/* Perform an inferior function call, for GDB, the GNU debugger.
- Copyright (C) 1986-2012 Free Software Foundation, Inc.
+ Copyright (C) 1986-2019 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 "gdb_string.h"
-#include "infcall.h"
#include "dummy-frame.h"
#include "ada-lang.h"
+#include "f-lang.h"
#include "gdbthread.h"
-#include "exceptions.h"
+#include "event-top.h"
+#include "observable.h"
+#include "top.h"
+#include "interps.h"
+#include "thread-fsm.h"
+#include <algorithm>
+#include "gdbsupport/scope-exit.h"
/* If we can't find a function's name from its address,
we print this instead. */
asynchronous inferior function call implementation, and that in
turn means restructuring the code so that it is event driven. */
+static bool may_call_functions_p = true;
+static void
+show_may_call_functions_p (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c,
+ const char *value)
+{
+ fprintf_filtered (file,
+ _("Permission to call functions in the program is %s.\n"),
+ value);
+}
+
/* How you should pass arguments to a function depends on whether it
was defined in K&R style or prototype style. If you define a
function using the K&R syntax that takes a `float' argument, then
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
trust the debug information; the user can override this behavior
with "set coerce-float-to-double 0". */
-static int coerce_float_to_double_p = 1;
+static bool coerce_float_to_double_p = true;
static void
show_coerce_float_to_double_p (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
The default is to stop in the frame where the signal was received. */
-static int unwind_on_signal_p = 0;
+static bool unwind_on_signal_p = false;
static void
show_unwind_on_signal_p (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
The default is to unwind the frame if a std::terminate call is
made. */
-static int unwind_on_terminating_exception_p = 1;
+static bool unwind_on_terminating_exception_p = true;
static void
show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
}
/* Perform the standard coercions that are specified
- for arguments to be passed to C or Ada functions.
+ for arguments to be passed to C, Ada or Fortran functions.
If PARAM_TYPE is non-NULL, it is the expected parameter type.
IS_PROTOTYPED is non-zero if the function declaration is prototyped.
struct type *type
= param_type ? check_typedef (param_type) : arg_type;
- /* Perform any Ada-specific coercion first. */
+ /* Perform any Ada- and Fortran-specific coercion first. */
if (current_language->la_language == language_ada)
arg = ada_convert_actual (arg, type);
+ else if (current_language->la_language == language_fortran)
+ type = fortran_preserve_arg_pointer (arg, type);
/* Force the value to the target if we will need its address. At
this point, we could allocate arguments on the stack instead of
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)
- return value_cast_pointers (type, arg);
+ if (TYPE_IS_REFERENCE (arg_type))
+ return value_cast_pointers (type, arg, 0);
/* Cast the value to the reference's target type, and then
convert it back to a reference. This will issue an error
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:
case TYPE_CODE_SET:
case TYPE_CODE_RANGE:
case TYPE_CODE_STRING:
- case TYPE_CODE_BITSTRING:
case TYPE_CODE_ERROR:
case TYPE_CODE_MEMBERPTR:
case TYPE_CODE_METHODPTR:
return value_cast (type, arg);
}
-/* Return the return type of a function with its first instruction exactly at
- the PC address. Return NULL otherwise. */
-
-static struct type *
-find_function_return_type (CORE_ADDR pc)
-{
- struct symbol *sym = find_pc_function (pc);
-
- if (sym != NULL && BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) == pc
- && SYMBOL_TYPE (sym) != NULL)
- return TYPE_TARGET_TYPE (SYMBOL_TYPE (sym));
-
- return NULL;
-}
-
-/* Determine a function's address and its return type from its value.
