/gas:
[deliverable/binutils-gdb.git] / bfd / elf.c
index 71e16f7518d0773ea00d867084dc6bf05d8eb79e..44af469e1ff9c1aa471a7770bbb34c574a16d1af 100644 (file)
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -1,7 +1,8 @@
 /* ELF executable support for BFD.
 
    Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
-   2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+   2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   Free Software Foundation, Inc.
 
    This file is part of BFD, the Binary File Descriptor library.
 
@@ -258,7 +259,7 @@ bfd_elf_mkcorefile (bfd *abfd)
   return bfd_elf_make_generic_object (abfd);
 }
 
-char *
+static char *
 bfd_elf_get_str_section (bfd *abfd, unsigned int shindex)
 {
   Elf_Internal_Shdr **i_shdrp;
@@ -358,6 +359,7 @@ bfd_elf_get_elf_syms (bfd *ibfd,
   const bfd_byte *esym;
   Elf_External_Sym_Shndx *alloc_extshndx;
   Elf_External_Sym_Shndx *shndx;
+  Elf_Internal_Sym *alloc_intsym;
   Elf_Internal_Sym *isym;
   Elf_Internal_Sym *isymend;
   const struct elf_backend_data *bed;
@@ -379,6 +381,7 @@ bfd_elf_get_elf_syms (bfd *ibfd,
   /* Read the symbols.  */
   alloc_ext = NULL;
   alloc_extshndx = NULL;
+  alloc_intsym = NULL;
   bed = get_elf_backend_data (ibfd);
   extsym_size = bed->s->sizeof_sym;
   amt = symcount * extsym_size;
@@ -419,7 +422,8 @@ bfd_elf_get_elf_syms (bfd *ibfd,
 
   if (intsym_buf == NULL)
     {
-      intsym_buf = bfd_malloc2 (symcount, sizeof (Elf_Internal_Sym));
+      alloc_intsym = bfd_malloc2 (symcount, sizeof (Elf_Internal_Sym));
+      intsym_buf = alloc_intsym;
       if (intsym_buf == NULL)
        goto out;
     }
@@ -435,6 +439,8 @@ bfd_elf_get_elf_syms (bfd *ibfd,
        (*_bfd_error_handler) (_("%B symbol number %lu references "
                                 "nonexistent SHT_SYMTAB_SHNDX section"),
                               ibfd, (unsigned long) symoffset);
+       if (alloc_intsym != NULL)
+         free (alloc_intsym);
        intsym_buf = NULL;
        goto out;
       }
@@ -1014,45 +1020,6 @@ _bfd_elf_make_section_from_shdr (bfd *abfd,
   return TRUE;
 }
 
-/*
-INTERNAL_FUNCTION
-       bfd_elf_find_section
-
-SYNOPSIS
-       struct elf_internal_shdr *bfd_elf_find_section (bfd *abfd, char *name);
-
-DESCRIPTION
-       Helper functions for GDB to locate the string tables.
-       Since BFD hides string tables from callers, GDB needs to use an
-       internal hook to find them.  Sun's .stabstr, in particular,
-       isn't even pointed to by the .stab section, so ordinary
-       mechanisms wouldn't work to find it, even if we had some.
-*/
-
-struct elf_internal_shdr *
-bfd_elf_find_section (bfd *abfd, char *name)
-{
-  Elf_Internal_Shdr **i_shdrp;
-  char *shstrtab;
-  unsigned int max;
-  unsigned int i;
-
-  i_shdrp = elf_elfsections (abfd);
-  if (i_shdrp != NULL)
-    {
-      shstrtab = bfd_elf_get_str_section (abfd,
-                                         elf_elfheader (abfd)->e_shstrndx);
-      if (shstrtab != NULL)
-       {
-         max = elf_numsections (abfd);
-         for (i = 1; i < max; i++)
-           if (!strcmp (&shstrtab[i_shdrp[i]->sh_name], name))
-             return i_shdrp[i];
-       }
-    }
-  return 0;
-}
-
 const char *const bfd_elf_section_type_names[] = {
   "SHT_NULL", "SHT_PROGBITS", "SHT_SYMTAB", "SHT_STRTAB",
   "SHT_RELA", "SHT_HASH", "SHT_DYNAMIC", "SHT_NOTE",
@@ -1393,7 +1360,7 @@ bfd_elf_print_symbol (bfd *abfd,
     case bfd_print_symbol_more:
       fprintf (file, "elf ");
       bfd_fprintf_vma (abfd, file, symbol->value);
-      fprintf (file, " %lx", (long) symbol->flags);
+      fprintf (file, " %lx", (unsigned long) symbol->flags);
       break;
     case bfd_print_symbol_all:
       {
@@ -1603,6 +1570,8 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
 
