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/***********************************************************************/
/* */
/* Caml Special Light */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1995 Institut National de Recherche en Informatique et */
/* Automatique. Distributed only by permission. */
/* */
/***********************************************************************/
/* $Id$ */
/* Raising exceptions from C. */
#include <signal.h>
#include "alloc.h"
#include "fail.h"
#include "gc.h"
#include "memory.h"
#include "mlvalues.h"
#include "roots.h"
#include "signals.h"
#include "stack.h"
/* The globals holding predefined exceptions */
typedef char caml_generated_constant[256];
/* We claim these constants are big so that e.g. the Mips compiler
will not assume that they are in the .sdata section */
extern caml_generated_constant Out_of_memory, Sys_error, Failure,
Invalid_argument, End_of_file, Division_by_zero, Not_found, Match_failure;
/* Exception raising */
extern void raise_caml_exception P((value bucket)) Noreturn;
extern char * caml_exception_pointer;
void mlraise(v)
value v;
{
#ifdef POSIX_SIGNALS
sigset_t mask;
sigemptyset(&mask);
sigprocmask(SIG_SETMASK, &mask, NULL);
#else
sigsetmask(0);
#endif
leave_blocking_section();
#ifndef Stack_grows_upwards
while (local_roots != NULL &&
(char *) local_roots < caml_exception_pointer) {
#else
while (local_roots != NULL &&
(char *) local_roots > caml_exception_pointer) {
#endif
local_roots = (value *) local_roots[1];
}
raise_caml_exception(v);
}
void raise_constant(tag)
value tag;
{
value bucket;
Push_roots (a, 1);
a[0] = tag;
bucket = alloc (1, 0);
Field(bucket, 0) = a[0];
Pop_roots ();
mlraise(bucket);
}
void raise_with_arg(tag, arg)
value tag;
value arg;
{
value bucket;
Push_roots (a, 2);
a[0] = tag;
a[1] = arg;
bucket = alloc (2, 0);
Field(bucket, 0) = a[0];
Field(bucket, 1) = a[1];
Pop_roots ();
mlraise(bucket);
}
void raise_with_string(tag, msg)
value tag;
char * msg;
{
raise_with_arg(tag, copy_string(msg));
}
void failwith (msg)
char * msg;
{
raise_with_string((value) Failure, msg);
}
/* We chose to abort the program if a C primitive raises Invalid_argument.
Rationale: nobody should trap Invalid_argument, and we're not running
under a toplevel, so this will provide the same feedback to the user.
Moreover, divisions by zero or out-of-bounds accesses also abort the
program, and there's no way we can turn them into exceptions.
Finally, this allows a number of C primitives to be declared "noalloc",
and this makes calling them much more efficient. */
void invalid_argument (msg)
char * msg;
{
fatal_error_arg("Fatal_error: Invalid_argument \"%s\"\n", msg);
}
/* To raise Out_of_memory, we can't use raise_constant,
because it allocates and we're out of memory...
We therefore build the bucket by hand.
This works OK because the exception value for Out_of_memory is also
statically allocated out of the heap. */
static struct {
header_t hdr;
value exn;
} out_of_memory_bucket;
void raise_out_of_memory()
{
out_of_memory_bucket.hdr = Make_header(1, 0, White);
out_of_memory_bucket.exn = (value) Out_of_memory;
mlraise((value) &(out_of_memory_bucket.exn));
}
void raise_sys_error(msg)
value msg;
{
raise_with_arg((value) Sys_error, msg);
}
void raise_end_of_file()
{
raise_constant((value) End_of_file);
}
void raise_zero_divide()
{
raise_constant((value) Division_by_zero);
}
void raise_not_found()
{
raise_constant((value) Not_found);
}
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