- Calls error() if the function is not valid for calling. */
+/* See infcall.h. */
CORE_ADDR
-find_function_addr (struct value *function, struct type **retval_type)
+find_function_addr (struct value *function,
+ struct type **retval_type,
+ struct type **function_type)
{
struct type *ftype = check_typedef (value_type (function));
struct gdbarch *gdbarch = get_type_arch (ftype);
if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
|| TYPE_CODE (ftype) == TYPE_CODE_METHOD)
funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
- ¤t_target);
+ current_top_target ());
}
if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
|| TYPE_CODE (ftype) == TYPE_CODE_METHOD)
{
- value_type = TYPE_TARGET_TYPE (ftype);
-
if (TYPE_GNU_IFUNC (ftype))
{
- funaddr = gnu_ifunc_resolve_addr (gdbarch, funaddr);
+ CORE_ADDR resolver_addr = funaddr;
+
+ /* Resolve the ifunc. Note this may call the resolver
+ function in the inferior. */
+ funaddr = gnu_ifunc_resolve_addr (gdbarch, resolver_addr);
- /* Skip querying the function symbol if no RETVAL_TYPE has been
- asked for. */
- if (retval_type)
- value_type = find_function_return_type (funaddr);
+ /* Skip querying the function symbol if no RETVAL_TYPE or
+ FUNCTION_TYPE have been asked for. */
+ if (retval_type != NULL || function_type != NULL)
+ {
+ type *target_ftype = find_function_type (funaddr);
+ /* If we don't have debug info for the target function,
+ see if we can instead extract the target function's
+ type from the type that the resolver returns. */
+ if (target_ftype == NULL)
+ target_ftype = find_gnu_ifunc_target_type (resolver_addr);
+ if (target_ftype != NULL)
+ {
+ value_type = TYPE_TARGET_TYPE (check_typedef (target_ftype));
+ ftype = target_ftype;
+ }
+ }
}
+ else
+ value_type = TYPE_TARGET_TYPE (ftype);
}
else if (TYPE_CODE (ftype) == TYPE_CODE_INT)
{
funaddr = value_as_address (value_addr (function));
nfunaddr = funaddr;
- funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
- ¤t_target);
+ funaddr
+ = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
+ current_top_target ());
if (funaddr != nfunaddr)
found_descriptor = 1;
}
if (retval_type != NULL)
*retval_type = value_type;
+ if (function_type != NULL)
+ *function_type = ftype;
return funaddr + gdbarch_deprecated_function_start_offset (gdbarch);
}
static CORE_ADDR
push_dummy_code (struct gdbarch *gdbarch,
CORE_ADDR sp, CORE_ADDR funaddr,
- struct value **args, int nargs,
+ gdb::array_view<value *> args,
struct type *value_type,
CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
struct regcache *regcache)
gdb_assert (gdbarch_push_dummy_code_p (gdbarch));
return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
- args, nargs, value_type, real_pc, bp_addr,
+ args.data (), args.size (),
+ value_type, real_pc, bp_addr,
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
{
/* Try the minimal symbols. */
- struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
+ struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr);
- if (msymbol)
- return SYMBOL_PRINT_NAME (msymbol);
+ if (msymbol.minsym)
+ return MSYMBOL_PRINT_NAME (msymbol.minsym);
}
{
- char *tmp = xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT),
- hex_string (funaddr));
+ std::string tmp = string_printf (_(RAW_FUNCTION_ADDRESS_FORMAT),
+ hex_string (funaddr));
- gdb_assert (strlen (tmp) + 1 <= buf_size);
- strcpy (buf, tmp);
- xfree (tmp);
- return buf;
+ gdb_assert (tmp.length () + 1 <= buf_size);
+ return strcpy (buf, tmp.c_str ());
}
}
+/* 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;
+};
+
+/* Extract the called function's return value. */
+
+static struct value *
+get_call_return_value (struct call_return_meta_info *ri)
+{
+ struct value *retval = NULL;
+ thread_info *thr = inferior_thread ();
+ bool stack_temporaries = thread_stack_temporaries_enabled_p (thr);
+
+ 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 (thr, 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 (thr, 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 : public 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 = nullptr;
+
+ /* The top level that started the infcall (and is synchronously
+ waiting for it to end). */
+ struct ui *waiting_ui;
+
+ 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);
+
+ bool should_stop (struct thread_info *thread) override;
+
+ bool should_notify_stop () override;
+};
+
+/* Allocate a new call_thread_fsm object. */
+
+call_thread_fsm::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)
+ : thread_fsm (cmd_interp),
+ waiting_ui (waiting_ui)
+{
+ return_meta_info.gdbarch = gdbarch;
+ return_meta_info.function = function;
+ return_meta_info.value_type = value_type;
+ return_meta_info.struct_return_p = struct_return_p;
+ return_meta_info.struct_addr = struct_addr;
+}
