/* Perform an inferior function call, for GDB, the GNU debugger.
- Copyright (C) 1986-2013 Free Software Foundation, Inc.
+ Copyright (C) 1986-2016 Free Software Foundation, Inc.
This file is part of GDB.
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
+#include "infcall.h"
#include "breakpoint.h"
#include "tracepoint.h"
#include "target.h"
#include "regcache.h"
#include "inferior.h"
-#include "gdb_assert.h"
+#include "infrun.h"
#include "block.h"
#include "gdbcore.h"
#include "language.h"
#include "objfiles.h"
#include "gdbcmd.h"
#include "command.h"
-#include <string.h>
-#include "infcall.h"
#include "dummy-frame.h"
#include "ada-lang.h"
#include "gdbthread.h"
-#include "exceptions.h"
+#include "event-top.h"
+#include "observer.h"
+#include "top.h"
+#include "interps.h"
+#include "thread-fsm.h"
/* If we can't find a function's name from its address,
we print this instead. */
struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr);
if (msymbol.minsym)
- return SYMBOL_PRINT_NAME (msymbol.minsym);
+ return MSYMBOL_PRINT_NAME (msymbol.minsym);
}
{
}
}
+/* All the meta data necessary to extract the call's return value. */
+
+struct call_return_meta_info
+{
+ /* The caller frame's architecture. */
+ struct gdbarch *gdbarch;
+
+ /* The called function. */
+ struct value *function;
+
+ /* The return value's type. */
+ struct type *value_type;
+
+ /* Are we returning a value using a structure return or a normal
+ value return? */
+ int struct_return_p;
+
+ /* If using a structure return, this is the structure's address. */
+ CORE_ADDR struct_addr;
+
+ /* Whether stack temporaries are enabled. */
+ int stack_temporaries_enabled;
+};
+
+/* Extract the called function's return value. */
+
+static struct value *
+get_call_return_value (struct call_return_meta_info *ri)
+{
+ struct value *retval = NULL;
+ int stack_temporaries = thread_stack_temporaries_enabled_p (inferior_ptid);
+
+ if (TYPE_CODE (ri->value_type) == TYPE_CODE_VOID)
+ retval = allocate_value (ri->value_type);
+ else if (ri->struct_return_p)
+ {
+ if (stack_temporaries)
+ {
+ retval = value_from_contents_and_address (ri->value_type, NULL,
+ ri->struct_addr);
+ push_thread_stack_temporary (inferior_ptid, retval);
+ }
+ else
+ {
+ retval = allocate_value (ri->value_type);
+ read_value_memory (retval, 0, 1, ri->struct_addr,
+ value_contents_raw (retval),
+ TYPE_LENGTH (ri->value_type));
+ }
+ }
+ else
+ {
+ retval = allocate_value (ri->value_type);
+ gdbarch_return_value (ri->gdbarch, ri->function, ri->value_type,
+ get_current_regcache (),
+ value_contents_raw (retval), NULL);
+ if (stack_temporaries && class_or_union_p (ri->value_type))
+ {
+ /* Values of class type returned in registers are copied onto
+ the stack and their lval_type set to lval_memory. This is
+ required because further evaluation of the expression
+ could potentially invoke methods on the return value
+ requiring GDB to evaluate the "this" pointer. To evaluate
+ the this pointer, GDB needs the memory address of the
+ value. */
+ value_force_lval (retval, ri->struct_addr);
+ push_thread_stack_temporary (inferior_ptid, retval);
+ }
+ }
+
+ gdb_assert (retval != NULL);
+ return retval;
+}
+
+/* Data for the FSM that manages an infcall. It's main job is to
+ record the called function's return value. */
+
+struct call_thread_fsm
+{
+ /* The base class. */
+ struct thread_fsm thread_fsm;
+
+ /* All the info necessary to be able to extract the return
+ value. */
+ struct call_return_meta_info return_meta_info;
+
+ /* The called function's return value. This is extracted from the
+ target before the dummy frame is popped. */
+ struct value *return_value;
+};
+
+static int call_thread_fsm_should_stop (struct thread_fsm *self);
+static int call_thread_fsm_should_notify_stop (struct thread_fsm *self);
+
+/* call_thread_fsm's vtable. */
+
+static struct thread_fsm_ops call_thread_fsm_ops =
+{
+ NULL, /*dtor */
+ NULL, /* clean_up */
+ call_thread_fsm_should_stop,
