Re: [RFA] Show some tips when file cmd get bfd_error_file_ambiguously_recognized

[Hui Zhu <teawater@gmail.com>]

Thanks guys.  I make a new patch according to your mails.

And about the xrealloc, I don't know what I was thinking when I use
it.  It is really bad, ugly and wasted me a lot of time.  :(

Please help me review the new patch.  Thanks.

Best regards,
Hui

2010-01-29  Hui Zhu  <teawater@gmail.com>

	* defs.h (gdb_bfd_errmsg): New extern.
	* exec.c (exec_file_attach): Change bfd_errmsg to
	gdb_bfd_errmsg.
	* utils.c (AMBIGUOUS_MESS1): New macro.
	(AMBIGUOUS_MESS2): New macro.
	(gdb_bfd_errmsg): New function.

---
 defs.h  |    8 ++++++++
 exec.c  |    6 ++++--
 utils.c |   40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 2 deletions(-)

--- a/defs.h
+++ b/defs.h
@@ -419,6 +419,13 @@ char **gdb_buildargv (const char *);

 int compare_positive_ints (const void *ap, const void *bp);

+/* A wrapper for bfd_errmsg to produce a more helpful error message
+   in the case of bfd_error_file_ambiguously recognized.
+   MATCHING, if non-NULL, is the corresponding argument to
+   bfd_check_format_matches, and will be freed.  */
+
+extern const char *gdb_bfd_errmsg (bfd_error_type error_tag, char **matching);
+
 /* From demangle.c */

 extern void set_demangling_style (char *);
@@ -1226,4 +1233,5 @@ void dummy_obstack_deallocate (void *obj
 extern void initialize_progspace (void);
 extern void initialize_inferiors (void);

+
 #endif /* #ifndef DEFS_H */
--- a/exec.c
+++ b/exec.c
@@ -219,6 +219,7 @@ exec_file_attach (char *filename, int fr
       char *scratch_pathname;
       int scratch_chan;
       struct target_section *sections = NULL, *sections_end = NULL;
+      char **matching;

       scratch_chan = openp (getenv ("PATH"), OPF_TRY_CWD_FIRST, filename,
 		   write_files ? O_RDWR | O_BINARY : O_RDONLY | O_BINARY,
@@ -253,13 +254,14 @@ exec_file_attach (char *filename, int fr
       scratch_pathname = xstrdup (scratch_pathname);
       cleanups = make_cleanup (xfree, scratch_pathname);

-      if (!bfd_check_format (exec_bfd, bfd_object))
+      if (!bfd_check_format_matches (exec_bfd, bfd_object, &matching))
 	{
 	  /* Make sure to close exec_bfd, or else "run" might try to use
 	     it.  */
 	  exec_close ();
 	  error (_("\"%s\": not in executable format: %s"),
-		 scratch_pathname, bfd_errmsg (bfd_get_error ()));
+		 scratch_pathname,
+		 gdb_bfd_errmsg (bfd_get_error (), matching));
 	}

       /* FIXME - This should only be run for RS6000, but the ifdef is a poor
--- a/utils.c
+++ b/utils.c
@@ -3608,6 +3608,46 @@ compare_positive_ints (const void *ap, c
   return * (int *) ap - * (int *) bp;
 }

+#define AMBIGUOUS_MESS1	".\nMatching formats:"
+#define AMBIGUOUS_MESS2	".\nUse \"set gnutarget format-name\" specify
the format."
+
+const char *
+gdb_bfd_errmsg (bfd_error_type error_tag, char **matching)
+{
+  char *ret, *retp;
+  int ret_len;
+  char **p;
+
+  /* Check if errmsg just need simple return.  */
+  if (error_tag != bfd_error_file_ambiguously_recognized || matching == NULL)
+    return bfd_errmsg (error_tag);
+
+  ret_len = strlen (bfd_errmsg (error_tag)) + strlen (AMBIGUOUS_MESS1)
+            + strlen (AMBIGUOUS_MESS2);
+  for (p = matching; *p; p++)
+    ret_len += strlen (*p) + 1;
+  ret = xmalloc (ret_len + 1);
+  retp = ret;
+  make_cleanup (xfree, ret);
+
+  strcpy (retp, bfd_errmsg (error_tag));
+  retp += strlen (retp);
+
+  strcpy (retp, AMBIGUOUS_MESS1);
+  retp += strlen (retp);
+
+  for (p = matching; *p; p++)
+    {
+      sprintf (retp, " %s", *p);
+      retp += strlen (retp);
+    }
+  xfree (matching);
+
+  strcpy (retp, AMBIGUOUS_MESS2);
+
+  return ret;
+}
+
 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern initialize_file_ftype _initialize_utils;