/* Definitions for values of C expressions, for GDB.
- Copyright (C) 1986-2021 Free Software Foundation, Inc.
+ Copyright (C) 1986-2023 Free Software Foundation, Inc.
This file is part of GDB.
extern bool overload_resolution;
-/* The structure which defines the type of a value. It should never
- be possible for a program lval value to survive over a call to the
- inferior (i.e. to be put into the history list or an internal
- variable). */
+/* Defines an [OFFSET, OFFSET + LENGTH) range. */
-struct value;
+struct range
+{
+ /* Lowest offset in the range. */
+ LONGEST offset;
-/* Increase VAL's reference count. */
+ /* Length of the range. */
+ ULONGEST length;
-extern void value_incref (struct value *val);
+ /* Returns true if THIS is strictly less than OTHER, useful for
+ searching. We keep ranges sorted by offset and coalesce
+ overlapping and contiguous ranges, so this just compares the
+ starting offset. */
-/* Decrease VAL's reference count. When the reference count drops to
- 0, VAL will be freed. */
+ bool operator< (const range &other) const
+ {
+ return offset < other.offset;
+ }
-extern void value_decref (struct value *val);
+ /* Returns true if THIS is equal to OTHER. */
+ bool operator== (const range &other) const
+ {
+ return offset == other.offset && length == other.length;
+ }
+};
/* A policy class to interface gdb::ref_ptr with struct value. */
struct value_ref_policy
{
- static void incref (struct value *ptr)
- {
- value_incref (ptr);
- }
-
- static void decref (struct value *ptr)
- {
- value_decref (ptr);
- }
+ static void incref (struct value *ptr);
+ static void decref (struct value *ptr);
};
/* A gdb:;ref_ptr pointer to a struct value. */
typedef gdb::ref_ptr<struct value, value_ref_policy> value_ref_ptr;
-/* Values are stored in a chain, so that they can be deleted easily
- over calls to the inferior. Values assigned to internal variables,
- put into the value history or exposed to Python are taken off this
- list. */
+/* Note that the fields in this structure are arranged to save a bit
+ of memory. */
+
+struct value
+{
+private:
+
+ /* Values can only be created via "static constructors". */
+ explicit value (struct type *type_)
+ : m_modifiable (true),
+ m_lazy (true),
+ m_initialized (true),
+ m_stack (false),
+ m_is_zero (false),
+ m_in_history (false),
+ m_type (type_),
+ m_enclosing_type (type_)
+ {
+ }
+
+ /* Values can only be destroyed via the reference-counting
+ mechanism. */
+ ~value ();
+
+ DISABLE_COPY_AND_ASSIGN (value);
+
+public:
+
+ /* Allocate a lazy value for type TYPE. Its actual content is
+ "lazily" allocated too: the content field of the return value is
+ NULL; it will be allocated when it is fetched from the target. */
+ static struct value *allocate_lazy (struct type *type);
+
+ /* Allocate a value and its contents for type TYPE. */
+ static struct value *allocate (struct type *type);
+
+ /* Create a computed lvalue, with type TYPE, function pointers
+ FUNCS, and closure CLOSURE. */
+ static struct value *allocate_computed (struct type *type,
+ const struct lval_funcs *funcs,
+ void *closure);
+
+ /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
+ static struct value *allocate_optimized_out (struct type *type);
+
+ /* Create a value of type TYPE that is zero, and return it. */
+ static struct value *zero (struct type *type, enum lval_type lv);
+
+ /* Return a copy of the value. It contains the same contents, for
+ the same memory address, but it's a different block of
+ storage. */
+ struct value *copy () const;
+
+ /* Type of the value. */
+ struct type *type () const
+ { return m_type; }
+
+ /* This is being used to change the type of an existing value, that
+ code should instead be creating a new value with the changed type
+ (but possibly shared content). */
+ void deprecated_set_type (struct type *type)
+ { m_type = type; }
+
+ /* Return the gdbarch associated with the value. */
+ struct gdbarch *arch () const;
+
+ /* Only used for bitfields; number of bits contained in them. */
+ LONGEST bitsize () const
+ { return m_bitsize; }
+
+ void set_bitsize (LONGEST bit)
+ { m_bitsize = bit; }
+
+ /* Only used for bitfields; position of start of field. For
+ little-endian targets, it is the position of the LSB. For
+ big-endian targets, it is the position of the MSB. */
+ LONGEST bitpos () const
+ { return m_bitpos; }
+
+ void set_bitpos (LONGEST bit)
+ { m_bitpos = bit; }
+
+ /* Only used for bitfields; the containing value. This allows a
+ single read from the target when displaying multiple
+ bitfields. */
+ value *parent () const
+ { return m_parent.get (); }
+
+ void set_parent (struct value *parent)
+ { m_parent = value_ref_ptr::new_reference (parent); }
+
+ /* 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. */
+ LONGEST offset () const
+ { return m_offset; }
+
+ void set_offset (LONGEST offset)
+ { m_offset = offset; }
+
+ /* The comment from "struct value" reads: ``Is it modifiable? Only
+ relevant if lval != not_lval.''. Shouldn't the value instead be
+ not_lval and be done with it? */
+ bool deprecated_modifiable () const
+ { return m_modifiable; }
+
+ /* Set or clear the modifiable flag. */
+ void set_modifiable (bool val)
+ { m_modifiable = val; }
+
+ LONGEST pointed_to_offset () const
+ { return m_pointed_to_offset; }
+
+ void set_pointed_to_offset (LONGEST val)
+ { m_pointed_to_offset = val; }
+
+ LONGEST embedded_offset () const
+ { return m_embedded_offset; }
+
+ void set_embedded_offset (LONGEST val)
+ { m_embedded_offset = val; }
+
+ /* If false, contents of this value are in the contents field. If
+ true, 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! */
+
+ bool lazy () const
+ { return m_lazy; }
+
+ void set_lazy (bool val)
+ { m_lazy = val; }
+
+ /* 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 contents()
+ method 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 () const
+ { return m_enclosing_type; }
+
+ void set_enclosing_type (struct type *new_type);
+
+ bool stack () const
+ { return m_stack; }
+
+ void set_stack (bool val)
+ { m_stack = val; }
+
+ /* If this value is lval_computed, return its lval_funcs
+ structure. */
+ const struct lval_funcs *computed_funcs () const;
+
+ /* If this value is lval_computed, return its closure. The meaning
+ of the returned value depends on the functions this value
+ uses. */
+ void *computed_closure () const;
+
+ enum lval_type lval () const
+ { return m_lval; }
+
+ /* Set the 'lval' of this value. */
+ void set_lval (lval_type val)
+ { m_lval = val; }
+
+ /* Set or return field indicating whether a variable is initialized or
+ not, based on debugging information supplied by the compiler.
