1132 lines
39 KiB
C
1132 lines
39 KiB
C
/* Perform an inferior function call, for GDB, the GNU debugger.
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Copyright (C) 1986-2014 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "breakpoint.h"
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#include "tracepoint.h"
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#include "target.h"
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#include "regcache.h"
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#include "inferior.h"
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#include "gdb_assert.h"
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#include "block.h"
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#include "gdbcore.h"
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#include "language.h"
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#include "objfiles.h"
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#include "gdbcmd.h"
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#include "command.h"
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#include <string.h>
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#include "infcall.h"
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#include "dummy-frame.h"
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#include "ada-lang.h"
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#include "gdbthread.h"
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#include "exceptions.h"
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/* If we can't find a function's name from its address,
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we print this instead. */
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#define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s"
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#define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \
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+ 2 * sizeof (CORE_ADDR))
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/* NOTE: cagney/2003-04-16: What's the future of this code?
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GDB needs an asynchronous expression evaluator, that means an
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asynchronous inferior function call implementation, and that in
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turn means restructuring the code so that it is event driven. */
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/* How you should pass arguments to a function depends on whether it
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was defined in K&R style or prototype style. If you define a
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function using the K&R syntax that takes a `float' argument, then
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callers must pass that argument as a `double'. If you define the
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function using the prototype syntax, then you must pass the
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argument as a `float', with no promotion.
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Unfortunately, on certain older platforms, the debug info doesn't
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indicate reliably how each function was defined. A function type's
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TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
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defined in prototype style. When calling a function whose
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TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
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decide what to do.
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For modern targets, it is proper to assume that, if the prototype
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flag is clear, that can be trusted: `float' arguments should be
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promoted to `double'. For some older targets, if the prototype
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flag is clear, that doesn't tell us anything. The default is to
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trust the debug information; the user can override this behavior
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with "set coerce-float-to-double 0". */
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static int coerce_float_to_double_p = 1;
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static void
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show_coerce_float_to_double_p (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file,
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_("Coercion of floats to doubles "
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"when calling functions is %s.\n"),
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value);
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}
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/* This boolean tells what gdb should do if a signal is received while
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in a function called from gdb (call dummy). If set, gdb unwinds
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the stack and restore the context to what as it was before the
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call.
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The default is to stop in the frame where the signal was received. */
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static int unwind_on_signal_p = 0;
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static void
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show_unwind_on_signal_p (struct ui_file *file, int from_tty,
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struct cmd_list_element *c, const char *value)
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{
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fprintf_filtered (file,
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_("Unwinding of stack if a signal is "
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"received while in a call dummy is %s.\n"),
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value);
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}
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/* This boolean tells what gdb should do if a std::terminate call is
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made while in a function called from gdb (call dummy).
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As the confines of a single dummy stack prohibit out-of-frame
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handlers from handling a raised exception, and as out-of-frame
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handlers are common in C++, this can lead to no handler being found
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by the unwinder, and a std::terminate call. This is a false positive.
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If set, gdb unwinds the stack and restores the context to what it
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was before the call.
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The default is to unwind the frame if a std::terminate call is
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made. */
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static int unwind_on_terminating_exception_p = 1;
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static void
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show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
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struct cmd_list_element *c,
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const char *value)
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{
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fprintf_filtered (file,
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_("Unwind stack if a C++ exception is "
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"unhandled while in a call dummy is %s.\n"),
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value);
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}
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/* Perform the standard coercions that are specified
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for arguments to be passed to C or Ada functions.
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If PARAM_TYPE is non-NULL, it is the expected parameter type.
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IS_PROTOTYPED is non-zero if the function declaration is prototyped.
