gas/

[deliverable/binutils-gdb.git] / gdb / dwarf2loc.c

diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index ab4ecee8244edbb9e0b48bd625d612d9e2cf75d1..02afcdf339bf6e07b6a9df8ed3a119fd499b712e 100644 (file)
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -42,8 +42,6 @@
 #include "gdb_string.h"
 #include "gdb_assert.h"
 
-DEF_VEC_I(int);
-
 extern int dwarf2_always_disassemble;
 
 static void dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
@@ -90,6 +88,16 @@ enum debug_loc_kind
   DEBUG_LOC_INVALID_ENTRY = -2
 };
 
+/* Helper function which throws an error if a synthetic pointer is
+   invalid.  */
+
+static void
+invalid_synthetic_pointer (void)
+{
+  error (_("access outside bounds of object "
+          "referenced via synthetic pointer"));
+}
+
 /* Decode the addresses in a non-dwo .debug_loc entry.
    A pointer to the next byte to examine is returned in *NEW_PTR.
    The encoded low,high addresses are return in *LOW,*HIGH.
@@ -1631,8 +1639,6 @@ read_pieced_value (struct value *v)
          bits_to_skip -= this_size_bits;
          continue;
        }
-      if (this_size_bits > type_len - offset)
-       this_size_bits = type_len - offset;
       if (bits_to_skip > 0)
        {
          dest_offset_bits = 0;
@@ -1645,6 +1651,8 @@ read_pieced_value (struct value *v)
          dest_offset_bits = offset;
          source_offset_bits = 0;
        }
+      if (this_size_bits > type_len - offset)
+       this_size_bits = type_len - offset;
 
       this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
       source_offset = source_offset_bits / 8;
@@ -2077,8 +2085,15 @@ indirect_pieced_value (struct value *value)
 
   frame = get_selected_frame (_("No frame selected."));
 
-  /* This is an offset requested by GDB, such as value subcripts.  */
+  /* This is an offset requested by GDB, such as value subscripts.
+     However, due to how synthetic pointers are implemented, this is
+     always presented to us as a pointer type.  This means we have to
+     sign-extend it manually as appropriate.  */
   byte_offset = value_as_address (value);
+  if (TYPE_LENGTH (value_type (value)) < sizeof (LONGEST))
+    byte_offset = gdb_sign_extend (byte_offset,
+                                  8 * TYPE_LENGTH (value_type (value)));
+  byte_offset += piece->v.ptr.offset;
 
   gdb_assert (piece);
   baton
@@ -2086,9 +2101,37 @@ indirect_pieced_value (struct value *value)
                                     get_frame_address_in_block_wrapper,
                                     frame);
 
-  return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
-                                       baton.data, baton.size, baton.per_cu,
-                                       piece->v.ptr.offset + byte_offset);
+  if (baton.data != NULL)
+    return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
+                                         baton.data, baton.size, baton.per_cu,
+                                         byte_offset);
+
+  {
+    struct obstack temp_obstack;
+    struct cleanup *cleanup;
+    const gdb_byte *bytes;
+    LONGEST len;
+    struct value *result;
+
+    obstack_init (&temp_obstack);
+    cleanup = make_cleanup_obstack_free (&temp_obstack);
+
+    bytes = dwarf2_fetch_constant_bytes (piece->v.ptr.die, c->per_cu,
+                                        &temp_obstack, &len);
+    if (bytes == NULL)
+      result = allocate_optimized_out_value (TYPE_TARGET_TYPE (type));
+    else
+      {
+       if (byte_offset < 0
+           || byte_offset + TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > len)
+         invalid_synthetic_pointer ();
+       bytes += byte_offset;
+       result = value_from_contents (TYPE_TARGET_TYPE (type), bytes);
+      }
+
+    do_cleanups (cleanup);
+    return result;
+  }
 }
 
 static void *
@@ -2134,16 +2177,6 @@ static const struct lval_funcs pieced_value_funcs = {
   free_pieced_value_closure
 };
 
-/* Helper function which throws an error if a synthetic pointer is
-   invalid.  */
-
-static void
-invalid_synthetic_pointer (void)
-{
-  error (_("access outside bounds of object "
-          "referenced via synthetic pointer"));
-}
-
 /* Virtual method table for dwarf2_evaluate_loc_desc_full below.  */
 
 static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs =