298 lines
10 KiB
C
298 lines
10 KiB
C
/* DWARF 2 Expression Evaluator.
|
|
|
|
Copyright (C) 2001-2003, 2005, 2007-2012 Free Software Foundation,
|
|
Inc.
|
|
|
|
Contributed by Daniel Berlin <dan@dberlin.org>.
|
|
|
|
This file is part of GDB.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#if !defined (DWARF2EXPR_H)
|
|
#define DWARF2EXPR_H
|
|
|
|
struct dwarf_expr_context;
|
|
|
|
/* Virtual method table for struct dwarf_expr_context below. */
|
|
|
|
struct dwarf_expr_context_funcs
|
|
{
|
|
/* Return the value of register number REGNUM. */
|
|
CORE_ADDR (*read_reg) (void *baton, int regnum);
|
|
|
|
/* Read LENGTH bytes at ADDR into BUF. */
|
|
void (*read_mem) (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t length);
|
|
|
|
/* Return the location expression for the frame base attribute, in
|
|
START and LENGTH. The result must be live until the current
|
|
expression evaluation is complete. */
|
|
void (*get_frame_base) (void *baton, const gdb_byte **start, size_t *length);
|
|
|
|
/* Return the CFA for the frame. */
|
|
CORE_ADDR (*get_frame_cfa) (void *baton);
|
|
|
|
/* Return the PC for the frame. */
|
|
CORE_ADDR (*get_frame_pc) (void *baton);
|
|
|
|
/* Return the thread-local storage address for
|
|
DW_OP_GNU_push_tls_address. */
|
|
CORE_ADDR (*get_tls_address) (void *baton, CORE_ADDR offset);
|
|
|
|
/* Execute DW_AT_location expression for the DWARF expression subroutine in
|
|
the DIE at DIE_OFFSET in the CU from CTX. Do not touch STACK while it
|
|
being passed to and returned from the called DWARF subroutine. */
|
|
void (*dwarf_call) (struct dwarf_expr_context *ctx, size_t die_offset);
|
|
|
|
/* Return the base type given by the indicated DIE. This can throw
|
|
an exception if the DIE is invalid or does not represent a base
|
|
type. If can also be NULL in the special case where the
|
|
callbacks are not performing evaluation, and thus it is
|
|
meaningful to substitute a stub type of the correct size. */
|
|
struct type *(*get_base_type) (struct dwarf_expr_context *ctx, size_t die);
|
|
|
|
/* Push on DWARF stack an entry evaluated for DW_TAG_GNU_call_site's
|
|
DWARF_REG/FB_OFFSET at the caller of specified BATON. If DWARF register
|
|
number DWARF_REG specifying the push_dwarf_reg_entry_value parameter is
|
|
not -1 FB_OFFSET is ignored. Otherwise FB_OFFSET specifies stack
|
|
parameter offset against caller's stack pointer (which equals the callee's
|
|
frame base). If DEREF_SIZE is not -1 then use
|
|
DW_AT_GNU_call_site_data_value instead of DW_AT_GNU_call_site_value. */
|
|
void (*push_dwarf_reg_entry_value) (struct dwarf_expr_context *ctx,
|
|
int dwarf_reg, CORE_ADDR fb_offset,
|
|
int deref_size);
|
|
|
|
#if 0
|
|
/* Not yet implemented. */
|
|
|
|
/* Return the `object address' for DW_OP_push_object_address. */
|
|
CORE_ADDR (*get_object_address) (void *baton);
|
|
#endif
|
|
};
|
|
|
|
/* The location of a value. */
|
|
enum dwarf_value_location
|
|
{
|
|
/* The piece is in memory.
|
|
The value on the dwarf stack is its address. */
|
|
DWARF_VALUE_MEMORY,
|
|
|
|
/* The piece is in a register.
|
|
The value on the dwarf stack is the register number. */
|
|
DWARF_VALUE_REGISTER,
|
|
|
|
/* The piece is on the dwarf stack. */
|
|
DWARF_VALUE_STACK,
|
|
|
|
/* The piece is a literal. */
|
|
DWARF_VALUE_LITERAL,
|
|
|
|
/* The piece was optimized out. */
|
|
DWARF_VALUE_OPTIMIZED_OUT,
|
|
|
|
/* The piece is an implicit pointer. */
|
|
DWARF_VALUE_IMPLICIT_POINTER
|
|
};
|
|
|
|
/* The dwarf expression stack. */
|
|
|
|
struct dwarf_stack_value
|
|
{
|
|
struct value *value;
|
|
|
|
/* Non-zero if the piece is in memory and is known to be
|
|
on the program's stack. It is always ok to set this to zero.