+ NULL, /* return_value */
+ NULL, /* async_reply_reason*/
+ call_thread_fsm_should_notify_stop,
+};
+
+/* Allocate a new call_thread_fsm object. */
+
+static struct call_thread_fsm *
+new_call_thread_fsm (struct gdbarch *gdbarch, struct value *function,
+ struct type *value_type,
+ int struct_return_p, CORE_ADDR struct_addr)
+{
+ struct call_thread_fsm *sm;
+
+ sm = XCNEW (struct call_thread_fsm);
+ thread_fsm_ctor (&sm->thread_fsm, &call_thread_fsm_ops);
+
+ sm->return_meta_info.gdbarch = gdbarch;
+ sm->return_meta_info.function = function;
+ sm->return_meta_info.value_type = value_type;
+ sm->return_meta_info.struct_return_p = struct_return_p;
+ sm->return_meta_info.struct_addr = struct_addr;
+
+ return sm;
+}
+
+/* Implementation of should_stop method for infcalls. */
+
+static int
+call_thread_fsm_should_stop (struct thread_fsm *self)
+{
+ struct call_thread_fsm *f = (struct call_thread_fsm *) self;
+
+ if (stop_stack_dummy == STOP_STACK_DUMMY)
+ {
+ /* Done. */
+ thread_fsm_set_finished (self);
+
+ /* Stash the return value before the dummy frame is popped and
+ registers are restored to what they were before the
+ call.. */
+ f->return_value = get_call_return_value (&f->return_meta_info);
+
+ /* Break out of wait_sync_command_done. */
+ async_enable_stdin ();
+ }
+
+ return 1;
+}
+
+/* Implementation of should_notify_stop method for infcalls. */
+
+static int
+call_thread_fsm_should_notify_stop (struct thread_fsm *self)
+{
+ if (thread_fsm_finished_p (self))
+ {
+ /* Infcall succeeded. Be silent and proceed with evaluating the
+ expression. */
+ return 0;
+ }
+
+ /* Something wrong happened. E.g., an unexpected breakpoint
+ triggered, or a signal was intercepted. Notify the stop. */
+ return 1;
+}
+
/* Subroutine of call_function_by_hand to simplify it.
Start up the inferior and wait for it to stop.
Return the exception if there's an error, or an exception with
thrown errors. The caller should rethrow if there's an error. */
static struct gdb_exception
-run_inferior_call (struct thread_info *call_thread, CORE_ADDR real_pc)
+run_inferior_call (struct call_thread_fsm *sm,
+ struct thread_info *call_thread, CORE_ADDR real_pc)
{
- volatile struct gdb_exception e;
+ struct gdb_exception caught_error = exception_none;
int saved_in_infcall = call_thread->control.in_infcall;
ptid_t call_thread_ptid = call_thread->ptid;
+ int saved_sync_execution = sync_execution;
+ int was_running = call_thread->state == THREAD_RUNNING;
+ int saved_interpreter_async = interpreter_async;
+
+ /* Infcalls run synchronously, in the foreground. */
+ sync_execution = 1;
+ /* So that we don't print the prompt prematurely in
+ fetch_inferior_event. */
+ interpreter_async = 0;
call_thread->control.in_infcall = 1;
- clear_proceed_status ();
+ clear_proceed_status (0);
+
+ /* Associate the FSM with the thread after clear_proceed_status
+ (otherwise it'd clear this FSM), and before anything throws, so
+ we don't leak it (and any resources it manages). */
+ call_thread->thread_fsm = &sm->thread_fsm;
disable_watchpoints_before_interactive_call_start ();
- /* We want stop_registers, please... */
+ /* We want to print return value, please... */
call_thread->control.proceed_to_finish = 1;
- TRY_CATCH (e, RETURN_MASK_ALL)
+ TRY
{
- proceed (real_pc, GDB_SIGNAL_0, 0);
+ proceed (real_pc, GDB_SIGNAL_0);
/* Inferior function calls are always synchronous, even if the
- target supports asynchronous execution. Do here what
- `proceed' itself does in sync mode. */
- if (target_can_async_p () && is_running (inferior_ptid))
- {
- wait_for_inferior ();
- normal_stop ();
- }
+ target supports asynchronous execution. */
+ wait_sync_command_done ();
}
+ CATCH (e, RETURN_MASK_ALL)
+ {
+ caught_error = e;
+ }
+ END_CATCH
+
+ /* If GDB was previously in sync execution mode, then ensure that it
+ remains so. normal_stop calls async_enable_stdin, so reset it
+ again here. In other cases, stdin will be re-enabled by