+
+/* Implementation of should_stop method for infcalls. */
+
+bool
+call_thread_fsm::should_stop (struct thread_info *thread)
+{
+ if (stop_stack_dummy == STOP_STACK_DUMMY)
+ {
+ /* Done. */
+ set_finished ();
+
+ /* Stash the return value before the dummy frame is popped and
+ registers are restored to what they were before the
+ call.. */
+ return_value = get_call_return_value (&return_meta_info);
+
+ /* Break out of wait_sync_command_done. */
+ scoped_restore save_ui = make_scoped_restore (¤t_ui, waiting_ui);
+ target_terminal::ours ();
+ waiting_ui->prompt_state = PROMPT_NEEDED;
+ }
+
+ return true;
+}
+
+/* Implementation of should_notify_stop method for infcalls. */
+
+bool
+call_thread_fsm::should_notify_stop ()
+{
+ if (finished_p ())
+ {
+ /* Infcall succeeded. Be silent and proceed with evaluating the
+ expression. */
+ return false;
+ }
+
+ /* Something wrong happened. E.g., an unexpected breakpoint
+ triggered, or a signal was intercepted. Notify the stop. */
+ return true;
+}
+
/* 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;
int saved_in_infcall = call_thread->control.in_infcall;
ptid_t call_thread_ptid = call_thread->ptid;
+ enum prompt_state saved_prompt_state = current_ui->prompt_state;
+ int was_running = call_thread->state == THREAD_RUNNING;
+ int saved_ui_async = current_ui->async;
+
+ /* Infcalls run synchronously, in the foreground. */
+ current_ui->prompt_state = PROMPT_BLOCKED;
+ /* So that we don't print the prompt prematurely in
+ fetch_inferior_event. */
+ current_ui->async = 0;
+
+ delete_file_handler (current_ui->input_fd);
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;
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, TARGET_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 (gdb_exception &e)
+ {
+ caught_error = std::move (e);
}
- /* 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 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. */
+ 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;
+
+ /* 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
+ && 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 ();
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)
+ if (call_thread->state != THREAD_EXITED)
breakpoint_auto_delete (call_thread->control.stop_bpstat);
}
- if (call_thread != NULL)
- call_thread->control.in_infcall = saved_in_infcall;
+ call_thread->control.in_infcall = saved_in_infcall;
- return e;
+ return caught_error;
}
-/* A cleanup function that calls delete_std_terminate_breakpoint. */
-static void
-cleanup_delete_std_terminate_breakpoint (void *ignore)
+/* See infcall.h. */
+
+struct value *
+call_function_by_hand (struct value *function,
+ type *default_return_type,
+ gdb::array_view<value *> args)
{
- delete_std_terminate_breakpoint ();
+ return call_function_by_hand_dummy (function, default_return_type,
+ args, NULL, NULL);
}
/* All this stuff with a dummy frame may seem unnecessarily complicated
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,
+ type *default_return_type,
+ gdb::array_view<value *> args,
+ dummy_frame_dtor_ftype *dummy_dtor,
+ void *dummy_dtor_data)
{
CORE_ADDR sp;
- struct type *values_type, *target_values_type;
- unsigned char struct_return = 0, lang_struct_return = 0;
+ struct type *target_values_type;
+ function_call_return_method return_method = return_method_normal;
CORE_ADDR struct_addr = 0;
- struct infcall_control_state *inf_status;
- struct cleanup *inf_status_cleanup;
- struct infcall_suspend_state *caller_state;
- CORE_ADDR funaddr;
CORE_ADDR real_pc;
- struct type *ftype = check_typedef (value_type (function));
CORE_ADDR bp_addr;
struct frame_id dummy_id;
- struct cleanup *args_cleanup;
struct frame_info *frame;
struct gdbarch *gdbarch;
- struct cleanup *terminate_bp_cleanup;
ptid_t call_thread_ptid;
struct gdb_exception e;
char name_buf[RAW_FUNCTION_ADDRESS_SIZE];
- if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
- ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
+ if (!may_call_functions_p)
+ error (_("Cannot call functions in the program: "
+ "may-call-functions is off."));
if (!target_has_execution)
noprocess ();
if (execution_direction == EXEC_REVERSE)
error (_("Cannot call functions in reverse mode."));
+ /* We're going to run the target, and inspect the thread's state
+ afterwards. Hold a strong reference so that the pointer remains
+ valid even if the thread exits. */
+ thread_info_ref call_thread
+ = thread_info_ref::new_reference (inferior_thread ());
+
+ bool stack_temporaries = thread_stack_temporaries_enabled_p (call_thread.get ());
+
frame = get_current_frame ();
gdbarch = get_frame_arch (frame);
if (!gdbarch_push_dummy_call_p (gdbarch))
error (_("This target does not support function calls."));
- /* A cleanup for the inferior status.
