| /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
| |
| Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
| 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008 |
| Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "gdb_string.h" |
| #include "symtab.h" |
| #include "gdbtypes.h" |
| #include "value.h" |
| #include "gdbcore.h" |
| #include "command.h" |
| #include "gdbcmd.h" |
| #include "target.h" |
| #include "language.h" |
| #include "demangle.h" |
| #include "doublest.h" |
| #include "gdb_assert.h" |
| #include "regcache.h" |
| #include "block.h" |
| #include "dfp.h" |
| #include "objfiles.h" |
| |
| /* Prototypes for exported functions. */ |
| |
| void _initialize_values (void); |
| |
| struct value |
| { |
| /* Type of value; either not an lval, or one of the various |
| different possible kinds of lval. */ |
| enum lval_type lval; |
| |
| /* Is it modifiable? Only relevant if lval != not_lval. */ |
| int modifiable; |
| |
| /* Location of value (if lval). */ |
| union |
| { |
| /* If lval == lval_memory, this is the address in the inferior. |
| If lval == lval_register, this is the byte offset into the |
| registers structure. */ |
| CORE_ADDR address; |
| |
| /* Pointer to internal variable. */ |
| struct internalvar *internalvar; |
| } location; |
| |
| /* Describes offset of a value within lval of a structure in bytes. |
| If lval == lval_memory, this is an offset to the address. If |
| lval == lval_register, this is a further offset from |
| location.address within the registers structure. Note also the |
| member embedded_offset below. */ |
| int offset; |
| |
| /* Only used for bitfields; number of bits contained in them. */ |
| int bitsize; |
| |
| /* Only used for bitfields; position of start of field. For |
| gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For |
| gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */ |
| int bitpos; |
| |
| /* Frame register value is relative to. This will be described in |
| the lval enum above as "lval_register". */ |
| struct frame_id frame_id; |
| |
| /* Type of the value. */ |
| struct type *type; |
| |
| /* If a value represents a C++ object, then the `type' field gives |
| the object's compile-time type. If the object actually belongs |
| to some class derived from `type', perhaps with other base |
| classes and additional members, then `type' is just a subobject |
| of the real thing, and the full object is probably larger than |
| `type' would suggest. |
| |
| If `type' is a dynamic class (i.e. one with a vtable), then GDB |
| can actually determine the object's run-time type by looking at |
| the run-time type information in the vtable. When this |
| information is available, we may elect to read in the entire |
| object, for several reasons: |
| |
| - When printing the value, the user would probably rather see the |
| full object, not just the limited portion apparent from the |
| compile-time type. |
| |
| - If `type' has virtual base classes, then even printing `type' |
| alone may require reaching outside the `type' portion of the |
| object to wherever the virtual base class has been stored. |
| |
| When we store the entire object, `enclosing_type' is the run-time |
| type -- the complete object -- and `embedded_offset' is the |
| offset of `type' within that larger type, in bytes. The |
| value_contents() macro takes `embedded_offset' into account, so |
| most GDB code continues to see the `type' portion of the value, |
| just as the inferior would. |
| |
| If `type' is a pointer to an object, then `enclosing_type' is a |
| pointer to the object's run-time type, and `pointed_to_offset' is |
| the offset in bytes from the full object to the pointed-to object |
| -- that is, the value `embedded_offset' would have if we followed |
| the pointer and fetched the complete object. (I don't really see |
| the point. Why not just determine the run-time type when you |
| indirect, and avoid the special case? The contents don't matter |
| until you indirect anyway.) |
| |
| If we're not doing anything fancy, `enclosing_type' is equal to |
| `type', and `embedded_offset' is zero, so everything works |
| normally. */ |
| struct type *enclosing_type; |
| int embedded_offset; |
| int pointed_to_offset; |
| |
| /* Values are stored in a chain, so that they can be deleted easily |
| over calls to the inferior. Values assigned to internal |
| variables or put into the value history are taken off this |
| list. */ |
| struct value *next; |
| |
| /* Register number if the value is from a register. */ |
| short regnum; |
| |
| /* If zero, contents of this value are in the contents field. If |
| nonzero, contents are in inferior. If the lval field is lval_memory, |
| the contents are in inferior memory at location.address plus offset. |
| The lval field may also be lval_register. |
| |
| WARNING: This field is used by the code which handles watchpoints |
| (see breakpoint.c) to decide whether a particular value can be |
| watched by hardware watchpoints. If the lazy flag is set for |
| some member of a value chain, it is assumed that this member of |
| the chain doesn't need to be watched as part of watching the |
| value itself. This is how GDB avoids watching the entire struct |
| or array when the user wants to watch a single struct member or |
| array element. If you ever change the way lazy flag is set and |
| reset, be sure to consider this use as well! */ |
| char lazy; |
| |
| /* If nonzero, this is the value of a variable which does not |
| actually exist in the program. */ |
| char optimized_out; |
| |
| /* If value is a variable, is it initialized or not. */ |
| int initialized; |
| |
| /* Actual contents of the value. For use of this value; setting it |
| uses the stuff above. Not valid if lazy is nonzero. Target |
| byte-order. We force it to be aligned properly for any possible |
| value. Note that a value therefore extends beyond what is |
| declared here. */ |
| union |
| { |
| gdb_byte contents[1]; |
| DOUBLEST force_doublest_align; |
| LONGEST force_longest_align; |
| CORE_ADDR force_core_addr_align; |
| void *force_pointer_align; |
| } aligner; |
| /* Do not add any new members here -- contents above will trash |
| them. */ |
| }; |
| |
| /* Prototypes for local functions. */ |
| |
| static void show_values (char *, int); |
| |
| static void show_convenience (char *, int); |
| |
| |
| /* The value-history records all the values printed |
| by print commands during this session. Each chunk |
| records 60 consecutive values. The first chunk on |
| the chain records the most recent values. |
| The total number of values is in value_history_count. */ |
| |
| #define VALUE_HISTORY_CHUNK 60 |
| |
| struct value_history_chunk |
| { |
| struct value_history_chunk *next; |
| struct value *values[VALUE_HISTORY_CHUNK]; |
