
	(_("error: %pB: XLEN of input (%u) doesn't match "
	   "output (%u)."), ibfd, xlen_in, xlen_out);
      return NULL;
    }

  if (xlen_in != ARCH_SIZE)
    {
      _bfd_error_handler
	(_("error: %pB: Unsupported XLEN (%u), you might be "
	   "using wrong emulation."), ibfd, xlen_in);
      return NULL;
    }

  merged_arch_str = riscv_arch_str (ARCH_SIZE, &merged_subsets);

  /* Release the subset lists.  */
  riscv_release_subset_list (&in_subsets);
  riscv_release_subset_list (&out_subsets);
  riscv_release_subset_list (&merged_subsets);

  return merged_arch_str;
}

/* Merge object attributes from IBFD into output_bfd of INFO.
   Raise an error if there are conflicting attributes.  */

static bfd_boolean
riscv_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
{
  bfd *obfd = info->output_bfd;
  obj_attribute *in_attr;
  obj_attribute *out_attr;
  bfd_boolean result = TRUE;
  const char *sec_name = get_elf_backend_data (ibfd)->obj_attrs_section;
  unsigned int i;

  /* Skip linker created files.  */
  if (ibfd->flags & BFD_LINKER_CREATED)
    return TRUE;

  /* Skip any input that doesn't have an attribute section.
     This enables to link object files without attribute section with
     any others.  */
  if (bfd_get_section_by_name (ibfd, sec_name) == NULL)
    return TRUE;

  if (!elf_known_obj_attributes_proc (obfd)[0].i)
    {
      /* This is the first object.  Copy the attributes.  */
      _bfd_elf_copy_obj_attributes (ibfd, obfd);

      out_attr = elf_known_obj_attributes_proc (obfd);

      /* Use the Tag_null value to indicate the attributes have been
	 initialized.  */
      out_attr[0].i = 1;

      return TRUE;
    }

  in_attr = elf_known_obj_attributes_proc (ibfd);
  out_attr = elf_known_obj_attributes_proc (obfd);

  for (i = LEAST_KNOWN_OBJ_ATTRIBUTE; i < NUM_KNOWN_OBJ_ATTRIBUTES; i++)
    {
    switch (i)
      {
      case Tag_RISCV_arch:
	if (!out_attr[Tag_RISCV_arch].s)
	  out_attr[Tag_RISCV_arch].s = in_attr[Tag_RISCV_arch].s;
	else if (in_attr[Tag_RISCV_arch].s
		 && out_attr[Tag_RISCV_arch].s)
	  {
	    /* Check arch compatible.  */
	    char *merged_arch =
		riscv_merge_arch_attr_info (ibfd,
					    in_attr[Tag_RISCV_arch].s,
					    out_attr[Tag_RISCV_arch].s);
	    if (merged_arch == NULL)
	      {
		result = FALSE;
		out_attr[Tag_RISCV_arch].s = "";
	      }
	    else
	      out_attr[Tag_RISCV_arch].s = merged_arch;
	  }
	break;
      case Tag_RISCV_priv_spec:
      case Tag_RISCV_priv_spec_minor:
      case Tag_RISCV_priv_spec_revision:
	if (out_attr[i].i != in_attr[i].i)
	  {
	    _bfd_error_handler
	      (_("error: %pB: conflicting priv spec version "
		 "(major/minor/revision)."), ibfd);
	    result = FALSE;
	  }
	break;
      case Tag_RISCV_unaligned_access:
	out_attr[i].i |= in_attr[i].i;
	break;
      case Tag_RISCV_stack_align