+ true = initialized; false = uninitialized. */
+ bool initialized () const
+ { return m_initialized; }
+
+ void set_initialized (bool value)
+ { m_initialized = value; }
+
+ /* If lval == lval_memory, return the address in the inferior. If
+ lval == lval_register, return the byte offset into the registers
+ structure. Otherwise, return 0. The returned address
+ includes the offset, if any. */
+ CORE_ADDR address () const;
+
+ /* Like address, except the result does not include value's
+ offset. */
+ CORE_ADDR raw_address () const;
+
+ /* Set the address of a value. */
+ void set_address (CORE_ADDR);
+
+ struct internalvar **deprecated_internalvar_hack ()
+ { return &m_location.internalvar; }
+
+ struct frame_id *deprecated_next_frame_id_hack ();
+
+ int *deprecated_regnum_hack ();
+
+ /* contents() and contents_raw() both return the address of the gdb
+ buffer used to hold a copy of the contents of the lval.
+ contents() is used when the contents of the buffer are needed --
+ it uses fetch_lazy() to load the buffer from the process being
+ debugged if it hasn't already been loaded (contents_writeable()
+ is used when a writeable but fetched buffer is required)..
+ contents_raw() is used when data is being stored into the buffer,
+ or when it is certain that the contents of the buffer are valid.
+
+ Note: The contents pointer is adjusted by the offset required to
+ get to the real subobject, if the value happens to represent
+ something embedded in a larger run-time object. */
+ gdb::array_view<gdb_byte> contents_raw ();
+
+ /* 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. */
+ gdb::array_view<const gdb_byte> contents ();
+
+ /* The ALL variants of the above two methods do not adjust the
+ returned pointer by the embedded_offset value. */
+ gdb::array_view<const gdb_byte> contents_all ();
+ gdb::array_view<gdb_byte> contents_all_raw ();
+
+ gdb::array_view<gdb_byte> contents_writeable ();
+
+ /* Like contents_all, but does not require that the returned bits be
+ valid. This should only be used in situations where you plan to
+ check the validity manually. */
+ gdb::array_view<const gdb_byte> contents_for_printing ();
-struct value *value_next (const struct value *);
+ /* Like contents_for_printing, but accepts a constant value pointer.
+ Unlike contents_for_printing however, the pointed value must
+ _not_ be lazy. */
+ gdb::array_view<const gdb_byte> contents_for_printing () const;
-/* Type of the value. */
+ /* Load the actual content of a lazy value. Fetch the data from the
+ user's process and clear the lazy flag to indicate that the data in
+ the buffer is valid.
-extern struct type *value_type (const struct value *);
+ If the value is zero-length, we avoid calling read_memory, which
+ would abort. We mark the value as fetched anyway -- all 0 bytes of
+ it. */
+ void fetch_lazy ();
-/* Return the gdbarch associated with the value. */
+ /* Compare LENGTH bytes of this value's contents starting at OFFSET1
+ with LENGTH bytes of VAL2's contents starting at OFFSET2.
-extern struct gdbarch *get_value_arch (const struct value *value);
+ Note that "contents" refers to the whole value's contents
+ (value_contents_all), without any embedded offset adjustment. For
+ example, to compare a complete object value with itself, including
+ its enclosing type chunk, you'd do:
-/* This is being used to change the type of an existing value, that
- code should instead be creating a new value with the changed type
- (but possibly shared content). */
+ int len = check_typedef (val->enclosing_type ())->length ();
+ val->contents_eq (0, val, 0, len);
-extern void deprecated_set_value_type (struct value *value,
- struct type *type);
+ Returns true iff the set of available/valid contents match.
-/* Only used for bitfields; number of bits contained in them. */
+ Optimized-out contents are equal to optimized-out contents, and are
+ not equal to non-optimized-out contents.
-extern LONGEST value_bitsize (const struct value *);
-extern void set_value_bitsize (struct value *, LONGEST bit);
+ Unavailable contents are equal to unavailable contents, and are not
+ equal to non-unavailable contents.
-/* Only used for bitfields; position of start of field. For
- little-endian targets, it is the position of the LSB. For
- big-endian targets, it is the position of the MSB. */
+ For example, if 'x's represent an unavailable byte, and 'V' and 'Z'
+ represent different available/valid bytes, in a value with length
+ 16:
-extern LONGEST value_bitpos (const struct value *);
-extern void set_value_bitpos (struct value *, LONGEST bit);
+ offset: 0 4 8 12 16
+ contents: xxxxVVVVxxxxVVZZ
+
+ then:
+
+ val->contents_eq(0, val, 8, 6) => true
+ val->contents_eq(0, val, 4, 4) => false
+ val->contents_eq(0, val, 8, 8) => false
+ val->contents_eq(4, val, 12, 2) => true
+ val->contents_eq(4, val, 12, 4) => true
+ val->contents_eq(3, val, 4, 4) => true
+
+ If 'x's represent an unavailable byte, 'o' represents an optimized
+ out byte, in a value with length 8:
+
+ offset: 0 4 8
+ contents: xxxxoooo
+
+ then:
+
+ val->contents_eq(0, val, 2, 2) => true
+ val->contents_eq(4, val, 6, 2) => true
+ val->contents_eq(0, val, 4, 4) => true
+
+ We only know whether a value chunk is unavailable or optimized out
+ if we've tried to read it. As this routine is used by printing
+ routines, which may be printing values in the value history, long
+ after the inferior is gone, it works with const values. Therefore,
+ this routine must not be called with lazy values. */
-/* Only used for bitfields; the containing value. This allows a
- single read from the target when displaying multiple
- bitfields. */
+ bool contents_eq (LONGEST offset1, const struct value *val2, LONGEST offset2,
+ LONGEST length) const;
-struct value *value_parent (const struct value *);
-extern void set_value_parent (struct value *value, struct value *parent);
+ /* An overload of contents_eq that compares the entirety of both
+ values. */
+ bool contents_eq (const struct value *val2) const;
-/* 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. */
+ /* Given a value, determine whether the bits starting at OFFSET and
+ extending for LENGTH bits are a synthetic pointer. */
-extern LONGEST value_offset (const struct value *);
-extern void set_value_offset (struct value *, LONGEST offset);
+ bool bits_synthetic_pointer (LONGEST offset, LONGEST length) const;
-/* The comment from "struct value" reads: ``Is it modifiable? Only
- relevant if lval != not_lval.''. Shouldn't the value instead be
- not_lval and be done with it? */
+ /* Increase this value's reference count. */
+ void incref ()
+ { ++m_reference_count; }
-extern int deprecated_value_modifiable (const struct value *value);
+ /* Decrease this value's reference count. When the reference count
+ drops to 0, it will be freed. */
+ void decref ();
-/* 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.
