Add new NOCROSSREFS_TO linker script command

NOCROSSREFS_TO is similar to the existing NOCROSSREFS command but only
checks one direction of cross referencing.

ld/ChangeLog

	* ld.texinfo: Document NOCROSSREFS_TO script command.
	* ldlang.h (struct lang_nocrossrefs): Add onlyfirst field.
	(lang_add_nocrossref_to): New prototype.
	* ldcref.c (check_local_sym_xref): Use onlyfirst to only look for
	symbols defined in the first section.
	(check_nocrossref): Likewise.
	* ldgram.y (NOCROSSREFS_TO): New script command.
	* ldlang.c (lang_add_nocrossref): Set onlyfirst to FALSE.
	(lang_add_nocrossref_to): New function.
	* ldlex.l (NOCROSSREFS_TO): New token.
	* NEWS: Mention NOCROSSREFS_TO.
	* testsuite/ld-scripts/cross4.t: New file.
	* testsuite/ld-scripts/cross5.t: Likewise.
	* testsuite/ld-scripts/cross6.t: Likewise.
	* testsuite/ld-scripts/cross7.t: Likewise.
	* testsuite/ld-scripts/crossref.exp: Run 4 new NOCROSSREFS_TO
	tests.

1 files changed, 10 insertions, 0 deletions

diff --git a/ld/ldlang.c b/ld/ldlang.c
index 1947efc..856e3e2 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -7486,11 +7486,21 @@ lang_add_nocrossref (lang_nocrossref_type *l)
   n = (struct lang_nocrossrefs *) xmalloc (sizeof *n);
   n->next = nocrossref_list;
   n->list = l;
+  n->onlyfirst = FALSE;
   nocrossref_list = n;
 
   /* Set notice_all so that we get informed about all symbols.  */
   link_info.notice_all = TRUE;
 }
+
+/* Record a section that cannot be referenced from a list of sections.  */
+
+void
+lang_add_nocrossref_to (lang_nocrossref_type *l)
+{
+  lang_add_nocrossref (l);
+  nocrossref_list->onlyfirst = TRUE;
+}
 
 /* Overlay handling.  We handle overlays with some static variables.  */