Add a TRY_CATCH to get_prev_frame_always to better manage errors during unwind.

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

diff --git a/gdb/findvar.c b/gdb/findvar.c
index 998a799e3bed6147ee61611a76735bfd22687dc7..9390c8a7b88d15952db73948c6724dbfeb6413cb 100644 (file)
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -625,15 +625,14 @@ read_var_value (struct symbol *var, struct frame_info *frame)
 /* Install default attributes for register values.  */
 
 struct value *
-default_value_from_register (struct type *type, int regnum,
-                            struct frame_info *frame)
+default_value_from_register (struct gdbarch *gdbarch, struct type *type,
+                             int regnum, struct frame_id frame_id)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
   int len = TYPE_LENGTH (type);
   struct value *value = allocate_value (type);
 
   VALUE_LVAL (value) = lval_register;
-  VALUE_FRAME_ID (value) = get_frame_id (frame);
+  VALUE_FRAME_ID (value) = frame_id;
   VALUE_REGNUM (value) = regnum;
 
   /* Any structure stored in more than one register will always be
@@ -741,7 +740,8 @@ value_from_register (struct type *type, int regnum, struct frame_info *frame)
   else
     {
       /* Construct the value.  */
-      v = gdbarch_value_from_register (gdbarch, type, regnum, frame);
+      v = gdbarch_value_from_register (gdbarch, type,
+                                      regnum, get_frame_id (frame));
 
       /* Get the data.  */
       read_frame_register_value (v, frame);
@@ -750,18 +750,30 @@ value_from_register (struct type *type, int regnum, struct frame_info *frame)
   return v;
 }
 
-/* Return contents of register REGNUM in frame FRAME as address,
-   interpreted as value of type TYPE.   Will abort if register
-   value is not available.  */
+/* Return contents of register REGNUM in frame FRAME as address.
+   Will abort if register value is not available.  */
 
 CORE_ADDR
-address_from_register (struct type *type, int regnum, struct frame_info *frame)
+address_from_register (int regnum, struct frame_info *frame)
 {
+  struct gdbarch *gdbarch = get_frame_arch (frame);
+  struct type *type = builtin_type (gdbarch)->builtin_data_ptr;
   struct value *value;
   CORE_ADDR result;
 
-  value = value_from_register (type, regnum, frame);
-  gdb_assert (value);
+  /* This routine may be called during early unwinding, at a time
+     where the ID of FRAME is not yet known.  Calling value_from_register
+     would therefore abort in get_frame_id.  However, since we only need
+     a temporary value that is never used as lvalue, we actually do not
+     really need to set its VALUE_FRAME_ID.  Therefore, we re-implement
+     the core of value_from_register, but use the null_frame_id.
+
+     This works only if we do not require a special conversion routine,
+     which is true for plain pointer types for all current targets.  */
+  gdb_assert (!gdbarch_convert_register_p (gdbarch, regnum, type));
+
+  value = gdbarch_value_from_register (gdbarch, type, regnum, null_frame_id);
+  read_frame_register_value (value, frame);
 
   if (value_optimized_out (value))
     {