Mercurial > cpython-lru_cache-weakref

comparison Python/errors.c @ 86:a6934380c6e7 legacy-trunk

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
"Compiling" version
author Guido van Rossum <guido@python.org>
date Thu, 20 Dec 1990 15:06:42 +0000
parents 46cb14aec10a
children 5cb843bc87fc
comparison
equal deleted inserted replaced
85:06c92f491f58 86:a6934380c6e7
9 The old convention was to set 'errno' and to return NULL. 9 The old convention was to set 'errno' and to return NULL.
10 The caller (usually call_function() in eval.c) detects the NULL 10 The caller (usually call_function() in eval.c) detects the NULL
11 return value and then calls puterrno(ctx) to turn the errno value 11 return value and then calls puterrno(ctx) to turn the errno value
12 into a true exception. Problems with this approach are: 12 into a true exception. Problems with this approach are:
13 - it used standard errno values to indicate Python-specific errors, 13 - it used standard errno values to indicate Python-specific errors,
14 but this means that when such an error code is reported by UNIX the 14 but this means that when such an error code is reported by a system
15 user gets a confusing message 15 call (e.g., in module posix), the user gets a confusing message
16 - errno is a global variable, which makes extensions to a multi- 16 - errno is a global variable, which makes extensions to a multi-
17 threading environment difficult; e.g., in IRIX, multi-threaded 17 threading environment difficult; e.g., in IRIX, multi-threaded
18 programs must use the function getoserror() (sp.?) instead of 18 programs must use the function oserror() instead of looking in errno
19 looking in errno
20 - there is no portable way to add new error numbers for specic 19 - there is no portable way to add new error numbers for specic
21 situations -- the value space for errno is reserved to the OS, yet 20 situations -- the value space for errno is reserved to the OS, yet
22 the way to turn module-specific errors into a module-specific 21 the way to turn module-specific errors into a module-specific
23 exception requires module-specific values for errno 22 exception requires module-specific values for errno
24 - there is no way to add a more situation-specific message to an 23 - there is no way to add a more situation-specific message to an
25 error. 24 error.
26 25
27 The new interface solves all these problems. To return an error, a 26 The new interface solves all these problems. To return an error, a
28 built-in function calls err_set(exception), err_set(valexception, 27 built-in function calls err_set(exception), err_setval(exception,
29 value) or err_setstr(exception, string), and returns NULL. These 28 value) or err_setstr(exception, string), and returns NULL. These
30 functions save the value for later use by puterrno(). To adapt this 29 functions save the value for later use by puterrno(). To adapt this
31 scheme to a multi-threaded environment, only the implementation of 30 scheme to a multi-threaded environment, only the implementation of
32 err_setval() has to be changed. 31 err_setval() has to be changed.
33 */ 32 */
34 33
35 #include <stdio.h> 34 #include "errno.h"
36 35
37 #include "PROTO.h" 36 #include "allobjects.h"
38 #include "object.h" 37
39 #include "intobject.h" 38 #include "errcode.h"
40 #include "stringobject.h"
41 #include "tupleobject.h"
42 #include "errors.h"
43 39
44 extern char *strerror PROTO((int)); 40 extern char *strerror PROTO((int));
45 41
46 /* Last exception stored by err_setval() */ 42 /* Last exception stored by err_setval() */
47 43
51 void 47 void
52 err_setval(exception, value) 48 err_setval(exception, value)
53 object *exception; 49 object *exception;
54 object *value; 50 object *value;
55 { 51 {
56 if (last_exception != NULL) 52 XDECREF(last_exception);
57 DECREF(last_exception); 53 XINCREF(exception);
58 if (exception != NULL)
59 INCREF(exception);
60 last_exception = exception; 54 last_exception = exception;
61 55
62 if (last_exc_val != NULL) 56 XDECREF(last_exc_val);
63 DECREF(last_exc_val); 57 XINCREF(value);
64 if (value != NULL)
65 INCREF(value);
66 last_exc_val = value; 58 last_exc_val = value;
67 } 59 }
68 60
69 void 61 void
70 err_set(exception) 62 err_set(exception)
78 object *exception; 70 object *exception;
79 char *string; 71 char *string;
80 { 72 {
81 object *value = newstringobject(string); 73 object *value = newstringobject(string);
82 err_setval(exception, value); 74 err_setval(exception, value);
83 if (value != NULL) 75 XDECREF(value);
84 DECREF(value);
85 } 76 }
86 77
87 int 78 int
88 err_occurred() 79 err_occurred()
89 { 80 {
102 } 93 }
103 94
104 void 95 void
105 err_clear() 96 err_clear()
106 { 97 {
107 if (last_exception != NULL) { 98 XDECREF(last_exception);
108 DECREF(last_exception); 99 last_exception = NULL;
109 last_exception = NULL; 100 XDECREF(last_exc_val);
110 } 101 last_exc_val = NULL;
111 if (last_exc_val != NULL) {
112 DECREF(last_exc_val);
113 last_exc_val = NULL;
114 }
115 } 102 }
116 103
117 /* Convenience functions to set a type error exception and return 0 */ 104 /* Convenience functions to set a type error exception and return 0 */
118 105
119 int 106 int
124 } 111 }
125 112
126 object * 113 object *
127 err_nomem() 114 err_nomem()
128 { 115 {
129 err_setstr(MemoryError, "in built-in function"); 116 err_set(MemoryError);
130 return NULL; 117 return NULL;
131 } 118 }
132 119
133 object * 120 object *
134 err_errno(exc) 121 err_errno(exc)
138 if (v != NULL) { 125 if (v != NULL) {
139 settupleitem(v, 0, newintobject((long)errno)); 126 settupleitem(v, 0, newintobject((long)errno));
140 settupleitem(v, 1, newstringobject(strerror(errno))); 127 settupleitem(v, 1, newstringobject(strerror(errno)));
141 } 128 }
142 err_setval(exc, v); 129 err_setval(exc, v);
143 if (v != NULL) 130 XDECREF(v);
144 DECREF(v);
145 return NULL; 131 return NULL;
146 } 132 }
147 133
148 void 134 void
149 err_badcall() 135 err_badcall()
150 { 136 {
151 err_setstr(SystemError, "bad argument to internal function"); 137 err_setstr(SystemError, "bad argument to internal function");
152 } 138 }
139
140 /* Set the error appropriate to the given input error code (see errcode.h) */
141
142 void
143 err_input(err)
144 int err;
145 {
146 switch (err) {
147 case E_DONE:
148 case E_OK:
149 break;
150 case E_SYNTAX:
151 err_setstr(RuntimeError, "syntax error");
152 break;
153 case E_TOKEN:
154 err_setstr(RuntimeError, "illegal token");
155 break;
156 case E_INTR:
157 err_set(KeyboardInterrupt);
158 break;
159 case E_NOMEM:
160 err_nomem();
161 break;
162 case E_EOF:
163 err_set(EOFError);
164 break;
165 default:
166 err_setstr(RuntimeError, "unknown input error");
167 break;
168 }
169 }