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Diffstat (limited to 'gdb/values.c')
| -rw-r--r-- | gdb/values.c | 1424 |
1 files changed, 0 insertions, 1424 deletions
diff --git a/gdb/values.c b/gdb/values.c deleted file mode 100644 index 9445d9c4561..00000000000 --- a/gdb/values.c +++ /dev/null @@ -1,1424 +0,0 @@ -/* Low level packing and unpacking of values for GDB, the GNU Debugger. - Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, - 1995, 1996, 1997, 1998, 1999, 2000, 2002. - 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 2 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, write to the Free Software - Foundation, Inc., 59 Temple Place - Suite 330, - Boston, MA 02111-1307, USA. */ - -#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 "scm-lang.h" -#include "demangle.h" -#include "doublest.h" -#include "gdb_assert.h" - -/* Prototypes for exported functions. */ - -void _initialize_values (void); - -/* Prototypes for local functions. */ - -static struct value *value_headof (struct value *, struct type *, struct type *); - -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 *) xmalloc (sizeof (struct value) + TYPE_LENGTH (atype)); - VALUE_NEXT (val) = all_values; - all_values = val; - VALUE_TYPE (val) = type; - VALUE_ENCLOSING_TYPE (val) = type; - VALUE_LVAL (val) = not_lval; - VALUE_ADDRESS (val) = 0; - VALUE_FRAME (val) = 0; - VALUE_OFFSET (val) = 0; - VALUE_BITPOS (val) = 0; - VALUE_BITSIZE (val) = 0; - VALUE_REGNO (val) = -1; - VALUE_LAZY (val) = 0; - VALUE_OPTIMIZED_OUT (val) = 0; - VALUE_BFD_SECTION (val) = NULL; - VALUE_EMBEDDED_OFFSET (val) = 0; - VALUE_POINTED_TO_OFFSET (val) = 0; - val->modifiable = 1; - return val; -} - -/* Allocate a value that has the correct length - for COUNT repetitions 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)); -} - -/* 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 = VALUE_NEXT (val); - 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 = VALUE_NEXT (val); - 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 = VALUE_NEXT (next)) - if (VALUE_NEXT (next) == mark) - { - all_values = VALUE_NEXT (next); - VALUE_NEXT (next) = 0; - 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) -{ - register struct type *encl_type = VALUE_ENCLOSING_TYPE (arg); - struct value *val = allocate_value (encl_type); - VALUE_TYPE (val) = VALUE_TYPE (arg); - VALUE_LVAL (val) = VALUE_LVAL (arg); - VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); - VALUE_OFFSET (val) = VALUE_OFFSET (arg); - VALUE_BITPOS (val) = VALUE_BITPOS (arg); - VALUE_BITSIZE (val) = VALUE_BITSIZE (arg); - VALUE_FRAME (val) = VALUE_FRAME (arg); - VALUE_REGNO (val) = VALUE_REGNO (arg); - VALUE_LAZY (val) = VALUE_LAZY (arg); - VALUE_OPTIMIZED_OUT (val) = VALUE_OPTIMIZED_OUT (arg); - VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (arg); - VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (arg); - VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (arg); - 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; - register int i; - register 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 $%d.", absnum); - - absnum--; - - /* Now absnum is always absolute and origin zero. */ - - chunk = value_history_chain; - for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; - i > 0; i--) - chunk = chunk->next; - - return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); -} - -/* Clear the value history entirely. - Must be done when new symbol tables are loaded, - because the type pointers become invalid. */ - -void -clear_value_history (void) -{ - struct value_history_chunk *next; - register int i; - struct value *val; - - while (value_history_chain) - { - for (i = 0; i < VALUE_HISTORY_CHUNK; i++) - if ((val = value_history_chain->values[i]) != NULL) - xfree (val); - next = value_history_chain->next; - xfree (value_history_chain); - value_history_chain = next; - } - value_history_count = 0; -} - -static void -show_values (char *num_exp, int from_tty) -{ - register int i; - struct value *val; - static int num = 1; - - if (num_exp) - { - /* "info history +" should print from the stored position. - "info history <exp>" should print around value number <exp>. */ - if (num_exp[0] != '+' || num_exp[1] != '\0') - num = parse_and_eval_long (num_exp) - 5; - } - else - { - /* "info history" means print the last 10 values. */ - num = value_history_count - 9; - } - - if (num <= 0) - num = 1; - - for (i = num; i < num + 10 && i <= value_history_count; i++) - { - val = access_value_history (i); - printf_filtered ("$%d = ", i); - value_print (val, gdb_stdout, 0, Val_pretty_default); - printf_filtered ("\n"); - } - - /* The next "info history +" should start after what we just printed. */ - num += 10; - - /* Hitting just return after this command should do the same thing as - "info history +". If num_exp is null, this is unnecessary, since - "info history +" is not useful after "info history". */ - 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; - -/* 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) -{ - register struct internalvar *var; - - for (var = internalvars; var; var = var->next) - if (STREQ (var->name, name)) - return var; - - var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); - var->name = concat (name, NULL); - var->value = allocate_value (builtin_type_void); - release_value (var->value); - var->next = internalvars; - internalvars = var; - return var; -} - -struct value * -value_of_internalvar (struct internalvar *var) -{ - struct value *val; - -#ifdef IS_TRAPPED_INTERNALVAR - if (IS_TRAPPED_INTERNALVAR (var->name)) - return VALUE_OF_TRAPPED_INTERNALVAR (var); -#endif - - val = value_copy (var->value); - if (VALUE_LAZY (val)) - value_fetch_lazy (val); - VALUE_LVAL (val) = lval_internalvar; - VALUE_INTERNALVAR (val) = var; - return val; -} - -void -set_internalvar_component (struct internalvar *var, int offset, int bitpos, - int bitsize, struct value *newval) -{ - register char *addr = VALUE_CONTENTS (var->value) + offset; - -#ifdef IS_TRAPPED_INTERNALVAR - if (IS_TRAPPED_INTERNALVAR (var->name)) - SET_TRAPPED_INTERNALVAR (var, newval, bitpos, bitsize, offset); -#endif - - 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; - -#ifdef IS_TRAPPED_INTERNALVAR - if (IS_TRAPPED_INTERNALVAR (var->name)) - SET_TRAPPED_INTERNALVAR (var, val, 0, 0, 0); -#endif - - 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; - release_value (newval); - /* End code which must not call error(). */ -} - -char * -internalvar_name (struct internalvar *var) -{ - return var->name; -} - -/* Free all internalvars. Done when new symtabs are loaded, - because that makes the values invalid. */ - -void -clear_internalvars (void) -{ - register struct internalvar *var; - - while (internalvars) - { - var = internalvars; - internalvars = var->next; - xfree (var->name); - xfree (var->value); - xfree (var); - } -} - -static void -show_convenience (char *ignore, int from_tty) -{ - register struct internalvar *var; - int varseen = 0; - - for (var = internalvars; var; var = var->next) - { -#ifdef IS_TRAPPED_INTERNALVAR - if (IS_TRAPPED_INTERNALVAR (var->name)) - continue; -#endif - if (!varseen) - { - varseen = 1; - } - printf_filtered ("$%s = ", var->name); - value_print (var->value, 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. */ - 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 - /* 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 ADDR_BITS_REMOVE (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); - - 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 - && INTEGER_TO_ADDRESS_P ()) - return INTEGER_TO_ADDRESS (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, char *valaddr) -{ - register enum type_code code = TYPE_CODE (type); - register int len = TYPE_LENGTH (type); - register int nosign = TYPE_UNSIGNED (type); - - if (current_language->la_language == language_scm - && is_scmvalue_type (type)) - return scm_unpack (type, valaddr, TYPE_CODE_INT); - - switch (code) - { - case TYPE_CODE_TYPEDEF: - return unpack_long (check_typedef (type), valaddr); - case TYPE_CODE_ENUM: - case TYPE_CODE_BOOL: - case TYPE_CODE_INT: - case TYPE_CODE_CHAR: - case TYPE_CODE_RANGE: - 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_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); - - case TYPE_CODE_MEMBER: - error ("not implemented: member types in unpack_long"); - - 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, char *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 