Reinstate various pieces backed out from smart_rename changes

In the interests of a stable release various last minute smart_rename
patches were backed out of the 2.36 branch.  The main reason to
reinstate some of those backed out changes here is to make necessary
followup fixes to commit 8e03235147 simple cherry-picks from
mainline.  A secondary reason is that ar -M support isn't fixed for
pr26945 without this patch.

	PR 26945
	* ar.c: Don't include libbfd.h.
	(write_archive): Replace xmalloc+strcpy with xstrdup.
	* arsup.c (temp_name, real_ofd): New static variables.
	(ar_open): Use make_tempname and bfd_fdopenw.
	(ar_save): Adjust to suit ar_open changes.
	* objcopy.c: Don't include libbfd.h.
	* rename.c: Rename and reorder variables.

(cherry picked from commit 95b91a043a)

binutils/ChangeLog

@@ -1,3 +1,16 @@
+2021-02-26  Alan Modra  <amodra@gmail.com>
+
+	Backport from mainline
+	2021-02-03  Alan Modra  <amodra@gmail.com>
+	PR 26945
+	* ar.c: Don't include libbfd.h.
+	(write_archive): Replace xmalloc+strcpy with xstrdup.
+	* arsup.c (temp_name, real_ofd): New static variables.
+	(ar_open): Use make_tempname and bfd_fdopenw.
+	(ar_save): Adjust to suit ar_open changes.
+	* objcopy.c: Don't include libbfd.h.
+	* rename.c: Rename and reorder variables.
+
 2021-02-22  Siddhesh Poyarekar  <siddhesh@gotplt.org>
 
 	* ar.c (write_archive): Adjust call to SMART_RENAME.

binutils/ar.c

@@ -25,7 +25,6 @@
 
 #include "sysdep.h"
 #include "bfd.h"
-#include "libbfd.h"
 #include "libiberty.h"
 #include "progress.h"
 #include "getopt.h"
@@ -1255,8 +1254,7 @@ write_archive (bfd *iarch)
   bfd *contents_head = iarch->archive_next;
   int ofd = -1;
 
-  old_name = (char *) xmalloc (strlen (bfd_get_filename (iarch)) + 1);
-  strcpy (old_name, bfd_get_filename (iarch));
+  old_name = xstrdup (bfd_get_filename (iarch));
   new_name = make_tempname (old_name, &ofd);
 
   if (new_name == NULL)

binutils/arsup.c

@@ -42,6 +42,8 @@ extern int deterministic;
 
 static bfd *obfd;
 static char *real_name;
+static char *temp_name;
+static int real_ofd;
 static FILE *outfile;
 
 static void
@@ -149,27 +151,24 @@ maybequit (void)
 void
 ar_open (char *name, int t)
 {
-  char *tname;
-  const char *bname = lbasename (name);
-  real_name = name;
+  real_name = xstrdup (name);
+  temp_name = make_tempname (real_name, &real_ofd);
 
-  /* Prepend tmp- to the beginning, to avoid file-name clashes after
-     truncation on filesystems with limited namespaces (DOS).  */
-  if (asprintf (&tname, "%.*stmp-%s", (int) (bname - name), name, bname) == -1)
+  if (temp_name == NULL)
     {
-      fprintf (stderr, _("%s: Can't allocate memory for temp name (%s)\n"),
+      fprintf (stderr, _("%s: Can't open temporary file (%s)\n"),
 	       program_name, strerror(errno));
       maybequit ();
       return;
     }
 
-  obfd = bfd_openw (tname, NULL);
+  obfd = bfd_fdopenw (temp_name, NULL, real_ofd);
 
   if (!obfd)
     {
       fprintf (stderr,
 	       _("%s: Can't open output archive %s\n"),
-	       program_name,  tname);
+	       program_name, temp_name);
 
       maybequit ();
     }
@@ -344,16 +343,30 @@ ar_save (void)
     }
   else
     {
-      char *ofilename = xstrdup (bfd_get_filename (obfd));
+      struct stat target_stat;
 
       if (deterministic > 0)
         obfd->flags |= BFD_DETERMINISTIC_OUTPUT;
 
       bfd_close (obfd);
 
-      smart_rename (ofilename, real_name, NULL);
+      if (stat (real_name, &target_stat) != 0)
+	{
+	  /* The temp file created in ar_open has mode 0600 as per mkstemp.
+	     Create the real empty output file here so smart_rename will
+	     update the mode according to the process umask.  */
+	  obfd = bfd_openw (real_name, NULL);
+	  if (obfd != NULL)
+	    {
+	      bfd_set_format (obfd, bfd_archive);
+	      bfd_close (obfd);
+	    }
+	}
+
+      smart_rename (temp_name, real_name, NULL);
       obfd = 0;
-      free (ofilename);
+      free (temp_name);
+      free (real_name);
     }
 }
 

binutils/objcopy.c

@@ -20,7 +20,6 @@
 
 #include "sysdep.h"
 #include "bfd.h"
-#include "libbfd.h"
 #include "progress.h"
 #include "getopt.h"
 #include "libiberty.h"

binutils/rename.c

@@ -130,11 +130,11 @@ int
 smart_rename (const char *from, const char *to,
 	      struct stat *target_stat ATTRIBUTE_UNUSED)
 {
-  bfd_boolean exists;
-  struct stat s;
   int ret = 0;
+  struct stat to_stat;
+  bfd_boolean exists;
 
-  exists = lstat (to, &s) == 0;
+  exists = lstat (to, &to_stat) == 0;
 
 #if defined (_WIN32) && !defined (__CYGWIN32__)
   /* Win32, unlike unix, will not erase `to' in `rename(from, to)' but