extern NORETURN void nomem (long) ATTR_NORETURN;
-/* Reasons for calling return_to_top_level. Note: enum value 0 is
- reserved for internal use as the return value from an initial
- setjmp(). */
+/* Reasons for calling return_to_top_level. NOTE: all reason values
+ must be less than zero. enum value 0 is reserved for internal use
+ as the return value from an initial setjmp(). The function
+ catch_exceptions() reserves values >= 0 as legal results from its
+ wrapped function. */
enum return_reason
{
/* User interrupt. */
- RETURN_QUIT = 1,
+ RETURN_QUIT = -2,
/* Any other error. */
RETURN_ERROR
};
#define ALL_CLEANUPS ((struct cleanup *)0)
-#define RETURN_MASK(reason) (1 << (int)(reason))
+#define RETURN_MASK(reason) (1 << (int)(-reason))
#define RETURN_MASK_QUIT RETURN_MASK (RETURN_QUIT)
#define RETURN_MASK_ERROR RETURN_MASK (RETURN_ERROR)
#define RETURN_MASK_ALL (RETURN_MASK_QUIT | RETURN_MASK_ERROR)
extern NORETURN void return_to_top_level (enum return_reason) ATTR_NORETURN;
+/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
+ handler. If an exception (enum return_reason) is thrown using
+ return_to_top_level() than all cleanups installed since
+ catch_exceptions() was entered are invoked, the (-ve) exception
+ value is then returned by catch_exceptions. If FUNC() returns
+ normally (with a postive or zero return value) then that value is
+ returned by catch_exceptions(). It is an internal_error() for
+ FUNC() to return a negative value.
+
+ For the period of the FUNC() call: UIOUT is installed as the output
+ builder; ERRSTRING is installed as the error/quit message; and a
+ new cleanup_chain is established. The old values are restored
+ before catch_exceptions() returns.
+
+ FIXME; cagney/2001-08-13: The need to override the global UIOUT
+ builder variable should just go away.
+
+ This function superseeds catch_errors().
+
+ This function uses SETJMP() and LONGJUMP(). */
+
+struct ui_out;
+typedef int (catch_exceptions_ftype) (struct ui_out *ui_out, void *args);
+extern int catch_exceptions (struct ui_out *uiout,
+ catch_exceptions_ftype *func, void *func_args,
+ char *errstring, return_mask mask);
+
/* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
otherwize the result from CATCH_ERRORS_FTYPE is returned. It is
probably useful for CATCH_ERRORS_FTYPE to always return a non-zero
value. It's unfortunate that, catch_errors() does not return an
indication of the exact exception that it caught - quit_flag might
- help. */
+ help.
+
+ This function is superseeded by catch_exceptions(). */
typedef int (catch_errors_ftype) (PTR);
extern int catch_errors (catch_errors_ftype *, PTR, char *, return_mask);
#include "version.h"
#include "serial.h"
#include "doublest.h"
+#include "gdb_assert.h"
/* readline include files */
#include <readline/readline.h>
(NORETURN void) SIGLONGJMP (*catch_return, (int) reason);
}
-/* Call FUNC with arg ARGS, catching any errors. If there is no
- error, return the value returned by FUNC. If there is an error,
- print ERRSTRING, print the specific error message, then return
- zero.
+/* Call FUNC() with args FUNC_UIOUT and FUNC_ARGS, catching any
+ errors. Set FUNC_CAUGHT to an ``enum return_reason'' if the
+ function is aborted (using return_to_top_level() or zero if the
+ function returns normally. Set FUNC_VAL to the value returned by
+ the function or 0 if the function was aborted.
