/* Perform an inferior function call, for GDB, the GNU debugger.
- Copyright (C) 1986-2015 Free Software Foundation, Inc.
+ Copyright (C) 1986-2017 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 "objfiles.h"
#include "gdbcmd.h"
#include "command.h"
-#include "infcall.h"
#include "dummy-frame.h"
#include "ada-lang.h"
#include "gdbthread.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. */
Unfortunately, on certain older platforms, the debug info doesn't
indicate reliably how each function was defined. A function type's
- TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
- defined in prototype style. When calling a function whose
- TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
- decide what to do.
+ TYPE_PROTOTYPED flag may be clear, even if the function was defined
+ in prototype style. When calling a function whose TYPE_PROTOTYPED
+ flag is clear, GDB consults this flag to decide what to do.
For modern targets, it is proper to assume that, if the prototype
flag is clear, that can be trusted: `float' arguments should be
switch (TYPE_CODE (type))
{
case TYPE_CODE_REF:
+ case TYPE_CODE_RVALUE_REF:
{
struct value *new_value;
- if (TYPE_CODE (arg_type) == TYPE_CODE_REF)
+ if (TYPE_IS_REFERENCE (arg_type))
return value_cast_pointers (type, arg, 0);
/* Cast the value to the reference's target type, and then
if the value was not previously in memory - in some cases
we should clearly be allowing this, but how? */
new_value = value_cast (TYPE_TARGET_TYPE (type), arg);
- new_value = value_ref (new_value);
+ new_value = value_ref (new_value, TYPE_CODE (type));
return new_value;
}
case TYPE_CODE_INT:
regcache);
}
+/* See infcall.h. */
+
+void
+error_call_unknown_return_type (const char *func_name)
+{
+ if (func_name != NULL)
+ error (_("'%s' has unknown return type; "
+ "cast the call to its declared return type"),
+ func_name);
+ else
+ error (_("function has unknown return type; "
+ "cast the call to its declared return type"));
+}
+
/* Fetch the name of the function at FUNADDR.
This is used in printing an error message for call_function_by_hand.
BUF is used to print FUNADDR in hex if the function name cannot be
}
}
+/* 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;
+
+ /* The top level that started the infcall (and is synchronously
+ waiting for it to end). */
+ struct ui *waiting_ui;
+};
+
+static int call_thread_fsm_should_stop (struct thread_fsm *self,
+ struct thread_info *thread);
+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 ui *waiting_ui, struct interp *cmd_interp,
+ 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, cmd_interp);
+
+ 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;
+
+ sm->waiting_ui = waiting_ui;
+
+ return sm;
+}
+
+/* Implementation of should_stop method for infcalls. */
+
+static int
+call_thread_fsm_should_stop (struct thread_fsm *self,
+ struct thread_info *thread)
+{
+ 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. */
+ scoped_restore save_ui = make_scoped_restore (¤t_ui, f->waiting_ui);
+ target_terminal::ours ();
+ f->waiting_ui->prompt_state = PROMPT_NEEDED;
+ }
+
+ 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)
{
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;
+ enum prompt_state saved_prompt_state = current_ui->prompt_state;
int was_running = call_thread->state == THREAD_RUNNING;
- int saved_interpreter_async = interpreter_async;
+ int saved_ui_async = current_ui->async;
/* Infcalls run synchronously, in the foreground. */
- sync_execution = 1;
+ current_ui->prompt_state = PROMPT_BLOCKED;
/* So that we don't print the prompt prematurely in
fetch_inferior_event. */
- interpreter_async = 0;
+ current_ui->async = 0;
+
+ delete_file_handler (current_ui->input_fd);
call_thread->control.in_infcall = 1;
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 to print return value, please... */
}
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
+ /* If GDB has the prompt blocked before, then ensure that it remains
+ so. normal_stop calls async_enable_stdin, so reset the prompt
+ state 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;
+ current_ui->prompt_state = saved_prompt_state;
+ if (current_ui->prompt_state == PROMPT_BLOCKED)
+ delete_file_handler (current_ui->input_fd);
+ else
+ ui_register_input_event_handler (current_ui);
+ current_ui->async = saved_ui_async;
/* At this point the current thread may have changed. Refresh
CALL_THREAD as it could be invalid if its thread has exited. */
/* 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);
-}
-
-/* Data for dummy_frame_context_saver. Structure can be freed only
- after both dummy_frame_context_saver_dtor and
- dummy_frame_context_saver_drop have been called for it. */
-
-struct dummy_frame_context_saver
-{
- /* Inferior registers fetched before associated dummy_frame got freed
- and before any other destructors of associated dummy_frame got called.
