[PATCH 0/1] Fix 'rw_pieced_value' for values casted to different type.

[Stephan Rohr <stephan.rohr@intel.com>]

From: "Rohr, Stephan" <stephan.rohr@intel.com>

This patch provides a fix for the issue when a user wants to print a pieced
value, as described by 'DW_OP_piece' or 'DW_OP_bit_piece', casted to a
different type, e.g. 'print (<type> []) <variable>).

If a lazy value is fetched, GDB allocates space based on the enclosing type's
length and typically reads the 'full' object.  This is not implemented for 
pieced values and causes an internal error if 'type' and 'enclosing_type' of
a value are not identical, which is the case if the user explicitly casts the
variable.

However, GDB can read the value based on its type.  Thus, it should be
sufficient to check if the type's length (potentially shifted by
'embedded_offset') does not exceed the enclosing type's length which was
used for memory allocation.

Test-cases are added to 'gdb/testsuite/gdb.dwarf2/shortpiece.exp'.

The testsuite was run for the following targets:
* unix/-64
* native-gdbserver
* native-extended-gdbserver
* unix/-m32

Rohr, Stephan (1):
  gdb/dwarf2: Fix 'rw_pieced_value' for values casted to different type.

 gdb/dwarf2/expr.c                       |  6 ++----
 gdb/testsuite/gdb.dwarf2/shortpiece.exp | 12 ++++++++++++
 2 files changed, 14 insertions(+), 4 deletions(-)

-- 
2.25.1