| }; |
| |
| /* Chain of chunks now in use. */ |
| |
| static struct value_history_chunk *value_history_chain; |
| |
| static int value_history_count; /* Abs number of last entry stored */ |
| |
| /* List of all value objects currently allocated |
| (except for those released by calls to release_value) |
| This is so they can be freed after each command. */ |
| |
| static struct value *all_values; |
| |
| /* Allocate a value that has the correct length for type TYPE. */ |
| |
| struct value * |
| allocate_value (struct type *type) |
| { |
| struct value *val; |
| struct type *atype = check_typedef (type); |
| |
| val = (struct value *) xzalloc (sizeof (struct value) + TYPE_LENGTH (atype)); |
| val->next = all_values; |
| all_values = val; |
| val->type = type; |
| val->enclosing_type = type; |
| VALUE_LVAL (val) = not_lval; |
| VALUE_ADDRESS (val) = 0; |
| VALUE_FRAME_ID (val) = null_frame_id; |
| val->offset = 0; |
| val->bitpos = 0; |
| val->bitsize = 0; |
| VALUE_REGNUM (val) = -1; |
| val->lazy = 0; |
| val->optimized_out = 0; |
| val->embedded_offset = 0; |
| val->pointed_to_offset = 0; |
| val->modifiable = 1; |
| val->initialized = 1; /* Default to initialized. */ |
| return val; |
| } |
| |
| /* Allocate a value that has the correct length |
| for COUNT repetitions of type TYPE. */ |
| |
| struct value * |
| allocate_repeat_value (struct type *type, int count) |
| { |
| int low_bound = current_language->string_lower_bound; /* ??? */ |
| /* FIXME-type-allocation: need a way to free this type when we are |
| done with it. */ |
| struct type *range_type |
| = create_range_type ((struct type *) NULL, builtin_type_int, |
| low_bound, count + low_bound - 1); |
| /* FIXME-type-allocation: need a way to free this type when we are |
| done with it. */ |
| return allocate_value (create_array_type ((struct type *) NULL, |
| type, range_type)); |
| } |
| |
| /* Accessor methods. */ |
| |
| struct value * |
| value_next (struct value *value) |
| { |
| return value->next; |
| } |
| |
| struct type * |
| value_type (struct value *value) |
| { |
| return value->type; |
| } |
| void |
| deprecated_set_value_type (struct value *value, struct type *type) |
| { |
| value->type = type; |
| } |
| |
| int |
| value_offset (struct value *value) |
| { |
| return value->offset; |
| } |
| void |
| set_value_offset (struct value *value, int offset) |
| { |
| value->offset = offset; |
| } |
| |
| int |
| value_bitpos (struct value *value) |
| { |
| return value->bitpos; |
| } |
| void |
| set_value_bitpos (struct value *value, int bit) |
| { |
| value->bitpos = bit; |
| } |
| |
| int |
| value_bitsize (struct value *value) |
| { |
| return value->bitsize; |
| } |
| void |
| set_value_bitsize (struct value *value, int bit) |
| { |
| value->bitsize = bit; |
| } |
| |
| gdb_byte * |
| value_contents_raw (struct value *value) |
| { |
| return value->aligner.contents + value->embedded_offset; |
| } |
| |
| gdb_byte * |
| value_contents_all_raw (struct value *value) |
| { |
| return value->aligner.contents; |
| } |
| |
| struct type * |
| value_enclosing_type (struct value *value) |
| { |
| return value->enclosing_type; |
| } |
| |
| const gdb_byte * |
| value_contents_all (struct value *value) |
| { |
| if (value->lazy) |
| value_fetch_lazy (value); |
| return value->aligner.contents; |
| } |
| |
| int |
| value_lazy (struct value *value) |
| { |
| return value->lazy; |
| } |
| |
| void |
| set_value_lazy (struct value *value, int val) |
| { |
| value->lazy = val; |
| } |
| |
| const gdb_byte * |
| value_contents (struct value *value) |
| { |
| return value_contents_writeable (value); |
| } |
| |
| gdb_byte * |
| value_contents_writeable (struct value *value) |
| { |
| if (value->lazy) |
| value_fetch_lazy (value); |
| return value_contents_raw (value); |
| } |
| |
| /* Return non-zero if VAL1 and VAL2 have the same contents. Note that |
| this function is different from value_equal; in C the operator == |
| can return 0 even if the two values being compared are equal. */ |
| |
| int |
| value_contents_equal (struct value *val1, struct value *val2) |
| { |
| struct type *type1; |
| struct type *type2; |
| int len; |
| |
| type1 = check_typedef (value_type (val1)); |
| type2 = check_typedef (value_type (val2)); |
| len = TYPE_LENGTH (type1); |
| if (len != TYPE_LENGTH (type2)) |
| return 0; |
| |
| return (memcmp (value_contents (val1), value_contents (val2), len) == 0); |
| } |
| |
| int |
| value_optimized_out (struct value *value) |
| { |
| return value->optimized_out; |
| } |
| |
| void |
| set_value_optimized_out (struct value *value, int val) |
| { |
| value->optimized_out = val; |
| } |
| |
| int |
| value_embedded_offset (struct value *value) |
| { |
| return value->embedded_offset; |
| } |
| |
| void |
| set_value_embedded_offset (struct value *value, int val) |
| { |
| value->embedded_offset = val; |
| } |
| |
| int |
| value_pointed_to_offset (struct value *value) |
| { |
| return value->pointed_to_offset; |
| } |
| |
| void |
| set_value_pointed_to_offset (struct value *value, int val) |
| { |
| value->pointed_to_offset = val; |
| } |
| |
| enum lval_type * |
| deprecated_value_lval_hack (struct value *value) |
| { |
| return &value->lval; |
| } |
| |
| CORE_ADDR * |
| deprecated_value_address_hack (struct value *value) |
| { |
| return &value->location.address; |
| } |
| |
| struct internalvar ** |
| deprecated_value_internalvar_hack (struct value *value) |
| { |
| return &value->location.internalvar; |
| } |
| |
| struct frame_id * |
| deprecated_value_frame_id_hack (struct value *value) |
| { |
| return &value->frame_id; |
| } |
| |
| short * |
| deprecated_value_regnum_hack (struct value *value) |
| { |
| return &value->regnum; |
| } |
| |
| int |
| deprecated_value_modifiable (struct value *value) |
| { |
| return value->modifiable; |
| } |
| void |
| deprecated_set_value_modifiable (struct value *value, int modifiable) |
| { |
| value->modifiable = modifiable; |
| } |
| |
| /* Return a mark in the value chain. All values allocated after the |
| mark is obtained (except for those released) are subject to being freed |
| if a subsequent value_free_to_mark is passed the mark. */ |
| struct value * |
| value_mark (void) |
| { |
| return all_values; |
| } |
| |
| /* Free all values allocated since MARK was obtained by value_mark |
| (except for those released). */ |
| void |
| value_free_to_mark (struct value *mark) |
| { |
| struct value *val; |
| struct value *next; |
| |
| for (val = all_values; val && val != mark; val = next) |
| { |
| next = val->next; |
| value_free (val); |
| } |
| all_values = val; |
| } |
| |
| /* Free all the values that have been allocated (except for those released). |
| Called after each command, successful or not. */ |
| |
| void |
| free_all_values (void) |
| { |
| struct value *val; |
