[PATCH 1/2] Add -B support to gcc-ar/ranlib/nm

[Andi Kleen <andi at firstfloor dot org>]

From: Andi Kleen <ak@linux.intel.com>

To use gcc-{ar,ranlib} for boot strap we need to add a -B option
to the tool. Since ar has weird and unusual argument conventions
implement the code by hand instead of using any libraries.

v2: Fix typo
v3: Improve comments. Use strlen. Use DIR_SEPARATOR. Add prefixes at
begin.

gcc/:

2014-08-31  Andi Kleen  <ak@linux.intel.com>

	* file-find.c (add_prefix_begin): Add.
	(do_add_prefix): Rename from add_prefix with first argument.
	(add_prefix): Add new wrapper.
	* file-find.h (add_prefix_begin): Add.
	* gcc-ar.c (main): Support -B option.
---
 gcc/file-find.c | 23 ++++++++++++++++++++---
 gcc/file-find.h |  1 +
 gcc/gcc-ar.c    | 43 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 3 deletions(-)

diff --git a/gcc/file-find.c b/gcc/file-find.c
index 87d486d..be608b2 100644
--- a/gcc/file-find.c
+++ b/gcc/file-find.c
@@ -105,15 +105,16 @@ find_a_file (struct path_prefix *pprefix, const char *name, int mode)
   return 0;
 }
 
-/* Add an entry for PREFIX to prefix list PPREFIX.  */
+/* Add an entry for PREFIX to prefix list PREFIX.
+   Add at beginning if FIRST is true.  */
 
 void
-add_prefix (struct path_prefix *pprefix, const char *prefix)
+do_add_prefix (struct path_prefix *pprefix, const char *prefix, bool first)
 {
   struct prefix_list *pl, **prev;
   int len;
 
-  if (pprefix->plist)
+  if (pprefix->plist && !first)
     {
       for (pl = pprefix->plist; pl->next; pl = pl->next)
 	;
@@ -138,6 +139,22 @@ add_prefix (struct path_prefix *pprefix, const char *prefix)
   *prev = pl;
 }
 
+/* Add an entry for PREFIX at the end of prefix list PREFIX.  */
+
+void
+add_prefix (struct path_prefix *pprefix, const char *prefix)
+{
+  do_add_prefix (pprefix, prefix, false);
+}
+
+/* Add an entry for PREFIX at the begin of prefix list PREFIX.  */
+
+void
+add_prefix_begin (struct path_prefix *pprefix, const char *prefix)
+{
+  do_add_prefix (pprefix, prefix, true);
+}
+
 /* Take the value of the environment variable ENV, break it into a path, and
    add of the entries to PPREFIX.  */
 
diff --git a/gcc/file-find.h b/gcc/file-find.h
index b438056..0754d99 100644
--- a/gcc/file-find.h
+++ b/gcc/file-find.h
@@ -40,6 +40,7 @@ struct path_prefix
 extern void find_file_set_debug (bool);
 extern char *find_a_file (struct path_prefix *, const char *, int);
 extern void add_prefix (struct path_prefix *, const char *);
+extern void add_prefix_begin (struct path_prefix *, const char *);
 extern void prefix_from_env (const char *, struct path_prefix *);
 extern void prefix_from_string (const char *, struct path_prefix *);
 
diff --git a/gcc/gcc-ar.c b/gcc/gcc-ar.c
index aebaa92..b5199e6 100644
--- a/gcc/gcc-ar.c
+++ b/gcc/gcc-ar.c
@@ -132,9 +132,52 @@ main (int ac, char **av)
   const char **nargv;
   bool is_ar = !strcmp (PERSONALITY, "ar");
   int exit_code = FATAL_EXIT_CODE;
+  int i;
 
   setup_prefixes (av[0]);
 
+  /* Not using getopt for now.  */
+  for (i = 0; i < ac; i++)
+      if (!strncmp (av[i], "-B", 2))
+	{
+	  const char *arg = av[i] + 2;
+	  const char *end;
+	  size_t len;
+
+	  memmove (av + i, av + i + 1, sizeof (char *) * ((ac + 1) - i));
+	  ac--;
+	  if (*arg == 0)
+	    {
+	      arg = av[i + 1];
+	      if (!arg)
+		{
+		  fprintf (stderr, "Usage: gcc-ar [-B prefix] ar arguments ...\n");
+		  exit (EXIT_FAILURE);
+		}
+	      memmove (av + i, av + i + 1, sizeof (char *) * ((ac + 1) - i));
+	      ac--;
+	      i++;
+	    }
+	  /* else it's a joined argument  */
+
+	  len = strlen (arg);
+	  if (len > 0)
+		  len--;
+	  end = arg + len;
+
+	  /* Always add a dir separator for the prefix list.  */
+	  if (end > arg && !IS_DIR_SEPARATOR (*end))
+	    {
+	      static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
+	      arg = concat (arg, dir_separator_str, NULL);
+	    }
+
+	  add_prefix_begin (&path, arg);
+	  add_prefix_begin (&target_path, arg);
+	  break;
+	}
+
+
   /* Find the GCC LTO plugin */
   plugin = find_a_file (&target_path, LTOPLUGINSONAME, R_OK);
   if (!plugin)
-- 
2.0.4