* ld.h (check_nocrossrefs): Declare.

	* ldlang.h (struct lang_nocrossref): Define.
	(struct lang_nocrossrefs): Define.
	(nocrossref_list): Declare.
	(lang_add_nocrossref): Declare.
	* ldlex.l: Recognize NOCROSSREFS keyword.
	* ldgram.y (%union): Add nocrossref field.
	(NOCROSSREFS): New terminal.
	(ifile_p1): Recognize NOCROSSREFS.
	(nocrossref_list): New nonterminal.
	* ldlang.c (nocrossref_list): Define.
	(lang_add_nocrossref): New function.
	* ldmain.c (main): If nocrossref_list is not NULL, call
	check_nocrossrefs.
	(warning_callback): Free symbols if there is no place to store
	them.
	(notice): Call add_cref if nocrossref_list is not NULL.
	* ldcref.c: Include "ldexp.h" and "ldlang.h".
	(check_nocrossrefs): New function.
	(check_nocrossref): New static function.
	(struct check_refs_info): Define.
	(check_refs, check_reloc_refs): New static functions.
	* Makefile.in: Rebuild dependencies.
	* ld.texinfo (Option Commands): Document NOCROSSREFS.

9 files changed, 359 insertions, 10 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 6078513..706579f 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,5 +1,34 @@
 Thu Aug  1 12:52:19 1996  Ian Lance Taylor  <ian@cygnus.com>
 
+	* ld.h (check_nocrossrefs): Declare.
+	* ldlang.h (struct lang_nocrossref): Define.
+	(struct lang_nocrossrefs): Define.
+	(nocrossref_list): Declare.
+	(lang_add_nocrossref): Declare.
+	* ldlex.l: Recognize NOCROSSREFS keyword.
+	* ldgram.y (%union): Add nocrossref field.
+	(NOCROSSREFS): New terminal.
+	(ifile_p1): Recognize NOCROSSREFS.
+	(nocrossref_list): New nonterminal.
+	* ldlang.c (nocrossref_list): Define.
+	(lang_add_nocrossref): New function.
+	* ldmain.c (main): If nocrossref_list is not NULL, call
+	check_nocrossrefs.
+	(warning_callback): Free symbols if there is no place to store
+	them.
+	(notice): Call add_cref if nocrossref_list is not NULL.
+	* ldcref.c: Include "ldexp.h" and "ldlang.h".
+	(check_nocrossrefs): New function.
+	(check_nocrossref): New static function.
+	(struct check_refs_info): Define.
+	(check_refs, check_reloc_refs): New static functions.
+	* Makefile.in: Rebuild dependencies.
+	* ld.texinfo (Option Commands): Document NOCROSSREFS.
+
+	* ld.texinfo (Section Placement): Improve the wording of the
+	wildcard documentation.  Mention that wildcards are only searched
+	for on the command line, not in the file system.
+
 	* emultempl/sunos.em (gld${EMULATION_NAME}_after_open): Move
 	definition of lib_path inside condition where it is used.
 
diff --git a/ld/NEWS b/ld/NEWS
index 50cb355..ea11db2 100644
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -5,6 +5,8 @@ Changes since version 2.7:
 * Linker scripts may now contain shell wildcard characters for file and section
   names.
 
+* The NOCROSSREFS command was added to the linker script language.
+
 Changes since version 2.6:
 
 * New option --cref to print out a cross reference table.
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 1034b1e..99450f6 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -2704,6 +2704,24 @@ the environment variable @code{GNUTARGET}, if available, to select the
 output file format.  If that variable is also absent, @code{ld} uses
 the default format configured for your machine in the BFD libraries.
 @end ifclear
+
+@cindex cross references
+@kindex NOCROSSREFS ( @var{sections} )
+@item NOCROSSREFS ( @var{section} @var{section} @dots{} )
+This command may be used to tell @code{ld} to issue an error about any
+references among certain sections.
+
+In certain types of programs, particularly on embedded systems, when one
+section is loaded into memory, another section will not be.  Any direct
+references between the two sections would be errors.  For example, it
+would be an error if code in one section called a function defined in
+the other section.
+
+The @code{NOCROSSREFS} command takes a list of section names.  If
+@code{ld} detects any cross references between the sections, it reports
+an error and returns a non-zero exit status.  The @code{NOCROSSREFS}
+command uses output section names, defined in the @code{SECTIONS}
+command.  It does not use the names of input sections.
 @end table
 
