Add experimental support for --gc-sections with COFF and PE based targets.
authorKai Tietz <ktietz@redhat.com>
Fri, 3 Jul 2015 14:50:29 +0000 (15:50 +0100)
committerNick Clifton <nickc@redhat.com>
Fri, 3 Jul 2015 14:50:29 +0000 (15:50 +0100)
PR ld/11539
bfd * coffcode.h (coff_bfd_gc_sections): Define default
to bfd_coff_gc_sections function.
* cofflink.c (init_reloc_cookie): Copy and adjust coff
related code about gc-sections from elflink.c to here.
(fini_reloc_cookie): Likewise.
(init_reloc_cookie_rels): Likewise.
(fini_reloc_cookie_rels): Likewise.
(init_reloc_cookie_for_section): Likewise.
(fini_reloc_cookie_for_section): Likewise.
(_bfd_coff_gc_mark_hook): Likewise.
(_bfd_coff_gc_mark_rsec): Likewise.
(_bfd_coff_gc_mark_reloc): Likewise.
(_bfd_coff_gc_mark): Likewise.
(_bfd_coff_gc_mark_extra_sections): Likewise.
(coff_gc_sweep_symbol_info): Likewise.
(coff_gc_sweep_symbol): Likewise.
(gc_sweep_hook_fn): Likewise.
(coff_gc_sweep): Likewise.
(bfd_coff_gc_sections): Likewise.
(_bfd_coff_gc_keep): Likewise.
* libcoff.h (coff_reloc_cookie): New struct.
(bfd_coff_gc_sections): New prototype.
(coff_gc_mark_hook_fn): New type.

ld * scripttempl/pep.sc: Mark .idata*, .CRT*, .tls*,
.rsrc*, .init, .ctor*, .dtor*, .fini, .jcr,
.eh_frame, .pdata. .xdata, and .gcc_except_table sections
as KEEP.
* scripttempl/pe.sc: Likewise.

12 files changed:
bfd/ChangeLog
bfd/coffcode.h
bfd/coffgen.c
bfd/libcoff-in.h
bfd/libcoff.h
ld/ChangeLog
ld/NEWS
ld/ld.texinfo
ld/scripttempl/pe.sc
ld/scripttempl/pep.sc
ld/testsuite/ChangeLog
ld/testsuite/lib/ld-lib.exp

index c2f404c25352aec91c96221acba3dc9d4aaeb473..8be0c91932c9f15fe0aedacf1e9c1e47c72775d5 100644 (file)
@@ -1,3 +1,32 @@
+2015-07-03   Kai Tietz  <ktietz@redhat.com>
+            Nick Clifton  <nickc@redhat.com>
+
+       PR ld/11539
+       * coffcode.h (coff_bfd_gc_sections): Define default
+       to bfd_coff_gc_sections function.
+       (coff_gc_mark_hook_fn): New type.
+       * coffgen.c (init_reloc_cookie): Copy and adjust coff
+       related code about gc-sections from elflink.c to here.
+       (fini_reloc_cookie): Likewise.
+       (init_reloc_cookie_rels): Likewise.
+       (fini_reloc_cookie_rels): Likewise.
+       (init_reloc_cookie_for_section): Likewise.
+       (fini_reloc_cookie_for_section): Likewise.
+       (_bfd_coff_gc_mark_hook): Likewise.
+       (_bfd_coff_gc_mark_rsec): Likewise.
+       (_bfd_coff_gc_mark_reloc): Likewise.
+       (_bfd_coff_gc_mark): Likewise.
+       (_bfd_coff_gc_mark_extra_sections): Likewise.
+       (coff_gc_sweep_symbol_info): Likewise.
+       (coff_gc_sweep_symbol): Likewise.
+       (gc_sweep_hook_fn): Likewise.
+       (coff_gc_sweep): Likewise.
+       (bfd_coff_gc_sections): Likewise.
+       (_bfd_coff_gc_keep): Likewise.
+       * libcoff-in.h (coff_reloc_cookie): New struct.
+       (bfd_coff_gc_sections): New prototype.
+       * libcoff.h: Regenerate.
+
 2015-07-01  Sandra Loosemore  <sandra@codesourcery.com>
            Cesar Philippidis  <cesar@codesourcery.com>
 
index 8576c0ad3e04c0a8901c869266561346c3a382ee..62a410546ae070779cb78e8f188d8ca29bed9a2e 100644 (file)
@@ -1352,6 +1352,10 @@ CODE_FRAGMENT
 .  COFF_SYMBOL_PE_SECTION
 .};
 .
+.typedef asection * (*coff_gc_mark_hook_fn)
+.  (asection *, struct bfd_link_info *, struct internal_reloc *,
+.   struct coff_link_hash_entry *, struct internal_syment *);
+.
 Special entry points for gdb to swap in coff symbol table parts:
 .typedef struct
 .{
@@ -5993,7 +5997,7 @@ static bfd_coff_backend_data bigobj_swap_table =
 #endif
 