+ /* Given a value, determine whether the contents bytes starting at
+ OFFSET and extending for LENGTH bytes are available. This returns
+ true if all bytes in the given range are available, false if any
+ byte is unavailable. */
+ bool bytes_available (LONGEST offset, ULONGEST length) const;
- 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:
+ /* Given a value, determine whether the contents bits starting at
+ OFFSET and extending for LENGTH bits are available. This returns
+ true if all bits in the given range are available, false if any
+ bit is unavailable. */
+ bool bits_available (LONGEST offset, ULONGEST length) const;
- - When printing the value, the user would probably rather see the
+ /* Like bytes_available, but return false if any byte in the
+ whole object is unavailable. */
+ bool entirely_available ();
+
+ /* Like entirely_available, but return false if any byte in the
+ whole object is available. */
+ bool entirely_unavailable ()
+ { return entirely_covered_by_range_vector (m_unavailable); }
+
+ /* Mark this value's content bytes starting at OFFSET and extending
+ for LENGTH bytes as unavailable. */
+ void mark_bytes_unavailable (LONGEST offset, ULONGEST length);
+
+ /* Mark this value's content bits starting at OFFSET and extending
+ for LENGTH bits as unavailable. */
+ void mark_bits_unavailable (LONGEST offset, ULONGEST length);
+
+ /* If true, this is the value of a variable which does not actually
+ exist in the program, at least partially. If the value is lazy,
+ this may fetch it now. */
+ bool optimized_out ();
+
+ /* Given a value, return true if any of the contents bits starting at
+ OFFSET and extending for LENGTH bits is optimized out, false
+ otherwise. */
+ bool bits_any_optimized_out (int bit_offset, int bit_length) const;
+
+ /* Like optimized_out, but return true iff the whole value is
+ optimized out. */
+ bool entirely_optimized_out ()
+ {
+ return entirely_covered_by_range_vector (m_optimized_out);
+ }
+
+ /* Mark this value's content bytes starting at OFFSET and extending
+ for LENGTH bytes as optimized out. */
+ void mark_bytes_optimized_out (int offset, int length);
+
+ /* Mark this value's content bits starting at OFFSET and extending
+ for LENGTH bits as optimized out. */
+ void mark_bits_optimized_out (LONGEST offset, LONGEST length);
+
+ /* Return a version of this that is non-lvalue. */
+ struct value *non_lval ();
+
+ /* Write contents of this value at ADDR and set its lval type to be
+ LVAL_MEMORY. */
+ void force_lval (CORE_ADDR);
+
+ /* Set this values's location as appropriate for a component of
+ WHOLE --- regardless of what kind of lvalue WHOLE is. */
+ void set_component_location (const struct value *whole);
+
+ /* Build a value wrapping and representing WORKER. The value takes
+ ownership of the xmethod_worker object. */
+ static struct value *from_xmethod (xmethod_worker_up &&worker);
+
+ /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
+ struct type *result_type_of_xmethod (gdb::array_view<value *> argv);
+
+ /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value
+ METHOD. */
+ struct value *call_xmethod (gdb::array_view<value *> argv);
+
+ /* Update this value before discarding OBJFILE. COPIED_TYPES is
+ used to prevent cycles / duplicates. */
+ void preserve (struct objfile *objfile, htab_t copied_types);
+
+ /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object
+ at VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and
+ store the contents in DEST_VAL, zero or sign extending if the
+ type of DEST_VAL is wider than BITSIZE. VALADDR points to the
+ contents of this value. If this value's contents required to
+ extract the bitfield from are unavailable/optimized out, DEST_VAL
+ is correspondingly marked unavailable/optimized out. */
+ void unpack_bitfield (struct value *dest_val,
+ LONGEST bitpos, LONGEST bitsize,
+ const gdb_byte *valaddr, LONGEST embedded_offset)
+ const;
+
+ /* Copy LENGTH bytes of this value's (all) contents
+ (value_contents_all) starting at SRC_OFFSET byte, into DST
+ value's (all) contents, starting at DST_OFFSET. If unavailable
+ contents are being copied from this value, the corresponding DST
+ contents are marked unavailable accordingly. DST must not be
+ lazy. If this value is lazy, it will be fetched now.
+
+ It is assumed the contents of DST in the [DST_OFFSET,
+ DST_OFFSET+LENGTH) range are wholly available. */
+ void contents_copy (struct value *dst, LONGEST dst_offset,
+ LONGEST src_offset, LONGEST length);
+
+ /* Given a value (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 *primitive_field (LONGEST offset, int fieldno,
+ struct type *arg_type);
+
+ /* Create a new value by extracting it from this value. TYPE is the
+ type of the new value. BIT_OFFSET and BIT_LENGTH describe the
+ offset and field width of the value to extract from this value --
+ BIT_LENGTH may differ from TYPE's length in the case where this
+ value's type is packed.