 @ifset GENERIC
diff --git a/ld/ldcref.c b/ld/ldcref.c
index 2aceb1f..369cd62 100644
--- a/ld/ldcref.c
+++ b/ld/ldcref.c
@@ -18,7 +18,9 @@ You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
-/* This file holds routines that manage the cross reference table.  */
+/* This file holds routines that manage the cross reference table.
+   The table is used to generate cross reference reports.  It is also
+   used to implement the NOCROSSREFS command in the linker script.  */
 
 #include "bfd.h"
 #include "sysdep.h"
@@ -28,6 +30,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 #include "ld.h"
 #include "ldmain.h"
 #include "ldmisc.h"
+#include "ldexp.h"
+#include "ldlang.h"
 
 /* We keep an instance of this structure for each reference to a
    symbol from a given object.  */
@@ -71,6 +75,11 @@ static struct bfd_hash_entry *cref_hash_newfunc
 static boolean cref_fill_array PARAMS ((struct cref_hash_entry *, PTR));
 static int cref_sort_array PARAMS ((const PTR, const PTR));
 static void output_one_cref PARAMS ((FILE *, struct cref_hash_entry *));
+static boolean check_nocrossref PARAMS ((struct cref_hash_entry *, PTR));
+static void check_refs
+  PARAMS ((struct cref_hash_entry *, struct bfd_link_hash_entry *,
+	   struct lang_nocrossrefs *));
+static void check_reloc_refs PARAMS ((bfd *, asection *, PTR));
 
 /* Look up an entry in the cref hash table.  */
 
@@ -325,3 +334,212 @@ output_one_cref (fp, h)
 