| struct value *next; |
| |
| for (val = all_values; val; val = next) |
| { |
| next = val->next; |
| value_free (val); |
| } |
| |
| all_values = 0; |
| } |
| |
| /* Remove VAL from the chain all_values |
| so it will not be freed automatically. */ |
| |
| void |
| release_value (struct value *val) |
| { |
| struct value *v; |
| |
| if (all_values == val) |
| { |
| all_values = val->next; |
| return; |
| } |
| |
| for (v = all_values; v; v = v->next) |
| { |
| if (v->next == val) |
| { |
| v->next = val->next; |
| break; |
| } |
| } |
| } |
| |
| /* Release all values up to mark */ |
| struct value * |
| value_release_to_mark (struct value *mark) |
| { |
| struct value *val; |
| struct value *next; |
| |
| for (val = next = all_values; next; next = next->next) |
| if (next->next == mark) |
| { |
| all_values = next->next; |
| next->next = NULL; |
| return val; |
| } |
| all_values = 0; |
| return val; |
| } |
| |
| /* Return a copy of the value ARG. |
| It contains the same contents, for same memory address, |
| but it's a different block of storage. */ |
| |
| struct value * |
| value_copy (struct value *arg) |
| { |
| struct type *encl_type = value_enclosing_type (arg); |
| struct value *val = allocate_value (encl_type); |
| val->type = arg->type; |
| VALUE_LVAL (val) = VALUE_LVAL (arg); |
| val->location = arg->location; |
| val->offset = arg->offset; |
| val->bitpos = arg->bitpos; |
| val->bitsize = arg->bitsize; |
| VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg); |
| VALUE_REGNUM (val) = VALUE_REGNUM (arg); |
| val->lazy = arg->lazy; |
| val->optimized_out = arg->optimized_out; |
| val->embedded_offset = value_embedded_offset (arg); |
| val->pointed_to_offset = arg->pointed_to_offset; |
| val->modifiable = arg->modifiable; |
| if (!value_lazy (val)) |
| { |
| memcpy (value_contents_all_raw (val), value_contents_all_raw (arg), |
| TYPE_LENGTH (value_enclosing_type (arg))); |
| |
| } |
| return val; |
| } |
| |
| /* Access to the value history. */ |
| |
| /* Record a new value in the value history. |
| Returns the absolute history index of the entry. |
| Result of -1 indicates the value was not saved; otherwise it is the |
| value history index of this new item. */ |
| |
| int |
| record_latest_value (struct value *val) |
| { |
| int i; |
| |
| /* We don't want this value to have anything to do with the inferior anymore. |
| In particular, "set $1 = 50" should not affect the variable from which |
| the value was taken, and fast watchpoints should be able to assume that |
| a value on the value history never changes. */ |
| if (value_lazy (val)) |
| value_fetch_lazy (val); |
| /* We preserve VALUE_LVAL so that the user can find out where it was fetched |
| from. This is a bit dubious, because then *&$1 does not just return $1 |
| but the current contents of that location. c'est la vie... */ |
| val->modifiable = 0; |
| release_value (val); |
| |
| /* Here we treat value_history_count as origin-zero |
| and applying to the value being stored now. */ |
| |
| i = value_history_count % VALUE_HISTORY_CHUNK; |
| if (i == 0) |
| { |
| struct value_history_chunk *new |
| = (struct value_history_chunk *) |
| xmalloc (sizeof (struct value_history_chunk)); |
| memset (new->values, 0, sizeof new->values); |
| new->next = value_history_chain; |
| value_history_chain = new; |
| } |
| |
| value_history_chain->values[i] = val; |
| |
| /* Now we regard value_history_count as origin-one |
| and applying to the value just stored. */ |
| |
| return ++value_history_count; |
| } |
| |
| /* Return a copy of the value in the history with sequence number NUM. */ |
| |
| struct value * |
| access_value_history (int num) |
| { |
| struct value_history_chunk *chunk; |
| int i; |
| int absnum = num; |
| |
| if (absnum <= 0) |
| absnum += value_history_count; |
| |
| if (absnum <= 0) |
| { |
| if (num == 0) |
| error (_("The history is empty.")); |
| else if (num == 1) |
| error (_("There is only one value in the history.")); |
| else |
| error (_("History does not go back to $$%d."), -num); |
| } |
| if (absnum > value_history_count) |
| error (_("History has not yet reached $%d."), absnum); |
| |
| absnum--; |
| |
| /* Now absnum is always absolute and origin zero. */ |
| |
| chunk = value_history_chain; |
| for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; |
| i > 0; i--) |
| chunk = chunk->next; |
| |
| return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); |
| } |
| |
| static void |
| show_values (char *num_exp, int from_tty) |
| { |
| int i; |
| struct value *val; |
| static int num = 1; |
| |
| if (num_exp) |
| { |
| /* "show values +" should print from the stored position. |
| "show values <exp>" should print around value number <exp>. */ |
| if (num_exp[0] != '+' || num_exp[1] != '\0') |
| num = parse_and_eval_long (num_exp) - 5; |
| } |
| else |
| { |
| /* "show values" means print the last 10 values. */ |
| num = value_history_count - 9; |
| } |
| |
| if (num <= 0) |
| num = 1; |
| |
| for (i = num; i < num + 10 && i <= value_history_count; i++) |
| { |
| val = access_value_history (i); |
| printf_filtered (("$%d = "), i); |
| value_print (val, gdb_stdout, 0, Val_pretty_default); |
| printf_filtered (("\n")); |
| } |
| |
| /* The next "show values +" should start after what we just printed. */ |
| num += 10; |
| |
| /* Hitting just return after this command should do the same thing as |
| "show values +". If num_exp is null, this is unnecessary, since |
| "show values +" is not useful after "show values". */ |
| if (from_tty && num_exp) |
| { |
| num_exp[0] = '+'; |
| num_exp[1] = '\0'; |
| } |
| } |
| |
| /* Internal variables. These are variables within the debugger |
| that hold values assigned by debugger commands. |
| The user refers to them with a '$' prefix |
| that does not appear in the variable names stored internally. */ |
| |
| static struct internalvar *internalvars; |
| |
| /* If the variable does not already exist create it and give it the value given. |
| If no value is given then the default is zero. */ |
| static void |
| init_if_undefined_command (char* args, int from_tty) |
| { |
| struct internalvar* intvar; |
| |
| /* Parse the expression - this is taken from set_command(). */ |
| struct expression *expr = parse_expression (args); |
| register struct cleanup *old_chain = |
| make_cleanup (free_current_contents, &expr); |
| |
| /* Validate the expression. |
| Was the expression an assignment? |
| Or even an expression at all? */ |
| if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN) |
| error (_("Init-if-undefined requires an assignment expression.")); |
| |
| /* Extract the variable from the parsed expression. |
| In the case of an assign the lvalue will be in elts[1] and elts[2]. */ |
| if (expr->elts[1].opcode != OP_INTERNALVAR) |