+
+ When the value does come from a non-byte-aligned offset or field
+ width, it will be marked non_lval. */
+ struct value *from_component_bitsize (struct type *type,
+ LONGEST bit_offset,
+ LONGEST bit_length);
+
+ /* Record this value on the value history, and return its location
+ in the history. The value is removed from the value chain. */
+ int record_latest ();
+
+private:
+
+ /* Type of value; either not an lval, or one of the various
+ different possible kinds of lval. */
+ enum lval_type m_lval = not_lval;
+
+ /* Is it modifiable? Only relevant if lval != not_lval. */
+ bool m_modifiable : 1;
+
+ /* If false, contents of this value are in the contents field. If
+ true, 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! */
+ bool m_lazy : 1;
+
+ /* If value is a variable, is it initialized or not. */
+ bool m_initialized : 1;
+
+ /* If value is from the stack. If this is set, read_stack will be
+ used instead of read_memory to enable extra caching. */
+ bool m_stack : 1;
+
+ /* True if this is a zero value, created by 'value::zero'; false
+ otherwise. */
+ bool m_is_zero : 1;
+
+ /* True if this a value recorded in value history; false otherwise. */
+ bool m_in_history : 1;
+
+ /* Location of value (if lval). */
+ union
+ {
+ /* If lval == lval_memory, this is the address in the inferior */
+ CORE_ADDR address;
+
+ /*If lval == lval_register, the value is from a register. */
+ struct
+ {
+ /* Register number. */
+ int regnum;
+ /* Frame ID of "next" frame to which a register value is relative.
+ If the register value is found relative to frame F, then the
+ frame id of F->next will be stored in next_frame_id. */
+ struct frame_id next_frame_id;
+ } reg;
+
+ /* Pointer to internal variable. */
+ struct internalvar *internalvar;
+
+ /* Pointer to xmethod worker. */
+ struct xmethod_worker *xm_worker;
+
+ /* If lval == lval_computed, this is a set of function pointers
+ to use to access and describe the value, and a closure pointer
+ for them to use. */
+ struct
+ {
+ /* Functions to call. */
+ const struct lval_funcs *funcs;
+
+ /* Closure for those functions to use. */
+ void *closure;
+ } computed;
+ } m_location {};
+
+ /* Describes offset of a value within lval of a structure in target
+ addressable memory units. Note also the member embedded_offset
+ below. */
+ LONGEST m_offset = 0;
+
+ /* Only used for bitfields; number of bits contained in them. */
+ LONGEST m_bitsize = 0;
+
+ /* Only used for bitfields; position of start of field. For
+ little-endian targets, it is the position of the LSB. For
+ big-endian targets, it is the position of the MSB. */
+ LONGEST m_bitpos = 0;
+
+ /* The number of references to this value. When a value is created,
+ the value chain holds a reference, so REFERENCE_COUNT is 1. If
+ release_value is called, this value is removed from the chain but
+ the caller of release_value now has a reference to this value.
+ The caller must arrange for a call to value_free later. */
+ int m_reference_count = 1;
+
+ /* Only used for bitfields; the containing value. This allows a
+ single read from the target when displaying multiple
+ bitfields. */
+ value_ref_ptr m_parent;
+
+ /* Type of the value. */
+ struct type *m_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'
+ - 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. */
-
-extern struct type *value_enclosing_type (const struct value *);
-extern void set_value_enclosing_type (struct value *val,
- struct type *new_type);
+ 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 target addressable memory
+ units. The contents() method 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 target addressable memory units 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 *m_enclosing_type;
+ LONGEST m_embedded_offset = 0;
+ LONGEST m_pointed_to_offset = 0;
+
+ /* Actual contents of the value. Target byte-order.
+
+ May be nullptr if the value is lazy or is entirely optimized out.
+ Guaranteed to be non-nullptr otherwise. */
+ gdb::unique_xmalloc_ptr<gdb_byte> m_contents;
+
+ /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
+ rather than available, since the common and default case is for a
+ value to be available. This is filled in at value read time.
+ The unavailable ranges are tracked in bits. Note that a contents
+ bit that has been optimized out doesn't really exist in the
+ program, so it can't be marked unavailable either. */
+ std::vector<range> m_unavailable;
+
+ /* Likewise, but for optimized out contents (a chunk of the value of
+ a variable that does not actually exist in the program). If LVAL
+ is lval_register, this is a register ($pc, $sp, etc., never a
+ program variable) that has not been saved in the frame. Not
+ saved registers and optimized-out program variables values are
+ treated pretty much the same, except not-saved registers have a
+ different string representation and related error strings. */
+ std::vector<range> m_optimized_out;
+
+ /* This is only non-zero for values of TYPE_CODE_ARRAY and if the size of
+ the array in inferior memory is greater than max_value_size. If these
+ conditions are met then, when the value is loaded from the inferior
+ GDB will only load a portion of the array into memory, and
+ limited_length will be set to indicate the length in octets that were
+ loaded from the inferior. */
+ ULONGEST m_limited_length = 0;
+
+ /* Allocate a value and its contents for type TYPE. If CHECK_SIZE
+ is true, then apply the usual max-value-size checks. */
+ static struct value *allocate (struct type *type, bool check_size);
+
+ /* Helper for fetch_lazy when the value is a bitfield. */
+ void fetch_lazy_bitfield ();
+
+ /* Helper for fetch_lazy when the value is in memory. */
+ void fetch_lazy_memory ();
+
+ /* Helper for fetch_lazy when the value is in a register. */
+ void fetch_lazy_register ();
+
+ /* Try to limit ourselves to only fetching the limited number of
+ elements. However, if this limited number of elements still
+ puts us over max_value_size, then we still refuse it and
+ return failure here, which will ultimately throw an error. */
+ bool set_limited_array_length ();
+
+ /* Allocate the contents of this value if it has not been allocated
+ yet. If CHECK_SIZE is true, then apply the usual max-value-size
+ checks. */
+ void allocate_contents (bool check_size);
+
+ /* Helper function for value_contents_eq. The only difference is that
+ this function is bit rather than byte based.