 #ifndef coff_bfd_gc_sections
-#define coff_bfd_gc_sections               bfd_generic_gc_sections
+#define coff_bfd_gc_sections               bfd_coff_gc_sections
 #endif
 
 #ifndef coff_bfd_lookup_section_flags
index 2cd7b09c6a21774872d9f25c984f2d60e20904ac..481e4a5c91f690c9b3b26a20b4c6467319cd1af1 100644 (file)
@@ -2626,3 +2626,431 @@ _bfd_coff_section_already_linked (bfd *abfd,
     info->callbacks->einfo (_("%F%P: already_linked_table: %E\n"));
   return FALSE;
 }
+
+/* Initialize COOKIE for input bfd ABFD. */
+
+static bfd_boolean
+init_reloc_cookie (struct coff_reloc_cookie *cookie,
+                  struct bfd_link_info *info ATTRIBUTE_UNUSED,
+                  bfd *abfd)
+{
+  /* Sometimes the symbol table does not yet have been loaded here.  */
+  bfd_coff_slurp_symbol_table (abfd);
+
+  cookie->abfd = abfd;
+  cookie->sym_hashes = obj_coff_sym_hashes (abfd);
+
+  cookie->symbols = obj_symbols (abfd);
+
+  return TRUE;
+}
+
+/* Free the memory allocated by init_reloc_cookie, if appropriate.  */
+
+static void
+fini_reloc_cookie (struct coff_reloc_cookie *cookie ATTRIBUTE_UNUSED,
+                  bfd *abfd ATTRIBUTE_UNUSED)
+{
+  /* Nothing to do.  */
+}
+
+/* Initialize the relocation information in COOKIE for input section SEC
+   of input bfd ABFD.  */
+
+static bfd_boolean
+init_reloc_cookie_rels (struct coff_reloc_cookie *cookie,
+                       struct bfd_link_info *info ATTRIBUTE_UNUSED,
+                       bfd *abfd,
+                       asection *sec)
+{
+  if (sec->reloc_count == 0)
+    {
+      cookie->rels = NULL;
+      cookie->relend = NULL;
+      cookie->rel = NULL;
+      return TRUE;
+    }
+
+  cookie->rels = _bfd_coff_read_internal_relocs (abfd, sec, FALSE, NULL, 0, NULL);
+
+  if (cookie->rels == NULL)
+    return FALSE;
+
+  cookie->rel = cookie->rels;
+  cookie->relend = (cookie->rels + sec->reloc_count);
+  return TRUE;
+}
+
+/* Free the memory allocated by init_reloc_cookie_rels,
+   if appropriate.  */
+
+static void
+fini_reloc_cookie_rels (struct coff_reloc_cookie *cookie,
+                       asection *sec)
+{
+  if (cookie->rels && coff_section_data (NULL, sec)->relocs != cookie->rels)
+    free (cookie->rels);
+}
+
+/* Initialize the whole of COOKIE for input section SEC.  */
+
+static bfd_boolean
+init_reloc_cookie_for_section (struct coff_reloc_cookie *cookie,
+                              struct bfd_link_info *info,
+                              asection *sec)
+{
+  if (!init_reloc_cookie (cookie, info, sec->owner))
+    return FALSE;
+
+  if (!init_reloc_cookie_rels (cookie, info, sec->owner, sec))
+    {
+      fini_reloc_cookie (cookie, sec->owner);
+      return FALSE;
+    }
+  return TRUE;
+}
+
+/* Free the memory allocated by init_reloc_cookie_for_section,
+   if appropriate.  */
+
+static void
+fini_reloc_cookie_for_section (struct coff_reloc_cookie *cookie,
+                              asection *sec)
+{
+  fini_reloc_cookie_rels (cookie, sec);
+  fini_reloc_cookie (cookie, sec->owner);
+}
+
+static asection *
+_bfd_coff_gc_mark_hook (asection *sec,
+                       struct bfd_link_info *info ATTRIBUTE_UNUSED,
+                       struct internal_reloc *rel ATTRIBUTE_UNUSED,
+                       struct coff_link_hash_entry *h,
+                       struct internal_syment *sym)
+{
+  if (h != NULL)
+    {
+      switch (h->root.type)
+        {
+        case bfd_link_hash_defined:
+        case bfd_link_hash_defweak:
+          return h->root.u.def.section;
+
+        case bfd_link_hash_common:
+          return h->root.u.c.p->section;
+
+       case bfd_link_hash_undefined:
+       case bfd_link_hash_undefweak:
+        default:
+          break;
+        }
+      return NULL;
+    }
+
+  return coff_section_from_bfd_index (sec->owner, sym->n_scnum);
+}
+
+/* COOKIE->rel describes a relocation against section SEC, which is
+   a section we've decided to keep.  Return the section that contains
+   the relocation symbol, or NULL if no section contains it.  */
+
+static asection *
+_bfd_coff_gc_mark_rsec (struct bfd_link_info *info, asection *sec,
+                       coff_gc_mark_hook_fn gc_mark_hook,
+                       struct coff_reloc_cookie *cookie)
+{
+  struct coff_link_hash_entry *h;
+
+  h = cookie->sym_hashes[cookie->rel->r_symndx];
+  if (h != NULL)
+    {
+      while (h->root.type == bfd_link_hash_indirect
+            || h->root.type == bfd_link_hash_warning)
+       h = (struct coff_link_hash_entry *) h->root.u.i.link;
+