| error (_("The first parameter to init-if-undefined should be a GDB variable.")); |
| intvar = expr->elts[2].internalvar; |
| |
| /* Only evaluate the expression if the lvalue is void. |
| This may still fail if the expresssion is invalid. */ |
| if (TYPE_CODE (value_type (intvar->value)) == TYPE_CODE_VOID) |
| evaluate_expression (expr); |
| |
| do_cleanups (old_chain); |
| } |
| |
| |
| /* Look up an internal variable with name NAME. NAME should not |
| normally include a dollar sign. |
| |
| If the specified internal variable does not exist, |
| the return value is NULL. */ |
| |
| struct internalvar * |
| lookup_only_internalvar (char *name) |
| { |
| struct internalvar *var; |
| |
| for (var = internalvars; var; var = var->next) |
| if (strcmp (var->name, name) == 0) |
| return var; |
| |
| return NULL; |
| } |
| |
| |
| /* Create an internal variable with name NAME and with a void value. |
| NAME should not normally include a dollar sign. */ |
| |
| struct internalvar * |
| create_internalvar (char *name) |
| { |
| struct internalvar *var; |
| var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); |
| var->name = concat (name, (char *)NULL); |
| var->value = allocate_value (builtin_type_void); |
| var->endian = gdbarch_byte_order (current_gdbarch); |
| release_value (var->value); |
| var->next = internalvars; |
| internalvars = var; |
| return var; |
| } |
| |
| |
| /* Look up an internal variable with name NAME. NAME should not |
| normally include a dollar sign. |
| |
| If the specified internal variable does not exist, |
| one is created, with a void value. */ |
| |
| struct internalvar * |
| lookup_internalvar (char *name) |
| { |
| struct internalvar *var; |
| |
| var = lookup_only_internalvar (name); |
| if (var) |
| return var; |
| |
| return create_internalvar (name); |
| } |
| |
| struct value * |
| value_of_internalvar (struct internalvar *var) |
| { |
| struct value *val; |
| int i, j; |
| gdb_byte temp; |
| |
| val = value_copy (var->value); |
| if (value_lazy (val)) |
| value_fetch_lazy (val); |
| VALUE_LVAL (val) = lval_internalvar; |
| VALUE_INTERNALVAR (val) = var; |
| |
| /* Values are always stored in the target's byte order. When connected to a |
| target this will most likely always be correct, so there's normally no |
| need to worry about it. |
| |
| However, internal variables can be set up before the target endian is |
| known and so may become out of date. Fix it up before anybody sees. |
| |
| Internal variables usually hold simple scalar values, and we can |
| correct those. More complex values (e.g. structures and floating |
| point types) are left alone, because they would be too complicated |
| to correct. */ |
| |
| if (var->endian != gdbarch_byte_order (current_gdbarch)) |
| { |
| gdb_byte *array = value_contents_raw (val); |
| struct type *type = check_typedef (value_enclosing_type (val)); |
| switch (TYPE_CODE (type)) |
| { |
| case TYPE_CODE_INT: |
| case TYPE_CODE_PTR: |
| /* Reverse the bytes. */ |
| for (i = 0, j = TYPE_LENGTH (type) - 1; i < j; i++, j--) |
| { |
| temp = array[j]; |
| array[j] = array[i]; |
| array[i] = temp; |
| } |
| break; |
| } |
| } |
| |
| return val; |
| } |
| |
| void |
| set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
| int bitsize, struct value *newval) |
| { |
| gdb_byte *addr = value_contents_writeable (var->value) + offset; |
| |
| if (bitsize) |
| modify_field (addr, value_as_long (newval), |
| bitpos, bitsize); |
| else |
| memcpy (addr, value_contents (newval), TYPE_LENGTH (value_type (newval))); |
| } |
| |
| void |
| set_internalvar (struct internalvar *var, struct value *val) |
| { |
| struct value *newval; |
| |
| newval = value_copy (val); |
| newval->modifiable = 1; |
| |
| /* Force the value to be fetched from the target now, to avoid problems |
| later when this internalvar is referenced and the target is gone or |
| has changed. */ |
| if (value_lazy (newval)) |
| value_fetch_lazy (newval); |
| |
| /* Begin code which must not call error(). If var->value points to |
| something free'd, an error() obviously leaves a dangling pointer. |
| But we also get a danling pointer if var->value points to |
| something in the value chain (i.e., before release_value is |
| called), because after the error free_all_values will get called before |
| long. */ |
| xfree (var->value); |
| var->value = newval; |
| var->endian = gdbarch_byte_order (current_gdbarch); |
| release_value (newval); |
| /* End code which must not call error(). */ |
| } |
| |
| char * |
| internalvar_name (struct internalvar *var) |
| { |
| return var->name; |
| } |
| |
| /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to |
| prevent cycles / duplicates. */ |
| |
| static void |
| preserve_one_value (struct value *value, struct objfile *objfile, |
| htab_t copied_types) |
| { |
| if (TYPE_OBJFILE (value->type) == objfile) |
| value->type = copy_type_recursive (objfile, value->type, copied_types); |
| |
| if (TYPE_OBJFILE (value->enclosing_type) == objfile) |
| value->enclosing_type = copy_type_recursive (objfile, |
| value->enclosing_type, |
| copied_types); |
| } |
| |
| /* Update the internal variables and value history when OBJFILE is |
| discarded; we must copy the types out of the objfile. New global types |
| will be created for every convenience variable which currently points to |
| this objfile's types, and the convenience variables will be adjusted to |
| use the new global types. */ |
| |
| void |
| preserve_values (struct objfile *objfile) |
| { |
| htab_t copied_types; |
| struct value_history_chunk *cur; |
| struct internalvar *var; |
| int i; |
| |
| /* Create the hash table. We allocate on the objfile's obstack, since |
| it is soon to be deleted. */ |
| copied_types = create_copied_types_hash (objfile); |
| |
| for (cur = value_history_chain; cur; cur = cur->next) |
| for (i = 0; i < VALUE_HISTORY_CHUNK; i++) |
| if (cur->values[i]) |
| preserve_one_value (cur->values[i], objfile, copied_types); |
| |
| for (var = internalvars; var; var = var->next) |
| preserve_one_value (var->value, objfile, copied_types); |
| |
| htab_delete (copied_types); |
| } |
| |
| static void |
| show_convenience (char *ignore, int from_tty) |
| { |
| struct internalvar *var; |
| int varseen = 0; |
| |
| for (var = internalvars; var; var = var->next) |
| { |
| if (!varseen) |
| { |
| varseen = 1; |
| } |
| printf_filtered (("$%s = "), var->name); |
| value_print (value_of_internalvar (var), gdb_stdout, |
| 0, Val_pretty_default); |
| printf_filtered (("\n")); |
| } |
| if (!varseen) |
| printf_unfiltered (_("\ |
| No debugger convenience variables now defined.\n\ |
| Convenience variables have names starting with \"$\";\n\ |
| use \"set\" as in \"set $foo = 5\" to define them.\n")); |
| } |
| |
| /* Extract a value as a C number (either long or double). |