+
+ Compare LENGTH bits of this value's contents starting at OFFSET1
+ bits with LENGTH bits of VAL2's contents starting at OFFSET2
+ bits. Return true if the available bits match. */
+ bool contents_bits_eq (int offset1, const struct value *val2, int offset2,
+ int length) const;
+
+ void require_not_optimized_out () const;
+ void require_available () const;
+
+ /* Returns true if this value is entirely covered by RANGES. If the
+ value is lazy, it'll be read now. Note that RANGE is a pointer
+ to pointer because reading the value might change *RANGE. */
+ bool entirely_covered_by_range_vector (const std::vector<range> &ranges);
+
+ /* Copy the ranges metadata from this value that overlaps
+ [SRC_BIT_OFFSET, SRC_BIT_OFFSET+BIT_LENGTH) into DST,
+ adjusted. */
+ void ranges_copy_adjusted (struct value *dst, int dst_bit_offset,
+ int src_bit_offset, int bit_length) const;
+
+ /* Copy LENGTH target addressable memory units of this value's (all)
+ contents (value_contents_all) starting at SRC_OFFSET, into DST
+ value's (all) contents, starting at DST_OFFSET. If unavailable
+ contents are being copied from this, the corresponding DST
+ contents are marked unavailable accordingly. Neither DST nor
+ this value may be lazy values.
+
+ It is assumed the contents of DST in the [DST_OFFSET,
+ DST_OFFSET+LENGTH) range are wholly available. */
+ void contents_copy_raw (struct value *dst, LONGEST dst_offset,
+ LONGEST src_offset, LONGEST length);
+
+ /* A helper for value_from_component_bitsize that copies bits from
+ this value to DEST. */
+ void contents_copy_raw_bitwise (struct value *dst, LONGEST dst_bit_offset,
+ LONGEST src_bit_offset, LONGEST bit_length);
+};
+
+inline void
+value_ref_policy::incref (struct value *ptr)
+{
+ ptr->incref ();
+}
+
+inline void
+value_ref_policy::decref (struct value *ptr)
+{
+ ptr->decref ();
+}
/* Returns value_type or value_enclosing_type depending on
value_print_options.objectprint.
int resolve_simple_types,
int *real_type_found);
-extern LONGEST value_pointed_to_offset (const struct value *value);
-extern void set_value_pointed_to_offset (struct value *value, LONGEST val);
-extern LONGEST value_embedded_offset (const struct value *value);
-extern void set_value_embedded_offset (struct value *value, LONGEST val);
-
/* For lval_computed values, this structure holds functions used to
retrieve and set the value (or portions of the value).
TOVAL is not considered as an lvalue. */
void (*write) (struct value *toval, struct value *fromval);
+ /* Return true if any part of V is optimized out, false otherwise.
+ This will only be called for lazy values -- if the value has been
+ fetched, then the value's optimized-out bits are consulted
+ instead. */
+ bool (*is_optimized_out) (struct value *v);
+
/* If non-NULL, this is used to implement pointer indirection for
this value. This method may return NULL, in which case value_ind
will fall back to ordinary indirection. */
/* If non-NULL, this is used to determine whether the indicated bits
of VALUE are a synthetic pointer. */
- int (*check_synthetic_pointer) (const struct value *value,
- LONGEST offset, int length);
+ bool (*check_synthetic_pointer) (const struct value *value,
+ LONGEST offset, int length);
/* Return a duplicate of VALUE's closure, for use in a new value.
This may simply return the same closure, if VALUE's is
void (*free_closure) (struct value *v);
};
-/* Create a computed lvalue, with type TYPE, function pointers FUNCS,
- and closure CLOSURE. */
-
-extern struct value *allocate_computed_value (struct type *type,
- const struct lval_funcs *funcs,
- void *closure);
-
-extern struct value *allocate_optimized_out_value (struct type *type);
-
-/* If VALUE is lval_computed, return its lval_funcs structure. */
-
-extern const struct lval_funcs *value_computed_funcs (const struct value *);
-
-/* If VALUE is lval_computed, return its closure. The meaning of the
- returned value depends on the functions VALUE uses. */
-
-extern void *value_computed_closure (const struct value *value);
-
-/* 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! */
-
-extern int value_lazy (const struct value *);
-extern void set_value_lazy (struct value *value, int val);
-
-extern int value_stack (const struct value *);
-extern void set_value_stack (struct value *value, int val);
-
/* Throw an error complaining that the value has been optimized
out. */
extern void error_value_optimized_out (void);
-/* value_contents() and value_contents_raw() both return the address
- of the gdb buffer used to hold a copy of the contents of the lval.
- value_contents() is used when the contents of the buffer are needed
- -- it uses value_fetch_lazy() to load the buffer from the process
- being debugged if it hasn't already been loaded
- (value_contents_writeable() is used when a writeable but fetched
- buffer is required).. value_contents_raw() is used when data is
- being stored into the buffer, or when it is certain that the
- contents of the buffer are valid.
-
- Note: The contents pointer is adjusted by the offset required to
- get to the real subobject, if the value happens to represent
- something embedded in a larger run-time object. */
-
-extern gdb_byte *value_contents_raw (struct value *);
-
-/* 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. */
-
-extern const gdb_byte *value_contents (struct value *);
-extern gdb_byte *value_contents_writeable (struct value *);
-
-/* The ALL variants of the above two macros do not adjust the returned
- pointer by the embedded_offset value. */
-
-extern gdb_byte *value_contents_all_raw (struct value *);
-extern const gdb_byte *value_contents_all (struct value *);
-
-/* Like value_contents_all, but does not require that the returned
- bits be valid. This should only be used in situations where you
- plan to check the validity manually. */
-extern const gdb_byte *value_contents_for_printing (struct value *value);
-
-/* Like value_contents_for_printing, but accepts a constant value
- pointer. Unlike value_contents_for_printing however, the pointed
- value must _not_ be lazy. */
-extern const gdb_byte *
- value_contents_for_printing_const (const struct value *value);
-
-extern void value_fetch_lazy (struct value *val);
-
-/* If nonzero, this is the value of a variable which does not actually
- exist in the program, at least partially. If the value is lazy,
- this may fetch it now. */
-extern int value_optimized_out (struct value *value);
-
-/* Given a value, return true if any of the contents bits starting at
- OFFSET and extending for LENGTH bits is optimized out, false
- otherwise. */
-
-extern int value_bits_any_optimized_out (const struct value *value,
- int bit_offset, int bit_length);
-
-/* Like value_optimized_out, but return true iff the whole value is
- optimized out. */
-extern int value_entirely_optimized_out (struct value *value);
-
-/* Mark VALUE's content bytes starting at OFFSET and extending for
- LENGTH bytes as optimized out. */
-
-extern void mark_value_bytes_optimized_out (struct value *value,
- int offset, int length);
-
-/* Mark VALUE's content bits starting at OFFSET and extending for
- LENGTH bits as optimized out. */
-
-extern void mark_value_bits_optimized_out (struct value *value,
- LONGEST offset, LONGEST length);
-
-/* Set or return field indicating whether a variable is initialized or
- not, based on debugging information supplied by the compiler.
