Add support for creating ELF import libraries

2016-07-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>

bfd/
	* elf-bfd.h (elf_backend_filter_implib_symbols): Declare backend hook.
	(_bfd_elf_filter_global_symbols): Declare.
	* elf.c (_bfd_elf_filter_global_symbols): New function.
	* elflink.c (elf_filter_global_symbols): Likewise.
	(elf_output_implib): Likewise.
	(bfd_elf_final_link): Call above function, failing if it does.
	* elfxx-target.h (elf_backend_filter_implib_symbols): Define macro and
	default it to NULL.
	(elf_backend_copy_indirect_symbol): Fix spacing.
	(elf_backend_hide_symbol): Likewise.
	(elfNN_bed): Initialize elf_backend_filter_implib_symbols backend hook.

include/
	* bfdlink.h (struct bfd_link_info): Declare new ldscript_def and
	out_implib_bfd fields.

2016-07-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>
	    Nick Clifton  <nickc@redhat.com>

ld/
	* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Open import
	library file for writing and initialize implib_bfd field of link_info
	structure.
	* emultempl/pe.em (pe_implib_filename): Remove variable declaration.
	(OPTION_IMPLIB_FILENAME): Remove macro definition.
	(gld${EMULATION_NAME}_add_options): Remove --out-implib option.
	(gld_${EMULATION_NAME}_list_options): Likewise.
	(gld${EMULATION_NAME}_handle_option): Likewise.
	(gld_${EMULATION_NAME}_finish): Use command_line.out_implib_filename
	instead of pe_implib_filename.
	* emultempl/pep.em (pep_implib_filename): Remove variable declaration.
	(OPTION_IMPLIB_FILENAME): Remove enumerator.
	(gld${EMULATION_NAME}_add_options): Remove --out-implib option.
	(gld_${EMULATION_NAME}_list_options): Likewise.
	(gld${EMULATION_NAME}_handle_option): Likewise.
	(gld_${EMULATION_NAME}_finish): Use command_line.out_implib_filename
	instead of pep_implib_filename.
	* ld.h (args_type): Declare new out_implib_filename field.
	* ld.texinfo (--out-implib): Move documentation to arch-independent
	part and rephrase to apply to ELF targets.
	* ldexp.c (exp_fold_tree_1): Set ldscript_def field to 1 for symbols
	defined in linker scripts.
	* ldlex.h (enum option_values): Declare new OPTION_OUT_IMPLIB
	enumerator.
	* lexsup.c (ld_options): Add entry for new --out-implib switch.
	(parse_args): Handle OPTION_OUT_IMPLIB case.
	* testsuite/ld-elf/elf.exp (Generate empty import library): New test.
	(Generate import library): Likewise.
	* testsuite/ld-elf/implib.s: Likewise.
	* testsuite/ld-elf/implib.rd: New file.
	* testsuite/ld-elf/empty-implib.out: Likewise

3 files changed, 21 insertions, 19 deletions

diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em
index 47fa549..dd4d35a 100644
--- a/ld/emultempl/elf32.em
+++ b/ld/emultempl/elf32.em
@@ -1027,6 +1027,20 @@ gld${EMULATION_NAME}_after_open (void)
   if (!is_elf_hash_table (htab))
     return;
 
