Fixes for the magic number used in PDP11 AOUT binaries.

	PR ld/25677
include	* aout/aout64.h (N_DATADDR): Add IMAGIC case.

bfd	* pdp11.c: Add implementation of --imagic option.
	(adjust_o_magic): Fix objcopy --extract-symbol test.
	* libaout.h (enum aout_magic): Add i_magic.

ld	* emulparams/pdp11.sh (SCRIPT_NAME): Change to pdp11.
	(EXTRA_EM_FILE): New, add emulation file pdp11.
	* scripttempl/pdp11.sc: New, derived from aout.sc without
	irrelevant input sections.
	* emultempl/pdp11.em (_add_options, _handle_option)
	(_list_options): New. Add options -z, --imagic for pdp11-aout.
	(_before_parse): Make --omagic be default instead of --nmagic.
	(_get_script): Modify special-case linker script for --imagic.
	* lexsup.c (parse_args): Explictly set config.text_read_only for -n.
	* ld.texi (Options): Add documentation of PDP11-specific options.
	(Options): Fix unrelated typo to --no-compact-branches.
	* gen-doc.texi: @set PDP11.
	* testsuite/ld-pdp11/pdp11.exp: New, start pdp11 testing.
	* testsuite/ld-pdp11/sections.s: New, source for options tests.
	* testsuite/ld-pdp11/imagic.d: New, test --imagic format.
	* testsuite/ld-pdp11/imagicz.d: New, test -z (imagic) format.
	* testsuite/ld-pdp11/nmagic.d: New, test --nmagic format.
	* testsuite/ld-pdp11/omagic.d: New, test --omagic format.

3 files changed, 68 insertions, 4 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 120fb38..0ef3b2f 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,10 @@
+2020-04-14  Stephen Casner  <casner@acm.org>
+
+	PR ld/25677
+	* pdp11.c: Add implementation of --imagic option.
+	(adjust_o_magic): Fix objcopy --extract-symbol test.
+	* libaout.h (enum aout_magic): Add i_magic.
+
 2020-04-07  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 	    Nick Clifton  <nickc@redhat.com>
 
diff --git a/bfd/libaout.h b/bfd/libaout.h
index bdf917e..61746db 100644
--- a/bfd/libaout.h
+++ b/bfd/libaout.h
@@ -359,7 +359,8 @@ enum aout_magic {
   undecided_magic = 0,
   z_magic,
   o_magic,
-  n_magic
+  n_magic,
+  i_magic
 };
 
 struct aoutdata
diff --git a/bfd/pdp11.c b/bfd/pdp11.c
index c13e742..1f8c406 100644
--- a/bfd/pdp11.c
+++ b/bfd/pdp11.c
@@ -63,6 +63,7 @@
 #define N_SET_FLAGS(execp, flags) do { } while (0)
 #define N_BADMAG(x) (N_MAGIC(x) != OMAGIC	\
 		     && N_MAGIC(x) != NMAGIC	\
+		     && N_MAGIC(x) != IMAGIC	\
 		     && N_MAGIC(x) != ZMAGIC)
 
 #include "sysdep.h"
@@ -90,7 +91,8 @@ struct pdp11_external_exec
 #define	A_MAGIC2	NMAGIC
 #define NMAGIC		0410	/* Pure executable.  */
 #define ZMAGIC		0413	/* Demand-paged executable.  */
-#define	A_MAGIC3	0411	/* Separated I&D.  */
+#define	IMAGIC		0411	/* Separated I&D.  */
+#define	A_MAGIC3	IMAGIC
 #define	A_MAGIC4	0405	/* Overlay.  */
 #define	A_MAGIC5	0430	/* Auto-overlay (nonseparate).  */
 #define	A_MAGIC6	0431	/* Auto-overlay (separate).  */
@@ -242,6 +244,10 @@ struct aout_final_link_info
   struct external_nlist *output_syms;
 };
 