+      return (*gc_mark_hook) (sec, info, cookie->rel, h, NULL);
+    }
+
+  return (*gc_mark_hook) (sec, info, cookie->rel, NULL,
+                         &(cookie->symbols
+                           + obj_convert (sec->owner)[cookie->rel->r_symndx])->native->u.syment);
+}
+
+static bfd_boolean _bfd_coff_gc_mark
+  (struct bfd_link_info *, asection *, coff_gc_mark_hook_fn);
+
+/* COOKIE->rel describes a relocation against section SEC, which is
+   a section we've decided to keep.  Mark the section that contains
+   the relocation symbol.  */
+
+static bfd_boolean
+_bfd_coff_gc_mark_reloc (struct bfd_link_info *info,
+                        asection *sec,
+                        coff_gc_mark_hook_fn gc_mark_hook,
+                        struct coff_reloc_cookie *cookie)
+{
+  asection *rsec;
+
+  rsec = _bfd_coff_gc_mark_rsec (info, sec, gc_mark_hook, cookie);
+  if (rsec && !rsec->gc_mark)
+    {
+      if (bfd_get_flavour (rsec->owner) != bfd_target_coff_flavour)
+       rsec->gc_mark = 1;
+      else if (!_bfd_coff_gc_mark (info, rsec, gc_mark_hook))
+       return FALSE;
+    }
+  return TRUE;
+}
+
+/* The mark phase of garbage collection.  For a given section, mark
+   it and any sections in this section's group, and all the sections
+   which define symbols to which it refers.  */
+
+static bfd_boolean
+_bfd_coff_gc_mark (struct bfd_link_info *info,
+                  asection *sec,
+                  coff_gc_mark_hook_fn gc_mark_hook)
+{
+  bfd_boolean ret = TRUE;
+
+  sec->gc_mark = 1;
+
+  /* Look through the section relocs.  */
+  if ((sec->flags & SEC_RELOC) != 0
+      && sec->reloc_count > 0)
+    {
+      struct coff_reloc_cookie cookie;
+
+      if (!init_reloc_cookie_for_section (&cookie, info, sec))
+        ret = FALSE;
+      else
+        {
+          for (; cookie.rel < cookie.relend; cookie.rel++)
+            {
+             if (!_bfd_coff_gc_mark_reloc (info, sec, gc_mark_hook, &cookie))
+               {
+                 ret = FALSE;
+                 break;
+               }
+           }
+          fini_reloc_cookie_for_section (&cookie, sec);
+        }
+    }
+
+  return ret;
+}
+
+static bfd_boolean
+_bfd_coff_gc_mark_extra_sections (struct bfd_link_info *info,
+                                 coff_gc_mark_hook_fn mark_hook ATTRIBUTE_UNUSED)
+{
+  bfd *ibfd;
+
+  for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
+    {
+      asection *isec;
+      bfd_boolean some_kept;
+
+      if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour)
+       continue;
+
+      /* Ensure all linker created sections are kept, and see whether
+        any other section is already marked.  */
+      some_kept = FALSE;
+      for (isec = ibfd->sections; isec != NULL; isec = isec->next)
+       {
+         if ((isec->flags & SEC_LINKER_CREATED) != 0)
+           isec->gc_mark = 1;
+         else if (isec->gc_mark)
+           some_kept = TRUE;
+       }
+
+      /* If no section in this file will be kept, then we can
+        toss out debug sections.  */
+      if (!some_kept)
+       continue;
+
+      /* Keep debug and special sections like .comment when they are
+        not part of a group, or when we have single-member groups.  */
+      for (isec = ibfd->sections; isec != NULL; isec = isec->next)
+       if ((isec->flags & SEC_DEBUGGING) != 0
+           || (isec->flags & (SEC_ALLOC | SEC_LOAD | SEC_RELOC)) == 0)
+         isec->gc_mark = 1;
+    }
+  return TRUE;
+}
+
+/* Sweep symbols in swept sections.  Called via coff_link_hash_traverse.  */
+
+static bfd_boolean
+coff_gc_sweep_symbol (struct coff_link_hash_entry *h,
+                     void *data ATTRIBUTE_UNUSED)
+{
+  if (h->root.type == bfd_link_hash_warning)
+    h = (struct coff_link_hash_entry *) h->root.u.i.link;
+
+  if ((h->root.type == bfd_link_hash_defined
+       || h->root.type == bfd_link_hash_defweak)
+      && !h->root.u.def.section->gc_mark
+      && !(h->root.u.def.section->owner->flags & DYNAMIC))
+    {
+      /* Do our best to hide the symbol.  */
+      h->root.u.def.section = bfd_und_section_ptr;
+      h->symbol_class = C_HIDDEN;
+    }
+
+  return TRUE;
+}
+
+/* The sweep phase of garbage collection.  Remove all garbage sections.  */
+
+typedef bfd_boolean (*gc_sweep_hook_fn)
+  (bfd *, struct bfd_link_info *, asection *, const struct internal_reloc *);
+
+static bfd_boolean
+coff_gc_sweep (bfd *abfd ATTRIBUTE_UNUSED, struct bfd_link_info *info)
+{
+  bfd *sub;
+
+  for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
+    {
+      asection *o;
+