- It is initialized to NULL. */
- struct regcache *retbuf;
-
- /* It is 1 if this dummy_frame_context_saver_drop has been already
- called. */
- int drop_done;
-};
-
-/* Free struct dummy_frame_context_saver. */
-
-static void
-dummy_frame_context_saver_free (struct dummy_frame_context_saver *saver)
-{
- regcache_xfree (saver->retbuf);
- xfree (saver);
-}
-
-/* Destructor for associated dummy_frame. */
-
-static void
-dummy_frame_context_saver_dtor (void *data_voidp, int registers_valid)
-{
- struct dummy_frame_context_saver *data = data_voidp;
-
- gdb_assert (data->retbuf == NULL);
-
- if (data->drop_done)
- dummy_frame_context_saver_free (data);
- else if (registers_valid)
- data->retbuf = regcache_dup (get_current_regcache ());
-}
-
-/* Caller is no longer interested in this
- struct dummy_frame_context_saver. After its associated dummy_frame
- gets freed struct dummy_frame_context_saver can be also freed. */
-
-void
-dummy_frame_context_saver_drop (struct dummy_frame_context_saver *saver)
-{
- saver->drop_done = 1;
-
- if (!find_dummy_frame_dtor (dummy_frame_context_saver_dtor, saver))
- dummy_frame_context_saver_free (saver);
-}
-
-/* Stub dummy_frame_context_saver_drop compatible with make_cleanup. */
-
-void
-dummy_frame_context_saver_cleanup (void *data)
-{
- struct dummy_frame_context_saver *saver = data;
-
- dummy_frame_context_saver_drop (saver);
-}
-
-/* Fetch RETBUF field of possibly opaque DTOR_DATA.
- RETBUF must not be NULL. */
-
-struct regcache *
-dummy_frame_context_saver_get_regs (struct dummy_frame_context_saver *saver)
-{
- gdb_assert (saver->retbuf != NULL);
- return saver->retbuf;
-}
-
-/* Register provider of inferior registers at the time DUMMY_ID frame of
- PTID gets freed (before inferior registers get restored to those
- before dummy_frame). */
-
-struct dummy_frame_context_saver *
-dummy_frame_context_saver_setup (struct frame_id dummy_id, ptid_t ptid)
+call_function_by_hand (struct value *function,
+ type *default_return_type,
+ int nargs, struct value **args)
{
- struct dummy_frame_context_saver *saver =
- XNEW (struct dummy_frame_context_saver);
-
- saver->retbuf = NULL;
- saver->drop_done = 0;
- register_dummy_frame_dtor (dummy_id, inferior_ptid,
- dummy_frame_context_saver_dtor, saver);
- return saver;
+ return call_function_by_hand_dummy (function, default_return_type,
+ nargs, args, NULL, NULL);
}
/* All this stuff with a dummy frame may seem unnecessarily complicated
struct value *
call_function_by_hand_dummy (struct value *function,
+ type *default_return_type,
int nargs, struct value **args,
dummy_frame_dtor_ftype *dummy_dtor,
void *dummy_dtor_data)
struct gdb_exception e;
char name_buf[RAW_FUNCTION_ADDRESS_SIZE];
int stack_temporaries = thread_stack_temporaries_enabled_p (inferior_ptid);
- struct dummy_frame_context_saver *context_saver;
- struct cleanup *context_saver_cleanup;
if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
}
funaddr = find_function_addr (function, &values_type);
- if (!values_type)
- values_type = builtin_type (gdbarch)->builtin_int;
+ if (values_type == NULL)
+ values_type = default_return_type;
+ if (values_type == NULL)
+ {
+ const char *name = get_function_name (funaddr,
+ name_buf, sizeof (name_buf));
+ error (_("'%s' has unknown return type; "
+ "cast the call to its declared return type"),
+ name);
+ }
values_type = check_typedef (values_type);
prototyped. Can we respect TYPE_VARARGS? Probably not. */
if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
prototyped = 1;
+ if (TYPE_TARGET_TYPE (ftype) == NULL && TYPE_NFIELDS (ftype) == 0
+ && default_return_type != NULL)
+ {
+ /* Calling a no-debug function with the return type
+ explicitly cast. Assume the function is prototyped,
+ with a prototype matching the types of the arguments.