Must not be called with immediate_quit in effect (bad things might
happen, say we got a signal in the middle of a memcpy to quit_return).
be consolidated into a single file instead of being distributed
between utils.c and top.c? */
-int
-catch_errors (catch_errors_ftype *func, void * args, char *errstring,
- return_mask mask)
+static void
+catcher (catch_exceptions_ftype *func,
+ struct ui_out *func_uiout,
+ void *func_args,
+ int *func_val,
+ enum return_reason *func_caught,
+ char *errstring,
+ return_mask mask)
{
SIGJMP_BUF *saved_catch;
SIGJMP_BUF catch;
- int val;
struct cleanup *saved_cleanup_chain;
char *saved_error_pre_print;
char *saved_quit_pre_print;
+ struct ui_out *saved_uiout;
/* Return value from SIGSETJMP(): enum return_reason if error or
quit caught, 0 otherwise. */
int caught;
+ /* Return value from FUNC(): Hopefully non-zero. Explicitly set to
+ zero if an error quit was caught. */
+ int val;
+
/* Override error/quit messages during FUNC. */
saved_error_pre_print = error_pre_print;
if (mask & RETURN_MASK_QUIT)
quit_pre_print = errstring;
+ /* Override the global ``struct ui_out'' builder. */
+
+ saved_uiout = uiout;
+ uiout = func_uiout;
+
/* Prevent error/quit during FUNC from calling cleanups established
prior to here. */
catch_return = &catch;
caught = SIGSETJMP (catch);
if (!caught)
- val = (*func) (args);
+ val = (*func) (func_uiout, func_args);
else
val = 0;
catch_return = saved_catch;
do_cleanups call (to cover the problem) or an assertion check to
detect bad FUNCs code. */
- /* Restore the cleanup chain and error/quit messages to their
- original states. */
+ /* Restore the cleanup chain, the error/quit messages, and the uiout
+ builder, to their original states. */
restore_cleanups (saved_cleanup_chain);
+ uiout = saved_uiout;
+
if (mask & RETURN_MASK_QUIT)
quit_pre_print = saved_quit_pre_print;
if (mask & RETURN_MASK_ERROR)
error_pre_print = saved_error_pre_print;
- /* Return normally if no error/quit event occurred. */
+ /* Return normally if no error/quit event occurred or this catcher
+ can handle this exception. The caller analyses the func return
+ values. */
- if (!caught)
- return val;
+ if (!caught || (mask & RETURN_MASK (caught)))
+ {
+ *func_val = val;
+ *func_caught = caught;
+ return;
+ }
- /* If the caller didn't request that the event be caught, relay the
+ /* The caller didn't request that the event be caught, relay the
event to the next containing catch_errors(). */
- if (!(mask & RETURN_MASK (caught)))
- return_to_top_level (caught);
-
- /* Tell the caller that an event was caught.
-
- FIXME: nsd/2000-02-22: When MASK is RETURN_MASK_ALL, the caller
- can't tell what type of event occurred.
+ return_to_top_level (caught);
+}
- A possible fix is to add a new interface, catch_event(), that
- returns enum return_reason after catching an error or a quit.
+int
+catch_exceptions (struct ui_out *uiout,
+ catch_exceptions_ftype *func,
+ void *func_args,
+ char *errstring,
+ return_mask mask)
+{
+ int val;
+ enum return_reason caught;
+ catcher (func, uiout, func_args, &val, &caught, errstring, mask);
+ gdb_assert (val >= 0);
+ gdb_assert (caught <= 0);
+ if (caught < 0)
+ return caught;
+ return val;
+}
- When returning normally, i.e. without catching an error or a
- quit, catch_event() could return RETURN_NORMAL, which would be
- added to enum return_reason. FUNC would return information
- exclusively via ARGS.
+struct catch_errors_args
+{
+ catch_errors_ftype *func;
+ void *func_args;
+};
- Alternatively, normal catch_event() could return FUNC's return
- value. The caller would need to be aware of potential overlap
- with enum return_reason, which could be publicly restricted to
- negative values to simplify return value processing in FUNC and
- in the caller. */
+int
+do_catch_errors (struct ui_out *uiout, void *data)
+{
+ struct catch_errors_args *args = data;
+ return args->func (args->func_args);
+}
- return 0;
+int
+catch_errors (catch_errors_ftype *func, void *func_args, char *errstring,
+ return_mask mask)
+{
+ int val;
+ enum return_reason caught;
+ struct catch_errors_args args;
+ args.func = func;
+ args.func_args = func_args;
+ catcher (do_catch_errors, uiout, &args, &val, &caught, errstring, mask);
+ if (caught != 0)
+ return 0;
+ return val;
}
struct captured_command_args
projects / binutils-gdb.git / commitdiff