Re: [PATCH/RFC] ld checks for input/output file conflicts

[Elias Athanasopoulos <eathan at otenet dot gr>]

On Sat, Oct 05, 2002 at 02:06:31PM -0400, Daniel Jacobowitz wrote:
> Duplications?  I'm not sure you can disallow them.  For instance, do ar
> archives go through that routine?  If so, you broke GCC - -lgcc -c
> -lgcc.
> 
> The other bit I like.

OK.

ld/ChangeLog

2002-10-05  Elias Athanasopoulos  <eathan@otenet.gr>

	* ldlang.c (lang_file_exist): New function.
	(new_afile): Abort if the filename to be added matches the linker 
	output filename.
	* ldlang.h: Add prototype for lang_file_exist.
	* lexsup.c (parse_args): Abort if the output filename matches
	one of the input filenames.

--- ldlang.c.orig	Fri Oct  4 19:15:58 2002
+++ ldlang.c	Sun Oct  6 03:18:44 2002
@@ -476,6 +476,27 @@ new_statement (type, size, list)
   return new;
 }
 
+/* Check if a file exist in the input_file_chain list */
+
+boolean
+lang_file_exist (name)
+    const char *name;
+{
+  lang_input_statement_type *p;
+    
+  for (p = (lang_input_statement_type *) input_file_chain.head;
+      p != (lang_input_statement_type *) NULL;
+      p = (lang_input_statement_type *) p->next_real_file)
+    {
+      if (p->filename != (char *) NULL
+          && name != (char *) NULL
+          && strcmp (p->filename, name) == 0)
+            return 1;
+    }
+
+    return 0;
+}
+
 /* Build a new input file node for the language.  There are several
    ways in which we treat an input file, eg, we only look at symbols,
    or prefix it with a -l etc.
@@ -493,7 +514,14 @@ new_afile (name, file_type, target, add_
      boolean add_to_list;
 {
   lang_input_statement_type *p;
-
+  
+  /* We abort if the input file is identical with the output. */
+  if (name != NULL && output_filename != NULL && !strcmp (name, output_filename))
+    {
+      einfo ("%P%F: input file %s has been used as output. Aborting.\n", name);
+      xexit (1);
+    } 
+  
   if (add_to_list)
     p = new_stat (lang_input_statement, stat_ptr);
   else


--- ldlang.h.orig	Fri Oct  4 19:14:05 2002
+++ ldlang.h	Fri Oct  4 20:37:50 2002
@@ -483,5 +483,6 @@ extern void lang_register_vers_node
 	   struct bfd_elf_version_deps *));
 boolean unique_section_p PARAMS ((const char *));
 extern void lang_add_unique PARAMS ((const char *));
+extern boolean lang_file_exist PARAMS ((const char *));
 
 #endif


--- lexsup.c.orig	Fri Oct  4 18:54:41 2002
+++ lexsup.c	Sat Oct  5 19:43:53 2002
@@ -796,7 +796,12 @@ parse_args (argc, argv)
 	  link_info.optimize = strtoul (optarg, NULL, 0) ? true : false;
 	  break;
 	case 'o':
-	  lang_add_output (optarg, 0);
+          if (lang_file_exist (optarg))
+            {
+              einfo ("%P%F: output file %s has been used as input. Aborting.\n", optarg);
+              xexit (1);
+            }
+          lang_add_output (optarg, 0);
 	  break;
 	case OPTION_OFORMAT:
 	  lang_add_output_format (optarg, (char *) NULL, (char *) NULL, 0);