+ inferior_event_handler, when an exception is thrown. */
+ sync_execution = saved_sync_execution;
+ interpreter_async = saved_interpreter_async;
/* At this point the current thread may have changed. Refresh
CALL_THREAD as it could be invalid if its thread has exited. */
call_thread = find_thread_ptid (call_thread_ptid);
+ /* If the infcall does NOT succeed, normal_stop will have already
+ finished the thread states. However, on success, normal_stop
+ defers here, so that we can set back the thread states to what
+ they were before the call. Note that we must also finish the
+ state of new threads that might have spawned while the call was
+ running. The main cases to handle are:
+
+ - "(gdb) print foo ()", or any other command that evaluates an
+ expression at the prompt. (The thread was marked stopped before.)
+
+ - "(gdb) break foo if return_false()" or similar cases where we
+ do an infcall while handling an event (while the thread is still
+ marked running). In this example, whether the condition
+ evaluates true and thus we'll present a user-visible stop is
+ decided elsewhere. */
+ if (!was_running
+ && ptid_equal (call_thread_ptid, inferior_ptid)
+ && stop_stack_dummy == STOP_STACK_DUMMY)
+ finish_thread_state (user_visible_resume_ptid (0));
+
enable_watchpoints_after_interactive_call_stop ();
/* Call breakpoint_auto_delete on the current contents of the bpstat
If all error()s out of proceed ended up calling normal_stop
(and perhaps they should; it already does in the special case
of error out of resume()), then we wouldn't need this. */
- if (e.reason < 0)
+ if (caught_error.reason < 0)
{
if (call_thread != NULL)
breakpoint_auto_delete (call_thread->control.stop_bpstat);
if (call_thread != NULL)
call_thread->control.in_infcall = saved_in_infcall;
- return e;
+ return caught_error;
}
/* A cleanup function that calls delete_std_terminate_breakpoint. */
delete_std_terminate_breakpoint ();
}
+/* See infcall.h. */
+
+struct value *
+call_function_by_hand (struct value *function, int nargs, struct value **args)
+{
+ return call_function_by_hand_dummy (function, nargs, args, NULL, NULL);
+}
+
/* All this stuff with a dummy frame may seem unnecessarily complicated
(why not just save registers in GDB?). The purpose of pushing a dummy
frame which looks just like a real frame is so that if you call a
ARGS is modified to contain coerced values. */
struct value *
-call_function_by_hand (struct value *function, int nargs, struct value **args)
+call_function_by_hand_dummy (struct value *function,
+ int nargs, struct value **args,
+ dummy_frame_dtor_ftype *dummy_dtor,
+ void *dummy_dtor_data)
{
CORE_ADDR sp;
struct type *values_type, *target_values_type;
ptid_t call_thread_ptid;
struct gdb_exception e;
char name_buf[RAW_FUNCTION_ADDRESS_SIZE];
+ int stack_temporaries = thread_stack_temporaries_enabled_p (inferior_ptid);
if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
If the ABI specifies a "Red Zone" (see the doco) the code
below will quietly trash it. */
sp = old_sp;
+
+ /* Skip over the stack temporaries that might have been generated during
+ the evaluation of an expression. */
+ if (stack_temporaries)
+ {
+ struct value *lastval;
+
+ lastval = get_last_thread_stack_temporary (inferior_ptid);
+ if (lastval != NULL)
+ {
+ CORE_ADDR lastval_addr = value_address (lastval);
+
+ if (gdbarch_inner_than (gdbarch, 1, 2))
+ {
+ gdb_assert (sp >= lastval_addr);
+ sp = lastval_addr;
+ }
+ else
+ {
+ gdb_assert (sp <= lastval_addr);
+ sp = lastval_addr + TYPE_LENGTH (value_type (lastval));
+ }
+
+ if (gdbarch_frame_align_p (gdbarch))
+ sp = gdbarch_frame_align (gdbarch, sp);
+ }
+ }
}
funaddr = find_function_addr (function, &values_type);
if (!values_type)
values_type = builtin_type (gdbarch)->builtin_int;
- CHECK_TYPEDEF (values_type);
+ values_type = check_typedef (values_type);
/* Are we returning a value using a structure return (passing a
hidden argument pointing to storage) or a normal value return?