| Knows how to convert fixed values to double, or |
| floating values to long. |
| Does not deallocate the value. */ |
| |
| LONGEST |
| value_as_long (struct value *val) |
| { |
| /* This coerces arrays and functions, which is necessary (e.g. |
| in disassemble_command). It also dereferences references, which |
| I suspect is the most logical thing to do. */ |
| val = coerce_array (val); |
| return unpack_long (value_type (val), value_contents (val)); |
| } |
| |
| DOUBLEST |
| value_as_double (struct value *val) |
| { |
| DOUBLEST foo; |
| int inv; |
| |
| foo = unpack_double (value_type (val), value_contents (val), &inv); |
| if (inv) |
| error (_("Invalid floating value found in program.")); |
| return foo; |
| } |
| |
| /* Extract a value as a C pointer. Does not deallocate the value. |
| Note that val's type may not actually be a pointer; value_as_long |
| handles all the cases. */ |
| CORE_ADDR |
| value_as_address (struct value *val) |
| { |
| /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| whether we want this to be true eventually. */ |
| #if 0 |
| /* gdbarch_addr_bits_remove is wrong if we are being called for a |
| non-address (e.g. argument to "signal", "info break", etc.), or |
| for pointers to char, in which the low bits *are* significant. */ |
| return gdbarch_addr_bits_remove (current_gdbarch, value_as_long (val)); |
| #else |
| |
| /* There are several targets (IA-64, PowerPC, and others) which |
| don't represent pointers to functions as simply the address of |
| the function's entry point. For example, on the IA-64, a |
| function pointer points to a two-word descriptor, generated by |
| the linker, which contains the function's entry point, and the |
| value the IA-64 "global pointer" register should have --- to |
| support position-independent code. The linker generates |
| descriptors only for those functions whose addresses are taken. |
| |
| On such targets, it's difficult for GDB to convert an arbitrary |
| function address into a function pointer; it has to either find |
| an existing descriptor for that function, or call malloc and |
| build its own. On some targets, it is impossible for GDB to |
| build a descriptor at all: the descriptor must contain a jump |
| instruction; data memory cannot be executed; and code memory |
| cannot be modified. |
| |
| Upon entry to this function, if VAL is a value of type `function' |
| (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then |
| VALUE_ADDRESS (val) is the address of the function. This is what |
| you'll get if you evaluate an expression like `main'. The call |
| to COERCE_ARRAY below actually does all the usual unary |
| conversions, which includes converting values of type `function' |
| to `pointer to function'. This is the challenging conversion |
| discussed above. Then, `unpack_long' will convert that pointer |
| back into an address. |
| |
| So, suppose the user types `disassemble foo' on an architecture |
| with a strange function pointer representation, on which GDB |
| cannot build its own descriptors, and suppose further that `foo' |
| has no linker-built descriptor. The address->pointer conversion |
| will signal an error and prevent the command from running, even |
| though the next step would have been to convert the pointer |
| directly back into the same address. |
| |
| The following shortcut avoids this whole mess. If VAL is a |
| function, just return its address directly. */ |
| if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC |
| || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD) |
| return VALUE_ADDRESS (val); |
| |
| val = coerce_array (val); |
| |
| /* Some architectures (e.g. Harvard), map instruction and data |
| addresses onto a single large unified address space. For |
| instance: An architecture may consider a large integer in the |
| range 0x10000000 .. 0x1000ffff to already represent a data |
| addresses (hence not need a pointer to address conversion) while |
| a small integer would still need to be converted integer to |
| pointer to address. Just assume such architectures handle all |
| integer conversions in a single function. */ |
| |
| /* JimB writes: |
| |
| I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we |
| must admonish GDB hackers to make sure its behavior matches the |
| compiler's, whenever possible. |
| |
| In general, I think GDB should evaluate expressions the same way |
| the compiler does. When the user copies an expression out of |
| their source code and hands it to a `print' command, they should |
| get the same value the compiler would have computed. Any |
| deviation from this rule can cause major confusion and annoyance, |
| and needs to be justified carefully. In other words, GDB doesn't |
| really have the freedom to do these conversions in clever and |
| useful ways. |
| |
| AndrewC pointed out that users aren't complaining about how GDB |
| casts integers to pointers; they are complaining that they can't |
| take an address from a disassembly listing and give it to `x/i'. |
| This is certainly important. |
| |
| Adding an architecture method like integer_to_address() certainly |
| makes it possible for GDB to "get it right" in all circumstances |
| --- the target has complete control over how things get done, so |
| people can Do The Right Thing for their target without breaking |
| anyone else. The standard doesn't specify how integers get |
| converted to pointers; usually, the ABI doesn't either, but |
| ABI-specific code is a more reasonable place to handle it. */ |
| |
| if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR |
| && TYPE_CODE (value_type (val)) != TYPE_CODE_REF |
| && gdbarch_integer_to_address_p (current_gdbarch)) |
| return gdbarch_integer_to_address (current_gdbarch, value_type (val), |
| value_contents (val)); |
| |
| return unpack_long (value_type (val), value_contents (val)); |
| #endif |
| } |
| |
| /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| as a long, or as a double, assuming the raw data is described |
| by type TYPE. Knows how to convert different sizes of values |
| and can convert between fixed and floating point. We don't assume |
| any alignment for the raw data. Return value is in host byte order. |
| |
| If you want functions and arrays to be coerced to pointers, and |
| references to be dereferenced, call value_as_long() instead. |
| |
| C++: It is assumed that the front-end has taken care of |
| all matters concerning pointers to members. A pointer |
| to member which reaches here is considered to be equivalent |
| to an INT (or some size). After all, it is only an offset. */ |
| |
| LONGEST |
| unpack_long (struct type *type, const gdb_byte *valaddr) |
| { |
| enum type_code code = TYPE_CODE (type); |
| int len = TYPE_LENGTH (type); |
| int nosign = TYPE_UNSIGNED (type); |