+ /* A holder for the inferior status.
This is only needed while we're preparing the inferior function call. */
- inf_status = save_infcall_control_state ();
- inf_status_cleanup
- = make_cleanup_restore_infcall_control_state (inf_status);
+ infcall_control_state_up inf_status (save_infcall_control_state ());
/* Save the caller's registers and other state associated with the
inferior itself so that they can be restored once the
callee returns. To allow nested calls the registers are (further
- down) pushed onto a dummy frame stack. Include a cleanup (which
- is tossed once the regcache has been pushed). */
- caller_state = save_infcall_suspend_state ();
- make_cleanup_restore_infcall_suspend_state (caller_state);
+ down) pushed onto a dummy frame stack. This unique pointer
+ is released once the regcache has been pushed). */
+ infcall_suspend_state_up caller_state (save_infcall_suspend_state ());
/* Ensure that the initial SP is correctly aligned. */
{
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 (call_thread.get ());
+ 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;
+ type *ftype;
+ type *values_type;
+ CORE_ADDR funaddr = find_function_addr (function, &values_type, &ftype);
+
+ 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);
+ }
- 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?
- There are two cases: language-mandated structure return and
- target ABI structure return. The variable STRUCT_RETURN only
- describes the latter. The language version is handled by passing
- the return location as the first parameter to the function,
- even preceding "this". This is different from the target
- ABI version, which is target-specific; for instance, on ia64
- the first argument is passed in out0 but the hidden structure
- return pointer would normally be passed in r8. */
+ /* Are we returning a value using a structure return? */
- if (language_pass_by_reference (values_type))
+ if (gdbarch_return_in_first_hidden_param_p (gdbarch, values_type))
{
- lang_struct_return = 1;
+ return_method = return_method_hidden_param;
/* Tell the target specific argument pushing routine not to
expect a value. */
}
else
{
- struct_return = using_struct_return (gdbarch, function, values_type);
+ if (using_struct_return (gdbarch, function, values_type))
+ return_method = return_method_struct;
target_values_type = values_type;
}
+ gdb::observers::inferior_call_pre.notify (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
not just the breakpoint but also an extra word containing the
size (?) of the structure being passed. */
- /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
- is no need to write that out. */
-
switch (gdbarch_call_dummy_location (gdbarch))
{
case ON_STACK:
- sp = push_dummy_code (gdbarch, sp, funaddr,
- args, nargs, target_values_type,
- &real_pc, &bp_addr, get_current_regcache ());
+ {
+ const gdb_byte *bp_bytes;
+ CORE_ADDR bp_addr_as_address;
+ int bp_size;
+
+ /* Be careful BP_ADDR is in inferior PC encoding while
+ BP_ADDR_AS_ADDRESS is a plain memory address. */
+
+ sp = push_dummy_code (gdbarch, sp, funaddr, args,
+ target_values_type, &real_pc, &bp_addr,
+ get_current_regcache ());
+
+ /* Write a legitimate instruction at the point where the infcall
+ breakpoint is going to be inserted. While this instruction
+ is never going to be executed, a user investigating the
+ memory from GDB would see this instruction instead of random
+ uninitialized bytes. We chose the breakpoint instruction
+ as it may look as the most logical one to the user and also
+ valgrind 3.7.0 needs it for proper vgdb inferior calls.