       if (hdr->sh_entsize != bed->s->sizeof_sym)
        return FALSE;
+      if (hdr->sh_info * hdr->sh_entsize > hdr->sh_size)
+       return FALSE;
       BFD_ASSERT (elf_onesymtab (abfd) == 0);
       elf_onesymtab (abfd) = shindex;
       elf_tdata (abfd)->symtab_hdr = *hdr;
@@ -1858,14 +1827,8 @@ bfd_section_from_shdr (bfd *abfd, unsigned int shindex)
       return TRUE;
 
     case SHT_GROUP:
-      /* We need a BFD section for objcopy and relocatable linking,
-        and it's handy to have the signature available as the section
-        name.  */
       if (! IS_VALID_GROUP_SECTION_HEADER (hdr))
        return FALSE;
-      name = group_signature (abfd, hdr);
-      if (name == NULL)
-       return FALSE;
       if (!_bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
        return FALSE;
       if (hdr->contents != NULL)
@@ -2682,13 +2645,15 @@ elf_fake_sections (bfd *abfd, asection *asect, void *failedptrarg)
     *failedptr = TRUE;
 }
 
-/* Fill in the contents of a SHT_GROUP section.  */
+/* Fill in the contents of a SHT_GROUP section.  Called from
+   _bfd_elf_compute_section_file_positions for gas, objcopy, and
+   when ELF targets use the generic linker, ld.  Called for ld -r
+   from bfd_elf_final_link.  */
 
 void
 bfd_elf_set_group_contents (bfd *abfd, asection *sec, void *failedptrarg)
 {
   bfd_boolean *failedptr = failedptrarg;
-  unsigned long symindx;
   asection *elt, *first;
   unsigned char *loc;
   bfd_boolean gas;
@@ -2699,20 +2664,49 @@ bfd_elf_set_group_contents (bfd *abfd, asection *sec, void *failedptrarg)
       || *failedptr)
     return;
 
-  symindx = 0;
-  if (elf_group_id (sec) != NULL)
-    symindx = elf_group_id (sec)->udata.i;
+  if (elf_section_data (sec)->this_hdr.sh_info == 0)
+    {
+      unsigned long symindx = 0;
+
+      /* elf_group_id will have been set up by objcopy and the
+        generic linker.  */
+      if (elf_group_id (sec) != NULL)
+       symindx = elf_group_id (sec)->udata.i;
 
-  if (symindx == 0)
+      if (symindx == 0)
+       {
+         /* If called from the assembler, swap_out_syms will have set up
+            elf_section_syms.  */
+         BFD_ASSERT (elf_section_syms (abfd) != NULL);
+         symindx = elf_section_syms (abfd)[sec->index]->udata.i;
+       }
+      elf_section_data (sec)->this_hdr.sh_info = symindx;
+    }
+  else if (elf_section_data (sec)->this_hdr.sh_info == (unsigned int) -2)
     {
-      /* If called from the assembler, swap_out_syms will have set up
-        elf_section_syms;  If called for "ld -r", use target_index.  */
-      if (elf_section_syms (abfd) != NULL)
-       symindx = elf_section_syms (abfd)[sec->index]->udata.i;
-      else
-       symindx = sec->target_index;
+      /* The ELF backend linker sets sh_info to -2 when the group
+        signature symbol is global, and thus the index can't be
+        set until all local symbols are output.  */
+      asection *igroup = elf_sec_group (elf_next_in_group (sec));
+      struct bfd_elf_section_data *sec_data = elf_section_data (igroup);
+      unsigned long symndx = sec_data->this_hdr.sh_info;
+      unsigned long extsymoff = 0;
+      struct elf_link_hash_entry *h;
+
+      if (!elf_bad_symtab (igroup->owner))
+       {
+         Elf_Internal_Shdr *symtab_hdr;
+
+         symtab_hdr = &elf_tdata (igroup->owner)->symtab_hdr;
+         extsymoff = symtab_hdr->sh_info;
+       }
+      h = elf_sym_hashes (igroup->owner)[symndx - extsymoff];
+      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;
+
+      elf_section_data (sec)->this_hdr.sh_info = h->indx;
     }
-  elf_section_data (sec)->this_hdr.sh_info = symindx;
 
