solib.c relocation improvements

gdb/ChangeLog

@@ -1,3 +1,29 @@
+2000-10-30  Kevin Buettner  <kevinb@redhat.com>
+
+	Changes based on analysis from Peter Schauer:
+	* solist.h (struct so_list): Remove field lmend.
+	(struct target_so_ops): Remove field lm_addr.  Add field
+	relocate_section_addresses.  Add comments for all fields
+	in this structure
+	(TARGET_SO_LM_ADDR): Remove.
+	(TARGET_SO_RELOCATE_SECTION_ADDRESSES): New macro.
+	* solib-svr4.c (svr4_relocate_section_addresses): New function.
+	(_initialize_svr4_solib): Remove lm_addr initialization.  Add
+	initialization for relocate_section_addresses.
+	* solib.c (solib_map_sections): Invoke 
+	TARGET_SO_RELOCATE_SECTION_ADDRESSES instead of using now
+	defunct TARGET_SO_LM_ADDR to relocate the section addresses.
+	Also, eliminate assignment to the lmend field since this
+	field no longer exists.
+	(symbol_add_stub): Remove machinery for determining the lowest
+	section.
+	(info_sharedlibrary_command): Print the text section starting
+	and ending addresses.
+	(solib_address): Don't use TARGET_SO_LM_ADDR, nor so->lmend to
+	determine if an address is in a shared object.  Instead, scan
+	the section table and test against the starting and ending
+	addresses for each section.
+
 2000-10-30  Michael Snyder  <msnyder@cleaver.cygnus.com>
 
 	* config/m68k/linux.mh: Remove solib.c, solib-svr4.c from NATDEPFILES.

gdb/solib-svr4.c

@@ -1567,12 +1567,20 @@ svr4_free_so (struct so_list *so)
   free (so->lm_info);
 }
 
+static void
+svr4_relocate_section_addresses (struct so_list *so,
+                                 struct section_table *sec)
+{
+  sec->addr += LM_ADDR (so);
+  sec->endaddr += LM_ADDR (so);
+}
+
 static struct target_so_ops svr4_so_ops;
 
 void
 _initialize_svr4_solib (void)
 {
-  svr4_so_ops.lm_addr = LM_ADDR;
+  svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses;
   svr4_so_ops.free_so = svr4_free_so;
   svr4_so_ops.clear_solib = svr4_clear_solib;
   svr4_so_ops.solib_create_inferior_hook = svr4_solib_create_inferior_hook;

gdb/solib.c

@@ -180,9 +180,7 @@ solib_map_sections (PTR arg)
       /* Relocate the section binding addresses as recorded in the shared
          object's file by the base address to which the object was actually
          mapped. */
-      p->addr += TARGET_SO_LM_ADDR (so);
-      p->endaddr += TARGET_SO_LM_ADDR (so);
-      so->lmend = max (p->endaddr, so->lmend);
+      TARGET_SO_RELOCATE_SECTION_ADDRESSES (so, p);
       if (STREQ (p->the_bfd_section->name, ".text"))
 	{
 	  so->textsection = p;
@@ -248,9 +246,6 @@ symbol_add_stub (PTR arg)
 {
   register struct so_list *so = (struct so_list *) arg;  /* catch_errs bogon */
   struct section_addr_info *sap;
-  CORE_ADDR lowest_addr = 0;
-  int lowest_index;
-  asection *lowest_sect = NULL;
 
   /* Have we already loaded this shared object?  */
   ALL_OBJFILES (so->objfile)
@@ -259,35 +254,9 @@ symbol_add_stub (PTR arg)
 	return 1;
     }
 
-  /* Find the shared object's text segment.  */
-  if (so->textsection)
-    {
-      lowest_addr = so->textsection->addr;
-      lowest_sect = bfd_get_section_by_name (so->abfd, ".text");
-      lowest_index = lowest_sect->index;
-    }
-  else if (so->abfd != NULL)
-    {
-      /* If we didn't find a mapped non zero sized .text section, set
-         up lowest_addr so that the relocation in symbol_file_add does
-         no harm.  */
-      lowest_sect = bfd_get_section_by_name (so->abfd, ".text");
-      if (lowest_sect == NULL)
-	bfd_map_over_sections (so->abfd, find_lowest_section,
-			       (PTR) &lowest_sect);
-      if (lowest_sect)
-	{
-	  lowest_addr = bfd_section_vma (so->abfd, lowest_sect)
-	    + TARGET_SO_LM_ADDR (so);
-	  lowest_index = lowest_sect->index;
-	}
-    }
-
   sap = build_section_addr_info_from_section_table (so->sections,
                                                     so->sections_end);
 