+
+ If software breakpoints are unsupported for this target we
+ leave the user visible memory content uninitialized. */
+
+ bp_addr_as_address = bp_addr;
+ bp_bytes = gdbarch_breakpoint_from_pc (gdbarch, &bp_addr_as_address,
+ &bp_size);
+ if (bp_bytes != NULL)
+ write_memory (bp_addr_as_address, bp_bytes, bp_size);
+ }
break;
case AT_ENTRY_POINT:
{
real_pc = funaddr;
dummy_addr = entry_point_address ();
+
/* A call dummy always consists of just a single breakpoint, so
- its address is the same as the address of the dummy. */
+ its address is the same as the address of the dummy.
+
+ The actual breakpoint is inserted separatly so there is no need to
+ write that out. */
bp_addr = dummy_addr;
break;
}
internal_error (__FILE__, __LINE__, _("bad switch"));
}
- if (nargs < TYPE_NFIELDS (ftype))
+ if (args.size () < TYPE_NFIELDS (ftype))
error (_("Too few arguments in function call."));
- {
- int i;
-
- for (i = nargs - 1; i >= 0; i--)
- {
- int prototyped;
- struct type *param_type;
-
- /* FIXME drow/2002-05-31: Should just always mark methods as
- prototyped. Can we respect TYPE_VARARGS? Probably not. */
- if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
+ for (int i = args.size () - 1; i >= 0; i--)
+ {
+ int prototyped;
+ struct type *param_type;
+
+ /* FIXME drow/2002-05-31: Should just always mark methods as
+ 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
- prototyped = 0;
+ }
+ else if (i < TYPE_NFIELDS (ftype))
+ prototyped = TYPE_PROTOTYPED (ftype);
+ else
+ prototyped = 0;
- if (i < TYPE_NFIELDS (ftype))
- param_type = TYPE_FIELD_TYPE (ftype, i);
- else
- param_type = NULL;
+ if (i < TYPE_NFIELDS (ftype))
+ param_type = TYPE_FIELD_TYPE (ftype, i);
+ else
+ param_type = NULL;
- args[i] = value_arg_coerce (gdbarch, args[i],
- param_type, prototyped, &sp);
+ args[i] = value_arg_coerce (gdbarch, args[i],
+ param_type, prototyped, &sp);
- if (param_type != NULL && language_pass_by_reference (param_type))
- args[i] = value_addr (args[i]);
- }
- }
+ if (param_type != NULL && language_pass_by_reference (param_type))
+ args[i] = value_addr (args[i]);
+ }
/* Reserve space for the return structure to be written on the
stack, if necessary. Make certain that the value is correctly
- aligned. */
+ aligned.
- if (struct_return || lang_struct_return)
- {
- int len = TYPE_LENGTH (values_type);
+ 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 (return_method != return_method_normal
+ || (stack_temporaries && class_or_union_p (values_type)))
+ {
if (gdbarch_inner_than (gdbarch, 1, 2))
{
/* Stack grows downward. Align STRUCT_ADDR and SP after
making space for the return value. */
- sp -= len;
+ sp -= TYPE_LENGTH (values_type);
if (gdbarch_frame_align_p (gdbarch))
sp = gdbarch_frame_align (gdbarch, sp);
struct_addr = sp;
if (gdbarch_frame_align_p (gdbarch))
sp = gdbarch_frame_align (gdbarch, sp);
struct_addr = sp;
- sp += len;
+ sp += TYPE_LENGTH (values_type);
if (gdbarch_frame_align_p (gdbarch))
sp = gdbarch_frame_align (gdbarch, sp);
}
}
- if (lang_struct_return)
+ std::vector<struct value *> new_args;
+ if (return_method == return_method_hidden_param)
{
- 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[0] = value_from_pointer (lookup_pointer_type (values_type),
- struct_addr);
- memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs);
+ new_args.reserve (args.size ());
+ new_args.push_back
+ (value_from_pointer (lookup_pointer_type (values_type), struct_addr));
+ new_args.insert (new_args.end (), args.begin (), args.end ());
args = new_args;
- nargs++;
- args_cleanup = make_cleanup (xfree, args);
}
- else
- args_cleanup = make_cleanup (null_cleanup, NULL);
/* Create the dummy stack frame. Pass in the call dummy address as,
presumably, the ABI code knows where, in the call dummy, the
return address should be pointed. */
sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (),
- bp_addr, nargs, args,
- sp, struct_return, struct_addr);
-
- do_cleanups (args_cleanup);
+ bp_addr, args.size (), args.data (),
+ sp, return_method, struct_addr);