target_values_type = values_type;
}
+ observer_notify_inferior_call_pre (inferior_ptid, funaddr);
+
/* Determine the location of the breakpoint (and possibly other
stuff) that the called function will return to. The SPARC, for a
function returning a structure or union, needs to make space for
/* Reserve space for the return structure to be written on the
stack, if necessary. Make certain that the value is correctly
- aligned. */
+ aligned.
+
+ While evaluating expressions, we reserve space on the stack for
+ return values of class type even if the language ABI and the target
+ ABI do not require that the return value be passed as a hidden first
+ argument. This is because we want to store the return value as an
+ on-stack temporary while the expression is being evaluated. This
+ enables us to have chained function calls in expressions.
+
+ Keeping the return values as on-stack temporaries while the expression
+ is being evaluated is OK because the thread is stopped until the
+ expression is completely evaluated. */
- if (struct_return || hidden_first_param_p)
+ if (struct_return || hidden_first_param_p
+ || (stack_temporaries && class_or_union_p (values_type)))
{
if (gdbarch_inner_than (gdbarch, 1, 2))
{
struct value **new_args;
/* Add the new argument to the front of the argument list. */
- new_args = xmalloc (sizeof (struct value *) * (nargs + 1));
+ new_args = XNEWVEC (struct value *, nargs + 1);
new_args[0] = value_from_pointer (lookup_pointer_type (values_type),
struct_addr);
memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs);
if (unwind_on_terminating_exception_p)
set_std_terminate_breakpoint ();
- /* Everything's ready, push all the info needed to restore the
- caller (and identify the dummy-frame) onto the dummy-frame
- stack. */
- dummy_frame_push (caller_state, &dummy_id);
-
/* Discard both inf_status and caller_state cleanups.
From this point on we explicitly restore the associated state
or discard it. */
discard_cleanups (inf_status_cleanup);
+ /* Everything's ready, push all the info needed to restore the
+ caller (and identify the dummy-frame) onto the dummy-frame
+ stack. */
+ dummy_frame_push (caller_state, &dummy_id, inferior_ptid);
+ if (dummy_dtor != NULL)
+ register_dummy_frame_dtor (dummy_id, inferior_ptid,
+ dummy_dtor, dummy_dtor_data);
+
/* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
terminate_bp_cleanup = make_cleanup (cleanup_delete_std_terminate_breakpoint,
NULL);
in a block so that it's only in scope during the time it's valid. */
{
struct thread_info *tp = inferior_thread ();
+ struct thread_fsm *saved_sm;
+ struct call_thread_fsm *sm;
+
+ /* Save the current FSM. We'll override it. */
+ saved_sm = tp->thread_fsm;
+ tp->thread_fsm = NULL;
/* Save this thread's ptid, we need it later but the thread
may have exited. */
/* Run the inferior until it stops. */
- e = run_inferior_call (tp, real_pc);
+ /* Create the FSM used to manage the infcall. It tells infrun to
+ not report the stop to the user, and captures the return value
+ before the dummy frame is popped. run_inferior_call registers
+ it with the thread ASAP. */
+ sm = new_call_thread_fsm (gdbarch, function,
+ values_type,
+ struct_return || hidden_first_param_p,
+ struct_addr);
+
+ e = run_inferior_call (sm, tp, real_pc);
+
+ observer_notify_inferior_call_post (call_thread_ptid, funaddr);
+
+ tp = find_thread_ptid (call_thread_ptid);
+ if (tp != NULL)
+ {
+ /* The FSM should still be the same. */
+ gdb_assert (tp->thread_fsm == &sm->thread_fsm);
+
+ if (thread_fsm_finished_p (tp->thread_fsm))