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SP is the stack pointer were additional data can be pushed (updating
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its value as needed). */
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static struct value *
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value_arg_coerce (struct gdbarch *gdbarch, struct value *arg,
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struct type *param_type, int is_prototyped, CORE_ADDR *sp)
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{
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const struct builtin_type *builtin = builtin_type (gdbarch);
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struct type *arg_type = check_typedef (value_type (arg));
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struct type *type
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= param_type ? check_typedef (param_type) : arg_type;
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/* Perform any Ada-specific coercion first. */
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if (current_language->la_language == language_ada)
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arg = ada_convert_actual (arg, type);
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/* Force the value to the target if we will need its address. At
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this point, we could allocate arguments on the stack instead of
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calling malloc if we knew that their addresses would not be
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saved by the called function. */
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arg = value_coerce_to_target (arg);
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switch (TYPE_CODE (type))
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{
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case TYPE_CODE_REF:
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{
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struct value *new_value;
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if (TYPE_CODE (arg_type) == TYPE_CODE_REF)
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return value_cast_pointers (type, arg, 0);
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/* Cast the value to the reference's target type, and then
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convert it back to a reference. This will issue an error
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if the value was not previously in memory - in some cases
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we should clearly be allowing this, but how? */
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new_value = value_cast (TYPE_TARGET_TYPE (type), arg);
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new_value = value_ref (new_value);
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return new_value;
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}
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case TYPE_CODE_INT:
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case TYPE_CODE_CHAR:
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case TYPE_CODE_BOOL:
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case TYPE_CODE_ENUM:
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/* If we don't have a prototype, coerce to integer type if necessary. */
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if (!is_prototyped)
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{
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if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
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type = builtin->builtin_int;
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}
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/* Currently all target ABIs require at least the width of an integer
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type for an argument. We may have to conditionalize the following
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type coercion for future targets. */
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if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
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type = builtin->builtin_int;
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break;
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case TYPE_CODE_FLT:
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if (!is_prototyped && coerce_float_to_double_p)
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{
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if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double))
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type = builtin->builtin_double;
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else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double))
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type = builtin->builtin_long_double;
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}
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break;
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case TYPE_CODE_FUNC:
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type = lookup_pointer_type (type);
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break;
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case TYPE_CODE_ARRAY:
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/* Arrays are coerced to pointers to their first element, unless
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they are vectors, in which case we want to leave them alone,
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because they are passed by value. */
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if (current_language->c_style_arrays)
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if (!TYPE_VECTOR (type))
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type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
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break;
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case TYPE_CODE_UNDEF:
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case TYPE_CODE_PTR:
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case TYPE_CODE_STRUCT:
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case TYPE_CODE_UNION:
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case TYPE_CODE_VOID:
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case TYPE_CODE_SET:
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case TYPE_CODE_RANGE:
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case TYPE_CODE_STRING:
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case TYPE_CODE_ERROR:
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case TYPE_CODE_MEMBERPTR:
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case TYPE_CODE_METHODPTR:
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case TYPE_CODE_METHOD:
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case TYPE_CODE_COMPLEX:
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default:
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break;
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}
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return value_cast (type, arg);
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}
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/* Return the return type of a function with its first instruction exactly at
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the PC address. Return NULL otherwise. */
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static struct type *
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find_function_return_type (CORE_ADDR pc)
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{
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struct symbol *sym = find_pc_function (pc);
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if (sym != NULL && BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) == pc
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&& SYMBOL_TYPE (sym) != NULL)
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return TYPE_TARGET_TYPE (SYMBOL_TYPE (sym));
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return NULL;
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}
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/* Determine a function's address and its return type from its value.
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Calls error() if the function is not valid for calling. */
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CORE_ADDR
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find_function_addr (struct value *function, struct type **retval_type)
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{
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struct type *ftype = check_typedef (value_type (function));
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struct gdbarch *gdbarch = get_type_arch (ftype);
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struct type *value_type = NULL;
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/* Initialize it just to avoid a GCC false warning. */
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CORE_ADDR funaddr = 0;
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/* If it's a member function, just look at the function
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part of it. */
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/* Determine address to call. */
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if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
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|| TYPE_CODE (ftype) == TYPE_CODE_METHOD)
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funaddr = value_address (function);
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else if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
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{
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funaddr = value_as_address (function);
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ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
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if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
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|| TYPE_CODE (ftype) == TYPE_CODE_METHOD)
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funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
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¤t_target);
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}
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if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
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|| TYPE_CODE (ftype) == TYPE_CODE_METHOD)
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{
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value_type = TYPE_TARGET_TYPE (ftype);
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if (TYPE_GNU_IFUNC (ftype))
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{
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funaddr = gnu_ifunc_resolve_addr (gdbarch, funaddr);
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/* Skip querying the function symbol if no RETVAL_TYPE has been
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asked for. */
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if (retval_type)
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value_type = find_function_return_type (funaddr);
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}
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}
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else if (TYPE_CODE (ftype) == TYPE_CODE_INT)
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{
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/* Handle the case of functions lacking debugging info.