|
|
This is used, for example, to optimize memory access from the target.
|
|
It can vastly speed up backtraces on long latency connections when
|
|
"set stack-cache on". */
|
|
int in_stack_memory;
|
|
};
|
|
|
|
/* The expression evaluator works with a dwarf_expr_context, describing
|
|
its current state and its callbacks. */
|
|
struct dwarf_expr_context
|
|
{
|
|
/* The stack of values, allocated with xmalloc. */
|
|
struct dwarf_stack_value *stack;
|
|
|
|
/* The number of values currently pushed on the stack, and the
|
|
number of elements allocated to the stack. */
|
|
int stack_len, stack_allocated;
|
|
|
|
/* Target architecture to use for address operations. */
|
|
struct gdbarch *gdbarch;
|
|
|
|
/* Target address size in bytes. */
|
|
int addr_size;
|
|
|
|
/* DW_FORM_ref_addr size in bytes. If -1 DWARF is executed from a frame
|
|
context and operations depending on DW_FORM_ref_addr are not allowed. */
|
|
int ref_addr_size;
|
|
|
|
/* Offset used to relocate DW_OP_addr argument. */
|
|
CORE_ADDR offset;
|
|
|
|
/* An opaque argument provided by the caller, which will be passed
|
|
to all of the callback functions. */
|
|
void *baton;
|
|
|
|
/* Callback functions. */
|
|
const struct dwarf_expr_context_funcs *funcs;
|
|
|
|
/* The current depth of dwarf expression recursion, via DW_OP_call*,
|
|
DW_OP_fbreg, DW_OP_push_object_address, etc., and the maximum
|
|
depth we'll tolerate before raising an error. */
|
|
int recursion_depth, max_recursion_depth;
|
|
|
|
/* Location of the value. */
|
|
enum dwarf_value_location location;
|
|
|
|
/* For DWARF_VALUE_LITERAL, the current literal value's length and
|
|
data. For DWARF_VALUE_IMPLICIT_POINTER, LEN is the offset of the
|
|
target DIE. */
|
|
ULONGEST len;
|
|
const gdb_byte *data;
|
|
|
|
/* Initialization status of variable: Non-zero if variable has been
|
|
initialized; zero otherwise. */
|
|
int initialized;
|
|
|
|
/* An array of pieces. PIECES points to its first element;
|
|
NUM_PIECES is its length.
|
|
|
|
Each time DW_OP_piece is executed, we add a new element to the
|
|
end of this array, recording the current top of the stack, the
|
|
current location, and the size given as the operand to
|
|
DW_OP_piece. We then pop the top value from the stack, reset the
|
|
location, and resume evaluation.
|
|
|
|
The Dwarf spec doesn't say whether DW_OP_piece pops the top value
|
|
from the stack. We do, ensuring that clients of this interface
|
|
expecting to see a value left on the top of the stack (say, code
|
|
evaluating frame base expressions or CFA's specified with
|
|
DW_CFA_def_cfa_expression) will get an error if the expression
|
|
actually marks all the values it computes as pieces.
|
|
|
|
If an expression never uses DW_OP_piece, num_pieces will be zero.