+      if (bfd_get_flavour (sub) != bfd_target_coff_flavour)
+       continue;
+
+      for (o = sub->sections; o != NULL; o = o->next)
+       {
+           /* Keep debug and special sections.  */
+          if ((o->flags & (SEC_DEBUGGING | SEC_LINKER_CREATED)) != 0
+             || (o->flags & (SEC_ALLOC | SEC_LOAD | SEC_RELOC)) == 0)
+           o->gc_mark = 1;
+          else if (CONST_STRNEQ (o->name, ".idata")
+                  || CONST_STRNEQ (o->name, ".pdata")
+                  || CONST_STRNEQ (o->name, ".xdata")
+                  || CONST_STRNEQ (o->name, ".rsrc"))
+           o->gc_mark = 1;
+
+         if (o->gc_mark)
+           continue;
+
+         /* Skip sweeping sections already excluded.  */
+         if (o->flags & SEC_EXCLUDE)
+           continue;
+
+         /* Since this is early in the link process, it is simple
+            to remove a section from the output.  */
+         o->flags |= SEC_EXCLUDE;
+
+         if (info->print_gc_sections && o->size != 0)
+            _bfd_error_handler (_("Removing unused section '%s' in file '%B'"), sub, o->name);
+
+#if 0
+         /* But we also have to update some of the relocation
+            info we collected before.  */
+         if (gc_sweep_hook
+             && (o->flags & SEC_RELOC) != 0
+             && o->reloc_count > 0
+             && !bfd_is_abs_section (o->output_section))
+           {
+             struct internal_reloc *internal_relocs;
+             bfd_boolean r;
+
+             internal_relocs
+               = _bfd_coff_link_read_relocs (o->owner, o, NULL, NULL,
+                                            info->keep_memory);
+             if (internal_relocs == NULL)
+               return FALSE;
+
+             r = (*gc_sweep_hook) (o->owner, info, o, internal_relocs);
+
+             if (coff_section_data (o)->relocs != internal_relocs)
+               free (internal_relocs);
+
+             if (!r)
+               return FALSE;
+           }
+#endif
+       }
+    }
+
+  /* Remove the symbols that were in the swept sections from the dynamic
+     symbol table.  */
+  coff_link_hash_traverse (coff_hash_table (info), coff_gc_sweep_symbol,
+                          NULL);
+
+  return TRUE;
+}
+
+/* Keep all sections containing symbols undefined on the command-line,
+   and the section containing the entry symbol.  */
+
+static void
+_bfd_coff_gc_keep (struct bfd_link_info *info)
+{
+  struct bfd_sym_chain *sym;
+
+  for (sym = info->gc_sym_list; sym != NULL; sym = sym->next)
+    {
+      struct coff_link_hash_entry *h;
+
+      h = coff_link_hash_lookup (coff_hash_table (info), sym->name,
+                               FALSE, FALSE, FALSE);
+
+      if (h != NULL
+         && (h->root.type == bfd_link_hash_defined
+             || h->root.type == bfd_link_hash_defweak)
+         && !bfd_is_abs_section (h->root.u.def.section))
+       h->root.u.def.section->flags |= SEC_KEEP;
+    }
+}
+
+/* Do mark and sweep of unused sections.  */
+
+bfd_boolean
+bfd_coff_gc_sections (bfd *abfd ATTRIBUTE_UNUSED, struct bfd_link_info *info)
+{
+  bfd *sub;
+
+  /* FIXME: Should we implement this? */
+#if 0
+  const bfd_coff_backend_data *bed = coff_backend_info (abfd);
+
+  if (!bed->can_gc_sections
+      || !is_coff_hash_table (info->hash))
+    {
+      (*_bfd_error_handler)(_("Warning: gc-sections option ignored"));
+      return TRUE;
+    }
+#endif
+
+  _bfd_coff_gc_keep (info);
+
+  /* Grovel through relocs to find out who stays ...  */
+  for (sub = info->input_bfds; sub != NULL; sub = sub->link.next)
+    {
+      asection *o;
+
+      if (bfd_get_flavour (sub) != bfd_target_coff_flavour)
+        continue;
+
+      for (o = sub->sections; o != NULL; o = o->next)
+        {
+         if (((o->flags & (SEC_EXCLUDE | SEC_KEEP)) == SEC_KEEP
+              || CONST_STRNEQ (o->name, ".vectors")
+              || CONST_STRNEQ (o->name, ".ctors")
+              || CONST_STRNEQ (o->name, ".dtors"))
+             && !o->gc_mark)
+           {
+             if (!_bfd_coff_gc_mark (info, o, _bfd_coff_gc_mark_hook))
+               return FALSE;
+           }
+        }
+    }
+
+  /* Allow the backend to mark additional target specific sections.  */
+  _bfd_coff_gc_mark_extra_sections (info, _bfd_coff_gc_mark_hook);
+
+  /* ... and mark SEC_EXCLUDE for those that go.  */
+  return coff_gc_sweep (abfd, info);
+}
index 34e71a894478c6b90afc7ebdd46b42c2aa1f980f..83775c681b98a923fa5bd3a7e7d84dbcb26a9581 100644 (file)
@@ -265,6 +265,16 @@ struct coff_link_hash_table
   struct stab_info stab_info;
 };
 