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Their values are characters since their addresses are char. */
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if (TYPE_LENGTH (ftype) == 1)
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funaddr = value_as_address (value_addr (function));
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else
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{
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/* Handle function descriptors lacking debug info. */
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int found_descriptor = 0;
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funaddr = 0; /* pacify "gcc -Werror" */
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if (VALUE_LVAL (function) == lval_memory)
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{
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CORE_ADDR nfunaddr;
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funaddr = value_as_address (value_addr (function));
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nfunaddr = funaddr;
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funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
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¤t_target);
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if (funaddr != nfunaddr)
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found_descriptor = 1;
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}
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if (!found_descriptor)
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/* Handle integer used as address of a function. */
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funaddr = (CORE_ADDR) value_as_long (function);
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}
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}
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else
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error (_("Invalid data type for function to be called."));
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if (retval_type != NULL)
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*retval_type = value_type;
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return funaddr + gdbarch_deprecated_function_start_offset (gdbarch);
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}
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/* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
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function returns to. */
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static CORE_ADDR
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push_dummy_code (struct gdbarch *gdbarch,
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CORE_ADDR sp, CORE_ADDR funaddr,
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struct value **args, int nargs,
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struct type *value_type,
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CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
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struct regcache *regcache)
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{
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gdb_assert (gdbarch_push_dummy_code_p (gdbarch));
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return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
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args, nargs, value_type, real_pc, bp_addr,
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regcache);
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}
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/* Fetch the name of the function at FUNADDR.
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||
This is used in printing an error message for call_function_by_hand.
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BUF is used to print FUNADDR in hex if the function name cannot be
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determined. It must be large enough to hold formatted result of
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RAW_FUNCTION_ADDRESS_FORMAT. */
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static const char *
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get_function_name (CORE_ADDR funaddr, char *buf, int buf_size)
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{
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{
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struct symbol *symbol = find_pc_function (funaddr);
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if (symbol)
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return SYMBOL_PRINT_NAME (symbol);
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}
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{
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/* Try the minimal symbols. */
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struct bound_minimal_symbol msymbol = lookup_minimal_symbol_by_pc (funaddr);
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||
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if (msymbol.minsym)
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||
return SYMBOL_PRINT_NAME (msymbol.minsym);
|
||
}
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||
|
||
{
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||
char *tmp = xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT),
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hex_string (funaddr));
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gdb_assert (strlen (tmp) + 1 <= buf_size);
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strcpy (buf, tmp);
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xfree (tmp);
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return buf;
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||
}
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}
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|
||
/* Subroutine of call_function_by_hand to simplify it.
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Start up the inferior and wait for it to stop.
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Return the exception if there's an error, or an exception with
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||
reason >= 0 if there's no error.
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||
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This is done inside a TRY_CATCH so the caller needn't worry about
|
||
thrown errors. The caller should rethrow if there's an error. */
|
||
|
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static struct gdb_exception
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run_inferior_call (struct thread_info *call_thread, CORE_ADDR real_pc)
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||
{
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||
volatile struct gdb_exception e;
|
||
int saved_in_infcall = call_thread->control.in_infcall;
|
||
ptid_t call_thread_ptid = call_thread->ptid;
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||
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call_thread->control.in_infcall = 1;
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||
|
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clear_proceed_status ();
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||
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||
disable_watchpoints_before_interactive_call_start ();
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||
|
||
/* We want stop_registers, please... */
|
||
call_thread->control.proceed_to_finish = 1;
|
||
|
||
TRY_CATCH (e, RETURN_MASK_ALL)
|
||
{
|
||
proceed (real_pc, GDB_SIGNAL_0, 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 ();
|
||
}
|
||
}
|
||
|
||
/* 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);
|
||
|
||
enable_watchpoints_after_interactive_call_stop ();
|
||
|
||
/* Call breakpoint_auto_delete on the current contents of the bpstat
|
||
of inferior call thread.