+ {
+ struct value *retval;
+
+ /* The inferior call is successful. Pop the dummy frame,
+ which runs its destructors and restores the inferior's
+ suspend state, and restore the inferior control
+ state. */
+ dummy_frame_pop (dummy_id, call_thread_ptid);
+ restore_infcall_control_state (inf_status);
+
+ /* Get the return value. */
+ retval = sm->return_value;
+
+ /* Clean up / destroy the call FSM, and restore the
+ original one. */
+ thread_fsm_clean_up (tp->thread_fsm);
+ thread_fsm_delete (tp->thread_fsm);
+ tp->thread_fsm = saved_sm;
+
+ maybe_remove_breakpoints ();
+
+ do_cleanups (terminate_bp_cleanup);
+ gdb_assert (retval != NULL);
+ return retval;
+ }
+
+ /* Didn't complete. Restore previous state machine, and
+ handle the error. */
+ tp->thread_fsm = saved_sm;
+ }
}
/* Rethrow an error if we got one trying to run the inferior. */
name);
}
- if (stopped_by_random_signal || stop_stack_dummy != STOP_STACK_DUMMY)
{
- const char *name = get_function_name (funaddr,
- name_buf, sizeof (name_buf));
+ /* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */
+ char *name = xstrdup (get_function_name (funaddr,
+ name_buf, sizeof (name_buf)));
+ make_cleanup (xfree, name);
+
if (stopped_by_random_signal)
{
/* We must get back to the frame we were before the
dummy call. */
- dummy_frame_pop (dummy_id);
+ dummy_frame_pop (dummy_id, call_thread_ptid);
/* We also need to restore inferior status to that before the
dummy call. */
{
/* We must get back to the frame we were before the dummy
call. */
- dummy_frame_pop (dummy_id);
+ dummy_frame_pop (dummy_id, call_thread_ptid);
/* We also need to restore inferior status to that before
the dummy call. */
name);
}
- /* The above code errors out, so ... */
- internal_error (__FILE__, __LINE__, _("... should not be here"));
}
- do_cleanups (terminate_bp_cleanup);
-
- /* If we get here the called FUNCTION ran to completion,
- and the dummy frame has already been popped. */
-
- {
- struct address_space *aspace = get_regcache_aspace (stop_registers);
- struct regcache *retbuf = regcache_xmalloc (gdbarch, aspace);
- struct cleanup *retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
- struct value *retval = NULL;
-
- regcache_cpy_no_passthrough (retbuf, stop_registers);
-
- /* Inferior call is successful. Restore the inferior status.
- At this stage, leave the RETBUF alone. */
- restore_infcall_control_state (inf_status);
-
- /* Figure out the value returned by the function. */
- retval = allocate_value (values_type);
-
- if (hidden_first_param_p)
- read_value_memory (retval, 0, 1, struct_addr,
- value_contents_raw (retval),
- TYPE_LENGTH (values_type));
- else if (TYPE_CODE (target_values_type) != TYPE_CODE_VOID)
- {
- /* If the function returns void, don't bother fetching the
- return value. */
- switch (gdbarch_return_value (gdbarch, function, target_values_type,
- NULL, NULL, NULL))
- {
- case RETURN_VALUE_REGISTER_CONVENTION:
- case RETURN_VALUE_ABI_RETURNS_ADDRESS:
- case RETURN_VALUE_ABI_PRESERVES_ADDRESS:
- gdbarch_return_value (gdbarch, function, values_type,
- retbuf, value_contents_raw (retval), NULL);
- break;
- case RETURN_VALUE_STRUCT_CONVENTION:
- read_value_memory (retval, 0, 1, struct_addr,
- value_contents_raw (retval),
- TYPE_LENGTH (values_type));
- break;
- }
- }
-
- do_cleanups (retbuf_cleanup);
-
- gdb_assert (retval);
- return retval;
- }
+ /* The above code errors out, so ... */
+ gdb_assert_not_reached ("... should not be here");
}
\f
projects / deliverable / binutils-gdb.git / blobdiff