/* GDB-specific functions for operating on agent expressions.
- Copyright (C) 1998-2013 Free Software Foundation, Inc.
+ Copyright (C) 1998-2014 Free Software Foundation, Inc.
This file is part of GDB.
#include "target.h"
#include "ax.h"
#include "ax-gdb.h"
-#include "gdb_string.h"
+#include <string.h>
#include "block.h"
#include "regcache.h"
#include "user-regs.h"
sizes), and this is simpler.) */
\f
-/* Generating bytecode from GDB expressions: the `trace' kludge */
-
-/* The compiler in this file is a general-purpose mechanism for
- translating GDB expressions into bytecode. One ought to be able to
- find a million and one uses for it.
-
- However, at the moment it is HOPELESSLY BRAIN-DAMAGED for the sake
- of expediency. Let he who is without sin cast the first stone.
-
- For the data tracing facility, we need to insert `trace' bytecodes
- before each data fetch; this records all the memory that the
- expression touches in the course of evaluation, so that memory will
- be available when the user later tries to evaluate the expression
- in GDB.
-
- This should be done (I think) in a post-processing pass, that walks
- an arbitrary agent expression and inserts `trace' operations at the
- appropriate points. But it's much faster to just hack them
- directly into the code. And since we're in a crunch, that's what
- I've done.
-
- Setting the flag trace_kludge to non-zero enables the code that
- emits the trace bytecodes at the appropriate points. */
-int trace_kludge;
-
-/* Inspired by trace_kludge, this indicates that pointers to chars
- should get an added tracenz bytecode to record nonzero bytes, up to
- a length that is the value of trace_string_kludge. */
-int trace_string_kludge;
-
/* Scan for all static fields in the given class, including any base
classes, and generate tracing bytecodes for each. */
struct agent_expr *ax, struct axs_value *value)
{
int string_trace = 0;
- if (trace_string_kludge
+ if (ax->trace_string
&& TYPE_CODE (value->type) == TYPE_CODE_PTR
&& c_textual_element_type (check_typedef (TYPE_TARGET_TYPE (value->type)),
's'))
string_trace = 1;
- if (trace_kludge)
+ if (ax->tracing)
switch (value->kind)
{
case axs_rvalue:
if (string_trace)
{
- ax_const_l (ax, trace_string_kludge);
+ ax_const_l (ax, ax->trace_string);
ax_simple (ax, aop_tracenz);
}
else
if (string_trace)
{
ax_simple (ax, aop_ref32);
- ax_const_l (ax, trace_string_kludge);
+ ax_const_l (ax, ax->trace_string);
ax_simple (ax, aop_tracenz);
}
}
if (string_trace)
{
ax_reg (ax, value->u.reg);
- ax_const_l (ax, trace_string_kludge);
+ ax_const_l (ax, ax->trace_string);
ax_simple (ax, aop_tracenz);
}
break;
ax_simple (ax, aop_pop);
/* To trace C++ classes with static fields stored elsewhere. */
- if (trace_kludge
+ if (ax->tracing
&& (TYPE_CODE (value->type) == TYPE_CODE_STRUCT
|| TYPE_CODE (value->type) == TYPE_CODE_UNION))
gen_trace_static_fields (gdbarch, ax, value->type);
static void
gen_fetch (struct agent_expr *ax, struct type *type)
{
- if (trace_kludge)
+ if (ax->tracing)
{
/* Record the area of memory we're about to fetch. */
ax_trace_quick (ax, TYPE_LENGTH (type));
value->type = check_typedef (SYMBOL_TYPE (var));
value->optimized_out = 0;
+ if (SYMBOL_COMPUTED_OPS (var) != NULL)
+ {
+ SYMBOL_COMPUTED_OPS (var)->tracepoint_var_ref (var, gdbarch, ax, value);
+ return;
+ }
+
/* I'm imitating the code in read_var_value. */
switch (SYMBOL_CLASS (var))
{
break;
case LOC_COMPUTED:
- /* FIXME: cagney/2004-01-26: It should be possible to
- unconditionally call the SYMBOL_COMPUTED_OPS method when available.