| |
| switch (code) |
| { |
| case TYPE_CODE_TYPEDEF: |
| return unpack_long (check_typedef (type), valaddr); |
| case TYPE_CODE_ENUM: |
| case TYPE_CODE_FLAGS: |
| case TYPE_CODE_BOOL: |
| case TYPE_CODE_INT: |
| case TYPE_CODE_CHAR: |
| case TYPE_CODE_RANGE: |
| case TYPE_CODE_MEMBERPTR: |
| if (nosign) |
| return extract_unsigned_integer (valaddr, len); |
| else |
| return extract_signed_integer (valaddr, len); |
| |
| case TYPE_CODE_FLT: |
| return extract_typed_floating (valaddr, type); |
| |
| case TYPE_CODE_DECFLOAT: |
| /* libdecnumber has a function to convert from decimal to integer, but |
| it doesn't work when the decimal number has a fractional part. */ |
| return decimal_to_doublest (valaddr, len); |
| |
| case TYPE_CODE_PTR: |
| case TYPE_CODE_REF: |
| /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| whether we want this to be true eventually. */ |
| return extract_typed_address (valaddr, type); |
| |
| default: |
| error (_("Value can't be converted to integer.")); |
| } |
| return 0; /* Placate lint. */ |
| } |
| |
| /* Return a double value from the specified type and address. |
| INVP points to an int which is set to 0 for valid value, |
| 1 for invalid value (bad float format). In either case, |
| the returned double is OK to use. Argument is in target |
| format, result is in host format. */ |
| |
| DOUBLEST |
| unpack_double (struct type *type, const gdb_byte *valaddr, int *invp) |
| { |
| enum type_code code; |
| int len; |
| int nosign; |
| |
| *invp = 0; /* Assume valid. */ |
| CHECK_TYPEDEF (type); |
| code = TYPE_CODE (type); |
| len = TYPE_LENGTH (type); |
| nosign = TYPE_UNSIGNED (type); |
| if (code == TYPE_CODE_FLT) |
| { |
| /* NOTE: cagney/2002-02-19: There was a test here to see if the |
| floating-point value was valid (using the macro |
| INVALID_FLOAT). That test/macro have been removed. |
| |
| It turns out that only the VAX defined this macro and then |
| only in a non-portable way. Fixing the portability problem |
| wouldn't help since the VAX floating-point code is also badly |
| bit-rotten. The target needs to add definitions for the |
| methods gdbarch_float_format and gdbarch_double_format - these |
| exactly describe the target floating-point format. The |
| problem here is that the corresponding floatformat_vax_f and |
| floatformat_vax_d values these methods should be set to are |
| also not defined either. Oops! |
| |
| Hopefully someone will add both the missing floatformat |
| definitions and the new cases for floatformat_is_valid (). */ |
| |
| if (!floatformat_is_valid (floatformat_from_type (type), valaddr)) |
| { |
| *invp = 1; |
| return 0.0; |
| } |
| |
| return extract_typed_floating (valaddr, type); |
| } |
| else if (code == TYPE_CODE_DECFLOAT) |
| return decimal_to_doublest (valaddr, len); |
| else if (nosign) |
| { |
| /* Unsigned -- be sure we compensate for signed LONGEST. */ |
| return (ULONGEST) unpack_long (type, valaddr); |
| } |
| else |
| { |
| /* Signed -- we are OK with unpack_long. */ |
| return unpack_long (type, valaddr); |
| } |
| } |
| |
| /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| as a CORE_ADDR, assuming the raw data is described by type TYPE. |
| We don't assume any alignment for the raw data. Return value is in |
| host byte order. |
| |
| If you want functions and arrays to be coerced to pointers, and |
| references to be dereferenced, call value_as_address() instead. |
| |
| C++: It is assumed that the front-end has taken care of |
| all matters concerning pointers to members. A pointer |
| to member which reaches here is considered to be equivalent |
| to an INT (or some size). After all, it is only an offset. */ |
| |
| CORE_ADDR |
| unpack_pointer (struct type *type, const gdb_byte *valaddr) |
| { |
| /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| whether we want this to be true eventually. */ |
| return unpack_long (type, valaddr); |
| } |
| |
| |
| /* Get the value of the FIELDN'th field (which must be static) of |
| TYPE. Return NULL if the field doesn't exist or has been |
| optimized out. */ |
| |
| struct value * |
| value_static_field (struct type *type, int fieldno) |
| { |
| struct value *retval; |
| |
| if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno)) |
| { |
| retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
| TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
| } |
| else |
| { |
| char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); |
| struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0); |
| if (sym == NULL) |
| { |
| /* With some compilers, e.g. HP aCC, static data members are reported |
| as non-debuggable symbols */ |
| struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); |
| if (!msym) |
| return NULL; |
| else |
| { |
| retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
| SYMBOL_VALUE_ADDRESS (msym)); |
| } |
| } |
| else |
| { |
| /* SYM should never have a SYMBOL_CLASS which will require |
| read_var_value to use the FRAME parameter. */ |
| if (symbol_read_needs_frame (sym)) |
| warning (_("static field's value depends on the current " |
| "frame - bad debug info?")); |
| retval = read_var_value (sym, NULL); |
| } |
| if (retval && VALUE_LVAL (retval) == lval_memory) |
| SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), |
| VALUE_ADDRESS (retval)); |
| } |
| return retval; |
| } |
| |
| /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
| You have to be careful here, since the size of the data area for the value |
| is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger |
| than the old enclosing type, you have to allocate more space for the data. |
| The return value is a pointer to the new version of this value structure. */ |
| |
| struct value * |
| value_change_enclosing_type (struct value *val, struct type *new_encl_type) |
| { |
| if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (value_enclosing_type (val))) |
| { |
| val->enclosing_type = new_encl_type; |
| return val; |
| } |
| else |
| { |
| struct value *new_val; |
| struct value *prev; |
| |
| new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type)); |
| |
| new_val->enclosing_type = new_encl_type; |
| |
| /* We have to make sure this ends up in the same place in the value |
| chain as the original copy, so it's clean-up behavior is the same. |
| If the value has been released, this is a waste of time, but there |
| is no way to tell that in advance, so... */ |
| |
| if (val != all_values) |
| { |
| for (prev = all_values; prev != NULL; prev = prev->next) |
| { |
| if (prev->next == val) |
| { |
| prev->next = new_val; |
| break; |
| } |
| } |
| } |
| |
| return new_val; |
| } |
| } |
| |
| /* Given a value ARG1 (offset by OFFSET bytes) |
| of a struct or union type ARG_TYPE, |
| extract and return the value of one of its (non-static) fields. |