   ASSERT (len == 0);
 }
+
+/* Check for prohibited cross references.  */
+
+void
+check_nocrossrefs ()
+{
+  if (! cref_initialized)
+    return;
+
+  cref_hash_traverse (&cref_table, check_nocrossref, (PTR) NULL);
+}
+
+/* Check one symbol to see if it is a prohibited cross reference.  */
+
+/*ARGSUSED*/
+static boolean
+check_nocrossref (h, ignore)
+     struct cref_hash_entry *h;
+     PTR ignore;
+{
+  struct bfd_link_hash_entry *hl;
+  asection *defsec;
+  const char *defsecname;
+  struct lang_nocrossrefs *ncrs;
+  struct lang_nocrossref *ncr;
+
+  hl = bfd_link_hash_lookup (link_info.hash, h->root.string, false,
+			     false, true);
+  if (hl == NULL)
+    {
+      einfo ("%P: symbol `%T' missing from main hash table\n",
+	     h->root.string);
+      return true;
+    }
+
+  if (hl->type != bfd_link_hash_defined
+      && hl->type != bfd_link_hash_defweak)
+    return true;
+
+  defsec = hl->u.def.section->output_section;
+  defsecname = bfd_get_section_name (defsec->owner, defsec);
+
+  for (ncrs = nocrossref_list; ncrs != NULL; ncrs = ncrs->next)
+    for (ncr = ncrs->list; ncr != NULL; ncr = ncr->next)
+      if (strcmp (ncr->name, defsecname) == 0)
+	check_refs (h, hl, ncrs);
+
+  return true;
+}
+
+/* The struct is used to pass information from check_refs to
+   check_reloc_refs through bfd_map_over_sections.  */
+
+struct check_refs_info
+{
+  struct cref_hash_entry *h;
+  asection *defsec;
+  struct lang_nocrossrefs *ncrs;
+  asymbol **asymbols;
+  boolean same;
+};
+
+/* This function is called for each symbol defined in a section which
+   prohibits cross references.  We need to look through all references
+   to this symbol, and ensure that the references are not from
+   prohibited sections.  */
+
+static void
+check_refs (h, hl, ncrs)
+     struct cref_hash_entry *h;
+     struct bfd_link_hash_entry *hl;
+     struct lang_nocrossrefs *ncrs;
+{
+  struct cref_ref *ref;
+
+  for (ref = h->refs; ref != NULL; ref = ref->next)
+    {
+      lang_input_statement_type *li;
+      asymbol **asymbols;
+      struct check_refs_info info;
+
+      /* We need to look through the relocations for this BFD, to see
+         if any of the relocations which refer to this symbol are from
+         a prohibited section.  Note that we need to do this even for
+         the BFD in which the symbol is defined, since even a single
+         BFD might contain a prohibited cross reference; for this
+         case, we set the SAME field in INFO, which will cause
+         CHECK_RELOCS_REFS to check for relocations against the
+         section as well as against the symbol.  */
+
+      li = (lang_input_statement_type *) ref->abfd->usrdata;
+      if (li != NULL && li->asymbols != NULL)
+	asymbols = li->asymbols;
+      else
+	{
+	  long symsize;
+	  long symbol_count;
+
+	  symsize = bfd_get_symtab_upper_bound (ref->abfd);
+	  if (symsize < 0)
+	    einfo ("%B%F: could not read symbols; %E\n", ref->abfd);
+	  asymbols = (asymbol **) xmalloc (symsize);
+	  symbol_count = bfd_canonicalize_symtab (ref->abfd, asymbols);
+	  if (symbol_count < 0)
+	    einfo ("%B%F: could not read symbols: %E\n", ref->abfd);
+	  if (li != NULL)
+	    {
+	      li->asymbols = asymbols;
+	      li->symbol_count = symbol_count;
+	    }
+	}
+
+      info.h = h;
+      info.defsec = hl->u.def.section;
+      info.ncrs = ncrs;
+      info.asymbols = asymbols;
+      if (ref->abfd == hl->u.def.section->owner)
+	info.same = true;
+      else
+	info.same = false;
+      bfd_map_over_sections (ref->abfd, check_reloc_refs, (PTR) &info);
+
+      if (li == NULL)
+	free (asymbols);
+    }
+}
+
+/* This is called via bfd_map_over_sections.  INFO->H is a symbol
+   defined in INFO->DEFSECNAME.  If this section maps into any of the
+   sections listed in INFO->NCRS, other than INFO->DEFSECNAME, then we
+   look through the relocations.  If any of the relocations are to
+   INFO->H, then we report a prohibited cross reference error.  */
+
+static void
+check_reloc_refs (abfd, sec, iarg)
+     bfd *abfd;
+     asection *sec;
+     PTR iarg;
+{
+  struct check_refs_info *info = (struct check_refs_info *) iarg;
+  asection *outsec;
+  const char *outsecname;
+  asection *outdefsec;
+  const char *outdefsecname;
+  struct lang_nocrossref *ncr;
+  const char *symname;
+  long relsize;
+  arelent **relpp;
+  long relcount;
+  arelent **p, **pend;
+
+  outsec = sec->output_section;
+  outsecname = bfd_get_section_name (outsec->owner, outsec);
+
+  outdefsec = info->defsec->output_section;
+  outdefsecname = bfd_get_section_name (outdefsec->owner, outdefsec);
+
+  /* The section where the symbol is defined is permitted.  */
+  if (strcmp (outsecname, outdefsecname) == 0)
+    return;
+
+  for (ncr = info->ncrs->list; ncr != NULL; ncr = ncr->next)
+    if (strcmp (outsecname, ncr->name) == 0)
+      break;
+
+  if (ncr == NULL)
+    return;
+
+  /* This section is one for which cross references are prohibited.
+     Look through the relocations, and see if any of them are to
+     INFO->H.  */
+
+  symname = info->h->root.string;
+
+  relsize = bfd_get_reloc_upper_bound (abfd, sec);
+  if (relsize < 0)
+    einfo ("%B%F: could not read relocs: %E\n", abfd);
+  if (relsize == 0)
+    return;
+
+  relpp = (arelent **) xmalloc (relsize);
+  relcount = bfd_canonicalize_reloc (abfd, sec, relpp, info->asymbols);
+  if (relcount < 0)
+    einfo ("%B%F: could not read relocs: %E\n", abfd);
+
+  p = relpp;
+  pend = p + relcount;
+  for (; p < pend && *p != NULL; p++)
+    {
+      arelent *q = *p;
+
+      if (q->sym_ptr_ptr != NULL
+	  && *q->sym_ptr_ptr != NULL
+	  && (strcmp (bfd_asymbol_name (*q->sym_ptr_ptr), symname) == 0
+	      || (info->same
+		  && *q->sym_ptr_ptr == info->defsec->symbol)))
+	{
+	  /* We found a reloc for the symbol.  The symbol is defined
+             in OUTSECNAME.  This reloc is from a section which is
+             mapped into a section from which references to OUTSECNAME
+             are prohibited.  We must report an error.  */
+	  einfo ("%X%C: prohibited cross reference from %s to `%T' in %s\n",
+		 abfd, sec, q->address, outsecname,
+		 bfd_asymbol_name (*q->sym_ptr_ptr), outdefsecname);
+	}
+    }
+
+  free (relpp);
+}
diff --git a/ld/ldgram.y b/ld/ldgram.y
index 92ba5bc..1f16baa 100644
--- a/ld/ldgram.y
+++ b/ld/ldgram.y
@@ -75,6 +75,7 @@ static int error_index;
       union etree_union *at;
       union etree_union *flags;
     } phdr;
+  struct lang_nocrossref *nocrossref;
 }
 