|
||
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 (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;
|
||
}
|
||
|
||
/* A cleanup function that calls delete_std_terminate_breakpoint. */
|
||
static void
|
||
cleanup_delete_std_terminate_breakpoint (void *ignore)
|
||
{
|
||
delete_std_terminate_breakpoint ();
|
||
}
|
||
|
||
/* 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
|
||
function and then hit a breakpoint (get a signal, etc), "backtrace"
|
||
will look right. Whether the backtrace needs to actually show the
|
||
stack at the time the inferior function was called is debatable, but
|
||
it certainly needs to not display garbage. So if you are contemplating
|
||
making dummy frames be different from normal frames, consider that. */
|
||
|
||
/* Perform a function call in the inferior.
|
||
ARGS is a vector of values of arguments (NARGS of them).
|
||
FUNCTION is a value, the function to be called.
|
||
Returns a value representing what the function returned.
|
||
May fail to return, if a breakpoint or signal is hit
|
||
during the execution of the function.
|
||
|
||
ARGS is modified to contain coerced values. */
|
||
|
||
struct value *
|
||
call_function_by_hand (struct value *function, int nargs, struct value **args)
|
||
{
|
||
CORE_ADDR sp;
|
||
struct type *values_type, *target_values_type;
|
||
unsigned char struct_return = 0, hidden_first_param_p = 0;
|
||
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 (!target_has_execution)
|
||
noprocess ();
|
||
|
||
if (get_traceframe_number () >= 0)
|
||
error (_("May not call functions while looking at trace frames."));
|
||
|
||
if (execution_direction == EXEC_REVERSE)
|
||
error (_("Cannot call functions in reverse mode."));
|
||
|
||
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.
|
||
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);
|
||
|
||
/* 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);
|
||
|
||
/* Ensure that the initial SP is correctly aligned. */
|
||
{
|
||
CORE_ADDR old_sp = get_frame_sp (frame);
|
||
|
||
if (gdbarch_frame_align_p (gdbarch))
|
||
{
|
||
sp = gdbarch_frame_align (gdbarch, old_sp);
|
||
/* NOTE: cagney/2003-08-13: Skip the "red zone". For some
|
||
ABIs, a function can use memory beyond the inner most stack
|
||
address. AMD64 called that region the "red zone". Skip at
|
||
least the "red zone" size before allocating any space on
|
||
the stack. */
|
||
if (gdbarch_inner_than (gdbarch, 1, 2))
|
||
sp -= gdbarch_frame_red_zone_size (gdbarch);
|
||
else
|
||
sp += gdbarch_frame_red_zone_size (gdbarch);
|
||
/* Still aligned? */
|
||
gdb_assert (sp == gdbarch_frame_align (gdbarch, sp));
|
||
/* NOTE: cagney/2002-09-18:
|
||
|
||
On a RISC architecture, a void parameterless generic dummy
|
||
frame (i.e., no parameters, no result) typically does not
|
||
need to push anything the stack and hence can leave SP and
|
||
FP. Similarly, a frameless (possibly leaf) function does
|
||
not push anything on the stack and, hence, that too can
|
||
leave FP and SP unchanged. As a consequence, a sequence of
|
||
void parameterless generic dummy frame calls to frameless
|
||
functions will create a sequence of effectively identical
|
||
frames (SP, FP and TOS and PC the same). This, not
|
||
suprisingly, results in what appears to be a stack in an
|
||
infinite loop --- when GDB tries to find a generic dummy
|
||
frame on the internal dummy frame stack, it will always
|
||
find the first one.
|
||
|
||
To avoid this problem, the code below always grows the
|
||
stack. That way, two dummy frames can never be identical.
|
||
It does burn a few bytes of stack but that is a small price
|
||
to pay :-). */
|
||
if (sp == old_sp)
|
||
{
|
||
if (gdbarch_inner_than (gdbarch, 1, 2))
|
||
/* Stack grows down. */
|
||
sp = gdbarch_frame_align (gdbarch, old_sp - 1);
|
||
else
|
||
/* Stack grows up. */
|
||
sp = gdbarch_frame_align (gdbarch, old_sp + 1);
|
||
}
|
||
/* SP may have underflown address zero here from OLD_SP. Memory access
|
||
functions will probably fail in such case but that is a target's
|
||
problem. */
|
||
}
|
||
else
|
||
/* FIXME: cagney/2002-09-18: Hey, you loose!
|
||
|
||
Who knows how badly aligned the SP is!
|
||
|
||
If the generic dummy frame ends up empty (because nothing is
|
||
pushed) GDB won't be able to correctly perform back traces.