   /* The contents won't be allocated for "ld -r" or objcopy.  */
   gas = TRUE;
@@ -2746,14 +2740,17 @@ bfd_elf_set_group_contents (bfd *abfd, asection *sec, void *failedptrarg)
       asection *s;
       unsigned int idx;
 
-      loc -= 4;
       s = elt;
-      if (!gas)
-       s = s->output_section;
-      idx = 0;
-      if (s != NULL)
-       idx = elf_section_data (s)->this_idx;
-      H_PUT_32 (abfd, idx, loc);
+      if (! elf_discarded_section (s))
+       {
+         loc -= 4;
+         if (!gas)
+           s = s->output_section;
+         idx = 0;
+         if (s != NULL)
+           idx = elf_section_data (s)->this_idx;
+         H_PUT_32 (abfd, idx, loc);
+       }
       elt = elf_next_in_group (elt);
       if (elt == first)
        break;
@@ -3381,7 +3378,7 @@ get_program_header_size (bfd *abfd, struct bfd_link_info *info)
       ++segs;
     }
 
-  if (info->relro)
+  if (info != NULL && info->relro)
     {
       /* We need a PT_GNU_RELRO segment.  */
       ++segs;
@@ -3763,8 +3760,13 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
            }
 
          /* Allow interested parties a chance to override our decision.  */
-         if (last_hdr && info->callbacks->override_segment_assignment)
-           new_segment = info->callbacks->override_segment_assignment (info, abfd, hdr, last_hdr, new_segment);
+         if (last_hdr != NULL
+             && info != NULL
+             && info->callbacks->override_segment_assignment != NULL)
+           new_segment
+             = info->callbacks->override_segment_assignment (info, abfd, hdr,
+                                                             last_hdr,
+                                                             new_segment);
 
          if (! new_segment)
            {
@@ -3939,7 +3941,7 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
          pm = &m->next;
        }
 
-      if (info->relro)
+      if (info != NULL && info->relro)
        {
          for (m = mfirst; m != NULL; m = m->next)
            {
@@ -4121,14 +4123,19 @@ assign_file_positions_for_load_sections (bfd *abfd,
   bfd_size_type maxpagesize;
   unsigned int alloc;
   unsigned int i, j;
+  bfd_vma header_pad = 0;
 
   if (link_info == NULL
-      && !elf_modify_segment_map (abfd, link_info, FALSE))
+      && !_bfd_elf_map_sections_to_segments (abfd, link_info))
     return FALSE;
 
   alloc = 0;
   for (m = elf_tdata (abfd)->segment_map; m != NULL; m = m->next)
-    ++alloc;
+    {
+      ++alloc;
+      if (m->header_size)
+       header_pad = m->header_size;
+    }
 
   elf_elfheader (abfd)->e_phoff = bed->s->sizeof_ehdr;
   elf_elfheader (abfd)->e_phentsize = bed->s->sizeof_phdr;
@@ -4146,7 +4153,21 @@ assign_file_positions_for_load_sections (bfd *abfd,
       return TRUE;
     }
 