 %type <etree> exp opt_exp_with_type mustbe_exp opt_at phdr_type phdr_val
@@ -82,8 +83,9 @@ static int error_index;
 %type <name> memspec_opt casesymlist
 %token <integer> INT  
 %token <name> NAME LNAME
-%type  <integer> length
+%type <integer> length
 %type <phdr> phdr_qualifiers
+%type <nocrossref> nocrossref_list
 
 %right <token> PLUSEQ MINUSEQ MULTEQ DIVEQ  '=' LSHIFTEQ RSHIFTEQ   ANDEQ OREQ 
 %right <token> '?' ':'
@@ -112,7 +114,7 @@ static int error_index;
 %token NOLOAD DSECT COPY INFO OVERLAY
 %token NAME LNAME DEFINED TARGET_K SEARCH_DIR MAP ENTRY
 %token <integer> SIZEOF NEXT ADDR
-%token STARTUP HLL SYSLIB FLOAT NOFLOAT
+%token STARTUP HLL SYSLIB FLOAT NOFLOAT NOCROSSREFS
 %token ORIGIN FILL
 %token LENGTH CREATE_OBJECT_SYMBOLS INPUT GROUP OUTPUT CONSTRUCTORS
 %token ALIGNMOD AT PROVIDE
@@ -299,6 +301,10 @@ ifile_p1:
 		{ lang_add_map($3); }
 	|	INCLUDE filename 
 		{ ldfile_open_command_file($2); } ifile_list END
+	|	NOCROSSREFS '(' nocrossref_list ')'
+		{
+		  lang_add_nocrossref ($3);
+		}
 	;
 
 input_list:
@@ -569,6 +575,30 @@ floating_point_support:
 			{ lang_float(false); }
 	;
 		
+nocrossref_list:
+		/* empty */
+		{
+		  $$ = NULL;
+		}
+	|	NAME nocrossref_list
+		{
+		  struct lang_nocrossref *n;
+
+		  n = (struct lang_nocrossref *) xmalloc (sizeof *n);
+		  n->name = $1;
+		  n->next = $2;
+		  $$ = n;
+		}
+	|	NAME ',' nocrossref_list
+		{
+		  struct lang_nocrossref *n;
+
+		  n = (struct lang_nocrossref *) xmalloc (sizeof *n);
+		  n->name = $1;
+		  n->next = $3;
+		  $$ = n;
+		}
+	;
 
 mustbe_exp:		 { ldlex_expression(); }
 		exp
diff --git a/ld/ldlang.c b/ld/ldlang.c
index ae844be..b7a0493 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -142,6 +142,7 @@ boolean lang_has_input_file = false;
 boolean had_output_filename = false;
 boolean lang_float_flag = false;
 boolean delete_output_file_on_failure = false;
+struct lang_nocrossrefs *nocrossref_list;
 
 etree_type *base; /* Relocation base - or null */
 
@@ -3617,3 +3618,20 @@ lang_record_phdrs ()
 		 u->output_section_statement.name, pl->name);
     }
 }
+
+/* Record a list of sections which may not be cross referenced.  */
+
+void
+lang_add_nocrossref (l)
+     struct lang_nocrossref *l;
+{
+  struct lang_nocrossrefs *n;
+
+  n = (struct lang_nocrossrefs *) xmalloc (sizeof *n);
+  n->next = nocrossref_list;
+  n->list = l;
+  nocrossref_list = n;
+
+  /* Set notice_all so that we get informed about all symbols.  */
+  link_info.notice_all = true;
+}
diff --git a/ld/ldlang.h b/ld/ldlang.h
index 3d6a6f3..ee5b777 100644
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -1,5 +1,5 @@
 /* ldlang.h - linker command language support
-   Copyright 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+   Copyright 1991, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
    
    This file is part of GLD, the Gnu Linker.
    