+struct coff_reloc_cookie
+{
+  struct internal_reloc *         rels;
+  struct internal_reloc *         rel;
+  struct internal_reloc *         relend;
+  struct coff_symbol_struct *     symbols;     /* Symtab for input bfd.  */
+  bfd *                           abfd;
+  struct coff_link_hash_entry **  sym_hashes;
+};
+
 /* Look up an entry in a COFF linker hash table.  */
 
 #define coff_link_hash_lookup(table, string, create, copy, follow)     \
@@ -562,6 +572,8 @@ extern bfd_boolean _bfd_coff_link_input_bfd
 extern bfd_boolean _bfd_coff_reloc_link_order
   (bfd *, struct coff_final_link_info *, asection *,
    struct bfd_link_order *);
+extern bfd_boolean bfd_coff_gc_sections
+  (bfd *, struct bfd_link_info *);
 
 
 #define coff_get_section_contents_in_window \
index ee72de3c98b2d4e52970a7ec2a031197a19ff7b6..124e603fc95fe64102e39645e8c1765970afcf92 100644 (file)
@@ -269,6 +269,16 @@ struct coff_link_hash_table
   struct stab_info stab_info;
 };
 
+struct coff_reloc_cookie
+{
+  struct internal_reloc *         rels;
+  struct internal_reloc *         rel;
+  struct internal_reloc *         relend;
+  struct coff_symbol_struct *     symbols;     /* Symtab for input bfd.  */
+  bfd *                           abfd;
+  struct coff_link_hash_entry **  sym_hashes;
+};
+
 /* Look up an entry in a COFF linker hash table.  */
 
 #define coff_link_hash_lookup(table, string, create, copy, follow)     \
@@ -566,6 +576,8 @@ extern bfd_boolean _bfd_coff_link_input_bfd
 extern bfd_boolean _bfd_coff_reloc_link_order
   (bfd *, struct coff_final_link_info *, asection *,
    struct bfd_link_order *);
+extern bfd_boolean bfd_coff_gc_sections
+  (bfd *, struct bfd_link_info *);
 