/* Set up a frame ID for the dummy frame so we can pass it to
set_momentary_breakpoint. We need to give the breakpoint a frame
inferior. That way it breaks when it returns. */
{
- struct breakpoint *bpt;
- 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).release ();
/* set_momentary_breakpoint invalidates FRAME. */
frame = NULL;
bpt->disposition = disp_del;
+ gdb_assert (bpt->related_breakpoint == bpt);
+
+ breakpoint *longjmp_b = set_longjmp_breakpoint_for_call_dummy ();
+ if (longjmp_b)
+ {
+ /* Link BPT into the chain of LONGJMP_B. */
+ bpt->related_breakpoint = longjmp_b;
+ while (longjmp_b->related_breakpoint != bpt->related_breakpoint)
+ longjmp_b = longjmp_b->related_breakpoint;
+ longjmp_b->related_breakpoint = bpt;
+ }
}
/* Create a breakpoint in std::terminate.
/* 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);
+ dummy_frame_push (caller_state.release (), &dummy_id, call_thread.get ());
+ if (dummy_dtor != NULL)
+ register_dummy_frame_dtor (dummy_id, call_thread.get (),
+ 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);
+ SCOPE_EXIT { delete_std_terminate_breakpoint (); };
/* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
If you're looking to implement asynchronous dummy-frames, then
just below is the place to chop this function in two.. */
- /* TP is invalid after run_inferior_call returns, so enclose this
- 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 = call_thread->thread_fsm;
+ call_thread->thread_fsm = NULL;
/* Save this thread's ptid, we need it later but the thread
may have exited. */
- call_thread_ptid = tp->ptid;
+ call_thread_ptid = call_thread->ptid;
/* 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,
+ return_method != return_method_normal,
+ struct_addr);
+
+ e = run_inferior_call (sm, call_thread.get (), real_pc);
+
+ gdb::observers::inferior_call_post.notify (call_thread_ptid, funaddr);
+
+ if (call_thread->state != THREAD_EXITED)
+ {
+ /* The FSM should still be the same. */
+ gdb_assert (call_thread->thread_fsm == sm);
+
+ if (call_thread->thread_fsm->finished_p ())
+ {
+ 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.get ());
+ restore_infcall_control_state (inf_status.release ());
+
+ /* Get the return value. */
+ retval = sm->return_value;
+
+ /* Clean up / destroy the call FSM, and restore the
+ original one. */
+ call_thread->thread_fsm->clean_up (call_thread.get ());
+ delete call_thread->thread_fsm;
+ call_thread->thread_fsm = saved_sm;
+
+ maybe_remove_breakpoints ();
+
+ gdb_assert (retval != NULL);
+ return retval;
+ }
+
+ /* Didn't complete. Clean up / destroy the call FSM, and restore the
+ previous state machine, and handle the error. */
+ call_thread->thread_fsm->clean_up (call_thread.get ());
+ delete call_thread->thread_fsm;
+ call_thread->thread_fsm = saved_sm;
+ }
}
/* Rethrow an error if we got one trying to run the inferior. */
const char *name = get_function_name (funaddr,
name_buf, sizeof (name_buf));
- discard_infcall_control_state (inf_status);
+ discard_infcall_control_state (inf_status.release ());
/* We could discard the dummy frame here if the program exited,
but it will get garbage collected the next time the program is
Evaluation of the expression containing the function\n\
(%s) will be abandoned.\n\
When the function is done executing, GDB will silently stop."),
- e.message, name);
+ e.what (), name);
case RETURN_QUIT:
default:
- throw_exception (e);
+ throw_exception (std::move (e));
}
}
/* If we try to restore the inferior status,
we'll crash as the inferior is no longer running. */
- discard_infcall_control_state (inf_status);
+ discard_infcall_control_state (inf_status.release ());
/* We could discard the dummy frame here given that the program exited,
but it will get garbage collected the next time the program is
name);
}
- if (! ptid_equal (call_thread_ptid, inferior_ptid))
+ if (call_thread_ptid != inferior_ptid)
{
const char *name = get_function_name (funaddr,
name_buf, sizeof (name_buf));
signal or breakpoint while our thread was running.