-  phdrs = bfd_alloc2 (abfd, alloc, sizeof (Elf_Internal_Phdr));
+  /* We're writing the size in elf_tdata (abfd)->program_header_size,
+     see assign_file_positions_except_relocs, so make sure we have
+     that amount allocated, with trailing space cleared.
+     The variable alloc contains the computed need, while elf_tdata
+     (abfd)->program_header_size contains the size used for the
+     layout.
+     See ld/emultempl/elf-generic.em:gld${EMULATION_NAME}_map_segments
+     where the layout is forced to according to a larger size in the
+     last iterations for the testcase ld-elf/header.  */
+  BFD_ASSERT (elf_tdata (abfd)->program_header_size % bed->s->sizeof_phdr
+             == 0);
+  phdrs = bfd_zalloc2 (abfd,
+                      (elf_tdata (abfd)->program_header_size
+                       / bed->s->sizeof_phdr),
+                      sizeof (Elf_Internal_Phdr));
   elf_tdata (abfd)->phdr = phdrs;
   if (phdrs == NULL)
     return FALSE;
@@ -4157,6 +4178,11 @@ assign_file_positions_for_load_sections (bfd *abfd,
 
   off = bed->s->sizeof_ehdr;
   off += alloc * bed->s->sizeof_phdr;
+  if (header_pad < (bfd_vma) off)
+    header_pad = 0;
+  else
+    header_pad -= off;
+  off += header_pad;
 
   for (m = elf_tdata (abfd)->segment_map, p = phdrs, j = 0;
        m != NULL;
@@ -4253,21 +4279,14 @@ assign_file_positions_for_load_sections (bfd *abfd,
              elf_section_type (m->sections[i]) = SHT_NOBITS;
 
          /* Find out whether this segment contains any loadable
-            sections.  If the first section isn't loadable, the same
-            holds for any other sections.  */
-         i = 0;
-         while (elf_section_type (m->sections[i]) == SHT_NOBITS)
-           {
-             /* If a segment starts with .tbss, we need to look
-                at the next section to decide whether the segment
-                has any loadable sections.  */
-             if ((elf_section_flags (m->sections[i]) & SHF_TLS) == 0
-                 || ++i >= m->count)
-               {
-                 no_contents = TRUE;
-                 break;
-               }
-           }
+            sections.  */
+         no_contents = TRUE;
+         for (i = 0; i < m->count; i++)
+           if (elf_section_type (m->sections[i]) != SHT_NOBITS)
+             {
+               no_contents = FALSE;
+               break;
+             }
 
          off_adjust = vma_page_aligned_bias (m->sections[0]->vma, off, align);
          off += off_adjust;
@@ -4351,6 +4370,11 @@ assign_file_positions_for_load_sections (bfd *abfd,
 
          p->p_filesz += alloc * bed->s->sizeof_phdr;
          p->p_memsz += alloc * bed->s->sizeof_phdr;
+         if (m->count)
+           {
+             p->p_filesz += header_pad;
+             p->p_memsz += header_pad;
+           }
        }
 
