Changes by Peter.Schauer to fix gdb/13521 -- gdb step command fails to step

from a function in one dynamically linked library into a function in another
dynamically linked library.

1 files changed, 95 insertions, 7 deletions

diff --git a/gdb/solib.c b/gdb/solib.c
index b8fffd7..b09b140 100644
--- a/gdb/solib.c
+++ b/gdb/solib.c
@@ -1,5 +1,5 @@
 /* Handle SunOS and SVR4 shared libraries for GDB, the GNU Debugger.
-   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996
+   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998
    Free Software Foundation, Inc.
    
 This file is part of GDB.
@@ -70,6 +70,7 @@ static char *solib_break_names[] = {
   "r_debug_state",
   "_r_debug_state",
   "_dl_debug_state",
+  "rtld_db_dlactivity",
   NULL
 };
 #endif
@@ -148,12 +149,20 @@ static struct so_list *so_list_head;	/* List of known shared objects */
 static CORE_ADDR debug_base;		/* Base of dynamic linker structures */
 static CORE_ADDR breakpoint_addr;	/* Address where end bkpt is set */
 
+static int solib_cleanup_queued = 0;    /* make_run_cleanup called */
+
 extern int
 fdmatch PARAMS ((int, int));		/* In libiberty */
 
 /* Local function prototypes */
 
 static void
+do_clear_solib PARAMS ((PTR));
+
+static int
+match_main PARAMS ((char *));
+
+static void
 special_symbol_handling PARAMS ((struct so_list *));
 
 static void
@@ -936,6 +945,13 @@ find_solib (so_list_ptr)
       else
 	{
 	  so_list_head = new;
+
+	  if (! solib_cleanup_queued)
+	    {
+	      make_run_cleanup (do_clear_solib);
+	      solib_cleanup_queued = 1;
+	    }
+	  
 	}      
       so_list_next = new;
       read_memory ((CORE_ADDR) lm, (char *) &(new -> lm),
@@ -970,12 +986,34 @@ symbol_add_stub (arg)
      char *arg;
 {
   register struct so_list *so = (struct so_list *) arg;	/* catch_errs bogon */
+  CORE_ADDR text_addr = 0;
+
+  if (so -> textsection)
+    text_addr = so -> textsection -> addr;
+  else
+    {
+      asection *lowest_sect;
+
+      /* If we didn't find a mapped non zero sized .text section, set up
+	 text_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)
+	text_addr = bfd_section_vma (so -> abfd, lowest_sect)
+		    + (CORE_ADDR) LM_ADDR (so);
+    }
   
+  ALL_OBJFILES (so -> objfile)
+    {
+      if (strcmp (so -> objfile -> name, so -> so_name) == 0)
+	return 1;
+    }
   so -> objfile =
     symbol_file_add (so -> so_name, so -> from_tty,
-		     (so->textsection == NULL
-		      ? 0
-		      : (unsigned int) so -> textsection -> addr),
+		     text_addr,
 		     0, 0, 0);
   return (1);
 }
@@ -1262,6 +1300,34 @@ clear_solib()
   debug_base = 0;
 }
 
+static void
+do_clear_solib (dummy)
+     PTR dummy;
+{
+  solib_cleanup_queued = 0;
+  clear_solib ();
+}
+
+#ifdef SVR4_SHARED_LIBS
+
+/* Return 1 if PC lies in the dynamic symbol resolution code of the
+   SVR4 run time loader.  */
+
+static CORE_ADDR interp_text_sect_low;
+static CORE_ADDR interp_text_sect_high;
+static CORE_ADDR interp_plt_sect_low;
+static CORE_ADDR interp_plt_sect_high;
+
+int
+in_svr4_dynsym_resolve_code (pc)
+     CORE_ADDR pc;
+{
+  return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
+	  || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
+	  || in_plt_section (pc, NULL));
+}
+#endif
+
 /*
 
 LOCAL FUNCTION
@@ -1422,6 +1488,9 @@ enable_break ()
   remove_solib_event_breakpoints ();
 
 #ifdef SVR4_SHARED_LIBS
+  interp_text_sect_low = interp_text_sect_high = 0;
+  interp_plt_sect_low = interp_plt_sect_high = 0;
+
   /* Find the .interp section; if not found, warn the user and drop
      into the old breakpoint at symbol code.  */
   interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
@@ -1465,6 +1534,25 @@ enable_break ()
 	 linker) and subtracting the offset of the entry point.  */
       load_addr = read_pc () - tmp_bfd->start_address;
 
+      /* Record the relocated start and end address of the dynamic linker
+	 text and plt section for in_svr4_dynsym_resolve_code.  */
+      interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
+      if (interp_sect)
+	{
+	  interp_text_sect_low =
+	    bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
+	  interp_text_sect_high =
+	    interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect);
+	}
+      interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
+      if (interp_sect)
+	{
+	  interp_plt_sect_low =
+	    bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
+	  interp_plt_sect_high =
+	    interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect);
+	}
+
       /* Now try to set a breakpoint in the dynamic linker.  */
       for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
 	{
@@ -1506,7 +1594,7 @@ bkpt_at_symbol:
     }
 
   /* Nothing good happened.  */
-  return 0;
+  success = 0;
 
 #endif	/* BKPT_AT_SYMBOL */
 
@@ -1747,14 +1835,14 @@ must be loaded manually, using `sharedlibrary'.",
   add_show_from_set
     (add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
 		  (char *) &solib_absolute_prefix,
-		  "Set prefix for loading absolute shared library symbol files.\n
+		  "Set prefix for loading absolute shared library symbol files.\n\
 For other (relative) files, you can add values using `set solib-search-path'.",
 		  &setlist),
      &showlist);
   add_show_from_set
     (add_set_cmd ("solib-search-path", class_support, var_string,
 		  (char *) &solib_search_path,
-		  "Set the search path for loading non-absolute shared library symbol files.\n
+		  "Set the search path for loading non-absolute shared library symbol files.\n\
 This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
 		  &setlist),
      &showlist);