There's no point in restoring the inferior status,
we're in a different thread. */
- discard_infcall_control_state (inf_status);
+ discard_infcall_control_state (inf_status.release ());
/* Keep the dummy frame record, if the user switches back to the
thread with the hand-call, we'll need it. */
if (stopped_by_random_signal)
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. */
+ std::string name = get_function_name (funaddr, name_buf,
+ sizeof (name_buf));
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.get ());
/* We also need to restore inferior status to that before the
dummy call. */
- restore_infcall_control_state (inf_status);
+ restore_infcall_control_state (inf_status.release ());
/* FIXME: Insert a bunch of wrap_here; name can be very
long if it's a C++ name with arguments and stuff. */
To change this behavior use \"set unwindonsignal off\".\n\
Evaluation of the expression containing the function\n\
(%s) will be abandoned."),
- name);
+ name.c_str ());
}
else
{
(default).
Discard inferior status, we're not at the same point
we started at. */
- discard_infcall_control_state (inf_status);
+ discard_infcall_control_state (inf_status.release ());
/* FIXME: Insert a bunch of wrap_here; name can be very
long if it's a C++ name with arguments and stuff. */
Evaluation of the expression containing the function\n\
(%s) will be abandoned.\n\
When the function is done executing, GDB will silently stop."),
- name);
+ name.c_str ());
}
}
{
/* 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.get ());
/* We also need to restore inferior status to that before
the dummy call. */
- restore_infcall_control_state (inf_status);
+ restore_infcall_control_state (inf_status.release ());
error (_("\
The program being debugged entered a std::terminate call, most likely\n\
To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
Evaluation of the expression containing the function (%s)\n\
will be abandoned."),
- name);
+ name.c_str ());
}
else if (stop_stack_dummy == STOP_NONE)
{
Keep the dummy frame, the user may want to examine its state.
Discard inferior status, we're not at the same point
we started at. */
- discard_infcall_control_state (inf_status);
+ discard_infcall_control_state (inf_status.release ());
/* The following error message used to say "The expression
which contained the function call has been discarded."
Evaluation of the expression containing the function\n\
(%s) will be abandoned.\n\
When the function is done executing, GDB will silently stop."),
- name);
+ name.c_str ());
}
- /* 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 (lang_struct_return)
- 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
-
-/* Provide a prototype to silence -Wmissing-prototypes. */
-void _initialize_infcall (void);
void
_initialize_infcall (void)
{
+ add_setshow_boolean_cmd ("may-call-functions", no_class,
+ &may_call_functions_p, _("\
+Set permission to call functions in the program."), _("\
+Show permission to call functions in the program."), _("\
+When this permission is on, GDB may call functions in the program.\n\
+Otherwise, any sort of attempt to call a function in the program\n\
+will result in an error."),
+ NULL,
+ show_may_call_functions_p,
+ &setlist, &showlist);
+
add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
&coerce_float_to_double_p, _("\
Set coercion of floats to doubles when calling functions."), _("\
-Show coercion of floats to doubles when calling functions"), _("\
+Show coercion of floats to doubles when calling functions."), _("\
Variables of type float should generally be converted to doubles before\n\
calling an unprototyped function, and left alone when calling a prototyped\n\
function. However, some older debug info formats do not provide enough\n\
information to determine that a function is prototyped. If this flag is\n\
set, GDB will perform the conversion for a function it considers\n\
unprototyped.\n\
-The default is to perform the conversion.\n"),
+The default is to perform the conversion."),
NULL,
show_coerce_float_to_double_p,
&setlist, &showlist);