       if (p->p_type == PT_LOAD
@@ -4603,7 +4627,61 @@ assign_file_positions_for_non_load_sections (bfd *abfd,
        m != NULL;
        m = m->next, p++)
     {
-      if (m->count != 0)
+      if (p->p_type == PT_GNU_RELRO)
+       {
+         const Elf_Internal_Phdr *lp;
+
+         BFD_ASSERT (!m->includes_filehdr && !m->includes_phdrs);
+
+         if (link_info != NULL)
+           {
+             /* During linking the range of the RELRO segment is passed
+                in link_info.  */
+             for (lp = phdrs; lp < phdrs + count; ++lp)
+               {
+                 if (lp->p_type == PT_LOAD
+                     && lp->p_vaddr >= link_info->relro_start
+                     && lp->p_vaddr < link_info->relro_end
+                     && lp->p_vaddr + lp->p_filesz >= link_info->relro_end)
+                   break;
+               }
+           }
+         else
+           {
+             /* Otherwise we are copying an executable or shared
+                library, but we need to use the same linker logic.  */
+             for (lp = phdrs; lp < phdrs + count; ++lp)
+               {
+                 if (lp->p_type == PT_LOAD
+                     && lp->p_paddr == p->p_paddr)
+                   break;
+               }
+           }
+
+         if (lp < phdrs + count)
+           {
+             p->p_vaddr = lp->p_vaddr;
+             p->p_paddr = lp->p_paddr;
+             p->p_offset = lp->p_offset;
+             if (link_info != NULL)
+               p->p_filesz = link_info->relro_end - lp->p_vaddr;
+             else if (m->p_size_valid)
+               p->p_filesz = m->p_size;
+             else
+               abort ();
+             p->p_memsz = p->p_filesz;
+             p->p_align = 1;
+             p->p_flags = (lp->p_flags & ~PF_W);
+           }
+         else if (link_info != NULL)
+           {
+             memset (p, 0, sizeof *p);
+             p->p_type = PT_NULL;
+           }
+         else
+           abort ();
+       }
+      else if (m->count != 0)
        {
          if (p->p_type != PT_LOAD
              && (p->p_type != PT_NOTE
@@ -4619,87 +4697,20 @@ assign_file_positions_for_non_load_sections (bfd *abfd,
              p->p_filesz = sect->filepos - m->sections[0]->filepos;
              if (hdr->sh_type != SHT_NOBITS)
                p->p_filesz += hdr->sh_size;
-
-             if (p->p_type == PT_GNU_RELRO)
-               {
-                 /* When we get here, we are copying executable
-                    or shared library. But we need to use the same
-                    linker logic.  */
-                 Elf_Internal_Phdr *lp;
-
-                 for (lp = phdrs; lp < phdrs + count; ++lp)
-                   {
-                     if (lp->p_type == PT_LOAD
-                         && lp->p_paddr == p->p_paddr)
-                       break;
-                   }
-         
-                 if (lp < phdrs + count)
-                   {
-                     /* We should use p_size if it is valid since it
-                        may contain the first few bytes of the next
-                        SEC_ALLOC section.  */
-                     if (m->p_size_valid)
-                       p->p_filesz = m->p_size;
-                     else
-                       abort ();
-                     p->p_vaddr = lp->p_vaddr;
-                     p->p_offset = lp->p_offset;
-                     p->p_memsz = p->p_filesz;
-                     p->p_align = 1;
-                   }
-                 else
-                   abort ();
-               }
-             else
-               p->p_offset = m->sections[0]->filepos;
+             p->p_offset = m->sections[0]->filepos;
            }
        }
-      else
+      else if (m->includes_filehdr)
        {
-         if (m->includes_filehdr)
-           {
-             p->p_vaddr = filehdr_vaddr;
-             if (! m->p_paddr_valid)
-               p->p_paddr = filehdr_paddr;
-           }
-         else if (m->includes_phdrs)
-           {
-             p->p_vaddr = phdrs_vaddr;
-             if (! m->p_paddr_valid)
-               p->p_paddr = phdrs_paddr;
-           }
-         else if (p->p_type == PT_GNU_RELRO)
-           {
-             Elf_Internal_Phdr *lp;
-
-             for (lp = phdrs; lp < phdrs + count; ++lp)
-               {
-                 if (lp->p_type == PT_LOAD
-                     && lp->p_vaddr <= link_info->relro_end
-                     && lp->p_vaddr >= link_info->relro_start
-                     && (lp->p_vaddr + lp->p_filesz
-                         >= link_info->relro_end))
-                   break;
-               }
-
-             if (lp < phdrs + count
-                 && link_info->relro_end > lp->p_vaddr)
-               {
-                 p->p_vaddr = lp->p_vaddr;
-                 p->p_paddr = lp->p_paddr;
-                 p->p_offset = lp->p_offset;
-                 p->p_filesz = link_info->relro_end - lp->p_vaddr;
-                 p->p_memsz = p->p_filesz;
-                 p->p_align = 1;
-                 p->p_flags = (lp->p_flags & ~PF_W);
-               }
-             else
-               {
-                 memset (p, 0, sizeof *p);
-                 p->p_type = PT_NULL;
-               }
-           }
+         p->p_vaddr = filehdr_vaddr;
+         if (! m->p_paddr_valid)
+           p->p_paddr = filehdr_paddr;
+       }
+      else if (m->includes_phdrs)
+       {
+         p->p_vaddr = phdrs_vaddr;
+         if (! m->p_paddr_valid)
+           p->p_paddr = phdrs_paddr;
        }
     }
 