| FIELDNO says which field. */ |
| |
| struct value * |
| value_primitive_field (struct value *arg1, int offset, |
| int fieldno, struct type *arg_type) |
| { |
| struct value *v; |
| struct type *type; |
| |
| CHECK_TYPEDEF (arg_type); |
| type = TYPE_FIELD_TYPE (arg_type, fieldno); |
| |
| /* Handle packed fields */ |
| |
| if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) |
| { |
| v = value_from_longest (type, |
| unpack_field_as_long (arg_type, |
| value_contents (arg1) |
| + offset, |
| fieldno)); |
| v->bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; |
| v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno); |
| v->offset = value_offset (arg1) + offset |
| + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
| } |
| else if (fieldno < TYPE_N_BASECLASSES (arg_type)) |
| { |
| /* This field is actually a base subobject, so preserve the |
| entire object's contents for later references to virtual |
| bases, etc. */ |
| v = allocate_value (value_enclosing_type (arg1)); |
| v->type = type; |
| if (VALUE_LVAL (arg1) == lval_memory && value_lazy (arg1)) |
| set_value_lazy (v, 1); |
| else |
| memcpy (value_contents_all_raw (v), value_contents_all_raw (arg1), |
| TYPE_LENGTH (value_enclosing_type (arg1))); |
| v->offset = value_offset (arg1); |
| v->embedded_offset = (offset + value_embedded_offset (arg1) |
| + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8); |
| } |
| else |
| { |
| /* Plain old data member */ |
| offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
| v = allocate_value (type); |
| if (VALUE_LVAL (arg1) == lval_memory && value_lazy (arg1)) |
| set_value_lazy (v, 1); |
| else |
| memcpy (value_contents_raw (v), |
| value_contents_raw (arg1) + offset, |
| TYPE_LENGTH (type)); |
| v->offset = (value_offset (arg1) + offset |
| + value_embedded_offset (arg1)); |
| } |
| VALUE_LVAL (v) = VALUE_LVAL (arg1); |
| if (VALUE_LVAL (arg1) == lval_internalvar) |
| VALUE_LVAL (v) = lval_internalvar_component; |
| v->location = arg1->location; |
| VALUE_REGNUM (v) = VALUE_REGNUM (arg1); |
| VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1); |
| return v; |
| } |
| |
| /* Given a value ARG1 of a struct or union type, |
| extract and return the value of one of its (non-static) fields. |
| FIELDNO says which field. */ |
| |
| struct value * |
| value_field (struct value *arg1, int fieldno) |
| { |
| return value_primitive_field (arg1, 0, fieldno, value_type (arg1)); |
| } |
| |
| /* Return a non-virtual function as a value. |
| F is the list of member functions which contains the desired method. |
| J is an index into F which provides the desired method. |
| |
| We only use the symbol for its address, so be happy with either a |
| full symbol or a minimal symbol. |
| */ |
| |
| struct value * |
| value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type, |
| int offset) |
| { |
| struct value *v; |
| struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
| char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
| struct symbol *sym; |
| struct minimal_symbol *msym; |
| |
| sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0); |
| if (sym != NULL) |
| { |
| msym = NULL; |
| } |
| else |
| { |
| gdb_assert (sym == NULL); |
| msym = lookup_minimal_symbol (physname, NULL, NULL); |
| if (msym == NULL) |
| return NULL; |
| } |
| |
| v = allocate_value (ftype); |
| if (sym) |
| { |
| VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); |
| } |
| else |
| { |
| /* The minimal symbol might point to a function descriptor; |
| resolve it to the actual code address instead. */ |
| struct objfile *objfile = msymbol_objfile (msym); |
| struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| |
| VALUE_ADDRESS (v) |
| = gdbarch_convert_from_func_ptr_addr |
| (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target); |
| } |
| |
| if (arg1p) |
| { |
| if (type != value_type (*arg1p)) |
| *arg1p = value_ind (value_cast (lookup_pointer_type (type), |
| value_addr (*arg1p))); |
| |
| /* Move the `this' pointer according to the offset. |
| VALUE_OFFSET (*arg1p) += offset; |
| */ |
| } |
| |
| return v; |
| } |
| |
| |
| /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at |
| VALADDR. |
| |
| Extracting bits depends on endianness of the machine. Compute the |
| number of least significant bits to discard. For big endian machines, |
| we compute the total number of bits in the anonymous object, subtract |
| off the bit count from the MSB of the object to the MSB of the |
| bitfield, then the size of the bitfield, which leaves the LSB discard |
| count. For little endian machines, the discard count is simply the |
| number of bits from the LSB of the anonymous object to the LSB of the |
| bitfield. |
| |
| If the field is signed, we also do sign extension. */ |
| |
| LONGEST |
| unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno) |
| { |
| ULONGEST val; |
| ULONGEST valmask; |
| int bitpos = TYPE_FIELD_BITPOS (type, fieldno); |
| int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); |
| int lsbcount; |
| struct type *field_type; |
| |
| val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); |
| field_type = TYPE_FIELD_TYPE (type, fieldno); |
| CHECK_TYPEDEF (field_type); |
| |
| /* Extract bits. See comment above. */ |
| |
| if (gdbarch_bits_big_endian (current_gdbarch)) |
| lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); |
| else |
| lsbcount = (bitpos % 8); |
| val >>= lsbcount; |
| |
| /* If the field does not entirely fill a LONGEST, then zero the sign bits. |
| If the field is signed, and is negative, then sign extend. */ |
| |
| if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) |
| { |
| valmask = (((ULONGEST) 1) << bitsize) - 1; |
| val &= valmask; |
| if (!TYPE_UNSIGNED (field_type)) |
| { |
| if (val & (valmask ^ (valmask >> 1))) |
| { |
| val |= ~valmask; |
| } |
| } |
| } |
| return (val); |
| } |
| |
| /* Modify the value of a bitfield. ADDR points to a block of memory in |
| target byte order; the bitfield starts in the byte pointed to. FIELDVAL |
| is the desired value of the field, in host byte order. BITPOS and BITSIZE |
| indicate which bits (in target bit order) comprise the bitfield. |
| Requires 0 < BITSIZE <= lbits, 0 <= BITPOS+BITSIZE <= lbits, and |
| 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */ |
| |
| void |
| modify_field (gdb_byte *addr, LONGEST fieldval, int bitpos, int bitsize) |
| { |
| ULONGEST oword; |
| ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize); |
| |
| /* If a negative fieldval fits in the field in question, chop |
| off the sign extension bits. */ |
| if ((~fieldval & ~(mask >> 1)) == 0) |
| fieldval &= mask; |
| |
| /* Warn if value is too big to fit in the field in question. */ |
| if (0 != (fieldval & ~mask)) |
| { |