- 1 = initialized; 0 = uninitialized. */
-extern int value_initialized (const struct value *);
-extern void set_value_initialized (struct value *, int);
-
-/* Set COMPONENT's location as appropriate for a component of WHOLE
- --- regardless of what kind of lvalue WHOLE is. */
-extern void set_value_component_location (struct value *component,
- const struct value *whole);
-
-/* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
- single value might have multiple LVALs), this hacked interface is
- limited to just the first PIECE. Expect further change. */
-/* Type of value; either not an lval, or one of the various different
- possible kinds of lval. */
-extern enum lval_type *deprecated_value_lval_hack (struct value *);
-#define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
-
-/* Like VALUE_LVAL, except the parameter can be const. */
-extern enum lval_type value_lval_const (const struct value *value);
-
-/* If lval == lval_memory, return the address in the inferior. If
- lval == lval_register, return the byte offset into the registers
- structure. Otherwise, return 0. The returned address
- includes the offset, if any. */
-extern CORE_ADDR value_address (const struct value *);
-
-/* Like value_address, except the result does not include value's
- offset. */
-extern CORE_ADDR value_raw_address (const struct value *);
-
-/* Set the address of a value. */
-extern void set_value_address (struct value *, CORE_ADDR);
-
/* Pointer to internal variable. */
-extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
-#define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
+#define VALUE_INTERNALVAR(val) (*((val)->deprecated_internalvar_hack ()))
/* Frame ID of "next" frame to which a register value is relative. A
register value is indicated by VALUE_LVAL being set to lval_register.
So, if the register value is found relative to frame F, then the
frame id of F->next will be stored in VALUE_NEXT_FRAME_ID. */
-extern struct frame_id *deprecated_value_next_frame_id_hack (struct value *);
-#define VALUE_NEXT_FRAME_ID(val) (*deprecated_value_next_frame_id_hack (val))
-
-/* Frame ID of frame to which a register value is relative. This is
- similar to VALUE_NEXT_FRAME_ID, above, but may not be assigned to.
- Note that VALUE_FRAME_ID effectively undoes the "next" operation
- that was performed during the assignment to VALUE_NEXT_FRAME_ID. */
-#define VALUE_FRAME_ID(val) (get_prev_frame_id_by_id (VALUE_NEXT_FRAME_ID (val)))
+#define VALUE_NEXT_FRAME_ID(val) (*((val)->deprecated_next_frame_id_hack ()))
/* Register number if the value is from a register. */
-extern int *deprecated_value_regnum_hack (struct value *);
-#define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
+#define VALUE_REGNUM(val) (*((val)->deprecated_regnum_hack ()))
/* Return value after lval_funcs->coerce_ref (after check_typedef). Return
NULL if lval_funcs->coerce_ref is not applicable for whatever reason. */
extern struct value *coerce_array (struct value *value);
-/* Given a value, determine whether the bits starting at OFFSET and
- extending for LENGTH bits are a synthetic pointer. */
-
-extern int value_bits_synthetic_pointer (const struct value *value,
- LONGEST offset, LONGEST length);
-
-/* Given a value, determine whether the contents bytes starting at
- OFFSET and extending for LENGTH bytes are available. This returns
- nonzero if all bytes in the given range are available, zero if any
- byte is unavailable. */
-
-extern int value_bytes_available (const struct value *value,
- LONGEST offset, LONGEST length);
-
-/* Given a value, determine whether the contents bits starting at
- OFFSET and extending for LENGTH bits are available. This returns
- nonzero if all bits in the given range are available, zero if any
- bit is unavailable. */
-
-extern int value_bits_available (const struct value *value,
- LONGEST offset, LONGEST length);
-
-/* Like value_bytes_available, but return false if any byte in the
- whole object is unavailable. */
-extern int value_entirely_available (struct value *value);
-
-/* Like value_entirely_available, but return false if any byte in the
- whole object is available. */
-extern int value_entirely_unavailable (struct value *value);
-
-/* Mark VALUE's content bytes starting at OFFSET and extending for
- LENGTH bytes as unavailable. */
-
-extern void mark_value_bytes_unavailable (struct value *value,
- LONGEST offset, LONGEST length);
-
-/* Mark VALUE's content bits starting at OFFSET and extending for
- LENGTH bits as unavailable. */
-
-extern void mark_value_bits_unavailable (struct value *value,
- LONGEST offset, LONGEST length);
-
-/* Compare LENGTH bytes of VAL1's contents starting at OFFSET1 with
- LENGTH bytes of VAL2's contents starting at OFFSET2.
-
- Note that "contents" refers to the whole value's contents
- (value_contents_all), without any embedded offset adjustment. For
- example, to compare a complete object value with itself, including
- its enclosing type chunk, you'd do:
-
- int len = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
- value_contents_eq (val, 0, val, 0, len);
-
- Returns true iff the set of available/valid contents match.
-
- Optimized-out contents are equal to optimized-out contents, and are
- not equal to non-optimized-out contents.
-
- Unavailable contents are equal to unavailable contents, and are not
- equal to non-unavailable contents.