+/* Copy of the link_info.separate_code boolean to select the output format with
+   separate instruction and data spaces selected by --imagic */
+static bfd_boolean separate_i_d = FALSE;
+
 reloc_howto_type howto_table_pdp11[] =
 {
   /* type	       rs size bsz  pcrel bitpos ovrf			  sf name     part_inpl readmask  setmask    pcdone */
@@ -498,6 +504,8 @@ NAME (aout, some_aout_object_p) (bfd *abfd,
     }
   else if (N_MAGIC (execp) == OMAGIC)
     adata (abfd).magic = o_magic;
+  else if (N_MAGIC (execp) == IMAGIC)
+    adata (abfd).magic = i_magic;
   else
     {
       /* Should have been checked with N_BADMAG before this routine
@@ -825,7 +833,7 @@ adjust_o_magic (bfd *abfd, struct internal_exec *execp)
       vma += pad;
       bss->vma = vma;
     }
-  else
+  else if (data->size > 0 || bss->size > 0) /* PR25677: for objcopy --extract-symbol */
     {
       /* The VMA of the .bss section is set by the VMA of the
 	 .data section plus the size of the .data section.  We may
@@ -988,6 +996,47 @@ adjust_n_magic (bfd *abfd, struct internal_exec *execp)
   N_SET_MAGIC (execp, NMAGIC);
 }
 
+static void
+adjust_i_magic (bfd *abfd, struct internal_exec *execp)
+{
+  file_ptr pos = adata (abfd).exec_bytes_size;
+  bfd_vma vma = 0;
+  int pad;
+  asection *text = obj_textsec (abfd);
+  asection *data = obj_datasec (abfd);
+  asection *bss = obj_bsssec (abfd);
+
+  /* Text.  */
+  text->filepos = pos;
+  if (!text->user_set_vma)
+    text->vma = vma;
+  else
+    vma = text->vma;
+  pos += execp->a_text;
+
+  /* Data.  */
+  data->filepos = pos;
+  if (!data->user_set_vma)
+    data->vma = 0;
+  vma = data->vma;
+
+  /* Since BSS follows data immediately, see if it needs alignment.  */
+  vma += data->size;
+  pad = align_power (vma, bss->alignment_power) - vma;
+  execp->a_data = data->size + pad;
+  pos += execp->a_data;
+
+  /* BSS.  */
+  if (!bss->user_set_vma)
+    bss->vma = vma;
+  else
+    vma = bss->vma;
+
+  /* Fix up exec header.  */
+  execp->a_bss = bss->size;
+  N_SET_MAGIC (execp, IMAGIC);
+}
+
 bfd_boolean
 NAME (aout, adjust_sizes_and_vmas) (bfd *abfd)
 {
@@ -1018,7 +1067,9 @@ NAME (aout, adjust_sizes_and_vmas) (bfd *abfd)
      I understand it better now, but I haven't time to do the cleanup this
      minute.  */
 
-  if (abfd->flags & WP_TEXT)
+  if (separate_i_d)
+    adata (abfd).magic = i_magic;
+  else if (abfd->flags & WP_TEXT)
     adata (abfd).magic = n_magic;
   else
     adata (abfd).magic = o_magic;
@@ -1031,6 +1082,7 @@ NAME (aout, adjust_sizes_and_vmas) (bfd *abfd)
 		{
 		case n_magic: str = "NMAGIC"; break;
 		case o_magic: str = "OMAGIC"; break;
+		case i_magic: str = "IMAGIC"; break;
 		case z_magic: str = "ZMAGIC"; break;
 		default: abort ();
 		}
@@ -1056,6 +1108,9 @@ NAME (aout, adjust_sizes_and_vmas) (bfd *abfd)
     case n_magic:
       adjust_n_magic (abfd, execp);
       break;
+    case i_magic:
+      adjust_i_magic (abfd, execp);
+      break;
     default:
       abort ();
     }
@@ -3624,6 +3679,7 @@ NAME (aout, final_link) (bfd *abfd,
   if (bfd_link_pic (info))
     abfd->flags |= DYNAMIC;
 
+  separate_i_d = info->separate_code;
   aout_info.info = info;
   aout_info.output_bfd = abfd;
   aout_info.contents = NULL;