Check for NULL selected_frame in various places.

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index e5d3c69c8d6a615441ea76d9b18326b5a3a2ee09..e3f515221c63ac6db8047dca43cc91696676b2ba 100644 (file)
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1537,14 +1537,22 @@ get_catch_sals (this_level_only)
 {
   extern struct blockvector *blockvector_for_pc ();
   register struct blockvector *bl;
-  register struct block *block = get_frame_block (selected_frame);
+  register struct block *block;
   int index, have_default = 0;
-  struct frame_info *fi = get_frame_info (selected_frame);
-  CORE_ADDR pc = fi->pc;
+  struct frame_info *fi;
+  CORE_ADDR pc;
   struct symtabs_and_lines sals;
   struct sal_chain *sal_chain = 0;
   char *blocks_searched;
 
+  /* Not sure whether an error message is always the correct response,
+     but it's better than a core dump.  */
+  if (selected_frame == NULL)
+    error ("No selected frame.");
+  block = get_frame_block (selected_frame);
+  fi = get_frame_info (selected_frame);
+  pc = fi->pc;
+
   sals.nelts = 0;
   sals.sals = NULL;
 

diff --git a/gdb/exec.c b/gdb/exec.c
index 730692ae9273b96f998d6026aefa661d2e3845e0..32795c640fb5ec5e1c89a59af4953e1f1e8e8e99 100644 (file)
--- a/gdb/exec.c
+++ b/gdb/exec.c
@@ -193,6 +193,8 @@ build_section_table (some_bfd, start, end)
   count = bfd_count_sections (some_bfd);
   if (count == 0)
     abort();   /* return 1? */
+  if (*start)
+    free (*start);
   *start = (struct section_table *) xmalloc (count * sizeof (**start));
   *end = *start;
   bfd_map_over_sections (some_bfd, add_to_section_table, end);

diff --git a/gdb/findvar.c b/gdb/findvar.c
index 25ff0baf6d03b0a92a72af95ca1f9846a64ab6e5..5ac03bc448602c91c06d76445f8547379617eb10 100644 (file)
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -354,7 +354,8 @@ supply_register (regno, val)
 /* Given a struct symbol for a variable,
    and a stack frame id, read the value of the variable
    and return a (pointer to a) struct value containing the value. 
-   If the variable cannot be found, return a zero pointer.  */
+   If the variable cannot be found, return a zero pointer.
+   If FRAME is NULL, use the selected_frame.  */
 
 value
 read_var_value (var, frame)
@@ -411,6 +412,8 @@ read_var_value (var, frame)
 
     case LOC_ARG:
       fi = get_frame_info (frame);
+      if (fi == NULL)
+       return 0;
       addr = FRAME_ARGS_ADDRESS (fi);
       if (!addr) {
        return 0;
@@ -420,6 +423,8 @@ read_var_value (var, frame)
       
     case LOC_REF_ARG:
       fi = get_frame_info (frame);
+      if (fi == NULL)
+       return 0;
       addr = FRAME_ARGS_ADDRESS (fi);
       if (!addr) {
        return 0;
@@ -431,6 +436,8 @@ read_var_value (var, frame)
     case LOC_LOCAL:
     case LOC_LOCAL_ARG:
       fi = get_frame_info (frame);
+      if (fi == NULL)
+       return 0;
       addr = SYMBOL_VALUE (var) + FRAME_LOCALS_ADDRESS (fi);
       break;
 
@@ -445,8 +452,12 @@ read_var_value (var, frame)
     case LOC_REGISTER:
     case LOC_REGPARM:
       {
-       struct block *b = get_frame_block (frame);
+       struct block *b;
 
+       if (frame == NULL)
+         return 0;
+       b = get_frame_block (frame);
+       
        v = value_from_register (type, SYMBOL_VALUE (var), frame);
 
        if (REG_STRUCT_HAS_ADDR(b->gcc_compile_flag)

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 25883a0a93ccea57f022729aebfed208679ba61e..2ebfb0b1c3c6f12b98fe45cd9465b981944c539c 100644 (file)
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -529,6 +529,8 @@ finish_command (arg, from_tty)
     error ("The \"finish\" command does not take any arguments.");
   if (!target_has_execution)
     error ("The program is not running.");
+  if (selected_frame == NULL)
+    error ("No selected frame.");
 
   frame = get_prev_frame (selected_frame);
   if (frame == 0)

diff --git a/gdb/inflow.c b/gdb/inflow.c
index 6e6905fd50897e9fb7253bccaaa7e1d47dab8ce9..3d0c68aea59a365592e602e5a43f61bbea4c5858 100644 (file)
--- a/gdb/inflow.c
+++ b/gdb/inflow.c
@@ -364,6 +364,16 @@ kill_command (arg, from_tty)
   if (!query ("Kill the inferior process? "))
     error ("Not confirmed.");
   target_kill (arg, from_tty);
+
+  /* Killing off the inferior can leave us with a core file.  If so,
+     print the state we are left in.  */
+  if (target_has_stack) {
+    printf_filtered ("In %s,\n", current_target->to_longname);
+    if (selected_frame == NULL)
+      fputs_filtered ("No selected stack frame.\n", stdout);
+    else
+      print_sel_frame (0);
+  }
 }
 