-
- For example, if 'x's represent an unavailable byte, and 'V' and 'Z'
- represent different available/valid bytes, in a value with length
- 16:
-
- offset: 0 4 8 12 16
- contents: xxxxVVVVxxxxVVZZ
-
- then:
-
- value_contents_eq(val, 0, val, 8, 6) => true
- value_contents_eq(val, 0, val, 4, 4) => false
- value_contents_eq(val, 0, val, 8, 8) => false
- value_contents_eq(val, 4, val, 12, 2) => true
- value_contents_eq(val, 4, val, 12, 4) => true
- value_contents_eq(val, 3, val, 4, 4) => true
-
- If 'x's represent an unavailable byte, 'o' represents an optimized
- out byte, in a value with length 8:
-
- offset: 0 4 8
- contents: xxxxoooo
-
- then:
-
- value_contents_eq(val, 0, val, 2, 2) => true
- value_contents_eq(val, 4, val, 6, 2) => true
- value_contents_eq(val, 0, val, 4, 4) => true
-
- We only know whether a value chunk is unavailable or optimized out
- if we've tried to read it. As this routine is used by printing
- routines, which may be printing values in the value history, long
- after the inferior is gone, it works with const values. Therefore,
- this routine must not be called with lazy values. */
-
-extern bool value_contents_eq (const struct value *val1, LONGEST offset1,
- const struct value *val2, LONGEST offset2,
- LONGEST length);
-
/* Read LENGTH addressable memory units starting at MEMADDR into BUFFER,
which is (or will be copied to) VAL's contents buffer offset by
BIT_OFFSET bits. Marks value contents ranges as unavailable if
whether the memory is known to be stack memory. */
extern void read_value_memory (struct value *val, LONGEST bit_offset,
- int stack, CORE_ADDR memaddr,
+ bool stack, CORE_ADDR memaddr,
gdb_byte *buffer, size_t length);
/* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
#include "gdbtypes.h"
#include "expression.h"
-struct frame_info;
+class frame_info_ptr;
struct fn_field;
extern int print_address_demangle (const struct value_print_options *,
extern LONGEST value_as_long (struct value *val);
extern CORE_ADDR value_as_address (struct value *val);
+/* Extract the value from VAL as a MPZ. This coerces arrays and
+ handles various integer-like types as well. */
+
+extern gdb_mpz value_as_mpz (struct value *val);
+
extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
LONGEST embedded_offset, int fieldno,
const struct value *val, LONGEST *result);
-extern void unpack_value_bitfield (struct value *dest_val,
- LONGEST bitpos, LONGEST bitsize,
- const gdb_byte *valaddr,
- LONGEST embedded_offset,
- const struct value *val);
-
extern struct value *value_field_bitfield (struct type *type, int fieldno,
const gdb_byte *valaddr,
LONGEST embedded_offset,
extern struct value *value_from_component (struct value *, struct type *,
LONGEST);
+/* Convert the value V into a newly allocated value. */
+extern struct value *value_from_mpz (struct type *type, const gdb_mpz &v);
+
extern struct value *value_at (struct type *type, CORE_ADDR addr);
-extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
+
+/* Return a new value given a type and an address. The new value is
+ lazy. If FRAME is given, it is used when resolving dynamic
+ properties. */
+
+extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr,
+ frame_info_ptr frame = nullptr);
+
+/* Like value_at, but ensures that the result is marked not_lval.
+ This can be important if the memory is "volatile". */
+extern struct value *value_at_non_lval (struct type *type, CORE_ADDR addr);
extern struct value *value_from_contents_and_address_unresolved
(struct type *, const gdb_byte *, CORE_ADDR);
-extern struct value *value_from_contents_and_address (struct type *,
- const gdb_byte *,
- CORE_ADDR);
+extern struct value *value_from_contents_and_address
+ (struct type *, const gdb_byte *, CORE_ADDR,
+ frame_info_ptr frame = nullptr);
extern struct value *value_from_contents (struct type *, const gdb_byte *);
extern struct value *default_value_from_register (struct gdbarch *gdbarch,
struct frame_id frame_id);
extern void read_frame_register_value (struct value *value,
- struct frame_info *frame);
+ frame_info_ptr frame);
extern struct value *value_from_register (struct type *type, int regnum,
- struct frame_info *frame);
+ frame_info_ptr frame);
extern CORE_ADDR address_from_register (int regnum,
- struct frame_info *frame);
+ frame_info_ptr frame);
extern struct value *value_of_variable (struct symbol *var,
const struct block *b);
extern struct value *address_of_variable (struct symbol *var,
const struct block *b);
-extern struct value *value_of_register (int regnum, struct frame_info *frame);
+extern struct value *value_of_register (int regnum, frame_info_ptr frame);
-struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
+struct value *value_of_register_lazy (frame_info_ptr frame, int regnum);
/* Return the symbol's reading requirement. */
extern struct value *read_var_value (struct symbol *var,
const struct block *var_block,
- struct frame_info *frame);
-
-extern struct value *allocate_value (struct type *type);
-extern struct value *allocate_value_lazy (struct type *type);
-extern void value_contents_copy (struct value *dst, LONGEST dst_offset,
- struct value *src, LONGEST src_offset,
- LONGEST length);
+ frame_info_ptr frame);
extern struct value *allocate_repeat_value (struct type *type, int count);
/* Free the values currently on the value stack. */
void free_to_mark ()
{
- if (m_value != NULL)
+ if (!m_freed)
{
value_free_to_mark (m_value);
- m_value = NULL;
+ m_freed = true;
}
}
private:
const struct value *m_value;
+ bool m_freed = false;
};
-extern struct value *value_cstring (const char *ptr, ssize_t len,
+/* Create not_lval value representing a NULL-terminated C string. The
+ resulting value has type TYPE_CODE_ARRAY. The string passed in should
+ not include embedded null characters.
+
+ PTR points to the string data; COUNT is number of characters (does
+ not include the NULL terminator) pointed to by PTR, each character is of
+ type (and size of) CHAR_TYPE. */
+
+extern struct value *value_cstring (const gdb_byte *ptr, ssize_t count,
struct type *char_type);
-extern struct value *value_string (const char *ptr, ssize_t len,
+
+/* Specialisation of value_cstring above. In this case PTR points to
+ single byte characters. CHAR_TYPE must have a length of 1. */
+inline struct value *value_cstring (const char *ptr, ssize_t count,
+ struct type *char_type)
+{
+ gdb_assert (char_type->length () == 1);
+ return value_cstring ((const gdb_byte *) ptr, count, char_type);
+}
+
+/* Create a not_lval value with type TYPE_CODE_STRING, the resulting value
+ has type TYPE_CODE_STRING.
+
+ PTR points to the string data; COUNT is number of characters pointed to
+ by PTR, each character has the type (and size of) CHAR_TYPE.