+  if (command_line.out_implib_filename)
+    {
+      unlink_if_ordinary (command_line.out_implib_filename);
+      link_info.out_implib_bfd
+	= bfd_openw (command_line.out_implib_filename,
+		     bfd_get_target (link_info.output_bfd));
+
+      if (link_info.out_implib_bfd == NULL)
+	{
+	  einfo ("%F%s: Can't open for writing: %E\n",
+		 command_line.out_implib_filename);
+	}
+    }
+
   if (emit_note_gnu_build_id != NULL)
     {
       bfd *abfd;
diff --git a/ld/emultempl/pe.em b/ld/emultempl/pe.em
index c13fa4d..7b8fec7 100644
--- a/ld/emultempl/pe.em
+++ b/ld/emultempl/pe.em
@@ -138,7 +138,6 @@ static const char *emit_build_id;
 #ifdef DLL_SUPPORT
 static int pe_enable_stdcall_fixup = -1; /* 0=disable 1=enable.  */
 static char *pe_out_def_filename = NULL;
-static char *pe_implib_filename = NULL;
 static int pe_enable_auto_image_base = 0;
 static unsigned long pe_auto_image_base = 0x61500000;
 static char *pe_dll_search_prefix = NULL;
@@ -228,8 +227,7 @@ fragment <<EOF
 #define OPTION_STDCALL_ALIASES		(OPTION_KILL_ATS + 1)
 #define OPTION_ENABLE_STDCALL_FIXUP	(OPTION_STDCALL_ALIASES + 1)
 #define OPTION_DISABLE_STDCALL_FIXUP	(OPTION_ENABLE_STDCALL_FIXUP + 1)
-#define OPTION_IMPLIB_FILENAME		(OPTION_DISABLE_STDCALL_FIXUP + 1)
-#define OPTION_THUMB_ENTRY		(OPTION_IMPLIB_FILENAME + 1)
+#define OPTION_THUMB_ENTRY		(OPTION_DISABLE_STDCALL_FIXUP + 1)
 #define OPTION_WARN_DUPLICATE_EXPORTS	(OPTION_THUMB_ENTRY + 1)
 #define OPTION_IMP_COMPAT		(OPTION_WARN_DUPLICATE_EXPORTS + 1)
 #define OPTION_ENABLE_AUTO_IMAGE_BASE	(OPTION_IMP_COMPAT + 1)
@@ -323,7 +321,6 @@ gld${EMULATION_NAME}_add_options
     {"add-stdcall-alias", no_argument, NULL, OPTION_STDCALL_ALIASES},
     {"enable-stdcall-fixup", no_argument, NULL, OPTION_ENABLE_STDCALL_FIXUP},
     {"disable-stdcall-fixup", no_argument, NULL, OPTION_DISABLE_STDCALL_FIXUP},
-    {"out-implib", required_argument, NULL, OPTION_IMPLIB_FILENAME},
     {"warn-duplicate-exports", no_argument, NULL, OPTION_WARN_DUPLICATE_EXPORTS},
     /* getopt() allows abbreviations, so we do this to stop it from
        treating -c as an abbreviation for these --compat-implib.  */
@@ -461,7 +458,6 @@ gld_${EMULATION_NAME}_list_options (FILE *file)
   fprintf (file, _("                                     export, place into import library instead.\n"));
   fprintf (file, _("  --export-all-symbols               Automatically export all globals to DLL\n"));
   fprintf (file, _("  --kill-at                          Remove @nn from exported symbols\n"));
-  fprintf (file, _("  --out-implib <file>                Generate import library\n"));
   fprintf (file, _("  --output-def <file>                Generate a .DEF file for the built DLL\n"));
   fprintf (file, _("  --warn-duplicate-exports           Warn about duplicate exports\n"));
   fprintf (file, _("  --compat-implib                    Create backward compatible import libs;\n\
@@ -804,9 +800,6 @@ gld${EMULATION_NAME}_handle_option (int optc)
     case OPTION_DISABLE_STDCALL_FIXUP:
       pe_enable_stdcall_fixup = 0;
       break;
-    case OPTION_IMPLIB_FILENAME:
-      pe_implib_filename = xstrdup (optarg);
-      break;
     case OPTION_WARN_DUPLICATE_EXPORTS:
       pe_dll_warn_dup_exports = 1;
       break;
@@ -2070,8 +2063,9 @@ gld_${EMULATION_NAME}_finish (void)