 /* The inferior process has died.  Long live the inferior!  */
@@ -381,13 +391,15 @@ generic_mourn_inferior ()
   CLEAR_DEFERRED_STORES;
 #endif
 
-  select_frame ((FRAME) 0, -1);
   reopen_exec_file ();
-  if (target_has_stack)
+  if (target_has_stack) {
     set_current_frame ( create_new_frame (read_register (FP_REGNUM),
                                          read_pc ()));
-  else
+    select_frame (get_current_frame (), 0);
+  } else {
     set_current_frame (0);
+    select_frame ((FRAME) 0, -1);
+  }
   /* It is confusing to the user for ignore counts to stick around
      from previous runs of the inferior.  So clear them.  */
   breakpoint_clear_ignore_counts ();

diff --git a/gdb/infrun.c b/gdb/infrun.c
index ac15f37d10938ea988a5a598e5a755fbfd66ad42..0c3a3e80e99e4d548bc21d0dc2665e573ed42eb6 100644 (file)
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -1605,6 +1605,8 @@ restore_inferior_status (inf_status)
       fid = find_relative_frame (get_current_frame (),
                                 &level);
 
+      /* If inf_status->selected_frame_address is NULL, there was no
+        previously selected frame.  */
       if (fid == 0 ||
          FRAME_FP (fid) != inf_status->selected_frame_address ||
          level != 0)

diff --git a/gdb/stack.c b/gdb/stack.c
index 09920130b78ec8fe64f0cdd7a2f36ba1d22266f3..e8041fb8422aa0e2e3d26bda2c72d87fbac9068a 100644 (file)
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -221,6 +221,8 @@ extern FRAME setup_arbitrary_frame ();
 
 /*
  * Read a frame specification in whatever the appropriate format is.
+ * Call error() if the specification is in any way invalid (i.e.
+ * this function never returns NULL).
  */
 static FRAME
 parse_frame_specification (frame_exp)
@@ -262,6 +264,8 @@ parse_frame_specification (frame_exp)
   switch (numargs)
     {
     case 0:
+      if (selected_frame == NULL)
+       error ("No selected frame.");
       return selected_frame;
       /* NOTREACHED */
     case 1:
@@ -477,6 +481,9 @@ backtrace_command (count_exp, from_tty)
   register FRAME trailing;
   register int trailing_level;
 
+  if (!target_has_stack)
+    error ("No stack.");
+
   /* The following code must do two things.  First, it must
      set the variable TRAILING to the frame from which we should start
      printing.  Second, it must set the variable count to the number
@@ -846,14 +853,15 @@ select_frame (frame, level)
     find_pc_symtab (get_frame_info (frame)->pc);
 }
 
-/* Store the selected frame and its level into *FRAMEP and *LEVELP.  */
+/* Store the selected frame and its level into *FRAMEP and *LEVELP.
+   If there is no selected frame, *FRAMEP is set to NULL.  */
 
 void
 record_selected_frame (frameaddrp, levelp)
      FRAME_ADDR *frameaddrp;
      int *levelp;
 {
-  *frameaddrp = FRAME_FP (selected_frame);
+  *frameaddrp = selected_frame ? FRAME_FP (selected_frame) : NULL;
   *levelp = selected_frame_level;
 }
 
@@ -1028,11 +1036,17 @@ return_command (retval_exp, from_tty)
      char *retval_exp;
      int from_tty;
 {
-  struct symbol *thisfun = get_frame_function (selected_frame);
-  FRAME_ADDR selected_frame_addr = FRAME_FP (selected_frame);
-  CORE_ADDR selected_frame_pc = (get_frame_info (selected_frame))->pc;
+  struct symbol *thisfun;
+  FRAME_ADDR selected_frame_addr;
+  CORE_ADDR selected_frame_pc;
   FRAME frame;
 
+  if (selected_frame == NULL)
+    error ("No selected frame.");
+  thisfun = get_frame_function (selected_frame);
+  selected_frame_addr = FRAME_FP (selected_frame);
+  selected_frame_pc = (get_frame_info (selected_frame))->pc;
+
   /* If interactive, require confirmation.  */
 
   if (from_tty)