 
 #define coff_get_section_contents_in_window \
@@ -673,6 +685,10 @@ enum coff_symbol_classification
   COFF_SYMBOL_PE_SECTION
 };
 
+typedef asection * (*coff_gc_mark_hook_fn)
+  (asection *, struct bfd_link_info *, struct internal_reloc *,
+   struct coff_link_hash_entry *, struct internal_syment *);
+
 typedef struct
 {
   void (*_bfd_coff_swap_aux_in)
index 7324717c5434bea807dd5cd8a6bd4afbcaec34a9..9228ead9ebf17affd3f1027e7b1f523a2476e83f 100644 (file)
@@ -1,3 +1,15 @@
+2015-07-03   Kai Tietz  <ktietz@redhat.com>
+
+       PR ld/11539
+       * scripttempl/pep.sc: Mark .idata*, .CRT*, .tls*,
+       .rsrc*, .init, .ctor*, .dtor*, .fini, .jcr,
+       .eh_frame, .pdata. .xdata, and .gcc_except_table sections
+       as KEEP.
+       * scripttempl/pe.sc: Likewise.
+       * ld.texinfo: Document that --gc-sections has experimental support
+       for COFF and PE targets.
+       * NEWS: Mention experimental support.
+
 2015-07-03  Alan Modra  <amodra@gmail.com>
 
        * Makefile.am (eelf32or1k.c, eelf32or1k_linux.c): Depend on ELF_DEPS.
diff --git a/ld/NEWS b/ld/NEWS
index 140d3c95905030396d8da25174ec507cbb722220..e3de4328095c53f9463060da535835430ee931d3 100644 (file)
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -1,5 +1,8 @@
 -*- text -*-
 
+* Experimental support for linker garbage collection (--gc-sections)
+  has been enabled for COFF and PE based targets.
+
 * New command line option for ELF targets to compress DWARF debug
   sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
 
index e12b64affb509cd4f9ea8840785b37e73860c950..246f545dd943b4ecb4ca7f7a8975bc8c5726dd0a 100644 (file)
@@ -1436,7 +1436,9 @@ it ends in a @code{.exe} suffix.
 Enable garbage collection of unused input sections.  It is ignored on
 targets that do not support this option.  The default behaviour (of not
 performing this garbage collection) can be restored by specifying
-@samp{--no-gc-sections} on the command line.
+@samp{--no-gc-sections} on the command line.  Note that garbage
+collection for COFF and PE format targets is supported, but the
+implementation is currently considered to be experimental.
 
 @samp{--gc-sections} decides which input sections are used by
 examining symbols and relocations.  The section containing the entry
index fbc38e8714cd4efa92d7db352b25a8bdd9fa4161..0adc78bf5126a9e83df210d491a9b4d4dc83ae92 100644 (file)
@@ -30,29 +30,29 @@ if test "${RELOCATING}"; then
              *(SORT(.rdata$*))'
   fi
   R_IDATA234='
-    SORT(*)(.idata$2)
-    SORT(*)(.idata$3)
+    KEEP (SORT(*)(.idata$2))
+    KEEP (SORT(*)(.idata$3))
     /* These zeroes mark the end of the import list.  */
     LONG (0); LONG (0); LONG (0); LONG (0); LONG (0);
-    SORT(*)(.idata$4)'
-  R_IDATA5='SORT(*)(.idata$5)'
+    KEEP (SORT(*)(.idata$4))'
+  R_IDATA5='KEEP (SORT(*)(.idata$5))'
   R_IDATA67='
-    SORT(*)(.idata$6)
-    SORT(*)(.idata$7)'
-  R_CRT_XC='*(SORT(.CRT$XC*))  /* C initialization */'
-  R_CRT_XI='*(SORT(.CRT$XI*))  /* C++ initialization */'
-  R_CRT_XL='*(SORT(.CRT$XL*))  /* TLS callbacks */'
-  R_CRT_XP='*(SORT(.CRT$XP*))  /* Pre-termination */'
-  R_CRT_XT='*(SORT(.CRT$XT*))  /* Termination */'
+    KEEP (SORT(*)(.idata$6))
+    KEEP (SORT(*)(.idata$7))'
+  R_CRT_XC='KEEP (*(SORT(.CRT$XC*)))  /* C initialization */'
+  R_CRT_XI='KEEP (*(SORT(.CRT$XI*)))  /* C++ initialization */'
+  R_CRT_XL='KEEP (*(SORT(.CRT$XL*)))  /* TLS callbacks */'
+  R_CRT_XP='KEEP (*(SORT(.CRT$XP*)))  /* Pre-termination */'
+  R_CRT_XT='KEEP (*(SORT(.CRT$XT*)))  /* Termination */'
   R_TLS='
-    *(.tls$AAA)
-    *(.tls)
-    *(.tls$)
-    *(SORT(.tls$*))
-    *(.tls$ZZZ)'
+    KEEP (*(.tls$AAA))
+    KEEP (*(.tls))
+    KEEP (*(.tls$))
+    KEEP (*(SORT(.tls$*)))
+    KEEP (*(.tls$ZZZ))'
   R_RSRC='
-    *(.rsrc)
-    *(.rsrc$*)'
+    KEEP (*(.rsrc))
+    KEEP (*(.rsrc$*))'
 else
   R_TEXT=
   R_DATA=
@@ -85,7 +85,7 @@ SECTIONS
   ${RELOCATING+. = ALIGN(__section_alignment__);}
   .text ${RELOCATING+ __image_base__ + ( __section_alignment__ < ${TARGET_PAGE_SIZE} ? . : __section_alignment__ )} :
   {
-    ${RELOCATING+ *(.init)}
+    ${RELOCATING+ KEEP(*(.init))}
     *(.text)
     ${R_TEXT}
     ${RELOCATING+ *(.text.*)}
@@ -116,7 +116,7 @@ SECTIONS
     *(.data)
     *(.data2)
     ${R_DATA}
-    *(.jcr)
+    KEEP(*(.jcr))
     ${RELOCATING+__data_end__ = . ;}
     ${RELOCATING+*(.data_cygwin_nocopy)}
   }
@@ -136,12 +136,12 @@ SECTIONS
 