TARGET_FLOAT_FORMAT and TARGET_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 floatformat_is_invalid() function. */ - return extract_typed_floating (valaddr, type); - } - 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, char *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. */ - -struct value * -value_static_field (struct type *type, int fieldno) -{ - CORE_ADDR addr; - asection *sect; - if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno)) - { - addr = TYPE_FIELD_STATIC_PHYSADDR (type, fieldno); - sect = NULL; - } - else - { - char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); - struct symbol *sym = lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL); - 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 - { - addr = SYMBOL_VALUE_ADDRESS (msym); - sect = SYMBOL_BFD_SECTION (msym); - } - } - else - { - /* Anything static that isn't a constant, has an address */ - if (SYMBOL_CLASS (sym) != LOC_CONST) - { - addr = SYMBOL_VALUE_ADDRESS (sym); - sect = SYMBOL_BFD_SECTION (sym); - } - /* However, static const's do not, the value is already known. */ - else - { - return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), SYMBOL_VALUE (sym)); - } - } - SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), addr); - } - return value_at (TYPE_FIELD_TYPE (type, fieldno), addr, sect); -} - -/* 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))) - { - VALUE_ENCLOSING_TYPE (val) = 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)); - - /* 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, - register int fieldno, register struct type *arg_type) -{ - struct value *v; - register 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)); - VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; - VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (arg_type, fieldno); - VALUE_OFFSET (v) = 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)); - VALUE_TYPE (v) = type; - if (VALUE_LAZY (arg1)) - VALUE_LAZY (v) = 1; - else - memcpy (VALUE_CONTENTS_ALL_RAW (v), VALUE_CONTENTS_ALL_RAW (arg1), - TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg1))); - VALUE_OFFSET (v) = VALUE_OFFSET (arg1); - VALUE_EMBEDDED_OFFSET (v) - = 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_LAZY (arg1)) - VALUE_LAZY (v) = 1; - else - memcpy (VALUE_CONTENTS_RAW (v), - VALUE_CONTENTS_RAW (arg1) + offset, - TYPE_LENGTH (type)); - VALUE_OFFSET (v) = 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; - VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); - VALUE_REGNO (v) = VALUE_REGNO (arg1); -/* VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset - + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */ - 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, register 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; - register 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_NAMESPACE, 0, NULL); - 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 - { - VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym); - } - - 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; -} - -/* ARG is a pointer to an object we know to be at least - a DTYPE. BTYPE is the most derived basetype that has - already been searched (and need not be searched again). - After looking at the vtables between BTYPE and DTYPE, - return the most derived type we find. The caller must - be satisfied when the return value == DTYPE. - - FIXME-tiemann: should work with dossier entries as well. - NOTICE - djb: I see no good reason at all to keep this function now that - we have RTTI support. It's used in literally one place, and it's - hard to keep this function up to date when it's purpose is served - by value_rtti_type efficiently. - Consider it gone for 5.1. */ - -static struct value * -value_headof (struct value *in_arg, struct type *btype, struct type *dtype) -{ - /* First collect the vtables we must look at for this object. */ - struct value *arg; - struct value *vtbl; - struct symbol *sym; - char *demangled_name; - struct minimal_symbol *msymbol; - - btype = TYPE_VPTR_BASETYPE (dtype); - CHECK_TYPEDEF (btype); - arg = in_arg; - if (btype != dtype) - arg = value_cast (lookup_pointer_type (btype), arg); - if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_REF) - { - /* - * Copy the value, but change the type from (T&) to (T*). - * We keep the same location information, which is efficient, - * and allows &(&X) to get the location containing the reference. - */ - arg = value_copy (arg); - VALUE_TYPE (arg) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg))); - } - if (VALUE_ADDRESS(value_field (value_ind(arg), TYPE_VPTR_FIELDNO (btype)))==0) - return arg; - - vtbl = value_ind (value_field (value_ind (arg), TYPE_VPTR_FIELDNO (btype))); - /* Turn vtable into typeinfo function */ - VALUE_OFFSET(vtbl)+=4; - - msymbol = lookup_minimal_symbol_by_pc ( value_as_address(value_ind(vtbl)) ); - if (msymbol == NULL - || (demangled_name = SYMBOL_NAME (msymbol)) == NULL) - { - /* If we expected to find a vtable, but did not, let the user - know that we aren't happy, but don't throw an error. - FIXME: there has to be a better way to do this. */ - struct type *error_type = (struct type *) xmalloc (sizeof (struct type)); - memcpy (error_type, VALUE_TYPE (in_arg), sizeof (struct type)); - TYPE_NAME (error_type) = savestring ("suspicious *", sizeof ("suspicious *")); - VALUE_TYPE (in_arg) = error_type; - return in_arg; - } - demangled_name = cplus_demangle(demangled_name,DMGL_ANSI); - *(strchr (demangled_name, ' ')) = '\0'; - - sym = lookup_symbol (demangled_name, 0, VAR_NAMESPACE, 0, 0); - if (sym == NULL) - error ("could not find type declaration for `%s'", demangled_name); - - arg = in_arg; - VALUE_TYPE (arg) = lookup_pointer_type (SYMBOL_TYPE (sym)); - return arg; -} - -/* ARG is a pointer object of type TYPE. If TYPE has virtual - function tables, probe ARG's tables (including the vtables - of its baseclasses) to figure out the most derived type that ARG - could actually be a pointer to. */ - -struct value * -value_from_vtable_info (struct value *arg, struct type *type) -{ - /* Take care of preliminaries. */ - if (TYPE_VPTR_FIELDNO (type) < 0) - fill_in_vptr_fieldno (type); - if (TYPE_VPTR_FIELDNO (type) < 0) - return 0; - - return value_headof (arg, 0, type); -} - -/* 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, char *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 (BITS_BIG_ENDIAN) - 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. */ - -void -modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize) -{ - LONGEST oword; - - /* If a negative fieldval fits in the field in question, chop - off the sign extension bits. */ - if (bitsize < (8 * (int) sizeof (fieldval)) - && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0) - fieldval = fieldval & ((1 << bitsize) - 1); - - /* Warn if value is too big to fit in the field in question. */ - if (bitsize < (8 * (int) sizeof (fieldval)) - && 0 != (fieldval & ~((1 << bitsize) - 1))) - { - /* 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 = fieldval & ((1 << bitsize) - 1); - } - - oword = extract_signed_integer (addr, sizeof oword); - - /* Shifting for bit field depends on endianness of the target machine. */ - if (BITS_BIG_ENDIAN) - bitpos = sizeof (oword) * 8 - bitpos - bitsize; - - /* Mask out old value, while avoiding shifts >= size of oword */ - if (bitsize < 8 * (int) sizeof (oword)) - oword &= ~(((((ULONGEST) 1) << bitsize) - 1) << bitpos); - else - oword &= ~((~(ULONGEST) 0) << bitpos); - oword |= fieldval << bitpos; - - store_signed_integer (addr, sizeof oword, oword); -} - -/* Convert C numbers into newly allocated values */ - -struct value * -value_from_longest (struct type *type, register LONGEST num) -{ - struct value *val = allocate_value (type); - register enum type_code code; - register int len; -retry: - code = TYPE_CODE (type); - len = TYPE_LENGTH (type); - - switch (code) - { - case TYPE_CODE_TYPEDEF: - type = check_typedef (type); - goto retry; - case TYPE_CODE_INT: - case TYPE_CODE_CHAR: - case TYPE_CODE_ENUM: - case TYPE_CODE_BOOL: - case TYPE_CODE_RANGE: - store_signed_integer (VALUE_CONTENTS_RAW (val), len, num); - break; - - case TYPE_CODE_REF: - case TYPE_CODE_PTR: - store_typed_address (VALUE_CONTENTS_RAW (val), type, (CORE_ADDR) num); - break; - - default: - error ("Unexpected type (%d) encountered for integer constant.", code); - } - 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 *rangetype = - create_range_type ((struct type *) NULL, - builtin_type_int, - lowbound, len + lowbound - 1); - struct type *stringtype = - create_array_type ((struct type *) NULL, - *current_language->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); - register enum type_code code = TYPE_CODE (base_type); - register 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; -} - -/* Deal with the value that is "about to be returned". */ - -/* Return the value that a function returning now - would be returning to its caller, assuming its type is VALTYPE. - RETBUF is where we look for what ought to be the contents - of the registers (in raw form). This is because it is often - desirable to restore old values to those registers - after saving the contents of interest, and then call - this function using the saved values. - struct_return is non-zero when the function in question is - using the structure return conventions on the machine in question; - 0 when it is using the value returning conventions (this often - means returning pointer to where structure is vs. returning value). */ - -/* ARGSUSED */ -struct value * -value_being_returned (struct type *valtype, char *retbuf, int struct_return) -{ - struct value *val; - CORE_ADDR addr; - - /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */ - if (EXTRACT_STRUCT_VALUE_ADDRESS_P ()) - if (struct_return) - { - addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf); - if (!addr) - error ("Function return value unknown."); - return value_at (valtype, addr, NULL); - } - - val = allocate_value (valtype); - CHECK_TYPEDEF (valtype); - EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val)); - - return val; -} - -/* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of - EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc - and TYPE is the type (which is known to be struct, union or array). - - On most machines, the struct convention is used unless we are - using gcc and the type is of a special size. */ -/* As of about 31 Mar 93, GCC was changed to be compatible with the - native compiler. GCC 2.3.3 was the last release that did it the - old way. Since gcc2_compiled was not changed, we have no - way to correctly win in all cases, so we just do the right thing - for gcc1 and for gcc2 after this change. Thus it loses for gcc - 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled - would cause more chaos than dealing with some struct returns being - handled wrong. */ - -int -generic_use_struct_convention (int gcc_p, struct type *value_type) -{ - return !((gcc_p == 1) - && (TYPE_LENGTH (value_type) == 1 - || TYPE_LENGTH (value_type) == 2 - || TYPE_LENGTH (value_type) == 4 - || TYPE_LENGTH (value_type) == 8)); -} - -/* Return true if the function specified is using the structure returning - convention on this machine to return arguments, or 0 if it is using - the value returning convention. FUNCTION is the value representing - the function, FUNCADDR is the address of the function, and VALUE_TYPE - is the type returned by the function. GCC_P is nonzero if compiled - with GCC. */ - -/* ARGSUSED */ -int -using_struct_return (struct value *function, CORE_ADDR funcaddr, - struct type *value_type, int gcc_p) -{ - register enum type_code code = TYPE_CODE (value_type); - - if (code == TYPE_CODE_ERROR) - error ("Function return type unknown."); - - if (code == TYPE_CODE_STRUCT - || code == TYPE_CODE_UNION - || code == TYPE_CODE_ARRAY - || RETURN_VALUE_ON_STACK (value_type)) - return USE_STRUCT_CONVENTION (gcc_p, value_type); - - return 0; -} - -/* Store VAL so it will be returned if a function returns now. - Does not verify that VAL's type matches what the current - function wants to return. */ - -void -set_return_value (struct value *val) -{ - struct type *type = check_typedef (VALUE_TYPE (val)); - register enum type_code code = TYPE_CODE (type); - - if (code == TYPE_CODE_ERROR) - error ("Function return type unknown."); - - if (code == TYPE_CODE_STRUCT - || code == TYPE_CODE_UNION) /* FIXME, implement struct return. */ - error ("GDB does not support specifying a struct or union return value."); - - STORE_RETURN_VALUE (type, VALUE_CONTENTS (val)); -} - -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); -} |