@@ -5559,19 +5570,32 @@ rewrite_elf_program_header (bfd *ibfd, bfd *obfd)
          /* Offset the segment physical address from the lma
             to allow for space taken up by elf headers.  */
          if (map->includes_filehdr)
-           map->p_paddr -= iehdr->e_ehsize;
+           {
+             if (map->p_paddr >= iehdr->e_ehsize)
+               map->p_paddr -= iehdr->e_ehsize;
+             else
+               {
+                 map->includes_filehdr = FALSE;
+                 map->includes_phdrs = FALSE;
+               }
+           }
 
          if (map->includes_phdrs)
            {
-             map->p_paddr -= iehdr->e_phnum * iehdr->e_phentsize;
-
-             /* iehdr->e_phnum is just an estimate of the number
-                of program headers that we will need.  Make a note
-                here of the number we used and the segment we chose
-                to hold these headers, so that we can adjust the
-                offset when we know the correct value.  */
-             phdr_adjust_num = iehdr->e_phnum;
-             phdr_adjust_seg = map;
+             if (map->p_paddr >= iehdr->e_phnum * iehdr->e_phentsize)
+               {
+                 map->p_paddr -= iehdr->e_phnum * iehdr->e_phentsize;
+
+                 /* iehdr->e_phnum is just an estimate of the number
+                    of program headers that we will need.  Make a note
+                    here of the number we used and the segment we chose
+                    to hold these headers, so that we can adjust the
+                    offset when we know the correct value.  */
+                 phdr_adjust_num = iehdr->e_phnum;
+                 phdr_adjust_seg = map;
+               }
+             else
+               map->includes_phdrs = FALSE;
            }
        }
 
@@ -5833,6 +5857,10 @@ copy_elf_program_header (bfd *ibfd, bfd *obfd)
            phdr_included = TRUE;
        }
 
+      if (map->includes_filehdr && first_section)
+       /* We need to keep the space used by the headers fixed.  */
+       map->header_size = first_section->vma - segment->p_vaddr;
+      
       if (!map->includes_phdrs
          && !map->includes_filehdr
          && map->p_paddr_valid)
@@ -6001,7 +6029,7 @@ _bfd_elf_init_private_section_data (bfd *ibfd,
          if (elf_section_flags (isec) & SHF_GROUP)
            elf_section_flags (osec) |= SHF_GROUP;
          elf_next_in_group (osec) = elf_next_in_group (isec);
-         elf_group_name (osec) = elf_group_name (isec);
+         elf_section_data (osec)->group = elf_section_data (isec)->group;
        }
     }
 
@@ -6397,9 +6425,8 @@ Unable to find equivalent output section for symbol '%s' from section '%s'"),
          if (type == STT_OBJECT)
            sym.st_info = ELF_ST_INFO (STB_GLOBAL, STT_COMMON);
          else
-#else
-           sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
 #endif
+           sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
        }
       else if (bfd_is_und_section (syms[idx]->section))
        sym.st_info = ELF_ST_INFO (((flags & BSF_WEAK)
@@ -7836,7 +7863,7 @@ elfcore_grok_win32pstatus (bfd *abfd, Elf_Internal_Note *note)
       /* Make a ".module/xxxxxxxx" section.  */
       /* module_info.base_address */
       base_addr = bfd_get_32 (abfd, note->descdata + 4);
-      sprintf (buf, ".module/%08lx", (long) base_addr);
+      sprintf (buf, ".module/%08lx", (unsigned long) base_addr);
 
       len = strlen (buf) + 1;
       name = bfd_alloc (abfd, len);
@@ -8796,7 +8823,7 @@ _bfd_elf_get_synthetic_symtab (bfd *abfd,
 
   relplt_name = bed->relplt_name;
   if (relplt_name == NULL)
-    relplt_name = bed->default_use_rela_p ? ".rela.plt" : ".rel.plt";
+    relplt_name = bed->rela_plts_and_copies_p ? ".rela.plt" : ".rel.plt";
   relplt = bfd_get_section_by_name (abfd, relplt_name);
   if (relplt == NULL)
     return 0;
This page took 0.033585 seconds and 4 git commands to generate.