   .eh_frame ${RELOCATING+BLOCK(__section_alignment__)} :
   {
-    *(.eh_frame*)
+    KEEP(*(.eh_frame*))
   }
 
   .pdata ${RELOCATING+BLOCK(__section_alignment__)} :
   {
-    *(.pdata)
+    KEEP(*(.pdata))
   }
 
   .bss ${RELOCATING+BLOCK(__section_alignment__)} :
index 50b410472129c9f3e8f16c6432a227e4cff57a9f..6e78b2178190b982aa0a332de1bb3c597deb8a14 100644 (file)
@@ -30,29 +30,29 @@ if test "${RELOCATING}"; then
              *(SORT(.rdata$*))'
   fi
   R_IDATA234='
-    SORT(*)(.idata$2)
-    SORT(*)(.idata$3)
+    KEEP (SORT(*)(.idata$2))
+    KEEP (SORT(*)(.idata$3))
     /* These zeroes mark the end of the import list.  */
     LONG (0); LONG (0); LONG (0); LONG (0); LONG (0);
-    SORT(*)(.idata$4)'
+    KEEP (SORT(*)(.idata$4))'
   R_IDATA5='SORT(*)(.idata$5)'
   R_IDATA67='
-    SORT(*)(.idata$6)
-    SORT(*)(.idata$7)'
-  R_CRT_XC='*(SORT(.CRT$XC*))  /* C initialization */'
-  R_CRT_XI='*(SORT(.CRT$XI*))  /* C++ initialization */'
-  R_CRT_XL='*(SORT(.CRT$XL*))  /* TLS callbacks */'
-  R_CRT_XP='*(SORT(.CRT$XP*))  /* Pre-termination */'
-  R_CRT_XT='*(SORT(.CRT$XT*))  /* Termination */'
+    KEEP (SORT(*)(.idata$6))
+    KEEP (SORT(*)(.idata$7))'
+  R_CRT_XC='KEEP (*(SORT(.CRT$XC*)))  /* C initialization */'
+  R_CRT_XI='KEEP (*(SORT(.CRT$XI*)))  /* C++ initialization */'
+  R_CRT_XL='KEEP (*(SORT(.CRT$XL*)))  /* TLS callbacks */'
+  R_CRT_XP='KEEP (*(SORT(.CRT$XP*)))  /* Pre-termination */'
+  R_CRT_XT='KEEP (*(SORT(.CRT$XT*)))  /* Termination */'
   R_TLS='
-    *(.tls$AAA)
-    *(.tls)
-    *(.tls$)
-    *(SORT(.tls$*))
-    *(.tls$ZZZ)'
+    KEEP (*(.tls$AAA))
+    KEEP (*(.tls))
+    KEEP (*(.tls$))
+    KEEP (*(SORT(.tls$*)))
+    KEEP (*(.tls$ZZZ))'
   R_RSRC='
-    *(.rsrc)
-    *(.rsrc$*)'
+    KEEP (*(.rsrc))
+    KEEP (*(.rsrc$*))'
 else
   R_TEXT=
   R_DATA=
@@ -85,7 +85,7 @@ SECTIONS
   ${RELOCATING+. = ALIGN(__section_alignment__);}
   .text ${RELOCATING+ __image_base__ + ( __section_alignment__ < ${TARGET_PAGE_SIZE} ? . : __section_alignment__ )} :
   {
-    ${RELOCATING+ *(.init)}
+    ${RELOCATING+ KEEP(*(.init))}
     *(.text)
     ${R_TEXT}
     ${RELOCATING+ *(.text.*)}
@@ -94,14 +94,22 @@ SECTIONS
     *(.glue_7)
     ${CONSTRUCTING+. = ALIGN(8);}
     ${CONSTRUCTING+ ___CTOR_LIST__ = .; __CTOR_LIST__ = . ;
-                       LONG (-1); LONG (-1);*(.ctors); *(.ctor); *(SORT(.ctors.*));  LONG (0); LONG (0); }
+                       LONG (-1); LONG (-1);
+                       KEEP (*(.ctors));
+                       KEEP (*(.ctor));
+                       KEEP (*(SORT(.ctors.*)));
+                       LONG (0); LONG (0); }
     ${CONSTRUCTING+ ___DTOR_LIST__ = .; __DTOR_LIST__ = . ;
-                       LONG (-1); LONG (-1); *(.dtors); *(.dtor); *(SORT(.dtors.*));  LONG (0); LONG (0); }
-    ${RELOCATING+ *(.fini)}
+                       LONG (-1); LONG (-1);
+                       KEEP (*(.dtors));
+                       KEEP (*(.dtor));
+                       KEEP (*(SORT(.dtors.*)));
+                       LONG (0); LONG (0); }
+    ${RELOCATING+ KEEP (*(.fini))}
     /* ??? Why is .gcc_exc here?  */
     ${RELOCATING+ *(.gcc_exc)}
     ${RELOCATING+PROVIDE (etext = .);}
-    ${RELOCATING+ *(.gcc_except_table)}
+    ${RELOCATING+ KEEP (*(.gcc_except_table))}
   }
 