|
||
If a target is having trouble with backtraces, first thing to
|
||
do is add FRAME_ALIGN() to the architecture vector. If that
|
||
fails, try dummy_id().
|
||
|
||
If the ABI specifies a "Red Zone" (see the doco) the code
|
||
below will quietly trash it. */
|
||
sp = old_sp;
|
||
}
|
||
|
||
funaddr = find_function_addr (function, &values_type);
|
||
if (!values_type)
|
||
values_type = builtin_type (gdbarch)->builtin_int;
|
||
|
||
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. */
|
||
|
||
if (gdbarch_return_in_first_hidden_param_p (gdbarch, values_type))
|
||
{
|
||
hidden_first_param_p = 1;
|
||
|
||
/* Tell the target specific argument pushing routine not to
|
||
expect a value. */
|
||
target_values_type = builtin_type (gdbarch)->builtin_void;
|
||
}
|
||
else
|
||
{
|
||
struct_return = using_struct_return (gdbarch, function, values_type);
|
||
target_values_type = values_type;
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
switch (gdbarch_call_dummy_location (gdbarch))
|
||
{
|
||
case ON_STACK:
|
||
{
|
||
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, nargs,
|
||
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:
|
||
{
|
||
CORE_ADDR dummy_addr;
|
||
|
||
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.
|
||
|
||
The actual breakpoint is inserted separatly so there is no need to
|
||
write that out. */
|
||
bp_addr = dummy_addr;
|
||
break;
|
||
}
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("bad switch"));
|
||
}
|
||
|
||
if (nargs < 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)
|
||
prototyped = 1;
|
||
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;
|
||
|
||
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]);
|
||
}
|
||
}
|
||
|
||
/* Reserve space for the return structure to be written on the
|
||
stack, if necessary. Make certain that the value is correctly
|
||
aligned. */
|
||
|
||
if (struct_return || hidden_first_param_p)
|
||
{
|
||
if (gdbarch_inner_than (gdbarch, 1, 2))
|
||
{
|
||
/* Stack grows downward. Align STRUCT_ADDR and SP after
|
||
making space for the return value. */
|
||
sp -= TYPE_LENGTH (values_type);
|
||
if (gdbarch_frame_align_p (gdbarch))
|
||
sp = gdbarch_frame_align (gdbarch, sp);
|
||
struct_addr = sp;
|
||
}
|
||
else
|
||
{
|
||
/* Stack grows upward. Align the frame, allocate space, and
|
||
then again, re-align the frame??? */
|
||
if (gdbarch_frame_align_p (gdbarch))
|
||
sp = gdbarch_frame_align (gdbarch, sp);
|
||
struct_addr = sp;
|
||
sp += TYPE_LENGTH (values_type);
|
||
if (gdbarch_frame_align_p (gdbarch))
|
||
sp = gdbarch_frame_align (gdbarch, sp);
|
||
}
|
||
}
|
||
|
||
if (hidden_first_param_p)
|
||
{
|
||
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);
|
||
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);
|
||
|
||
/* 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
|
||
ID so that the breakpoint code can correctly re-identify the
|
||
dummy breakpoint. */
|
||
/* 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. */
|
||
dummy_id = frame_id_build (sp, bp_addr);
|
||
|
||
/* Create a momentary breakpoint at the return address of the
|
||
inferior. That way it breaks when it returns. */
|
||
|
||
{
|
||
struct breakpoint *bpt, *longjmp_b;
|
||
struct symtab_and_line sal;
|
||
|
||
init_sal (&sal); /* initialize to zeroes */
|
||
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);
|
||
|
||
/* 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 ();
|
||
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.
