diff options
| -rw-r--r-- | gdb/ChangeLog | 7 | ||||
| -rw-r--r-- | gdb/value.c | 303 |
2 files changed, 169 insertions, 141 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f1eed4e..9895d2f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2018-06-02 Simon Marchi <simon.marchi@ericsson.com> + + * value.c (value_fetch_lazy_bitfield): New. + (value_fetch_lazy_memory): New. + (value_fetch_lazy_register): New. + (value_fetch_lazy): Factor out to smaller functions. + 2018-06-01 Tom Tromey <tom@tromey.com> * cp-name-parser.y (backslashable, represented): Now const. diff --git a/gdb/value.c b/gdb/value.c index 6bb6b8e..146ce8e 100644 --- a/gdb/value.c +++ b/gdb/value.c @@ -3714,6 +3714,165 @@ value_initialized (const struct value *val) return val->initialized; } +/* Helper for value_fetch_lazy when the value is a bitfield. */ + +static void +value_fetch_lazy_bitfield (struct value *val) +{ + gdb_assert (value_bitsize (val) != 0); + + /* To read a lazy bitfield, read the entire enclosing value. This + prevents reading the same block of (possibly volatile) memory once + per bitfield. It would be even better to read only the containing + word, but we have no way to record that just specific bits of a + value have been fetched. */ + struct type *type = check_typedef (value_type (val)); + struct value *parent = value_parent (val); + + if (value_lazy (parent)) + value_fetch_lazy (parent); + + unpack_value_bitfield (val, value_bitpos (val), value_bitsize (val), + value_contents_for_printing (parent), + value_offset (val), parent); +} + +/* Helper for value_fetch_lazy when the value is in memory. */ + +static void +value_fetch_lazy_memory (struct value *val) +{ + gdb_assert (VALUE_LVAL (val) == lval_memory); + + CORE_ADDR addr = value_address (val); + struct type *type = check_typedef (value_enclosing_type (val)); + + if (TYPE_LENGTH (type)) + read_value_memory (val, 0, value_stack (val), + addr, value_contents_all_raw (val), + type_length_units (type)); +} + +/* Helper for value_fetch_lazy when the value is in a register. */ + +static void +value_fetch_lazy_register (struct value *val) +{ + struct frame_info *next_frame; + int regnum; + struct type *type = check_typedef (value_type (val)); + struct value *new_val = val, *mark = value_mark (); + + /* Offsets are not supported here; lazy register values must + refer to the entire register. */ + gdb_assert (value_offset (val) == 0); + + while (VALUE_LVAL (new_val) == lval_register && value_lazy (new_val)) + { + struct frame_id next_frame_id = VALUE_NEXT_FRAME_ID (new_val); + + next_frame = frame_find_by_id (next_frame_id); + regnum = VALUE_REGNUM (new_val); + + gdb_assert (next_frame != NULL); + + /* Convertible register routines are used for multi-register + values and for interpretation in different types + (e.g. float or int from a double register). Lazy + register values should have the register's natural type, + so they do not apply. */ + gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame), + regnum, type)); + + /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID. + Since a "->next" operation was performed when setting + this field, we do not need to perform a "next" operation + again when unwinding the register. That's why + frame_unwind_register_value() is called here instead of + get_frame_register_value(). */ + new_val = frame_unwind_register_value (next_frame, regnum); + + /* If we get another lazy lval_register value, it means the + register is found by reading it from NEXT_FRAME's next frame. + frame_unwind_register_value should never return a value with + the frame id pointing to NEXT_FRAME. If it does, it means we + either have two consecutive frames with the same frame id + in the frame chain, or some code is trying to unwind + behind get_prev_frame's back (e.g., a frame unwind + sniffer trying to unwind), bypassing its validations. In + any