   /* The Cygwin32 library uses a section to avoid copying certain data
@@ -116,7 +124,7 @@ SECTIONS
     *(.data)
     *(.data2)
     ${R_DATA}
-    *(.jcr)
+    KEEP(*(.jcr))
     ${RELOCATING+__data_end__ = . ;}
     ${RELOCATING+*(.data_cygwin_nocopy)}
   }
@@ -136,17 +144,17 @@ SECTIONS
 
   .eh_frame ${RELOCATING+BLOCK(__section_alignment__)} :
   {
-    *(.eh_frame*)
+    KEEP (*(.eh_frame*))
   }
 
   .pdata ${RELOCATING+BLOCK(__section_alignment__)} :
   {
-    *(.pdata*)
+    KEEP(*(.pdata*))
   }
 
   .xdata ${RELOCATING+BLOCK(__section_alignment__)} :
   {
-    *(.xdata*)
+    KEEP(*(.xdata*))
   }
 
   .bss ${RELOCATING+BLOCK(__section_alignment__)} :
index 0e611b99c106f20a04c8b25e12ce0c4e7da592fc..03fff184c02fd1cdf288072d671a9378ea8a4be1 100644 (file)
@@ -1,3 +1,10 @@
+2015-07-03   Kai Tietz  <ktietz@redhat.com>
+            Nick Clifton  <nickc@redhat.com>
+
+       PR ld/11539
+       * lib/ld-lib.exp (check_gc_sections_available): Do not
+       automatically fail for cygwin and mingw targets.
+
 2015-07-01  Sandra Loosemore  <sandra@codesourcery.com>
            Cesar Philippidis  <cesar@codesourcery.com>
 
index 9e22706243ee55dc92a5ade4ecdf88039fceab05..0cab4d3946a9db34f16e5a6650b1e115039b5b42 100644 (file)
@@ -1610,9 +1610,7 @@ proc check_gc_sections_available { } {
            || [istarget i860-*-*]
            || [istarget ia64-*-*]
            || [istarget mep-*-*]
-           || [istarget mn10200-*-*]
-           || [istarget *-*-cygwin]
-           || [istarget *-*-mingw*] } {
+           || [istarget mn10200-*-*] } {
            set gc_sections_available_saved 0
            return 0
        }