|
||
If a C++ exception is raised in the dummy-frame, and the
|
||
exception handler is (normally, and expected to be) out-of-frame,
|
||
the default C++ handler will (wrongly) be called in an inferior
|
||
function call. This is wrong, as an exception can be normally
|
||
and legally handled out-of-frame. The confines of the dummy frame
|
||
prevent the unwinder from finding the correct handler (or any
|
||
handler, unless it is in-frame). The default handler calls
|
||
std::terminate. This will kill the inferior. Assert that
|
||
terminate should never be called in an inferior function
|
||
call. Place a momentary breakpoint in the std::terminate function
|
||
and if triggered in the call, rewind. */
|
||
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);
|
||
|
||
/* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
|
||
terminate_bp_cleanup = make_cleanup (cleanup_delete_std_terminate_breakpoint,
|
||
NULL);
|
||
|
||
/* - 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 ();
|
||
|
||
/* Save this thread's ptid, we need it later but the thread
|
||
may have exited. */
|
||
call_thread_ptid = tp->ptid;
|
||
|
||
/* Run the inferior until it stops. */
|
||
|
||
e = run_inferior_call (tp, real_pc);
|
||
}
|
||
|
||
/* Rethrow an error if we got one trying to run the inferior. */
|
||
|
||
if (e.reason < 0)
|
||
{
|
||
const char *name = get_function_name (funaddr,
|
||
name_buf, sizeof (name_buf));
|
||
|
||
discard_infcall_control_state (inf_status);
|
||
|
||
/* We could discard the dummy frame here if the program exited,
|
||
but it will get garbage collected the next time the program is
|
||
run anyway. */
|
||
|
||
switch (e.reason)
|
||
{
|
||
case RETURN_ERROR:
|
||
throw_error (e.error, _("%s\n\
|
||
An error occurred while in a function called from GDB.\n\
|
||
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);
|
||
case RETURN_QUIT:
|
||
default:
|
||
throw_exception (e);
|
||
}
|
||
}
|
||
|
||
/* If the program has exited, or we stopped at a different thread,
|
||
exit and inform the user. */
|
||
|
||
if (! target_has_execution)
|
||
{
|
||
const char *name = get_function_name (funaddr,
|
||
name_buf, sizeof (name_buf));
|
||
|
||
/* If we try to restore the inferior status,
|
||
we'll crash as the inferior is no longer running. */
|
||
discard_infcall_control_state (inf_status);
|
||
|
||
/* We could discard the dummy frame here given that the program exited,
|
||
but it will get garbage collected the next time the program is
|
||
run anyway. */
|
||
|
||
error (_("The program being debugged exited while in a function "
|
||
"called from GDB.\n"
|
||
"Evaluation of the expression containing the function\n"
|
||
"(%s) will be abandoned."),
|
||
name);
|
||
}
|
||
|
||
if (! ptid_equal (call_thread_ptid, inferior_ptid))
|
||
{
|
||
const char *name = get_function_name (funaddr,
|
||
name_buf, sizeof (name_buf));
|
||
|
||
/* We've switched threads. This can happen if another thread gets a
|
||
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);
|
||
/* 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)
|
||
error (_("\
|
||
The program received a signal in another thread while\n\
|
||
making a function call from GDB.\n\
|
||
Evaluation of the expression containing the function\n\
|
||
(%s) will be abandoned.\n\
|
||
When the function is done executing, GDB will silently stop."),
|
||
name);
|
||
else
|
||
error (_("\
|
||
The program stopped in another thread while making a function call from GDB.\n\
|
||
Evaluation of the expression containing the function\n\
|
||
(%s) will be abandoned.\n\
|
||
When the function is done executing, GDB will silently stop."),
|
||
name);
|
||
}
|
||
|
||
if (stopped_by_random_signal || stop_stack_dummy != STOP_STACK_DUMMY)
|
||
{
|
||
const char *name = get_function_name (funaddr,
|
||
name_buf, sizeof (name_buf));
|
||
|
||
if (stopped_by_random_signal)
|
||
{
|
||
/* We stopped inside the FUNCTION because of a random
|
||
signal. Further execution of the FUNCTION is not
|
||
allowed. */
|
||
|
||
if (unwind_on_signal_p)
|
||
{
|
||
/* The user wants the context restored. */
|
||
|
||
/* We must get back to the frame we were before the
|
||
dummy call. */
|
||
dummy_frame_pop (dummy_id);
|
||
|
||
/* We also need to restore inferior status to that before the
|
||
dummy call. */
|
||
restore_infcall_control_state (inf_status);
|
||
|
||
/* FIXME: Insert a bunch of wrap_here; name can be very
|
||
long if it's a C++ name with arguments and stuff. */
|
||
error (_("\
|
||
The program being debugged was signaled while in a function called from GDB.\n\
|
||
GDB has restored the context to what it was before the call.\n\
|
||
To change this behavior use \"set unwindonsignal off\".\n\
|
||
Evaluation of the expression containing the function\n\
|
||
(%s) will be abandoned."),
|
||
name);
|
||
}
|
||
else
|
||
{
|
||
/* The user wants to stay in the frame where we stopped
|
||
(default).
