0936ad1d22
* ax-gdb.h (gen_trace_for_var): Declare. * ax-gdb.c (gen_trace_for_var): New function. * dwarf2loc.c (dwarf_expr_frame_base_1): New function, split from... (dwarf_expr_frame_base): ...here. (dwarf2_tracepoint_var_ref): Add computed location case. * tracepoint.c (collect_symbol): Add scope arg and LOC_COMPUTED case. (add_local_symbols): Update call to collect_symbol. (encode_actions): Ditto.
107 lines
4.1 KiB
C
107 lines
4.1 KiB
C
/* GDB-specific functions for operating on agent expressions
|
||
Copyright (C) 1998, 1999, 2000, 2007, 2008, 2009
|
||
Free Software Foundation, Inc.
|
||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 3 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||
|
||
#ifndef AX_GDB_H
|
||
#define AX_GDB_H
|
||
|
||
struct expression;
|
||
|
||
/* Types and enums */
|
||
|
||
/* GDB stores expressions in the form of a flattened tree (struct
|
||
expression), so we just walk that tree and generate agent bytecodes
|
||
as we go along.
|
||
|
||
GDB's normal evaluation uses struct value, which contains the
|
||
expression's value as well as its address or the register it came
|
||
from. The `+' operator uses the value, whereas the unary `&'
|
||
operator will use the address portion. The `=' operator will use
|
||
the address or register number of its left hand side.
|
||
|
||
The issues are different when generating agent bytecode. Given a
|
||
variable reference expression, we should not necessarily generate
|
||
code to fetch its value, because the next operator may be `=' or
|
||
unary `&'. Instead, when we recurse on a subexpression, we
|
||
indicate whether we want that expression to produce an lvalue or an
|
||
rvalue. If we requested an lvalue, then the recursive call tells
|
||
us whether it generated code to compute an address on the stack, or
|
||
whether the lvalue lives in a register.
|
||
|
||
The `axs' prefix here means `agent expression, static', because
|
||
this is all static analysis of the expression, i.e. analysis which
|
||
doesn't depend on the contents of memory and registers. */
|
||
|
||
|
||
/* Different kinds of agent expression static values. */
|
||
enum axs_lvalue_kind
|
||
{
|
||
/* We generated code to compute the subexpression's value.
|
||
Constants and arithmetic operators yield this. */
|
||
axs_rvalue,
|
||
|
||
/* We generated code to yield the subexpression's value's address on
|
||
the top of the stack. If the caller needs an rvalue, it should
|
||
call require_rvalue to produce the rvalue from this address. */
|
||
axs_lvalue_memory,
|
||
|
||
/* We didn't generate any code, and the stack is undisturbed,
|
||
because the subexpression's value lives in a register; u.reg is
|
||
the register number. If the caller needs an rvalue, it should
|
||
call require_rvalue to produce the rvalue from this register
|
||
number. */
|
||
axs_lvalue_register
|
||
};
|
||
|
||
/* Structure describing what we got from a subexpression. Think of
|
||
this as parallel to value.h's enum lval_type, except that we're
|
||
describing a value which will exist when the expression is
|
||
evaluated in the future, not a value we have in our hand. */
|
||
struct axs_value
|
||
{
|
||
enum axs_lvalue_kind kind; /* see above */
|
||
|
||
/* The type of the subexpression. Even if lvalue == axs_lvalue_memory,
|
||
this is the type of the value itself; the value on the stack is a
|
||
"pointer to" an object of this type. */
|
||
struct type *type;
|
||
|
||
union
|
||
{
|
||
/* if kind == axs_lvalue_register, this is the register number */
|
||
int reg;
|
||
}
|
||
u;
|
||
};
|
||
|
||
|
||
/* Translating GDB expressions into agent expressions. */
|
||
|
||
/* Given a GDB expression EXPR, return bytecode to trace its value.
|
||
The result will use the `trace' and `trace_quick' bytecodes to
|
||
record the value of all memory touched by the expression, and leave
|
||
no values on the stack. The caller can then use the ax_reqs
|
||
function to discover which registers the expression uses. */
|
||
extern struct agent_expr *gen_trace_for_expr (CORE_ADDR, struct expression *);
|
||
|
||
extern struct agent_expr *gen_trace_for_var (CORE_ADDR, struct symbol *);
|
||
|
||
extern struct agent_expr *gen_eval_for_expr (CORE_ADDR, struct expression *);
|
||
|
||
#endif /* AX_GDB_H */
|