aboutsummaryrefslogtreecommitdiffstats
path: root/components/script/dom/bindings/error.rs
blob: a5fb6d90e5176ddba4f793523071e5307e7ba1d7 (plain) (blame)
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
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

//! Utilities to throw exceptions from Rust bindings.

use dom::bindings::codegen::PrototypeList::proto_id_to_name;
use dom::bindings::conversions::ToJSValConvertible;
use dom::bindings::global::GlobalRef;
use dom::domexception::{DOMException, DOMErrorName};

use util::mem::HeapSizeOf;
use util::str::DOMString;

use js::jsapi::JSAutoCompartment;
use js::jsapi::{JSContext, JSObject, RootedValue};
use js::jsapi::{JS_IsExceptionPending, JS_SetPendingException, JS_ReportPendingException};
use js::jsapi::{JS_ReportErrorNumber1, JSErrorFormatString, JSExnType};
use js::jsapi::{JS_SaveFrameChain, JS_RestoreFrameChain};
use js::jsval::UndefinedValue;

use libc;
use std::ffi::CString;
use std::mem;
use std::ptr;

/// DOM exceptions that can be thrown by a native DOM method.
#[derive(Debug, Clone, HeapSizeOf)]
pub enum Error {
    /// IndexSizeError DOMException
    IndexSize,
    /// NotFoundError DOMException
    NotFound,
    /// HierarchyRequestError DOMException
    HierarchyRequest,
    /// WrongDocumentError DOMException
    WrongDocument,
    /// InvalidCharacterError DOMException
    InvalidCharacter,
    /// NotSupportedError DOMException
    NotSupported,
    /// InUseAttributeError DOMException
    InUseAttribute,
    /// InvalidStateError DOMException
    InvalidState,
    /// SyntaxError DOMException
    Syntax,
    /// NamespaceError DOMException
    Namespace,
    /// InvalidAccessError DOMException
    InvalidAccess,
    /// SecurityError DOMException
    Security,
    /// NetworkError DOMException
    Network,
    /// AbortError DOMException
    Abort,
    /// TimeoutError DOMException
    Timeout,
    /// InvalidNodeTypeError DOMException
    InvalidNodeType,
    /// DataCloneError DOMException
    DataClone,
    /// NoModificationAllowedError DOMException
    NoModificationAllowed,
    /// QuotaExceededError DOMException
    QuotaExceeded,
    /// TypeMismatchError DOMException
    TypeMismatch,

    /// TypeError JavaScript Error
    Type(DOMString),
    /// RangeError JavaScript Error
    Range(DOMString),

    /// A JavaScript exception is already pending.
    JSFailed,
}

/// The return type for IDL operations that can throw DOM exceptions.
pub type Fallible<T> = Result<T, Error>;

/// The return type for IDL operations that can throw DOM exceptions and
/// return `()`.
pub type ErrorResult = Fallible<()>;

/// Set a pending exception for the given `result` on `cx`.
pub fn throw_dom_exception(cx: *mut JSContext, global: GlobalRef,
                           result: Error) {
    let code = match result {
        Error::IndexSize => DOMErrorName::IndexSizeError,
        Error::NotFound => DOMErrorName::NotFoundError,
        Error::HierarchyRequest => DOMErrorName::HierarchyRequestError,
        Error::WrongDocument => DOMErrorName::WrongDocumentError,
        Error::InvalidCharacter => DOMErrorName::InvalidCharacterError,
        Error::NotSupported => DOMErrorName::NotSupportedError,
        Error::InUseAttribute => DOMErrorName::InUseAttributeError,
        Error::InvalidState => DOMErrorName::InvalidStateError,
        Error::Syntax => DOMErrorName::SyntaxError,
        Error::Namespace => DOMErrorName::NamespaceError,
        Error::InvalidAccess => DOMErrorName::InvalidAccessError,
        Error::Security => DOMErrorName::SecurityError,
        Error::Network => DOMErrorName::NetworkError,
        Error::Abort => DOMErrorName::AbortError,
        Error::Timeout => DOMErrorName::TimeoutError,
        Error::InvalidNodeType => DOMErrorName::InvalidNodeTypeError,
        Error::DataClone => DOMErrorName::DataCloneError,
        Error::NoModificationAllowed => DOMErrorName::NoModificationAllowedError,
        Error::QuotaExceeded => DOMErrorName::QuotaExceededError,
        Error::TypeMismatch => DOMErrorName::TypeMismatchError,
        Error::Type(message) => {
            assert!(unsafe { JS_IsExceptionPending(cx) } == 0);
            throw_type_error(cx, &message);
            return;
        },
        Error::Range(message) => {
            assert!(unsafe { JS_IsExceptionPending(cx) } == 0);
            throw_range_error(cx, &message);
            return;
        },
        Error::JSFailed => {
            assert!(unsafe { JS_IsExceptionPending(cx) } == 1);
            return;
        }
    };

