tor-browser

The Tor Browser
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jsexn.h (5511B)


      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
      2 * vim: set ts=8 sts=2 et sw=2 tw=80:
      3 * This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 /*
      8 * JS runtime exception classes.
      9 */
     10 
     11 #ifndef jsexn_h
     12 #define jsexn_h
     13 
     14 #include "mozilla/Assertions.h"
     15 
     16 #include "jspubtd.h"
     17 #include "jstypes.h"
     18 #include "NamespaceImports.h"
     19 
     20 #include "js/ErrorReport.h"
     21 #include "js/Exception.h"
     22 #include "js/friend/ErrorMessages.h"  // JSErr_Limit
     23 #include "js/RootingAPI.h"
     24 #include "js/TypeDecls.h"
     25 #include "js/UniquePtr.h"
     26 #include "js/Utility.h"
     27 
     28 extern const JSErrorFormatString js_ErrorFormatString[JSErr_Limit];
     29 
     30 namespace js {
     31 
     32 class ErrorObject;
     33 
     34 UniquePtr<JSErrorNotes::Note> CopyErrorNote(JSContext* cx,
     35                                            JSErrorNotes::Note* note);
     36 
     37 UniquePtr<JSErrorReport> CopyErrorReport(JSContext* cx, JSErrorReport* report);
     38 
     39 // Cut off the stack if it gets too deep (most commonly for infinite recursion
     40 // errors).
     41 static const size_t MAX_REPORTED_STACK_DEPTH = 1u << 7;
     42 
     43 bool CaptureStack(JSContext* cx, MutableHandleObject stack);
     44 
     45 JSString* ComputeStackString(JSContext* cx);
     46 
     47 /*
     48 * Given a JSErrorReport, check to see if there is an exception associated with
     49 * the error number.  If there is, then create an appropriate Error object,
     50 * set it as the pending exception.
     51 *
     52 * It's possible we fail (due to OOM or some other error) and end up setting
     53 * JSContext::unwrappedException to a different exception.
     54 * The original error described by reportp typically won't be reported anywhere
     55 * in this case.
     56 *
     57 * Returns true if the error was converted to an exception. If the error code
     58 * is unrecognized, we fail due to OOM, or if we decided to do nothing in order
     59 * to avoid recursion, we return false and this error is just being swept under
     60 * the rug.
     61 */
     62 extern bool ErrorToException(JSContext* cx, JSErrorReport* reportp,
     63                             JSErrorCallback callback, void* userRef);
     64 
     65 extern JSErrorReport* ErrorFromException(JSContext* cx, HandleObject obj);
     66 
     67 /*
     68 * Make a copy of errobj parented to cx's compartment's global.
     69 *
     70 * errobj may be in a different compartment than cx, but it must be an Error
     71 * object (not a wrapper of one) and it must not be one of the standard error
     72 * prototype objects (errobj->getPrivate() must not be nullptr).
     73 */
     74 extern JSObject* CopyErrorObject(JSContext* cx,
     75                                 JS::Handle<ErrorObject*> errobj);
     76 
     77 static_assert(
     78    JSEXN_ERR == 0 &&
     79        JSProto_Error + int(JSEXN_INTERNALERR) == JSProto_InternalError &&
     80        JSProto_Error + int(JSEXN_AGGREGATEERR) == JSProto_AggregateError &&
     81        JSProto_Error + int(JSEXN_EVALERR) == JSProto_EvalError &&
     82        JSProto_Error + int(JSEXN_RANGEERR) == JSProto_RangeError &&
     83        JSProto_Error + int(JSEXN_REFERENCEERR) == JSProto_ReferenceError &&
     84 #ifdef ENABLE_EXPLICIT_RESOURCE_MANAGEMENT
     85        JSProto_Error + int(JSEXN_SUPPRESSEDERR) == JSProto_SuppressedError &&
     86 #endif
     87        JSProto_Error + int(JSEXN_SYNTAXERR) == JSProto_SyntaxError &&
     88        JSProto_Error + int(JSEXN_TYPEERR) == JSProto_TypeError &&
     89        JSProto_Error + int(JSEXN_URIERR) == JSProto_URIError &&
     90        JSProto_Error + int(JSEXN_DEBUGGEEWOULDRUN) ==
     91            JSProto_DebuggeeWouldRun &&
     92        JSProto_Error + int(JSEXN_WASMCOMPILEERROR) == JSProto_CompileError &&
     93        JSProto_Error + int(JSEXN_WASMLINKERROR) == JSProto_LinkError &&
     94        JSProto_Error + int(JSEXN_WASMRUNTIMEERROR) == JSProto_RuntimeError &&
     95 #ifdef ENABLE_WASM_JSPI
     96        JSProto_Error + int(JSEXN_WASMSUSPENDERROR) == JSProto_SuspendError &&
     97        JSEXN_WASMSUSPENDERROR + 1 == JSEXN_WARN &&
     98 #else
     99        JSEXN_WASMRUNTIMEERROR + 1 == JSEXN_WARN &&
    100 #endif
    101        JSEXN_WARN + 1 == JSEXN_NOTE && JSEXN_NOTE + 1 == JSEXN_LIMIT,
    102    "GetExceptionProtoKey and ExnTypeFromProtoKey require that "
    103    "each corresponding JSExnType and JSProtoKey value be separated "
    104    "by the same constant value");
    105 
    106 static inline constexpr JSProtoKey GetExceptionProtoKey(JSExnType exn) {
    107  MOZ_ASSERT(JSEXN_ERR <= exn);
    108  MOZ_ASSERT(exn < JSEXN_WARN);
    109  return JSProtoKey(JSProto_Error + int(exn));
    110 }
    111 
    112 static inline JSExnType ExnTypeFromProtoKey(JSProtoKey key) {
    113  JSExnType type = static_cast<JSExnType>(key - JSProto_Error);
    114  MOZ_ASSERT(type >= JSEXN_ERR);
    115  MOZ_ASSERT(type < JSEXN_ERROR_LIMIT);
    116  return type;
    117 }
    118 
    119 static inline bool IsErrorProtoKey(JSProtoKey key) {
    120  int type = key - JSProto_Error;
    121  return type >= JSEXN_ERR && type < JSEXN_ERROR_LIMIT;
    122 }
    123 
    124 class AutoClearPendingException {
    125  JSContext* cx;
    126 
    127 public:
    128  explicit AutoClearPendingException(JSContext* cxArg) : cx(cxArg) {}
    129 
    130  ~AutoClearPendingException() { JS_ClearPendingException(cx); }
    131 };
    132 
    133 // Convert the given value to a string for use in an error message. This
    134 // function never returns nullptr and never reports an exception.
    135 extern const char* ValueToSourceForError(JSContext* cx, HandleValue val,
    136                                         JS::UniqueChars& bytes);
    137 
    138 bool GetInternalError(JSContext* cx, unsigned errorNumber,
    139                      MutableHandleValue error);
    140 bool GetTypeError(JSContext* cx, unsigned errorNumber,
    141                  MutableHandleValue error);
    142 bool GetAggregateError(JSContext* cx, unsigned errorNumber,
    143                       MutableHandleValue error);
    144 
    145 }  // namespace js
    146 
    147 #endif /* jsexn_h */