[rfc] [05/18] Cell multi-arch: Non-file-backed shared library BFD infrastructure

["Ulrich Weigand" <uweigand at de dot ibm dot com>]

Hello,

as a minor infrastructure extension, this patch allows a solib implementation
to provide BFDs to access a shared library that is not found in the file
system.  This is used by the Cell debugger to retrieve embedded SPU executable
images from inferior memory.

Bye,
Ulrich


ChangeLog:

	* solib.h (struct target_so_ops): New member open_bfd.
	* solib.c (solib_map_sections): Use open_bfd callback if present.
	(symbol_add_stub): Likewise.


Index: src/gdb/solib.c
===================================================================
--- src.orig/gdb/solib.c
+++ src/gdb/solib.c
@@ -311,15 +311,22 @@ static int
 solib_map_sections (void *arg)
 {
   struct so_list *so = (struct so_list *) arg;	/* catch_errors bogon */
+  struct target_so_ops *ops = solib_ops (target_gdbarch);
   char *filename;
   struct section_table *p;
   struct cleanup *old_chain;
-  bfd *abfd;
+  bfd *abfd = NULL;
+
+  if (ops->open_bfd)
+    abfd = ops->open_bfd (so->so_name);
 
-  filename = tilde_expand (so->so_name);
-  old_chain = make_cleanup (xfree, filename);
-  abfd = solib_bfd_open (filename);
-  do_cleanups (old_chain);
+  if (!abfd)
+    {
+      filename = tilde_expand (so->so_name);
+      old_chain = make_cleanup (xfree, filename);
+      abfd = solib_bfd_open (filename);
+      do_cleanups (old_chain);
+    }
 
   /* Leave bfd open, core_xfer_memory and "info files" need it.  */
   so->abfd = abfd;
@@ -338,8 +345,6 @@ solib_map_sections (void *arg)
 
   for (p = so->sections; p < so->sections_end; p++)
     {
-      struct target_so_ops *ops = solib_ops (target_gdbarch);
-
       /* Relocate the section binding addresses as recorded in the shared
          object's file by the base address to which the object was actually
          mapped. */
@@ -420,7 +425,9 @@ static int
 symbol_add_stub (void *arg)
 {
   struct so_list *so = (struct so_list *) arg;  /* catch_errs bogon */
+  struct target_so_ops *ops = solib_ops (target_gdbarch);
   struct section_addr_info *sap;
+  bfd *abfd = NULL;
 
   /* Have we already loaded this shared object?  */
   ALL_OBJFILES (so->objfile)
@@ -429,11 +436,18 @@ symbol_add_stub (void *arg)
 	return 1;
     }
 
+  /* Open a second BFD for this file.  */
+  if (ops->open_bfd)
+    abfd = ops->open_bfd (so->so_name);
+
+  if (!abfd)
+    abfd = symfile_bfd_open (so->so_name);
+
   sap = build_section_addr_info_from_section_table (so->sections,
                                                     so->sections_end);
 
-  so->objfile = symbol_file_add (so->so_name, so->from_tty,
-				 sap, 0, OBJF_SHARED);
+  so->objfile = symbol_file_add_from_bfd (abfd, so->from_tty,
+					  sap, 0, OBJF_SHARED);
   free_section_addr_info (sap);
 
   return (1);
Index: src/gdb/solist.h
===================================================================
--- src.orig/gdb/solist.h
+++ src/gdb/solist.h
@@ -118,6 +118,10 @@ struct target_so_ops
        and another from the list returned by current_sos, return 1
        if they represent the same library.  */
     int (*same) (struct so_list *gdb, struct so_list *inferior);
+
+    /* Extra hook for opening a BFD for a solib.  Can be used to
+       retrieve solibs from inferior memory instead of from files.  */
+    bfd *(*open_bfd) (char *pathname);
   };
 
 /* Free the memory associated with a (so_list *).  */
-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com