    assert!(unsafe { JS_IsExceptionPending(cx) } == 0);
    let exception = DOMException::new(global, code);
    let mut thrown = RootedValue::new(cx, UndefinedValue());
    exception.to_jsval(cx, thrown.handle_mut());
    unsafe {
        JS_SetPendingException(cx, thrown.handle());
    }
}

/// Report a pending exception, thereby clearing it.
pub fn report_pending_exception(cx: *mut JSContext, obj: *mut JSObject) {
    unsafe {
        if JS_IsExceptionPending(cx) != 0 {
            let saved = JS_SaveFrameChain(cx);
            {
                let _ac = JSAutoCompartment::new(cx, obj);
                JS_ReportPendingException(cx);
            }
            if saved != 0 {
                JS_RestoreFrameChain(cx);
            }
        }
    }
}

/// Throw an exception to signal that a `JSVal` can not be converted to any of
/// the types in an IDL union type.
pub fn throw_not_in_union(cx: *mut JSContext, names: &'static str) {
    assert!(unsafe { JS_IsExceptionPending(cx) } == 0);
    let error = format!("argument could not be converted to any of: {}", names);
    throw_type_error(cx, &error);
}

/// Throw an exception to signal that a `JSObject` can not be converted to a
/// given DOM type.
pub fn throw_invalid_this(cx: *mut JSContext, proto_id: u16) {
    debug_assert!(unsafe { JS_IsExceptionPending(cx) } == 0);
    let error = format!("\"this\" object does not implement interface {}.",
                        proto_id_to_name(proto_id));
    throw_type_error(cx, &error);
}

/// Format string used to throw javascript errors.
static ERROR_FORMAT_STRING_STRING: [libc::c_char; 4] = [
    '{' as libc::c_char,
    '0' as libc::c_char,
    '}' as libc::c_char,
    0 as libc::c_char,
];

/// Format string struct used to throw `TypeError`s.
static mut TYPE_ERROR_FORMAT_STRING: JSErrorFormatString = JSErrorFormatString {
    format: &ERROR_FORMAT_STRING_STRING as *const libc::c_char,
    argCount: 1,
    exnType: JSExnType::JSEXN_TYPEERR as i16,
};

/// Format string struct used to throw `RangeError`s.
static mut RANGE_ERROR_FORMAT_STRING: JSErrorFormatString = JSErrorFormatString {
    format: &ERROR_FORMAT_STRING_STRING as *const libc::c_char,
    argCount: 1,
    exnType: JSExnType::JSEXN_RANGEERR as i16,
};

/// Callback used to throw javascript errors.
/// See throw_js_error for info about error_number.
unsafe extern fn get_error_message(_user_ref: *mut libc::c_void,
                                   error_number: libc::c_uint)
    -> *const JSErrorFormatString
{
    let num: JSExnType = mem::transmute(error_number);
    match num {
      JSExnType::JSEXN_TYPEERR => &TYPE_ERROR_FORMAT_STRING as *const JSErrorFormatString,
      JSExnType::JSEXN_RANGEERR => &RANGE_ERROR_FORMAT_STRING as *const JSErrorFormatString,
      _ => panic!("Bad js error number given to get_error_message: {}", error_number)
    }
}

/// Helper fn to throw a javascript error with the given message and number.
/// Reuse the jsapi error codes to distinguish the error_number
/// passed back to the get_error_message callback.
/// c_uint is u32, so this cast is safe, as is casting to/from i32 from there.
fn throw_js_error(cx: *mut JSContext, error: &str, error_number: u32) {
    let error = CString::new(error).unwrap();
    unsafe {
        JS_ReportErrorNumber1(cx,
            Some(get_error_message),
            ptr::null_mut(), error_number, error.as_ptr());
    }
}

/// Throw a `TypeError` with the given message.
pub fn throw_type_error(cx: *mut JSContext, error: &str) {
    throw_js_error(cx, error, JSExnType::JSEXN_TYPEERR as u32);
}

/// Throw a `RangeError` with the given message.
pub fn throw_range_error(cx: *mut JSContext, error: &str) {
    throw_js_error(cx, error, JSExnType::JSEXN_RANGEERR as u32);
}