Re: Patch: Handle relative paths in .debug_line

[Bryce McKinlay <mckinlay@redhat.com>]

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Jim Blandy wrote:

>Bryce McKinlay <mckinlay@redhat.com> writes:
>
>  
>
>>Jim Blandy wrote:
>>
>>    
>>
>>>Thanks for this patch!
>>>
>>>In the revised dwarf2_start_subfile:
>>>
>>>- It looks to me as if the new code doesn't handle the case where both
>>> dirname and comp_dir are null.
>>>
>>>- It seems to me that, when fullname == filename, the loop over the
>>> subfiles duplicates the loop at the top of start_subfile.  So that
>>> loop should remain conditional.  Its comment should be moved and
>>> adjusted, too.
>>>
>>>
>>>      
>>>
>>Here's a revised patch that should address this. OK to commit?
>>    
>>
>
>Almost --- dwarf2_start_subfile still passes comp_dir to concat
>without checking whether it's NULL.
>  
>
Fixed in the following patch. OK?

Bryce


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2004-07-29  Bryce McKinlay  <mckinlay@redhat.com>

	* dwarf2read.c (dwarf_decode_lines): Pass comp_dir to
	dwarf2_start_subfile.
	(dwarf2_start_subfile): New comp_dir parameter.	Handle relative paths
	in .debug_line by appending them to comp_dir. Use make_cleanup to
	free strings used in directory concatenation.

Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.156
diff -u -r1.156 dwarf2read.c
--- dwarf2read.c	6 Jul 2004 19:29:30 -0000	1.156
+++ dwarf2read.c	29 Jul 2004 20:52:10 -0000
@@ -762,7 +762,7 @@
 static void dwarf_decode_lines (struct line_header *, char *, bfd *,
 				struct dwarf2_cu *, struct partial_symtab *);
 
-static void dwarf2_start_subfile (char *, char *);
+static void dwarf2_start_subfile (char *, char *, char *);
 
 static struct symbol *new_symbol (struct die_info *, struct type *,
 				  struct dwarf2_cu *);
@@ -5951,12 +5951,10 @@
 	     directory and file name numbers in the statement program
 	     are 1-based.  */
           struct file_entry *fe = &lh->file_names[file - 1];
-          char *dir;
+          char *dir = NULL;
           if (fe->dir_index)
             dir = lh->include_dirs[fe->dir_index - 1];
-          else
-            dir = comp_dir;
-	  dwarf2_start_subfile (fe->name, dir);
+	  dwarf2_start_subfile (fe->name, dir, comp_dir);
 	}
 
       /* Decode the table. */
@@ -6044,17 +6042,15 @@
                    but the directory and file name numbers in the
                    statement program are 1-based.  */
                 struct file_entry *fe;
-                char *dir;
+                char *dir = NULL;
                 file = read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
                 line_ptr += bytes_read;
                 fe = &lh->file_names[file - 1];
                 fe->included_p = 1;
                 if (fe->dir_index)
                   dir = lh->include_dirs[fe->dir_index - 1];
-                else
-                  dir = comp_dir;
                 if (!decode_for_pst_p)
-                  dwarf2_start_subfile (fe->name, dir);
+                  dwarf2_start_subfile (fe->name, dir, comp_dir);
               }
 	      break;
 	    case DW_LNS_set_column:
@@ -6112,7 +6108,8 @@
 
 /* Start a subfile for DWARF.  FILENAME is the name of the file and
    DIRNAME the name of the source directory which contains FILENAME
-   or NULL if not known.
+   or NULL if not known.  COMP_DIR is the value of DW_AT_comp_dir.  If
+   DIRNAME specifies a relative path, it is appended to COMP_DIR.
    This routine tries to keep line numbers from identical absolute and
    relative file names in a common subfile.
 
@@ -6131,8 +6128,19 @@
    subfile, so that `break /srcdir/list0.c:1' works as expected.  */
 
 static void
-dwarf2_start_subfile (char *filename, char *dirname)
+dwarf2_start_subfile (char *filename, char *dirname, char *comp_dir)
 {
+  struct cleanup *back_to = make_cleanup (null_cleanup, 0);
+
+  /* If we have a relative dirname, append it to comp_dir.  */
+  if (comp_dir != NULL && dirname != NULL && !IS_ABSOLUTE_PATH (dirname))
+    {
+      dirname = concat (comp_dir, "/", dirname, NULL);
+      make_cleanup (xfree, dirname);
+    }
+  else if (dirname == NULL)
+    dirname = comp_dir;
+
   /* If the filename isn't absolute, try to match an existing subfile
      with the full pathname.  */
 
@@ -6140,19 +6148,20 @@
     {
       struct subfile *subfile;
       char *fullname = concat (dirname, "/", filename, NULL);
+      make_cleanup (xfree, fullname);
 
       for (subfile = subfiles; subfile; subfile = subfile->next)
 	{
 	  if (FILENAME_CMP (subfile->name, fullname) == 0)
 	    {
 	      current_subfile = subfile;
-	      xfree (fullname);
+	      do_cleanups (back_to);
 	      return;
 	    }
 	}
-      xfree (fullname);
     }
   start_subfile (filename, dirname);
+  do_cleanups (back_to);
 }
 
 static void