|
||
Discard inferior status, we're not at the same point
|
||
we started at. */
|
||
discard_infcall_control_state (inf_status);
|
||
|
||
/* FIXME: Insert a bunch of wrap_here; name can be very
|
||
long if it's a C++ name with arguments and stuff. */
|
||
error (_("\
|
||
The program being debugged was signaled while in a function called from GDB.\n\
|
||
GDB remains in the frame where the signal was received.\n\
|
||
To change this behavior use \"set unwindonsignal on\".\n\
|
||
Evaluation of the expression containing the function\n\
|
||
(%s) will be abandoned.\n\
|
||
When the function is done executing, GDB will silently stop."),
|
||
name);
|
||
}
|
||
}
|
||
|
||
if (stop_stack_dummy == STOP_STD_TERMINATE)
|
||
{
|
||
/* We must get back to the frame we were before the dummy
|
||
call. */
|
||
dummy_frame_pop (dummy_id);
|
||
|
||
/* We also need to restore inferior status to that before
|
||
the dummy call. */
|
||
restore_infcall_control_state (inf_status);
|
||
|
||
error (_("\
|
||
The program being debugged entered a std::terminate call, most likely\n\
|
||
caused by an unhandled C++ exception. GDB blocked this call in order\n\
|
||
to prevent the program from being terminated, and has restored the\n\
|
||
context to its original state before the call.\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);
|
||
}
|
||
else if (stop_stack_dummy == STOP_NONE)
|
||
{
|
||
|
||
/* We hit a breakpoint inside the FUNCTION.
|
||
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);
|
||
|
||
/* The following error message used to say "The expression
|
||
which contained the function call has been discarded."
|
||
It is a hard concept to explain in a few words. Ideally,
|
||
GDB would be able to resume evaluation of the expression
|
||
when the function finally is done executing. Perhaps
|
||
someday this will be implemented (it would not be easy). */
|
||
/* FIXME: Insert a bunch of wrap_here; name can be very long if it's
|
||
a C++ name with arguments and stuff. */
|
||
error (_("\
|
||
The program being debugged stopped while in a function called from GDB.\n\
|
||
Evaluation of the expression containing the function\n\
|
||
(%s) will be abandoned.\n\
|
||
When the function is done executing, GDB will silently stop."),
|
||
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;
|
||
}
|
||
}
|
||
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
void _initialize_infcall (void);
|
||
|
||
void
|
||
_initialize_infcall (void)
|
||
{
|
||
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"), _("\
|
||
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"),
|
||
NULL,
|
||
show_coerce_float_to_double_p,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_boolean_cmd ("unwindonsignal", no_class,
|
||
&unwind_on_signal_p, _("\
|
||
Set unwinding of stack if a signal is received while in a call dummy."), _("\
|
||
Show unwinding of stack if a signal is received while in a call dummy."), _("\
|
||
The unwindonsignal lets the user determine what gdb should do if a signal\n\
|
||
is received while in a function called from gdb (call dummy). If set, gdb\n\
|
||
unwinds the stack and restore the context to what as it was before the call.\n\
|
||
The default is to stop in the frame where the signal was received."),
|
||
NULL,
|
||
show_unwind_on_signal_p,
|
||
&setlist, &showlist);
|
||
|
||
add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class,
|
||
&unwind_on_terminating_exception_p, _("\
|
||
Set unwinding of stack if std::terminate is called while in call dummy."), _("\
|
||
Show unwinding of stack if std::terminate() is called while in a call dummy."),
|
||
_("\
|
||
The unwind on terminating exception flag lets the user determine\n\
|
||
what gdb should do if a std::terminate() call is made from the\n\
|
||
default exception handler. If set, gdb unwinds the stack and restores\n\
|
||
the context to what it was before the call. If unset, gdb allows the\n\
|
||
std::terminate call to proceed.\n\
|
||
The default is to unwind the frame."),
|
||
NULL,
|
||
show_unwind_on_terminating_exception_p,
|
||
&setlist, &showlist);
|
||
|
||
}
|