+
+ Note that string types are like array of char types with a lower bound
+ defined by the language (usually zero or one). Also the string may
+ contain embedded null characters. */
+
+extern struct value *value_string (const gdb_byte *ptr, ssize_t count,
struct type *char_type);
+/* Specialisation of value_string above. In this case PTR points to
+ single byte characters. CHAR_TYPE must have a length of 1. */
+inline struct value *value_string (const char *ptr, ssize_t count,
+ struct type *char_type)
+{
+ gdb_assert (char_type->length () == 1);
+ return value_string ((const gdb_byte *) ptr, count, char_type);
+}
+
extern struct value *value_array (int lowbound, int highbound,
struct value **elemvec);
extern struct value *value_assign (struct value *toval,
struct value *fromval);
+/* The unary + operation. */
extern struct value *value_pos (struct value *arg1);
+/* The unary - operation. */
extern struct value *value_neg (struct value *arg1);
+/* The unary ~ operation -- but note that it also implements the GCC
+ extension, where ~ of a complex number is the complex
+ conjugate. */
extern struct value *value_complement (struct value *arg1);
extern struct value *value_struct_elt (struct value **argp,
extern struct value *value_field (struct value *arg1, int fieldno);
-extern struct value *value_primitive_field (struct value *arg1, LONGEST offset,
- int fieldno,
- struct type *arg_type);
-
-
extern struct type *value_rtti_indirect_type (struct value *, int *, LONGEST *,
int *);
extern struct value *value_dynamic_cast (struct type *type, struct value *arg);
-extern struct value *value_zero (struct type *type, enum lval_type lv);
-
extern struct value *value_one (struct type *type);
extern struct value *value_repeat (struct value *arg1, int count);
extern struct value *register_value_being_returned (struct type *valtype,
struct regcache *retbuf);
-extern int value_in (struct value *element, struct value *set);
-
extern int value_bit_index (struct type *type, const gdb_byte *addr,
int index);
struct value *function,
struct type *value_type);
-/* Evaluate the expression EXP. If set, EXPECT_TYPE is passed to the
- outermost operation's evaluation. This is ignored by most
- operations, but may be used, e.g., to determine the type of an
- otherwise untyped symbol. The caller should not assume that the
- returned value has this type. */
-
-extern struct value *evaluate_expression (struct expression *exp,
- struct type *expect_type = nullptr);
-
-extern struct value *evaluate_type (struct expression *exp);
-
extern value *evaluate_var_value (enum noside noside, const block *blk,
symbol *var);
std::vector<value_ref_ptr> *val_chain,
bool preserve_errors);
-extern struct value *parse_and_eval (const char *exp);
+extern struct value *parse_and_eval (const char *exp, parser_flags flags = 0);
extern struct value *parse_to_comma_and_eval (const char **expp);
extern struct value *access_value_history (int num);
+/* Return the number of items in the value history. */
+
+extern ULONGEST value_history_count ();
+
extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
struct internalvar *var);
struct agent_expr *expr,
struct axs_value *value,
void *data);
-
- /* If non-NULL, this is called to destroy DATA. The DATA argument
- passed to this function is the same argument that was passed to
- `create_internalvar_type_lazy'. */
-
- void (*destroy) (void *data);
};
extern struct internalvar *create_internalvar_type_lazy (const char *name,
extern int value_less (struct value *arg1, struct value *arg2);
-extern int value_logical_not (struct value *arg1);
+/* Simulate the C operator ! -- return true if ARG1 contains zero. */
+extern bool value_logical_not (struct value *arg1);
+
+/* Returns true if the value VAL represents a true value. */
+static inline bool
+value_true (struct value *val)
+{
+ return !value_logical_not (val);
+}
/* C++ */
extern value_ref_ptr release_value (struct value *val);
-extern int record_latest_value (struct value *val);
-
extern void modify_field (struct type *type, gdb_byte *addr,
LONGEST fieldval, LONGEST bitpos, LONGEST bitsize);
extern void value_print (struct value *val, struct ui_file *stream,
const struct value_print_options *options);
-extern void value_print_array_elements (struct value *val,
- struct ui_file *stream, int format,
- enum val_prettyformat pretty);
-
/* Release values from the value chain and return them. Values
created after MARK are released. If MARK is nullptr, or if MARK is
not found on the value chain, then all values are released. Values
extern void print_variable_and_value (const char *name,
struct symbol *var,
- struct frame_info *frame,
+ frame_info_ptr frame,
struct ui_file *stream,
int indent);
/* From values.c */
-extern struct value *value_copy (struct value *);
-
-extern struct value *value_non_lval (struct value *);
-
-extern void value_force_lval (struct value *, CORE_ADDR);
-
extern struct value *make_cv_value (int, int, struct value *);
-extern void preserve_one_value (struct value *, struct objfile *, htab_t);
-
/* From valops.c */
extern struct value *varying_to_slice (struct value *);
extern struct value *value_allocate_space_in_inferior (int);
-extern struct value *value_subscripted_rvalue (struct value *array,
- LONGEST index,
- LONGEST lowerbound);
-
/* User function handler. */
typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch,
const char *value_internal_function_name (struct value *);
-/* Build a value wrapping and representing WORKER. The value takes ownership
- of the xmethod_worker object. */
-
-extern struct value *value_from_xmethod (xmethod_worker_up &&worker);
-
-extern struct type *result_type_of_xmethod (struct value *method,
- gdb::array_view<value *> argv);
-
-extern struct value *call_xmethod (struct value *method,
- gdb::array_view<value *> argv);
-
/* Destroy the values currently allocated. This is called when GDB is
exiting (e.g., on quit_force). */
extern void finalize_values ();
of floating-point, fixed-point, or integer type. */
extern gdb_mpq value_to_gdb_mpq (struct value *value);
+/* Return true if LEN (in bytes) exceeds the max-value-size setting,
+ otherwise, return false. If the user has disabled (set to unlimited)
+ the max-value-size setting then this function will always return false. */
+extern bool exceeds_max_value_size (ULONGEST length);
+
+/* While an instance of this class is live, and array values that are
+ created, that are larger than max_value_size, will be restricted in size
+ to a particular number of elements. */
+
+struct scoped_array_length_limiting
+{
+ /* Limit any large array values to only contain ELEMENTS elements. */
+ scoped_array_length_limiting (int elements);
+
+ /* Restore the previous array value limit. */
+ ~scoped_array_length_limiting ();
+
+private:
+ /* Used to hold the previous array value element limit. */
+ gdb::optional<int> m_old_value;
+};
+
#endif /* !defined (VALUE_H) */
projects / binutils-gdb.git / blobdiff