@@ -96,6 +96,17 @@ typedef struct lang_output_statement_struct
   const char *name;
 } lang_output_statement_type;
 
+/* Section types specified in a linker script.  */
+
+enum section_type
+{
+  normal_section,
+  dsect_section,
+  copy_section,
+  noload_section,
+  info_section,
+  overlay_section
+};
 
 /* This structure holds a list of program headers describing segments
    in which this section should be placed.  */
@@ -120,7 +131,7 @@ typedef struct lang_output_section_statement_struct
     
   asection *bfd_section;
   int flags;			/* Or together of all input sections */
-  int loadable;			/* set from NOLOAD flag in script */
+  enum section_type sectype;
   struct memory_region_struct *region;
   size_t block_value;
   fill_type fill;
@@ -243,9 +254,6 @@ typedef struct lang_input_statement_struct
   /*    unsigned int globals_in_this_file;*/
   const char *target;
   boolean real;
-  asection *common_section;
-  asection *common_output_section;
-  boolean complained;
 } lang_input_statement_type;
 
 typedef struct
@@ -335,6 +343,25 @@ struct lang_phdr
   etree_type *flags;
 };
 
+/* This structure is used to hold a list of sections which may not
+   cross reference each other.  */
+
+struct lang_nocrossref
+{
+  struct lang_nocrossref *next;
+  const char *name;
+};
+
+/* The list of nocrossref lists.  */
+
+struct lang_nocrossrefs
+{
+  struct lang_nocrossrefs *next;
+  struct lang_nocrossref *list;
+};
+
+extern struct lang_nocrossrefs *nocrossref_list;
+
 extern lang_output_section_statement_type *abs_output_section;
 extern boolean lang_has_input_file;
 extern etree_type *base;
@@ -353,7 +380,7 @@ extern void lang_add_output PARAMS ((const char *, int from_script));
 extern void lang_enter_output_section_statement
   PARAMS ((const char *output_section_statement_name,
 	   etree_type * address_exp,
-	   int flags,
+	   enum section_type sectype,
 	   bfd_vma block_value,
 	   etree_type *align,
 	   etree_type *subalign,
@@ -431,5 +458,6 @@ extern void lang_new_phdr
   PARAMS ((const char *, etree_type *, boolean, boolean, etree_type *,
 	   etree_type *));
 extern void lang_section_in_phdr PARAMS ((const char *));
+extern void lang_add_nocrossref PARAMS ((struct lang_nocrossref *));
 
 #endif
diff --git a/ld/ldlex.l b/ld/ldlex.l
index 6c85f5a..796ff9d 100644
--- a/ld/ldlex.l
+++ b/ld/ldlex.l
@@ -256,6 +256,7 @@ NOCFILENAMECHAR	[_a-zA-Z0-9\/\.\-\_\+\$\:\[\]\\\~]
 <BOTH,SCRIPT>"SHORT"			{ RTOKEN( SHORT);}
 <BOTH,SCRIPT>"BYTE"			{ RTOKEN( BYTE);}
 <BOTH,SCRIPT>"NOFLOAT"		{ RTOKEN(NOFLOAT);}
+<BOTH,SCRIPT>"NOCROSSREFS"		{ RTOKEN(NOCROSSREFS);}
 <EXPRESSION,BOTH,SCRIPT>"NOLOAD"	{ RTOKEN(NOLOAD);}
 <EXPRESSION,BOTH,SCRIPT>"DSECT"		{ RTOKEN(DSECT);}
 <EXPRESSION,BOTH,SCRIPT>"COPY"		{ RTOKEN(COPY);}
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 3d0f9fa..315ac0c 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -323,6 +323,8 @@ main (argc, argv)
     lang_map ();
   if (command_line.cref)
     output_cref (config.map_file != NULL ? config.map_file : stdout);
+  if (nocrossref_list != NULL)
+    check_nocrossrefs ();
 
   /* Even if we're producing relocateable output, some non-fatal errors should
      be reported in the exit status.  (What non-fatal errors, if any, do we
@@ -1031,6 +1033,9 @@ warning_callback (info, warning, symbol, abfd, section, address)
 
       if (! info.found)
 	einfo ("%B: %s\n", abfd, warning);
+
+      if (entry == NULL)
+	free (asymbols);
     }
 
   return true;
@@ -1241,7 +1246,7 @@ notice (info, name, abfd, section, value)
 	   bfd_is_und_section (section) ? "reference to" : "definition of",
 	   name);
 
-  if (command_line.cref)
+  if (command_line.cref || nocrossref_list != NULL)
     add_cref (name, abfd, section, value);
 
   return true;