-  sap->other[lowest_index].addr = lowest_addr;
-
   so->objfile = symbol_file_add (so->so_name, so->from_tty,
 				 sap, 0, OBJF_SHARED);
   free_section_addr_info (sap);
@@ -610,12 +579,17 @@ info_sharedlibrary_command (char *ignore, int from_tty)
 	    }
 
 	  printf_unfiltered ("%-*s", addr_width,
-                             local_hex_string_custom (
-			       (unsigned long) TARGET_SO_LM_ADDR (so),
-	                       addr_fmt));
+			     so->textsection != NULL 
+			       ? local_hex_string_custom (
+			           (unsigned long) so->textsection->addr,
+	                           addr_fmt)
+			       : "");
 	  printf_unfiltered ("%-*s", addr_width,
-			 local_hex_string_custom ((unsigned long) so->lmend,
-						  addr_fmt));
+			     so->textsection != NULL 
+			       ? local_hex_string_custom (
+			           (unsigned long) so->textsection->endaddr,
+	                           addr_fmt)
+			       : "");
 	  printf_unfiltered ("%-12s", so->symbols_loaded ? "Yes" : "No");
 	  printf_unfiltered ("%s\n", so->so_name);
 	}
@@ -640,10 +614,7 @@ info_sharedlibrary_command (char *ignore, int from_tty)
 
    Provides a hook for other gdb routines to discover whether or
    not a particular address is within the mapped address space of
-   a shared library.  Any address between the base mapping address
-   and the first address beyond the end of the last mapping, is
-   considered to be within the shared library address space, for
-   our purposes.
+   a shared library.
 
    For example, this routine is called at one point to disable
    breakpoints which are in shared libraries that are not currently
@@ -657,9 +628,14 @@ solib_address (CORE_ADDR address)
 
   for (so = so_list_head; so; so = so->next)
     {
-      if (TARGET_SO_LM_ADDR (so) <= address && address < so->lmend)
+      struct section_table *p;
+
+      for (p = so->sections; p < so->sections_end; p++)
+	{
+	  if (p->addr <= address && address < p->endaddr)
 	    return (so->so_name);
 	}
+    }
 
   return (0);
 }

gdb/solist.h

@@ -54,7 +54,6 @@ struct so_list
        are initialized when we actually add it to our symbol tables.  */
 
     bfd *abfd;
-    CORE_ADDR lmend;		/* upper addr bound of mapped object */
     char symbols_loaded;	/* flag: symbols read in yet? */
     char from_tty;		/* flag: print msgs? */
     struct objfile *objfile;	/* objfile for loaded lib */
@@ -65,12 +64,30 @@ struct so_list
 
 struct target_so_ops
   {
-    CORE_ADDR (*lm_addr) (struct so_list *so);
+    /* Adjust the section binding addresses by the base address at
+       which the object was actually mapped.  */
+    void (*relocate_section_addresses) (struct so_list *so,
+                                        struct section_table *);
+
+    /* Free the the link map info and any other private data
+       structures associated with a so_list entry.  */
     void (*free_so) (struct so_list *so);
+
+    /* Reset or free private data structures not associated with
+       so_list entries.  */
     void (*clear_solib) (void);
+
+    /* Target dependent code to run after child process fork.  */
     void (*solib_create_inferior_hook) (void);
+
+    /* Do additional symbol handling, lookup, etc. after symbols
+       for a shared object have been loaded.  */
     void (*special_symbol_handling) (void);
+
+    /* Construct a list of the currently loaded shared objects.  */
     struct so_list *(*current_sos) (void);
+
+    /* Find, open, and read the symbols for the main executable.  */
     int (*open_symbol_file_object) (void *from_ttyp);
   };
 
@@ -79,7 +96,8 @@ void free_so (struct so_list *so);
 /* FIXME: gdbarch needs to control this variable */
 extern struct target_so_ops *current_target_so_ops;
 
-#define TARGET_SO_LM_ADDR (current_target_so_ops->lm_addr)
+#define TARGET_SO_RELOCATE_SECTION_ADDRESSES \
+  (current_target_so_ops->relocate_section_addresses)
 #define TARGET_SO_FREE_SO (current_target_so_ops->free_so)
 #define TARGET_SO_CLEAR_SOLIB (current_target_so_ops->clear_solib)
 #define TARGET_SO_SOLIB_CREATE_INFERIOR_HOOK \