gdb unique-ptr (gdb) start (gdb) pt *foo # foo is a std::unique_ptr<> object -> segv The problem, I think, is in value_x_unop: if (noside == EVAL_AVOID_SIDE_EFFECTS) { struct type *return_type; return_type = TYPE_TARGET_TYPE (check_typedef (value_type (argvec[0]))); => return value_zero (return_type, VALUE_LVAL (arg1)); } if (TYPE_CODE (value_type (argvec[0])) == TYPE_CODE_XMETHOD) { /* Static xmethods are not supported yet. */ gdb_assert (static_memfuncp == 0); return call_xmethod (argvec[0], 1, argvec + 1); } else return call_function_by_hand (argvec[0], nargs, argvec + 1); (top-gdb) p argvec[0]->type->main_type->code $6 = TYPE_CODE_XMETHOD xmethods don't have TYPE_TARGET_TYPE, it's NULL. The user would want the result of the ptype command to be the type of the result of the xmethod, not the type of the xmethod. Check for xmethods before EVAL_AVOID_SIDE_EFFECTS? OTOH, the xmethod may well have side effects. Propagate EVAL_AVOID_SIDE_EFFECTS into the xmethod?
Could we extend the xmethod API to add a method XMethodWorker.return_type() and use the returned gdb.Type object to evaluate TYPE_TARGET_TYPE of an xmethod value?
A return_type method sounds good to me.
The master branch has been updated by Doug Evans <devans@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2ce1cdbf84ce883b992bc8ffec3d29b4da229b72 commit 2ce1cdbf84ce883b992bc8ffec3d29b4da229b72 Author: Doug Evans <dje@google.com> Date: Wed Apr 29 13:24:21 2015 -0700 PR python/18285 gdb/ChangeLog: PR python/18285 * NEWS: Document new gdb.XMethodWorker.get_result_type method. * eval.c (evaluate_subexp_standard) <OP_FUNCALL>: Handle EVAL_AVOID_SIDE_EFFECTS for xmethods. * extension-priv.h (struct extension_language_ops) <get_xmethod_result_type>: New member. * extension.c (get_xmethod_result_type): New function. * extension.h (get_xmethod_result_type): Declare. * python/py-xmethods.c (get_result_type_method_name): New static global. (py_get_result_type_method_name): Ditto. (gdbpy_get_xmethod_result_type): New function. (gdbpy_initialize_xmethods): Initialize py_get_result_type_method_name. * python/python-internal.h (gdbpy_get_xmethod_result_type): Declare. * python/python.c (python_extension_ops): Add gdbpy_get_xmethod_result_type. * python/lib/gdb/xmethod.py (XMethodWorker): Add get_result_type. * valarith.c (value_x_binop): Handle EVAL_AVOID_SIDE_EFFECTS for xmethods. (value_x_unop): Ditto. * value.c (result_type_of_xmethod): New function. * value.h (result_type_of_xmethod): Declare. gdb/testsuite/ChangeLog: * gdb.python/py-xmethods.exp: Add ptype tests. * gdb.python/py-xmethods.py (E_method_char_worker): Add get_result_type method. gdb/doc/ChangeLog: * python.texi (Xmethod API) <gdb.XMethodWorker.get_result_type>: Document. (Writing an Xmethod): Add get_result_type to example.
The gdb-7.9-branch branch has been updated by Doug Evans <devans@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6b2a76d583a91ae9dad0653c60c91b72f07ff941 commit 6b2a76d583a91ae9dad0653c60c91b72f07ff941 Author: Doug Evans <dje@google.com> Date: Tue May 12 09:18:06 2015 -0700 PR python/18285 gdb/ChangeLog: PR python/18285 * NEWS: Document new gdb.XMethodWorker.get_result_type method. * eval.c (evaluate_subexp_standard) <OP_FUNCALL>: Handle EVAL_AVOID_SIDE_EFFECTS for xmethods. * extension-priv.h (struct extension_language_ops) <get_xmethod_result_type>: New member. * extension.c (get_xmethod_result_type): New function. * extension.h (get_xmethod_result_type): Declare. * python/py-xmethods.c (get_result_type_method_name): New static global. (py_get_result_type_method_name): Ditto. (gdbpy_get_xmethod_result_type): New function. (gdbpy_initialize_xmethods): Initialize py_get_result_type_method_name. * python/python-internal.h (gdbpy_get_xmethod_result_type): Declare. * python/python.c (python_extension_ops): Add gdbpy_get_xmethod_result_type. * python/lib/gdb/xmethod.py (XMethodWorker): Add get_result_type. * valarith.c (value_x_binop): Handle EVAL_AVOID_SIDE_EFFECTS for xmethods. (value_x_unop): Ditto. * value.c (result_type_of_xmethod): New function. * value.h (result_type_of_xmethod): Declare. gdb/testsuite/ChangeLog: * gdb.python/py-xmethods.exp: Add ptype tests. * gdb.python/py-xmethods.py (E_method_char_worker): Add get_result_type method. gdb/doc/ChangeLog: * python.texi (Xmethod API) <gdb.XMethodWorker.get_result_type>: Document. (Writing an Xmethod): Add get_result_type to example.
patch committed.