|
|
(It would be nice to present these cases as expressions yielding
|
|
a single piece, so that callers need not distinguish between the
|
|
no-DW_OP_piece and one-DW_OP_piece cases. But expressions with
|
|
no DW_OP_piece operations have no value to place in a piece's
|
|
'size' field; the size comes from the surrounding data. So the
|
|
two cases need to be handled separately.) */
|
|
int num_pieces;
|
|
struct dwarf_expr_piece *pieces;
|
|
};
|
|
|
|
|
|
/* A piece of an object, as recorded by DW_OP_piece or DW_OP_bit_piece. */
|
|
struct dwarf_expr_piece
|
|
{
|
|
enum dwarf_value_location location;
|
|
|
|
union
|
|
{
|
|
struct
|
|
{
|
|
/* This piece's address, for DWARF_VALUE_MEMORY pieces. */
|
|
CORE_ADDR addr;
|
|
/* Non-zero if the piece is known to be in memory and on
|
|
the program's stack. */
|
|
int in_stack_memory;
|
|
} mem;
|
|
|
|
/* The piece's register number, for DWARF_VALUE_REGISTER pieces. */
|
|
int regno;
|
|
|
|
/* The piece's literal value, for DWARF_VALUE_STACK pieces. */
|
|
struct value *value;
|
|
|
|
struct
|
|
{
|
|
/* A pointer to the data making up this piece,
|
|
for DWARF_VALUE_LITERAL pieces. */
|
|
const gdb_byte *data;
|
|
/* The length of the available data. */
|
|
ULONGEST length;
|
|
} literal;
|
|
|
|
/* Used for DWARF_VALUE_IMPLICIT_POINTER. */
|
|
struct
|
|
{
|
|
/* The referent DIE from DW_OP_GNU_implicit_pointer. */
|
|
ULONGEST die;
|
|
/* The byte offset into the resulting data. */
|
|
LONGEST offset;
|
|
} ptr;
|
|
} v;
|
|
|
|
/* The length of the piece, in bits. */
|
|
ULONGEST size;
|
|
/* The piece offset, in bits. */
|
|
ULONGEST offset;
|
|
};
|
|
|
|
struct dwarf_expr_context *new_dwarf_expr_context (void);
|
|
void free_dwarf_expr_context (struct dwarf_expr_context *ctx);
|
|
struct cleanup *
|
|
make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx);
|
|
|
|
void dwarf_expr_push_address (struct dwarf_expr_context *ctx,
|
|
CORE_ADDR value,
|
|
int in_stack_memory);
|
|
void dwarf_expr_eval (struct dwarf_expr_context *ctx, const gdb_byte *addr,
|
|
size_t len);
|
|
struct value *dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n);
|
|
CORE_ADDR dwarf_expr_fetch_address (struct dwarf_expr_context *ctx, int n);
|
|
int dwarf_expr_fetch_in_stack_memory (struct dwarf_expr_context *ctx, int n);
|
|
|
|
|
|
const gdb_byte *read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end,
|
|
ULONGEST * r);
|
|
const gdb_byte *read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end,
|
|
LONGEST * r);
|
|
|
|
const char *dwarf_stack_op_name (unsigned int);
|
|
|
|
void dwarf_expr_require_composition (const gdb_byte *, const gdb_byte *,
|
|
const char *);
|
|
|
|
/* Stub dwarf_expr_context_funcs implementations. */
|
|
|
|
void ctx_no_get_frame_base (void *baton, const gdb_byte **start,
|
|
size_t *length);
|
|
CORE_ADDR ctx_no_get_frame_cfa (void *baton);
|
|
CORE_ADDR ctx_no_get_frame_pc (void *baton);
|
|
CORE_ADDR ctx_no_get_tls_address (void *baton, CORE_ADDR offset);
|
|
void ctx_no_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset);
|
|
struct type *ctx_no_get_base_type (struct dwarf_expr_context *ctx, size_t die);
|
|
void ctx_no_push_dwarf_reg_entry_value (struct dwarf_expr_context *ctx,
|
|
int dwarf_reg, CORE_ADDR fb_offset,
|
|
int deref_size);
|
|
|
|
int dwarf_block_to_dwarf_reg (const gdb_byte *buf, const gdb_byte *buf_end);
|
|
|
|
int dwarf_block_to_dwarf_reg_deref (const gdb_byte *buf,
|
|
const gdb_byte *buf_end,
|
|
CORE_ADDR *deref_size_return);
|
|
|
|
int dwarf_block_to_fb_offset (const gdb_byte *buf, const gdb_byte *buf_end,
|
|
CORE_ADDR *fb_offset_return);
|
|
|
|
int dwarf_block_to_sp_offset (struct gdbarch *gdbarch, const gdb_byte *buf,
|
|
const gdb_byte *buf_end,
|
|
CORE_ADDR *sp_offset_return);
|
|
|
|
#endif /* dwarf2expr.h */
|