case, it should always be an internal error to end up + in this situation. */ + if (VALUE_LVAL (new_val) == lval_register + && value_lazy (new_val) + && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val), next_frame_id)) + internal_error (__FILE__, __LINE__, + _("infinite loop while fetching a register")); + } + + /* If it's still lazy (for instance, a saved register on the + stack), fetch it. */ + if (value_lazy (new_val)) + value_fetch_lazy (new_val); + + /* Copy the contents and the unavailability/optimized-out + meta-data from NEW_VAL to VAL. */ + set_value_lazy (val, 0); + value_contents_copy (val, value_embedded_offset (val), + new_val, value_embedded_offset (new_val), + type_length_units (type)); + + if (frame_debug) + { + struct gdbarch *gdbarch; + struct frame_info *frame; + /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID, + so that the frame level will be shown correctly. */ + frame = frame_find_by_id (VALUE_FRAME_ID (val)); + regnum = VALUE_REGNUM (val); + gdbarch = get_frame_arch (frame); + + fprintf_unfiltered (gdb_stdlog, + "{ value_fetch_lazy " + "(frame=%d,regnum=%d(%s),...) ", + frame_relative_level (frame), regnum, + user_reg_map_regnum_to_name (gdbarch, regnum)); + + fprintf_unfiltered (gdb_stdlog, "->"); + if (value_optimized_out (new_val)) + { + fprintf_unfiltered (gdb_stdlog, " "); + val_print_optimized_out (new_val, gdb_stdlog); + } + else + { + int i; + const gdb_byte *buf = value_contents (new_val); + + if (VALUE_LVAL (new_val) == lval_register) + fprintf_unfiltered (gdb_stdlog, " register=%d", + VALUE_REGNUM (new_val)); + else if (VALUE_LVAL (new_val) == lval_memory) + fprintf_unfiltered (gdb_stdlog, " address=%s", + paddress (gdbarch, + value_address (new_val))); + else + fprintf_unfiltered (gdb_stdlog, " computed"); + + fprintf_unfiltered (gdb_stdlog, " bytes="); + fprintf_unfiltered (gdb_stdlog, "["); + for (i = 0; i < register_size (gdbarch, regnum); i++) + fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]); + fprintf_unfiltered (gdb_stdlog, "]"); + } + + fprintf_unfiltered (gdb_stdlog, " }\n"); + } + + /* Dispose of the intermediate values. This prevents + watchpoints from trying to watch the saved frame pointer. */ + value_free_to_mark (mark); +} + /* Load the actual content of a lazy value. Fetch the data from the user's process and clear the lazy flag to indicate that the data in the buffer is valid. @@ -3733,149 +3892,11 @@ value_fetch_lazy (struct value *val) gdb_assert (val->optimized_out.empty ()); gdb_assert (val->unavailable.empty ()); if (value_bitsize (val)) - { - /* To read a lazy bitfield, read the entire enclosing value. This - prevents reading the same block of (possibly volatile) memory once - per bitfield. It would be even better to read only the containing - word, but we have no way to record that just specific bits of a - value have been fetched. */ - struct type *type = check_typedef (value_type (val)); - struct value *parent = value_parent (val); - - if (value_lazy (parent)) - value_fetch_lazy (parent); - - unpack_value_bitfield (val, - value_bitpos (val), value_bitsize (val), - value_contents_for_printing (parent), - value_offset (val), parent); - } + value_fetch_lazy_bitfield (val); else if (VALUE_LVAL (val) == lval_memory) - { - CORE_ADDR addr = value_address (val); - struct type *type = check_typedef (value_enclosing_type (val)); - - if (TYPE_LENGTH (type)) - read_value_memory (val, 0, value_stack (val), - addr, value_contents_all_raw (val), - type_length_units (type)); - } + value_fetch_lazy_memory (val); else if (VALUE_LVAL (val) == lval_register) - { - struct frame_info *next_frame; - int regnum; - struct type *type = check_typedef (value_type (val)); - struct value *new_val = val, *mark = value_mark (); - - /* Offsets are not supported here; lazy register values must - refer to the entire register. */ - gdb_assert (value_offset (val) == 0); - - while (VALUE_LVAL (new_val) == lval_register && value_lazy (new_val)) - { - struct frame_id next_frame_id = VALUE_NEXT_FRAME_ID (new_val); - - next_frame = frame_find_by_id (next_frame_id); - regnum = VALUE_REGNUM (new_val); - - gdb_assert (next_frame != NULL); - - /* Convertible register routines are used for multi-register - values and for interpretation in different types - (e.g. float or int from a double register). Lazy - register values should have the register's natural type, - so they do not apply. */ - gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame), - regnum, type)); - - /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID. - Since a "->next" operation was performed when setting - this field, we do not need to perform a "next" operation - again when unwinding the register. That's why - frame_unwind_register_value() is called here instead of - get_frame_register_value(). */ - new_val = frame_unwind_register_value (next_frame, regnum); - - /* If we get another lazy lval_register value, it means the - register is found by reading it from NEXT_FRAME's next frame. - frame_unwind_register_value should never return a value with - the frame id pointing to NEXT_FRAME. If it does, it means we - either have two consecutive frames with the same frame id - in the frame chain, or some code is trying to unwind - behind get_prev_frame's back (e.g., a frame unwind - sniffer trying to unwind), bypassing its validations. In - any case, it should always be an internal error to end up - in this situation. */ - if (VALUE_LVAL (new_val) == lval_register - && value_lazy (new_val) - && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val), next_frame_id)) - internal_error (__FILE__, __LINE__, - _("infinite loop while fetching a register")); - } - - /* If it's still lazy (for instance, a saved register on the - stack), fetch it. */ - if (value_lazy (new_val)) - value_fetch_lazy (new_val); - - /* Copy the contents and the unavailability/optimized-out - meta-data from NEW_VAL to VAL. */ - set_value_lazy (val, 0); - value_contents_copy (val, value_embedded_offset (val), - new_val, value_embedded_offset (new_val), - type_length_units (type)); - - if (frame_debug) - { - struct gdbarch *gdbarch; - struct frame_info *frame; - /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID, - so that the frame level will be shown correctly. */ - frame = frame_find_by_id (VALUE_FRAME_ID (val)); - regnum = VALUE_REGNUM (val); - gdbarch = get_frame_arch (frame); - - fprintf_unfiltered (gdb_stdlog, - "{ value_fetch_lazy " - "(frame=%d,regnum=%d(%s),...) ", - frame_relative_level (frame), regnum, - user_reg_map_regnum_to_name (gdbarch, regnum)); - - fprintf_unfiltered (gdb_stdlog, "->"); - if (value_optimized_out (new_val)) - { - fprintf_unfiltered (gdb_stdlog, " "); - val_print_optimized_out (new_val, gdb_stdlog); - } - else - { - int i; - const gdb_byte *buf = value_contents (new_val); - - if (VALUE_LVAL (new_val) == lval_register) - fprintf_unfiltered (gdb_stdlog, " register=%d", - VALUE_REGNUM (new_val)); - else if (VALUE_LVAL (new_val) == lval_memory) - fprintf_unfiltered (gdb_stdlog, " address=%s", - paddress (gdbarch, - value_address (new_val))); - else - fprintf_unfiltered (gdb_stdlog, " computed"); - - fprintf_unfiltered (gdb_stdlog, " bytes="); - fprintf_unfiltered (gdb_stdlog, "["); - for (i = 0; i < register_size (gdbarch, regnum); i++) - fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]); - fprintf_unfiltered (gdb_stdlog, "]"); - } - - fprintf_unfiltered (gdb_stdlog, " }\n"); - } - - /* Dispose of the intermediate values. This prevents - watchpoints from trying to watch the saved frame pointer. */ - value_free_to_mark (mark); - } + value_fetch_lazy_register (val); else if (VALUE_LVAL (val) == lval_computed && value_computed_funcs (val)->read != NULL) value_computed_funcs (val)->read (val); |