+ E.g., with:
+ float mult (float v1, float v2) { return v1 * v2; }
+ This:
+ (gdb) p (float) mult (2.0f, 3.0f)
+ Is a simpler alternative to:
+ (gdb) p ((float (*) (float, float)) mult) (2.0f, 3.0f)
+ */
+ prototyped = 1;
+ }
else if (i < TYPE_NFIELDS (ftype))
prototyped = TYPE_PROTOTYPED (ftype);
else
inferior. That way it breaks when it returns. */
{
- struct breakpoint *bpt, *longjmp_b;
- struct symtab_and_line sal;
-
- init_sal (&sal); /* initialize to zeroes */
+ symtab_and_line sal;
sal.pspace = current_program_space;
sal.pc = bp_addr;
sal.section = find_pc_overlay (sal.pc);
+
/* Sanity. The exact same SP value is returned by
PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
dummy_id to form the frame ID's stack address. */
- bpt = set_momentary_breakpoint (gdbarch, sal, dummy_id, bp_call_dummy);
+ breakpoint *bpt = set_momentary_breakpoint (gdbarch, sal,
+ dummy_id, bp_call_dummy);
/* set_momentary_breakpoint invalidates FRAME. */
frame = NULL;
bpt->disposition = disp_del;
gdb_assert (bpt->related_breakpoint == bpt);
- longjmp_b = set_longjmp_breakpoint_for_call_dummy ();
+ breakpoint *longjmp_b = set_longjmp_breakpoint_for_call_dummy ();
if (longjmp_b)
{
/* Link BPT into the chain of LONGJMP_B. */
register_dummy_frame_dtor (dummy_id, inferior_ptid,
dummy_dtor, dummy_dtor_data);
- /* dummy_frame_context_saver_setup must be called last so that its
- saving of inferior registers gets called first (before possible
- DUMMY_DTOR destructor). */
- context_saver = dummy_frame_context_saver_setup (dummy_id, inferior_ptid);
- context_saver_cleanup = make_cleanup (dummy_frame_context_saver_cleanup,
- context_saver);
-
/* 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 (current_ui, command_interp (),
+ 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, tp);
+ thread_fsm_delete (tp->thread_fsm);
+ tp->thread_fsm = saved_sm;
+
+ maybe_remove_breakpoints ();
- observer_notify_inferior_call_post (call_thread_ptid, funaddr);
+ 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)
{
/* Make a copy as NAME may be in an objfile freed by dummy_frame_pop. */
char *name = xstrdup (get_function_name (funaddr,
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 value *retval = NULL;
-
- /* Inferior call is successful. Restore the inferior status.
- At this stage, leave the RETBUF alone. */
- restore_infcall_control_state (inf_status);
-
- if (TYPE_CODE (values_type) == TYPE_CODE_VOID)
- retval = allocate_value (values_type);
- else if (struct_return || hidden_first_param_p)
- {
- if (stack_temporaries)
- {
- retval = value_from_contents_and_address (values_type, NULL,
- struct_addr);
- push_thread_stack_temporary (inferior_ptid, retval);
- }
- else
- {
- retval = allocate_value (values_type);
- read_value_memory (retval, 0, 1, struct_addr,
- value_contents_raw (retval),
- TYPE_LENGTH (values_type));
- }
- }
- else
- {
- retval = allocate_value (values_type);
- gdbarch_return_value (gdbarch, function, values_type,
- dummy_frame_context_saver_get_regs (context_saver),
- value_contents_raw (retval), NULL);
- if (stack_temporaries && class_or_union_p (values_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, struct_addr);
- push_thread_stack_temporary (inferior_ptid, retval);
- }
- }
-
- do_cleanups (context_saver_cleanup);
-
- gdb_assert (retval);
- return retval;
- }
+ /* The above code errors out, so ... */
+ gdb_assert_not_reached ("... should not be here");
}
-\f
-
-/* Provide a prototype to silence -Wmissing-prototypes. */
-void _initialize_infcall (void);
void
_initialize_infcall (void)
projects / deliverable / binutils-gdb.git / blobdiff