1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. Distributed only by permission. */
/* */
/***********************************************************************/
/* $Id$ */
/* Raising exceptions from C. */
#include <signal.h>
#include "alloc.h"
#include "fail.h"
#include "io.h"
#include "gc.h"
#include "memory.h"
#include "mlvalues.h"
#include "signals.h"
#include "stack.h"
#include "roots.h"
/* The globals holding predefined exceptions */
typedef value caml_generated_constant[1];
extern caml_generated_constant Out_of_memory, Sys_error, Failure,
Invalid_argument, End_of_file, Division_by_zero, Not_found,
Match_failure, Sys_blocked_io;
/* Exception raising */
extern void raise_caml_exception (value bucket) Noreturn;
char * caml_exception_pointer = NULL;
void mlraise(value v)
{
Unlock_exn();
if (caml_exception_pointer == NULL) fatal_uncaught_exception(v);
#ifndef Stack_grows_upwards
#define PUSHED_AFTER <
#else
#define PUSHED_AFTER >
#endif
while (local_roots != NULL &&
(char *) local_roots PUSHED_AFTER caml_exception_pointer) {
local_roots = local_roots->next;
}
#undef PUSHED_AFTER
raise_caml_exception(v);
}
void raise_constant(value tag)
{
value bucket;
Begin_root (tag);
bucket = alloc_small (1, 0);
Field(bucket, 0) = tag;
End_roots ();
mlraise(bucket);
}
void raise_with_arg(value tag, value arg)
{
value bucket;
Begin_roots2 (tag, arg);
bucket = alloc_small (2, 0);
Field(bucket, 0) = tag;
Field(bucket, 1) = arg;
End_roots ();
mlraise(bucket);
}
void raise_with_string(value tag, char *msg)
{
raise_with_arg(tag, copy_string(msg));
}
void failwith (char *msg)
{
raise_with_string((value) Failure, msg);
}
void invalid_argument (char *msg)
{
raise_with_string((value) Invalid_argument, 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(void)
{
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(value msg)
{
raise_with_arg((value) Sys_error, msg);
}
void raise_end_of_file(void)
{
raise_constant((value) End_of_file);
}
void raise_zero_divide(void)
{
raise_constant((value) Division_by_zero);
}
void raise_not_found(void)
{
raise_constant((value) Not_found);
}
void raise_sys_blocked_io(void)
{
raise_constant((value) Sys_blocked_io);
}
/* We allocate statically the bucket for the exception because we can't
do a GC before the exception is raised (lack of stack descriptors
for the ccall to array_bound_error */
#define BOUND_MSG "out-of-bound array or string access"
#define BOUND_MSG_LEN (sizeof(BOUND_MSG) - 1)
static struct {
header_t hdr;
value exn;
value arg;
} array_bound_error_bucket;
static struct {
header_t hdr;
char data[BOUND_MSG_LEN + sizeof(value)];
} array_bound_error_msg = { 0, BOUND_MSG };
void array_bound_error(void)
{
mlsize_t wosize = (BOUND_MSG_LEN + sizeof(value)) / sizeof(value);
mlsize_t offset_index = Bsize_wsize(wosize) - 1;
array_bound_error_msg.hdr = Make_header(wosize, String_tag, White);
array_bound_error_msg.data[offset_index] = offset_index - BOUND_MSG_LEN;
array_bound_error_bucket.hdr = Make_header(2, 0, White);
array_bound_error_bucket.exn = (value) Invalid_argument;
array_bound_error_bucket.arg = (value) array_bound_error_msg.data;
mlraise((value) &array_bound_error_bucket.exn);
}
|
