aboutsummaryrefslogtreecommitdiffstats
path: root/test/monniaux/ocaml/byterun/printexc.c
blob: 735c2994a15a02b8a569ae14d713fa36ca235d17 (plain)
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
/**************************************************************************/
/*                                                                        */
/*                                 OCaml                                  */
/*                                                                        */
/*             Xavier Leroy, projet Cristal, INRIA Rocquencourt           */
/*                                                                        */
/*   Copyright 1996 Institut National de Recherche en Informatique et     */
/*     en Automatique.                                                    */
/*                                                                        */
/*   All rights reserved.  This file is distributed under the terms of    */
/*   the GNU Lesser General Public License version 2.1, with the          */
/*   special exception on linking described in the file LICENSE.          */
/*                                                                        */
/**************************************************************************/

#define CAML_INTERNALS

/* Print an uncaught exception and abort */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "caml/backtrace.h"
#include "caml/callback.h"
#include "caml/debugger.h"
#include "caml/fail.h"
#include "caml/misc.h"
#include "caml/mlvalues.h"
#include "caml/printexc.h"
#include "caml/memory.h"

struct stringbuf {
  char * ptr;
  char * end;
  char data[256];
};

static void add_char(struct stringbuf *buf, char c)
{
  if (buf->ptr < buf->end) *(buf->ptr++) = c;
}

static void add_string(struct stringbuf *buf, const char *s)
{
  int len = strlen(s);
  if (buf->ptr + len > buf->end) len = buf->end - buf->ptr;
  if (len > 0) memmove(buf->ptr, s, len);
  buf->ptr += len;
}

CAMLexport char * caml_format_exception(value exn)
{
  mlsize_t start, i;
  value bucket, v;
  struct stringbuf buf;
  char intbuf[64];
  char * res;

  buf.ptr = buf.data;
  buf.end = buf.data + sizeof(buf.data) - 1;
  if (Tag_val(exn) == 0) {
    add_string(&buf, String_val(Field(Field(exn, 0), 0)));
    /* Check for exceptions in the style of Match_failure and Assert_failure */
    if (Wosize_val(exn) == 2 &&
        Is_block(Field(exn, 1)) &&
        Tag_val(Field(exn, 1)) == 0 &&
        caml_is_special_exception(Field(exn, 0))) {
      bucket = Field(exn, 1);
      start = 0;
    } else {
      bucket = exn;
      start = 1;
    }
    add_char(&buf, '(');
    for (i = start; i < Wosize_val(bucket); i++) {
      if (i > start) add_string(&buf, ", ");
      v = Field(bucket, i);
      if (Is_long(v)) {
        snprintf(intbuf, sizeof(intbuf),
                 "%" ARCH_INTNAT_PRINTF_FORMAT "d", Long_val(v));
        add_string(&buf, intbuf);
      } else if (Tag_val(v) == String_tag) {
        add_char(&buf, '"');
        add_string(&buf, String_val(v));
        add_char(&buf, '"');
      } else {
        add_char(&buf, '_');
      }
    }
    add_char(&buf, ')');
  } else
    add_string(&buf, String_val(Field(exn, 0)));

  *buf.ptr = 0;              /* Terminate string */
  i = buf.ptr - buf.data + 1;
  res = caml_stat_alloc_noexc(i);
  if (res == NULL) return NULL;
  memmove(res, buf.data, i);
  return res;
}


#ifdef NATIVE_CODE
#  define DEBUGGER_IN_USE 0
#else
#  define DEBUGGER_IN_USE caml_debugger_in_use
#endif

/* Default C implementation in case the OCaml one is not registered. */
static void default_fatal_uncaught_exception(value exn)
{
  char * msg;
  value * at_exit;
  int saved_backtrace_active, saved_backtrace_pos;

  /* Build a string representation of the exception */
  msg = caml_format_exception(exn);
  /* Perform "at_exit" processing, ignoring all exceptions that may
     be triggered by this */
  saved_backtrace_active = caml_backtrace_active;
  saved_backtrace_pos = caml_backtrace_pos;
  caml_backtrace_active = 0;
  at_exit = caml_named_value("Pervasives.do_at_exit");
  if (at_exit != NULL) caml_callback_exn(*at_exit, Val_unit);
  caml_backtrace_active = saved_backtrace_active;
  caml_backtrace_pos = saved_backtrace_pos;
  /* Display the uncaught exception */
  fprintf(stderr, "Fatal error: exception %s\n", msg);
  caml_stat_free(msg);
  /* Display the backtrace if available */
  if (caml_backtrace_active && !DEBUGGER_IN_USE)
    caml_print_exception_backtrace();
}

int caml_abort_on_uncaught_exn = 0; /* see afl.c */

void caml_fatal_uncaught_exception(value exn)
{
  value *handle_uncaught_exception;

  handle_uncaught_exception =
    caml_named_value("Printexc.handle_uncaught_exception");
  if (handle_uncaught_exception != NULL)
    /* [Printexc.handle_uncaught_exception] does not raise exception. */
    caml_callback2(*handle_uncaught_exception, exn, Val_bool(DEBUGGER_IN_USE));
  else
    default_fatal_uncaught_exception(exn);
  /* Terminate the process */
  if (caml_abort_on_uncaught_exn) {
    abort();
  } else {
    CAML_SYS_EXIT(2);
    exit(2); /* Second exit needed for the Noreturn flag */
  }
}