- Unfortunately DWARF 2 stores the frame-base (instead of the
- function) location in a function's symbol. Oops! For the
- moment enable this when/where applicable. */
- SYMBOL_COMPUTED_OPS (var)->tracepoint_var_ref (var, gdbarch, ax, value);
- break;
+ gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
case LOC_OPTIMIZED_OUT:
/* Flag this, but don't say anything; leave it up to callers to
/* Add the offset. */
gen_offset (ax, offset / TARGET_CHAR_BIT);
- if (trace_kludge)
+ if (ax->tracing)
{
/* Record the area of memory we're about to fetch. */
ax_trace_quick (ax, op_size / TARGET_CHAR_BIT);
if (tsv)
{
ax_tsv (ax, aop_setv, tsv->number);
- if (trace_kludge)
+ if (ax->tracing)
ax_tsv (ax, aop_tracev, tsv->number);
}
else
{
/* The tsv will be the left half of the binary operation. */
ax_tsv (ax, aop_getv, tsv->number);
- if (trace_kludge)
+ if (ax->tracing)
ax_tsv (ax, aop_tracev, tsv->number);
/* Trace state variables are always 64-bit integers. */
value1.kind = axs_rvalue;
gen_expr_binop_rest (exp, op2, pc, ax, value, &value1, &value2);
/* We have a result of the binary op, set the tsv. */
ax_tsv (ax, aop_setv, tsv->number);
- if (trace_kludge)
+ if (ax->tracing)
ax_tsv (ax, aop_tracev, tsv->number);
}
else
if (tsv)
{
ax_tsv (ax, aop_getv, tsv->number);
- if (trace_kludge)
+ if (ax->tracing)
ax_tsv (ax, aop_tracev, tsv->number);
/* Trace state variables are always 64-bit integers. */
value->kind = axs_rvalue;
struct agent_expr *
gen_trace_for_var (CORE_ADDR scope, struct gdbarch *gdbarch,
- struct symbol *var)
+ struct symbol *var, int trace_string)
{
struct cleanup *old_chain = 0;
struct agent_expr *ax = new_agent_expr (gdbarch, scope);
old_chain = make_cleanup_free_agent_expr (ax);
- trace_kludge = 1;
+ ax->tracing = 1;
+ ax->trace_string = trace_string;
gen_var_ref (gdbarch, ax, &value, var);
/* If there is no actual variable to trace, flag it by returning
caller can then use the ax_reqs function to discover which
registers it relies upon. */
struct agent_expr *
-gen_trace_for_expr (CORE_ADDR scope, struct expression *expr)
+gen_trace_for_expr (CORE_ADDR scope, struct expression *expr,
+ int trace_string)
{
struct cleanup *old_chain = 0;
struct agent_expr *ax = new_agent_expr (expr->gdbarch, scope);
old_chain = make_cleanup_free_agent_expr (ax);
pc = expr->elts;
- trace_kludge = 1;
+ ax->tracing = 1;
+ ax->trace_string = trace_string;
value.optimized_out = 0;
gen_expr (expr, &pc, ax, &value);
old_chain = make_cleanup_free_agent_expr (ax);
pc = expr->elts;
- trace_kludge = 0;
+ ax->tracing = 0;
value.optimized_out = 0;
gen_expr (expr, &pc, ax, &value);
}
struct agent_expr *
-gen_trace_for_return_address (CORE_ADDR scope, struct gdbarch *gdbarch)
+gen_trace_for_return_address (CORE_ADDR scope, struct gdbarch *gdbarch,
+ int trace_string)
{
struct cleanup *old_chain = 0;
struct agent_expr *ax = new_agent_expr (gdbarch, scope);
old_chain = make_cleanup_free_agent_expr (ax);
- trace_kludge = 1;
+ ax->tracing = 1;
+ ax->trace_string = trace_string;
gdbarch_gen_return_address (gdbarch, ax, &value, scope);
old_chain = make_cleanup_free_agent_expr (ax);
+ /* We're computing values, not doing side effects. */
+ ax->tracing = 0;
+
/* Evaluate and push the args on the stack in reverse order,
for simplicity of collecting them on the target side. */
for (tem = nargs - 1; tem >= 0; --tem)
{
pc = exprs[tem]->elts;
- /* We're computing values, not doing side effects. */
- trace_kludge = 0;
value.optimized_out = 0;
gen_expr (exprs[tem], &pc, ax, &value);
require_rvalue (ax, &value);
}
static void
-agent_eval_command_one (char *exp, int eval, CORE_ADDR pc)
+agent_eval_command_one (const char *exp, int eval, CORE_ADDR pc)
{
struct cleanup *old_chain = 0;
struct expression *expr;
struct agent_expr *agent;
const char *arg;
+ int trace_string = 0;
if (!eval)
{
- trace_string_kludge = 0;
if (*exp == '/')
- exp = decode_agent_options (exp);
+ exp = decode_agent_options (exp, &trace_string);
}
arg = exp;
if (!eval && strcmp (arg, "$_ret") == 0)
{
- agent = gen_trace_for_return_address (pc, get_current_arch ());
+ agent = gen_trace_for_return_address (pc, get_current_arch (),
+ trace_string);
old_chain = make_cleanup_free_agent_expr (agent);
}
else
expr = parse_exp_1 (&arg, pc, block_for_pc (pc), 0);
old_chain = make_cleanup (free_current_contents, &expr);
if (eval)
- agent = gen_eval_for_expr (pc, expr);
+ {
+ gdb_assert (trace_string == 0);
+ agent = gen_eval_for_expr (pc, expr);
+ }
else
- agent = gen_trace_for_expr (pc, expr);
+ agent = gen_trace_for_expr (pc, expr, trace_string);
make_cleanup_free_agent_expr (agent);
}