| /* FIXME: would like to include fieldval in the message, but |
| we don't have a sprintf_longest. */ |
| warning (_("Value does not fit in %d bits."), bitsize); |
| |
| /* Truncate it, otherwise adjoining fields may be corrupted. */ |
| fieldval &= mask; |
| } |
| |
| oword = extract_unsigned_integer (addr, sizeof oword); |
| |
| /* Shifting for bit field depends on endianness of the target machine. */ |
| if (gdbarch_bits_big_endian (current_gdbarch)) |
| bitpos = sizeof (oword) * 8 - bitpos - bitsize; |
| |
| oword &= ~(mask << bitpos); |
| oword |= fieldval << bitpos; |
| |
| store_unsigned_integer (addr, sizeof oword, oword); |
| } |
| |
| /* Pack NUM into BUF using a target format of TYPE. */ |
| |
| void |
| pack_long (gdb_byte *buf, struct type *type, LONGEST num) |
| { |
| int len; |
| |
| type = check_typedef (type); |
| len = TYPE_LENGTH (type); |
| |
| switch (TYPE_CODE (type)) |
| { |
| case TYPE_CODE_INT: |
| case TYPE_CODE_CHAR: |
| case TYPE_CODE_ENUM: |
| case TYPE_CODE_FLAGS: |
| case TYPE_CODE_BOOL: |
| case TYPE_CODE_RANGE: |
| case TYPE_CODE_MEMBERPTR: |
| store_signed_integer (buf, len, num); |
| break; |
| |
| case TYPE_CODE_REF: |
| case TYPE_CODE_PTR: |
| store_typed_address (buf, type, (CORE_ADDR) num); |
| break; |
| |
| default: |
| error (_("Unexpected type (%d) encountered for integer constant."), |
| TYPE_CODE (type)); |
| } |
| } |
| |
| |
| /* Convert C numbers into newly allocated values. */ |
| |
| struct value * |
| value_from_longest (struct type *type, LONGEST num) |
| { |
| struct value *val = allocate_value (type); |
| |
| pack_long (value_contents_raw (val), type, num); |
| |
| return val; |
| } |
| |
| |
| /* Create a value representing a pointer of type TYPE to the address |
| ADDR. */ |
| struct value * |
| value_from_pointer (struct type *type, CORE_ADDR addr) |
| { |
| struct value *val = allocate_value (type); |
| store_typed_address (value_contents_raw (val), type, addr); |
| return val; |
| } |
| |
| |
| /* Create a value for a string constant to be stored locally |
| (not in the inferior's memory space, but in GDB memory). |
| This is analogous to value_from_longest, which also does not |
| use inferior memory. String shall NOT contain embedded nulls. */ |
| |
| struct value * |
| value_from_string (char *ptr) |
| { |
| struct value *val; |
| int len = strlen (ptr); |
| int lowbound = current_language->string_lower_bound; |
| struct type *string_char_type; |
| struct type *rangetype; |
| struct type *stringtype; |
| |
| rangetype = create_range_type ((struct type *) NULL, |
| builtin_type_int, |
| lowbound, len + lowbound - 1); |
| string_char_type = language_string_char_type (current_language, |
| current_gdbarch); |
| stringtype = create_array_type ((struct type *) NULL, |
| string_char_type, |
| rangetype); |
| val = allocate_value (stringtype); |
| memcpy (value_contents_raw (val), ptr, len); |
| return val; |
| } |
| |
| struct value * |
| value_from_double (struct type *type, DOUBLEST num) |
| { |
| struct value *val = allocate_value (type); |
| struct type *base_type = check_typedef (type); |
| enum type_code code = TYPE_CODE (base_type); |
| int len = TYPE_LENGTH (base_type); |
| |
| if (code == TYPE_CODE_FLT) |
| { |
| store_typed_floating (value_contents_raw (val), base_type, num); |
| } |
| else |
| error (_("Unexpected type encountered for floating constant.")); |
| |
| return val; |
| } |
| |
| struct value * |
| value_from_decfloat (struct type *type, const gdb_byte *dec) |
| { |
| struct value *val = allocate_value (type); |
| |
| memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type)); |
| |
| return val; |
| } |
| |
| struct value * |
| coerce_ref (struct value *arg) |
| { |
| struct type *value_type_arg_tmp = check_typedef (value_type (arg)); |
| if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) |
| arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), |
| unpack_pointer (value_type (arg), |
| value_contents (arg))); |
| return arg; |
| } |
| |
| struct value * |
| coerce_array (struct value *arg) |
| { |
| arg = coerce_ref (arg); |
| if (current_language->c_style_arrays |
| && TYPE_CODE (value_type (arg)) == TYPE_CODE_ARRAY) |
| arg = value_coerce_array (arg); |
| if (TYPE_CODE (value_type (arg)) == TYPE_CODE_FUNC) |
| arg = value_coerce_function (arg); |
| return arg; |
| } |
| |
| struct value * |
| coerce_number (struct value *arg) |
| { |
| arg = coerce_array (arg); |
| arg = coerce_enum (arg); |
| return arg; |
| } |
| |
| struct value * |
| coerce_enum (struct value *arg) |
| { |
| if (TYPE_CODE (check_typedef (value_type (arg))) == TYPE_CODE_ENUM) |
| arg = value_cast (builtin_type_unsigned_int, arg); |
| return arg; |
| } |
| |
| |
| /* Return true if the function returning the specified type is using |
| the convention of returning structures in memory (passing in the |
| address as a hidden first parameter). */ |
| |
| int |
| using_struct_return (struct type *func_type, struct type *value_type) |
| { |
| enum type_code code = TYPE_CODE (value_type); |
| |
| if (code == TYPE_CODE_ERROR) |
| error (_("Function return type unknown.")); |
| |
| if (code == TYPE_CODE_VOID) |
| /* A void return value is never in memory. See also corresponding |
| code in "print_return_value". */ |
| return 0; |
| |
| /* Probe the architecture for the return-value convention. */ |
| return (gdbarch_return_value (current_gdbarch, func_type, value_type, |
| NULL, NULL, NULL) |
| != RETURN_VALUE_REGISTER_CONVENTION); |
| } |
| |
| /* Set the initialized field in a value struct. */ |
| |
| void |
| set_value_initialized (struct value *val, int status) |
| { |
| val->initialized = status; |
| } |
| |
| /* Return the initialized field in a value struct. */ |
| |
| int |
| value_initialized (struct value *val) |
| { |
| return val->initialized; |
| } |
| |
| void |
| _initialize_values (void) |
| { |
| add_cmd ("convenience", no_class, show_convenience, _("\ |
| Debugger convenience (\"$foo\") variables.\n\ |
| These variables are created when you assign them values;\n\ |
| thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\ |
| \n\ |
| A few convenience variables are given values automatically:\n\ |
| \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ |
| \"$__\" holds the contents of the last address examined with \"x\"."), |
| &showlist); |
| |
| add_cmd ("values", no_class, show_values, |
| _("Elements of value history around item number IDX (or last ten)."), |
| &showlist); |
| |
| add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\ |
| Initialize a convenience variable if necessary.\n\ |
| init-if-undefined VARIABLE = EXPRESSION\n\ |
| Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\ |
| exist or does not contain a value. The EXPRESSION is not evaluated if the\n\ |
| VARIABLE is already initialized.")); |
| } |