Avoid NULL dereference.

[deliverable/binutils-gdb.git] / gdb / findvar.c

diff --git a/gdb/findvar.c b/gdb/findvar.c
index a56650df4fd88a96bdc433705c4e0e6a3454e104..1048887fdc061cba49de10437d100665ded55df7 100644 (file)
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -382,8 +382,7 @@ symbol_read_needs_frame (struct symbol *sym)
 /* 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 FRAME is NULL, use the selected frame.  */
+   If the variable cannot be found, return a zero pointer.  */
 
 struct value *
 read_var_value (struct symbol *var, struct frame_info *frame)
@@ -405,10 +404,8 @@ read_var_value (struct symbol *var, struct frame_info *frame)
 
   len = TYPE_LENGTH (type);
 
-  /* FIXME drow/2003-09-06: this call to the selected frame should be
-     pushed upwards to the callers.  */
-  if (frame == NULL)
-    frame = deprecated_safe_get_selected_frame ();
+  if (symbol_read_needs_frame (var))
+    gdb_assert (frame);
 
   switch (SYMBOL_CLASS (var))
     {
@@ -450,8 +447,6 @@ read_var_value (struct symbol *var, struct frame_info *frame)
       break;
 
     case LOC_ARG:
-      if (frame == NULL)
-       return 0;
       addr = get_frame_args_address (frame);
       if (!addr)
        return 0;
@@ -462,8 +457,6 @@ read_var_value (struct symbol *var, struct frame_info *frame)
       {
        struct value *ref;
        CORE_ADDR argref;
-       if (frame == NULL)
-         return 0;
        argref = get_frame_args_address (frame);
        if (!argref)
          return 0;
@@ -474,8 +467,6 @@ read_var_value (struct symbol *var, struct frame_info *frame)
       }
 
     case LOC_LOCAL:
-      if (frame == NULL)
-       return 0;
       addr = get_frame_locals_address (frame);
       addr += SYMBOL_VALUE (var);
       break;
@@ -498,9 +489,6 @@ read_var_value (struct symbol *var, struct frame_info *frame)
        int regno = SYMBOL_VALUE (var);
        struct value *regval;
 
-       if (frame == NULL)
-         return 0;
-
        if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR)
          {
            regval = value_from_register (lookup_pointer_type (type),
@@ -530,8 +518,6 @@ read_var_value (struct symbol *var, struct frame_info *frame)
         Unfortunately DWARF 2 stores the frame-base (instead of the
         function) location in a function's symbol.  Oops!  For the
         moment enable this when/where applicable.  */
-      if (frame == 0 && SYMBOL_OPS (var)->read_needs_frame (var))
-       return 0;
       return SYMBOL_OPS (var)->read_variable (var, frame);
 
     case LOC_UNRESOLVED:
@@ -657,58 +643,3 @@ address_from_register (struct type *type, int regnum, struct frame_info *frame)
 
   return result;
 }
-
-\f
-/* Given a struct symbol for a variable or function,
-   and a stack frame id, 
-   return a (pointer to a) struct value containing the properly typed
-   address.  */
-
-struct value *
-locate_var_value (struct symbol *var, struct frame_info *frame)
-{
-  struct gdbarch *gdbarch;
-  CORE_ADDR addr = 0;
-  struct type *type = SYMBOL_TYPE (var);
-  struct value *lazy_value;
-
-  /* Evaluate it first; if the result is a memory address, we're fine.
-     Lazy evaluation pays off here. */
-
-  lazy_value = read_var_value (var, frame);
-  if (lazy_value == 0)
-    error (_("Address of \"%s\" is unknown."), SYMBOL_PRINT_NAME (var));
-
-  if ((VALUE_LVAL (lazy_value) == lval_memory && value_lazy (lazy_value))
-      || TYPE_CODE (type) == TYPE_CODE_FUNC)
-    {
-      struct value *val;
-
-      addr = VALUE_ADDRESS (lazy_value);
-      val = value_from_pointer (lookup_pointer_type (type), addr);
-      return val;
-    }
-
-  /* Not a memory address; check what the problem was.  */
-  switch (VALUE_LVAL (lazy_value))
-    {
-    case lval_register:
-      gdb_assert (frame);
-      gdbarch = get_frame_arch (frame);
-      gdb_assert (gdbarch_register_name
-                  (gdbarch, VALUE_REGNUM (lazy_value)) != NULL
-                 && *gdbarch_register_name
-                   (gdbarch, VALUE_REGNUM (lazy_value)) != '\0');
-      error (_("Address requested for identifier "
-              "\"%s\" which is in register $%s"),
-            SYMBOL_PRINT_NAME (var), 
-           gdbarch_register_name (gdbarch, VALUE_REGNUM (lazy_value)));
-      break;
-
-    default:
-      error (_("Can't take address of \"%s\" which isn't an lvalue."),
-            SYMBOL_PRINT_NAME (var));
-      break;
-    }
-  return 0;                    /* For lint -- never reached */
-}