value);
}
+/* This boolean tells what gdb should do if a std::terminate call is
+ made while in a function called from gdb (call dummy).
+ As the confines of a single dummy stack prohibit out-of-frame
+ handlers from handling a raised exception, and as out-of-frame
+ handlers are common in C++, this can lead to no handler being found
+ by the unwinder, and a std::terminate call. This is a false positive.
+ If set, gdb unwinds the stack and restores the context to what it
+ was before the call.
+
+ The default is to unwind the frame if a std::terminate call is
+ made. */
+
+static int unwind_on_terminating_exception_p = 1;
+
+static void
+show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c,
+ const char *value)
+
+{
+ fprintf_filtered (file, _("\
+Unwind stack if a C++ exception is unhandled while in a call dummy is %s.\n"),
+ value);
+}
/* Perform the standard coercions that are specified
for arguments to be passed to C or Ada functions.
/* Perform any Ada-specific coercion first. */
if (current_language->la_language == language_ada)
- arg = ada_convert_actual (arg, type, sp);
+ arg = ada_convert_actual (arg, type, gdbarch, sp);
/* Force the value to the target if we will need its address. At
this point, we could allocate arguments on the stack instead of
find_function_addr (struct value *function, struct type **retval_type)
{
struct type *ftype = check_typedef (value_type (function));
+ struct gdbarch *gdbarch = get_type_arch (ftype);
enum type_code code = TYPE_CODE (ftype);
struct type *value_type = NULL;
CORE_ADDR funaddr;
/* Determine address to call. */
if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
{
- funaddr = VALUE_ADDRESS (function);
+ funaddr = value_address (function);
value_type = TYPE_TARGET_TYPE (ftype);
}
else if (code == TYPE_CODE_PTR)
if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
|| TYPE_CODE (ftype) == TYPE_CODE_METHOD)
{
- funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
- funaddr,
+ funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
¤t_target);
value_type = TYPE_TARGET_TYPE (ftype);
}
CORE_ADDR nfunaddr;
funaddr = value_as_address (value_addr (function));
nfunaddr = funaddr;
- funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
- funaddr,
+ funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
¤t_target);
if (funaddr != nfunaddr)
found_descriptor = 1;
if (retval_type != NULL)
*retval_type = value_type;
- return funaddr + gdbarch_deprecated_function_start_offset (current_gdbarch);
+ return funaddr + gdbarch_deprecated_function_start_offset (gdbarch);
}
/* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
struct cleanup *args_cleanup;
struct frame_info *frame;
struct gdbarch *gdbarch;
+ struct breakpoint *terminate_bp = NULL;
+ struct minimal_symbol *tm;
ptid_t call_thread_ptid;
struct gdb_exception e;
const char *name;
/* Tell the target specific argument pushing routine not to
expect a value. */
- target_values_type = builtin_type_void;
+ target_values_type = builtin_type (gdbarch)->builtin_void;
}
else
{
- struct_return = using_struct_return (value_type (function), values_type);
+ struct_return = using_struct_return (gdbarch,
+ value_type (function), values_type);
target_values_type = values_type;
}
real_pc = funaddr;
dummy_addr = entry_point_address ();
- /* Make certain that the address points at real code, and not a
- function descriptor. */
- dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch,
- dummy_addr,
- ¤t_target);
/* A call dummy always consists of just a single breakpoint, so
its address is the same as the address of the dummy. */
bp_addr = dummy_addr;
sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL);
real_pc = funaddr;
if (sym)
- dummy_addr = SYMBOL_VALUE_ADDRESS (sym);
+ {
+ dummy_addr = SYMBOL_VALUE_ADDRESS (sym);
+ /* Make certain that the address points at real code, and not
+ a function descriptor. */
+ dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch,
+ dummy_addr,
+ ¤t_target);
+ }
else
dummy_addr = entry_point_address ();
- /* Make certain that the address points at real code, and not
- a function descriptor. */
- dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch,
- dummy_addr,
- ¤t_target);
/* A call dummy always consists of just a single breakpoint,
so it's address is the same as the address of the dummy. */
bp_addr = dummy_addr;
/* 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 (sal, dummy_id, bp_call_dummy);
+ bpt = set_momentary_breakpoint (gdbarch, sal, dummy_id, bp_call_dummy);
bpt->disposition = disp_del;
}
+ /* 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)
+ {
+ struct minimal_symbol *tm = lookup_minimal_symbol ("std::terminate()",
+ NULL, NULL);
+ if (tm != NULL)
+ terminate_bp = set_momentary_breakpoint_at_pc
+ (gdbarch, SYMBOL_VALUE_ADDRESS (tm), bp_breakpoint);
+ }
+
/* Everything's ready, push all the info needed to restore the
caller (and identify the dummy-frame) onto the dummy-frame
stack. */
or discard it. */
discard_cleanups (inf_status_cleanup);
+ /* Register a clean-up for unwind_on_terminating_exception_breakpoint. */
+ if (terminate_bp)
+ make_cleanup_delete_breakpoint (terminate_bp);
+
/* - 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.. */
if (!stop_stack_dummy)
{
+
+ /* Check if unwind on terminating exception behaviour is on. */
+ if (unwind_on_terminating_exception_p)
+ {
+ /* Check that the breakpoint is our special std::terminate
+ breakpoint. If it is, we do not want to kill the inferior
+ in an inferior function call. Rewind, and warn the
+ user. */
+
+ if (terminate_bp != NULL
+ && (inferior_thread()->stop_bpstat->breakpoint_at->address
+ == terminate_bp->loc->address))
+ {
+ /* 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_inferior_status (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);
+ }
+ }
/* 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
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);
+
}
projects / deliverable / binutils-gdb.git / blobdiff