     )
     {
       pe_dll_fill_sections (link_info.output_bfd, &link_info);
-      if (pe_implib_filename)
-	pe_dll_generate_implib (pe_def_file, pe_implib_filename, &link_info);
+      if (command_line.out_implib_filename)
+	pe_dll_generate_implib (pe_def_file, command_line.out_implib_filename,
+				&link_info);
     }
 #if defined(TARGET_IS_shpe)
   /* ARM doesn't need relocs.  */
diff --git a/ld/emultempl/pep.em b/ld/emultempl/pep.em
index ab7c473..60deeed 100644
--- a/ld/emultempl/pep.em
+++ b/ld/emultempl/pep.em
@@ -153,7 +153,6 @@ static const char *emit_build_id;
 #ifdef DLL_SUPPORT
 static int    pep_enable_stdcall_fixup = 1; /* 0=disable 1=enable (default).  */
 static char * pep_out_def_filename = NULL;
-static char * pep_implib_filename = NULL;
 static int    pep_enable_auto_image_base = 0;
 static char * pep_dll_search_prefix = NULL;
 #endif
@@ -217,7 +216,6 @@ enum options
   OPTION_STDCALL_ALIASES,
   OPTION_ENABLE_STDCALL_FIXUP,
   OPTION_DISABLE_STDCALL_FIXUP,
-  OPTION_IMPLIB_FILENAME,
   OPTION_WARN_DUPLICATE_EXPORTS,
   OPTION_IMP_COMPAT,
   OPTION_ENABLE_AUTO_IMAGE_BASE,
@@ -296,7 +294,6 @@ gld${EMULATION_NAME}_add_options
     {"add-stdcall-alias", no_argument, NULL, OPTION_STDCALL_ALIASES},
     {"enable-stdcall-fixup", no_argument, NULL, OPTION_ENABLE_STDCALL_FIXUP},
     {"disable-stdcall-fixup", no_argument, NULL, OPTION_DISABLE_STDCALL_FIXUP},
-    {"out-implib", required_argument, NULL, OPTION_IMPLIB_FILENAME},
     {"warn-duplicate-exports", no_argument, NULL, OPTION_WARN_DUPLICATE_EXPORTS},
     /* getopt() allows abbreviations, so we do this to stop it from
        treating -c as an abbreviation for these --compat-implib.  */
@@ -427,7 +424,6 @@ gld_${EMULATION_NAME}_list_options (FILE *file)
   fprintf (file, _("                                     export, place into import library instead.\n"));
   fprintf (file, _("  --export-all-symbols               Automatically export all globals to DLL\n"));
   fprintf (file, _("  --kill-at                          Remove @nn from exported symbols\n"));
-  fprintf (file, _("  --out-implib <file>                Generate import library\n"));
   fprintf (file, _("  --output-def <file>                Generate a .DEF file for the built DLL\n"));
   fprintf (file, _("  --warn-duplicate-exports           Warn about duplicate exports.\n"));
   fprintf (file, _("  --compat-implib                    Create backward compatible import libs;\n\
@@ -761,9 +757,6 @@ gld${EMULATION_NAME}_handle_option (int optc)
     case OPTION_DISABLE_STDCALL_FIXUP:
       pep_enable_stdcall_fixup = 0;
       break;
-    case OPTION_IMPLIB_FILENAME:
-      pep_implib_filename = xstrdup (optarg);
-      break;
     case OPTION_WARN_DUPLICATE_EXPORTS:
       pep_dll_warn_dup_exports = 1;
       break;
@@ -1851,8 +1844,9 @@ gld_${EMULATION_NAME}_finish (void)
 	  && pep_def_file->num_exports != 0))
     {
       pep_dll_fill_sections (link_info.output_bfd, &link_info);
-      if (pep_implib_filename)
-	pep_dll_generate_implib (pep_def_file, pep_implib_filename, &link_info);
+      if (command_line.out_implib_filename)
+	pep_dll_generate_implib (pep_def_file,
+				 command_line.out_implib_filename, &link_info);
     }
 
   if (pep_out_def_filename)